Liquid discharge device

Abstract

To simultaneously perform driving of a discharge section and detection of a change in a pressure of liquid in the discharge section.SOLUTION: A liquid discharge device includes: a flow passage substrate which has one or more pressure chambers, an absorption chamber absorbing vibration of liquid propagated from the pressure chambers, and a nozzle connected to the pressure chambers so as to discharge liquid; a diaphragm laminated on the flow passage substrate; a first piezoelectric element which is provided at a position overlapping the pressure chambers viewed from a lamination direction with respect to a first surface to be a surface on an opposite side of a side where the pressure chambers exist of the diaphragm and the first piezoelectric element which vibrates the diaphragm and applies a pressure to liquid in the pressure chambers; a second piezoelectric element which is provided at a position overlapping the absorption chamber with respect to the first surface of the diaphragm and the second piezoelectric element which absorbs at least a part of vibration of liquid propagated from the pressure chamber due to deformation; and a pressure detection section which detects the pressure of liquid in the absorption chamber on the basis of electromotive force of the second piezoelectric element.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection device. [Background technology]

[0002] Patent Document 1 describes technology related to a liquid ejection device. In this liquid ejection device, when a drive signal generation unit outputs a drive signal for ejecting ink, a piezoelectric element provided in the ejection unit is driven. The piezoelectric element is bonded to a vibration plate that closes the upper opening of the cavity plate. When the vibration plate is vibrated by driving the piezoelectric element, ink is ejected from a nozzle communicating with the cavity. In this liquid ejection device, an ejection abnormality detection unit detects changes in the pressure of the liquid inside the ejection unit based on a residual vibration signal generated after the piezoelectric element is driven. The residual drive signal is a signal that indicates changes in the electromotive force of the piezoelectric element.

[0003] Furthermore, in the technology described in Patent Document 1, in order to switch between driving for ink ejection and detecting abnormalities, a switching unit switches between a state in which the ejection unit is connected to a drive vibration generating unit and a state in which the ejection unit is connected to an ejection abnormality detection unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-147363 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the technology described in Patent Document 1, it is not possible to simultaneously drive the ejection portion to eject ink and detect changes in the pressure of the liquid inside the ejection portion. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a liquid ejection device comprising: a flow path substrate having one or more pressure chambers forming a liquid flow path, at least one absorption chamber connected to the pressure chambers, forming a liquid flow path together with the pressure chambers and absorbing vibrations of the liquid propagated from the pressure chambers, and a nozzle connected to the pressure chambers and ejecting the liquid; a vibration plate stacked on the flow path substrate at a position overlapping with the pressure chambers and the absorption chambers in a stacking direction; a first piezoelectric element provided on a first surface of the vibration plate, which is the surface opposite to the side where the pressure chambers are present, at a position overlapping with the pressure chambers in the stacking direction, the first piezoelectric element vibrating the vibration plate to apply pressure to the liquid in the pressure chambers; a second piezoelectric element provided on the first surface of the vibration plate at a position overlapping with the absorption chambers in the stacking direction, the second piezoelectric element deforming to absorb at least a portion of the vibrations of the liquid propagated from the pressure chambers; and a pressure detection unit that detects the pressure of the liquid in the absorption chambers based on the electromotive force of the second piezoelectric element. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating a general configuration of a liquid ejection device. [Figure 2] FIG. 2 is an exploded perspective view showing the configuration of the liquid ejection head. [Figure 3] 3 is a cross-sectional view of the liquid ejection head taken along the line III-III in FIG. 2. FIG. [Figure 4] 4 is a cross-sectional view of the pressure chamber and the absorption chamber taken along line IV-IV in FIG. 3. FIG. [Figure 5] FIG. 4 is an enlarged view of a vibrating part in FIG. 3. [Figure 6] FIG. 10 is a diagram showing an example of the arrangement of piezoelectric bodies. [Figure 7] FIG. 11 is an enlarged view of a vibrating part according to a third embodiment. [Figure 8] FIG. 10 is a schematic diagram showing the arrangement of an absorbing part according to a fourth embodiment. [Figure 9] 10A and 10B are diagrams illustrating examples of the arrangement of drive wiring and detection wiring. DETAILED DESCRIPTION OF THE INVENTION

[0008] A1. Embodiment 1: FIG. 1 is a schematic diagram showing the general configuration of a liquid ejection device 300 equipped with a liquid ejection head 100. For ease of understanding, an XYZ Cartesian coordinate system is set in FIG. 1. The X and Y axes are assumed to be along a horizontal plane, and the Z axis is assumed to be along a vertical line. Therefore, the -Z axis direction is the direction of gravity. However, this may not be the case depending on the orientation of the liquid ejection device 300. In this specification, orthogonal includes a range of 90°±10°.

[0009] The liquid ejection device 300 is an inkjet printer that prints an image on a medium, namely, printing paper P, by ejecting ink as a liquid. Specifically, the liquid ejection device 300 ejects ink onto the printing paper P based on print data that indicates the on / off status of dots on the printing paper P, forming dots at various positions on the printing paper P. The liquid ejection device 300 may eject liquid onto media other than printing paper P, such as plastic, film, fiber, fabric, leather, metal, glass, wood, and ceramics. The liquid ejection device 300 may eject various color materials, electrode materials, biological organic materials, inorganic samples, lubricating oils, resin liquids, etching liquids, and the like, instead of ink.

[0010] The liquid ejection device 300 includes a liquid ejection head 100 , a liquid container 310 , a head moving mechanism 320 , a transport mechanism 330 , and a control unit 500 .

[0011] The liquid ejection head 100 has a plurality of nozzles 21 that eject liquid. The liquid ejection head 100 is mounted on a carriage 322 and moves back and forth mainly in the main scanning direction as the carriage 322 moves. While moving back and forth in the main scanning direction, the liquid ejection head 100 ejects liquid supplied from a liquid container 310 onto the printing paper P that is transported in the sub-scanning direction. In the first embodiment, the main scanning direction is the +Y direction and the -Y direction. The sub-scanning direction is a direction that intersects the main scanning direction and is the +X direction and the -X direction. In the example shown, the liquid is ejected from the nozzles 21 in the -Z direction.

[0012] The liquid container 310 stores the liquid to be ejected from the liquid ejection head 100. The liquid stored in the liquid container 310 is supplied to the liquid ejection head 100 via a resin tube 312. The liquid container 310 may be a bag-shaped liquid pack made of a flexible film, a cartridge that is detachable from the liquid ejection device 300, an ink tank, or the like.

[0013] The head movement mechanism 320 includes a drive belt 321, a carriage 322, a movement motor 326, and a pulley 327. The carriage 322 mounts the liquid ejection head 100 in a state where it is capable of ejecting liquid. The carriage 322 is fixed to the drive belt 321. The drive belt 321 is stretched between the movement motor 326 and the pulley 327. When the movement motor 326 is driven to rotate, the drive belt 321 moves back and forth in the main scanning direction. As a result, the carriage 322 fixed to the drive belt 321 also moves back and forth in the main scanning direction.

[0014] The transport mechanism 330 transports the printing paper P in the sub-scanning direction. The transport mechanism 330 includes three transport rollers 332, a transport rod 334 to which the transport rollers 332 are attached, and a transport motor 336 that rotates the transport rod 334. The transport motor 336 rotates the transport rod 334, thereby transporting the printing paper P in the sub-scanning direction.

[0015] The control unit 500 controls the entire liquid ejection device 300. The functions of the control unit 500 are realized by a computer equipped with a processor and memory. For example, the control unit 500 controls the reciprocating movement of the carriage 322 in the main scanning direction, the transport movement of the printing paper P in the sub-scanning direction, and the ejection operation of the liquid ejection head 100.

[0016] Fig. 2 is an exploded perspective view showing the configuration of the liquid ejection head 100. Fig. 3 is a cross-sectional view of the liquid ejection head 100 taken along the line III-III in Fig. 2.

[0017] As shown in Fig. 2, the liquid ejection head 100 includes a head main body 11, a case member 40, and a wiring board 120. As shown in Fig. 3, the head main body 11 and the case member 40 are configured to be plane-symmetrical with respect to a central plane O. The central plane O is a plane parallel to the X-axis and Z-axis, and is an XZ plane equidistant from the nozzle row L1 and the nozzle row L2. The configurations of the head main body 11 and the case member 40 are the same in the +Y direction and the -Y direction with respect to the central plane O.

[0018] As shown in FIG. 2, the head main body 11 has a pressure chamber substrate 10, a communication substrate 15, a nozzle substrate 20, and a vibration section 30. The pressure chamber substrate 10, the communication substrate 15, the nozzle substrate 20, and the vibration section 30 are laminated members. These laminated members are stacked to form the liquid ejection head 100. In the first embodiment, the direction in which the laminated members that form the liquid ejection head 100 are stacked is also referred to as the stacking direction. In this embodiment, the stacking direction is the Z-axis direction.

[0019] The pressure chamber substrate 10 is fixed onto the communication substrate 15 with an adhesive or the like. The pressure chamber substrate 10 is formed of a silicon single crystal substrate. Alternatively, the pressure chamber substrate 10 may be formed of a metal such as stainless steel (SUS) or nickel (Ni), a ceramic material such as zirconia (ZrO2) or alumina (Al2O3), a glass ceramic material, or an oxide material such as magnesium oxide (MgO) or lanthanum aluminate (LaAlO3).

[0020] 3, pressure chambers 12, absorption chambers 13, and support portions 14 are formed in the pressure chamber substrate 10. The pressure chambers 12 and absorption chambers 13 together form part of a liquid flow path. The pressure chambers 12 and absorption chambers 13 are formed by processing the pressure chamber substrate 10 by anisotropic etching, for example.

[0021] The pressure chamber 12 and the absorption chamber 13 are provided at the same position in the Z-axis direction and adjacent to each other in the Y-axis direction. A support portion 14, which is formed as part of the pressure chamber substrate 10 and separates the pressure chamber 12 from the absorption chamber 13, is provided between the pressure chamber 12 and the absorption chamber 13. The pressure chamber 12 and the absorption chamber 13 are connected in the Y-axis direction via a communication passage Cm1 provided below the support portion 14.

[0022] 4 is a cross-sectional view of the pressure chamber 12 and the absorption chamber 13 taken along line IV-IV in FIG. 3. The dashed line indicates the position of the nozzle 21. The dashed-dotted line indicates the position of the actuator 150. The dashed-two-dotted line indicates the position of the absorption unit 200. The pressure chambers 12 are individually arranged along the Y-axis direction corresponding to the nozzles 21. Each pressure chamber 12 is formed as a space with its longitudinal direction in the Y-axis direction and its lateral direction in the X-axis direction. The pressure chambers 12 are connected to one absorption chamber 13. The absorption chamber 13 extends along the X-axis direction, which intersects with the direction in which the pressure chambers 12 extend. The absorption chamber 13 is formed as a space with its longitudinal direction in the X-axis direction and its lateral direction in the Y-axis direction. The longitudinal direction of the absorption chamber 13 is the same direction as the arrangement of the pressure chambers 12. The longitudinal direction of the absorption chamber 13 is also referred to as the first direction. The longitudinal direction of the pressure chamber 12 is also referred to as the second direction.

[0023] In the first embodiment, the length W1 in the X-axis direction of the actuator 150 corresponding to one pressure chamber 12 is shorter than the length W2 in the X-axis direction of the absorption member 200. For convenience of illustration, the length W2 is omitted from Fig. 4. Compared to when the length W1 is longer than the length W2 or when the lengths W1 and W2 are equal, setting the length X1 shorter than the length W2 makes it easier to ensure the flexibility of the absorption member 200. The functions of the pressure chambers 12 and the absorption chambers 13 will be described later.

[0024] As shown in Figures 2 and 3, the communicating substrate 15 is disposed between the pressure chamber substrate 10 and the nozzle substrate 20. The communicating substrate 15 is fixed onto the nozzle substrate 20 with an adhesive. The communicating substrate 15 is formed, for example, from a silicon single crystal substrate. By disposing the communicating substrate 15 between the pressure chamber substrate 10 and the nozzle substrate 20, it is easier to ensure the flatness of the nozzle substrate 20 compared to when the pressure chamber substrate 10 and the nozzle substrate 20 are directly stacked, and the quality of the liquid ejected from the nozzles 21 can be stabilized.

[0025] 3, the communication substrate 15 is formed with a first communication flow path 16, a first common liquid chamber 17, a second common liquid chamber 18, and a second communication flow path 19. The first communication flow path 16 is formed as an opening that penetrates the communication substrate 15 in the Z-axis direction. The first communication flow path 16 is a flow path that connects the pressure chambers 12 and the nozzles 21. The communication substrate 15 is formed with a number of first communication flow paths 16 that corresponds to the number of the nozzles 21.

[0026] The first common liquid chamber 17 is formed as an opening that penetrates the communicating substrate 15 in the Z-axis direction. The second common liquid chamber 18 is formed as a recessed portion provided in the lower surface of the communicating substrate 15. The first common liquid chamber 17 and the second common liquid chamber 18, together with a liquid chamber portion 42 formed in a case member 40 (described later), form a common liquid chamber portion 25. The common liquid chamber portion 25 constitutes part of the liquid flow path and stores the liquid to be supplied to the nozzle 21. The second communicating flow path 19 is formed as an opening that penetrates the communicating substrate 15 in the Z-axis direction. The second communicating flow path 19 is a flow path that connects the absorption chamber 13 and the second common liquid chamber 18.

[0027] As shown in FIG. 2, the nozzle substrate 20 is disposed on the surface of the communication substrate 15 opposite to the surface that contacts the pressure chamber substrate 10, i.e., on the -Z side of the communication substrate 15. The nozzle substrate 20 is made of, for example, a stainless steel substrate, a substrate formed from an organic material such as polyimide resin, or a silicon single crystal substrate. The nozzle substrate 20 has a plurality of nozzles 21. The plurality of nozzles 21 are holes that penetrate the nozzle substrate 20 in the Z-axis direction. The plurality of nozzles 21 are arranged along the X-axis direction. The pressure chamber substrate 10, communication substrate 15, and nozzle substrate 20 are collectively referred to as a flow path substrate.

[0028] The vibration section 30 is disposed on the surface of the pressure chamber substrate 10 opposite to the surface that contacts the communicating substrate 15, i.e., on the +Z side surface of the pressure chamber substrate 10. As shown in Fig. 3, the vibration section 30 has a protection substrate 31, an actuator 150, a vibration plate 155, and an absorbing section 200. The absorbing section 200 is also referred to as a second piezoelectric element.

[0029] The protective substrate 31 is laminated on the pressure chamber substrate 10 with the vibration plate 155 sandwiched therebetween. The material forming the protective substrate 31 is the same as that of the pressure chamber substrate 10. The protective substrate 31 is provided to protect the actuator 150 by means of a recess 33, which will be described later.

[0030] FIG. 5 is an enlarged view of the vibration section 30 in FIG. 3. As shown in FIG. 5, a recess 33, an atmosphere communication hole 38, and a through-hole 39 are formed in the protective substrate 31 of the vibration section 30. The recess 33 is a recess that opens to the -Z side. The recess 33 is not connected to a liquid flow path. Therefore, liquid does not flow through the recess 33. The atmosphere communication hole 38 is connected to the end of the recess 33 in the X-axis direction. The recess 33 is connected to the outside via the atmosphere communication hole 38. In this way, the pressure in the recess 33 is maintained at atmospheric pressure with a simple configuration. As shown in FIG. 3, the through-hole 39 is formed in the center of the protective substrate 31 in the Y-axis direction so as to penetrate in the Z-axis direction. A wiring board 120, which will be described later, is inserted into the through-hole 39.

[0031] 5, the actuator 150 of the vibration section 30 is disposed on a vibration plate 155 inside the recess 33. The actuator 150 vibrates the vibration plate 155 to apply pressure to the liquid in the pressure chamber 12. The actuator 150 has a piezoelectric element 160 and wiring 180.

[0032] The piezoelectric element 160 is laminated on the vibration plate 155 at a position overlapping the pressure chamber 12. More specifically, the piezoelectric element 160 is provided on the upper surface of the vibration plate 155 at a position overlapping the pressure chamber 12 when viewed in the stacking direction. The upper surface of the vibration plate 155 is the surface of the vibration plate 155 opposite to the side on which the pressure chamber 12 exists. The upper surface of the vibration plate 155 is also referred to as the first surface. When ejecting liquid, the vibration plate 155 is vibrated by driving the piezoelectric element 160, and pressure is applied to the liquid in the pressure chamber 12. The piezoelectric element 160 is also referred to as the first piezoelectric element.

[0033] The piezoelectric element 160 has a plurality of first electrodes 165, a second electrode 170, and a piezoelectric body 175. The first electrodes 165 are arranged on the vibration plate 155 at positions overlapping the corresponding pressure chambers 12. The first electrodes 165 are also referred to as individual electrodes. The second electrodes 170 are arranged at positions farther from the pressure chambers 12 than the first electrodes 165 in the stacking direction. The second electrodes 170 are an electrode common to the plurality of first electrodes 165. The second electrodes 170 are arranged over an area overlapping with all of the plurality of first electrodes 165. The second electrodes 170 are also referred to as common electrodes. Since the first electrodes 165 provided for each pressure chamber 12 are arranged close to the vibration plate 155, the piezoelectric strain of the piezoelectric element 160 can be efficiently propagated to the vibration plate 155. The first electrode 165 and the second electrode 170 are formed of various metals such as platinum, iridium, titanium, tungsten, and tantalum, or conductive metal oxides such as lanthanum nickelate (LaNiO3).

[0034] The piezoelectric body 175 is provided between the first electrode 165 and the second electrode 170. The piezoelectric body 175 is also referred to as a first piezoelectric body. The piezoelectric body 175 is made of lead zirconate titanate (PZT). Note that the piezoelectric body 175 may be made of other types of ceramic materials having a so-called perovskite structure represented by the ABO3 type instead of PZT. Examples of ceramic materials include barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, zinc oxide, barium strontium titanate (BST), strontium bismuth tantalate (SBT), lead metaniobate, lead zinc niobate, and lead scandium niobate.

[0035] The wiring 180 electrically connects the first electrode 165 to the drive circuit 121, which will be described later. The wiring 180 is made of a conductive material. Although not shown in FIG. 5, the second electrode 170 and the drive circuit 121 are electrically connected by other wiring made of a conductive material. The actuator 150 can be formed, for example, by etching using photoresist masking. The function of the actuator 150 will be described in detail below.

[0036] The diaphragm 155 of the vibrating section 30 is laminated on the pressure chamber substrate 10 at positions overlapping with the pressure chambers 12 and the absorption chambers 13 in the lamination direction. The diaphragm 155 is arranged so as to cover the pressure chambers 12 and the absorption chambers 13. The diaphragm 155 has a flexible layer 156 formed on the pressure chamber substrate 10, and a protective layer 157 formed on the flexible layer 156. The flexible layer 156 is made of, for example, silicon dioxide. The protective layer 157 is made of, for example, zirconium oxide. Note that the pressure chamber substrate 10 and at least a portion of the diaphragm 155 may be formed as an integral member.

[0037] The absorbing section 200 of the vibration section 30 is disposed on the vibration plate 155 inside the recess 33. The absorbing section 200 has a piezoelectric element 210. The piezoelectric element 210 is laminated on the vibration plate 155 at a position overlapping with the absorption chamber 13. More specifically, the piezoelectric element 210 is provided on the upper surface of the vibration plate 155 at a position overlapping with the absorption chamber 13 when viewed in the lamination direction. The piezoelectric element 210 absorbs at least a portion of the vibration of the liquid propagated from the pressure chamber 12 to the absorption chamber 13. The piezoelectric element 210 is also referred to as a second piezoelectric element. The piezoelectric element 210 has a third electrode 215, a fourth electrode 220, and a piezoelectric body 225. The piezoelectric body 225 is also referred to as a second piezoelectric body. The third electrode 215 is provided on the vibration plate 155 at a position overlapping with the absorption chamber 13. The fourth electrode 220 is disposed at a position farther from the absorption chamber 13 than the third electrode 215 in the stacking direction. The fourth electrode 220 is also disposed at a position overlapping the absorption chamber 13. The fourth electrode 220 and the third electrode 215 are electrically connected to a voltage detection circuit 122 (described later) by wiring made of a conductive material (not shown). The voltage detection circuit 122 is also referred to as a pressure detection unit.

[0038] The piezoelectric body 225 is provided between the third electrode 215 and the fourth electrode 220. The piezoelectric body 225 is formed, for example, to have a uniform thickness. The material forming the piezoelectric body 225 is preferably the same as that of the piezoelectric body 175. The material forming the third electrode 215 and the fourth electrode 220 is preferably the same as that of the first electrode 165 and the second electrode 170. By using a common material in this way, the piezoelectric element 160 of the actuator 150 and the piezoelectric element 210 of the absorbing section 200 can be manufactured in the same process. This simplifies the manufacturing process and reduces costs. The material of the piezoelectric body 225 may be different from that of the piezoelectric body 175. In this case, for example, an organic piezoelectric material can be used as the material of the piezoelectric body 225. Examples of organic piezoelectric materials include polyfluorovinylidene (PVDF), a fluorine-based polymer semiconductor material, polyfluorovinylidene-trifluoroethylene copolymer (P(VDF-TrFE)) in which polyfluorovinylidene (PVDF) is copolymerized with trifluoroethylene (TrFE), polylactic acid, and polyamino acids.

[0039] The third electrode 215 and the fourth electrode 220 may be arranged so as to overlap the entire piezoelectric body 225. Alternatively, they may be arranged so as to overlap at least a part of the piezoelectric body 225. The function of the absorbing section 200 will be described in detail later.

[0040] As shown in FIG. 2, the case member 40 is disposed on the +Z side of the head main body 11. As shown in FIG. 3, the case member 40 has a liquid chamber 42, a connection port 43, and two liquid circulation ports 44. The liquid chamber 42, together with the first common liquid chamber 17 and the second common liquid chamber 18, forms a common liquid chamber 25 through which liquid flows. The connection port 43 is an opening that penetrates the case member 40 in the Z-axis direction. A wiring board 120 is inserted into the connection port 43. The liquid circulation port 44 is a hole that penetrates the case member 40 in the Z-axis direction. Liquid flows into the liquid ejection head 100 from the liquid circulation port 44. The case member 40 is formed from, for example, a resin material or a metal material.

[0041] The wiring board 120 is provided with a drive circuit 121 and a voltage detection circuit 122. The drive circuit 121 is a circuit for driving the actuator 150. The drive circuit 121 is electrically connected to the first electrode 165 via the wiring board 120 and wiring 180. The drive circuit 121 is also electrically connected to the second electrode 170 via the wiring board 120 and wiring (not shown). The drive circuit 121 is also electrically connected to the control unit 500 via the wiring board 120 and wiring (not shown).

[0042] The drive circuit 121 generates a drive signal for driving the actuator 150 based on a control signal supplied from the control unit 500. The drive circuit 121 is also referred to as a drive unit. The drive signal is also referred to as a first drive signal. The drive circuit 121 supplies the drive signal to the first electrode 165 with the second electrode 170 set to a reference potential.

[0043] The voltage detection circuit 122 is electrically connected to the third electrode 215 via the wiring board 120 and a wiring (not shown). The voltage detection circuit 122 is also electrically connected to the fourth electrode 220 via the wiring board 120 and a wiring (not shown). Furthermore, the voltage detection circuit 122 is electrically connected to the control unit 500 via the wiring board 120 and a wiring (not shown).

[0044] The voltage detection circuit 122 detects the electromotive force of the piezoelectric element 210 and outputs a signal indicating the detected electromotive force of the piezoelectric element 210 to the control unit 500. For example, after the piezoelectric element 160 is driven to eject liquid, residual vibration of the liquid that has propagated from the pressure chamber 12 to the absorption chamber 13 is propagated to the piezoelectric element 210 via the vibration plate 155. The residual vibration generates an electromotive force in the piezoelectric element 210. Although the drive circuit 121 and the voltage detection circuit 122 are provided separately in FIG. 3, they may also be provided on a single substrate.

[0045] The functions of the pressure chamber 12 and the actuator 150 are described below. The actuator 150 applies pressure to the liquid in the pressure chamber 12 by vibrating the diaphragm 155. Specifically, a drive signal is supplied to the first electrode 165 while the second electrode 170 is set to a reference potential. The reference potential is, for example, ground potential. The drive signal is, for example, a signal whose applied voltage changes over time. When a voltage is applied to the first electrode 165 and the second electrode 170, piezoelectric strain occurs in the portion of the piezoelectric body 175 sandwiched between the first electrode 165 and the second electrode 170. In this manner, the actuator 150 is driven. When the actuator 150 is driven, the diaphragm 155 vibrates. Note that no piezoelectric strain occurs in the portion of the piezoelectric body 175 that is not sandwiched between the first electrode 165 and the second electrode 170. When pressure is applied to the liquid in the pressure chamber 12, the liquid is ejected from the nozzle 21 via the first communication channel 16. The nozzle 21, the pressure chamber 12, the vibration plate 155, and the piezoelectric element 160 are collectively referred to as an ejection portion.

[0046] Next, the functions of the absorption chamber 13 and the absorption unit 200 will be described. As described above, when pressure is applied to the liquid in the pressure chamber 12 by driving the actuator 150, part of the liquid in the pressure chamber 12 is ejected to the outside from the nozzle 21 located downstream, while another part of the liquid in the pressure chamber 12 flows into the absorption chamber 13 located upstream of the pressure chamber 12 and common to multiple pressure chambers 12. As a result, vibrations of the liquid are propagated from the pressure chamber 12 to the absorption chamber 13. The piezoelectric element 210 of the absorption unit 200 bends in response to the vibrations of the liquid propagated to the absorption chamber 13, thereby absorbing the vibrations of the liquid. This makes it possible to keep the pressure inside the absorption chamber 13 below a certain pressure. Furthermore, it is possible to reduce the pressure inside the pressure chamber 12 connected to the absorption chamber 13.

[0047] 5, the pressure chamber 12 and the absorption chamber 13 are provided at the same position in the Z-axis direction and adjacent to each other in the Y-axis direction, so that the absorption chamber 13 can effectively absorb vibrations of the liquid transmitted from the pressure chamber 12. It is preferable to form the absorption section 200 so that it has flexibility suitable for absorbing vibrations of the liquid transmitted from the pressure chamber 12 by adjusting the material that forms the absorption section 200 and the thickness of the absorption section 200.

[0048] Furthermore, in the first embodiment, the absorption section 200 is used to detect the pressure of the liquid inside the absorption chamber 13. The control section 500 detects the pressure of the liquid inside the absorption chamber 13 based on the electromotive force of the piezoelectric element 210. Specifically, the control section 500 detects a change in the electromotive force of the piezoelectric element 210 from a signal supplied from the voltage detection circuit 122. The control section 500 determines whether the pressure inside the absorption chamber 13 and the pressure chamber 12 is normal or abnormal from the change in pressure inside the absorption chamber 13 indicated by the change in electromotive force of the piezoelectric element 210.

[0049] If the pressure state inside the pressure chamber 12 and the absorption chamber 13 becomes abnormal, the liquid may not be ejected normally. Alternatively, if the pressure state inside the pressure chamber 12 and the absorption chamber 13 becomes abnormal, the stability of the quality of the liquid ejected from the nozzle 21 may decrease.

[0050] Abnormal pressures in the absorption chamber 13 and the pressure chamber 12 can occur for the following reasons, for example: Air bubbles may become trapped in the pressure chamber 12 during liquid ejection. In this case, the pressures in the pressure chamber 12 and the absorption chamber 13 become higher than normal when no air bubbles are trapped. If the viscosity of the liquid increases due to a drop in temperature, the pressures in the pressure chamber 12 and the absorption chamber 13 during liquid ejection may change from normal. If the amount of liquid supplied to the liquid flow path including the pressure chamber 12 and the absorption chamber 13 becomes insufficient due to a malfunction of a pump (not shown) that sends liquid to the liquid flow path including the pressure chamber 12 and the absorption chamber 13, the pressures in the pressure chamber 12 and the absorption chamber 13 during liquid ejection may also change from normal. Furthermore, the pressures in the pressure chamber 12 and the absorption chamber 13 may change from normal due to malfunctions in the cartridge installation / removal, malfunctions during initial liquid filling, etc.

[0051] When the control unit 500 determines that the pressure state inside the absorption chamber 13 and the pressure chamber 12 is abnormal, it displays a message warning of the occurrence of an abnormality on, for example, a display provided in the liquid ejection device 300. Alternatively, the control unit 500 executes a cleaning process for the liquid ejection head 100 by ejecting liquid from the nozzles 21.

[0052] In the first embodiment, the liquid ejection device 300 detects changes in pressure in the absorption chamber 13 from changes in electromotive force generated by a piezoelectric element 210, which is different from the piezoelectric element 160 that applies pressure to the pressure chamber 12. This allows the liquid ejection operation during printing and the operation of detecting the pressure of the liquid inside the pressure chamber 12 and the absorption chamber 13 to be performed simultaneously. Therefore, changes in the pressure of the liquid inside the pressure chamber 12 and the absorption chamber 13 can be detected not only when the liquid is not being ejected, but also when the liquid is being ejected. Conventionally, changes in the pressure inside the pressure chamber 12 could not be detected when the liquid is being ejected. However, with the configuration according to the first embodiment, changes in the pressure inside the pressure chamber 12 can be detected even when the liquid is being ejected. Therefore, abnormalities in the pressure state inside the pressure chamber 12 can be detected even when the liquid is being ejected.

[0053] Furthermore, in the first embodiment, changes in liquid pressure are detected in the absorption chamber 13 shared by multiple pressure chambers 12. For example, if changes in liquid pressure were detected in each individual pressure chamber 12, it would be necessary to provide a mechanism for detecting pressure changes for each pressure chamber 12 and monitor each pressure chamber 12, which would complicate the configuration required for pressure detection. However, in the first embodiment, changes in liquid pressure are detected in the common absorption chamber 13, which allows for a simple configuration for detecting pressure changes.

[0054] Furthermore, because the liquid ejection operation during printing and the liquid pressure detection operation within the absorption chamber can be performed simultaneously, there is no need to stop the liquid ejection operation in order to detect the pressure, thereby reducing the waiting time for the printing operation.

[0055] FIG. 9 is a diagram showing an example of the arrangement of drive wiring connected to the piezoelectric element 160 and detection wiring connected to the piezoelectric element 210. Note that FIG. 9 does not show the piezoelectric body 175, the piezoelectric body 225, the drive circuit 121, and the voltage detection circuit 122. The drive wiring includes a wiring 180 connecting the first electrode 165 and the drive circuit 121, and a wiring 185 connecting the second electrode 170 and the drive circuit 121. The wiring 180 is also referred to as a first drive wiring. The wiring 185 is also referred to as a second drive wiring. At least a portion of the wiring 180 and the wiring 185 extends along the second direction. Since the number of second electrodes 170 provided corresponds to the number of nozzles 21, the number of wirings 180 also corresponds to the number of nozzles 21. The plurality of wirings 180 is also referred to as a first drive wiring group.

[0056] The detection wiring includes wiring 230 connecting third electrode 215 and voltage detection circuit 122, and wiring 235 connecting fourth electrode 220 and voltage detection circuit 122. Wiring 230 is also referred to as a first detection wiring. Wiring 235 is also referred to as a second detection wiring. At least a portion of wiring 230 and wiring 235 extends along the second direction.

[0057] As described above, the drive circuit 121 supplies a drive signal to the first electrode 165 via the wiring 180 while setting the second electrode 170 to a reference potential via the wiring 185. Here, the drive signal supplied to the first electrode 165 via the wiring 180 is a signal whose applied voltage changes over time, and therefore electrical noise is likely to be generated from the wiring 180. On the other hand, the reference potential set for the second electrode 170 is a constant voltage, and electrical noise is less likely to be generated from the wiring 185 than from the wiring 180. Therefore, in the example shown in FIG. 9 , the wiring 185 is disposed between the wiring 230 and the wiring group of the wiring 180, which is prone to generating noise. By providing a distance between the wiring 230 and the wiring group of the wiring 180, the influence of noise generated from the wiring 180 on the wiring 230 and the wiring 235 can be reduced. Furthermore, by shielding the noise generated on the wiring 180 with the wiring 185, the influence of the noise on the wiring 230 and the wiring 235 can be reduced. As a result, the influence of the noise that is received when the voltage detection circuit 122 detects the change in the electromotive force of the piezoelectric element 210 can be suppressed, and the change in pressure in the absorption chamber 13 can be detected with higher accuracy.

[0058] A2. Embodiment 2: In the second embodiment, another example of the configuration of the piezoelectric element 210 of the absorbing section 200 will be described. The following description will focus on configurations that are different from the first embodiment, and descriptions of configurations that are the same as those in the first embodiment will be omitted.

[0059] Fig. 6 is a diagram showing the arrangement of the piezoelectric body 225 of the piezoelectric element 210. Fig. 6 shows the arrangement of the piezoelectric body 225 when the piezoelectric element 210 is viewed in the -Z direction within the recess 33. Note that the fourth electrode 220 is not shown in Fig. 6 to facilitate understanding. The positions of the pressure chamber 12, the absorption chamber 13, and the communication path Cm1 are indicated by dashed lines. The position of the nozzle 21 is also indicated by dashed lines.

[0060] As shown in FIG. 6, when viewed in the Z-axis direction, the absorption chamber 13 includes a first region 2251 and a second region 2252 surrounding the first region 2251. When viewed in the Z-axis direction, the piezoelectric body 225 overlapping the second region 2252 has a predetermined thickness. When viewed in the Z-axis direction, the piezoelectric body 225 overlapping the first region 2251 has a thickness set to be smaller than the thickness of the second region 2252. Alternatively, when viewed in the Z-axis direction, the piezoelectric body 225 is provided so as to overlap the second region 2252, while the piezoelectric body 225 is not provided so as to overlap the first region 2251. Note that the thickness of the piezoelectric body 225 refers to the thickness in the Z-axis direction.

[0061] In the region of the piezoelectric body 225 overlapping with the absorption chamber 13, a first region 2251 in which the piezoelectric body 225 is formed thin is provided, so the degree of deflection of the piezoelectric body 225 can be made larger than when the thickness of the piezoelectric body 225 is uniform.

[0062] Furthermore, a portion of the second region 2252 is formed continuously from a position corresponding to one end of the absorption chamber 13 in the Y-axis direction to a position corresponding to the other end thereof. Since the absorption chamber 13 is formed as a space with the X-axis direction as the longitudinal direction and the Y-axis direction as the lateral direction, the displacement amount of the piezoelectric element 210 in the Y-axis direction is larger than the displacement amount in the X-axis direction. Since the second region 2252 includes a portion that is continuous in the Y-axis direction, the stress applied to the piezoelectric body 225 is dispersed, and vibrations of the liquid propagated from the pressure chamber 12 can be efficiently absorbed.

[0063] The third electrode 215 and the fourth electrode 220 are formed continuously in a region overlapping with the absorption chamber 13 in the stacking direction, from a position corresponding to one end of the absorption chamber 13 in the Y-axis direction to a position corresponding to the other end. The absorption chamber 13 is formed as a space with the X-axis direction as the longitudinal direction and the Y-axis direction as the lateral direction, so the displacement amount of the piezoelectric element 210 in the Y-axis direction is larger than the displacement amount in the X-axis direction. Because the third electrode 215 and the fourth electrode 220 are formed continuously in the Y-axis direction, a larger electromotive force can be detected using the piezoelectric element 210.

[0064] Alternatively, in the region where the piezoelectric element 210 and the absorption chamber 13 overlap, no piezoelectric body may be formed in the first region 2251, and the piezoelectric body 225 may be formed in the second region 2252 surrounding the first region 2251. Since the first region 2251 where no piezoelectric body is formed is surrounded by the second region 2252 where the piezoelectric body 225 is formed, the degree of deflection of the piezoelectric body 225 can be made larger compared to when the thickness of the piezoelectric body 225 is uniform.

[0065] The arrangement of the first regions 2251 and the second regions 2252 shown in FIG. 6 is one example. In the example shown in FIG. 6, the first regions 2251 corresponding to each pressure chamber 12 are arranged along the X-axis direction. The first regions 2251 are arranged at the same position in the X-axis direction as the corresponding pressure chambers 12. Each pressure chamber 12 is associated with a pair of the first region 2251 in which no piezoelectric body is formed and the second region 2252 surrounding the first region 2251 and in which the piezoelectric body 225 is formed. Alternatively, one pair of the first region 2251 and the second region 2252 may be arranged such that one pair of the first region 2251 and the second region 2252 corresponds to two or more pressure chambers 12. Furthermore, the second region 2252 does not necessarily have to surround the first region 2251.

[0066] A3. Embodiment 3: In the third embodiment, an example will be described in which the absorbing member 200 and the actuator 150 are integrally formed. The following description will focus on configurations that differ from the first embodiment, and descriptions of configurations that are the same as those in the first embodiment will be omitted.

[0067] 7 is an enlarged view of the vibrating section 30 according to the third embodiment. In the third embodiment, the piezoelectric body 225 of the absorbing section 200 is formed integrally with the piezoelectric body 175 of the actuator 150. In the example shown, the piezoelectric body 225 is the portion sandwiched between the first electrode 165 and the second electrode 170. The piezoelectric body 175 is the portion sandwiched between the third electrode 215 and the fourth electrode 220. Because the piezoelectric body 175 of the actuator 150 and the piezoelectric body 225 of the absorbing section 200 are formed as a continuous piezoelectric body, the effort required to form the piezoelectric bodies can be simplified compared to when the piezoelectric body 175 and the piezoelectric body 225 are formed separately.

[0068] Note that no piezoelectric distortion occurs in the portions of the integrally formed piezoelectric body 175 and piezoelectric body 225 that are not sandwiched between the electrodes. Therefore, driving the actuator 150 does not affect the detection result of the pressure of the absorbing section 200.

[0069] A4. Embodiment 4: In the first to fourth embodiments, an example has been described in which the absorbing part 200 having the piezoelectric element 210 is disposed above the absorbing chamber 13, but the position at which the absorbing part 200 is disposed is not limited to this.

[0070] 8 is a schematic diagram showing the arrangement of the absorption section 200 according to the fourth embodiment. In the fourth embodiment, the absorption section 200 is arranged on the side surface of the pressure chamber 12 and the absorption chamber 13. In the example shown, the side surface is a plane parallel to the YZ plane of the pressure chamber 12 and the absorption chamber 13. In this case, the absorption section 200 is not provided on the vibration plate 155, but is provided on the pressure chamber substrate 10 that forms the pressure chamber 12 and the absorption chamber 13. Unlike the first embodiment, by arranging the absorption section 200 so as to overlap the pressure chamber 12 in addition to the absorption chamber 13, it is possible to improve the accuracy of detecting the pressure of the liquid.

[0071] Furthermore, when the nozzle 21 is not provided on the -Z side of the pressure chamber 12, the absorption section 200 may be disposed on the bottom surfaces of the pressure chamber 12 and the absorption chamber 13. In this case, too, by disposing the absorption section 200 so as to overlap the pressure chamber 12 in addition to the absorption chamber 13, it is possible to improve the accuracy of detecting the pressure of the liquid.

[0072] B. Other Embodiments In the first embodiment, an example has been described in which one absorption chamber 13 is connected to a plurality of pressure chambers 12. However, one absorption chamber 13 may be connected to a set number of pressure chambers 12. For example, one absorption chamber 13 may be connected to ten pressure chambers 12. If the liquid ejection device 300 has 50 pressure chambers 12, five absorption chambers 13 will be provided. Even in such a case, since changes in liquid pressure are detected by the absorption chamber 13 common to the plurality of pressure chambers 12, the configuration for detecting changes in pressure can be simplified.

[0073] Alternatively, an absorption chamber 13 may be provided for each pressure chamber 12. In this case, it is possible to determine whether the internal pressure state is normal or abnormal for each pressure chamber 12. Furthermore, it is possible to check the distribution of the internal pressure state for multiple pressure chambers 12.

[0074] Furthermore, the control unit 500 of the liquid ejection device 300 drives the first piezoelectric element to eject liquid from the nozzle 21, and can therefore simultaneously perform an ejection operation that applies pressure to the liquid in the pressure chamber and a detection operation that detects the pressure of the liquid in the absorption chamber from the electromotive force of the second piezoelectric element, but the control unit 500 does not necessarily need to simultaneously perform the ejection operation and the detection operation.

[0075] In the first embodiment, an example has been described in which the piezoelectric element 160 and the piezoelectric element 210 are manufactured from the same material. In this case, the number of types of materials required can be reduced. Alternatively, the piezoelectric element 160 and the piezoelectric element 210 may be manufactured from different materials. In this case, the piezoelectric element 160 may be configured to be a piezoelectric element suitable for discharging liquid. Furthermore, the piezoelectric element 210 may be configured to be a piezoelectric element suitable for absorbing vibrations and detecting the pressure of the liquid in the absorption chamber 13.

[0076] Furthermore, in the first embodiment, an example has been described in which, in the piezoelectric element 160 of the actuator 150, the second electrode 170, which is a common electrode, is arranged above the piezoelectric body 175, and the first electrode 165, which is an individual electrode, is arranged below the piezoelectric body 175. However, the individual electrodes may be arranged above the piezoelectric body 175, and the common electrode may be arranged below the piezoelectric body 175.

[0077] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0078] C. Other forms: (1) According to a first aspect of the present disclosure, there is provided a liquid ejection device. This liquid ejection device comprises a flow path substrate having one or more pressure chambers that form a flow path for the liquid, at least one absorption chamber connected to the pressure chamber, forming the flow path for the liquid together with the pressure chamber, and absorbing vibrations of the liquid propagated from the pressure chamber, and a nozzle connected to the pressure chamber and ejecting the liquid; a vibration plate stacked on the flow path substrate at a position overlapping with the pressure chamber and the absorption chamber in the stacking direction; a first piezoelectric element provided on one surface of the vibration plate, which is the surface opposite to the side on which the pressure chamber is located, at a position overlapping with the pressure chamber in the stacking direction, the first piezoelectric element vibrating the vibration plate to apply pressure to the liquid in the pressure chamber; a second piezoelectric element provided on the first surface of the vibration plate at a position overlapping with the absorption chamber in the stacking direction, the second piezoelectric element deforming to absorb at least a portion of the vibrations of the liquid propagated from the pressure chamber; and a pressure detection unit that detects the pressure of the liquid inside the absorption chamber based on the electromotive force of the second piezoelectric element. According to the above aspect, a change in pressure in the absorption chamber can be detected from a change in electromotive force generated by the second piezoelectric element, which is different from the first piezoelectric element that applies pressure to the liquid in the pressure chamber. Therefore, when the discharge unit is driven to discharge liquid, a change in pressure of the liquid near the pressure chamber of the discharge unit can be detected.

[0079] (2) In the liquid ejection device of the above aspect, the one or more pressure chambers may be a plurality of pressure chambers, and at least one of the absorption chambers may be provided in common to the plurality of pressure chambers. According to this configuration, the pressure change of the liquid transmitted from the multiple pressure chambers is detected in a common absorption chamber, which simplifies the configuration for detecting the pressure change of the liquid compared to when the pressure change of the liquid is detected in each individual pressure chamber.

[0080] (3) In the liquid ejection device of the above form, the first piezoelectric element may have a first electrode, a second electrode provided at a position farther from the vibration plate than the first electrode, and a first piezoelectric body provided between the first electrode and the second electrode in the stacking direction, and the second piezoelectric element may have a third electrode, a fourth electrode provided at a position farther from the vibration plate than the third electrode in the stacking direction, and a second piezoelectric body provided between the third electrode and the fourth electrode in the stacking direction. According to this aspect, the first electrode of the first piezoelectric element provided for each pressure chamber is disposed close to the vibration plate, so that the piezoelectric strain of the first piezoelectric element can be efficiently propagated to the vibration plate.

[0081] (4) In the liquid ejection device of the above aspect, when the absorption chamber is viewed in the stacking direction, the absorption chamber may have a first region and a second region, and the thickness of the piezoelectric body overlapping the first region when viewed in the stacking direction may be smaller than the thickness of the piezoelectric body overlapping the second region when viewed in the stacking direction. According to this configuration, the first region in which the piezoelectric body is formed thin is provided in the region overlapping the absorption chamber, so the degree of deflection of the piezoelectric body can be increased compared to when the thickness of the piezoelectric body is uniform, thereby improving the function of absorbing vibrations of the liquid transmitted from the pressure chamber.

[0082] (5) In the liquid ejection device of the above embodiment, when the absorption chamber is viewed in the stacking direction, the absorption chamber may have a first region and a second region, and the piezoelectric body may overlap the second region but not overlap the first region when viewed in the stacking direction. According to this embodiment, since there is provided a first region where no piezoelectric body is formed and a second region where a piezoelectric body is formed, the degree of deflection of the piezoelectric body can be increased compared to when the thickness of the piezoelectric body is uniform, thereby improving the function of absorbing vibrations of the liquid propagated from the pressure chamber.

[0083] (6) In the liquid ejection device of the above form, the absorption chamber is formed as a space having a first direction as its longitudinal direction, and the pressure chamber is formed as a space having a second direction as its longitudinal direction that intersects the first direction and the stacking direction, and in the second piezoelectric element, a portion of the second region may be formed continuously from a position corresponding to one end of the absorption chamber in the second direction to a position corresponding to the other end. The amount of displacement in the second direction, which is the short side direction of the absorption chamber, is greater than the amount of displacement in the first direction, which is the long side direction. Therefore, by having a portion of the second region include a continuous portion in the second direction, the stress applied to the piezoelectric body is dispersed, and vibrations of the liquid transmitted from the pressure chamber can be efficiently absorbed.

[0084] (7) In the liquid ejection device of the above aspect, the third electrode and the fourth electrode may be formed continuously in a region overlapping with the absorption chamber in the stacking direction from a position corresponding to one end of the absorption chamber in the second direction to a position corresponding to the other end. The amount of displacement in the second direction, which is the short direction of the absorption chamber, is greater than the amount of displacement in the first direction, which is the long direction. Therefore, by forming the third electrode and the fourth electrode continuously in the second direction, a larger electromotive force can be detected, thereby improving the accuracy of pressure detection.

[0085] (8) In the liquid ejection device of the above aspect, the liquid ejection device may further include a first drive wiring group connected to the first electrode, the first drive wiring group including a plurality of first drive wirings extending along a second direction intersecting a first direction in which the plurality of pressure chambers are arranged and the stacking direction; at least one second drive wiring connected to the second electrode; a drive unit that supplies a first drive signal to the first electrode via the first drive wiring and sets the second electrode to a reference potential via the second drive wiring; and a first detection wiring that connects the third electrode and the pressure detection unit, wherein the second drive wiring may be arranged between the first drive wiring group and the first detection wiring in the first direction. According to this embodiment, by providing second drive wiring, which generates less noise than the first drive wiring group, between the first drive wiring group, which is prone to generating noise, and the first detection wiring, the first drive wiring group and the first detection wiring can be physically separated, thereby reducing the effect of noise generated from the first drive wiring group on the first detection wiring.

[0086] (9) In the liquid ejection device of the above aspect, a second detection wiring may be further provided that connects the fourth electrode and the pressure detection unit, and the second drive wiring may be arranged between the first drive wiring group and the second detection wiring. According to this embodiment, by providing second drive wiring, which generates less noise than the first drive wiring group, between the first drive wiring group, which is prone to generating noise, and the second detection wiring, the first drive wiring group and the second detection wiring can be physically separated, thereby reducing the effect of noise generated from the first drive wiring group on the second detection wiring.

[0087] (10) In the liquid ejection device of the above aspect, the first piezoelectric element and the second piezoelectric element may be formed as a continuous piezoelectric element. According to this embodiment, the first piezoelectric body and the second piezoelectric body are integrally formed, which simplifies the work involved in forming the piezoelectric body compared to when the first piezoelectric body and the second piezoelectric body are formed separately.

[0088] (11) In the liquid ejection device of the above aspect, a control unit may be further provided that drives the first piezoelectric element and the second piezoelectric element, and the control unit may simultaneously perform an ejection operation that applies pressure to the liquid in the pressure chamber and a detection operation that detects the pressure of the liquid in the absorption chamber from the electromotive force of the second piezoelectric element to eject the liquid from the nozzle by driving the first piezoelectric element. According to this configuration, the liquid ejection operation during printing and the liquid pressure detection operation in the absorption chamber can be performed simultaneously, so there is no need to stop the liquid ejection operation for the pressure detection operation, thereby shortening the waiting time for the printing operation.

[0089] The present disclosure is not limited to the above-described liquid ejection apparatus, but can be realized in various other forms, such as a liquid ejection system and a multifunction peripheral including a liquid ejection apparatus. [Explanation of symbols]

[0090] 10...pressure chamber substrate, 11...head main body, 12...pressure chamber, 13...absorption chamber, 14...support portion, 15...communication plate, 16...first communication flow path, 17...first common liquid chamber, 18...second common liquid chamber, 19...second communication flow path, 20...nozzle substrate, 21...nozzle, 25...common liquid chamber portion, 30...vibration portion, 31...protective substrate, 33...recess, 38...atmosphere communication hole, 39...through hole, 40...case member, 42...liquid chamber portion, 43...connection port, 44...liquid distribution port, 100...liquid ejection head, 120...wiring substrate, 121...drive circuit, 122...voltage detection circuit, 150...actuator, 155...vibration plate, 156...flexible layer, 157...protective layer, 160...piezoelectric element, 165...first electrode, 170...second electrode, 175...piezoelectric body, 180...wiring, 185...wiring, 200...absorption section, 210...piezoelectric element, 215...third electrode, 220...fourth electrode, 225...piezoelectric body, 230...wiring, 235...wiring, 300...liquid ejection device, 310...liquid container, 312...tube, 320...head moving mechanism, 321...drive belt, 322...carriage, 326...movement motor, 327...pulley, 330...conveyance mechanism, 332...conveyance roller, 334...conveyance rod, 336...conveyance motor, 500...control section, 2251...first region, 2252...second region, Cm1...communication path, L1...nozzle row, L2...nozzle row, O...center plane, P...printing paper

Claims

1. A liquid ejection device, a flow path substrate having one or more pressure chambers forming a flow path for the liquid, at least one absorption chamber connected to the pressure chamber, forming the flow path for the liquid together with the pressure chamber, and absorbing vibrations of the liquid propagated from the pressure chamber, and a nozzle connected to the pressure chamber and ejecting the liquid; a vibration plate laminated on the flow path substrate at a position overlapping the pressure chamber and a position overlapping the absorption chamber when viewed in a lamination direction; a first piezoelectric element provided on a first surface, which is one surface of the vibration plate and is opposite to a surface on which the pressure chamber is present, at a position overlapping with the pressure chamber when viewed in the stacking direction, the first piezoelectric element vibrating the vibration plate to apply pressure to the liquid in the pressure chamber; a second piezoelectric element provided on the first surface of the vibration plate at a position overlapping with the absorption chamber in the stacking direction, the second piezoelectric element deforming to absorb at least a part of the vibration of the liquid propagated from the pressure chamber; a pressure detection unit that detects the pressure of the liquid inside the absorption chamber based on the electromotive force of the second piezoelectric element; A liquid ejection device comprising:

2. The liquid ejection device according to claim 1 , the one or more pressure chambers are a plurality of pressure chambers, At least one of the absorption chambers is provided in common to the plurality of pressure chambers. Liquid discharge device.

3. The liquid ejection device according to claim 2, the first piezoelectric element has a first electrode, a second electrode provided at a position farther from the vibration plate than the first electrode, and a first piezoelectric body provided between the first electrode and the second electrode in the stacking direction; the second piezoelectric element has a third electrode, a fourth electrode provided at a position farther from the vibration plate than the third electrode in the stacking direction, and a second piezoelectric body provided between the third electrode and the fourth electrode in the stacking direction. Liquid discharge device.

4. The liquid ejection device according to claim 3, When the absorption chamber is viewed in the stacking direction, the absorption chamber has a first region and a second region, The thickness of the second piezoelectric element overlapping the first region when viewed in the stacking direction is smaller than the thickness of the second piezoelectric element overlapping the second region when viewed in the stacking direction. Liquid discharge device.

5. The liquid ejection device according to claim 3, When the absorption chamber is viewed in the stacking direction, the absorption chamber has a first region and a second region, the second piezoelectric body overlaps the second region and does not overlap the first region when viewed in the stacking direction; Liquid discharge device.

6. 6. The liquid ejection device according to claim 4, The absorption chamber is formed as a space having a first direction as a longitudinal direction, The pressure chamber is formed as a space having a longitudinal direction in a second direction intersecting the first direction and the stacking direction, the second piezoelectric body is formed continuously from a position corresponding to one end of the absorption chamber in the second direction to a position corresponding to the other end of the absorption chamber. Liquid discharge device.

7. The liquid ejection device according to claim 6, the third electrode and the fourth electrode are continuously formed in a region overlapping with the absorption chamber in the stacking direction from a position corresponding to one end of the absorption chamber in the second direction to a position corresponding to the other end of the absorption chamber in the second direction. Liquid discharge device.

8. The liquid ejection device according to claim 3, a first drive wiring group connected to the first electrode, the first drive wiring group including a plurality of first drive wirings extending along a first direction in which the plurality of pressure chambers are arranged and a second direction intersecting the stacking direction; At least one second drive wiring connected to the second electrode; a drive section that supplies a first drive signal to the first electrode via the first drive wiring and sets the second electrode to a reference potential via the second drive wiring; a first detection wiring that connects the third electrode and the pressure detection unit; having In the first direction, the second drive wiring is disposed between the first drive wiring group and the first detection wiring. Liquid discharge device.

9. The liquid ejection device according to claim 8, a second detection wiring that connects the fourth electrode and the pressure detection unit; the second drive wiring is disposed between the first drive wiring group and the second detection wiring; Liquid discharge device.

10. 10. The liquid ejection device according to claim 3, The first piezoelectric body and the second piezoelectric body are formed as a continuous piezoelectric body. Liquid discharge device.

11. The liquid ejection device according to any one of claims 1 to 10, A control unit that drives the first piezoelectric element and the second piezoelectric element is further provided, The control unit is a discharge operation of applying pressure to the liquid in the pressure chamber by driving the first piezoelectric element to discharge the liquid from the nozzle; a detection operation of detecting a pressure of the liquid in the absorption chamber from an electromotive force of the second piezoelectric element; simultaneously, Liquid discharge device.

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