Liquid discharge head and liquid discharge device

Abstract

To provide a liquid discharge head that can detect pressure of an absorption chamber in the vicinity of a pressure chamber.SOLUTION: The liquid discharge head comprises: a nozzle substrate provided with a nozzle that discharges liquid; a pressure chamber substrate that includes a pressure chamber in which pressure for making the nozzle discharge liquid is applied to liquid and an absorption chamber, arranged adjacent in a second direction to the pressure chamber, which absorbs vibration of liquid that is generated when pressure is applied to liquid in the pressure chamber; a first vibration plate, provided to correspond to the pressure chamber, which vibrates to apply pressure to liquid; a second vibration plate, provided to correspond to the absorption chamber, which vibrates to absorb pressure of liquid; a second wiring part provided at a position corresponding to the absorption chamber; and a pressure obtaining part that obtains pressure of the absorption chamber, on the basis of a resistance value of the second wiring part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus. [Background technology]

[0002] Liquid ejection devices equipped with multiple heads that eject liquid such as ink onto a medium such as printing paper have been proposed. In recent years, inkjet printers have been attracting attention not only for printing purposes but also as devices that can apply liquefied materials to any location. Inkjet printers are equipped with liquid ejection heads that eject liquid. As a liquid ejection head, a head that ejects liquid filled in a pressure chamber from a nozzle by vibrating a vibration plate that constitutes the wall surface of the pressure chamber using a piezoelectric element is known.

[0003] The liquid ejection head described in Patent Document 1 has a pressure chamber and a liquid storage chamber provided at a position different from the pressure chamber. By providing the liquid storage chamber, pressure fluctuations caused by the liquid can be effectively absorbed, thereby improving the stability of ejection of liquid from the nozzles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-153926 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the liquid ejection head described in Patent Document 1, the pressure chamber and the liquid storage chamber are provided at positions separated from each other via many members. Therefore, the efficiency of absorbing liquid vibrations in the pressure chamber is low. It is believed that the efficiency of absorbing liquid vibrations can be improved by providing a liquid storage chamber at a position adjacent to the pressure chamber.

[0006] However, in a liquid ejection head, the behavior of the liquid changes significantly depending on the pressure of the pressure chamber. For this reason, acquiring the pressure has been a challenge. The inventors have discovered a configuration in which the liquid storage chamber is provided adjacent to the above-mentioned pressure chamber, and the pressure in the vicinity of the pressure chamber can be detected with a simple configuration by utilizing the liquid storage chamber. [Means for solving the problem]

[0007] A liquid ejection head according to a preferred aspect of the present invention has a nozzle substrate provided with a nozzle for ejecting liquid, a pressure chamber substrate having a pressure chamber in which pressure is applied to the liquid to eject the liquid from the nozzle, and an absorption chamber adjacent to the pressure chamber in a second direction and absorbing vibrations of the liquid generated when pressure is applied to the liquid in the pressure chamber, a first vibration plate provided corresponding to the pressure chamber and vibrating to apply pressure to the liquid, a second vibration plate provided corresponding to the absorption chamber and vibrating to absorb the pressure of the liquid, a second wiring portion provided at a position corresponding to the absorption chamber, and a pressure acquisition portion that acquires the pressure of the absorption chamber based on the resistance value of the second wiring portion. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of a liquid ejection device according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram of the liquid ejection device of FIG. [Diagram 3] 2 is a cross-sectional view of a portion of the liquid ejection head shown in FIG. [Figure 4] 4 is a diagram showing a part of the pressure chamber substrate in FIG. 3. [Diagram 5] 4 is a cross-sectional view of a first piezoelectric element, a first wiring portion, and a second wiring portion in FIG. 3. [Figure 6] 4 is a diagram showing a part of the first piezoelectric element in FIG. 3. [Figure 7] 3 is a diagram showing a second electrode, a first wiring portion, and a second wiring portion in FIG. 2. FIG. [Figure 8] 3 is a diagram showing a bridge circuit included in the pressure detection unit of FIG. 2. [Figure 9]3 is a diagram showing a part of the temperature detection unit in FIG. 2. [Figure 10] FIG. 11 is a diagram illustrating a first wiring portion according to a second embodiment. [Figure 11] FIG. 13 is a diagram illustrating a first wiring portion according to a third embodiment. [Figure 12] FIG. 11 is a block diagram of a liquid ejection device according to a modified example. [Figure 13] FIG. 11 is a cross-sectional view of a portion of a liquid ejection head according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Note that the dimensions or scale of each part in the drawings may differ from the actual dimensions, and some parts are shown diagrammatically to facilitate understanding. The scope of the present invention is not limited to these forms unless otherwise specified in the following description to the effect that the present invention is limited. Furthermore, "element β on element γ" is not limited to a configuration in which element γ and element β are in direct contact with each other, and also includes a configuration in which element γ and element β are not in direct contact with each other. "Element γ and element β are the same" means that element γ and element β are substantially the same, and includes manufacturing errors and the like.

[0010] 1. First embodiment 1-1. Overall configuration of the liquid ejection device 100 1 is a schematic diagram illustrating the configuration of a liquid ejection device 100 according to a first embodiment. In the following, for convenience of explanation, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other will be appropriately used. Moreover, one direction along the X-axis will be referred to as the X1 direction, and the direction opposite to the X1 direction will be referred to as the X2 direction. Similarly, one direction along the Y-axis will be referred to as the Y1 direction, and the direction opposite to the Y1 direction will be referred to as the Y2 direction. One direction along the Z-axis will be referred to as the Z1 direction, and the direction opposite to the Z1 direction will be referred to as the Z2 direction.

[0011] The liquid ejection device 100 in Fig. 1 is an inkjet printing device that ejects ink, which is an example of a liquid, onto a medium 90. The medium 90 is typically printing paper, but any printing target made of any material, such as a resin film or fabric, can be used as the medium 90. As illustrated in Fig. 1, the liquid ejection device 100 is provided with a liquid container 9 that stores ink. For example, a cartridge that can be detachably attached to the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, or an ink tank that can be refilled with ink can be used as the liquid container 9.

[0012] The liquid ejection device 100 includes a control unit 20, a medium transport mechanism 22, a moving mechanism 24, and a liquid ejection head 1. The control unit 20 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 performs overall control of each element of the liquid ejection device 100.

[0013] The medium transport mechanism 22 transports the medium 90 in a direction along the Y axis under the control of the control unit 20. The movement mechanism 24 reciprocates the liquid ejection head 1 along the X axis under the control of the control unit 20. The movement mechanism 24 includes a substantially box-shaped transport body 242 that houses the liquid ejection head 1, and a transport belt 244 to which the transport body 242 is fixed. Note that a configuration in which a plurality of liquid ejection heads 1 are mounted on the transport body 242, or a configuration in which the liquid container 9 is mounted on the transport body 242 together with the liquid ejection head 1, may also be employed.

[0014] The liquid ejection head 1 ejects ink supplied from a liquid container 9 from multiple nozzles onto a medium 90 under the control of a control unit 20. An image is formed on the surface of the medium 90 by each liquid ejection head 1 ejecting ink onto the medium 90 in parallel with the transport of the medium 90 by the medium transport mechanism 22 and the repeated reciprocating motion of the transport body 242.

[0015] Fig. 2 is a block diagram of the liquid ejection device 100 of Fig. 1. As shown in Fig. 2, the liquid ejection device 100 includes a control unit 20, a medium transport mechanism 22, a moving mechanism 24, and a liquid ejection head 1. The control unit 20 includes a control unit 21, a storage unit 23, and a drive signal generation circuit 25. The liquid ejection head 1 includes a drive circuit 40, a plurality of first piezoelectric elements 3, a temperature acquisition unit 41, a pressure acquisition unit 42, a temperature detection unit 5, and a pressure detection unit 6.

[0016] The control unit 21 includes one or more processing circuits, such as a CPU or an FPGA, etc. The control unit 21 generates signals for controlling the operation of each part of the liquid ejection device 100. The control unit 21 controls the ink ejection operation of the liquid ejection head 1.

[0017] The control unit 21 generates a print signal SI, a waveform designation signal dCom, and a timing signal PTS. The print signal SI is a digital signal for designating the type of operation of the liquid ejection head 1. The print signal SI designates whether or not to supply the drive signal Com to the first piezoelectric element 3. The waveform designation signal dCom is a digital signal that defines the waveform of the drive signal Com. The drive signal Com is an analog signal for driving the first piezoelectric element 3. The timing signal PTS is a signal that defines the generation timing of the drive signal Com.

[0018] The storage unit 23 includes one or more storage circuits such as semiconductor memories. The storage unit 23 stores print data Img supplied from the host computer. The storage unit 23 stores a control program for the liquid ejection device 100.

[0019] The drive signal generating circuit 25 includes a DA conversion circuit. The drive signal generating circuit 25 generates a drive signal Com having a waveform defined by a waveform designation signal dCom. The drive signal generating circuit 25 outputs the drive signal Com every time it receives a timing signal PTS.

[0020] The drive circuit 40 switches whether or not to supply the drive signal Com to each first piezoelectric element 3 based on the print signal SI. The drive circuit 40 selects the first piezoelectric element 3 to which the drive signal Com is supplied based on the print signal SI, latch signal LAT, and change signal CH supplied from the control unit 20. The latch signal LAT defines the latch timing of the print data Img. The change signal CH defines the selection timing of the drive pulse included in the drive signal Com.

[0021] The temperature acquisition unit 41 acquires the temperature of an absorption chamber S2 of the liquid ejection head 1, which will be described later, based on the resistance value of a first wiring portion 50 of the temperature detection unit 5. The pressure acquisition unit 42 acquires the pressure of the absorption chamber S2 based on the resistance value of a second wiring portion 60 of the pressure detection unit 6.

[0022] 1-2. Liquid ejection head 1 FIG. 3 is a cross-sectional view of a portion of the liquid ejection head 1 shown in FIG. 1, and is a cross-sectional view parallel to the XZ plane. The Z axis is an axis along the direction in which ink is ejected by the liquid ejection head 1. The direction along the Z axis is defined as the "vertical direction". The Z2 direction is an example of "one side in the vertical direction", and the Z1 direction is an example of "the other side in the vertical direction". In addition, a view from a direction along the Z axis intersecting with the Y2 direction and the X2 direction is defined as a "planar view". The Y1 direction or the Y2 direction is an example of the "first direction". The X1 direction or the X2 direction is an example of the "second direction".

[0023] The liquid ejection head 1 in Fig. 3 has a structure that is nearly symmetrical with respect to an imaginary plane a along the YZ plane. In the following explanation, the configuration on the right side of the imaginary plane a in Fig. 3 will be mainly explained, and the explanation of the configuration on the left side of the imaginary plane a in Fig. 3 will be omitted as appropriate.

[0024] The liquid ejection head 1 includes a nozzle substrate 11, a pressure chamber substrate 12, a vibration plate 13, a sealing substrate 14, a wiring substrate 49, a first piezoelectric element 3, a pressure detection unit 6, and a temperature detection unit 5. The first piezoelectric element 3 includes a first piezoelectric body 31, a first electrode 32, and a second electrode 33. The pressure detection unit 6 includes a second wiring unit 60. The temperature detection unit 5 includes a first wiring unit 50. Although not shown in detail, the nozzle substrate 11, the pressure chamber substrate 12, the vibration plate 13, and the sealing substrate 14 are elongated plates aligned along the Y axis.

[0025] The nozzle substrate 11 is a plate-like member provided with a plurality of nozzles N that eject ink, which is an example of a liquid. Each of the plurality of nozzles N is a circular through-hole that ejects ink. The plurality of nozzles N are linearly arranged along the Y axis. The nozzle substrate 11 is manufactured by processing a semiconductor substrate, such as a silicon single crystal substrate.

[0026] The pressure chamber substrate 12 is a flow path structure in which a flow path for supplying ink to each of the multiple nozzles N is formed. The pressure chamber substrate 12 is a laminate of a first substrate 121 and a second substrate 122. Each of the first substrate 121 and the second substrate 122 is manufactured by processing a semiconductor substrate such as a silicon single crystal substrate. The first substrate 121 and the second substrate 122 may be formed integrally. The pressure chamber substrate 12 may also include members other than the first substrate 121 and the second substrate 122.

[0027] Ink flow paths are formed in the pressure chamber substrate 12. Specifically, a plurality of pressure chambers S1, an absorption chamber S2, a plurality of first communication paths R1, and a second communication path R2 are formed in the pressure chamber substrate 12. Each of the first substrate 121 and the second substrate 122 has a recess or a through hole, and the recess or the through hole forms the plurality of pressure chambers S1, the absorption chamber S2, the plurality of first communication paths R1, and the second communication paths R2.

[0028] FIG. 4 is a diagram showing a part of the pressure chamber substrate 12 of FIG. 3. As shown in FIG. 4, each pressure chamber S1 has an elongated shape extending in the X2 direction. The multiple pressure chambers S1 are spaced apart from each other and lined up in the Y2 direction. Therefore, the direction in which the multiple pressure chambers S1 are lined up is the Y2 direction, which is the "first direction." Furthermore, the multiple pressure chambers S1 are provided in a one-to-one correspondence with the multiple nozzles N. Each pressure chamber S1 is a space in which pressure is applied to ink to eject ink from the nozzle N.

[0029] The multiple first communication channels R1 are spaced apart from each other and lined up in the Y2 direction. The multiple first communication channels R1 are provided in a one-to-one correspondence with the multiple pressure chambers S1. Each first communication channel R1 communicates the corresponding pressure chamber S1 with the nozzle N. Each first communication channel R1 overlaps with the corresponding pressure chamber S1 and nozzle N in a plan view.

[0030] The absorption chamber S2 is provided upstream of the pressure chambers S1. The pressure chambers S1 and the absorption chambers S2 are arranged in the X2 direction, which is the "second direction". The absorption chamber S2 has a longitudinal shape extending in the Y2 direction. The volume of the absorption chamber S2 is much larger than the volume of each pressure chamber S1. The absorption chamber S2 is provided in common to the pressure chambers S1, and is connected to the pressure chambers S1 via a plurality of communication channels S0. The absorption chamber S2 is adjacent to the pressure chamber S1, and absorbs ink vibrations that occur when pressure is applied to the ink in the pressure chamber S1. By providing the absorption chamber S2, the ink ejection performance can be stabilized. In addition, by the absorption chamber S2 being adjacent to the pressure chamber S1, the efficiency of absorbing ink vibrations can be increased compared to when the absorption chambers S2 are spaced apart. Therefore, the stability of the ink ejection performance can be increased.

[0031] The second communication channel R2 is provided upstream of the absorption chamber S2 and is connected to the absorption chamber S2. The second communication channel R2 has an elongated shape extending in the Y2 direction.

[0032] As shown in Fig. 3, a vibration plate 13 is disposed on the surface in the Z2 direction of the pressure chamber substrate 12. The thickness of the vibration plate 13 is much thinner than the thicknesses of the first substrate 121 and the second substrate 122 of the pressure chamber substrate 12. The thickness is the length in the Z1 direction. The vibration plate 13 is elastically deformable. The vibration plate 13 includes a plurality of first vibration plates 131 and second vibration plates 132. The plurality of first vibration plates 131 and second vibration plates 132 are formed from a single member.

[0033] The multiple first diaphragms 131 are provided in a one-to-one correspondence with the multiple pressure chambers S1. Each of the first diaphragms 131 is a portion of the diaphragm 13 that overlaps with the multiple pressure chambers S1 in a plan view. Each of the first diaphragms 131 forms a part of the pressure chamber S1. When a voltage is applied to the first piezoelectric body 31 of the first piezoelectric element 3, each of the first diaphragms 131 vibrates to apply pressure to the pressure chamber S1. Therefore, the first diaphragms 131 are provided corresponding to the pressure chambers S1, and vibrate to apply pressure to the ink.

[0034] The second diaphragm 132 is a portion of the diaphragm 13 that overlaps with the absorption chamber S2 in a plan view. The second diaphragm 132 forms a part of the absorption chamber S2. The second diaphragm 132 is provided in correspondence with the absorption chamber S2, and vibrates to absorb the pressure of the ink. The second diaphragm 132 vibrates when pressure is applied from the absorption chamber S2, and applies pressure to the second wiring part 60 arranged on the second diaphragm 132.

[0035] Furthermore, the multiple first diaphragms 131 and the multiple second diaphragms 132 are not separated, but are formed from a continuous member. This makes it easy to arrange the first diaphragms 131 and the second diaphragms 132 adjacent to each other. This also makes it easy to arrange the multiple pressure chambers S1 and the absorption chambers S2 adjacent to each other. Because the multiple pressure chambers S1 and the absorption chambers S2 can be arranged adjacent to each other, the efficiency of absorbing ink vibrations can be improved.

[0036] The diaphragm 13 is manufactured by processing a semiconductor substrate such as a silicon single crystal substrate. The diaphragm 13 may be formed by a part of the pressure chamber substrate 12. For example, the diaphragm 13 may be formed by thinning a part of the second substrate 122.

[0037] A sealing substrate 14 is disposed on the surface in the Z2 direction of the diaphragm 13. The sealing substrate 14 is a structure that protects a plurality of first piezoelectric elements 3 (to be described later) and reinforces the mechanical strength of the pressure chamber substrate 12.

[0038] The sealing substrate 14 is formed with a third communication flow path R3, a first space H1, and a space for wiring H0. The sealing substrate 14 has a recess or a through hole, and each of the flow paths or spaces is formed by the recess or the through hole. The third communication flow path R3 and the space for wiring H0 are each a hole penetrating the sealing substrate 14. The first space H1 is a space surrounded by the recess formed in the sealing substrate 14.

[0039] The third communication flow path R3 overlaps with the second communication flow path R2 in plan view and is connected to the second communication flow path R2. The third communication flow path R3 and the second communication flow path R2 form a common ink chamber R0. The common ink chamber R0 functions as a reservoir. A filter 141 is provided in the portion overlapping with the common ink chamber R0 in plan view to remove air bubbles and foreign matter that may get mixed in with the ink. The filter 141 may be omitted.

[0040] Although not shown, the first space H1, the third communication channel R3, and the wiring space H0 each have a longitudinal shape extending in the Y2 direction. The wiring space H0, the first space H1, and the third communication channel R3 are aligned in this order in the X2 direction.

[0041] 3, a plurality of first piezoelectric elements 3, a first wiring portion 50, and a second wiring portion 60 are arranged in the first space H1. A wiring board 49 is arranged in the wiring space H0. The wiring board 49 is joined to the pressure chamber substrate 12. The wiring board 49 is a mounting component on which a plurality of wires are formed for electrically connecting the control unit 20 and the liquid ejection head 1. For example, a TCP (Tape Carrier Package) or an FPC (Flexible Printed Circuit) is used as the wiring board 49.

[0042] Fig. 5 is a cross-sectional view of a portion of the first piezoelectric element 3, the first wiring portion 50, and the second wiring portion 60 in Fig. 3. The first piezoelectric element 3, the first wiring portion 50, and the second wiring portion 60 are disposed on the vibration plate 13. The first piezoelectric element 3 is disposed mainly on the first vibration plate 131, and is located above the pressure chamber S1. The second wiring portion 60 is disposed on the second vibration plate 132, and is located above the absorption chamber S2. The first wiring portion 50 does not overlap the multiple pressure chambers S1 and the absorption chambers S2 in a plan view.

[0043] The first piezoelectric element 3 is disposed on the surface of the first vibration plate 131 opposite to the pressure chamber S1. The first piezoelectric element 3 has an elongated shape extending in the X2 direction. The first piezoelectric element 3 is provided corresponding to each pressure chamber S1, and one is provided for each pressure chamber S1. The multiple first piezoelectric elements 3 are spaced apart from each other and lined up in the Y2 direction.

[0044] The first piezoelectric element 3 is an energy generating element that generates energy for ejecting ink when a drive signal Com is applied to it. The first piezoelectric element 3 also serves as a driving element that is driven when the drive signal Com is applied to it. The first piezoelectric body 31 of the first piezoelectric element 3 contracts when a voltage is applied to it, bending the first vibration plate 131 and pressurizing the pressure chamber S1.

[0045] The first piezoelectric element 3 generally includes a second electrode 33, a first piezoelectric body 31, and a first electrode 32. The second electrode 33, the first piezoelectric body 31, and the first electrode 32 are stacked in this order from the first vibration plate 131. Therefore, the first electrode 32 is located in the Z2 direction, which is the "upward direction" of the "one side in the vertical direction" from the first piezoelectric body 31. The second electrode 33 is located in the Z1 direction, which is the "downward direction" of the "other side in the vertical direction" from the first piezoelectric body 31. By providing the first electrode 32 and the second electrode 33, pressure is efficiently applied to the first piezoelectric body 31. The second electrode 33 and the first vibration plate 131 may be in contact with each other, or another member may be interposed between the second electrode 33 and the first vibration plate 131.

[0046] Fig. 6 is a diagram showing a part of the first piezoelectric body 31 in Fig. 3. In the example of Fig. 6, the multiple first piezoelectric bodies 31 are connected to each other. Specifically, the multiple first piezoelectric bodies 31 are separated by forming multiple notches G in a strip-shaped dielectric film 310 extending along the Y2 direction. The first piezoelectric body 31 is formed of a known piezoelectric material such as lead zirconate titanate (Pb(Zr,Ti)O3).

[0047] 6, the dielectric film 310 overlaps the absorption chamber S2. However, the dielectric film 310 does not have to overlap the absorption chamber S2. The first piezoelectric bodies 31 may be formed individually without being connected to each other.

[0048] 3 is a common electrode provided in common to the multiple first piezoelectric bodies 31. The first electrode 32 is strip-shaped extending in the Y2 direction so as to be continuous across the multiple first piezoelectric elements 3. By providing the first electrode 32 in common to the multiple pressure chambers S1, it is easier to miniaturize the first piezoelectric elements 3 compared to when the first electrode 32 is provided individually. Like the second electrode 33, the first electrode 32 is formed of a low-resistance conductive material such as platinum (Pt) or iridium (Ir).

[0049] FIG. 7 is a diagram showing the second electrode 33, the first wiring portion 50, and the second wiring portion 60 in FIG. 2. As shown in FIG. 7, the second electrode 33 is elongated along the X-axis. The second electrodes 33 are spaced apart from one another and arranged along the Y-axis. The second electrodes 33 are individual electrodes formed for each first piezoelectric element 3 and spaced apart from one another. The second electrodes 33 are provided individually for the multiple pressure chambers S1. By providing the second electrodes 33 individually, even if the multiple first piezoelectric bodies 31 are formed of a single dielectric film 310, the single dielectric film 310 can be divided into multiple first piezoelectric bodies 31. The second electrode 33 is formed of a conductive material such as platinum or iridium.

[0050] The first piezoelectric element 3 is a piezoelectric element involved in the ejection of ink. A reference voltage, which is a constant voltage, is applied to the first electrode 32. The reference voltage may be, for example, a ground voltage or a voltage higher than the ground voltage. A drive signal Com is supplied to the second electrode 33. Thus, a drive voltage, the voltage of which changes with time, is applied to the second electrode 33.

[0051] A voltage corresponding to the difference between the reference voltage applied to the first electrode 32 and the drive voltage supplied to the second electrode 33 is applied to the first piezoelectric body 31. Therefore, the drive circuit 40 of FIG. 2 applies a drive voltage whose voltage changes with time to the first piezoelectric body 31. When a voltage corresponding to the difference between the reference voltage applied to the first electrode 32 and the drive voltage supplied to the second electrode 33 is applied to the first piezoelectric body 31, the first piezoelectric body 31 is deformed, and the first piezoelectric element 3 generates energy that causes the first vibration plate 131 to bend. Therefore, the first piezoelectric element 3 applies pressure to the pressure chamber S1 when the voltage is applied. The first vibration plate 131 is bent and deformed by the energy generated by the first piezoelectric element 3, so that the pressure in the pressure chamber S1 changes, and the ink in the pressure chamber S1 is ejected from the nozzle N shown in FIG. 3.

[0052] The second wiring part 60 shown in Fig. 3 is provided corresponding to the absorption chamber S2. Specifically, the second wiring part 60 is disposed on the surface of the second diaphragm 132 opposite to the absorption chamber S2. The second wiring part 60 is covered with a dielectric film 310. The second wiring part 60 is used to detect the pressure in the absorption chamber S2. The second wiring part 60 is a strain gauge. The second wiring part 60 is formed of a metal, a semiconductor, or the like.

[0053] The pressure in the absorption chamber S2 is detected by utilizing the characteristic that the electrical resistance value of metals, semiconductors, etc. changes when distortion occurs. When an external force is applied to the second wiring part 60 via the second diaphragm 132 in accordance with the pressure in the absorption chamber S2, a stress corresponding to this external force is applied to the second wiring part 60. As a result, distortion occurs in the second wiring part 60, and the resistance value changes. The pressure in the absorption chamber S2 can be detected by using this resistance value.

[0054] As described above, in the liquid ejection head 1 of this embodiment, the pressure chamber S1 and the absorption chamber S2 are provided in the pressure chamber substrate 12, and the pressure chamber S1 and the absorption chamber S2 are adjacent to each other. In this embodiment in which the pressure chamber S1 and the absorption chamber S2 are adjacent to each other, the second wiring section 60 is provided in correspondence with the second vibration plate 132. The liquid ejection head 1 is provided with a pressure acquisition section 42 that acquires the pressure of the absorption chamber S2 based on the resistance value of the second wiring section 60. For example, the pressure acquisition section 42 has a detection circuit that acquires an output voltage based on the resistance value of the second wiring section 60. The pressure acquisition section 42 detects the pressure of the absorption chamber S2 based on the correspondence relationship between the resistance value of the second wiring section 60 and the pressure stored in the storage section 23.

[0055] As described above, the absorption chamber S2 is a space that absorbs the vibration of the ink that occurs when pressure is applied to the ink in the pressure chamber S1. By providing the absorption chamber S2, the ink ejection performance can be stabilized. In this embodiment, the second wiring section 60 is provided corresponding to the second vibration plate 132 corresponding to the absorption chamber S2, and the pressure of the absorption chamber S2 can be detected based on the resistance value of the second wiring section 60. Therefore, the pressure in the vicinity of the pressure chamber S1 can be detected using the absorption chamber S2. Therefore, the pressure in the vicinity of the pressure chamber S1 can be detected with a simple configuration without forming a separate space for detecting the pressure in the vicinity of the pressure chamber S1. By being able to obtain the pressure of the absorption chamber S2 in the vicinity of the pressure chamber S1, the behavior of the ink according to the pressure of the pressure chamber S1 can be detected. Therefore, for example, it can be detected whether or not various malfunctions such as insufficient supply of ink to the multiple pressure chambers S1 and the absorption chamber S2 occur. Therefore, by being able to obtain the pressure of the absorption chamber S2 in the vicinity of the pressure chamber S1, it can contribute to improving the quality of the liquid ejection head 1.

[0056] Furthermore, unlike the pressure chamber S1, the absorption chamber S2 is not directly related to the ejection of ink. For this reason, it is always possible to detect the pressure in the absorption chamber S2 based on the resistance value of the second wiring portion 60, regardless of the ejection of ink.

[0057] In addition, the second wiring part 60 is provided at a position overlapping with the absorption chamber S2 in a plan view. Therefore, the resistance value of the second wiring part 60 is easily affected by pressure changes in the absorption chamber S2. By providing the second wiring part 60 at a position overlapping with the absorption chamber S2, the pressure in the absorption chamber S2 can be detected with higher accuracy than when the second wiring part 60 does not overlap.

[0058] 7, the second wiring part 60 includes a first bellows part 61 and a first straight part 62. The first bellows part 61 has a second bellows shape that extends along the X2 direction and is folded back sequentially toward the Y2 direction. The first straight part 62 has a straight shape that extends along the Y2 direction.

[0059] The first bellows portion 61 includes a plurality of first portions 611 and a plurality of second portions 612. The plurality of first portions 611 are portions extending in the X2 direction, spaced apart from each other, and arranged in the Y2 direction. The plurality of second portions 612 are portions extending in the Y2 direction. Each second portion 612 is disposed between two adjacent first portions 611 and connects the two adjacent first portions 611. The plurality of second portions 612 are disposed alternately at the ends of the first portions 611 in the X1 direction and the ends of the first portions 611 in the X2 direction. The second portion 612 located furthest in the Y1 direction among the plurality of second portions 612 is counted in the Y2 direction, with the second portion 612 located furthest in the Y1 direction being the first portion. In this case, for example, the odd-numbered second portions 612 among the plurality of second portions 612 are connected to the ends of the first portions 611 in the X1 direction. The even-numbered second portions 612 among the multiple second portions 612 are connected to the ends of the first portions 611 in the X2 direction.

[0060] The length of one first portion 611 is longer than the length of one second portion 612. As a result, the first portion 611 bends alternately in the X1 direction and the X2 direction, while the second portion 612 shifts little by little along the Y2 direction, resulting in a shape that extends along the Y2 direction as a whole. This shape is referred to as a shape that "extends along the X2 direction and is folded back sequentially."

[0061] The first bellows portion 61 of the second wiring portion 60 is configured to have a second bellows shape that is folded back sequentially while extending along the Y1 direction. Therefore, by having the first bellows portion 61 have the second bellows shape, the distortion is more likely to change due to pressure and is more likely to appear as a change in resistance value than when the first bellows portion 61 has a bellows shape that is folded back sequentially while extending along the X1 direction. Therefore, it is possible to achieve high sensitivity.

[0062] Moreover, the first bellows portion 61 and the first straight portion 62 are connected to each other. For example, one end of the first bellows portion 61 and one end of the first straight portion 62 are connected to each other via a wiring (not shown).

[0063] FIG. 8 is a diagram showing a bridge circuit included in the pressure detection unit 6 of FIG. 2. As shown in FIG. 8, the pressure detection unit 6 includes a first resistor element 63, a second resistor element 64, and a third resistor element 65 in addition to the first wiring unit 50 described above. The first wiring unit 50, the first resistor element 63, the second resistor element 64, and the third resistor element 65 form a Wheatstone bridge circuit. One of the other end of the first bellows portion 61 and the other end of the first straight portion 62 of the first wiring unit 50 of FIG. 6 is connected to the first resistor element 63 via a wiring 505. The other end is connected to the third resistor element 65 via a wiring 506. The first resistor element 63 is connected to the second resistor element 64 via a wiring 507. The second resistor element 64 is connected to the third resistor element 65 via a wiring 508.

[0064] In this bridge circuit, a voltage E is applied to points A and B, and an output voltage e from points C and D is detected. When a change occurs in the resistance value of the first wiring part 50, a voltage difference occurs between points C and D. This voltage difference, i.e., the output voltage e, is obtained to determine the strain of the second wiring part 60. The relationship between the output voltage e, strain, and pressure is stored in advance in the storage part 23. Therefore, the pressure in the absorption chamber S2 can be determined based on the output voltage e, which is based on the resistance value.

[0065] Although not shown in Fig. 2, a power supply circuit that supplies a voltage E to points A and B is connected to the bridge circuit of the pressure detection unit 6. Also, a detection circuit that detects an output voltage e based on the resistance value of the second wiring unit 60 is connected to the bridge circuit of the pressure acquisition unit 42. The pressure acquisition unit 42 in Fig. 2 has this detection circuit.

[0066] As described above, the pressure detection unit 6 can configure a Wheatstone bridge circuit by having the first resistor element 63, the second resistor element 64, and the third resistor element 65 in addition to the second wiring unit 60. Therefore, the minute pressure in the absorption chamber S2 can be detected using the output voltage e based on the resistance value of the first wiring unit 50.

[0067] 5, the first wiring portion 50 is disposed between the plurality of second electrodes 33 and the second wiring portion 60. The first wiring portion 50 is disposed on the diaphragm 13, and is provided in the same layer as the plurality of second electrodes 33 and the second wiring portion 60. The first wiring portion 50 is covered with a dielectric film 310. The first wiring portion 50 is a resistor used to detect the temperature of the absorption chamber S2.

[0068] As shown in FIG. 7, the first wiring part 50 has a first bellows shape that extends along the Y2 direction and is folded back in sequence. The first wiring part 50 includes a plurality of third parts 51 and a plurality of fourth parts 52. The plurality of third parts 51 are parts that extend in the Y2 direction, are spaced apart from each other, and are arranged in the X2 direction. In the illustrated example, three third parts 51 are provided. The plurality of fourth parts 52 are parts that extend in the X2 direction. Each fourth part 52 is disposed between two adjacent third parts 51 and connects the two adjacent third parts 51. In the illustrated example, two fourth parts 52 are provided. One fourth part 52 extends in the X2 direction from the end in the Y2 direction of the third part 51 that is located in the center of the three third parts 51. The other fourth part 52 extends in the X1 direction from the end in the Y1 direction of the third part 51 that is located in the center of the three third parts 51.

[0069] The length of one third portion 51 is longer than the length of one fourth portion 52. As a result, the third portion 51 bends alternately in the Y1 direction and the Y2 direction, while the fourth portion 52 shifts the shape in the X2 direction little by little, resulting in a shape that extends along the Y2 direction as a whole. This shape is referred to as a shape that "extends along the Y2 direction and is folded back sequentially."

[0070] In this way, the first wiring portion 50 is configured to have a first bellows shape that extends along the Y2 direction and is folded back sequentially. Therefore, the first wiring portion 50 can be arranged thin and long in a narrow region, for example, the region between the pressure chamber S1 and the absorption chamber S2 in a plan view. This makes it possible to increase the resistance of the first wiring portion 50. As a result, temperature changes can be detected with high sensitivity.

[0071] FIG. 9 is a diagram showing a part of the temperature detection unit 5. As shown in FIG. 9, the temperature detection unit 5 includes a first input terminal 501, a second input terminal 502, a first output terminal 503, and a second output terminal 504 in addition to the first wiring unit 50 described above. For example, a power supply circuit that applies a predetermined voltage to the second wiring unit 60 is connected to the first input terminal 501 and the second input terminal 502. The first input terminal 501 is connected to one end of the first wiring unit 50 via a wiring 505, and the second input terminal 502 is connected to the other end of the first wiring unit 50 via a wiring 506. The first output terminal 503 and the second output terminal 504 are terminals that extract an output voltage based on the resistance value of the first wiring unit 50, and are connected to a detection circuit (not shown) included in the temperature acquisition unit 41 in FIG. 2.

[0072] When a temperature change occurs in the first wiring part 50 shown in Fig. 5, an external force is applied via the second diaphragm 132 according to the pressure in the absorption chamber S2. Stress according to this external force is applied to the second wiring part 60. As a result, distortion occurs in the second wiring part 60, and the resistance value changes. The pressure in the absorption chamber S2 can be detected by using this resistance value. The first wiring part 50 is made of metal, semiconductor, or the like.

[0073] The temperature of the absorption chamber S2 is detected by utilizing the characteristic that the electrical resistance value of metals, semiconductors, etc. changes with temperature. The temperature acquisition unit 41 in FIG. 2 acquires the temperature of the absorption chamber S2 based on the resistance value of the first wiring unit 50. For example, the temperature acquisition unit 41 has a detection circuit that acquires a signal based on the resistance value of the first wiring unit 50. The temperature acquisition unit 41 detects the temperature of the absorption chamber S2 based on the correspondence between the electrical resistance value of the detection resistor 401 and the temperature. The liquid ejection head 1 has the first wiring unit 50 and the temperature acquisition unit 41, so that the temperature of a desired location such as the absorption chamber S2 can be detected.

[0074] In addition, the first wiring portion 50 is provided at a position that does not correspond to the absorption chamber S2. Therefore, the first wiring portion 50 is not subjected to a resistance change due to the pressure in the absorption chamber S2, but is subjected to only a resistance change due to the temperature of the absorption chamber S2. Therefore, by using the first wiring portion 50, it is possible to obtain a resistance value based only on the temperature of the absorption chamber S2 with high accuracy.

[0075] Furthermore, the first wiring part 50 is provided at a position that does not overlap with the pressure chamber S1 and the absorption chamber S2 in a plan view. Therefore, the resistance value of the first wiring part 50 is less affected by the vibration of the first diaphragm 131 and the second diaphragm 132. Since the first wiring part 50 is provided at a position that does not overlap with the pressure chamber S1 and the absorption chamber S2, it is less affected by the pressures in the pressure chamber S1 and the absorption chamber S2. Therefore, the temperature in the vicinity of the absorption chamber S2 can be measured with high accuracy based on the resistance value of the first wiring part 50.

[0076] In particular, the first wiring portion 50 is provided at a position between the pressure chamber S1 and the absorption chamber S2 in the X2 direction in a plan view. This allows the first wiring portion 50 to be provided in the vicinity of the absorption chamber S2. This makes it possible to detect the temperature of the absorption chamber S2 with high accuracy.

[0077] The pressure acquisition unit 42 acquires the pressure in the absorption chamber S2 based on the resistance value of the second wiring unit 60 and the temperature acquired by the temperature acquisition unit 41. The second wiring unit 60 is provided in correspondence with the absorption chamber S2, and is subject to resistance changes due to the pressure in the absorption chamber S2 and the temperature in the vicinity of the absorption chamber S2. In contrast, the first wiring unit 50 is provided in a position not corresponding to the absorption chamber S2, and is not subject to resistance changes due to the pressure in the absorption chamber S2, but is subject to only resistance changes due to the temperature in the vicinity of the absorption chamber S2. Therefore, by taking the difference between the resistance value of the second wiring unit 60 and the resistance value of the first wiring unit 50, it is possible to detect only the pressure in the absorption chamber S2 without being affected by temperature. Therefore, it is possible to measure the pressure in the absorption chamber S2 with high accuracy. In this way, by using the resistance value of the second wiring unit 60, it is possible to cancel the effect of temperature changes in the detection of the absorption chamber S2. Therefore, it is possible to improve the accuracy of pressure detection.

[0078] It was difficult to clearly distinguish between the resistance change caused by strain due to pressure change in the absorption chamber S2 and the resistance change caused by strain due to temperature change. The rate of change when the resistance value R of the second wiring portion 60 changes to R+ΔR is expressed by equation [1]. ΔR / R=kΔε+αΔT …[1] In equation [1], k is the gauge factor. Δε is the strain change. α is the temperature coefficient of resistance. ΔT is the temperature change.

[0079] As can be seen from formula [1], the resistance value R of the second wiring part 60 is caused by the strain change Δε caused by pressure and the temperature change ΔT. Therefore, in order to detect the strain caused by pressure with high accuracy, it is preferable to reduce the effect of temperature change. In order to reduce the effect of temperature change, a material with a large gauge factor k and a small resistance temperature coefficient α is selected. One example of such a material is NiCr (nickel chromium).

[0080] However, even if a material with a large gauge factor k and a small temperature coefficient of resistance α, such as NiCr, is used, the effect of temperature change remains. Also, for example, when Pt (platinum), which is a material with a large gauge factor k and easy to form the second wiring portion 60, is used, the effect of temperature change cannot be ignored.

[0081] In this embodiment, as described above, the second wiring portion 60 and the first wiring portion 50 are provided. The second wiring portion 60 is provided corresponding to the absorption chamber S2, and the resistance change of the second wiring portion 60 is expressed by the above formula [1]. On the other hand, the first wiring portion 50 is provided at a position not corresponding to the absorption chamber S2. Therefore, the resistance change of the first wiring portion 50 is expressed by the following formula [2] in which Δε=0 is assumed in the above formula [1]. ΔR / R=αΔT …[2]

[0082] The second wiring portion 60 is used to measure the resistance change due to temperature and pressure, and the first wiring portion 50 is used to measure the resistance change due to temperature alone. Then, by subtracting the resistance change of the first wiring portion 50 from the resistance change of the second wiring portion 60, the resistance change due to pressure alone can be obtained.

[0083] In this way, by using the second wiring section 60 and the first wiring section 50, it is possible to clearly distinguish between resistance changes caused by strain due to pressure changes in the absorption chamber S2 and resistance changes caused by strain due to temperature changes. In addition, it is possible to cancel the effect of temperature changes in pressure detection. Therefore, it is possible to improve the detection accuracy of the pressure in the absorption chamber S2.

[0084] In addition, the first wiring section 50 and the second wiring section 60 may be formed of different materials, but are preferably formed of the same material. By using the same material, the difference in temperature and pressure characteristics due to the difference in material can be reduced. Therefore, the detection accuracy of pressure can be improved. In other words, the accuracy of pressure calculation can be improved.

[0085] A conductive material is used as the material of each of the first wiring section 50 and the second wiring section 60. Specifically, for example, a conductive metal oxide such as ITO (indium tin oxide), a metal such as Pt, Ir (iridium), Au (gold), Ti (titanium), an alloy such as NiCr, etc. are used. In addition, the first wiring section 50 and the second wiring section 60 may be a single layer or multiple layers.

[0086] Moreover, the first wiring portion 50 and the second wiring portion 60 are preferably formed from the same material as the second electrode 33 of the first piezoelectric body 31. By forming them from the same material, the second electrode 33, the first wiring portion 50, and the second wiring portion 60 can be formed in the same process, which is convenient. Note that each of the first wiring portion 50 and the second wiring portion 60 may be formed from a material different from that of the second electrode 33.

[0087] 5, the first piezoelectric body 31 and the first electrode 32 are disposed on the first wiring portion 50 and the second wiring portion 60. Therefore, the first wiring portion 50 and the second wiring portion 60 are less susceptible to the effects of humidity compared to a case in which they are not disposed on the first wiring portion 50 and the second wiring portion 60. This can improve the accuracy of pressure detection.

[0088] As described above, the pressure chamber substrate 12 is provided with at least a plurality of pressure chambers S1 and one absorption chamber S2 commonly connected to the plurality of pressure chambers S1. Since the volume of the absorption chamber S2 is larger than the volume of each pressure chamber S1, the plane area of ​​the second vibration plate 132 forming the absorption chamber S2 can be made larger than the plane area of ​​each first vibration plate 131 forming each pressure chamber S1. Therefore, the displacement of the second vibration plate 132 can be made larger than the displacement of the first vibration plate 131. Therefore, the absorption efficiency of the absorption chamber S2 can be improved. Furthermore, by detecting the pressure of one absorption chamber S2 commonly connected to the plurality of pressure chambers S1, the pressure of the absorption chamber S2 due to the influence of the plurality of pressure chambers S1 can be detected, instead of the pressure of each pressure chamber S1. Therefore, the pressure can be used to detect malfunctions such as whether or not various malfunctions such as a shortage of ink supply have occurred.

[0089] According to the present embodiment described above, the pressure in the vicinity of the pressure chamber S1 can be obtained by utilizing the absorption chamber S2, which is a space that absorbs vibrations of the ink.

[0090] 2. Second embodiment A second embodiment will be described. In the following exemplary embodiment, for elements having the same actions and functions as those in the first embodiment, the reference numerals used in the description of the first embodiment will be used and detailed descriptions of each will be omitted as appropriate.

[0091] Fig. 10 is a plan view showing a first wiring portion 50A of the second embodiment. The first wiring portion 50A in Fig. 10 includes a second bellows portion 53 and a second straight portion 54. The second bellows portion 53 has a third bellows shape that extends along the X2 direction and is folded back sequentially toward the Y2 direction. The second straight portion 54 has a straight shape that extends along the Y2 direction.

[0092] The second bellows portion 53 includes a plurality of fifth portions 531 and a plurality of sixth portions 532. The plurality of fifth portions 531 are portions extending in the X2 direction, spaced apart from each other, and arranged in the Y2 direction. The plurality of sixth portions 532 are portions extending in the Y2 direction. Each sixth portion 532 is disposed between two adjacent fifth portions 531 and connects the two adjacent fifth portions 531. The plurality of sixth portions 532 are disposed alternately at the ends of the fifth portions 531 in the X1 direction and the ends of the fifth portions 531 in the X2 direction. The sixth portion 532 located furthest in the Y1 direction among the plurality of sixth portions 532 is counted in the Y2 direction, with the sixth portion 532 located furthest in the Y1 direction being the first. In this case, for example, the odd-numbered sixth portions 532 among the plurality of sixth portions 532 are connected to the ends of the fifth portions 531 in the X1 direction. Among the plurality of sixth portions 532, the even-numbered sixth portions 532 are connected to the ends of the fifth portions 531 in the X2 direction.

[0093] The second bellows portion 53 of the first wiring portion 50A is configured to have a third bellows shape that extends along the X2 direction and is folded back sequentially toward the Y1 direction. Therefore, since the second bellows portion 53 has the third bellows shape, the first wiring portion 50A can be arranged to be thin and long. Therefore, the resistance of the first wiring portion 50A can be increased.

[0094] In addition, the third bellows shape of the second bellows portion 53 of the first wiring portion 50A has a shorter length of the portion extending along the X2 direction than the second bellows shape of the first bellows portion 61 of the second wiring portion 60. That is, the length of the fifth portion 531 in the X2 direction is shorter than the length of the first portion 611 in the X2 direction. Therefore, the initial values ​​of the resistance are different between the first wiring portion 50A and the second wiring portion 60. Even if the initial values ​​of the resistance are different, the rate of change ΔR / R is common between the first wiring portion 50A and the second wiring portion 60. Therefore, only the resistance change due to pressure can be detected by subtracting the relationship between the above-mentioned formulas [1] and [2].

[0095] The second wiring portion 60 is used to obtain a resistance value from a change in distortion based on the vibration of the second diaphragm 132 and detect the pressure in the absorption chamber S2. For this reason, it is preferable that the second wiring portion 60 is disposed in a wide area. On the other hand, if the first wiring portion 50A is formed in the same shape as the second wiring portion 60, the plane area of ​​the diaphragm 13 may become large. Therefore, it is preferable that the plane area of ​​the first wiring portion 50A is smaller than the plane area of ​​the second wiring portion 60. From this viewpoint, as in this embodiment, it is preferable that the length in the X2 direction of the fifth portion 531 is shorter than the length in the X2 direction of the first portion 611.

[0096] 3. Third embodiment A third embodiment will be described. In the following exemplary embodiment, for elements having the same actions and functions as those in the first embodiment, the reference numerals used in the description of the first embodiment will be used and detailed descriptions of each will be omitted as appropriate.

[0097] Fig. 11 is a plan view showing a first wiring portion 50B of the third embodiment. The first wiring portion 50B in Fig. 11 includes a third bellows portion 55 and a third straight portion 56. The third bellows portion 55 has a third bellows shape that extends along the X2 direction and is folded back sequentially toward the Y2 direction. The third straight portion 56 has a straight shape that extends along the Y2 direction.

[0098] The third bellows portion 55 includes a plurality of seventh portions 551 and a plurality of eighth portions 552. The plurality of seventh portions 551 are portions extending in the X2 direction, spaced apart from each other, and arranged in the Y2 direction. The plurality of eighth portions 552 are portions extending in the Y2 direction. Each of the eighth portions 552 is disposed between two adjacent seventh portions 551 and connects the two adjacent seventh portions 551. The plurality of eighth portions 552 are disposed alternately at the ends of the seventh portions 551 in the X1 direction and the ends of the seventh portions 551 in the X2 direction. The eighth portion 552 located furthest in the Y1 direction among the plurality of eighth portions 552 is counted in the Y2 direction, with the eighth portion 552 located furthest in the Y1 direction being the first. In this case, for example, the odd-numbered eighth portions 552 among the plurality of eighth portions 552 are connected to the ends of the seventh portions 551 in the X1 direction. Among the multiple eighth portions 552, the even-numbered eighth portions 552 are connected to the ends of the seventh portions 551 in the X2 direction.

[0099] The third bellows portion 55 of the first wiring portion 50B is configured to have a fourth bellows shape that extends along the X2 direction and is folded back sequentially toward the Y1 direction. Therefore, since the third bellows portion 55 has the fourth bellows shape, the first wiring portion 50B can be arranged to be thin and long. Therefore, the resistance of the first wiring portion 50B can be increased.

[0100] The fourth bellows shape of the third bellows portion 55 is the same as the first bellows shape of the first bellows portion 61 of the second wiring portion 60. Therefore, the third bellows portion 55 of the first wiring portion 50B is configured to have a fourth bellows shape in which the length of the portion extending along the X2 direction of the third bellows portion 55 is the same as the length of the portion extending along the X2 direction of the first bellows shape of the first bellows portion 61. In other words, the length in the X2 direction of the seventh portion 551 is the same as the length in the X2 direction of the first portion 611.

[0101] Since the fourth bellows shape of the third bellows portion 55 and the first bellows shape of the first bellows portion 61 are the same, when no pressure is applied to the first wiring portion 50B and the second wiring portion 60 and the temperature is in equilibrium, the initial resistance values ​​of the first wiring portion 50B and the second wiring portion 60 are the same. Therefore, the pressure change in the absorption chamber S2 can be detected by simply subtracting the resistance value of the first wiring portion 50B from the resistance value of the second wiring portion 60.

[0102] 4. Variations The above-described embodiment may be modified in various ways. Specific modified aspects that may be applied to the above-described embodiment are illustrated below. Two or more aspects selected from the following examples may be combined as appropriate to the extent that they are not mutually contradictory.

[0103] 12 is a block diagram of a liquid ejection device 100a according to a modified example. The liquid ejection device 100a includes a liquid ejection head 1a and a control unit 20a. A drive circuit 40, a temperature acquisition unit 41, and a pressure acquisition unit 42 are provided in the control unit 20a. The liquid ejection head 1a is not provided with the temperature acquisition unit 41 or the pressure acquisition unit 42.

[0104] 12, the drive circuit 40, the temperature acquisition unit 41, and the pressure acquisition unit 42 may be provided in part or in whole in the control unit 20. With this liquid ejection device 100a, as in each of the embodiments, the pressure in the vicinity of the pressure chamber S1 can be acquired by utilizing the absorption chamber S2, which is a space that absorbs vibrations of the ink.

[0105] The shape of each of the "second wiring portion" and the "first wiring portion" is preferably a shape that is easily subjected to stress due to deformation of first diaphragm 131 or second diaphragm 132, and is not limited to a bellows shape.

[0106] Furthermore, the "liquid ejection head" may be a circulation type head having a so-called circulation flow path.

[0107] Fig. 13 is a cross-sectional view of a portion of a modified liquid ejection head 10. The liquid ejection head 10 shown in Fig. 13 has a nozzle substrate 11, a pressure chamber substrate 120, a vibration plate 130, a sealing substrate 140, a case 150, a wiring substrate 49, a first piezoelectric element 3, a pressure detection unit 6, a temperature detection unit 5, and a second piezoelectric element 7. The liquid ejection head 10 in Fig. 13 is a circulation type head having a so-called circulation flow path.

[0108] The pressure chamber substrate 120 is a laminate of a third substrate 124 and a fourth substrate 125. These substrates are manufactured by processing a semiconductor substrate such as a silicon single crystal substrate. In addition to a plurality of pressure chambers S1, an absorption chamber S2, a plurality of first communication channels R1 and a second communication channel R2, a plurality of fourth communication channels R4, a plurality of fifth communication channels R5, a sixth communication channel R6, and a discharge-side absorption chamber S3 are formed in the pressure chamber substrate 120. The absorption chamber S2 is a supply-side absorption chamber.

[0109] One first communication channel R1 communicates with one fifth communication channel R5 via one fourth communication channel R4. Each fourth communication channel R4 overlaps with a nozzle N in a plan view. Each fifth communication channel R5 communicates with a discharge-side absorption chamber S3. The discharge-side absorption chamber S3 overlaps with the second piezoelectric element 7 in a plan view. The discharge-side absorption chambers S3 communicate with a sixth communication channel R6.

[0110] The diaphragm 130 includes a third diaphragm 133 in addition to a plurality of first diaphragms 131 and second diaphragms 132. The third diaphragm 133 is a portion of the diaphragm 130 that overlaps with the discharge-side absorption chamber S3 in a plan view.

[0111] The case 150 is in contact with the sealing substrate 140. The case 150 and the sealing substrate 140 may be integrated. A third communication flow path R3 and a seventh communication flow path R7 are formed in the case 150. The seventh communication flow path R7 and the sixth communication flow path R6 form a common ink chamber R0.

[0112] In addition to the first space H1 and the wiring space H0, a second space H3 is formed in the sealing substrate 140. A second piezoelectric element 7 is disposed in the second space H3. The second piezoelectric element 7 is disposed on the surface of the third diaphragm 133 opposite to the discharge-side absorption chamber S3. The second piezoelectric element 7 is used to detect the pressure in the discharge-side absorption chamber S3. The second piezoelectric element 7 deforms in response to the third diaphragm 133, which bends in response to the pressure in the discharge-side absorption chamber S3.

[0113] The second piezoelectric element 7 has a third electrode 72, a second piezoelectric body 71, and a fourth electrode 73. These are elongated along the Y axis. The fourth electrode 73, the second piezoelectric body 71, and the third electrode 72 are laminated in this order from the third vibration plate 133. The second piezoelectric body 71 is made of a known piezoelectric material such as lead zirconate titanate. The third electrode 72 and the fourth electrode 73 are each made of a conductive material such as platinum or iridium. The second piezoelectric element 7 does not apply pressure to the liquid in the flow path, but serves to absorb vibrations.

[0114] The third diaphragm 133, the second piezoelectric element 7, and the discharge-side absorption chamber S3 are elongated along the Y-axis and are provided for the multiple pressure chambers S1, but may be provided for each pressure chamber S1. Therefore, multiple third diaphragms 133, second piezoelectric elements 7, and discharge-side absorption chambers S3 may be provided.

[0115] In this liquid ejection head 10, ink flows through the common ink chamber R and the absorption chamber S2 into the pressure chamber S1. When the first piezoelectric element 3 is driven, the pressure in the pressure chamber S1 fluctuates, and this pressure fluctuation causes the ink to be ejected as ink droplets from the nozzle N through the first communication channel R1 and the fourth communication channel R4. At the same time, the ink flows back through the fifth communication channel R5, the discharge side absorption chamber S3, and the common ink chamber R0. In this manner, the ink circulates.

[0116] Furthermore, in the liquid ejection head 10, an absorption chamber S2 is provided in the X2 direction relative to the pressure chamber S1, and a discharge-side absorption chamber S3 is provided in the X1 direction relative to the pressure chamber S1. In other words, vibration absorbing mechanisms are provided on the ink supply side and discharge side relative to the pressure chamber S1. Furthermore, the distance between the absorption chamber S2 and the pressure chamber S1 is shorter than the distance between the discharge-side absorption chamber S3 and the pressure chamber S1. A pressure detection unit 6 is provided for the absorption chamber S2, which is closer to the pressure chamber S1. Therefore, by detecting the pressure in the vicinity of the pressure chamber S1 using the absorption chamber S2, which is closer to the pressure chamber S1, the behavior of the ink according to the pressure of the pressure chamber S1 can be detected with greater accuracy.

[0117] The "liquid ejection device" can be used in various devices such as facsimile machines and copy machines, as well as devices dedicated to printing. The uses of the liquid ejection device are not limited to printing. For example, a liquid ejection device that ejects a solution of a color material is used as a manufacturing device for forming a color filter of a display device such as a liquid crystal display panel. A liquid ejection device that ejects a solution of a conductive material is used as a manufacturing device for forming wiring and electrodes of a wiring board. A liquid ejection device that ejects a solution of an organic substance related to a living body is used as a manufacturing device for manufacturing a biochip, for example.

[0118] Although the present invention has been described based on the preferred embodiment, the present invention is not limited to the above embodiment. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that exhibits the same function as the above embodiment, and any configuration can be added. [Explanation of symbols]

[0119] 1...liquid ejection head, 1a...liquid ejection head, 3...first piezoelectric element, 5...temperature detection section, 6...pressure detection section, 9...liquid container, 11...nozzle substrate, 12...pressure chamber substrate, 13...diaphragm, 14...sealing substrate, 20...control unit, 20a...control unit, 21...control section, 22...medium transport mechanism, 23...storage section, 24...movement mechanism, 25...driving signal generation circuit, 31...first piezoelectric body, 3 2...first electrode, 33...second electrode, 40...drive circuit, 41...temperature acquisition section, 42...pressure acquisition section, 49...wiring board, 50...first wiring section, 50A...first wiring section, 50B...first wiring section, 51...third section, 52...fourth section, 53...second bellows section, 54...second straight section, 55...third bellows section, 56...third straight section, 60...second wiring section, 61...first bellows section, 62...first straight section, 63...second 1 resistance element, 64... second resistance element, 65... third resistance element, 90... medium, 100... liquid ejection device, 100a... liquid ejection device, 121... first substrate, 122... second substrate, 131... first diaphragm, 132... second diaphragm, 141... filter, 242... conveyor, 244... conveyor belt, 310... dielectric film, 401... detection resistor, 501... first input terminal, 502... second input terminal, 503...first output terminal, 504...second output terminal, 505...wiring, 506...wiring, 507...wiring, 508...wiring, 531...fifth part, 532...sixth part, 551...seventh part, 552...eighth part, 611...first part, 612...second part, G...notch, H0...space for wiring, H1...first space, N...nozzle, R0...common ink chamber, R1...first communicating flow path, R2...second communicating flow path.

Claims

1. a nozzle substrate provided with nozzles for ejecting liquid; a pressure chamber substrate having a pressure chamber in which pressure is applied to liquid for ejecting the liquid from the nozzle, and an absorption chamber adjacent to the pressure chamber in a second direction and absorbing vibrations of the liquid generated when pressure is applied to the liquid in the pressure chamber; a first diaphragm provided in correspondence with the pressure chamber and vibrating to apply pressure to the liquid; a second vibration plate provided in correspondence with the absorption chamber and vibrating to absorb the pressure of the liquid; A second wiring portion provided at a position corresponding to the absorption chamber; a pressure acquisition section that acquires a pressure in the absorption chamber based on a resistance value of the second wiring section.

2. 2. The liquid ejection head according to claim 1, wherein the pressure chamber substrate is provided with at least a plurality of the pressure chambers arranged in a first direction intersecting the second direction, and one absorption chamber commonly connected to the plurality of pressure chambers.

3. 3. The liquid ejection head according to claim 2, wherein the second wiring portion is configured to have a second bellows shape that is folded back successively while extending in the second direction.

4. A first wiring portion provided at a position not corresponding to the absorption chamber; The liquid ejection head according to claim 2 , further comprising a temperature acquisition section that acquires a temperature of the absorption chamber based on a resistance value of the first wiring section.

5. The liquid ejection head according to claim 4 , wherein the pressure acquisition section acquires the pressure in the absorption chamber based on a resistance value of the second wiring section and the temperature acquired by the temperature acquisition section.

6. When viewed from a top-bottom direction intersecting the first direction and the second direction, The second wiring portion is provided at a position overlapping with the absorption chamber, 5. The liquid ejection head according to claim 4, wherein the first wiring portion is provided at a position that does not overlap with the pressure chamber and the absorption chamber.

7. When viewed from the top and bottom direction, 7. The liquid ejection head according to claim 6, wherein the first wiring portion is provided at a position between the pressure chamber and the absorption chamber in the second direction.

8. 5. The liquid ejection head according to claim 4, wherein the first wiring portion is configured to have a first bellows shape that is folded back successively while extending along the first direction.

9. the second wiring portion is configured to have a second bellows shape that extends along the second direction and is folded back sequentially, The liquid ejection head according to claim 4, characterized in that the first wiring portion is configured to have a third bellows shape that extends along the second direction and then folds back sequentially, and the length of the portion extending along the second direction of the third bellows shape is shorter than that of the second bellows shape.

10. the second wiring portion is configured to have a second bellows shape that extends along the second direction and is folded back sequentially, The liquid ejection head according to claim 4, characterized in that the first wiring portion has a fourth bellows shape that extends along the second direction and then folds back sequentially, and is configured to have the fourth bellows shape having the same length as the second bellows shape in the portion extending along the second direction.

11. 2. The liquid ejection head according to claim 1, wherein the first diaphragm and the second diaphragm are not separate but are formed of a continuous member.

12. 5. The liquid ejection head according to claim 4, wherein the first wiring portion and the second wiring portion are formed from the same material.

13. a first piezoelectric body provided at a position corresponding to the pressure chamber and above the first vibration plate; A first electrode provided on an upper side of the first piezoelectric body; A second electrode provided on the lower side of the first piezoelectric body, 5. The liquid ejection head according to claim 4, wherein the first wiring portion and the second wiring portion are formed from the same material as the second electrode.

14. a nozzle substrate provided with nozzles for ejecting liquid; a pressure chamber substrate having a pressure chamber in which pressure is applied to liquid for ejecting the liquid from the nozzle, and an absorption chamber adjacent to the pressure chamber in a second direction and absorbing vibrations of the liquid generated when pressure is applied to the liquid in the pressure chamber; a first diaphragm provided in correspondence with the pressure chamber and vibrating to apply pressure to the liquid; a second vibration plate provided in correspondence with the absorption chamber and vibrating to absorb the pressure of the liquid; a liquid ejection head including a second wiring portion provided at a position corresponding to the absorption chamber; a pressure acquisition section that acquires a pressure in the absorption chamber based on a resistance value of the second wiring section.

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