Liquid ejection head and liquid ejection device

Abstract

The present invention provides a liquid ejection head and a liquid ejection device that prevent bubbles from being retained at partitions formed between connecting flow channels connected to multiple pressure chambers and maintain ejection efficiency. The liquid ejection head comprises: a nozzle array formed by a plurality of nozzles ejecting liquid arranged in a first direction; a nozzle flow channel connected to the nozzles and extending in a second direction intersecting the first direction; a first pressure chamber; a second pressure chamber adjacent to the first pressure chamber in the first direction; a first connecting flow channel that connects the first pressure chamber and the nozzle flow channel and extends in a third direction orthogonal to both the first and second directions; and a second connecting flow channel that connects the second pressure chamber and the nozzle flow channel and extends in the third direction, wherein, when viewed from the second direction, an inner wall surface of the first connecting flow channel on the second connecting flow channel side includes a first inclined surface extending in a fourth direction intersecting both the first and third directions.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device having the liquid ejection head. Background Art

[0002] Conventionally, a liquid ejection head is known that applies pressure to a pressure chamber by driving a piezoelectric element or the like, thereby ejecting liquid in the pressure chamber from a nozzle. Patent Document 1 discloses a liquid ejection head in which two pressure chambers arranged in a direction intersecting the direction in which the nozzles are arranged are connected to a single nozzle.

[0003] Unlike Patent Document 1, in the case where the liquid ejection head is structured so that a plurality of pressure chambers arranged side by side in the nozzle arrangement direction are connected to one nozzle, the situation in which the ejection efficiency is reduced due to the retention of bubbles at the partition walls formed between the connecting flow channels connected to the plurality of pressure chambers is taken into consideration.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-103418 Summary of the Invention

[0005] The liquid ejection head includes: a nozzle array formed by arranging a plurality of nozzles for ejecting liquid in a first direction; a nozzle flow channel connected to a predetermined nozzle among the plurality of nozzles and extending in a second direction intersecting the first direction; a first pressure chamber that applies pressure to the liquid; a second pressure chamber that applies pressure to the liquid and is adjacent to the first pressure chamber in the first direction; a first connecting flow channel that connects the first pressure chamber and the nozzle flow channel and extends in a third direction orthogonal to both the first direction and the second direction; a second connecting flow channel that connects the second pressure chamber and the nozzle flow channel and extends in the third direction, and when viewed from the second direction, the inner wall surface of the first connecting flow channel located on the second connecting flow channel side includes a first inclined surface extending in a fourth direction intersecting both the first direction and the third direction.

[0006] A liquid ejecting device includes: the liquid ejecting head described above; and a control unit that controls the ejecting operation from the liquid ejecting head. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is an explanatory diagram showing the structure of the liquid ejecting device according to the first embodiment.

[0008] Figure 2 This is an exploded perspective view of the liquid ejection head.

[0009] Figure 3 It is a schematic perspective view of the flow passage formed in the communicating plate as viewed from an oblique direction.

[0010] Figure 4 This is an illustration of the flow path and circulation mechanism of the liquid ejection device.

[0011] Figure 5 for Figure 4 Cross-sectional view along line AA.

[0012] Figure 6 This is an enlarged cross-sectional view of the vicinity of the piezoelectric element.

[0013] Figure 7 for Figure 4 Cross-sectional view of line BB in.

[0014] Figure 8 for Figure 4 Cross-sectional view of line CC in .

[0015] Figure 9 for Figure 4 Cross-sectional view of line DD in FIG.

[0016] Figure 10 It is an enlarged cross-sectional view showing the protective film at the partition wall.

[0017] Figure 11 It is a cross-sectional view showing a partition wall according to the second embodiment.

[0018] Figure 12 It is a cross-sectional view showing a partition wall according to the third embodiment.

[0019] Figure 13 It is a cross-sectional view showing a nozzle flow path according to a fourth embodiment. DETAILED DESCRIPTION

[0020] The following describes embodiments of the present invention with reference to the accompanying drawings. However, the dimensions and scales of the various components in the drawings may differ from the actual dimensions and scales as appropriate. Furthermore, the embodiments described below are preferred specific examples, with various technically preferred limitations being added. However, unless otherwise specified in the following description, the scope of the present invention is not limited to these embodiments.

[0021] 1. First Implementation

[0022] Below, refer to Figure 1 , the liquid ejection device 100 according to the first embodiment will be described.

[0023] Figure 1 It is an explanatory diagram showing the structure of the liquid ejecting device 100 according to this embodiment.

[0024] The liquid ejecting device 100 of this embodiment is an inkjet printing device that ejects ink as liquid onto a medium P. Although the medium P is printing paper, any printing target such as a resin film or cloth can be used as the medium P.

[0025] like Figure 1 As shown, the liquid ejecting device 100 includes a liquid container 93 for storing ink. The liquid container 93 may be, for example, a cartridge that is attachable to and detachable from the liquid ejecting device 100, a bag-shaped ink bag formed of a flexible film, or an ink tank capable of refilling ink. The liquid container 93 stores a plurality of inks of different colors.

[0026] The liquid ejection device 100 includes a control unit 90, a moving mechanism 91, a conveying mechanism 92, and a circulation mechanism 94. The control unit 90 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory, and controls the various elements of the liquid ejection device 100.

[0027] The moving mechanism 91 conveys the medium P in the +Y direction under the control of the control unit 90. In the following, the +Y direction and the -Y direction opposite to the +Y direction are collectively referred to as the Y-axis direction.

[0028] The conveying mechanism 92 is controlled by the control unit 90 to cause the multiple liquid ejection heads 1 to reciprocate in the +X direction and the -X direction which is the opposite direction to the +X direction. In addition, hereinafter, the +X direction and the -X direction are collectively referred to as the X-axis direction. Here, the X-axis direction refers to the direction intersecting the Y-axis direction, including the direction orthogonal to the Y-axis direction. The conveying mechanism 92 includes a storage shell 921 and an endless belt 922 to which the storage shell 921 is fixed. In the storage shell 921, a plurality of liquid ejection heads 1 are stored in a manner arranged in the X-axis direction with the Y-axis direction as the long side direction. In addition, the liquid container 93 can also be stored in the storage shell 921 together with the liquid ejection head 1.

[0029] The circulation mechanism 94 supplies the ink stored in the liquid container 93 to the supply flow path 53 (see FIG. 5 ) provided in the liquid ejection head 1 under the control of the control unit 90. Figure 4 ). In addition, the circulation mechanism 94 is controlled by the control unit 90 to circulate the liquid stored in the discharge flow path 54 (see Figure 4 ) is recovered and the recovered ink is returned to the supply flow channel 53.

[0030] The control unit 90 controls the ejection operation of the liquid ejection head 1. Specifically, the control unit 90 supplies a driving signal COM for driving the liquid ejection head 1 and a control signal SI for controlling the liquid ejection head 1 to the liquid ejection head 1. Then, the liquid ejection head 1 is driven by the driving signal COM under the control of the control signal SI, and liquid is ejected from a plurality of nozzles N (see FIG. Figure 2 ) part or all of which ejects ink in the -Z direction.

[0031] The -Z direction is a direction that intersects the X-axis direction and the Y-axis direction, including directions perpendicular to the X-axis direction and the Y-axis direction. Hereinafter, the -Z direction and the +Z direction, which is the direction opposite to the -Z direction, are collectively referred to as the Z-axis direction. In this embodiment, the -Z direction is the direction of gravity, and the +Z direction is the direction opposite to gravity.

[0032] The liquid ejection head 1 ejects ink from some or all of the plurality of nozzles N in conjunction with the transport of the medium P by the moving mechanism 91 and the reciprocating motion of the liquid ejection head 1 by the transport mechanism 92, and causes the ejected ink to land on the surface of the medium P, thereby forming a desired image on the surface of the medium P. The liquid ejection device 100 of this embodiment is a serial-type liquid ejection device in which the liquid ejection head 1 reciprocates relative to the medium P to form an image.

[0033] Figure 2 It is an exploded perspective view of the liquid ejecting head 1. Figure 3 It is a schematic perspective view of the flow passage formed in the communicating plate 2 as viewed from an oblique direction. Figure 4 1 is an explanatory diagram of the flow path and circulation mechanism 94 of the liquid ejection device 100. Figure 4 The flow path of the liquid ejection head 1 is schematically shown as viewed from the +Z direction. Figure 5 for Figure 4 Cross-sectional view along line AA.

[0034] Appropriate reference Figures 2 to 5 , an overview of the liquid ejecting head 1 will be described.

[0035] like Figure 2 As shown, the liquid ejection head 1 includes a connecting plate 2, a pressure chamber substrate 3, a vibration plate 4, a piezoelectric element PZ arranged on the vibration plate 4, a storage chamber forming substrate 5, a sealing component (omitted from the figure), a wiring substrate 8, a nozzle substrate 60 and plastic sheets 61 and 62.

[0036] Here, the pressure chamber substrate 3, the vibration plate 4, the piezoelectric element PZ provided on the vibration plate 4, the reservoir forming substrate 5, the sealing member, and the wiring substrate 8 are provided closer to the +Z direction than the connecting plate 2. Meanwhile, the nozzle substrate 60 and the plastic sheets 61 and 62 are provided closer to the -Z direction than the connecting plate 2. The components constituting the liquid ejection head 1 are generally plate-shaped members extending in the Y-axis direction and are bonded to each other using, for example, an adhesive.

[0037] like Figure 2 As shown, the nozzle substrate 60 is a plate-shaped component with a plurality of nozzles N arranged along the Y-axis, forming a nozzle array Ln. The Y-axis corresponds to the first direction described below. The nozzles N are through-holes through which ink passes. The nozzle substrate 60 is manufactured by processing a single crystal silicon substrate using semiconductor manufacturing techniques, such as dry etching or wet etching. However, other known methods and materials may be used appropriately in the manufacture of the nozzle substrate 60.

[0038] A connecting plate 2 is provided at the +Z direction of the nozzle substrate 60. The connecting plate 2 is a plate-shaped member for forming a flow path for the ink. Figure 2 、 Figure 3 As shown, the connecting plate 2 is provided with a supply flow channel 21, a relay flow channel 22, a connecting flow channel 23, a communication flow channel 24, a nozzle flow channel 25, a communication flow channel 24, a connecting flow channel 23, a relay flow channel 26, and a discharge flow channel 27 in order from the -X direction toward the +X direction. Furthermore, these flow channels are connected to each other by being joined together via the structural components of the liquid ejection head 1 described above, and ink flows within the connected flow channels.

[0039] In the connecting plate 2, the supply flow channel 21 and the discharge flow channel 27 are through holes extending along the Y-axis direction. In addition, the relay flow channel 22, the connecting flow channel 23 in the -X direction, the connecting flow channel 24 in the -X direction, the nozzle flow channel 25, the connecting flow channel 24 in the +X direction, the connecting flow channel 23 in the +X direction, and the relay flow channel 26 are formed in a row along the Y-axis direction. In addition, the relay flow channel 22, the nozzle flow channel 25 and the relay flow channel 26 are formed on the surface in the -Z direction. In addition, the connecting flow channel 23 and the connecting flow channel 24 are through holes. The connecting plate 2 is manufactured in the same manner as the nozzle substrate 60, for example, by processing a single crystal silicon substrate using semiconductor manufacturing technology. However, other well-known methods and materials can also be appropriately used in the manufacture of the connecting plate 2. In addition, although the case where one relay channel 22 is connected to two connecting channels 23 is shown here, one relay channel 22 may be connected to four connecting channels 23 or may be connected to all connecting channels 23 arranged in parallel in the Y direction. The same applies to the relay channel 26.

[0040] A pressure chamber substrate 3 is provided at the +Z direction of the connecting plate 2. The pressure chamber substrate 3 is a plate-shaped member on which a plurality of pressure chambers CV are formed. Figure 2 As shown, multiple pressure chambers CV are arranged side by side along the Y-axis, with one row each in the -X and +X directions, for a total of two rows. A pressure chamber CV is a space called a cavity that applies pressure to the ink filled within it. The pressure chamber CV is formed by through-holes opening on both sides of the pressure chamber substrate 3 and has a long strip shape extending along the X-axis. Like the nozzle substrate 60, the pressure chamber substrate 3 is manufactured, for example, by processing a single crystal silicon substrate using semiconductor manufacturing technology. However, other known methods and materials may also be used to manufacture the pressure chamber substrate 3 as appropriate.

[0041] A vibration plate 4 is provided in the +Z direction of the pressure chamber substrate 3. The vibration plate 4 is a plate-shaped component that can be elastically deformed. Piezoelectric elements PZ are arranged on the +Z direction surface of the vibration plate 4 corresponding to each pressure chamber CV. Each piezoelectric element PZ is a passive element that is deformed by the supply of a drive signal COM and is in the shape of a long strip extending in the direction along the X-axis. A plurality of piezoelectric elements PZ are arranged along the Y-axis direction corresponding to the pressure chamber CV. When the vibration plate 4 vibrates in conjunction with the deformation of the piezoelectric element PZ, the pressure in the pressure chamber CV corresponding to the piezoelectric element PZ changes, and ink is ejected from the corresponding nozzle N.

[0042] A reservoir forming substrate 5 is provided at the +Z direction of the connecting plate 2. The reservoir forming substrate 5 is a component that is long in the Y-axis direction and forms a flow path for the ink. Specifically, a supply flow path 53 ( Figure 5 ) and a discharge flow channel 54 ( Figure 5 ). The supply flow channel 53 is provided so as to communicate with the supply flow channel 21 of the communication plate 2 and to extend in the Y-axis direction at the -X direction of the reservoir forming substrate 5. Furthermore, the discharge flow channel 54 is provided so as to communicate with the discharge flow channel 27 of the communication plate 2 and to extend in the Y-axis direction at the +X direction of the reservoir forming substrate 5.

[0043] like Figure 2 、 Figure 5 As shown, the reservoir forming substrate 5 is provided with an inlet 51 communicating with a supply flow channel 53 and a discharge port 52 communicating with a discharge flow channel 54. Ink is supplied from the liquid container 93 to the supply flow channel 53 via the inlet 51. Furthermore, ink stored in the discharge flow channel 54 is recovered via the discharge port 52. The ink recovered from the discharge port 52 is returned to the liquid container 93 storing the ink, thereby enabling the ink to circulate.

[0044] Furthermore, an opening 50 is provided in the reservoir forming substrate 5. Inside the opening 50, the pressure chamber substrate 3, the vibration plate 4, the wiring substrate 8, and a sealing member (not shown) are provided. The reservoir forming substrate 5 is formed, for example, by injection molding of a resin material. However, known materials and manufacturing methods may be used as appropriate for manufacturing the reservoir forming substrate 5.

[0045] like Figure 5 As shown, a plastic sheet 61 is provided on the surface of the connecting plate 2 in the -X direction and in the -Z direction to block the supply flow channel 21, the relay flow channel 22, and the connecting flow channel 23. The plastic sheet 61 is formed of an elastic material and absorbs the pressure fluctuation of the ink inside the supply flow channel 21, the relay flow channel 22, and the connecting flow channel 23. In addition, as shown in FIG. Figure 5 As shown, a plastic sheet 62 is provided on the surface of the connecting plate 2 in the +X direction and on the -Z side to block the discharge flow channel 27, the relay flow channel 26, and the connecting flow channel 23. The plastic sheet 62 is formed of an elastic material and absorbs pressure fluctuations of the ink within the discharge flow channel 27, the relay flow channel 26, and the connecting flow channel 23.

[0046] Reference Figures 3 to 5 The flow path structure for ejecting ink from a predetermined one of the plurality of nozzles N in the ejection head 1 of this embodiment will be described. In the following description, for convenience, the flow path structure for ejecting ink from one nozzle N will be referred to as a basic flow path structure.

[0047] In this embodiment, the basic flow path structure formed at the end portion in the +Y direction of the liquid ejecting head 1 is described by way of example. Furthermore, the basic flow path structure of this embodiment is a structure in which two adjacent pressure chambers CV in the -X direction and two adjacent pressure chambers CV in the +X direction, which are aligned in the Y-axis direction, which is the arrangement direction of the nozzle array Ln, are connected to one nozzle.

[0048] In this embodiment, the Y-axis direction corresponds to the first direction, the X-axis direction corresponds to the second direction, and the Z-axis direction corresponds to the third direction. In the following description, the Y-axis direction and the first direction, the X-axis direction and the second direction, and the Z-axis direction and the third direction are used appropriately.

[0049] The basic flow channel structure of this embodiment will be specifically described in order from the -X direction toward the +X direction.

[0050] The basic flow channel structure includes one relay flow channel 22 that communicates with the supply flow channel 21 and extends in the X-axis direction, and two connecting flow channels 23 that communicate with the one relay flow channel 22 and extend in the Z-axis direction (the third direction). Of these two connecting flow channels 23, the connecting flow channel 23 in the +Y direction is referred to as a first connecting flow channel 231. Furthermore, the other connecting flow channel 23 adjacent to the first connecting flow channel 231 in the -Y direction is referred to as a second connecting flow channel 232.

[0051] Moreover, the first connecting channel 231 is connected to a pressure chamber CV extending in the X-axis direction (second direction). A pressure chamber CV connected to the first connecting channel 231 is referred to as the first pressure chamber CV1. The first connecting channel 231 is connected to the end region of the first pressure chamber CV1 in the -X direction. In addition, the second connecting channel 232 is connected to a pressure chamber CV that is adjacent to the first pressure chamber CV1 in the Y-axis direction (first direction), specifically in the -Y direction, and extends in the X-axis direction (second direction). A pressure chamber CV connected to the second connecting channel 232 is referred to as the second pressure chamber CV2. The second connecting channel 232 is connected to the end region of the second pressure chamber CV2 in the -X direction.

[0052] Furthermore, the first pressure chamber CV1 is connected to a communication channel 24 extending in the Z-axis direction (the third direction). The communication channel 24 connected to the first pressure chamber CV1 is referred to as a first communication channel 241. The first communication channel 241 is connected to the end region of the first pressure chamber CV1 in the +X direction. Furthermore, the second pressure chamber CV2 is connected to a communication channel 24 extending in the Z-axis direction (the third direction). The communication channel 24 connected to the second pressure chamber CV2 is referred to as a second communication channel 242. The second communication channel 242 is connected to the end region of the second pressure chamber CV2 in the +X direction.

[0053] Furthermore, the first and second communication channels 241 and 242 communicate with a single nozzle channel 25 extending in the X-axis direction (second direction). The nozzle channel 25 extends in the X-axis direction (second direction) intersecting the Y-axis direction (first direction). The term "intersecting" encompasses perpendicular intersections and, even if not perpendicular, oblique intersections as long as they lie on the XY plane. The first and second communication channels 241 and 242 communicate with the -X-direction end of the nozzle channel 25.

[0054] When the nozzle flow channel 25 is viewed from the Z-axis direction, the nozzle N is located approximately at the center in the X-axis and Y-axis directions of the approximately rectangular nozzle flow channel 25. The term "approximately at the center" includes both the case where the nozzle N is exactly at the center and the case where the nozzle N can be considered as the center after allowing for errors.

[0055] In other words, the first communication channel 241 connects the first pressure chamber CV1 with the nozzle channel 25 and extends in the Z-axis direction (third direction) perpendicular to both the Y-axis direction (first direction) and the X-axis direction (second direction). Furthermore, the second communication channel 242 connects the second pressure chamber CV2 with the nozzle channel 25 and extends in the Z-axis direction (third direction).

[0056] Furthermore, one nozzle flow channel 25 communicates with two communication flow channels 24 extending in the Z-axis direction (third direction). Of these two communication flow channels 24, the communication flow channel 24 in the +Y direction is designated as the third communication flow channel 243. Furthermore, the other communication flow channel 24 adjacent to the third communication flow channel 243 in the -Y direction is designated as the fourth communication flow channel 244. The third communication flow channel 243 and the fourth communication flow channel 244 communicate with the end portion of the nozzle flow channel 25 in the +X direction.

[0057] Furthermore, the third communication channel 243 communicates with a pressure chamber CV extending in the X-axis direction. The pressure chamber CV communicated with the third communication channel 243 is referred to as the third pressure chamber CV3. The third communication channel 243 communicates with the end region of the third pressure chamber CV3 in the -X direction. Furthermore, the fourth communication channel 244 communicates with a pressure chamber CV extending in the Z-axis direction (the third direction). The pressure chamber CV communicated with the fourth communication channel 244 is referred to as the fourth pressure chamber CV4. The fourth communication channel 244 communicates with the end region of the fourth pressure chamber CV4 in the -X direction.

[0058] The third pressure chamber CV3 is located in the X-axis direction (second direction), specifically, the +X direction, relative to the first pressure chamber CV1. The fourth pressure chamber CV4 is located adjacent to the third pressure chamber CV3 in the Y-axis direction (first direction), specifically, the -Y direction.

[0059] In other words, the third communication channel 243 connects the third pressure chamber CV3 with the nozzle channel 25 and extends in the Z-axis direction (third direction), which is perpendicular to both the Y-axis direction (first direction) and the X-axis direction (second direction). Furthermore, the fourth communication channel 244 connects the fourth pressure chamber CV4 with the nozzle channel 25 and extends in the Z-axis direction (third direction).

[0060] Furthermore, the third pressure chamber CV3 is connected to a connecting flow channel 23 extending in the Z-axis direction (the third direction). The connecting flow channel 23 connected to the third pressure chamber CV3 is referred to as a third connecting flow channel 233. The third connecting flow channel 233 is connected to the end region of the third pressure chamber CV3 in the +X direction. Furthermore, the fourth pressure chamber CV4 is connected to a connecting flow channel 23 extending in the Z-axis direction (the third direction). The connecting flow channel 23 connected to the fourth pressure chamber CV4 is referred to as a fourth connecting flow channel 234. The fourth connecting flow channel 234 is connected to the end region of the fourth pressure chamber CV4 in the +X direction.

[0061] Furthermore, the third connecting flow channel 233 and the fourth connecting flow channel 234 communicate with one relay flow channel 26 extending in the X-axis direction. The relay flow channel 26 communicates with the discharge flow channel 27 .

[0062] When the flow channels from the relay flow channel 22 to the relay flow channel 26 are viewed from the Z-axis direction, in this embodiment, they are configured to be approximately point-symmetrical with respect to the single nozzle N. The point symmetry here is not strictly point-symmetrical, but rather a concept that allows for approximately point symmetry, including deformation caused by molding such as etching.

[0063] On the vibration plate 4 facing the first pressure chamber CV1 in the +Z direction, a first piezoelectric element PZ1 is provided on the surface in the +Z direction, extending in the X-axis direction. Similarly, on the vibration plate 4 facing the second pressure chamber CV2 in the +Z direction, a second piezoelectric element PZ2 is provided on the surface in the +Z direction, extending in the X-axis direction. Similarly, on the vibration plate 4 facing the third pressure chamber CV3 in the +Z direction, a third piezoelectric element PZ3 is provided on the surface in the +Z direction, extending in the X-axis direction. Similarly, on the vibration plate 4 facing the fourth pressure chamber CV4 in the +Z direction, a fourth piezoelectric element PZ4 is provided on the surface in the +Z direction, extending in the X-axis direction.

[0064] As described above, the flow channels of the liquid ejection head 1 have a basic flow channel structure as one structural unit or one group, and are arranged in a row at predetermined intervals in the Y-axis direction according to the number of nozzles N.

[0065] Figure 6 It is an enlarged cross-sectional view of the vicinity of the piezoelectric element PZ.

[0066] like Figure 6As shown, in detail, the vibration plate 4 has a first layer 41 as an elastic film and a second layer 42 as an insulating film, and these layers are stacked in this order in the +Z direction. The first layer 41 is, for example, an elastic film made of silicon oxide (SiO2). The elastic film is formed, for example, by thermally oxidizing the surface of one side of a single crystal silicon substrate. The second layer 42 is, for example, an insulating film made of zirconium oxide (ZrO2). The insulating film is formed, for example, by forming a zirconium layer by sputtering and thermally oxidizing the formed zirconium layer. In addition, a part or all of the vibration plate 4 can also be integrally formed of the same material as the pressure chamber substrate 3. In addition, the vibration plate 4 can also be composed of a layer of a single material.

[0067] like Figure 6 As shown, the piezoelectric element PZ is a stacked body in which the piezoelectric body 432 is interposed between the lower electrode 431 and the upper electrode 433, and these components are stacked in the Z-axis direction. The piezoelectric element PZ is a portion where the lower electrode 431, the upper electrode 433, and the piezoelectric body 432 overlap when viewed from the Z-axis direction. In addition, a pressure chamber CV is provided in the -Z direction of the piezoelectric element PZ. In this embodiment, the lower electrode 431 is a common electrode common to the plurality of piezoelectric elements PZ, and the upper electrode 433 is an independent electrode independently provided with respect to the plurality of piezoelectric elements PZ. However, a structure in which the lower electrode 431 is provided as an independent electrode and the upper electrode 433 is provided as a common electrode may also be provided.

[0068] Figure 7 for Figure 4 Cross-sectional view of line BB in.

[0069] like Figure 2 、 Figure 5 、 Figure 7 As shown, a wiring substrate 8 is mounted on the +Z direction surface of the vibration plate 4. The wiring substrate 8 is a component for electrically connecting the control unit 90 and the liquid ejection head 1. The wiring substrate 8 can preferably be a flexible wiring substrate such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable).

[0070] A driving circuit 81 for driving the piezoelectric element PZ is electrically connected to the wiring substrate 8. The driving circuit 81 is a circuit that switches whether to supply the driving signal COM to the piezoelectric element PZ under the control of the control signal SI. Figure 6 As shown, the driving circuit 81 supplies the driving signal COM to the upper electrode 433 of the piezoelectric element PZ via the wiring portion 44 formed on the vibration plate 4 .

[0071] Wiring substrate 8 includes a main body 82 on which drive circuit 81 is mounted, and a connection end portion 83 bent approximately 90 degrees relative to main body 82 and connected to diaphragm 4. When wiring substrate 8 is mounted on diaphragm 4, connection end portion 83 is approximately parallel to diaphragm 4, and main body 82 is approximately perpendicular to diaphragm 4.

[0072] The liquid ejection head 1 of this embodiment includes a sealing member (not shown). The sealing member protects the plurality of piezoelectric elements PZ and reinforces the mechanical strength of the pressure chamber substrate 3 and the vibration plate 4. The sealing member is provided with a recessed portion for accommodating the plurality of piezoelectric elements PZ and is bonded to the +Z direction surface of the vibration plate 4, for example, using an adhesive, while being surrounded by the opening 50 of the reservoir forming substrate 5.

[0073] like Figures 3 to 5 As shown, in this embodiment, ink supplied from the liquid container 93 to the inlet 51 flows into the supply flow channel 21 of the communicating plate 2 via the supply flow channel 53. Then, a portion of the ink that has flowed into the supply flow channel 21 flows into the first pressure chamber CV1 via the relay flow channel 22 and the first connecting flow channel 231. Furthermore, a portion of the ink that has flowed into the supply flow channel 21 flows into the second pressure chamber CV2 via the relay flow channel 22 and the second connecting flow channel 232.

[0074] A portion of the ink that has flowed into the first pressure chamber CV1 flows into the nozzle flow channel 25 via the first communication channel 241. Furthermore, a portion of the ink that has flowed into the second pressure chamber CV2 flows into the nozzle flow channel 25 via the second communication channel 242. Furthermore, a portion of the ink that has flowed into the nozzle flow channel 25 flows into the third pressure chamber CV3 via the third communication channel 243. Furthermore, a portion of the ink that has flowed into the nozzle flow channel 25 flows into the fourth pressure chamber CV4 via the fourth communication channel 244.

[0075] Furthermore, a portion of the ink that has flowed into the third pressure chamber CV3 flows into the relay flow channel 26 via the third connecting flow channel 233. A portion of the ink that has flowed into the fourth pressure chamber CV4 flows into the relay flow channel 26 via the fourth connecting flow channel 234. The ink that has flowed into the relay flow channel 26 is discharged from the discharge port 52 via the discharge flow channel 27 and the discharge flow channel 54.

[0076] When the first piezoelectric element PZ1 is driven by the drive signal COM, a portion of the ink filled in the first pressure chamber CV1 is ejected from the nozzle N via the first communication channel 241 and the nozzle channel 25. Furthermore, when the second piezoelectric element PZ2 is driven by the drive signal COM, a portion of the ink filled in the second pressure chamber CV2 is ejected from the nozzle N via the second communication channel 242 and the nozzle channel 25.

[0077] Furthermore, when the third piezoelectric element PZ3 is driven by the drive signal COM, a portion of the ink filled in the third pressure chamber CV3 is ejected from the nozzle N via the third communication channel 243 and the nozzle channel 25. Furthermore, when the fourth piezoelectric element PZ4 is driven by the drive signal COM, a portion of the ink filled in the fourth pressure chamber CV4 is ejected from the nozzle N via the fourth communication channel 244 and the nozzle channel 25.

[0078] In this embodiment, when ejecting ink from the nozzle N, the drive circuit 81 supplies substantially the same waveform of the drive signal COM to the four piezoelectric elements PZ1 to PZ4 corresponding to one nozzle N. However, in order to maintain the ejection performance from the nozzle N, different waveforms may be supplied to each of them.

[0079] The liquid ejection head 1 according to this embodiment can eject ink filled within four pressure chambers CV: the first pressure chamber CV1, the second pressure chamber CV2, the third pressure chamber CV3, and the fourth pressure chamber CV4, from a single nozzle N. Therefore, in the liquid ejection head 1, compared to a method in which ink filled within only one pressure chamber is ejected from a single nozzle N, the amount of ink ejected from a single nozzle N can be increased, thereby improving ejection performance. Consequently, even inks with high viscosity and large particle sizes can be properly ejected.

[0080] Figure 8 for Figure 4 In detail, Figure 8 It is a cross-sectional view showing a state where the partition wall 71 is viewed from the -X direction. Figure 9 for Figure 4 In detail, Figure 9 It is a cross-sectional view of the partition wall 72 as viewed from the +X direction.

[0081] like Figure 3 、 Figure 4 、 Figure 7 、 Figure 8As shown, in this embodiment, in the liquid ejection head 1, a partition wall 71 extending in the -Z direction and in the X-axis direction is formed between the first connecting flow channel 241 and the second connecting flow channel 242 extending along the Z-axis direction (third direction) and in the area to the nozzle flow channel 25.

[0082] In detail, Figure 8 As shown, the partition wall 71 includes a pressure chamber-side partition wall 715 formed between the first pressure chamber CV1 and the second pressure chamber CV2. Furthermore, the partition wall 71 includes a first communication channel inner wall surface 713 extending in the Z-axis direction (the third direction), forming the inner wall surface of the first communication channel 241 on the second communication channel 242 side. Furthermore, the partition wall 71 includes a second communication channel inner wall surface 714 extending in the Z-axis direction (the third direction), forming the inner wall surface of the second communication channel 242 on the first communication channel 241 side.

[0083] In addition, if Figure 8 As shown, when viewing the partition wall 71 from the X-axis direction (the second direction), the inner wall surface of the first connecting flow channel 241 on the second connecting flow channel 242 side includes a first inclined surface 711 extending in a fourth direction, which is an inclined direction intersecting both the Y-axis direction (the first direction) and the Z-axis direction (the third direction). Furthermore, the first inclined surface 711 is connected to the first connecting flow channel inner wall surface 713. Hereinafter, the fourth direction will be referred to as fourth direction D4.

[0084] In addition, if Figure 8 As shown, when observing the partition wall 71 from the X-axis direction (second direction), the inner wall surface of the second connecting flow channel 242 located on the side of the first connecting flow channel 241 includes a second inclined surface 712 extending in a fifth direction that is an inclined direction intersecting the Y-axis direction (first direction), the Z-axis direction (third direction) and the fourth direction D4. Moreover, the second inclined surface 712 is connected to the inner wall surface 714 of the second connecting flow channel. In addition, hereinafter, the fifth direction will be referred to as the fifth direction D5. In addition, as Figure 8 As shown, the first inclined surface 711 and the second inclined surface 712 are connected to each other.

[0085] like Figure 3 、 Figure 4 、 Figure 7 、 Figure 9 As shown, in this embodiment, in the liquid ejection head 1, a partition wall 72 extending in the -Z direction and in the X-axis direction is formed between the third connecting flow channel 243 and the fourth connecting flow channel 244 extending along the Z-axis direction (third direction) and in the area to the nozzle flow channel 25.

[0086] In detail, Figure 9As shown, the partition wall 72 includes a pressure chamber-side partition wall 725 formed between the third pressure chamber CV3 and the fourth pressure chamber CV4. Furthermore, the partition wall 72 includes a third communication channel inner wall surface 723 extending in the Z-axis direction (the third direction), forming the inner wall surface of the third communication channel 243 on the fourth communication channel 244 side. Furthermore, the partition wall 72 includes a fourth communication channel inner wall surface 724 extending in the Z-axis direction (the third direction), forming the inner wall surface of the fourth communication channel 244 on the third communication channel 243 side.

[0087] In addition, if Figure 9 As shown, when the partition wall 72 is viewed from the X-axis direction (the second direction), the inner wall surface of the third connecting flow channel 243 on the fourth connecting flow channel 244 side includes a third inclined surface 721 extending in a fourth direction D4 that intersects both the Y-axis direction (the first direction) and the Z-axis direction (the third direction). Furthermore, the third inclined surface 721 is connected to the third connecting flow channel inner wall surface 723.

[0088] In addition, if Figure 9 As shown, when observing the partition wall 72 from the X-axis direction (second direction), the inner wall surface of the fourth communication flow channel 244 located on the third communication flow channel 243 side includes a fourth inclined surface 722 extending in a fifth direction D5 that intersects the Y-axis direction (first direction), the Z-axis direction (third direction), and the fourth direction D4. Moreover, the fourth inclined surface 722 is connected to the inner wall surface 724 of the fourth communication flow channel. In addition, as shown in FIG. Figure 9 As shown, the third inclined surface 721 and the fourth inclined surface 722 are connected to each other.

[0089] In addition, if Figure 8 、 Figure 9 As shown, in this embodiment, when observing the partition walls 71 and 72 from the X-axis direction (second direction), the fourth direction D4 is inclined at an angle α of 60 degrees relative to the Y-axis direction (first direction). In addition, the fifth direction D5 is also inclined at an angle β of 60 degrees relative to the Y-axis direction (first direction). In addition, the inclination angle α of the fourth direction D4 and the inclination angle β of the fifth direction D5 are not limited to being inclined at approximately 60 degrees relative to the Y-axis direction (first direction). The inclination angles α and β may be inclined within a range of 30 degrees to 70 degrees relative to the Y-axis direction (first direction).

[0090] Figure 10 It is an enlarged cross-sectional view showing the protective film 75 on the partition wall 71 .

[0091] The protective film 75 is provided on the outer surface of the partition wall 71 of this embodiment. Specifically, the protective film 75 is provided on the first inclined surface 711, the second inclined surface 712, the first communication flow path inner wall surface 713, and the second communication flow path inner wall surface 714.

[0092] In the present embodiment, the flow passages formed in the communicating plate 2 are provided with the protective film 75 similarly to the partition walls 71 .

[0093] The protective film 75 includes a first layer 751 laminated on the outer surface of the partition wall 71 and a second layer 752 laminated on the outer surface of the laminated first layer 751. The first layer 751 is composed of silicon (Si) oxide, and the second layer 752 is composed of tantalum (Ta) oxide (TaOx).

[0094] As described above, the connecting plate 2 of this embodiment, including the partition wall 71, is constructed using unoxidized silicon (Si) such as single crystal silicon as a base material. Furthermore, the first layer 751 is composed of, for example, a silicon (Si) oxide such as silicon dioxide (SiO2) or silicon monoxide (SiO). The second layer 752 is composed of, for example, a tantalum (Ta) oxide (TaOx) such as tantalum oxide (TaO3) or tantalum pentoxide (Ta2O5). Furthermore, in addition to tantalum oxide (TaOx), the second layer 752 may also be composed of any one of hafnium oxide (HfOx), diamond-like carbon (DLC), and aluminum oxide (Al2O3).

[0095] In this embodiment, the first layer 751 is formed by thermal oxidation of the silicon substrate constituting the partition wall 71. Specifically, a silicon substrate such as a silicon wafer is first placed in a firing furnace. Furthermore, the atmosphere in the firing furnace is adjusted to an oxygen atmosphere. In the firing furnace, the silicon substrate is heat-treated at, for example, 200°C. As a result, the oxygen in the firing furnace combines with the silicon in the silicon substrate, forming a film of the first layer 751 on the outer surface of the silicon substrate including the partition wall 71. The thickness of the first layer 751 is, for example, in the range of 1 nm to 100 nm.

[0096] The second layer 752 is formed on the outer surface of the first layer 751 by, for example, atomic layer deposition (ALD). Specifically, the silicon substrate on which the first layer 751 is formed is taken out of the sintering furnace and placed in an ALD film forming device. Then, by coating tantalum on the outer surface of the first layer 751 and forming a film, a film of the second layer 752 is stacked on the outer surface of the first layer 751. The thickness of the second layer 752 is, for example, in the range of 1 nm to 50 nm. In addition, the second layer 752 can also be formed by a thin film forming method implemented by plasma CVD instead of atomic layer deposition. In this way, a partition wall 71 having a structure in which the first layer 751 and the second layer 752 are stacked can be obtained.

[0097] Here, return to Figure 4 The structure and operation of supplying ink discharged from the discharge flow path 54 to the supply flow path 53 will be described with a focus on the circulation mechanism 94 of this embodiment.

[0098] like Figure 4 As shown, the flow channels of the liquid ejection head 1 are formed into a structural unit or a group of the basic flow channel structure as described above, and are arranged in a row at predetermined intervals in the Y-axis direction according to the number of nozzles N. In addition, the plurality of flow channels formed by the basic flow channel structure are connected to the supply flow channel 21 and the discharge flow channel 27, which are common flow channels. In other words, the plurality of flow channels formed by the basic flow channel structure are connected to the supply flow channel 53 and the discharge flow channel 54, which are common flow channels.

[0099] The supply flow path 21 and the supply flow path 53 store ink for supply to the flow paths formed by the basic flow path structure. Furthermore, the discharge flow path 27 and the discharge flow path 54 store ink that is not used for ejection but is discharged from the flow paths formed by the basic flow path structure.

[0100] A circulation mechanism 94 is connected to the supply flow channel 53 and the discharge flow channel 54. The circulation mechanism 94 supplies ink to the supply flow channel 53 and recovers ink discharged from the discharge flow channel 54 for resupply to the supply flow channel 53. The circulation mechanism 94 includes a first supply pump 941, a second supply pump 942, a storage tank 943, a recovery flow channel 944, and a supply flow channel 945.

[0101] The first supply pump 941 is a pump that supplies ink stored in the liquid container 93 to the storage container 943. The storage container 943 is a sub-tank that temporarily stores the ink supplied from the liquid container 93. The recovery flow path 944 is a flow path that connects the discharge flow path 54 and the storage container 943 and recovers the ink from the discharge flow path 54 into the storage container 943.

[0102] The ink stored in the liquid container 93 is supplied to the storage container 943 from the first supply pump 941. Furthermore, ink discharged from each flow channel formed by the basic flow channel structure into the discharge flow channel 54 is supplied to the storage container 943 via the recovery flow channel 944. The second supply pump 942 is a pump that delivers the ink stored in the storage container 943. The supply flow channel 945 is a flow channel that connects the supply flow channel 53 and the storage container 943 and supplies ink from the storage container 943 to the supply flow channel 53.

[0103] According to this embodiment, the following effects can be obtained.

[0104] The liquid ejection head 1 of this embodiment has a partition wall 71 extending in the -Z direction and the X direction, formed between the first communicating flow channel 241 and the second communicating flow channel 242, both extending in the Z-axis direction (third direction), and in the region extending to the nozzle flow channel 25. Furthermore, the inner wall surface of the first communicating flow channel 241, located on the side of the second communicating flow channel 242, includes a first inclined surface 711 extending in a fourth direction D4 that intersects both the Y-axis direction (first direction) and the Z-axis direction (third direction). Furthermore, the inner wall surface of the second communicating flow channel 242, located on the side of the first communicating flow channel 241, includes a second inclined surface 712 extending in a fifth direction D5 that intersects the Y-axis direction (first direction), the Z-axis direction (third direction), and the fourth direction D4.

[0105] According to this structure, when the first piezoelectric element PZ1 is driven, a portion of the ink filling the first pressure chamber CV1 is ejected from the nozzle N via the first communicating channel 241 and the nozzle channel 25. Similarly, when the second piezoelectric element PZ2 is driven, a portion of the ink filling the second pressure chamber CV2 is ejected from the nozzle N via the second communicating channel 242 and the nozzle channel 25. In this case, if bubbles are contained within the ink flowing through the first communicating channel 241 and the second communicating channel 242, the bubbles can be moved smoothly in the +Z direction, compared to the conventional technique where the bubbles are trapped when the lower end surface of the partition wall is approximately parallel to the XY plane. Thus, in a liquid ejection head 1 with this structure, a decrease in ejection efficiency can be prevented, thereby maintaining ejection efficiency.

[0106] Furthermore, the partition wall 71 includes the first inclined surface 711 inclined in the fourth direction D4 and the second inclined surface 712 inclined in the fifth direction D5 , thereby allowing bubbles in the ink to move in a balanced manner toward the first and second communication channels 241 and 242 .

[0107] In the liquid ejection head 1 of this embodiment, the inner wall surface of the first communication flow channel 241 on the second communication flow channel 242 side has a first communication flow channel inner wall surface 713 extending in the Z-axis direction (third direction) and connected to the first inclined surface 711 .

[0108] According to this configuration, the bubbles can be moved smoothly in the +Z direction.

[0109] In the liquid ejection head 1 of this embodiment, the first inclined surface 711 and the second inclined surface 712 are connected to each other.

[0110] According to this structure, the bubbles in the ink can be moved to the first communication flow channel 241 side and the second communication flow channel 242 side in a more balanced manner.

[0111] The liquid ejection head 1 of this embodiment further includes a third pressure chamber CV3, a fourth pressure chamber CV4, a third connecting flow channel 243, and a fourth connecting flow channel 244. Furthermore, a partition wall 72 extending in the -Z direction and in the X-axis direction (second direction) is formed between the third connecting flow channel 243 and the fourth connecting flow channel 244, which extend in the Z-axis direction (third direction), and in the region extending to the nozzle flow channel 25. Furthermore, the inner wall surface of the third connecting flow channel 243 on the side of the fourth connecting flow channel 244 includes a third inclined surface 721 extending in the fourth direction D4. Furthermore, the inner wall surface of the fourth connecting flow channel 244 on the side of the third connecting flow channel 243 includes a fourth inclined surface 722 extending in the fifth direction D5.

[0112] According to this structure, when the third piezoelectric element PZ3 is driven, a portion of the ink filling the third pressure chamber CV3 is ejected from the nozzle N via the third communicating channel 243 and the nozzle channel 25. Similarly, when the fourth piezoelectric element PZ4 is driven, a portion of the ink filling the fourth pressure chamber CV4 is ejected from the nozzle N via the fourth communicating channel 244 and the nozzle channel 25. In this case, if bubbles are contained within the ink flowing through the third communicating channel 243 and the fourth communicating channel 244, the bubbles can be moved smoothly in the +Z direction, compared to the conventional technique where the bubbles are trapped when the lower end surface of the partition wall is approximately parallel to the XY plane. Thus, in a liquid ejection head 1 with this structure, a decrease in ejection efficiency can be prevented, thereby maintaining ejection efficiency.

[0113] In the liquid ejection head 1 of the present embodiment, the fourth direction D4 and the fifth direction D5 are inclined at 60 degrees with respect to the Y-axis direction (first direction).

[0114] According to this configuration, the bubbles can be smoothly moved in the +Z direction.

[0115] In addition, the fourth direction D4 and the fifth direction D5 only need to be inclined within a range of 30 degrees to 70 degrees with respect to the Y-axis direction (first direction) to achieve the same effect.

[0116] In the liquid ejection head 1 of this embodiment, a protective film 75 is provided on the outer surface of the partition wall 71. Specifically, the protective film 75 is provided on the first inclined surface 711, the second inclined surface 712, the first communication channel inner wall surface 713, and the second communication channel inner wall surface 714. Furthermore, the protective film 75 includes a first layer 751 and a second layer 752 laminated on the outer surface of the first layer 751. Furthermore, the first layer 751 is composed of silicon oxide, and the second layer 752 is composed of tantalum oxide.

[0117] This structure prevents damage to the partition wall 71 and protects it. Furthermore, in this embodiment, the first inclined surface 711 and the second inclined surface 712 are connected to each other. While the corner where the inclined surfaces meet is acute, the presence of the protective film 75 eliminates the sharp corner and creates a gently connected corner, thereby preventing damage to the corner and protecting it. This improves the ink resistance of the partition walls 71 and 72 and enhances the bonding strength between the layers.

[0118] In the liquid ejection head 1 of this embodiment, the first layer 751 is made of silicon oxide, and the second layer 752 is made of any one of hafnium oxide, diamond-like carbon, and aluminum oxide.

[0119] This structure eliminates the sharp corners where the inclined surfaces connect, creating gently connected corners. This prevents and protects the corners from chipping, etc. Thus, the partition walls 71 and 72 can achieve improved resistance to ink and increased bonding strength between the layers.

[0120] The liquid ejecting apparatus 100 of this embodiment includes the above-described liquid ejecting head 1 and a control unit 90 that controls the ejection operation from the liquid ejecting head 1 .

[0121] According to this configuration, by providing the liquid ejection head 1 that can smoothly move bubbles in the +Z direction, it is possible to realize the liquid ejection apparatus 100 that can prevent a decrease in ejection efficiency and maintain ejection efficiency.

[0122] 2. Second Implementation

[0123] Figure 11 : is a cross-sectional view showing a partition wall 71A according to the second embodiment. Figure 11This is a cross-sectional view showing a state where the partition wall 71A is viewed from the -X direction, and is similar to that of the first embodiment. Figure 8 The corresponding figure.

[0124] The partition wall 71A of this embodiment is different from the partition wall 71 of the first embodiment in that the top end portion of the partition wall 71A in the -Z direction is different. The other structures are the same as those of the first embodiment. In addition, in the following description, the differences from the first embodiment will be mainly described, and the description of the same matters will be omitted. In addition, in Figure 11 In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals.

[0125] like Figure 11 As shown, the partition wall 71A includes a pressure chamber-side partition wall 715, a first communication channel inner wall surface 713A, a second communication channel inner wall surface 714A, a first inclined surface 711A, a second inclined surface 712A, and the nozzle channel inner wall surface 251. The first communication channel inner wall surface 713A and the second communication channel inner wall surface 714A of the partition wall 71A extend in the -Z direction from the first communication channel inner wall surface 713 and the second communication channel inner wall surface 714 of the first embodiment. As a result, the top ends of the first inclined surface 711 and the second inclined surface 712 of the first embodiment reach the nozzle channel inner wall surface 251, which serves as the inner circumferential surface of the nozzle channel 25 in the +Z direction.

[0126] Therefore, the top end of the partition wall 71A in this embodiment is formed by a first inclined surface 711A extending in the fourth direction D4, a second inclined surface 712A extending in the fifth direction D5, and the nozzle flow path inner wall surface 251. In other words, the nozzle flow path inner wall surface 251 constituting the partition wall 71A in this embodiment extends in the X-axis direction (the second direction) and connects the first inclined surface 711A and the second inclined surface 712A. Furthermore, the nozzle flow path inner wall surface 251 is substantially parallel to the XY plane.

[0127] According to this embodiment, the following effects can be obtained.

[0128] The partition wall 71A in the liquid ejection head 1A of this embodiment has a nozzle flow path inner wall surface 251 extending in the X-axis direction (second direction) and connected to the first inclined surface 711A and the second inclined surface 712A.

[0129] According to this structure, when bubbles are contained in the ink flowing in the first connecting flow channel 241 and the second connecting flow channel 242, although bubbles are retained in the portion of the nozzle flow channel inner wall surface 251 extending in the X-axis direction (second direction) to constitute the partition wall 71A, the bubbles can be smoothly moved in the +Z direction by the first inclined surface 711A and the second inclined surface 712A formed on both sides thereof.

[0130] 3. Third Implementation

[0131] Figure 12 : is a cross-sectional view showing a partition wall 71B according to the third embodiment. Figure 12 This is a cross-sectional view showing a state where the partition wall 71B is viewed from the -X direction, and is similar to that of the first embodiment. Figure 8 The corresponding figure.

[0132] The partition wall 71B of this embodiment is different from the partition wall 71 of the first embodiment in that the top end portion of the partition wall 71B in the -Z direction is different. The other structures are the same as those of the first embodiment. In addition, in the following description, the differences from the first embodiment will be mainly described, and the description of the same matters will be omitted. In addition, in Figure 12 In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals.

[0133] like Figure 12 As shown, the partition wall 71B includes a pressure chamber side partition wall 715, a first connecting flow channel inner wall surface 713B, a second connecting flow channel inner wall surface 714B, and a first inclined surface 711B. The partition wall 71B of this embodiment is constructed in a state where the second inclined surface 712 of the partition wall 71 of the first embodiment is removed. Specifically, the partition wall 71B is in a state where the first inclined surface 711B formed by extending the first inclined surface 711 of the first embodiment in the fourth direction D4 and the second connecting flow channel inner wall surface 714B formed by extending the second connecting flow channel inner wall surface 714 of the first embodiment in the -Z direction are connected. In other words, the first inclined surface 711B constituting the partition wall 71B of this embodiment is connected to the first connecting flow channel inner wall surface 713B and the second connecting flow channel inner wall surface 714B.

[0134] According to this embodiment, the following effects can be obtained.

[0135] The partition wall 71B in the liquid ejection head 1B of this embodiment has a second communication flow path inner wall surface 714B, and the first inclined surface 711B connects the first communication flow path inner wall surface 713B and the second communication flow path inner wall surface 714B.

[0136] According to this configuration, when bubbles are contained in the ink flowing through the first communication flow channel 241 and the second communication flow channel 242 , the first inclined surface 711B can smoothly move the bubbles in the +Z direction.

[0137] 4. Fourth embodiment

[0138] Figure 13 : is a cross-sectional view showing a nozzle flow channel 25C according to the fourth embodiment. Figure 13 It is a cross-sectional view showing a state in which the nozzle flow path 25C is viewed from the −X direction in the region of the partition wall 71 .

[0139] like Figure 13 As shown, the nozzle channel 25C of this embodiment is different from the nozzle channel 25 of the first embodiment in that it extends in the Y-axis direction (first direction). The other structures are the same as those of the first embodiment. In addition, in the subsequent description, the differences from the first embodiment will be mainly described, and the description of the same matters will be omitted. In addition, in Figure 13 In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals.

[0140] The first communication channel 241 extending in the Z-axis direction (third direction) has a first communication channel outer wall surface 2411 as an outer wall surface when viewed from the X-axis direction. Furthermore, the second communication channel 242 extending in the Z-axis direction (third direction) has a second communication channel outer wall surface 2421 as an outer wall surface when viewed from the X-axis direction.

[0141] Furthermore, regarding the nozzle flow channel 25C extending in the Y-axis direction (first direction), when viewed from the X-axis direction, the outer wall surface in the +Y direction is referred to as the first nozzle flow channel outer wall surface 252. Furthermore, regarding the nozzle flow channel 25C, when viewed from the X-axis direction, the outer wall surface in the -Y direction is referred to as the second nozzle flow channel outer wall surface 253.

[0142] In this case, in this embodiment, the first nozzle flow channel outer wall surface 252 is smoothly connected to the first connecting flow channel outer wall surface 2411 in the X-axis direction without any height difference. In addition, the second nozzle flow channel outer wall surface 253 is also smoothly connected to the second connecting flow channel outer wall surface 2421 in the X-axis direction, similarly to the first nozzle flow channel outer wall surface 252.

[0143] According to this embodiment, the following effects can be obtained.

[0144] In the liquid ejection head 1C of this embodiment, the first nozzle flow channel outer wall surface 252 is smoothly connected to the first connecting flow channel outer wall surface 2411 without any height difference in the X-axis direction, and the second nozzle flow channel outer wall surface 253 is also smoothly connected to the second connecting flow channel outer wall surface 2421 without any height difference in the X-axis direction.

[0145] With this structure, ink flowing from the first pressure chamber CV1 into the first communication channel 241 can smoothly flow into the nozzle channel 25C. In addition, ink flowing from the second pressure chamber CV2 into the second communication channel 242 can smoothly flow into the nozzle channel 25C.

[0146] 5. Modification 1

[0147] In the first to fourth embodiments, the liquid ejecting heads 1, 1A, 1B, and 1C are configured as a basic flow path structure in which two adjacent pressure chambers CV in the -X direction and two adjacent pressure chambers CV in the +X direction, which are aligned in the Y-axis direction (the arrangement direction of the nozzle rows Ln), communicate with one nozzle N. However, the present invention is not limited to this configuration.

[0148] The liquid ejection head of this embodiment may be configured such that two adjacent pressure chambers CV in the -X direction and one pressure chamber CV in the +X direction are connected to one nozzle N. Alternatively, the liquid ejection head may be configured such that three or more adjacent pressure chambers CV in the -X direction and three or more adjacent pressure chambers CV in the +X direction are connected to one nozzle N. Alternatively, the liquid ejection head may be configured such that two adjacent pressure chambers CV in the -X direction are connected to one nozzle N. Alternatively, the liquid ejection head of this embodiment may be configured such that three or more adjacent pressure chambers CV in the -X direction are connected to one nozzle N.

[0149] In short, the liquid ejection head only needs to be configured so that a plurality of pressure chambers CV adjacent to each other in the Y-axis direction (first direction) communicate with one nozzle N.

[0150] 6. Modification 2

[0151] A protective film 75 is provided on the outer surface of the partition wall 71 of the first embodiment. Specifically, the protective film 75 is provided on the first inclined surface 711, the second inclined surface 712, the first connecting flow channel inner wall surface 713, and the second connecting flow channel inner wall surface 714. However, this is not limiting, and the protective film 75 may be provided only on the first inclined surface 711. This prevents damage to the first inclined surface 711 and protects it.

[0152] 7. Modification 3

[0153] Although the first to fourth embodiments illustrate a serial-type liquid ejection device 100 in which the liquid ejection heads 1, 1A, 1B, and 1C reciprocate in the width direction of the medium P, the present invention is not limited to this type. The liquid ejection device of this embodiment may also be a line-type liquid ejection device in which a plurality of nozzles N are distributed across the entire width of the medium P.

[0154] Explanation of symbols

[0155] 1…liquid ejection head; 25…nozzle flow channel; 75…protective film; 90…control unit; 100…liquid ejection device; 241…first connecting flow channel; 242…second connecting flow channel; 243…third connecting flow channel; 244…fourth connecting flow channel; 251…inner wall surface of nozzle flow channel; 252…outer wall surface of first nozzle flow channel; 711…first inclined surface; 712…second inclined surface; 713…inner wall surface of first connecting flow channel; 714…inner wall surface of second connecting flow channel; 721…third inclined surface; 751…first layer; 752…second layer; 2411…outer wall surface of first connecting flow channel; CV1…first pressure chamber; CV2…second pressure chamber; CV3…third pressure chamber; CV4…fourth pressure chamber; D4…fourth direction; D5…fifth direction; N…nozzle; Ln…nozzle array.

Claims

1. A liquid ejection head, characterized in that: have: a nozzle array, which is composed of a plurality of nozzles for ejecting liquid arranged in a first direction; a nozzle flow channel communicating with a predetermined nozzle among the plurality of nozzles and extending in a second direction intersecting the first direction; a first pressure chamber that applies pressure to the liquid; a second pressure chamber that applies pressure to the liquid and is adjacent to the first pressure chamber in the first direction; a first communication channel that connects the first pressure chamber and the nozzle channel and extends in a third direction orthogonal to both the first direction and the second direction; a second communication channel, which connects the second pressure chamber and the nozzle channel and extends in the third direction; When viewed from the second direction, the inner wall surface of the first communication flow channel on the second communication flow channel side includes a first inclined surface extending in a fourth direction intersecting both the first direction and the third direction.

2. The liquid ejection head according to claim 1, wherein When viewed from the second direction, the inner wall surface of the first communication flow channel has a first communication flow channel inner wall surface extending in the third direction. The first inclined surface is connected to the inner wall surface of the first communicating flow channel.

3. The liquid ejection head according to claim 2, wherein When viewed from the second direction, the inner wall surface of the second communication flow passage on the first communication flow passage side includes a second inclined surface extending in a fifth direction intersecting the first direction, the third direction, and the fourth direction.

4. The liquid ejection head according to claim 3, wherein The first inclined surface and the second inclined surface are connected to each other.

5. The liquid ejection head according to claim 4, wherein The inner wall surface of the nozzle flow channel has a nozzle flow channel inner wall surface, The nozzle flow channel inner wall surface extends in the second direction and is connected to the first inclined surface and the second inclined surface.

6. The liquid ejection head according to claim 2, wherein When viewed from the second direction, the inner wall surface of the second communication flow channel has a second communication flow channel inner wall surface extending in the third direction. The first inclined surface is connected to the inner wall surface of the first communication flow channel and the inner wall surface of the second communication flow channel.

7. The liquid ejecting head according to any one of claims 1 to 6, wherein: When viewed from the second direction, the outer wall surface of the first communication flow channel has a first communication flow channel outer wall surface extending in the third direction. When viewed from the second direction, the outer wall surface of the nozzle flow channel includes a first nozzle flow channel outer wall surface extending in the first direction and connected to the first communication flow channel outer wall surface.

8. The liquid ejection head according to claim 1, wherein Also features: a third pressure chamber, which applies pressure to the liquid and is located in the second direction relative to the first pressure chamber; a fourth pressure chamber that applies pressure to the liquid and is adjacent to the third pressure chamber in the first direction; a third communication flow channel, which connects the third pressure chamber and the nozzle flow channel and extends in the third direction; a fourth communication channel, which connects the fourth pressure chamber and the nozzle channel and extends in the third direction; When viewed from the second direction, an inner wall surface of the third communication flow passage on the fourth communication flow passage side includes a third inclined surface extending in the fourth direction.

9. The liquid ejection head according to claim 3, wherein When viewed from the second direction, the fourth direction and the fifth direction are inclined within a range of 30 degrees to 70 degrees with respect to the first direction.

10. The liquid ejection head according to claim 1, wherein A protective film is provided on the first inclined surface.

11. The liquid ejection head according to claim 10, wherein The protective film has a first layer and a second layer laminated on an outer surface of the first layer.

12. The liquid ejection head according to claim 11, wherein The first layer is composed of silicon oxide, The second layer is composed of tantalum oxide.

13. The liquid ejection head according to claim 11, wherein The first layer is composed of silicon oxide, The second layer is made of any one of hafnium oxide, diamond-like carbon, and aluminum oxide.

14. A liquid ejection device, characterized in that: have: The liquid ejection head according to any one of claims 1 to 13; A control unit controls the ejection operation from the liquid ejection head.

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