Liquid ejection head, liquid ejection unit, and liquid ejection device

Abstract

To provide a liquid discharge head, a liquid discharge unit, and a liquid discharge apparatus capable of suppressing generation of cracks in a damper film.SOLUTION: A liquid discharge head includes: a damper film 66 bonded onto a common channel substrate being a channel substrate including a liquid channel substrate; and a damper frame substrate being a damper substrate which is bonded onto a surface opposite to a bond surface 66a bonded with the common channel substrate, of the damper film 66, and includes a recessed portion (void) 64 allowing the damper film 66 to exhibit a damper function. Therein, a cross-sectional shape of at least one of the bonding portion with a damper film 66, of the common channel substrate and a bonding portion with the damper film 66, of the damper frame substrate is a shape widening toward the end in which an angle formed with the damper film 66 is an acute angle.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, a liquid ejection unit, and an apparatus for ejecting liquid. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a liquid ejection head that ejects liquid from each nozzle by driving an electromechanical conversion element, the liquid being supplied from each pressure chamber through a liquid flow path.

[0003] Patent document 1 describes a liquid ejection head in which a damper film, which is a damper membrane for absorbing pressure fluctuations within a common liquid chamber, which is a liquid flow path, is joined to a frame member, which is a flow path substrate having a common liquid chamber, and a member, which is positioned on the damper chamber side opposite the common liquid chamber side across the damper film, and has an opening formed therein to allow deformation of the damper film. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a risk of cracks occurring in the damper film. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a liquid ejection head that drives an electromechanical conversion element to eject liquid in each pressure chamber supplied from a liquid flow path from each nozzle, the liquid ejection head comprising: a damper film bonded to a flow path substrate having the liquid flow path; and a damper substrate that is bonded to a surface of the damper film opposite to a surface bonded to the flow path substrate, and causes the damper film to exhibit a damping function, wherein in a cross-sectional view taken along a lamination direction in which the flow path substrate, the damper film, and the damper substrate are laminated, a bonding portion of the flow path substrate with the damper film is and, The damper substrate and the damper film are bonded to each other. Both, The damper membrane is characterized by a shape that widens toward the end so that the angle formed with the damper membrane is an acute angle. [Effects of the Invention]

[0006] According to the present invention, the occurrence of cracks in the damper film can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an explanatory perspective view of the appearance of the liquid ejection head according to the embodiment. [Figure 2] FIG. [Figure 3] FIG. 2 is a cross-sectional perspective view illustrating the liquid ejection head. [Figure 4] FIG. 2 is an exploded perspective view of the liquid ejection head excluding a frame member. [Figure 5] FIG. 2 is a cross-sectional perspective view illustrating a flow path portion of the liquid ejection head. [Figure 6] FIG. 2 is an enlarged perspective cross-sectional view of a flow path portion of the liquid ejection head. [Figure 7] FIG. 2 is a plan view illustrating a flow path portion of the liquid ejection head. [Figure 8] FIG. 2 is a schematic cross-sectional view showing the main part of the liquid ejection head 1. [Figure 9] FIG. 10 is an enlarged cross-sectional view of a main part of a conventional liquid ejection head. [Figure 10] FIG. 2 is an enlarged cross-sectional view of a main part of the liquid ejection head according to the embodiment. [Figure 11] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid ejection head according to a second embodiment. [Figure 12] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid ejection head according to a third embodiment. [Figure 13] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid ejection head according to a fourth embodiment. [Figure 14] FIG. 2 is an exploded perspective view illustrating the head module of the embodiment. [Figure 15] FIG. 2 is an exploded perspective explanatory view of the head module of the embodiment, as viewed from the nozzle surface side. [Figure 16] 1 is a schematic explanatory diagram of a printing apparatus that is an inkjet recording apparatus as an apparatus that ejects liquid in this embodiment. [Figure 17]FIG. 2 is an explanatory plan view of an example of a head unit of the printing apparatus according to the embodiment. [Figure 18] FIG. 2 is a plan view illustrating the main parts of the printing apparatus according to the embodiment. [Figure 19] FIG. 2 is a side view illustrating the main parts of the printing apparatus of the present embodiment. [Figure 20] FIG. 2 is a plan view illustrating a main part of the liquid ejection unit according to the embodiment. [Figure 21] FIG. 2 is a front view illustrating the liquid ejection unit of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment in which the present invention is applied to a liquid ejection head provided in an apparatus for ejecting liquid will be described below. FIG. 1 is an explanatory perspective view of the appearance of a liquid ejection head according to this embodiment. FIG. 2 is an exploded perspective view of the liquid ejection head. FIG. 3 is a cross-sectional perspective view of the liquid ejection head. FIG. 4 is an exploded perspective view of the liquid ejection head excluding the frame member. FIG. 5 is a cross-sectional perspective view of a flow path portion of the liquid ejection head. FIG. 6 is an enlarged perspective cross-sectional view of a flow path portion of the liquid ejection head. FIG. 7 is an explanatory plan view of the flow path portion of the liquid ejection head.

[0009] The liquid ejection head 1 of this embodiment includes a nozzle substrate 10, an actuator substrate 70, a common flow path substrate 50, a damper member 60, a frame member 80, and a substrate (flexible wiring substrate) 101 on which a drive circuit 102 is mounted. The actuator substrate 70 is composed of an individual flow path substrate 20 and a diaphragm 30. The nozzle substrate 10, the actuator substrate 70, the common flow path substrate 50, and the damper member 60 are all made of a single crystal Si wafer as a substrate material. Then, multiple chips (liquid ejection heads) are simultaneously fabricated on the Si wafer using microfabrication technology for MEMS and semiconductor devices, and the resulting chipped substrates are bonded together to form the liquid ejection head.

[0010] A plurality of nozzles 11 that eject liquid are provided on the nozzle substrate 10. The plurality of nozzles 11 are arranged in a two-dimensional matrix, and are aligned in three directions, a first direction F, a second direction S, and a third direction T, as shown in FIG.

[0011] The individual flow path substrate 20 has formed therein a plurality of pressure chambers (also referred to as individual liquid chambers) 21 each communicating with a plurality of nozzles 11, a plurality of individual supply flow paths 22 each communicating with the plurality of pressure chambers 21, and a plurality of individual recovery flow paths 23 each communicating with the plurality of pressure chambers 21. One pressure chamber 21 and the individual supply flow path 22 and individual recovery flow path 23 communicating therewith are collectively referred to as an individual flow path 25.

[0012] The vibration plate 30 forms a deformable vibration wall surface 31 of the pressure chamber 21, and a piezoelectric element 40 is integrally provided on the vibration wall surface 31. The vibration plate 30 also has a supply-side opening 32 that communicates with the individual supply flow path 22 and a recovery-side opening 33 that communicates with the individual recovery flow path 23. The piezoelectric element 40 is an electromechanical conversion element, and is pressure generating means that deforms the vibration wall surface 31 to pressurize the liquid in the pressure chamber 21.

[0013] The individual flow path substrate 20 and the diaphragm 30 are not limited to being separate components. For example, the individual flow path substrate 20 and the diaphragm 30 can be integrally formed from the same component using an SOI (Silicon On Insulator) substrate. That is, an SOI substrate having a silicon oxide film, a silicon layer, and a silicon oxide film formed in this order on a silicon substrate can be used, with the silicon substrate serving as the individual flow path substrate 20 and the diaphragm 30 being formed from the silicon oxide film, the silicon layer, and the silicon oxide film. In this configuration, the layered structure of the silicon oxide film, the silicon layer, and the silicon oxide film of the SOI substrate becomes the diaphragm 30. In this way, the diaphragm 30 includes one made of a material formed on the surface of the individual flow path substrate 20.

[0014] The common flow path substrate 50 forms common supply flow path tributaries 52, which are multiple common liquid chambers that communicate with two or more individual supply flow paths 22, and common recovery flow path tributaries 53, which are multiple common liquid chambers that communicate with two or more individual recovery flow paths 23, alternately adjacent to each other in the second direction S of the nozzle 11.

[0015] The common flow path substrate 50 has a through hole that serves as a supply port 54 connecting the supply side opening 32 of the individual supply flow path 22 and the common supply flow path tributary 52, and a through hole that serves as a recovery port 55 connecting the recovery side opening 33 of the individual recovery flow path 23 and the common recovery flow path tributary 53.

[0016] In addition, the common flow path substrate 50 forms one or more common supply flow path main streams 56 that communicate with multiple common supply flow path tributaries 52, and one or more common recovery flow path main streams 57 that communicate with multiple common recovery flow path tributaries 53.

[0017] The damper member 60 has a supply side damper 62 facing (opposing) the supply port 54 of the common supply flow path branch 52, and a recovery side damper 63 facing (opposing) the recovery port 55 of the common recovery flow path branch 53.

[0018] Here, the common supply flow path tributaries 52 and the common recovery flow path tributaries 53 are formed by sealing grooves arranged alternately on the common flow path substrate 50, which is the same member, with supply-side dampers 62 or recovery-side dampers 63 of the damper member 60. Note that it is preferable to use a metal thin film or an inorganic thin film that is resistant to organic solvents as the damper of the damper member 60. The thickness of the supply-side damper 62 and recovery-side damper 63 of the damper member 60 is preferably 10 μm or less.

[0019] The liquid ejection head 1 of this embodiment is provided with a damper member 60 that suppresses the influence (e.g., crosstalk) that pressure fluctuations in a liquid flow path (e.g., individual supply flow path 22) that occur when liquid is ejected from a nozzle 11 have on the liquid ejection from other nozzles 11. By allowing the damper member 60 to properly perform its damping function, it is possible to suppress crosstalk, in which vibrations (pressure fluctuations) during liquid ejection are propagated through the liquid and affect the liquid ejection of adjacent nozzles, and it is possible to stabilize the liquid ejection accuracy of each nozzle 11.

[0020] FIG. 8 is a schematic cross-sectional view showing the main part of the liquid ejection head 1. As shown in FIG. FIG. 8 is a cross-sectional view of the liquid ejection head 1 taken along the lamination direction in which the common flow path substrate 50, the damper film 66, and the damper frame substrate 65 are laminated. The damper member 60 has a damper film 66 made of a metal thin film or an inorganic thin film bonded to the common flow path substrate 50, and a damper frame substrate 65 as a damper holding substrate bonded to the damper film 66, which has a displacement space (void) formed therein to allow displacement of the damper film 66. An example of the damper film 66 as an inorganic thin film is a Si-based damper film with a three-layer structure in which a silicon nitride film is sandwiched between silicon oxide films. By forming the damper film in this laminated structure, it is possible to ensure the film rigidity required for the damper function and to easily obtain the functions required for a damper, such as preventing buckling.

[0021] The supply-side damper 62 and the recovery-side damper 63 of the damper member 60 are each composed of a recess (gap) 64 formed in a damper frame substrate 65 and a damper membrane 66 that covers the recess. The recess (gap) 64 is a displacement space that allows the damper membrane 66 to be displaced. The gaps 64 of the supply-side damper 62 and the recovery-side damper 63 are separated from each other by a gap partition 165. Furthermore, the common supply flow path branch 52 and the common recovery flow path branch 53 are separated from each other by a flow path partition 150.

[0022] FIG. 9 is an enlarged cross-sectional view of a main part of a conventional liquid ejection head taken in the stacking direction. As shown in FIG. 9 , the gap partition 165 of the damper member 60 and the flow path partition 150 of the common flow path substrate 50 are each bonded to a damper film 66 with an adhesive. Conventionally, the cross-sectional shape of the adhesive layer 65a is a rectangle whose length in the left-right direction in the figure is approximately the same as that of the gap partition 165. Therefore, the angle formed between the damper film 66 and the end face of the joint between the gap partition 165 and the damper film 66 is approximately a right angle. In addition, the adhesive layer 50a bonding the flow path partition 150 and the damper film 66 is also a rectangle whose length in the left-right direction in the figure is approximately the same as that of the flow path partition 150. Therefore, the angle formed between the damper film 66 and the end face of the joint between the flow path partition 150 and the damper film 66 is also approximately a right angle.

[0023] 9, cracks occurred at end A1 of the bonding surface 66a of the damper membrane 66 with the gap partition 165 and at end A2 of the bonding surface 66a with the flow path partition 150. This is thought to be because, in the conventional structure, during damping, the damper membrane 66 suddenly deforms from the ends A1 and A2 of the bonding surfaces 66a and 66b, causing stress concentration at the ends A1 and A2, which resulted in cracks at the ends A1 and A2.

[0024] FIG. 10 is an enlarged cross-sectional view of a main part of the liquid ejection head of this embodiment, taken along the lamination direction. 10, in this embodiment, the cross-sectional shape of the joint between the adhesive layer 65a and the end of the gap partition 165 on the damper membrane 66 side is flared so that the angle α1 formed with the damper membrane 66 is an acute angle. Similarly, the cross-sectional shape of the joint between the adhesive layer 50a and the end of the flow path partition 150 on the damper membrane 66 side is flared so that the angle α2 formed with the damper membrane 66 is an acute angle.

[0025] By making each joint have a flared shape that widens toward the damper membrane 66, the thickness of each joint gradually decreases toward the ends A1 and A2 of the joint surfaces 66a and 66b of the damper membrane 66. This allows the rigidity of each joint in the deformation direction of the damper membrane 66 (the vertical direction in the figure) to gradually decrease toward the ends A1 and A2 of the joint surfaces. As a result, when the damper membrane 66 is damped, the vicinity of the ends of the joint elastically deforms together with the damper membrane 66, and the entire vicinity of the ends A1 and A2 of the joints of the damper membrane with each partition wall 165 and 150 elastically deforms gently. This prevents stress from concentrating in the damper membrane 66 during damping, thereby preventing cracks from occurring in the damper membrane 66.

[0026] Furthermore, the smaller the angles α1, α2 formed by the joint and the damper membrane 66, the more gradual the decrease in rigidity of the joint, and the more gradual the deformation near the ends A1, A2 of the joint surface of the damper membrane during damping, which is preferable.

[0027] The flared shapes of the gap partitions 165 and the flow path partitions 150 on the damper membrane side can be formed by adjusting the etching and photolithography conditions. The shapes of the adhesive layers 65a, 50a are formed as follows. That is, the adhesive for bonding each partition 165, 150 to the damper membrane 66 is applied by thin-film transfer, but the bonding surfaces 66a, 66b of the damper membrane 66 to which the adhesive is applied are surface-treated to increase the wettability of the adhesive, making it easier for the adhesive to spread. This allows each adhesive layer 65a, 50a to have a flared shape with both ends gradually thinner toward the ends A1, A2 of the bonding surfaces.

[0028] Next, a driving durability test of the liquid ejection head will be described. For the drive durability test, examples and comparative examples were prepared which had different structures for the joints between the partition walls 165, 150 and the damper film 66, and the piezoelectric elements 40 were driven with a drive waveform of 30 V and 80 KHz. Discharge evaluation was then performed every 10 billion times, and heads which showed abnormal discharge were disassembled and the damper film 66 was observed with an IR microscope.

[0029] [Example 1] In Example 1, both the joint between the damper membrane 66 and the gap partition wall 165 and the damper membrane 66 and the flow path partition wall 150 shown in FIG. 10 have a cross-sectional divergent shape.

[0030] [Example 2] FIG. 11 is an enlarged cross-sectional view of a main part of a liquid ejection head according to a second embodiment. As shown in FIG. 11, in the second embodiment, only the joint between the flow path partition wall 150 and the damper membrane 66 has a cross section that diverges toward the end, and the rest of the structure is the same as that of the first embodiment.

[0031] [Example 3] FIG. 12 is an enlarged cross-sectional view of a main part of a liquid ejection head according to a third embodiment. As shown in FIG. 12, in the third embodiment, only the joint between the gap partition 165 and the damper membrane 66 has a cross section that flares outward, and the rest of the structure is the same as that of the first embodiment.

[0032] [Example 4] FIG. 13 is an enlarged cross-sectional view of a main part of a liquid ejection head according to a fourth embodiment. As shown in FIG. 13, in the fourth embodiment, the gap partition 165 is joined to the damper membrane 66 at a position shifted from the flow path partition 150, and the rest of the structure is the same as in the first embodiment.

[0033] [Comparative Example 1] Comparative Example 1 is the same as Example 1, except that both the angle between the junction of the damper membrane 66 and the gap partition 165 shown in Figure 9 and the angle between the junction of the damper membrane 66 and the flow path partition 150 are right angles.

[0034] For Comparative Example 1, an abnormality was found in the discharge in the 100 billionth discharge evaluation, and when the damper film 66 was observed with an IR microscope, cracks were confirmed in the damper film 66. On the other hand, for Examples 1 to 4 having a flared structure, no abnormality was found in the discharge in the 100 billionth discharge evaluation, and when the damper film 66 was observed with an IR microscope, no cracks were confirmed in the damper film 66.

[0035] From the above drive durability tests, it was found that the occurrence of cracks in the damper film 66 can be suppressed by making at least one of the joints between the common flow path substrate 50 and the damper film 66 and the joints between the damper frame substrate 65 and the damper film 66 have a cross-sectional flared shape.

[0036] When only one of the common flow path substrate 50 and the damper frame substrate 65 is formed in a flared shape as in Example 2 or Example 3, there is a risk of stress concentration occurring at the end of the joint surface that is not flared when the damper film 66 is significantly deformed. On the other hand, when both the common flow path substrate 50 and the damper frame substrate 65 are formed in a flared shape as in Example 1, there is an advantage in that stress concentration can be effectively suppressed even when the damper film 66 is significantly deformed. On the other hand, when only one of the common flow path substrate 50 and the damper frame substrate 65 is formed in a flared shape as in Example 2 or Example 3, there is an advantage as follows. That is, compared to Example 1, there is an advantage in that the increase in rigidity of the joint portion from the end of the joint surface can be made more gradual, and the joint surface of the damper film is more gently deformed.

[0037] Depending on the structure of the device, only the adhesive layers 50a and 65a may have a cross-sectional flared shape. The damper frame substrate 65 and the common flow path substrate 50 may be joined to the damper film 66 by a joining method other than adhesive.

[0038] Next, an example of a head module including the liquid ejection head 1 of this embodiment will be described with reference to FIGS. FIG. 14 is an exploded perspective view illustrating the head module of this embodiment. FIG. 15 is an exploded perspective explanatory view of the head module of this embodiment as seen from the nozzle surface side.

[0039] The head module 100 includes a liquid ejection head (hereinafter simply referred to as a "head") 1 that ejects liquid, a base member 103 that holds the multiple heads 1, and a cover member 113 that serves as nozzle covers 15 for the multiple heads 1. The head module 100 also includes a heat dissipation member 104, a manifold 105 that forms a flow path that supplies liquid to the multiple heads 1, a printed circuit board (PCB) 106 that connects to the flexible wiring member 101, and a module case 107.

[0040] Next, an example of a liquid ejection device according to the present invention will be described with reference to FIGS. FIG. 16 is a schematic explanatory diagram of a printing apparatus, which is an inkjet recording apparatus serving as a device for ejecting liquid in this embodiment. FIG. 17 is an explanatory plan view of an example of a head unit of a printing apparatus according to this embodiment.

[0041] A printing apparatus 500, which is an apparatus for ejecting this liquid, includes a carry-in means 501 that carries in a continuum 510, and a guide / conveyance means 503 that guides and conveys the continuum 510 carried in from the carry-in means 501 to a printing means 505. The printing apparatus 500 also includes a printing means 505 that ejects a liquid onto the continuum 510 to form an image, a drying means 507 that dries the continuum 510, and an ejection means 509 that ejects the continuum 510.

[0042] The continuous web 510 is sent out from a main winding roller 511 of the carry-in means 501, guided and conveyed by the rollers of the carry-in means 501, the guide and conveying means 503, the drying means 507, and the conveying means 509, and wound up by a winding roller 591 of the conveying means 509. In the printing means 505, the continuous web 510 is conveyed on a conveying guide member 559 opposite the head unit 550, and an image is printed by liquid ejected from the head unit 550.

[0043] In the printing device 500 of this embodiment, the head unit 550 includes the two head modules 100A and 100B according to this embodiment described above, mounted on a common base member 552.

[0044] When the direction in which the heads 1 are lined up in the direction perpendicular to the transport direction of the head modules 100A and 100B is defined as the head arrangement direction, the head arrays 1A1 and 1A2 of the head module 100A eject liquid of the same color. Similarly, the head arrays 1B1 and 1B2 of the head module 100A are paired, the head arrays 1C1 and 1C2 of the head module 100B are paired, and the head arrays 1D1 and 1D2 are paired, and each ejects liquid of the required color.

[0045] Next, another example of a printing apparatus as a liquid ejecting apparatus according to the present invention will be described with reference to FIGS. FIG. 18 is an explanatory plan view of the main parts of the printing apparatus of this example. FIG. 19 is an explanatory side view of the main part of the printing apparatus of this example.

[0046] The printing apparatus 500 of this example is a serial type apparatus, and a carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B to movably hold the carriage 403. The main scanning motor 405 then moves the carriage 403 back and forth in the main scanning direction via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0047] This carriage 403 is equipped with a liquid ejection unit 440 that integrates a head 1, which is a liquid ejection head according to the present invention, and a head tank 441. The head 1 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 1 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward. The liquid ejection head 1 is connected to a liquid circulation device, which circulates and supplies liquid of the required color.

[0048] The printing device 500 is equipped with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412. The transport belt 412 attracts the paper 410 and transports it at a position facing the head 1. The transport belt 412 is an endless belt that is stretched between a transport roller 413 and a tension roller 414. The attraction can be achieved by electrostatic attraction or air suction. The transport belt 412 moves in a circular motion in the sub-scanning direction as the transport roller 413 is rotationally driven by the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418.

[0049] Furthermore, a maintenance and recovery mechanism 420 that maintains and recovers the liquid ejection head 1 is disposed on one side of the carriage 403 in the main scanning direction, beside the conveyor belt 412. The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 that caps the nozzle surface of the head 1, a wiper member 422 that wipes the nozzle surface, and the like. The main scanning movement mechanism 493, maintenance and recovery mechanism 420, and conveyor mechanism 495 are attached to a housing that includes side plates 491A and 491B and a back plate 491C.

[0050] In the printing device 500 configured in this manner, the paper 410 is fed onto and adsorbed to the conveyor belt 412, and the paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412. Then, by driving the head 1 in accordance with an image signal while moving the carriage 403 in the main scanning direction, liquid is ejected onto the stationary paper 410 to form an image.

[0051] Next, another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 20 is a plan view illustrating the main parts of the liquid discharge unit of this example.

[0052] This liquid ejection unit 440 is composed of the components that make up the device that ejects the liquid, including a housing portion consisting of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a head 1.

[0053] It is also possible to configure a liquid discharge unit in which the above-described maintenance and recovery mechanism 420 is further attached to, for example, the side plate 491B of this liquid discharge unit 440.

[0054] Next, still another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 21 is an explanatory front view of the liquid discharge unit of this embodiment.

[0055] This liquid discharge unit 440 is composed of a head 1 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444 .

[0056] The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 for electrically connecting with the liquid ejection head 1 is provided on the upper part of the flow path part 444.

[0057] In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head. While not particularly limited, it is preferable that the viscosity of the liquid be 30 mPa·s or less at room temperature and pressure, or upon heating or cooling. More specifically, examples of such liquids include solvents such as water and organic solvents, colorants such as dyes and pigments, and functional materials such as polymerizable compounds, resins, and surfactants. Other examples include solutions, suspensions, and emulsions containing biocompatible materials such as DNA, amino acids, proteins, and calcium, and edible materials such as natural pigments. These liquids can be used in applications such as inkjet inks, surface treatment solutions, liquids for forming components of electronic devices and light-emitting elements, and resist patterns for electronic circuits, and liquid materials for 3D modeling.

[0058] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0059] A "liquid ejection unit" is a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to ejecting liquid. For example, a "liquid ejection unit" includes a liquid ejection head combined with at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0060] Here, "integrated" includes, for example, a liquid ejection head and a functional part or mechanism that are fixed to each other by fastening, bonding, engaging, etc., or one that is held movably relative to the other. The liquid ejection head, functional part, or mechanism may also be configured to be detachable from each other.

[0061] For example, some liquid ejection units have a liquid ejection head and a head tank integrated together, while others have a liquid ejection head and a head tank integrated together by being connected to each other by a tube, etc. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

[0062] Furthermore, there is a liquid ejection unit in which the liquid ejection head and the carriage are integrated.

[0063] In some liquid ejection units, the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together. In other liquid ejection units, the liquid ejection head, the carriage, and the main scanning movement mechanism are integrated together.

[0064] Furthermore, there is a liquid ejection unit in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which a liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

[0065] In some liquid ejection units, a tube is connected to a liquid ejection head equipped with a head tank or flow path components, integrating the liquid ejection head with a supply mechanism. Liquid is supplied from a liquid storage source to the liquid ejection head via this tube.

[0066] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0067] Here, the "liquid ejection unit" is described in combination with a liquid ejection head, but the "liquid ejection unit" also includes a head module or head unit that includes the liquid ejection head described above, and that integrates the functional components and mechanisms described above.

[0068] "Liquid ejection devices" include devices that are equipped with a liquid ejection head, a liquid ejection unit, a head module, a head unit, etc., and that eject liquid by driving the liquid ejection head. Liquid ejection devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0069] This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0070] For example, examples of "liquid ejecting devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0071] Furthermore, the term "liquid ejection device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0072] The above-mentioned "object onto which a liquid can adhere" means an object onto which a liquid can adhere at least temporarily, an object onto which the liquid can adhere and stick, an object onto which the liquid can penetrate, etc. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which a liquid can adhere.

[0073] The material of the "substance to which a liquid can adhere" may be any material to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0074] Furthermore, the "liquid ejection device" may be a device in which a liquid ejection head and an object onto which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which a liquid ejection head moves, and a line type device in which a liquid ejection head does not move.

[0075] Other examples of "liquid ejecting devices" include treatment liquid application devices that eject treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and spray granulation devices that spray a composition liquid in which raw materials are dispersed through a nozzle to granulate the raw material particles.

[0076] In the present application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

[0077] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) The liquid ejection head 1 ejects liquid such as ink in each pressure chamber 21 supplied from a liquid flow path from each nozzle 11 by driving an electromechanical conversion element such as a piezoelectric element 40, and is equipped with a damper film bonded to a flow path substrate such as a common flow path substrate 50 having a liquid flow path, and a damper substrate such as a damper frame substrate 65 bonded to the surface of the damper film opposite to the bonding surface with the flow path substrate, causing the damper film to exhibit a damping function, and in a cross-sectional view taken in the stacking direction in which the flow path substrate, damper film, and damper substrate are stacked, at least one of the bonding portion of the flow path substrate with the damper film and the bonding portion of the damper substrate with the damper film has a flared shape that forms an acute angle with the damper film. In the conventional example shown in Fig. 9, in which the joint portion of a damper substrate such as a damper frame substrate 65 to a damper film 66 and the joint portion of a flow path substrate such as a common flow path substrate 50 to a damper film 66 both have a cross-sectional shape that extends perpendicular to the damper film, the following problem occurs: When the damper film 66 is damped, the damper film 66 is suddenly deformed from the end A1 of the joint surface 66b of the damper film 66 with the damper substrate and the end A2 of the joint surface 66a of the damper film 66 with the flow path substrate as base points. As a result, stress is concentrated at the ends A1 and A2 of these joint surfaces of the damper film 66, causing cracks to occur in the damper film 66 over time. In contrast, in the first embodiment, the cross-sectional shape of at least one of the joint portion of the damper substrate to the damper membrane 66 and the joint portion of the flow path substrate to the damper membrane 66 is flared so that the angle with the damper membrane 66 is an acute angle. As a result, at least one of the joint portion of the damper substrate and the joint portion of the flow path substrate is shaped so that the thickness gradually decreases toward the ends A1 and A2 of the joint surfaces 66a and 66b of the damper membrane 66, thereby gradually weakening the rigidity of the joint toward the ends of the joint surfaces. As a result, during damping of the damper membrane, the joint portion elastically deforms together with the damper membrane, thereby easing deformation near the ends of the joint surfaces of the damper membrane 66. As a result, stress concentration in the damper membrane 66 during damping of the damper membrane can be suppressed, and cracks in the damper membrane 66 can be suppressed.

[0078] (Aspect 2) In embodiment 1, at least one of a flow path substrate such as a common flow path substrate 50 and a damper substrate such as a damper frame substrate 65 is bonded with an adhesive, and the cross-sectional shape of the adhesive layer formed from the adhesive is a flared shape that forms an acute angle with the damper film 66. This can prevent stress concentration from occurring in the damper film 66 .

[0079] (Aspect 3) In embodiment 1 or 2, the cross-sectional shapes of both the joint portion of the flow path substrate such as the common flow path substrate 50 and the joint portion of the damper substrate such as the damper frame substrate 65 are flared so that the angle formed with the damper film 66 is an acute angle. As a result, as described in the embodiment, stress concentration in the damper film 66 can be suppressed compared to when only one of the joints of the flow path substrate, such as the common flow path substrate 50, and the joints of the damper substrate, such as the damper frame substrate 65, has a cross-sectional flared shape.

[0080] (Aspect 4) The liquid ejection head 1 ejects liquid such as ink in each pressure chamber 21 supplied from a liquid flow path from each nozzle 11 by driving an electromechanical conversion element such as a piezoelectric element 40, and is equipped with a damper film bonded to a flow path substrate such as a common flow path substrate 50 having a liquid flow path, and a damper substrate such as a damper frame substrate 65 bonded to the surface of the damper film opposite to the bonding surface with the flow path substrate, causing the damper film to exhibit a damping function, and in a cross-sectional view taken in the stacking direction in which the flow path substrate, damper film, and damper substrate are stacked, the thickness of the end of the joint in the stacking direction of at least one of the joint between the flow path substrate and the damper film and the joint between the damper substrate and the damper film is thinner than the central part. This allows the rigidity of the ends of the joint (in this embodiment, ends A1 and A2 of the joint surface) to be weaker than that of the center portion, and when the damper membrane is damped, the joint elastically deforms together with the damper membrane, thereby easing deformation near the ends of the joint surface of the damper membrane 66. This makes it possible to prevent stress concentration in the damper membrane 66 when the damper membrane is damped, and to prevent cracks from occurring in the damper membrane 66.

[0081] (Aspect 5) In aspect 4, at least one of the joint between the damper film of a flow path substrate such as the common flow path substrate 50 and the damper film of a damper substrate such as the damper frame substrate 65 becomes thinner in thickness in the stacking direction toward the end of the joint. As a result, as described in the embodiment, deformation near the end of the bonding surface of the damper film 66 can be made gentler, stress concentration in the damper film 66 can be suppressed when the damper film is damped, and cracks can be suppressed from occurring in the damper film 66.

[0082] (Aspect 6) In any one of claims 1 to 5, the damper film 66 forms the wall surface of the common liquid chamber (in this embodiment, the common supply flow path branch 52 or the common recovery flow path branch 53) of the common flow path substrate 50, and has a gap portion such as a gap 64 that allows displacement of the damper film 66 at a location facing the common liquid chamber via the damper film 66 of a damper substrate such as a damper frame substrate 65. As explained in the embodiment, this allows pressure fluctuations in the liquid flow path that occur when liquid is ejected from the nozzles 11 to be absorbed by damping of the damper film 66, and makes it possible to suppress effects on other nozzles 11 (for example, crosstalk). This makes it possible to stabilize the liquid ejection accuracy of each nozzle 11.

[0083] (Aspect 7) The liquid ejection unit includes the liquid ejection head according to any one of the first to sixth aspects. This allows the liquid to be ejected satisfactorily over time.

[0084] (Aspect 8) A liquid ejection device includes the liquid ejection head according to any one of the first to sixth aspects or the liquid ejection unit according to the seventh aspect. This allows the liquid to be ejected satisfactorily over time. [Explanation of symbols]

[0085] 1: Liquid ejection head 10: Nozzle substrate 11: Nozzle 15: Nozzle cover 20: Flow path plate 21: Pressure chamber 22: Individual supply channel 23: Individual collection channel 25: Individual flow path 30: Vibration plate 31: Vibrating wall 32: Supply side opening 33: Collection side opening 40: Piezoelectric element 50: Common channel board 50a: Adhesive layer 52: Common supply channel tributary 53: Common collection channel tributary 54: Supply port 55: Collection port 56: Main common supply channel 57: Main common recovery channel 60: Damper member 62: Supply side damper 63: Recovery side damper 64: Recess (void) 65: Damper frame board 65a: Adhesive layer 66: Damper membrane 66a: Joint surface 66b: Joint surface 70: Actuator board 80: Frame member 100: Head module 101: Flexible wiring material 102: Drive circuit 103: Base member 104: Heat dissipation material 105: Manifold 107: Module case 113: Cover member 150: Flow path partition 165 :Void bulkhead 420: Maintenance and recovery mechanism 440: Liquid dispensing unit 441: Head Tank 500:Printing device 501: Means of transport 503: Guide and conveying means 505:Printing means 507 :Drying means 509:Export means 510: Continuum 511: Main winding roller 550: Head unit 552: Common base member 559: Transport guide member 591: Winding roller A1: Edge of the joint surface A2: Edge of the joint surface [Prior art documents] [Patent documents]

[0086] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-26912

Claims

1. A liquid ejection head that ejects liquid from each nozzle by driving an electromechanical conversion element, the liquid being supplied from each pressure chamber through a liquid flow path, a damper film joined to a flow path substrate having the liquid flow path; a damper substrate that is bonded to a surface of the damper film opposite to a bonding surface with the flow path substrate, and causes the damper film to exhibit a damping function; A liquid ejection head characterized in that, in a cross-sectional view taken in the stacking direction in which the flow path substrate, the damper film, and the damper substrate are stacked, both the joint portion between the flow path substrate and the damper film and the joint portion between the damper substrate and the damper film have a flared shape such that the angle between them and the damper film is an acute angle.

2. 2. The liquid ejection head according to claim 1, At least one of the flow path substrate and the damper substrate is bonded with an adhesive, The liquid ejection head is characterized in that the cross-sectional shape of the adhesive layer made of the adhesive is a shape that widens toward the end so that the angle formed with the damper film is an acute angle.

3. A liquid ejection head that ejects liquid from each nozzle by driving an electromechanical conversion element, the liquid being supplied from each pressure chamber through a liquid flow path, a damper film joined to a flow path substrate having the liquid flow path; a damper substrate that is bonded to a surface of the damper film opposite to a bonding surface with the flow path substrate, and causes the damper film to exhibit a damping function; A liquid ejection head characterized in that, in a cross-sectional view taken in the stacking direction in which the flow path substrate, the damper film, and the damper substrate are stacked, the thickness in the stacking direction at both the joint portion between the flow path substrate and the damper film and the joint portion between the damper substrate and the damper film at the ends of the joint is thinner than at the center.

4. 4. The liquid ejection head according to claim 3, A liquid ejection head characterized in that at least one of the joint portion between the flow path substrate and the damper film and the joint portion between the damper substrate and the damper film has a thickness in the stacking direction that becomes thinner toward the end of the joint portion.

5. 5. The liquid ejection head according to claim 1, the damper film forms a wall surface of a common liquid chamber of the flow path substrate; The liquid ejection head further comprises a gap portion for allowing displacement of the damper film at a location of the damper substrate facing the common liquid chamber with the damper film interposed therebetween.

6. A liquid ejection unit comprising the liquid ejection head according to claim 1 .

7. 7. A liquid ejection device comprising: a liquid ejection head according to claim 1; or a liquid ejection unit according to claim 6.

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