Liquid ejection head and liquid ejection apparatus

Abstract

The invention provides a liquid ejecting head and a liquid ejecting apparatus capable of improving the accuracy of fluid resistance. A liquid ejection head according to one embodiment includes a plurality of flow substrates. The plurality of flow substrates are stacked in the stacking direction and have openings for forming flow paths formed therein. At least one of the flow path substrates has a slit. The flow path formed by the slits has a flow path cross-section, and the dimension of the flow path cross-section in the longitudinal direction orthogonal to the extension direction of the slits and the stacking direction is three times or more of the dimension in the short direction along the stacking direction of the flow path substrate.

Description

Technical Field

[0001] Embodiments of the present invention relate to a liquid ejection head and a liquid ejection device. Background Art

[0002] In a liquid ejection head such as an inkjet head, the following method is used: an actuator made of a piezoelectric body such as PZT (lead zirconate titanate) is used to deform a vibration plate, thereby deforming a pressure chamber facing the vibration plate, and then ink is ejected from a nozzle communicating with the pressure chamber. The liquid ejection head includes: a plurality of actuators joined to the vibration plate; and a flow path portion that forms a plurality of pressure chambers facing the vibration plate and a flow path having a larger fluid resistance than the pressure chambers communicating with the pressure chambers. In the flow path portion of such an inkjet head, sometimes a plurality of flow path plates having slits with a specified shape are stacked to form the flow path portion. The accuracy of the fluid resistance portion in the flow path portion greatly affects the performance. That is, when the cross-sectional area is large, the meniscus vibration of the nozzle portion after ejection becomes large, and when the cross-sectional area is small, the refill becomes slow, which are both causes that hinder high-speed followability. Particularly in the circulation method in which ink circulates in the pressure chamber, if there is a difference in fluid resistance between the upstream and the downstream, there is a difference in negative pressure in the pressure chamber, and thus it becomes a cause of difference in ejection performance.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-149368 Summary of the Invention

[0004] Technical Problem to be Solved by the Invention

[0005] The technical problem to be solved by the present invention is to provide a liquid ejection head and a liquid ejection device capable of improving the accuracy of fluid resistance.

[0006] Solution for Solving the Technical Problem

[0007] The liquid ejection head according to one embodiment includes a plurality of flow path substrates. The plurality of flow path substrates are formed with openings forming flow paths and are stacked in the stacking direction. At least any one of the flow path substrates has a slit. The flow path formed by the slit has a flow path cross-section, and the dimension in the long side direction orthogonal to the extending direction of the slit and the stacking direction is 3 times or more the dimension in the short side direction along the stacking direction of the flow path substrate. Brief Description of the Drawings

[0008] Figure 1 It is a cross-sectional view showing a partial structure of an inkjet head according to a first embodiment.

[0009] Figure 2 It is a cross-sectional view showing a partial structure of the inkjet head.

[0010] Figure 3It is a cross-sectional view showing a partial structure of the first flow path substrate of the inkjet head.

[0011] Figure 4 It is a cross-sectional view showing a partial structure of the second flow path substrate of the inkjet head.

[0012] Figure 5 It is a table showing the pipe friction coefficient ratio of a rectangular pipe.

[0013] Figure 6 It is a graph showing the relationship between the pipe friction coefficient ratio and the aspect ratio of a rectangular pipe.

[0014] Figure 7 It is a graph showing the correspondence between the aspect ratio of the flow path and the fluid resistance ratio of the inkjet head according to the first embodiment.

[0015] Figure 8 It is an explanatory diagram showing a schematic structure of the inkjet recording apparatus according to the first embodiment.

[0016] Explanation of Reference Numerals

[0017] 1: Inkjet head; 20: Actuator section; 21: Driving piezoelectric element; 22: Non-driving piezoelectric element; 23: Groove section; 26: Piezoelectric structure section; 30: Vibration plate; 31: Pressure chamber; 32: Common chamber; 33: Independent liquid chamber; 34: Throttle flow path (resistance flow path); 35: Ink flow path; 40: Flow path section; 41: Peripheral wall section; 42: Partition section; 43: Side wall section; 45: Frame section; 50: Nozzle plate; 51: Nozzle; 70: Driving circuit; 100: Inkjet recording apparatus; 111: Housing; 112: Medium supply section; 113: Image forming section; 114: Medium discharge section; 115: Conveying device; 117: Support section; 118: Conveyor belt; 119: Support plate; 120: Belt roller; 121: Pair of guide plates; 122: Conveying roller; 130: Head unit; 132: Ink tank; 133: Connecting flow path; 134: Supply pump; 150: Control section; 151: Control circuit; 211: Piezoelectric layer; 221: Internal electrode; 222: Internal electrode; 223: External electrode; 224: External electrode; 301: Vibration region; 302: Support region; 303: Opening; 401: Flow path substrate; 402: Flow path substrate; 403: Flow path substrate; 461, 462, 463: Beam-like sections; 4011: First opening; 4012: Second opening; 4021: First opening; 4022: Second opening; 4023: Slit; 4024: Long hole section; 4031: First opening; 4032: Second opening; 72: Driving IC; d33: Piezoelectric constant. Detailed Embodiments

[0018] Hereinafter, with reference to Figures 1 to 8, the inkjet head 1 as the liquid ejection head according to the first embodiment and the inkjet recording apparatus 100 as the liquid ejection apparatus will be described. Figure 1 is a cross-sectional view showing a partial structure of the inkjet head according to the first embodiment, Figure 2 is a cross-sectional view showing a partial structure of the inkjet head. Figure 3 is a cross-sectional view showing a partial structure of the flow path substrates 401 and 402 of the inkjet head, Figure 4 is a cross-sectional view showing a partial structure of the flow path substrate 403. Figure 5 is a table showing the pipe friction coefficient ratio of a rectangular pipe, Figure 6 is a graph showing the relationship between the pipe friction coefficient ratio of a rectangular pipe and the aspect ratio. Figure 7 is a graph showing the correspondence between the aspect ratio of the flow path of the inkjet head according to the first embodiment and the fluid resistance ratio. Figure 8 is an explanatory view showing a schematic structure of the inkjet recording apparatus. Arrows X, Y, and Z in the figure respectively represent three mutually orthogonal directions. In the present embodiment, X is along the juxtaposed direction of the nozzles 51 and the pressure chambers 31, Y is along the extending direction, and Z is along the axial direction of the nozzles. In each figure, for ease of explanation, the structure is appropriately enlarged, reduced, or omitted for representation.

[0019] As Figure 1 and Figure 2 shown, the inkjet head 1 includes an actuator unit 20, a diaphragm 30, a flow path unit 40 as a flow path unit having a plurality of flow path substrates 401, 402, and 403, a nozzle plate 50 as a nozzle unit having a plurality of nozzles 51, a frame unit 45 as a structural unit, and a drive circuit 70. As an example, in the present embodiment, the inkjet head 1 shows an example in which the stacking direction of the piezoelectric layer 211, the vibration direction of the piezoelectric element 21, and the vibration direction of the diaphragm 30 are respectively along the Z direction. In the present embodiment, on the back side of the nozzle plate 50, a flow path structure unit that forms an ink flow path 35 in the head 1 is constituted by the diaphragm 30 and the flow path unit 40. The inkjet head 1 is a circulation type that circulates liquid in a prescribed flow path.

[0020] The actuator unit 20 is constituted by a piezoelectric member, for example, and includes a plurality of drive piezoelectric elements 21 as actuators, a plurality of non-drive piezoelectric elements 22, and a piezoelectric structure unit 26 that connects the plurality of piezoelectric elements 21 and 22 integrally, which are alternately arranged in the column direction. In the present embodiment, a nozzle 51 is provided at the center in the extending direction of the actuator unit 20, and the actuator unit 20 has a structure that is symmetric on one side and the other side with the nozzle 51 as the center. For example, the actuator unit 20 is joined to a rectangular base. In addition, the plurality of drive piezoelectric elements 21 and non-drive piezoelectric elements 22 of the actuator unit 20 may not be continuous through the piezoelectric structure unit 26 but may be separated from each other.

[0021] In the actuator unit 20, a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 are arranged at regular intervals in the juxtaposition direction. As an example, both the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22 are configured as columnar bodies in the shape of a rectangular parallelepiped with the same shape. The actuator unit 20 is divided into a plurality of parts by a plurality of groove parts 23, and the plurality of driving piezoelectric elements 21 and non-driving piezoelectric elements 22 are arranged at the same pitch in the column direction by the groove parts 23 with the same width, for example. For example, the number of driving piezoelectric elements 21 arranged in the column direction in the actuator unit 20 corresponds to the number of nozzles 51 and pressure chambers 31.

[0022] For example, the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22 are each configured such that, when viewed from above in the Z direction which is the axial direction of the nozzle 51, the short side direction is along the column direction of the element columns and the long side direction is along the extending direction orthogonal to the column direction and the Z direction, in a rectangular shape.

[0023] The driving piezoelectric elements 21 are arranged in the Z direction at positions respectively opposed to the plurality of pressure chambers 31 formed in the flow path unit 40. As an example, the center positions of the column direction and the extending direction of the driving piezoelectric elements 21 are arranged side by side in the Z direction with the center positions of the column direction and the extending direction of the pressure chambers 31.

[0024] The non-driving piezoelectric elements 22 are arranged in the Z direction at positions respectively opposed to the partition parts 42 formed in the flow path unit 40. As an example, the center positions of the column direction and the extending direction of the non-driving piezoelectric elements 22 are arranged side by side in the Z direction with the center positions of the column direction and the extending direction of the partition parts 42.

[0025] For example, the laminated piezoelectric member constituting the actuator unit 20 is formed by laminating and sintering sheet-like piezoelectric materials. In the actuator unit 20, the groove parts 23 are formed by cutting the laminated piezoelectric member from one end face, so as to form a plurality of piezoelectric elements in the shape of rectangular columns at a prescribed interval. Then, electrodes and the like are provided on the plurality of formed columnar elements to form a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 which are alternately arranged. The plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22 are alternately arranged side by side in the column direction with the groove parts 23 therebetween.

[0026] The piezoelectric members constituting the drive piezoelectric element 21 and the non-drive piezoelectric element 22 are, for example, laminated piezoelectric bodies. The drive piezoelectric element 21 and the non-drive piezoelectric element 22 include a plurality of laminated piezoelectric layers 211 and internal electrodes 221 and 222 formed on the main surfaces of the respective piezoelectric layers 211. In addition, as an example, the drive piezoelectric element 21 and the non-drive piezoelectric element 22 have the same laminated structure. Moreover, the drive piezoelectric element 21 and the non-drive piezoelectric element 22 include external electrodes 223 and 224 formed on the surfaces.

[0027] The piezoelectric layer 211 is made of a piezoelectric material such as a PZT (lead zirconate titanate) - based or lead - free KNN (sodium potassium niobate) - based material. The plurality of piezoelectric layers 211 are laminated such that the thickness direction is along the lamination direction. For example, in the present embodiment, the thickness direction and the lamination direction of the piezoelectric layer 211 are arranged along the vibration direction (Z direction).

[0028] The internal electrodes 221 and 222 are conductive films made of a fired - formable conductive material such as silver palladium and formed in a specified shape. The internal electrodes 221 and 222 are formed in specified regions on the main surfaces of the respective piezoelectric layers 211. The internal electrodes 221 and 222 are different poles. For example, one internal electrode 221 is formed in a region that reaches one end of the piezoelectric layer 211 but does not reach the other end of the piezoelectric layer 211 in the extending direction (Y direction), which is orthogonal to both the arrangement direction (column direction, X direction) of the plurality of drive piezoelectric elements 21 and the plurality of non - drive piezoelectric elements 22 and the vibration direction (Z direction). The other internal electrode 222 is formed in a region that does not reach one end of the piezoelectric layer 211 but reaches the other end of the piezoelectric layer 211 in the extending direction. The internal electrodes 221 and 222 are respectively connected to the external electrodes 223 and 224 formed on the sides of the piezoelectric elements 21 and 22.

[0029] In addition, the laminated piezoelectric member constituting the drive piezoelectric element 21 and the non - drive piezoelectric element 22 may further include dummy layers on either or both of the ends on the nozzle plate 50 side or the opposite side. For example, the dummy layer is made of the same material as the piezoelectric layer 211, has an electrode only on one side, and does not have an electric field applied, so it does not deform. For example, the dummy layer does not function as a piezoelectric body but serves as a grinding allowance for fixing the actuator portion 20 to the base or for improving the accuracy during and after assembly.

[0030] External electrodes 223 and 224 are formed on the surfaces of a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22, and are constituted by concentrating the ends of the internal electrodes 221 and 222. For example, the external electrodes 223 and 224 are respectively formed on one end face and the other end face in the extending direction of the piezoelectric body layer 211. In the external electrodes 223 and 224, films are formed by methods such as electroplating and sputtering using Ni, Cr, Au, etc. The external electrode 223 and the external electrode 224 are different poles. The external electrode 223 and the external electrode 224 are respectively disposed on different side faces of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22. In addition, the external electrode 223 and the external electrode 224 may also be arranged in different regions of the same side face of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22.

[0031] In the present embodiment, as an example, the external electrode 223 is set as an independent electrode, and the external electrode 224 is set as a common electrode. The electrode layer of the external electrode 223, which is an independent electrode of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22, is divided by the groove portion 23 and is disposed independently of each other. The electrode layer of the external electrode 224, which is a common electrode, is connected to each other on the side surface of the piezoelectric structure portion 26, for example, and is grounded. The external electrodes 223 and 224 are connected to the driving circuit 70 via a wiring film, for example. For example, each of the external electrodes 223 and 224 is connected to the control unit 150 via the driving IC 72 of the driving circuit 70, and is configured to be capable of driving and controlling. In addition, the arrangement of the common electrode and the independent electrode may be reversed.

[0032] In addition, the vibration directions of the piezoelectric elements 21 and 22 are along the stacking direction, and are displaced in the d33 direction by applying an electric field. The number of stacked layers of the piezoelectric body layers 211 and the internal electrodes 221 and 222 of the piezoelectric elements 21 and 22 is 3 layers or more. As an example, each of the piezoelectric elements 21 and 22 has 3 layers or more and 50 layers or less, the thickness of each layer is 10 μm or more and 40 μm or less, and the product of the thickness and the total number of stacked layers is less than 1000 μm.

[0033] In the inkjet head 1, the driving piezoelectric element 21 vibrates by applying a voltage to the internal electrodes 221 and 222 via the external electrodes 223 and 224. In the present embodiment, the driving piezoelectric element 21 vibrates longitudinally in the stacking direction of the piezoelectric body layer 211. The longitudinal vibration mentioned here is, for example, "vibration in the thickness direction defined by the piezoelectric constant d33". The driving piezoelectric element 21 displaces the vibration plate 30 by longitudinal vibration, and deforms the pressure chamber 31.

[0034] The vibration plate 30 extends along a plane orthogonal to the Z direction which is the vibration direction, and is joined to the side of the piezoelectric body layers 211 of the plurality of piezoelectric elements 21, 22 on the side in the vibration direction, that is, the side facing the nozzle plate 50. The vibration plate 30 faces the plurality of nozzles 51 across the pressure chamber 31 in the Z direction which is the vibration direction. The vibration plate 30 is configured to be deformable, for example. The vibration plate 30 is joined to the drive piezoelectric element 21, the non-drive piezoelectric element 22, and the frame portion 45 of the actuator portion 20. For example, the vibration plate 30 has a vibration region 301 facing the piezoelectric elements 21, 22 and a support region 302 facing the frame portion 45. The vibration plate 30 is provided between the flow path substrate 401 and the actuator portion 20 in the vibration direction. The vibration plate 30 is overlapped and arranged with a plurality of flow path substrates 401, 402, 403 to form a part of the ink flow path 35.

[0035] The vibration region 301 is, for example, a flat plate shape arranged such that the thickness direction becomes the vibration direction of the piezoelectric body layer 211. The plane direction of the vibration plate 30 extends along the arrangement direction of the plurality of drive piezoelectric elements 21 and the plurality of non-drive piezoelectric elements 22. The vibration plate 30 is, for example, a metal plate. The vibration plate 30 has a plurality of vibration parts facing the respective pressure chambers 31 and capable of displacing independently. The vibration plate 30 is formed by connecting the plurality of vibration parts integrally.

[0036] As an example, the vibration plate 30 is made of nickel or a SUS plate, and the thickness dimension in the vibration direction is configured to be about 5 μm to 15 μm. In addition, creases or steps may be formed in the part adjacent to the vibration part or between the vibration parts adjacent to each other in the vibration region 301 so that the plurality of vibration parts are easily displaceable. By the elongation and compression of the drive piezoelectric element 21, the part arranged opposite to the drive piezoelectric element 21 is displaced, thereby deforming the vibration region 301. For example, since the vibration plate 30 needs to be very thin and have a complex shape, it is formed by electroforming or the like. The vibration plate 30 is joined to the upper end surface of the actuator portion 20 by adhesion or the like.

[0037] The support region 302 is a plate-like member arranged between the frame portion 45 and the flow path substrate 401. The vibration plate 30 has a structure symmetric with respect to one side and the other side in the Y direction with the nozzle 51 as the center.

[0038] The flow path portion 40 is joined to one side of the vibration plate 30.

[0039] The flow path section 40 includes a plurality of stacked flat flow path substrates 401, 402, and 403. As an example, the flow path section 40 includes, in a stacked manner, a flow path substrate 401 and a flow path substrate 402, which are configured in the same shape and serve as the first flow path substrates, and a flow path substrate 403 that serves as the second flow path substrate. For example, according to the viscosity of the ink, the ejected volume, etc., a plurality of flow path substrates 401, 402, 403, a nozzle plate 50, and a vibration plate 30 are combined and joined to form a desired ink flow path 35. The plurality of flow path substrates 401, 402, 403 are overlapped and arranged in the stacking direction, and a predetermined ink flow path 35 is formed through the openings and grooves formed in each of the flow path substrates 401, 402, 403. The ink flow path 35 includes a plurality of pressure chambers 31 communicating with a plurality of nozzles 51, a plurality of throttle flow paths 34 serving as independent flow paths, and independent liquid chambers 33 communicating with a common chamber 32.

[0040] The flow path section 40 is disposed between the nozzle plate 50 and the vibration plate 30. In the flow path section 40, a predetermined ink flow path 35 (liquid chamber) is formed inside by stacking and joining a plurality of flow path substrates 401, 402, 403. The ink flow path 35 has a plurality of pressure chambers 31, a plurality of independent liquid chambers 33 communicating with a common chamber 32, and throttle flow paths 34 serving as a plurality of resistance flow paths from the independent liquid chambers 33 to the pressure chambers 31. In other words, in the flow path section 40, a peripheral wall portion 41 surrounding the ink flow path 35 (liquid chamber) formed by the plurality of pressure chambers 31, the plurality of throttle flow paths 34, and the independent liquid chambers 33, a plurality of partition portions 42 separating the column intervals of the plurality of pressure chambers 31, and side wall portions 43 separating the plurality of throttle flow paths 34 are formed by using the stacked plurality of flow path substrates 401, 402, 403.

[0041] As Figures 1 to 4 shown, the flow path substrate 401 serving as the first flow path substrate is joined to the vibration plate 30. The flow path substrate 401 is a plate-shaped member having the same shape as the vibration plate 30. As an example, it is made of a metal material containing SUS430 or a resin material such as silicon. In addition, in Figure 3 and Figure 4 , regions of three columns in the ink flow path 35 formed in multiple columns in the parallel direction are shown.

[0042] The flow path substrate 401 has a first opening 4011 that forms part of the pressure chamber 31 and a second opening 4012 that forms part of the independent liquid chamber 33. For example, the first opening 4011 is disposed at the center in the extending direction of the ink flow path 35, and the second openings 4012 are disposed at both ends respectively. In the arrangement direction, the openings 4011 and 4012 are arranged in multiple columns corresponding to the number of nozzles 51 arranged, a beam-shaped portion 461 is formed between the adjacent openings 4011 in the arrangement direction, and a beam-shaped portion 462 is formed between the adjacent openings 4012 in the arrangement direction. The beam-shaped portions 461 and 462 have the same length as the lengths of the openings 4011 and 4012 respectively.

[0043] The flow path substrate 402 as the second flow path substrate is laminated on the flow path substrate 401 and joined to the flow path substrate 401. The flow path substrate 402 is a plate-shaped member having the same shape as the diaphragm 30. As an example, it is made of a metal material containing SUS430 or a resin material such as silicon. The flow path substrate 402 has an elongated long hole portion 4024, and the long hole portion 4024 integrally has a first opening 4021 that forms part of the pressure chamber 31, a second opening 4022 that forms part of the independent liquid chamber 33, and a slit 4023 that connects the first opening 4021 and the second opening 4022 to form a throttling flow path 34 as an independent flow path. For example, the first opening 4021 is disposed at the center in the extending direction of the ink flow path 35, and the second openings 4022 are disposed at both ends respectively. They are continuous through the slit 4023 to form an elongated groove-shaped long hole portion 4024.

[0044] The long hole portions 4024 are arranged in multiple columns in the arrangement direction, and a beam-shaped portion 463 is formed between the adjacent long hole portions 4024 in the arrangement direction. The length of the beam-shaped portion 463 is the same as the length of the long hole portion 4024.

[0045] That is, the flow path substrate 402 has a long hole portion 4024 with a longer length of the opening in the extending direction compared to the flow path substrates 401 and 403 as other flow path substrates. For example, the long hole portion 4024 of the flow path substrate 402 is a slit that spans the entire length of the ink flow path 35 in one direction and extends from one end to the other end of the ink flow path 35 in the extending direction (Y direction).

[0046] The thickness dimension HA of the second flow path substrate 402 is 1 / 3 or less of the width dimension WA of the slit 4023 formed in the second flow path substrate 402. Further, in the present embodiment, the flow path cross section of the throttle flow path 34 orthogonal to the extending direction of the flow direction is configured such that the width direction of the slit 4023 is longer than the thickness direction. Thus, the long side direction of the flow path cross section of the throttle flow path 34 is the width direction of the slit 4023, and the short side direction of the flow path cross section is the thickness direction of the substrate 402. In the present embodiment, the dimension WA in the width direction of the slit 4023, which is a part of the opening formed in the second flow path substrate 402, i.e., the long side direction of the flow path cross section of the slit 4023, is 3 times or more the thickness dimension HA of the flow path substrate 402 in the short side direction of the flow path cross section.

[0047] For example, the second flow path substrate 402 is configured to have a thickness of 20 μm to 100 μm. For example, in the case of 300 dpi, the pitch of the arrangement of the pressure chambers 31 in the juxtaposed direction is 169 μm, the width of the pressure chamber 31 is about 100 μm to 150 μm, and for example, the width of the beam-like portion 463 is about 20 μm to 70 μm.

[0048] The flow path substrate 403 serving as the first flow path substrate is joined to the flow path substrate 402. The flow path substrate 403 is a plate-like member having the same shape as the flow path substrate 401 and is made of, for example, a metal material containing SUS430 or a resin material such as silicon. The flow path substrate 403 has a first opening 4031 forming a part of the pressure chamber 31 and a second opening 4032 constituting a part of the independent liquid chamber 33. For example, the first opening 4031 is disposed at the center in the extending direction in which the ink flow path 35 extends, and the second openings 4032 are disposed at both ends, respectively. In the arrangement direction, a plurality of each of the openings 4031 and 4032 are arranged, and a beam-like portion 461 is formed between the openings 4021 adjacent in the arrangement direction, and a beam-like portion 462 is formed between the openings 4012 adjacent in the arrangement direction. The beam-like portions 461 and 462 have lengths that are the same as the lengths of the openings 4021 and 4022, respectively, in the long side direction.

[0049] For example, the flow path substrates 401 and 403 serving as the first flow path substrate are configured to have a thickness of 20 μm to 100 μm. For example, in the case of 300 dpi, the pitch of the arrangement of the pressure chambers 31 in the juxtaposed direction is 169 μm, the width of the pressure chamber 31 is about 100 μm to 150 μm, and the width of the beam-like portion 461 is about 20 μm to 70 μm.

[0050] For example, the flow path substrates 401, 402, and 403 are formed by forming openings at specified positions in a metal plate made of SUS or the like and processed to a specified thickness by etching treatment.

[0051] In the flow path section 40, a plurality of pressure chambers 31 are formed by the first opening portions 4011, 4021, 4031 of a plurality of flow path base plates 401, 402, 403 that are connected in parallel in the stacking direction. The plurality of pressure chambers 31 are spaces formed on one side of the vibration region 301 of the vibration plate 30, and each pressure chamber 31 communicates with a nozzle 51 formed in a nozzle plate 50 (nozzle member). In addition, the side of the nozzle plate 50 opposite to the pressure chamber 31 is blocked by the vibration plate 30.

[0052] The plurality of pressure chambers 31 communicate with the common chamber 32 via the throttle flow paths 34 and the independent liquid chambers 33 and through the opening portion 303. The pressure chambers 31 hold the liquid supplied from the common chamber 32, and are deformed by the vibration of the vibration plate 30 that forms a part of the pressure chamber 31, so that the liquid is ejected from the nozzle 51.

[0053] In the flow path section 40, independent liquid chambers 33 on both sides in the Y direction of the pressure chamber are formed by the second opening portions 4012, 4022, 4032 of a plurality of flow path base plates 401, 402, 403 that are connected in parallel in the stacking direction.

[0054] The independent liquid chambers 33 are flow paths that communicate with the ends in the flow direction of the plurality of throttle flow paths 34. The independent liquid chambers 33 are formed, for example, between the vibration plate 30 and the nozzle plate 50, and communicate with the common chamber 32 of the frame portion 45. Here, each of the flow path base plates 401, 402, 403 has a structure that is symmetric on one side and the other side in the Y direction with the nozzle 51 as the center, and is configured such that the flow path lengths of the independent liquid chambers 33 arranged on both sides in the Y direction and the cross-sectional shape of the flow path orthogonal to the Y direction are equal with the central pressure chamber 31 as the center.

[0055] In addition, in the flow path section 40, the throttle flow paths 34 are formed by the slits 4023. The throttle flow paths 34 communicate the pressure chambers 31 and the independent liquid chambers 33 and extend along the Y direction that becomes the flow direction. The throttle flow paths 34 on both sides have a smaller dimension in the width direction orthogonal to the extension direction of the flow direction compared to the independent liquid chambers 33 and the pressure chambers 31, and the cross-sectional shape of the flow path is narrower. That is, the throttle flow paths 34 are narrow portions where the flow path is reduced in the width direction that intersects the stacking direction and the extension direction of the flow path.

[0056] Here, each of the flow path base plates 401, 402, 403 has a structure that is symmetric on one side and the other side in the Y direction with the nozzle 51 as the center, and is configured such that the flow path lengths of the throttle flow paths 34 arranged on both sides in the Y direction and the cross-sectional shape of the flow path orthogonal to the Y direction are equal with the central pressure chamber 31 as the center. In addition, in the flow path section 40, a partition portion 42 that separates the plurality of pressure chambers 31 is formed by using the central portions of the beam-like portions 461 of the stacked flow path base plates 401, 402 and the beam-like portion 463 of the flow path base plate 403.

[0057] The partition portion 42 is a wall-like member that separates between the plurality of pressure chambers 31 in the arrangement direction. The partition portion 42 is disposed opposite to the non-driven piezoelectric element 22 with the diaphragm 30 interposed therebetween, and is supported by the non-driven piezoelectric element 22. A plurality of partition portions 42 are provided at the same pitch as the pitch at which the plurality of pressure chambers 31 are arranged side by side.

[0058] In the flow path portion 40, a side wall portion 43 that separates between the plurality of throttle flow paths 34 is formed by a portion between the slits 4023 of the beam-like portion 463 of the flow path substrate 403.

[0059] The side wall portion 43 is a wall-like member that separates between the plurality of throttle flow paths 34 in the arrangement direction. For example, the side wall portion 43 is provided at the inlet of the pressure chamber 31. The side wall portion 43 is configured such that the flow path resistance of the throttle flow path 34 is larger than that inside the pressure chamber 31, and the flow path cross-sectional area of the throttle flow path 34 is smaller than that inside the pressure chamber 31. A plurality of side wall portions 43 are provided at the same pitch as the pitch at which the plurality of pressure chambers 31 are arranged side by side.

[0060] That is, in the flow path portion 40, a space that is sandwiched by the flow path substrate 401 and the flow path substrate 403 in the stacking direction and is sandwiched by the side wall portions 43, 43 in the width direction, that is, the throttle flow path 34 in the extending direction is formed. The dimension in the short side direction of the flow path cross section, which is the cross section of the throttle flow path 34 orthogonal to the extending direction, is the dimension between the flow path substrate 401 and the flow path substrate 403, that is, the thickness dimension HA of the flow path substrate 402, and the dimension in the long side direction is the dimension in the width direction of the slit 4023.

[0061] Therefore, on both sides of the pressure chamber 31, the throttle flow path 34 in the extending direction has a rectangular flow path cross section in which the dimension in the long side direction along the width direction of the slit 4023 is more than 3 times the dimension in the short side direction along the thickness direction of the flow path substrate 402.

[0062] Figure 5 It is a table showing the relationship between the pipe friction coefficient ratio k of a rectangular pipe and the aspect ratio (based on the technical data of the Japan Society of Mechanical Engineers "Fluid Resistance of Pipes / Tubes"). Figure 6 It is a graph showing the relationship between the pipe friction coefficient ratio k of a rectangular pipe and the aspect ratio. The horizontal axis is the aspect ratio ε, and the vertical axis is the pipe friction coefficient ratio k.

[0063] As Figure 5 shown, in a flow path having a rectangular cross section, when the Reynolds number is small and the pipe length L is sufficiently long (for example, more than one digit longer than the side length of the cross section), the viscosity of the ink is set to μ (Pa·s), and the cross-sectional area is A (m 2), the flow path resistance R of a pipe with a wetting edge length S (m) and a pipe length L (m) is expressed by R (Pa·s / m^3) = 2k(S^2 / A^3)·L·μ (Equation 1).

[0064] At this time, k is the pipe friction coefficient ratio of a rectangular pipe. As Figure 5 and Figure 6 shown, it increases sharply when the aspect ratio is less than 0.3. The pipe length L is the length in the extending direction of the flow path.

[0065] Figure 7 is a table comparing the magnitudes of fluid resistances by substituting values of ±10% for the long side of the flow path cross-section orthogonal to the extending direction of the throttle flow path 34 as the fluid resistance portion to be 100 μm and the short side to be 30 μm. In addition, in order to obtain the fluid resistance ratio, instead of m, μm is directly substituted, and k is calculated from the approximate formula of the chart. L and μ are the same.

[0066] According to Figure 7 , the change in the resistance value due to a 3-μm change in the short side is greater than the change in the resistance value due to a 10-μm change in the long side. That is, in Figure 7 , it can be seen that when the short side is fixed at 30 μm and the long side length changes by 10 μm each time in the upper three columns of the table, and when the long side length is fixed and the short side length changes by 3 μm each time in the lower two columns of the table, the change in fluid resistance is greater when the short side length changes. Therefore, regarding the fluid resistance value, the precision of the short side is dominant, and it can be said that improving the precision of the short side is related to improving the precision of the fluid resistance.

[0067] For example, the flow path substrate 402 is formed by forming openings on a thin metal plate such as a SUS plate by etching or the like. Although it also depends on the method and cost, generally the plate thickness precision is higher than the etching precision. Therefore, the fluid resistance precision is improved by setting the plate thickness as the short side and the etched opening as the long side. Especially when the viscosity of the ink is smaller, the proportion of factors other than the ink viscosity in the fluid resistance is larger, so the precision of the flow path shape becomes important.

[0068] The nozzle plate 50 is configured, for example, as a square plate-like shape with a thickness of about 10 μm to 100 μm made of a metal such as SUS or Ni, or a resin material such as polyimide. The nozzle plate 50 is arranged on one side of the flow path portion 40 so as to cover the opening on one side of the pressure chamber 31. The nozzle plate 50 has a plurality of nozzles 51 for ejecting droplets. The plurality of nozzles 51 are hole portions that penetrate the nozzle plate 50 in the thickness direction. The nozzles 51 are arranged in parallel in a first direction that is the same as the arrangement direction of the pressure chambers 31 to form a nozzle row. Each nozzle 51 is provided at a position corresponding to the plurality of pressure chambers 31.

[0069] The frame portion 45 is a structure joined to the piezoelectric elements 21 and 22 together with the diaphragm 30. The frame portion 45 is provided on the side of the piezoelectric elements 21 and 22 opposite to the flow path portion 40 of the diaphragm 30, and is arranged adjacent to the actuator portion 20 in this embodiment, for example. The frame portion 45 forms the outer contour of the inkjet head 1. In addition, the frame portion 45 may form a flow path for the liquid inside. In this embodiment, the frame portion 45 is joined to the other side of the diaphragm 30, and a common chamber 32 is formed between the frame portion 45 and the diaphragm 30.

[0070] The common chamber 32 is formed inside the frame portion 45 and communicates with the pressure chamber 31 through the opening 303 provided in the diaphragm 30, the individual liquid chambers 33, and the throttle flow path 34.

[0071] The drive circuit 70 includes a wiring film having one end connected to the external electrodes 223 and 224, a driver IC mounted on the wiring film, and a printed wiring board mounted on the other end of the wiring film.

[0072] The drive circuit 70 applies a drive voltage to the external electrodes 223 and 224 using the driver IC, thereby driving the piezoelectric element 21, increasing and decreasing the volume of the pressure chamber 31, and ejecting droplets from the nozzle 51.

[0073] The wiring film is connected to the plurality of external electrodes 223 and 224. For example, the wiring film is an ACF (anisotropic conductive film) fixed to the connection portions of the external electrodes 223 and 224 by thermocompression bonding or the like. The wiring film is, for example, a COF (Chip on Film) on which the driver IC is mounted.

[0074] The driver IC is connected to the external electrodes 223 and 224 via the wiring film. In addition, the driver IC may be connected to the external electrodes 223 and 224 by other means such as ACP (anisotropic conductive paste), NCF (non-conductive film), and NCP (non-conductive paste) without passing through the wiring film.

[0075] The drive IC generates a control signal and a drive signal for operating each piezoelectric element 21. The drive IC generates a control signal for controlling the timing of ejecting ink and the piezoelectric element 21 for ejecting ink, etc., in accordance with the image signal input from the control unit 150 of the inkjet recording apparatus 100. Further, the drive IC generates a voltage applied to the piezoelectric element 21, i.e., a drive signal (electrical signal), in accordance with the control signal. When the drive IC applies the drive signal to the piezoelectric element 21, the piezoelectric element 21 drives the diaphragm 30 to displace and change the volume of the pressure chamber 31. As a result, pressure vibration is generated in the ink filled in the pressure chamber 31. The ink is ejected from the nozzle 51 provided in the pressure chamber 31 by the pressure vibration. In addition, the inkjet head 1 can also achieve gradation expression by changing the amount of ink droplets landing on one pixel. Further, the inkjet head 1 can also change the amount of ink droplets landing on one pixel by changing the number of times of ink ejection. In this way, the drive IC is an example of an application unit that applies the drive signal to the piezoelectric element 21.

[0076] For example, the drive IC includes a data buffer, a decoder, and a driver. The data buffer stores print data in time series for each piezoelectric element 21. The decoder controls the driver based on the print data stored in the data buffer for each piezoelectric element 21. The driver outputs a drive signal for operating each piezoelectric element 21 based on the control of the decoder. The drive signal is, for example, a voltage applied to each piezoelectric element 21.

[0077] The printed wiring board is a PWA (Printing Wiring Assembly) on which various electronic components and connectors are mounted. The printed wiring board is connected to the control unit 150 of the inkjet recording apparatus 100.

[0078] In the inkjet head 1 configured as described above, an ink flow path 35 having a plurality of pressure chambers 31 communicating with the nozzle 51, an independent flow path composed of throttle flow paths 34 communicating with the plurality of pressure chambers 31, and an independent liquid chamber 33 and a common chamber 32 serving as a common flow path is formed by the nozzle plate 50, the frame portion 45, the flow path portion 40, and the diaphragm 30. For example, the common chamber 32 communicates with the cartridge, and ink is supplied to each pressure chamber 31 through the common chamber 32. All the piezoelectric elements 21 are connected so that a voltage can be applied through wiring. In the inkjet head 1, when the control unit 150 applies a drive voltage to the electrodes 221 and 222 through the drive IC, the piezoelectric element 21 to be driven vibrates in the stacking direction, i.e., the thickness direction of each piezoelectric body layer 211. That is, the piezoelectric element 21 performs longitudinal vibration.

[0079] Specifically, the control unit 150 applies a driving voltage to the internal electrodes 221 and 222 of the piezoelectric element 21 to be driven, and selectively drives the piezoelectric element 21 to be driven. Then, the diaphragm 30 is deformed by combining the deformation in the stretching direction and the deformation in the compression direction caused by the piezoelectric element 21 to be driven, and the volume of the pressure chamber 31 is changed, so that the liquid is guided from the common chamber 32 and ejected from the nozzle 51.

[0080] Hereinafter, with reference to Figure 8 An example of an inkjet recording apparatus 100 including an inkjet head 1 will be described. The inkjet recording apparatus 100 includes a housing 111, a medium supply unit 112, an image forming unit 113, a medium discharge unit 114, a conveying device 115, and a control unit 150.

[0081] The inkjet recording apparatus 100 is a liquid ejection apparatus that ejects a liquid such as ink while conveying a printing medium such as a paper P as an ejection object along a predetermined conveyance path RA that passes from the medium supply unit 112 through the image forming unit 113 to the medium discharge unit 114, thereby performing an image forming process on the paper P.

[0082] The housing 111 forms the outer contour of the inkjet recording apparatus 100. A discharge port for discharging the paper P to the outside is provided at a predetermined position of the housing 111.

[0083] The medium supply unit 112 includes a plurality of paper feed cassettes and is configured to be able to stack and hold a plurality of sheets of paper P of various sizes.

[0084] The medium discharge unit 114 includes a paper discharge tray configured to be able to hold the paper P discharged from the discharge port.

[0085] The image forming unit 113 includes a support unit 117 that supports the paper P and a plurality of head units 130 that are disposed opposite each other above the support unit 117.

[0086] The support unit 117 includes a conveyor belt 118 that is annularly provided in a predetermined area where image formation is performed, a support plate 119 that supports the conveyor belt 118 from the back side, and a plurality of belt rollers 120 that are provided on the back side of the conveyor belt 118.

[0087] During image formation, the support unit 117 supports the paper P on a holding surface that is the upper surface of the conveyor belt 118, and conveys the conveyor belt 118 at a predetermined timing by the rotation of the belt rollers 120, thereby conveying the paper P toward the downstream side.

[0088] The head unit 130 includes a plurality of (4-color) inkjet heads 1, ink tanks 132 as liquid tanks respectively mounted on each inkjet head 1, connection flow paths 133 that connect the inkjet heads 1 and the ink tanks 132, and supply pumps 134.

[0089] In the present embodiment, an inkjet head 1 having four colors of cyan, magenta, yellow, and black, and ink tanks 132 respectively accommodating inks of the above various colors are provided. The ink tanks 132 are connected to the inkjet head 1 through connection flow paths 133.

[0090] In addition, a negative pressure control device such as a pump (not shown) is connected to the ink tank 132. Moreover, the inside of the ink tank 132 is subjected to negative pressure control by the negative pressure control device corresponding to the head values of the inkjet head 1 and the ink tank 132, so that the ink supplied to each nozzle 51 of the inkjet head 1 forms a meniscus of a specified shape.

[0091] The supply pump 134 is, for example, a liquid feeding pump constituted by a piezoelectric pump. The supply pump 134 is provided in a supply flow path. The supply pump 134 is connected to a drive circuit of the control unit 150 through wiring, and is configured to be controllable by the control of a CPU (Central Processing Unit). The supply pump 134 supplies liquid to the inkjet head 1.

[0092] The conveying device 115 conveys a sheet P along a conveyance path RA that extends from a medium supply unit 112 through an image forming unit 113 to a medium discharge unit 114. The conveying device 115 includes a plurality of guide plate pairs 121 and a plurality of conveying rollers 122 that are arranged along the conveyance path RA.

[0093] Each of the plurality of guide plate pairs 121 includes a pair of plate members that are disposed opposite to each other with the sheet P to be conveyed therebetween, and guides the sheet P along the conveyance path RA.

[0094] The conveying rollers 122 are driven to rotate by the control of the control unit 150, and thereby convey the sheet P downstream along the conveyance path RA. In addition, sensors for detecting the conveyance state of the sheet are arranged at various positions on the conveyance path RA.

[0095] The control unit 150 includes a control circuit 151 such as a CPU serving as a controller, a ROM (ReadOnly Memory) that stores various programs and the like, a RAM (Random Access Memory) that temporarily stores various variable data, image data, etc., and an interface unit that inputs data from the outside and outputs data to the outside.

[0096] In the inkjet recording apparatus 100 configured as described above, for example, when a print instruction based on an operation of the operation input unit is detected at the interface, the control unit 150 drives the conveyance device 115 to convey the paper P, and outputs a print signal to the head unit 130 at a predetermined timing, thereby driving the inkjet head 1. As the ejection operation of the inkjet head 1, a drive signal is supplied to the driver IC according to an image signal corresponding to the image data, a drive voltage is applied to the internal electrodes 221 and 222, and the piezoelectric element 21 to be ejected is selectively driven to vibrate longitudinally in the stacking direction, changing the volume of the pressure chamber 31, so that ink is ejected from the nozzle 51 to form an image on the paper P held on the conveyor belt 118. Further, as the liquid ejection operation, the control unit 150 supplies ink from the ink tank 132 to the common chamber 32 of the inkjet head 1 by driving the supply pump 134.

[0097] Here, the drive operation for driving the inkjet head 1 will be described. The inkjet head 1 according to the present embodiment includes piezoelectric elements 21 disposed opposite to the pressure chambers 31, and these piezoelectric elements 21 are connected so that a voltage can be applied through wiring. The control unit 150 supplies a drive signal to the driver IC according to an image signal corresponding to the image data, applies a drive voltage to the internal electrodes 221 and 222 of the piezoelectric element 21 to be driven, and selectively deforms the piezoelectric element 21 to be driven. Then, by combining the deformation in the stretching direction and the deformation in the compression direction of the diaphragm 30, the volume of the pressure chamber 31 is changed, so that the liquid is ejected.

[0098] For example, the control unit 150 alternately performs a stretching action and a compression action. When stretching is performed in the inkjet head 1 to increase the internal volume of the target pressure chamber 31, the piezoelectric element 21 to be driven contracts, so that the drive piezoelectric elements outside the drive target do not deform. Further, when compression is performed in the inkjet head 1 to decrease the internal volume of the target pressure chamber 31, the piezoelectric element 21 to be driven of the target elongates, so that the non-driven piezoelectric element 22 does not deform.

[0099] According to the inkjet head 1 and the inkjet recording apparatus 100 according to the above-described embodiment, it is possible to improve the accuracy of fluid resistance and suppress variations in ejection performance of each nozzle of the inkjet head. In the inkjet head 1 according to the above-described embodiment, on both sides of the pressure chamber 31, the throttle flow path 34 in the extending direction has a flow path cross-section in which the dimension in the long side direction of the flow path cross-section in the width direction of the slit 4023 is three times or more the dimension in the short side direction of the flow path cross-section in the thickness direction of the flow path substrate 402. That is, as the flow path substrate 402, in the case where the thickness dimension is defined by machining a metal such as SUS and openings are formed by etching, since it is generally easier to ensure higher dimensional accuracy by the method of machining accuracy of the plate thickness than the etching accuracy, the plate thickness direction in which it is easy to ensure dimensional accuracy is set as the short side of the flow path cross-section, the opening width direction in which it is difficult to ensure dimensional accuracy is set as the long side of the flow path cross-section, and the aspect ratio is set to three times or more, so that it is easy to ensure dimensional accuracy and the accuracy of fluid resistance can be improved. Therefore, variations in ejection performance of each nozzle of the inkjet head can be suppressed. In particular, the smaller the viscosity of the ink, the greater the proportion of factors other than the ink viscosity in the fluid resistance, so the accuracy of the flow path shape becomes important. However, according to the above-described embodiment, by ensuring the accuracy of the flow path shape, the ejection performance can be improved.

[0100] In addition, the present invention is not limited to the above-described embodiment, and constituent elements can be deformed and embodied within the scope not departing from the gist thereof at the implementation stage.

[0101] For example, the specific structure of the flow path portion 40 is not limited to the above structure. For example, an example in which the flow path portion 40 is formed by three flow path substrates 401, 402, and 403 is shown, but it may also be two or four or more. In addition, the shape of the opening portions in each of the flow path substrates 401, 402, and 403 is not limited to the above-described embodiment.

[0102] In addition, for example, in the above-described embodiment, an example is shown in which the second opening portions 4012, 4022, and 4032 are divided into a plurality in the column direction and constitute a plurality of independent liquid chambers 33 connected by the common chamber 32, but it is not limited thereto. For example, a plurality of second opening portions 4012, 4022, and 4032 may be continuous in the arrangement direction to constitute a common flow path.

[0103] In addition, the positions in the stacking direction of the first flow path substrates 401 and 403 and the second flow path substrate 402 and the shapes of the respective openings are not limited to the above-described embodiment and can be appropriately changed. For example, the flow path substrates 401 and 403 as the first flow path substrates may be on the nozzle plate 50 side, and the flow path substrate 402 as the second flow path substrate may be on the actuator portion 20 side.

[0104] For example, in the above-described embodiment, the multilayer piezoelectric member is configured to be stacked, and the longitudinal vibration (d33) in the stacking direction is used to drive the piezoelectric element 21, but it is not limited thereto. For example, a method in which the piezoelectric element 21 is composed of a single-layer piezoelectric member can also be applied, and a method of driving by lateral vibration (d31) can also be applied.

[0105] In addition, the specific structures of the piezoelectric elements 21 and 22, the shape of the flow path, and the structures and positional relationships of various elements including the flow path portion 40, the nozzle plate 50, and the frame portion 45 are not limited to the above examples and can be appropriately changed. In addition, the arrangement of the nozzles 51 and the pressure chambers 31 is not limited to the above. For example, two or more rows of nozzles 51 can be arranged. In addition, a dummy chamber can be formed between the plurality of pressure chambers 31.

[0106] In addition, the ejected liquid is not limited to the ink for printing. For example, it can also be a device that ejects a liquid containing conductive particles for forming a wiring pattern of a printed wiring board.

[0107] In addition, in the above-described embodiment, an example in which the inkjet head 1 is used in a liquid ejection device such as an inkjet recording device is shown, but it is not limited thereto. For example, it can also be used in a 3D printer, an industrial manufacturing machine, and a medical use, and can achieve miniaturization, light weight, and low cost.

[0108] According to at least one of the embodiments described above, the accuracy of the fluid resistance can be improved, and the deviation of the ejection performance of each nozzle of the inkjet head can be suppressed.

[0109] Furthermore, several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalents.

Claims

1. A liquid ejection head, characterized in that, Comprising: A plurality of flow path substrates, openings for forming flow paths are formed in the plurality of flow path substrates, and they are stacked in the stacking direction. At least any one of the flow path substrates has a slit, the flow path formed by the slit has a flow path cross section, and the dimension of the flow path cross section in the long side direction orthogonal to the extending direction of the slit and the stacking direction is 3 times or more the dimension in the short side direction along the stacking direction.

2. The liquid ejection head according to claim 1, wherein By communicating the plurality of openings formed in the plurality of flow path substrates, a plurality of pressure chambers, a plurality of resistance flow paths, and a common chamber communicating with the plurality of resistance flow paths are formed. Each of the plurality of resistance flow paths communicates with a corresponding one of the plurality of pressure chambers and has a cross section smaller than that of the pressure chamber in a direction orthogonal to the one direction. The slit constitutes the resistance flow path.

3. The liquid ejection head according to claim 1, wherein The flow path substrate is made of metal.

4. The liquid ejection head according to claim 2, wherein The liquid ejection head comprises: A nozzle member having a plurality of nozzles in the arrangement direction; A flow path portion disposed opposite to one side of the nozzle member in the stacking direction, formed by stacking a plurality of the flow path substrates, and having a plurality of the pressure chambers and the resistance flow paths in the arrangement direction; A plurality of vibration portions disposed opposite to one side of the pressure chamber in the stacking direction; And An actuator portion disposed opposite to one side of the vibration portion in the stacking direction and having a plurality of actuators.

5. A liquid ejection device, characterized in that, Comprising: The liquid ejection head according to any one of claims 1 to 4.

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