Liquid discharge head, liquid discharge apparatus, and method for manufacturing article

Abstract

To provide a technique advantageous for stabilizing liquid discharge.SOLUTION: A liquid discharge head comprises: two or more energy generating elements respectively arranged in two or more pressure chambers; two or more discharge nozzles which discharge a first liquid in the two or more pressure chambers; a common liquid chamber which communicates with the two or more pressure chambers and in which the first liquid is arranged; and a wall portion which is disposed in a gap with a space in which a second liquid of the same or different type as the first liquid is arranged, and allows a pressure wave to be transmitted from the first liquid in the common liquid chamber to the second liquid in the space.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection head, a liquid ejection device, and a method for manufacturing an article. [Background technology]

[0002] Generally, a liquid ejection head is configured to transfer energy to a liquid using an energy generating element to eject a predetermined amount of liquid from an ejection nozzle. For example, the liquid ejection head moves relative to a target object and ejects the liquid from the ejection nozzle, causing the liquid to land on the target object and drawing a structure on the target object.

[0003] The liquid ejection head has a plurality of ejection nozzles, a plurality of pressure chambers respectively connected to the ejection nozzles, and a common liquid chamber connected to the plurality of pressure chambers, and an energy generating element is disposed in each of the plurality of pressure chambers.

[0004] The following description focuses on the two energy elements and the two pressure chambers in which the two energy generating elements are respectively arranged in the liquid ejection head described above. When one of the two energy generating elements is driven, a pressure wave is generated in the liquid in one of the two pressure chambers. The pressure wave propagates to the liquid in the other of the two pressure chambers via the liquid in the common liquid chamber, which can cause the pressure of the liquid in the other pressure chamber to fluctuate. This phenomenon is called crosstalk.

[0005] When pressure crosstalk occurs, there is a risk that the ejection state of liquid from the ejection nozzle connected to the other pressure chamber will become unstable. For example, the volume, speed, and direction of droplets ejected from that ejection nozzle may change depending on the pressure propagated to the liquid in the other pressure chamber. Furthermore, for example, there is a risk that the meniscus, which is excessively raised by the vibration of the pressure wave, will spread around the opening of the ejection nozzle. If the meniscus spreads around the opening of the ejection nozzle, there is a risk that the ejection direction of the liquid will change or the liquid will not be ejected. If the ejection state of liquid from the ejection nozzle becomes unstable in this way, there is a risk that the density of the liquid will change or streaks will appear on the target object, resulting in a decrease in drawing accuracy.

[0006] The pressure waves mentioned above are classified into two types depending on the pressure propagation path. One type is a pressure wave that propagates directly from one pressure chamber where the pressure wave is generated to another pressure chamber adjacent to the pressure chamber, known as a direct propagation wave. The other type is a pressure wave that travels into the common liquid chamber, is reflected by the wall of the common liquid chamber, and propagates to the other pressure chamber, known as a wall reflection wave.

[0007] The strength of the direct propagation wave from one pressure chamber to the other depends on the distance between the two pressure chambers. Therefore, the greater the distance between the two pressure chambers, the smaller the strength of the direct propagation wave reaching the other pressure chamber.

[0008] Meanwhile, the strength of the wall-reflected wave that reaches one of the two pressure chambers depends on the reflection behavior of the pressure wave. Specifically, the magnitude of the pressure propagating to the other pressure chamber and the time at which the pressure peaks change depending on the distance from the start of the wall reflection to the arrival at the wall of the common liquid chamber and the reflection angle of the pressure wave at the wall of the common liquid chamber. Furthermore, because the wall-reflected wave propagates through the common liquid chamber while repeatedly reflecting multiple times at the wall of the common liquid chamber, the pressure is less likely to attenuate between the two distant pressure chambers, which can increase the strength of the wall-reflected wave that reaches the other pressure chamber.

[0009] Patent Document 1 discloses a technique for solving the problem of liquid ejection failure caused by waves reflected from the wall, in which a vibration absorber is provided on at least a part of the wall surface of the common liquid chamber. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-43252 Summary of the Invention [Problem to be solved by the invention]

[0011] In recent years, liquid ejection heads have been required to have even greater accuracy in the amount of liquid ejected and the accuracy of the liquid landing position, and there has also been a demand for further reduction in the occurrence of pressure crosstalk.

[0012] The present disclosure provides a technique that is advantageous for stabilizing the ejection of liquid. [Means for solving the problem]

[0013] One aspect of the present disclosure is a liquid ejection head comprising two or more energy generating elements respectively arranged in two or more pressure chambers; two or more ejection nozzles which respectively eject a first liquid from the two or more pressure chambers; a common liquid chamber which is connected to the two or more pressure chambers and in which the first liquid is arranged; and a wall portion which is arranged between a space in which a second liquid of the same or different type as the first liquid is arranged, and which is configured to transmit a pressure wave from the first liquid in the common liquid chamber to the second liquid in the space. [Effects of the Invention]

[0014] According to the present disclosure, a technique that is advantageous for stabilizing the ejection of liquid is provided. [Brief explanation of the drawings]

[0015] [Figure 1]1A and 1B are explanatory diagrams of a liquid ejection device according to a first embodiment. [Figure 2] FIG. 2 is a schematic perspective view illustrating a liquid flow path of the liquid ejection head according to the first embodiment. [Figure 3] 1 is a schematic cross-sectional view of a portion of a liquid ejection head according to a first embodiment. [Figure 4] 1A, 1B, and 1C are schematic cross-sectional views of a liquid ejection head according to a first embodiment. [Figure 5] 10(a) is a graph showing the relationship between the acoustic impedance ratio and the transmittance according to the first embodiment, and FIG. 10(b) is a graph showing the relationship between the thickness of the second member and the transmittance according to the first embodiment. [Figure 6] 10(a) and 10(b) are graphs showing the results of calculations by computer simulation according to the first embodiment. [Figure 7] 10(a), 10(b), and 10(c) are schematic cross-sectional views of a liquid ejection head according to a second embodiment. [Figure 8] FIG. 10 is a schematic perspective view illustrating a space including a liquid flow path of a liquid ejection head according to a third embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a portion of a liquid ejection head according to a third embodiment. [Figure 10] FIG. 10 is a schematic perspective view illustrating a space including a liquid flow path of a liquid ejection head according to a fourth embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a portion of a liquid ejection head according to a fourth embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a portion of a liquid ejection head according to a fourth embodiment. [Figure 13] 10A is a plan view schematically showing the positional relationship between the flow paths and the wall portions of a liquid ejection head according to a fourth embodiment, and FIG. 10B is a cross-sectional view of the liquid ejection head according to the fourth embodiment. [Figure 14] FIG. 11 is a plan view schematically showing the positional relationship between a flow path and a wall portion of a liquid ejection head according to a fifth embodiment. [Figure 15]10(a) is a schematic cross-sectional view of a wall portion according to the sixth embodiment, and (b) is a schematic perspective view of a wall portion according to a first modified example of the sixth embodiment. [Figure 16] (a) is a schematic plan view of a wall portion according to Modification 2 of the sixth embodiment. (b) is a schematic cross-sectional view of a wall portion according to Modification 2 of the sixth embodiment. (c) is a schematic plan view of a wall portion according to Modification 3 of the sixth embodiment. (d) is a schematic cross-sectional view of a wall portion according to Modification 3 of the sixth embodiment. (e) is a schematic plan view of a wall portion according to Modification 4 of the sixth embodiment. (f) is a schematic cross-sectional view of a wall portion according to Modification 4 of the sixth embodiment. [Figure 17] (a) is a schematic plan view of a wall portion according to Modification 5 of the sixth embodiment. (b) is a schematic cross-sectional view of a wall portion according to Modification 5 of the sixth embodiment. (c) is a schematic plan view of a wall portion according to Modification 6 of the sixth embodiment. (d) is a schematic cross-sectional view of a wall portion according to Modification 6 of the sixth embodiment. (e) is a schematic plan view of a wall portion according to Modification 7 of the sixth embodiment. (f) is a schematic cross-sectional view of a wall portion according to Modification 7 of the sixth embodiment. [Figure 18] FIG. 2 is an explanatory diagram of a liquid ejection head used in the examples. [Figure 19] FIG. 2 is an explanatory diagram of two nozzles used in the examples. [Figure 20] FIG. 1 is a diagram showing experimental conditions and experimental results of an example. [Figure 21] FIG. 1 is a diagram showing experimental conditions and experimental results of an example. [Figure 22] FIG. 1 is a diagram showing experimental conditions and experimental results of an example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are merely examples, and those skilled in the art can appropriately modify and implement the detailed configurations without departing from the spirit and scope of the present invention.

[0017] In the drawings referred to in the following description of the embodiments, elements denoted by the same reference numerals have the same functions unless otherwise specified. When a plurality of identical elements are arranged in a drawing, the assignment of the reference numerals and their explanation may be omitted. Furthermore, since the drawings may be represented schematically for the convenience of illustration and explanation, the shape, size, arrangement, etc. of elements depicted in the drawings may not strictly correspond to elements depicted in other drawings or to actual objects.

[0018] Furthermore, in this specification, the liquid handled by the liquid ejection device may be referred to as "ink," but the ink in the embodiments is not limited to a liquid for forming characters or images. For example, it may be a liquid containing a functional material for forming a functional thin film such as an electrode or an optical filter, or a functional element such as an organic electroluminescence (EL) element. Furthermore, the ejection and application of a liquid to an object may be referred to as "recording," but the recording in this context does not necessarily mean recording information such as characters or images. For example, it also includes applying a liquid to an object to manufacture an article such as a functional thin film, a functional element, or a three-dimensional object. Furthermore, the object to which the liquid is applied may be referred to as a "recording medium," but the recording medium is not limited to a medium for recording information such as characters or images, but also includes components that serve as the base material for manufacturing an article such as a functional thin film, a functional element, or a three-dimensional object.

[0019] In the following embodiments, directions are indicated by an XYZ coordinate system, which is a Cartesian coordinate system. The X, Y, and Z axes are perpendicular to one another. The direction of the X axis is also called the X direction, the direction of the Y axis is also called the Y direction, and the direction of the Z axis is also called the Z direction. A plane including the X and Y axes is also called an XY plane. The negative direction of the Z axis is also the direction of gravity. The X and Y directions are also horizontal directions.

[0020] [First embodiment] 1(a) and 1(b) are explanatory diagrams of a liquid ejection device 1 according to a first embodiment. Fig. 1(a) is a plan view of the liquid ejection device 1 as viewed in the direction of gravity, which is the negative direction of the Z axis. Fig. 1(b) is a side view of the liquid ejection device 1 as viewed in the positive direction of the Y axis.

[0021] The liquid (ink) used in the liquid ejection device 1 can be a variety of liquids, such as water-based ink, oil-based ink, ink containing an organic solvent (solvent-based ink), and ink with dispersed fine particles (fine particle dispersed ink).

[0022] The liquid ejection device 1 is used in part of a process for manufacturing an organic EL panel having an OLED (Organic Light Emitting Diode), which is an organic EL element. That is, the liquid ejection device 1 performs a coating process for coating a liquid onto a substrate S, which is an example of a target object (recording medium), to form a solution film on the substrate S. The liquid can be a solvent-based ink. Thereafter, a drying process for drying the solution film and a sintering process for sintering the dried film are performed to form a functional film (organic film) on the substrate S.

[0023] For example, a liquid such as a solvent-based ink is composed of a solution (ink) containing a solute and a solvent for forming an organic film. The solvent can exist in a liquid state under an environment of room temperature (25°C) and atmospheric pressure (1 atm). It is preferable that the solvent has a property that promotes evaporation in a reduced pressure environment lower than atmospheric pressure (1 atm). It is preferable that evaporation of the solvent is promoted at a temperature higher than room temperature (25°C), for example.

[0024] The solvent is preferably an organic solvent, such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, diethylene glycol monomethyl ether, cyclohexanone, N,N-dimethylisobutyramide, N-methylformamide, N-methylacetamide, N-diethylformamide, cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, 1,4-butanediol, propylene glycol ... Examples of the alkyl ether include ethylene glycol, hexylene glycol, propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, N-hexyl acetate, ethyl cellosolve acetate, and cyclohexylbenzene.

[0025] The organic film is an organic layer, such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, or an electron injection layer of an OLED. The production of an organic EL device includes the steps of forming each of the organic films, i.e., the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer, and the electron injection layer, on a substrate S. The solution film is applied to a required location on the substrate S by a liquid ejection apparatus 1 before a drying process.

[0026] The liquid ejection device 1 includes a liquid ejection head 3, a base 9, and a stage 10 that is disposed on the base 9 and holds a substrate S. The stage 10 is an example of a holding unit. A sub-scanning guide rail 7 extending in the Y direction is fixed to the base 9 via a support member 8. A main scanning guide rail 5 is mounted on the sub-scanning guide rail 7, and a main scanner 4 is mounted on the main scanning guide rail 5. The main scanning guide rail 5 is a carriage that is movable on the sub-scanning guide rail 7 in the Y direction. The main scanner 4 is movable on the main scanning guide rail 5 in the X direction.

[0027] A liquid discharge unit 2 is attached to the main scanner 4. By moving the main scanning guide rail 5 in the Y direction and the main scanner 4 in the X direction, the liquid discharge unit 2 can be freely scanned in the X and Y directions above the substrate S set on the stage 10.

[0028] The liquid ejection unit 2 is equipped with a liquid ejection head 3 capable of ejecting ink (liquid) toward the substrate S. The liquid ejection unit 2 is equipped with a flow path including a sub-tank for supplying ink to the liquid ejection head 3. An ink tank 51, which serves as a main tank, is installed on the base 9. The ink tank 51 stores ink to replenish the ink when the ink level in the sub-tank of the liquid ejection unit 2 becomes low, and the ink is supplied to the liquid ejection unit 2 through a connecting flow path 52. A flow path for waste liquid and a tank for waste liquid may also be provided as necessary.

[0029] 2 is a schematic perspective view illustrating a liquid flow path defined inside the liquid ejection head 3 according to the first embodiment. The liquid ejection head 3 is a non-circulation type liquid ejection head. As shown in FIG. 2, the liquid ejection head 3 includes a head main body 30 that defines a space including the liquid flow path, and five piezoelectric elements 18 that are arranged in the liquid flow path as two or more energy generating elements.

[0030] The head main body 30 is provided with five ejection nozzles 20 as two or more ejection nozzles. The five ejection nozzles 20 are arranged at intervals in the Y direction. The head main body 30 is also provided with five pressure chambers 19 as two or more pressure chambers. The five pressure chambers 19 are arranged at intervals in the Y direction. The head main body 30 is also provided with one common liquid chamber 16 that communicates with the five pressure chambers 19. The common liquid chamber 16 is an example of a first common liquid chamber. The common liquid chamber 16 holds liquid LIQ1 that is supplied to the five pressure chambers 19. The liquid LIQ1 is an example of a first liquid, and is the ink described above.

[0031] Each of the five discharge nozzles 20 is individually connected to a corresponding one of the five pressure chambers 19. That is, the five discharge nozzles 20 are connected to the five pressure chambers 19, respectively. The five discharge nozzles 20 are configured to discharge the liquid LIQ1 in each of the five pressure chambers 19. The liquid LIQ1 discharged from each discharge nozzle 20 lands on the substrate S and becomes a solution film.

[0032] A corresponding one of the five piezoelectric elements 18 is individually disposed in each of the five pressure chambers 19. That is, five piezoelectric elements 18 are disposed in the five pressure chambers 19, respectively.

[0033] Each of the five pressure chambers 19 is connected to one common liquid chamber 16 via a corresponding one of the five supply ports 17, and can receive a supply of ink (liquid) from the common liquid chamber 16. The supply port 17 is arranged at one end of the pressure chamber 19 in the longitudinal direction. The longitudinal direction of the pressure chamber 19 is the X direction in FIG. 2. The five supply ports 17 are arranged at intervals in a direction perpendicular to the longitudinal direction of the pressure chamber 19. The direction perpendicular to the longitudinal direction of the pressure chamber 19 is the Y direction in FIG. 2. However, the arrangement position and arrangement direction of the supply ports are not limited to the example shown in the figure.

[0034] Although the two or more discharge nozzles are five discharge nozzles 20 in the example described above, the number of discharge nozzles is not limited to five and may be any number as long as it is plural. Furthermore, while FIG. 2 exemplarily illustrates a case where there is one nozzle row, the present invention is not limited to this and there may be multiple nozzle rows. Furthermore, the number of pressure chambers 19 and the number of piezoelectric elements 18 may each be the same as the number of discharge nozzles 20.

[0035] For convenience, the illustration does not include the electrical circuitry and electrical wiring for driving the piezoelectric element 18. The energy generating element is not limited to the piezoelectric element 18. The energy generating element may be any other element that can impart ejection energy to the liquid, such as an electrothermal conversion element (heater).

[0036] The head main body 30 has a space 27. The space 27 is an example of a first space. A liquid LIQ2, which may be the same or different from the liquid LIQ1, is disposed in the space 27. The liquid LIQ2 is an example of a second liquid. In the first embodiment, the liquid LIQ2 is the same type of liquid as the liquid LIQ1, and is the ink described above. "Different" means that the components or concentrations of the liquids are different.

[0037] The head main body 30 also includes a wall portion 301 disposed between the common liquid chamber 16 and the space 27. In other words, the common liquid chamber 16 and the space 27 are adjacent to each other with the wall portion 301 sandwiched between them. In the first embodiment, the common liquid chamber 16 and the space 27 are adjacent to each other in the Z direction with the wall portion 301 sandwiched between them. The wall portion 301 is an example of a first wall portion.

[0038] The space 27 and the common liquid chamber 16 are in communication with each other via at least one communication hole 28 defined in the wall portion 301. The communication hole 28 is an example of a first communication hole. The communication hole 28 is a through-hole. A supply port 31 and a discharge port 32 defined in the head body 30 are connected to the space 27. The supply port 31 is connected to the connection flow path 52 shown in FIG. 1. In this way, the space 27 can be used as part of an ink distribution flow path.

[0039] With the above configuration, ink is supplied from the ink tank 51 to the space 27 via the connecting flow path 52 and the supply port 31. Air inside the space 27 is discharged from the outlet 32. The ink stored in the space 27 is supplied to the common liquid chamber 16 via the communication hole 28. The ink stored in the common liquid chamber 16 is supplied to each pressure chamber 19. When one of the multiple piezoelectric elements 18 that has received a command is driven, a portion of the ink stored in the pressure chamber 19 in which that piezoelectric element 18 is located is ejected from the ejection nozzle 20 connected to that pressure chamber 19.

[0040] In the first embodiment, the ink supplied from the ink tank 51 to the space 27 is the liquid LIQ2, and the ink supplied from the space 27 to the common liquid chamber 16 is the liquid LIQ1. In this way, the liquid LIQ2 is disposed in the space 27, and the liquid LIQ1 is disposed in the common liquid chamber 16.

[0041] FIG. 3 is a schematic cross-sectional view of a portion of the liquid ejection head 3 according to the first embodiment. FIGS. 4(a), 4(b), and 4(c) are schematic cross-sectional views of the liquid ejection head 3 according to the first embodiment. FIG. 3 shows a cross-section of the liquid ejection head 3 taken along a plane III-III' parallel to the XZ plane shown in FIG. 2, viewed in the positive direction of the Y axis. FIG. 4(a) shows a cross-section of the liquid ejection head 3 taken along a plane IVa-IVa' in FIG. 3, viewed in the negative direction of the Z axis. FIG. 4(b) shows a cross-section of the liquid ejection head 3 taken along a plane IVb-IVb' in FIG. 3, viewed in the negative direction of the Z axis. FIG. 4(c) shows a cross-section of the liquid ejection head 3 taken along a plane IVc-IVc' in FIG. 3, viewed in the negative direction of the Z axis.

[0042] The head main body 30 has a discharge surface 21 on which the five discharge nozzles 20 shown in FIG. 2 open. In the first embodiment, the head main body 30 is configured as a laminate of a first member 11, a second member 12, a third member 13, and a fourth member 14. The first member 11 has an orifice plate 111 and an element formation plate 112. The discharge surface 21 is included in the orifice plate 111. The discharge surface 21 is a plane (main surface) parallel to the XY plane and perpendicular to the Z direction. The height direction (thickness direction) of each of the members 11 to 14 is a direction perpendicular to the discharge surface 21 and parallel to the Z direction.

[0043] The orifice plate 111 has spaces that become ejection nozzles 20 and pressure chambers 19. The element forming plate 112 has wall surfaces that define the upper surfaces of the pressure chambers 19. Piezoelectric elements 18 are provided on the walls of the element forming plate 112 so as to face the pressure chambers 19. The element forming plate 112 also defines supply ports 17 that communicate between the pressure chambers 19 and the common liquid chamber 16. The orifice plate 111 and the element forming plate 112 are fixed together by, for example, adhesion or bonding. By fixing the orifice plate 111 and the element forming plate 112 together, pressure chambers 19 are defined inside the first member 11.

[0044] A third member 13 is disposed above the first member. A space that becomes a common liquid chamber 16 is formed in the third member 13. The third member 13, together with an element formation plate 112 and the second member 12, defines the common liquid chamber 16. The element formation plate 112 has a wall surface that defines the lower surface of the common liquid chamber 16, and the second member 12 has a wall surface that defines the upper surface of the common liquid chamber 16.

[0045] The material of the third member 13 is preferably a material with a linear expansion coefficient close to that of the first member 11, such as silicon (Si) or glass. Si and glass are suitable materials for the third member 13 because they are both less susceptible to dissolution by ink and less susceptible to clogging by ink. Depending on the properties of the ink, the third member 13 may have a base and a protective layer disposed on the surface of the base. The base is preferably silicon (Si) or glass, for example, and a protective layer may be disposed on the surface of the base. The protective layer is a layer that prevents the base from dissolving into the ink. The protective layer may be disposed on the side facing the common liquid chamber 16. The first member 11 and the third member 13 are preferably fixed together by, for example, adhesion or bonding.

[0046] The second member 12 is disposed above the third member 13. The second member 12 has the wall portion 301 described above. The wall portion 301 has the communication hole 28 described above. The wall portion 301 is disposed above the common liquid chamber 16.

[0047] The fourth member 14 is disposed above the second member 12. A hole that becomes the space 27 is formed in the fourth member 14. The second member 12 has a wall surface that defines the lower surface of the space 27. In this way, the space 27 faces the common liquid chamber 16 across the wall portion 301 of the second member 12.

[0048] As shown in Fig. 4(c), the second member 12 and the fourth member 14 are fixed by adhesion at an adhesive portion 29 shown in Fig. 4(c). The adhesive portion 29 is arranged to surround the space 27 so that the liquid LIQ2 does not leak from the space 27 to the outside.

[0049] The following description focuses on one of the two or more piezoelectric elements 18, one pressure chamber 19 in which that one piezoelectric element 18 is arranged, and an ejection nozzle 20 connected to that one pressure chamber 19. In the liquid ejection head 3, ink is supplied from the common liquid chamber 16 to the pressure chamber 19 via a supply port 17. With ink supplied to the pressure chamber 19, power is applied to the piezoelectric element 18 from a wiring board and electrical wiring (not shown). When power is applied, the piezoelectric element 18 deforms so as to bend toward the inside of the pressure chamber 19. The deformation of the piezoelectric element 18 reduces the volume of the pressure chamber 19, and pressure is applied to the ink within the pressure chamber 19. When pressure is applied to the ink within the pressure chamber 19, some of the ink is ejected from the ejection nozzle 20 as droplets. A pressure wave generated in the pressure chamber 19 when the droplets are ejected passes through the supply port 17 and propagates to the common liquid chamber 16.

[0050] The liquid ejection head 3 of the first embodiment is configured to reduce a phenomenon (crosstalk) in which pressure waves generated by the piezoelectric element 18 propagate to other pressure chambers 19 out of two or more pressure chambers 19 via the common liquid chamber 16. In other words, the wall portion 301 is configured to transmit pressure waves from the liquid LIQ1 in the common liquid chamber 16 to the liquid LIQ2 in the space 27.

[0051] This reduces the reflection of pressure waves on the wall portion 301, and among pressure crosstalk, it is possible to effectively reduce crosstalk due to wall-reflected waves. As a result, ink is stably ejected from each ejection nozzle 20, and the accuracy of the ink ejection amount ejected from each ejection nozzle 20 and the accuracy of the ink landing position are further improved.

[0052] Here, the transmittance of the pressure wave transmitted through the wall portion 301 from the liquid LIQ1 in the common liquid chamber 16 to the liquid LIQ2 in the space 27 is defined as T. From the viewpoint of reducing crosstalk, it is preferable that the transmittance T of the pressure wave transmitted through the wall portion 301 from the liquid LIQ1 in the common liquid chamber 16 to the liquid LIQ2 in the space 27 be 0.5 or more. Furthermore, from the viewpoint of further reducing crosstalk, it is preferable that the transmittance T of the pressure wave transmitted through the wall portion 301 from the liquid LIQ1 in the common liquid chamber 16 to the liquid LIQ2 in the space 27 be 0.8 or more.

[0053] Here, let Z1 be the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 16, Z2 be the acoustic impedance of the second member 12 (wall portion 301), and Z1' be the acoustic impedance of the liquid LIQ2 placed in the space 27. Also, let k2 be the wave number of the pressure wave passing through the wall portion 301, and L be the thickness of the wall portion 301 in the Z direction.

[0054] The transmittance T is calculated using the following formula (1).

number

[0055] That is, the transmittance T that satisfies the formula (1) is preferably 0.5 or more, and more preferably 0.8 or more.

[0056] Here, if the speed (sound speed) of the pressure wave passing through the wall portion 301 of the second member 12 is c2 and the angular frequency of the pressure wave is ω, then the wave number k2 is expressed as ω / c2. Furthermore, if the resonant frequency of one piezoelectric element 18 is f, then ω is expressed as 2πf. That is, the wave number k2 is expressed as 2πf / c2. Note that the resonant frequency f of the piezoelectric element 18 can be determined by applying a small AC voltage to the piezoelectric element 18, measuring the frequency dependency of the impedance, and judging from the peak of the measurement results.

[0057] The propagation speed of the pressure energy (pressure wave) generated by the piezoelectric element 18 varies depending on the medium. The reflectance and transmittance of the wall 301 also depend on the acoustic impedance of the medium, that is, the acoustic impedance Z1 of the liquid LIQ1 and the acoustic impedance Z1' of the liquid LIQ2.

[0058] Here, acoustic impedance is a numerical representation of the ease of propagation of sound (pressure waves), and can be calculated using the formula: density of the medium x speed of sound in the medium. The greater the difference in acoustic impedance, the greater the amount of reflection, and the smaller the difference, the greater the amount of transmission.

[0059] When the wave number k2 of the second member 12 satisfies k2L=nπ (n=1, 2, 3, ...), that is, when the thickness L satisfies L=nλ2 / 2, the transmittance T becomes maximum, where λ2 is the wavelength of the pressure wave that passes through the second member 12. In other words, when the thickness L of the second member 12 in the Z direction is an integer multiple of half the wavelength, the transmittance T becomes maximum.

[0060] Also, let ρ1 be the density of liquid LIQ1, c1 be the sound speed of the pressure wave propagating through liquid LIQ1, and ρ´ be the density of liquid LIQ2. 1´ Let the sound speed of the pressure wave propagating through the liquid LIQ2 be c´1. ρ1c1=ρ´ 1´ If c'1 is satisfied, the transmittance T is 1.

[0061] The liquid LIQ1 is a liquid that is ejected from the liquid ejection head 3 to form an image, etc., and can be a variety of liquids that are commonly used as ink, such as water-based ink, oil-based ink, solvent-based ink, and fine particle dispersion ink.

[0062] The acoustic impedance Z1 of the liquid LIQ1 is 1.0×10 6 [kg / m 2 / s] or more 1.7×10 6 [kg / m 2 / s].

[0063] Fig. 5(a) is a graph showing the relationship between the ratio (Z1 / Z1') of acoustic impedance Z1 to acoustic impedance Z1' according to the first embodiment and transmittance T. The graph shown in Fig. 5(a) shows transmittance T calculated using equation (1) under certain conditions.

[0064] The liquid LIQ2 disposed in the space 27 of the fourth member 14 may be the same or different liquid as the liquid LIQ1. The liquid LIQ2 may be any liquid that can attenuate the pressure energy that has passed through the wall portion 301. For example, the case where the second member 12 is a Si wafer with a thickness of 400 μm will be described. In this case, the acoustic impedance Z2 is 2.2×10 7 [kg / m 2 / s] and the density ρ2 is 2330 [kg / m 3 ] and the speed of sound c2 is 9620 [m / s].

[0065] When the resonant frequency f of the piezoelectric element 18 generated by driving the piezoelectric element 18 is 120 kHz, the angular frequency ω is 7.54×10 5 The acoustic impedance Z1', which satisfies the transmittance T calculated by the above formula (1) being 0.5 or more, is a value within the range of 0.5 to 5 times the acoustic impedance Z1, as is clear from FIG. 5(a). Note that although the resonant frequency f of the piezoelectric element 18 has been described as 120 kHz, variations exist. In other words, the resonant frequency f of the piezoelectric element 18 can be 100 kHz or more and 300 kHz or less.

[0066] The liquid LIQ2 may be the same type of liquid as the solvent contained in the liquid LIQ1, or a different type of liquid. The solvent contained in the liquid LIQ1 may be, for example, a liquid whose main component is water, an organic solvent, or oil. The liquid LIQ2 may be the same type of solvent as the solvent of the liquid LIQ1, but does not contain the solute contained in the liquid LIQ1. From the viewpoint of preventing contamination due to poor adhesion at the interface between the second member 12 and the fourth member 14, it is preferable that the liquid LIQ2 be the same type of liquid as the liquid LIQ1. In other words, it is preferable that Z1 = Z1'.

[0067] The second member 12 will now be described in detail. A part of the second member 12 is a wall portion 301, and the wall portion 301 is provided with a communication hole 28. In the following description, the second member 12 is a plate with a constant thickness, and the thickness of the wall portion 301 is assumed to be the same as the thickness of the second member 12.

[0068] Fig. 5(b) is a graph showing the relationship between the thickness L of the second member 12 according to the first embodiment and the transmittance T. The graph shown in Fig. 5(b) shows the transmittance T calculated using equation (1) under certain conditions.

[0069] The second member 12 is configured to contain, as a main component, a material having an acoustic impedance Z2 that allows the transmission of pressure energy generated by driving the piezoelectric element 18. The material having an acoustic impedance Z2 that allows the transmission of pressure energy generated by driving the piezoelectric element 18 is polyimide (PI), silicon (Si), or glass. In the first embodiment, the entire second member 12 is made of polyimide (PI), silicon (Si), or glass. Note that the second member 12 may have a base and a protective layer disposed on the surface of the base, and the base may be made of polyimide (PI), silicon (Si), or glass.

[0070] The transmittance T is calculated by applying the acoustic impedance Z2, which is the product of the density ρ2 of the second member 12 and the sound speed c2, the thickness L of the second member 12, and the wave number k2=ω / c2 of the second member 12 to equation (1).

[0071] In Figure 5(b), Z1 = Z1´ = 1.5 × 10 6 [kg / m 2 / s], ω = 7.54 × 10 5 10 shows an example in which the transmittance T is calculated when the second member 12 is made of polyimide (PI), silicon (Si), or glass, and the wavelength is expressed as [rad / s].

[0072] The smaller the acoustic impedance Z2, the higher the transmittance T. The range of thickness L of the member 12 for which the transmittance T is 0.5 or more is determined depending on the material selected for the second member 12. When the material of the second member 12 is Si or glass, the thickness L of the second member 12 is preferably 2 mm or less.

[0073] The material of the second member 12 is not limited to the above example. The material of the second member 12 may be any material that does not clog, deform, or dissolve due to the ink used. For example, the material of the second member 12 is preferably a resin such as acrylic resin, epoxy resin, polyimide, or polyethylene, or an inorganic material that is easily processed into a thin film, such as silicon or glass.

[0074] The material of the second member 12 may be a metal such as aluminum, stainless steel, or invar. As the stainless steel, stainless steel designated as SUS304 in JIS (Japanese Industrial Standards) or stainless steel designated as SUS316 in JIS is preferable.

[0075] Stainless steel designated as SUS304 in JIS is an austenitic stainless steel containing 0.08% or less carbon (C), 1.00% or less silicon (Si), 2.00% or less manganese (Mn), 0.045% or less phosphorus (P), 0.030% or less sulfur (S), 8.00% to 10.50% nickel (Ni), and 18.00% to 20.00% chromium (Cr).

[0076] Stainless steel designated as SUS316 in JIS is an austenitic stainless steel containing 0.08% or less carbon (C), 1.00% or less silicon (Si), 2.00% or less manganese (Mn), 0.045% or less phosphorus (P), 0.030% or less sulfur (S), 10.00% to 14.00% nickel (Ni), 16.00% to 18.00% chromium (Cr), and 2.00% to 3.00% molybdenum (Mo).

[0077] Hereinafter, stainless steel designated as SUS304 in JIS will be referred to as "SUS304," and stainless steel designated as SUS316 in JIS will be referred to as "SUS316."

[0078] As described above, the material of the second member 12 is preferably the above-mentioned resin, inorganic material, or metal, with polyimide, silicon, or glass being more preferred, and silicon or glass being even more preferred. The second member 12 may also be configured to include a base and a protective layer disposed on the surface of the base. In this case, the material of the base of the second member 12 is preferably the above-mentioned resin, inorganic material, or metal, with polyimide, silicon, or glass being more preferred, and silicon or glass being even more preferred. The material of the protective layer can be appropriately selected from the above-mentioned resin, inorganic material, and metal depending on the properties of the ink so as to prevent the base from dissolving into the ink.

[0079] Next, the fourth member 14 will be described in detail. The fourth member 14 defines a space 27 facing the common liquid chamber 16, sandwiching the second member 12. This has the effect that the pressure energy that has passed through the wall portion 301 of the second member 12 from the liquid LIQ1 in the common liquid chamber 16 to the liquid LIQ2 in the space 27 is attenuated in the liquid LIQ2 disposed in the space 27 while diffusing in the positive direction of the Z axis, which is the vertical direction.

[0080] Figures 6(a) and 6(b) are graphs showing the results of calculations by computer simulation according to the first embodiment. The height of the space 27 in the Z direction is designated as H. Figures 6(a) and 6(b) show graphs showing the relationship between the height H of the space 27 and the degree of reduction in pressure waves propagating between two adjacent discharge nozzles 20. Figure 6(a) shows the simulation results for a non-circulation type liquid discharge head, and Figure 6(b) shows the simulation results for a circulation type liquid discharge head.

[0081] The conditions used in the computer simulation are described below. The second member 12 was a 0.1 mm Si wafer. The fourth member 14 was made of SUS304. Using a model in which the liquid ejection head 3 had no space 27 (i.e., the height H of the space 27 was 0 mm) as a reference, we calculated the degree of reduction in pressure waves propagating between two ejection nozzles 20 when the height H of the space 27 was set to 0.2 mm, 0.5 mm, and 1 mm. The simulation results showed that the pressure was reduced by half when the height H was 0.2 mm. Therefore, the height H of the space 27 is preferably 0.2 mm or greater. This value may be the height of the liquid LIQ2, i.e., the liquid level, or the height H of the space 27 may be greater than the liquid level. Furthermore, a non-reactive gas such as air or N2 gas may be present above the surface of the liquid LIQ2.

[0082] Since the liquid LIQ2 is disposed in the space 27, a supply port 31 through which the liquid LIQ2 is introduced into the space 27 and a discharge port 32 for discharging air from the space 27 are connected, as shown in FIG. 2. The supply port 31 and the discharge port 32 are formed above the space 27. When the liquid LIQ2 disposed in the space 27 is the same type as the liquid LIQ2, ink is supplied to the space 27 from the ink tank 51 of FIG. 1 via the supply port 31, and ink is supplied from the space 27 to the common liquid chamber 16 via the communication hole 28. This configuration allows the liquid ejection head 3 to be made smaller. Note that the discharge port 32 may be omitted, and the supply port 31 may also serve as a discharge port for discharging air.

[0083] When the liquid ejection device 1 is applied to industrial or commercial applications, it is required to eject minute droplets with high precision. The ejected droplets may be a solution containing a solvent with high solubility, such as an organic solvent. The ink is also required to have high viscosity, which requires heating the liquid ejection head 3. Therefore, to prevent droplet deformation and positional deviation even in a heated environment, the fourth member 14 is preferably made of a material with good thermal conductivity and a linear expansion coefficient similar to that of the first member 11, the second member 12, and the third member 13.

[0084] Furthermore, the material of the fourth member 14 is preferably a material that is resistant to partial elution by the ink, depending on the properties of the ink. Therefore, the material of the fourth member 14 is preferably SUS304, SUS316, or Invar, and more preferably Invar. If even greater prevention of elution is required, the fourth member 14 may have a base and a protective layer disposed on the surface of the base. The material of the protective layer may be organic or inorganic.

[0085] The means for forming the space 27 in the fourth member 14 may be selected as appropriate depending on the material, such as cutting or laser processing. The second member 12 and the fourth member 14 are preferably fixed by adhesion or bonding. When the second member 12 and the fourth member 14 are fixed by adhesion, adhesive is applied to the second member 12 or the fourth member 14 using a dispenser or transfer, the second member 12 and the fourth member 14 are brought into contact with each other via the adhesive, and the adhesive is cured to form the adhesive portion 29 (FIG. 4(c)).

[0086] Furthermore, small fluctuations in the physical properties of the ink are required for fine particle dispersion inks and solvent-based inks used in industrial applications. In the first embodiment, the walls of the common liquid chamber 16, the space 27, and the like do not need to be made of porous materials, which reduces clogging of the walls with ink.

[0087] Furthermore, for all types of ink, it is possible to reduce the reflection of pressure waves at the wall portion 301 that defines the wall surface of the common liquid chamber 16. The pressure waves that pass through the wall portion 301 are attenuated by the liquid LIQ2 in the space 27. This reduces crosstalk caused by the waves reflected from the wall surface, and effectively reduces the occurrence of droplet ejection failures in the ejection nozzles 20. In this way, the first embodiment provides a technology that is advantageous for stabilizing the ejection of liquid.

[0088] [Second embodiment] A liquid ejection head according to the second embodiment will be described. Below, elements with the same reference numerals as those in the first embodiment will have substantially the same configurations and functions as those described in the first embodiment unless otherwise specified, and differences from the first embodiment will be mainly described.

[0089] Figures 7(a), 7(b), and 7(c) are schematic cross-sectional views of a liquid ejection head according to a second embodiment. Figure 7(a) shows a cross-section of the liquid ejection head taken along plane IVa-IVa' in Figure 3, viewed in the negative direction of the Z axis. Figure 7(b) shows a cross-section of the liquid ejection head taken along plane IVb-IVb' in Figure 3, viewed in the negative direction of the Z axis. Figure 7(c) shows a cross-section of the liquid ejection head taken along plane IVc-IVc' in Figure 3, viewed in the negative direction of the Z axis.

[0090] In the second embodiment, the common liquid chamber 16 and the space 27 do not communicate with each other, but are separated by a wall 301 of the second member 12. That is, the wall 301 functions as a partition. The supply port 31 passes through the fourth member 14 and the second member 12 and is directly connected to the common liquid chamber 16. That is, ink used to eject droplets is supplied to the common liquid chamber 16 from the ink tank 51 in FIG. 1 via the connection flow path 52 and the supply port 31.

[0091] Because the space 27 is isolated from the common liquid chamber 16 by the wall portion 301, the liquid LIQ2 in the space 27 is not used for ejecting droplets, and may be the same type of liquid as or different from the liquid LIQ1 in the common liquid chamber 16. The space 27 may be filled with the liquid LIQ2, or may be connected to a supply port (not shown) through which the liquid LIQ2 is supplied.

[0092] If the liquid LIQ2 in the space 27 is a different type of liquid from the liquid LIQ1 in the common liquid chamber 16, it is preferable that the space 27 and the supply port 31 are each surrounded by an adhesive portion 29, as shown in Figure 7(c), to prevent contamination, thereby ensuring that the space 27 and the supply port 31 are separated from each other.

[0093] Furthermore, when introducing liquid LIQ2 into space 27, an inlet (not shown) for introducing liquid LIQ2 into space 27 and an air outlet (not shown) for discharging air may be formed in the head body so as to be connected to space 27.

[0094] As described above, according to the second embodiment, similarly to the first embodiment, it is possible to reduce crosstalk caused by wall-reflected waves, and effectively reduce the occurrence of defective droplet ejection in the ejection nozzle 20. In this way, according to the first embodiment, a technique advantageous for stabilizing the ejection of liquid is provided.

[0095] [Third embodiment] A liquid ejection head according to the third embodiment will now be described. Below, elements that are given the same reference numerals as those in the first or second embodiment will have substantially the same configurations and functions as those described in the first or second embodiment unless otherwise specified, and differences from the first and second embodiments will be mainly described.

[0096] Fig. 8 is a schematic perspective view illustrating a space including a liquid flow path defined inside a liquid ejection head 3B according to the third embodiment. Fig. 9 is a cross-sectional view of a portion of a liquid ejection head 3B according to the third embodiment. Fig. 9 shows a cross-section of the liquid ejection head 3B along a IX-IX' plane parallel to the XZ plane shown in Fig. 8, viewed in the positive direction of the Y axis.

[0097] The liquid ejection head 3B is a circulation type liquid ejection head, and includes a head main body 30B that defines a space including a liquid flow path, and two or more piezoelectric elements .

[0098] The head main body 30B is equipped with two or more ejection nozzles 20. The two or more ejection nozzles 20 are arranged at intervals in the Y direction. The head main body 30B also is equipped with two or more pressure chambers 19. The two or more pressure chambers 19 are arranged at intervals in the Y direction. The head main body 30B also is equipped with one common liquid chamber 161 that communicates with the two or more pressure chambers 19, and one common liquid chamber 162 that communicates with the two or more pressure chambers 19. The common liquid chamber 161 is arranged to hold the liquid LIQ1 that is supplied to the two or more pressure chambers 19, and the common liquid chamber 162 is arranged to hold the liquid LIQ1 that is discharged from the two or more pressure chambers 19. The liquid LIQ1 is an example of a first liquid, such as ink. The common liquid chamber 161 is an example of a first common liquid chamber, and the common liquid chamber 162 is an example of a second common liquid chamber. The common liquid chamber 161 and the common liquid chamber 162 extend in the Y direction as the longitudinal direction, and are arranged at an interval from each other in the X direction.

[0099] Each of the two or more discharge nozzles 20 is individually connected to a corresponding one of the two or more pressure chambers 19. That is, the two or more discharge nozzles 20 are respectively connected to two or more pressure chambers 19. The two or more discharge nozzles 20 are configured to discharge the liquid LIQ1 in the two or more pressure chambers 19, respectively.

[0100] A corresponding one of the two or more piezoelectric elements 18 is individually disposed in each of the two or more pressure chambers 19. That is, two or more piezoelectric elements 18 are disposed in each of the two or more pressure chambers 19.

[0101] Each of the two or more pressure chambers 19 is in communication with one common liquid chamber 161 via a corresponding one of the two or more supply ports 171, and can receive a supply of ink (liquid) from the common liquid chamber 161. The supply port 171 is arranged at one end of the pressure chamber 19 in the longitudinal direction. The longitudinal direction of the pressure chamber 19 is the X direction in Figures 8 and 9. The two or more supply ports 171 are arranged at intervals in a direction perpendicular to the longitudinal direction of the pressure chamber 19. The direction perpendicular to the longitudinal direction of the pressure chamber 19 is the Y direction in Figures 8 and 9. However, the arrangement position and arrangement direction of the supply ports are not limited to the example shown in the figures.

[0102] Each of the two or more pressure chambers 19 is connected to one common liquid chamber 162 via a corresponding one of the two or more discharge ports 172, and is able to discharge ink (liquid) into the common liquid chamber 162. The discharge port 172 is arranged at the other end in the longitudinal direction of the pressure chamber 19. However, the arrangement position and arrangement direction of the discharge ports are not limited to the example shown in the figure.

[0103] 8 exemplarily illustrates a case where the number of discharge nozzles 20 is four, but this is not limited thereto, and the number of discharge nozzles 20 is any number equal to or greater than two. Also, while FIG. 8 exemplarily illustrates a case where there is one nozzle row, this is not limited thereto, and there may be multiple nozzle rows. Furthermore, the number of pressure chambers 19 and the number of piezoelectric elements 18 may each be the same as the number of discharge nozzles 20.

[0104] The head main body 30B has a space 271 and a space 272. The space 271 is an example of a first space, and the space 272 is an example of a second space. A liquid LIQ2, which may be the same as or different from the liquid LIQ1, is disposed in the space 271. A liquid LIQ3, which may be the same as or different from the liquid LIQ1, is disposed in the space 272. The liquid LIQ3 may be the same as or different from the liquid LIQ2. The liquid LIQ2 is an example of a second liquid, and the liquid LIQ3 is an example of a third liquid. In the third embodiment, the liquids LIQ1, LIQ2, and LIQ3 are all the same type of liquid, and may be the inks described above.

[0105] The spaces 271 and 272 extend with the Y direction as their longitudinal direction, and are spaced apart from each other in the X direction. The space 271 extends in the same direction as the extension direction of the common liquid chamber 161, and the space 272 extends in the same direction as the extension direction of the common liquid chamber 162. The space 271 and the common liquid chamber 161 are spaced apart in the Z direction, and the space 272 and the common liquid chamber 162 are spaced apart in the Z direction.

[0106] The head main body 30B also includes a wall portion 301 disposed between the common liquid chamber 161 and the space 271. In other words, the common liquid chamber 161 and the space 271 are adjacent to each other with the wall portion 301 sandwiched between them. In the third embodiment, the common liquid chamber 161 and the space 271 are adjacent to each other in the Z direction with the wall portion 301 sandwiched between them. The wall portion 301 is an example of a first wall portion.

[0107] The space 271 and the common liquid chamber 161 are in communication with each other through at least one communication hole 281 defined in the wall portion 301. The communication hole 281 is an example of a first communication hole. The communication hole 281 is a through-hole. A supply port 31 defined in the head main body 30B is connected to the space 271. The supply port 31 is connected to the connection flow path 52 shown in FIG. 1.

[0108] The head main body 30B also includes a wall portion 302 disposed between the common liquid chamber 162 and the space 272. In other words, the common liquid chamber 162 and the space 272 are adjacent to each other with the wall portion 302 sandwiched between them. In the third embodiment, the common liquid chamber 162 and the space 272 are adjacent to each other in the Z direction with the wall portion 302 sandwiched between them. The wall portion 302 is an example of a second wall portion.

[0109] The space 272 and the common liquid chamber 162 are in communication with each other through at least one communication hole 282 defined in the wall portion 302. The communication hole 282 is an example of a second communication hole. The communication hole 282 is a through hole. The space 272 is connected to an outlet 32 ​​defined in the head main body 30B.

[0110] With the above configuration, ink is supplied from the ink tank 51 to the space 271 via the connection flow path 52 and the supply port 31. The ink stored in the space 271 is supplied to the common liquid chamber 161 via the communication hole 281. The ink stored in the common liquid chamber 161 is supplied to each pressure chamber 19. When one of the multiple piezoelectric elements 18 that has received a command is driven, a portion of the ink stored in the pressure chamber 19 in which that piezoelectric element 18 is located is ejected from the ejection nozzle 20 connected to that pressure chamber 19.

[0111] The ink in each pressure chamber 19 is discharged into the common liquid chamber 162 via the communication hole 282. The ink disposed in the common liquid chamber 162 is returned to the ink tank 51 shown in FIG. 1 via the discharge port 32. In this way, in the third embodiment, ink is supplied to the space 271 from outside the liquid ejection head 3B, and ink is discharged from the space 272 to outside the liquid ejection head 3B, thereby circulating the ink within each pressure chamber 19.

[0112] In the third embodiment, the ink supplied from the ink tank 51 to the space 271 is liquid LIQ2, and the ink supplied from the space 271 to the common liquid chamber 161 is liquid LIQ1. Also, in the third embodiment, the ink discharged from each pressure chamber 19 to the common liquid chamber 162 is liquid LIQ1, and the ink discharged from the common liquid chamber 162 to the space 272 is liquid LIQ3. In this way, the liquid LIQ2 is disposed in the space 271, the liquid LIQ1 is disposed in the common liquid chamber 161, the liquid LIQ1 is disposed in the common liquid chamber 162, and the liquid LIQ3 is disposed in the space 272.

[0113] The head main body 30B has an ejection surface 21 on which two or more ejection nozzles 20 described above open. In the third embodiment, the head main body 30B is configured by a laminate of a first member 11, a second member 12, a third member 13, and a fourth member 14. The first member 11 has an orifice plate 111 and an element formation plate 112. The ejection surface 21 is included in the orifice plate 111. The height direction (thickness direction) of each of the members 11 to 14 is a direction perpendicular to the ejection surface 21 and a direction parallel to the Z direction.

[0114] In the third embodiment, the wall portions 301, 302 are part of the second member 12. That is, the second member 12 has the wall portions 301, 302. In other words, the wall portions 301, 302 are made of the same material. The wall portions 301, 302 have the same thickness. The thickness direction of the wall portions 301, 302 is the Z direction. Note that the materials and the like of the members 11 to 14 are the same as those described in the first embodiment, and will not be described here.

[0115] In the third embodiment, the head main body 30B has a wall portion 305. The wall portion 305 is an example of a fifth wall portion. The wall portion 305 is disposed between the space 271 and the space 272. The wall portion 305 is a partition wall that separates the space 271 and the space 272. In this way, the space 271 and the space 272 are separated by the wall portion 305. The wall portion 305 is configured to extend linearly along the Y direction, which is the longitudinal direction.

[0116] 9, the cross-sectional shape of wall 305 along the XZ plane is rectangular at any position in the Y direction of wall 305. Therefore, the width in the X direction of the cross-section is the same at any position in the Z direction, which is the height direction of wall 305.

[0117] 9, the wall portion 305 is preferably, but not limited to, a part of the fourth member 14. The wall portion 305 may be a part of the second member 12, or may be a member separate from the second member 12 and the fourth member 14.

[0118] The liquid ejection head 3B of the third embodiment is configured to reduce a phenomenon (crosstalk) in which pressure waves generated by the piezoelectric element 18 propagate to other pressure chambers 19 out of two or more pressure chambers 19 via at least one of the common liquid chamber 161 and the common liquid chamber 162. That is, the wall portion 301 is configured to transmit pressure waves from the liquid LIQ1 in the common liquid chamber 161 to the liquid LIQ2 in the space 271. The wall portion 302 is configured to transmit pressure waves from the liquid LIQ1 in the common liquid chamber 162 to the liquid LIQ3 in the space 272.

[0119] This reduces the reflection of pressure waves at the walls 301 and 302, and effectively reduces crosstalk due to wall-reflected waves among pressure crosstalk. As a result, ink is ejected stably from each ejection nozzle 20, and the accuracy of the ink ejection amount and the ink landing position ejected from each ejection nozzle 20 are further improved.

[0120] Here, the transmittance of the pressure wave that passes through the wall portion 301 from the liquid LIQ1 in the common liquid chamber 161 to the liquid LIQ2 in the space 271, and the transmittance of the pressure wave that passes through the wall portion 302 from the liquid LIQ1 in the common liquid chamber 162 to the liquid LIQ3 in the space 272 are each defined as T.

[0121] From the viewpoint of reducing crosstalk, each transmittance T is preferably 0.5 or more. Furthermore, from the viewpoint of further reducing crosstalk, each transmittance T is preferably 0.8 or more. In the third embodiment, each transmittance T also satisfies the formula (1) described in the first embodiment.

[0122] In this case, in equation (1), the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 161 is Z1, the acoustic impedance of the wall portion 301 is Z2, the acoustic impedance of the liquid LIQ2 placed in the space 271 is Z1', the wave number of the pressure wave passing through the wall portion 301 is k2, and the thickness of the wall portion 301 in the Z direction is L.

[0123] Furthermore, in equation (1), the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 162 is Z1, the acoustic impedance of the wall portion 302 is Z2, the acoustic impedance of the liquid LIQ3 placed in the space 272 is Z1', the wave number of the pressure wave passing through the wall portion 302 is k2, and the thickness of the wall portion 302 in the Z direction is L.

[0124] The suitable values ​​of the parameters shown in formula (1) are as explained in embodiment 1. The sizes of the spaces 271 and 272 are also the same as the size of the space 27 explained in embodiment 1, so explanations will be omitted.

[0125] In this way, the configuration of the non-circulation type liquid ejection head 3 described in the first embodiment can also be applied to the circulation type liquid ejection head 3B of the third embodiment. And, according to the third embodiment, as in the first embodiment, it is possible to reduce crosstalk caused by wall-reflected waves, and effectively reduce ejection failures of droplets from the ejection nozzles 20. In this way, according to the third embodiment, a technology advantageous for stabilizing the ejection of liquid is provided.

[0126] Although the case where wall portion 301, which is the first wall portion, and wall portion 302, which is the second wall portion, are made of the same material and have the same thickness has been described as an example, the present invention is not limited to this. For example, wall portion 301 and wall portion 302 may have different thicknesses, or wall portion 301 and wall portion 302 may be made of different materials.

[0127] Furthermore, the wall portion 305 is integral with the fourth member 14, but may be separate from the fourth member 14. Furthermore, the second member 12 and the wall portion 305 do not necessarily need to be in contact with each other, and an adhesive may be interposed between the second member 12 and the wall portion 305. Furthermore, if the liquids LIQ1 to LIQ3 are the same type of liquid, a gap may be left between the second member 12 and the wall portion 305 as long as there is no effect such as pressure loss.

[0128] 8, the wall portion 305 is located between at least one communication hole 281 provided in the second member 12. Each of the communication holes 281, 282 is preferably 50 μm or more away from the wall portion 305. This makes it possible to prevent the uncured adhesive from reaching each of the communication holes 281, 282 when the adhesive is cured to form an adhesive joint, even if the adhesive overflows from between the wall portion 305 and the second member 12.

[0129] [Fourth embodiment] A liquid ejection head according to the fourth embodiment will now be described. Below, elements that are given the same reference numerals as those in the first, second, or third embodiment will have substantially the same configurations and functions as those described in the first, second, or third embodiment unless otherwise specified, and differences from the first, second, and third embodiments will be mainly described.

[0130] Fig. 10 is a schematic perspective view illustrating a space including a liquid flow path defined inside a liquid ejection head 3C according to the fourth embodiment. Figs. 11 and 12 are cross-sectional views of a portion of a liquid ejection head 3C according to the fourth embodiment. Fig. 11 shows a cross section of the liquid ejection head 3C taken along a plane XI-XI' parallel to the XZ plane shown in Fig. 10, viewed in the positive direction of the Y axis. Fig. 12 shows a cross section of the liquid ejection head 3C taken along a plane XII-XII' parallel to the XZ plane shown in Fig. 10, viewed in the positive direction of the Y axis. The XI-XI' plane is an imaginary plane intersecting with a space 271, and the XII-XII' plane is an imaginary plane intersecting with a space 272.

[0131] The liquid ejection head 3C is a circulation type liquid ejection head, and includes a head main body 30C that defines a space including a liquid flow path, and a plurality of piezoelectric elements .

[0132] The head main body 30C includes a plurality of discharge nozzles 20. The discharge nozzles 20 are arranged in a matrix in the X and Y directions. That is, the discharge nozzles 20 include a plurality of nozzle rows, each consisting of two or more discharge nozzles 20 arranged in the Y direction. The nozzle rows are arranged at intervals in the X direction. In the example of FIG. 10, two nozzle rows are shown. The following description focuses on one nozzle row.

[0133] The two or more ejection nozzles 20 are arranged at intervals in the Y direction. The head main body 30C also has two or more pressure chambers 19. The two or more pressure chambers 19 are arranged at intervals in the Y direction. The head main body 30C also has one common liquid chamber 161 that communicates with the two or more pressure chambers 19, and one common liquid chamber 162 that communicates with the two or more pressure chambers 19. The common liquid chamber 161 contains the liquid LIQ1 that is supplied to the two or more pressure chambers 19, and the common liquid chamber 162 contains the liquid LIQ1 that is discharged from the two or more pressure chambers 19. The liquid LIQ1 is an example of a first liquid, such as ink. The common liquid chamber 161 is an example of a first common liquid chamber, and the common liquid chamber 162 is an example of a second common liquid chamber. The common liquid chamber 161 and the common liquid chamber 162 extend with the Y direction as their longitudinal direction, and are arranged at an interval from each other in the X direction.

[0134] Each of the two or more discharge nozzles 20 is individually connected to a corresponding one of the two or more pressure chambers 19. That is, the two or more discharge nozzles 20 are respectively connected to two or more pressure chambers 19. The two or more discharge nozzles 20 are configured to discharge the liquid LIQ1 in the two or more pressure chambers 19, respectively.

[0135] A corresponding one of the two or more piezoelectric elements 18 is individually disposed in each of the two or more pressure chambers 19. That is, two or more piezoelectric elements 18 are disposed in each of the two or more pressure chambers 19.

[0136] Each of the two or more pressure chambers 19 is in communication with one common liquid chamber 161 via a corresponding one of the two or more supply ports 171, and can receive a supply of ink (liquid) from the common liquid chamber 161. The supply port 171 is arranged at one end of the pressure chamber 19 in the longitudinal direction. The longitudinal direction of the pressure chamber 19 is the X direction in Figures 10, 11, and 12. The two or more supply ports 171 are arranged at intervals in a direction perpendicular to the longitudinal direction of the pressure chamber 19. The direction perpendicular to the longitudinal direction of the pressure chamber 19 is the Y direction in Figures 10, 11, and 12. However, the arrangement position and arrangement direction of the supply ports are not limited to the example shown in the figures.

[0137] Each of the two or more pressure chambers 19 is connected to one common liquid chamber 162 via a corresponding one of the two or more discharge ports 172, and is able to discharge ink (liquid) into the common liquid chamber 162. The discharge port 172 is arranged at the other end in the longitudinal direction of the pressure chamber 19. However, the arrangement position and arrangement direction of the discharge ports are not limited to the example shown in the figure.

[0138] 10 exemplarily illustrates a case where each nozzle row has four discharge nozzles 20, but this is not limited thereto, and the number of discharge nozzles 20 in each nozzle row may be any number equal to or greater than two. Also, while FIG. 10 exemplarily illustrates a case where there are two nozzle rows, this is not limited thereto, and there may be one nozzle row, or three or more nozzle rows. Furthermore, the number of pressure chambers 19 and the number of piezoelectric elements 18 may each be the same as the number of discharge nozzles 20.

[0139] The head main body 30C has a space 271 and a space 272. The space 271 is an example of a first space, and the space 272 is an example of a second space. A liquid LIQ2, which may be the same as or different from the liquid LIQ1, is disposed in the space 271. A liquid LIQ3, which may be the same as or different from the liquid LIQ1, is disposed in the space 272. The liquid LIQ3 may be the same as or different from the liquid LIQ2. The liquid LIQ2 is an example of a second liquid, and the liquid LIQ3 is an example of a third liquid. In the fourth embodiment, the liquids LIQ1, LIQ2, and LIQ3 are all the same type of liquid, and may be the inks described above.

[0140] The spaces 271 and 272 extend with the X direction as their longitudinal direction, and are spaced apart from each other in the Y direction. The space 271 extends in a direction perpendicular to (intersecting with) the extension direction of the common liquid chamber 161, and the space 272 extends in a direction perpendicular to (intersecting with) the extension direction of the common liquid chamber 162. The space 271 is spaced apart from the common liquid chamber 161 and the common liquid chamber 162 in the Z direction, and the space 272 is spaced apart from the common liquid chamber 161 and the common liquid chamber 162 in the Z direction. That is, when viewed in the Z direction, the space 271 intersects with the common liquid chamber 161 and the common liquid chamber 162, and the space 272 intersects with the common liquid chamber 161 and the common liquid chamber 162.

[0141] The head main body 30C also includes a wall portion 301 disposed between the common liquid chamber 161 and the space 271. In other words, the common liquid chamber 161 and the space 271 are adjacent to each other with the wall portion 301 sandwiched between them. In the fourth embodiment, the common liquid chamber 161 and the space 271 are adjacent to each other in the Z direction with the wall portion 301 sandwiched between them. The wall portion 301 is an example of a first wall portion.

[0142] The head main body 30C also includes a wall portion 302 disposed between the common liquid chamber 162 and the space 271. In other words, the common liquid chamber 162 and the space 271 are adjacent to each other with the wall portion 302 sandwiched between them. In the fourth embodiment, the common liquid chamber 162 and the space 271 are adjacent to each other in the Z direction with the wall portion 302 sandwiched between them. The wall portion 302 is an example of a second wall portion.

[0143] The head main body 30C also includes a wall portion 303 disposed between the common liquid chamber 161 and the space 272. In other words, the common liquid chamber 161 and the space 272 are adjacent to each other with the wall portion 303 sandwiched between them. In the fourth embodiment, the common liquid chamber 161 and the space 272 are adjacent to each other in the Z direction with the wall portion 303 sandwiched between them. The wall portion 303 is an example of a third wall portion.

[0144] The head main body 30C also includes a wall portion 304 disposed between the common liquid chamber 162 and the space 272. In other words, the common liquid chamber 162 and the space 272 are adjacent to each other with the wall portion 304 sandwiched between them. In the fourth embodiment, the common liquid chamber 162 and the space 272 are adjacent to each other in the Z direction with the wall portion 304 sandwiched between them. The wall portion 304 is an example of a fourth wall portion.

[0145] The space 271 and the common liquid chamber 161 are in communication with each other through at least one communication hole 281 defined in the wall portion 301. The communication hole 281 is an example of a first communication hole. The communication hole 281 is a through-hole. A supply port 31 defined in the head main body 30C is connected to the space 271. The supply port 31 is connected to the connection flow path 52 shown in FIG. 1.

[0146] The space 272 and the common liquid chamber 162 are in communication with each other through at least one communication hole 282 defined in the wall portion 304. The communication hole 282 is an example of a second communication hole. The communication hole 282 is a through hole. The space 272 is connected to an outlet 32 ​​defined in the head main body 30C.

[0147] With the above configuration, ink is supplied from the ink tank 51 to the space 271 via the connection flow path 52 and the supply port 31. The ink stored in the space 271 is supplied to the common liquid chamber 161 via the communication hole 281. The ink stored in the common liquid chamber 161 is supplied to each pressure chamber 19. When one of the multiple piezoelectric elements 18 that has received a command is driven, a portion of the ink stored in the pressure chamber 19 in which that piezoelectric element 18 is located is ejected from the ejection nozzle 20 connected to that pressure chamber 19.

[0148] The ink in each pressure chamber 19 is discharged into the common liquid chamber 162 via the communication hole 282. The ink disposed in the common liquid chamber 162 is returned to the ink tank 51 shown in FIG. 1 via the discharge port 32. In this way, in the fourth embodiment, ink is supplied to the space 271 from outside the liquid ejection head 3C, and ink is discharged from the space 272 to outside the liquid ejection head 3C, thereby circulating the ink within each pressure chamber 19.

[0149] In the fourth embodiment, the ink supplied from the ink tank 51 to the space 271 is liquid LIQ2, and the ink supplied from the space 271 to the common liquid chamber 161 is liquid LIQ1. Also, in the fourth embodiment, the ink discharged from each pressure chamber 19 to the common liquid chamber 162 is liquid LIQ1, and the ink discharged from the common liquid chamber 162 to the space 272 is liquid LIQ3. In this way, the liquid LIQ2 is disposed in the space 271, the liquid LIQ1 is disposed in the common liquid chamber 161, the liquid LIQ1 is disposed in the common liquid chamber 162, and the liquid LIQ3 is disposed in the space 272.

[0150] The head main body 30C has an ejection surface 21 on which the above-mentioned plurality of ejection nozzles 20 open. In the fourth embodiment, the head main body 30C is configured by a laminate of a first member 11, a second member 12, a third member 13, and a fourth member 14. The first member 11 has an orifice plate 111 and an element formation plate 112. The ejection surface 21 is included in the orifice plate 111. The height direction (thickness direction) of each of the members 11 to 14 is a direction perpendicular to the ejection surface 21 and a direction parallel to the Z direction.

[0151] In the fourth embodiment, the walls 301, 302, 303, and 304 are part of the second member 12. That is, the second member 12 has the walls 301, 302, 303, and 304. In other words, the walls 301, 302, 303, and 304 are made of the same material. The walls 301, 302, 303, and 304 have the same thickness. The thickness direction of the walls 301, 302, 303, and 304 is the Z direction. Note that the materials and the like of the members 11 to 14 are the same as those described in the first embodiment, and will not be described here.

[0152] In the fourth embodiment, the head main body 30C has a wall portion 305. The wall portion 305 is an example of a fifth wall portion. The wall portion 305 is disposed between the space 271 and the space 272. The wall portion 305 is a partition wall that separates the space 271 and the space 272. In this way, the space 271 and the space 272 are separated by the wall portion 305. The wall portion 305 is configured to extend linearly along the X direction, which is the longitudinal direction.

[0153] 11, the wall portion 305 is preferably, but not limited to, a part of the fourth member 14. The wall portion 305 may be a part of the second member 12, or may be a member separate from the second member 12 and the fourth member 14.

[0154] The liquid ejection head 3C of the fourth embodiment is configured to reduce a phenomenon (crosstalk) in which a pressure wave generated by the piezoelectric element 18 propagates to another of two or more pressure chambers 19 via at least one of the common liquid chamber 161 and the common liquid chamber 162. That is, the wall 301 is configured to transmit a pressure wave from the liquid LIQ1 in the common liquid chamber 161 to the liquid LIQ2 in the space 271. The wall 302 is configured to transmit a pressure wave from the liquid LIQ1 in the common liquid chamber 162 to the liquid LIQ2 in the space 271. The wall 303 is configured to transmit a pressure wave from the liquid LIQ1 in the common liquid chamber 161 to the liquid LIQ3 in the space 272. The wall 304 is configured to transmit a pressure wave from the liquid LIQ1 in the common liquid chamber 162 to the liquid LIQ3 in the space 272.

[0155] This reduces the reflection of pressure waves at the walls 301, 302, 303, and 304, and effectively reduces crosstalk caused by wall-reflected waves among pressure crosstalk. As a result, ink is ejected stably from each ejection nozzle 20, and the accuracy of the ink ejection amount and the ink landing position ejected from each ejection nozzle 20 are further improved.

[0156] Here, the transmittance of the pressure wave passing from the liquid LIQ1 in the common liquid chamber 161 to the liquid LIQ2 in the space 271 in the wall portion 301, the transmittance of the pressure wave passing from the liquid LIQ1 in the common liquid chamber 162 to the liquid LIQ2 in the space 271 in the wall portion 302, the transmittance of the pressure wave passing from the liquid LIQ1 in the common liquid chamber 161 to the liquid LIQ3 in the space 272 in the wall portion 303, and the transmittance of the pressure wave passing from the liquid LIQ1 in the common liquid chamber 162 to the liquid LIQ3 in the space 272 in the wall portion 304 are each defined as T.

[0157] From the viewpoint of reducing crosstalk, each transmittance T is preferably 0.5 or more. Furthermore, from the viewpoint of further reducing crosstalk, each transmittance T is preferably 0.8 or more. In the fourth embodiment, each transmittance T also satisfies the formula (1) described in the first embodiment.

[0158] In this case, in equation (1), the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 161 is Z1, the acoustic impedance of the wall portion 301 is Z2, the acoustic impedance of the liquid LIQ2 placed in the space 271 is Z1', the wave number of the pressure wave passing through the wall portion 301 is k2, and the thickness of the wall portion 301 in the Z direction is L.

[0159] Furthermore, in equation (1), the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 162 is Z1, the acoustic impedance of the wall portion 302 is Z2, the acoustic impedance of the liquid LIQ2 placed in the space 271 is Z1', the wave number of the pressure wave passing through the wall portion 302 is k2, and the thickness of the wall portion 302 in the Z direction is L.

[0160] Furthermore, in equation (1), the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 161 is Z1, the acoustic impedance of the wall portion 303 is Z2, the acoustic impedance of the liquid LIQ3 placed in the space 272 is Z1', the wave number of the pressure wave passing through the wall portion 303 is k2, and the thickness of the wall portion 303 in the Z direction is L.

[0161] Furthermore, in equation (1), the acoustic impedance of the liquid LIQ1 placed in the common liquid chamber 162 is Z1, the acoustic impedance of the wall portion 304 is Z2, the acoustic impedance of the liquid LIQ3 placed in the space 272 is Z1', the wave number of the pressure wave passing through the wall portion 304 is k2, and the thickness of the wall portion 304 in the Z direction is L.

[0162] The suitable values ​​of the parameters shown in formula (1) are as explained in embodiment 1. The sizes of the spaces 271 and 272 are also the same as the size of the space 27 explained in embodiment 1, so explanations will be omitted.

[0163] In this way, the configuration of the non-circulation type liquid ejection head 3 described in the first embodiment can also be applied to the circulation type liquid ejection head 3C of the fourth embodiment. And, according to the fourth embodiment, as in the first embodiment, it is possible to reduce crosstalk caused by wall-reflected waves, and effectively reduce the occurrence of droplet ejection failures in the ejection nozzles 20. In this way, according to the fourth embodiment, a technology advantageous for stabilizing the ejection of liquid is provided.

[0164] Fig. 13(a) is a plan view schematically showing the positional relationship between the flow paths defined inside a liquid ejection head 3C according to the fourth embodiment and a wall portion 305. Fig. 13(b) is a cross-sectional view of the liquid ejection head 3C according to the fourth embodiment. Fig. 13(b) shows a cross-section of the liquid ejection head 3C taken along plane XIIIB-XIIIB' parallel to the YZ plane shown in Fig. 13(a), viewed in the positive direction of the X axis.

[0165] 13(a), the wall portion 305 of the fourth member 14 is fixed to the second member 12 by adhesive at the adhesive portion 29. The wall portion 305 extends linearly along the X direction. As viewed in the Z direction, the common liquid chambers 161, 162 and the spaces 271, 272 are arranged perpendicular to each other, which makes it possible to arrange multiple nozzle rows at high density in the X direction and to make the liquid ejection head 3C more compact.

[0166] The wall 305 has a substantially rectangular parallelepiped shape with the X direction as the longitudinal direction. As shown in Fig. 13(b), the cross-sectional shape of the wall 305 along the YZ plane is rectangular at any position in the X direction of the wall 305. Therefore, the width in the Y direction of the cross-section is the same at any position in the Z direction, which is the height direction of the wall 305.

[0167] In the fourth embodiment, the first wall 301, the second wall 302, the third wall 303, and the fourth wall 304 are made of the same material and have the same thickness, but this is not limiting. For example, the thickness of any one of the walls 301 to 304 may be different from the thickness of any other one of the walls, or the material of any one of the walls may be different from the material of any other one of the walls.

[0168] Furthermore, the wall portion 305 is integral with the fourth member 14, but may be separate from the fourth member 14. Furthermore, the second member 12 and the wall portion 305 do not necessarily need to be in contact with each other, and an adhesive portion 29 may be interposed between the second member 12 and the wall portion 305. Furthermore, if the liquids LIQ1 to LIQ3 are the same type of liquid, a gap may be left between the second member 12 and the wall portion 305 as long as there is no effect from pressure loss or the like.

[0169] 10 , the wall portion 305 is located between at least one communication hole 281 provided in the second member 12. Each of the communication holes 281, 282 is preferably 50 μm or more away from the wall portion 305. This prevents the uncured adhesive from reaching the communication holes 281, 282 when the adhesive is cured to form the adhesive portion 29, even if the adhesive overflows from between the wall portion 305 and the second member 12.

[0170] [Fifth embodiment] A liquid ejection head according to the fifth embodiment will be described. Below, elements that are assigned the same reference symbols as those in the first, second, third, or fourth embodiment will have substantially the same configurations and functions as those described in the first, second, third, or fourth embodiment unless otherwise specified, and differences from the first, second, third, and fourth embodiments will be mainly described.

[0171] FIG. 14 is a plan view schematically showing the positional relationship between the flow paths defined inside the liquid ejection head 3D according to the fifth embodiment and the wall portion 305. As shown in FIG.

[0172] The liquid ejection head 3D of the fifth embodiment is a circulation type liquid ejection head, similar to the liquid ejection head 3C of the fourth embodiment. In the fourth embodiment, the wall portion 305 extends linearly along the X direction. In the fifth embodiment, the wall portion 305 extends in a zigzag pattern along the X direction.

[0173] When one discharge nozzle 20 is viewed in the Z direction, the wall portion 305 has a zigzag structure so that at least one of the two supply ports 171, 172 connected via the pressure chamber 19 overlaps with either the space 271, 272.

[0174] In the circulation-type liquid ejection head 3D, pressure energy is dispersed to two supply ports 171, 172 via a pressure chamber 19. At least one of the two supply ports 171, 172 overlaps with one of the spaces 271, 272, so pressure crosstalk can be effectively reduced.

[0175] [Sixth embodiment] A liquid ejection head according to the sixth embodiment will now be described. Below, elements that are given the same reference symbols as those in the first, second, third, fourth, or fifth embodiment will have substantially the same configurations and functions as those described in the first, second, third, fourth, or fifth embodiment unless otherwise specified, and differences from the first, second, third, fourth, and fifth embodiments will be mainly described.

[0176] In the third to fifth embodiments, the cross-sectional shape of the wall portion 305 is described as rectangular, but this is not limited thereto. The wall portion 305 is required to be formed in a shape that corresponds to the characteristics of the ink, such as the pressure loss of the ink, and the strength of the second member 12 or the second member 12 and the first member 11 to be adhered to. Under such constraints, it is preferable to reduce the occurrence of crosstalk caused by the wall portion 305, even in the wall portion 305.

[0177] In the sixth embodiment, a different form from the form of the wall portion 305 in the circulation-type liquid ejection head of the fourth embodiment will be described. FIG. 15(a) is a schematic cross-sectional view of the wall portion 305 according to the sixth embodiment. The wall portion 305 is an example of a fifth wall portion. Note that in FIG. 15(a), the thickness of the adhesive portion 29 in the Z direction is extremely small compared to the height of the wall portion 505 in the Z direction, but for convenience of explanation, it is illustrated as being thicker than it actually is. The width of the adhesive portion 29 in the Y direction is approximately the same as the width of the wall portion 305 in the Y direction.

[0178] 15(a), the longitudinal direction of the wall portion 305 is the X direction, the width direction of the wall portion 305 is the Y direction, and the height direction of the wall portion 305 is the Z direction. The Z direction is a direction perpendicular to the ejection surface 21 in FIGS. 11 and 12. The ejection surface 21 is a plane (main surface) parallel to the XY plane.

[0179] In at least a portion of the wall portion 305 in the X direction, and in the sixth embodiment, in the entire X direction, the area of ​​a first cross section S1 parallel to the XY plane at a first position P1 in the Z direction is preferably smaller than the area of ​​a second cross section S2 parallel to the XY plane at a second position P2 in the Z direction. As shown in FIG. 15(a), the first position P1 is closer to the ejection surface 21 (FIGS. 11 and 12) in the Z direction than the second position P2. This increases the area through which pressure waves pass (i.e., the wall portions 301 to 304) as viewed in the Z direction. This reduces crosstalk due to reflection of pressure waves at the wall portion 305.

[0180] Furthermore, in at least a portion of the wall portion 305 in the X direction, and in the sixth embodiment, the entire wall portion 305, the second position P2 is preferably the position farthest from the ejection surface 21 in the Z direction. Furthermore, the first position P1 is preferably the position closest to the ejection surface 21 in the Z direction. This increases the area through which the pressure waves pass (for example, the wall portions 301 to 304) as viewed in the Z direction. Therefore, crosstalk due to reflection of the pressure waves at the wall portion 305 is reduced.

[0181] Furthermore, at least a portion of the wall portion 305 in the X direction, and in the sixth embodiment, the entire wall portion 305, preferably has a width W1 in the Y direction at the first position P1 that is 1 to 10 times the pitch between the two or more discharge nozzles 20. This effectively reduces crosstalk caused by reflection of pressure waves at the wall portion 305. The width of the wall portion 305 in the Y direction is also the thickness of the wall portion 305 in the Y direction.

[0182] Furthermore, it is preferable that the height H2 of the wall portion 305 in the Z direction is 0.2 mm or more, which effectively reduces crosstalk caused by the reflection of pressure waves at the wall portion 305.

[0183] Furthermore, it is preferable that at least a portion of the wall 305 in the X direction, or in the sixth embodiment, the entire wall 305, has a tapered shape. That is, it is preferable that the width W2 in the Y direction of the wall 305 at the second position P2 is larger than the width W1 in the Y direction of the wall 305 at the first position P1. This reduces crosstalk and enables the wall 305 to maintain high strength.

[0184] It should be noted that the wall portion 305 is integral with the fourth member 14, but may be separate from the fourth member 14. Furthermore, the second member 12 and the wall portion 305 do not necessarily need to be in contact with each other, and an adhesive portion 29 may be interposed between the second member 12 and the wall portion 305. Furthermore, if the liquids LIQ1 to LIQ3 are the same type of liquid, a gap may be left between the second member 12 and the wall portion 305 as long as it does not cause any effects such as pressure loss.

[0185] 10 , the wall portion 305 is located between at least one communication hole 281 provided in the second member 12. Each of the communication holes 281, 282 is preferably 50 μm or more away from the wall portion 305. This prevents the uncured adhesive from reaching the communication holes 281, 282 when the adhesive is cured to form the adhesive portion 29, even if the adhesive overflows from between the wall portion 305 and the second member 12.

[0186] [Modification 1 of the Sixth Embodiment] Fig. 15(b) is a schematic perspective view of a wall portion 305 according to Modification 1 of the sixth embodiment. As shown in Fig. 15(b), a part of the wall portion 305 in the X direction may be tapered.

[0187] [Modification 2 of the Sixth Embodiment] FIG. 16(a) is a schematic plan view of a wall portion 305 according to Modification 2 of the sixth embodiment. FIG. 16(b) is a schematic cross-sectional view of the wall portion 305 according to Modification 2 of the sixth embodiment. FIG. 16(b) shows a cross section of the wall portion 305 along the AA' plane of FIG. 16(a) parallel to the YZ plane, viewed in the negative direction of the X axis. As shown in FIG. 16(b), the entire X direction of the wall portion 305 may include a tapered portion and a straight portion. The height in the Z direction of the tapered portion is defined as H1. The height in the Z direction of the entire wall portion 305 is defined as H2. The width in the Y direction of the wall portion 305 at the first position P1 is defined as W1. The width in the Y direction of the wall portion 305 at the second position P2 is defined as W2. 0

[0188] [Modification 3 of the Sixth Embodiment] FIG. 16(c) is a schematic plan view of a wall portion 305 according to Modification 3 of the sixth embodiment. FIG. 16(d) is a schematic cross-sectional view of a wall portion 305 according to Modification 3 of the sixth embodiment. FIG. 16(d) shows a cross section of the wall portion 305 along the AA' plane of FIG. 16(c), which is parallel to the YZ plane, viewed in the negative direction of the X axis. As shown in FIG. 16(d), a portion of the wall portion 305 in the X direction may include a tapered portion and a straight portion. The height of the tapered portion in the Z direction is defined as H1. The height of the entire wall portion 305 in the Z direction is defined as H2. The width of the wall portion 305 in the Y direction at the first position P1 is defined as W1. The width of the wall portion 305 in the Y direction at the second position P2 is defined as W2. 0

[0189] [Modification 4 of the Sixth Embodiment] ​​FIG. 16(e) is a schematic plan view of a wall portion 305 according to Modification 4 of the sixth embodiment. FIG. 16(f) is a schematic cross-sectional view of a wall portion 305 according to Modification 4 of the sixth embodiment. FIG. 16(f) shows a cross section of the wall portion 305 along the AA' plane of FIG. 16(e) parallel to the YZ plane, viewed in the negative direction of the X axis. As shown in FIG. 16(f), the entire X direction of the wall portion 305 may include a step shape. The height in the Z direction of the narrow portion of the step shape is defined as H1. The height in the Z direction of the entire wall portion 305 is defined as H2. The Y direction width of the wall portion 305 at the first position P1 is defined as W1. The Y direction width of the wall portion 305 at the second position P2 is defined as W2. 0

[0190] [Modification 5 of the Sixth Embodiment] FIG. 17(a) is a schematic plan view of a wall portion 305 according to Modification 5 of the sixth embodiment. FIG. 17(b) is a schematic cross-sectional view of the wall portion 305 according to Modification 5 of the sixth embodiment. FIG. 17(b) shows a cross section of the wall portion 305 along the AA' plane of FIG. 17(a) parallel to the YZ plane, viewed in the negative direction of the X axis. As shown in FIG. 17(b), a part of the wall portion 305 in the X direction may include a step shape. The height in the Z direction of the narrow part of the step shape is defined as H1. The height in the Z direction of the entire wall portion 305 is defined as H2. The width in the Y direction of the wall portion 305 at the first position P1 is defined as W1. The width in the Y direction of the wall portion 305 at the second position P2 is defined as W2. 0

[0191] [Modification 6 of the Sixth Embodiment] ​​FIG. 17(c) is a schematic plan view of a wall portion 305 according to Modification 6 of the sixth embodiment. FIG. 17(d) is a schematic cross-sectional view of a wall portion 305 according to Modification 6 of the sixth embodiment. FIG. 17(d) shows a cross section of the wall portion 305 along the AA' plane of FIG. 17(c), which is parallel to the YZ plane, viewed in the negative direction of the X axis. As shown in FIG. 17(d), the entire X direction of the wall portion 305 may include a concave shape. The height of the concave shape in the Z direction is defined as H1. The entire Z direction height of the wall portion 305 is defined as H2. The entire Y direction width of the wall portion 305 at the first position P1 is defined as W1. The Y direction width of the wall portion 305 at the second position P2 is defined as W2. 0

[0192] [Seventh Modification of the Sixth Embodiment] FIG. 17(e) is a schematic plan view of a wall portion 305 according to Modification 7 of the sixth embodiment. FIG. 17(f) is a schematic cross-sectional view of a wall portion 305 according to Modification 7 of the sixth embodiment. FIG. 17(f) shows a cross section of the wall portion 305 along the AA' plane of FIG. 17(e) parallel to the YZ plane, viewed in the negative direction of the X axis. As shown in FIG. 17(f), a portion of the wall portion 305 in the X direction may include a concave shape. The height of the concave shape in the Z direction is defined as H1. The overall height of the wall portion 305 in the Z direction is defined as H2. The overall width of the wall portion 305 in the Y direction at the first position P1 is defined as W1. The width of the wall portion 305 in the Y direction at the second position P2 is defined as W2. 0

[0193] The wall portion 305 of the third or fourth embodiment may have the same configuration as the wall portion 305 of any one of the sixth embodiment and the first to seventh modifications.

[0194] [Example] As examples, experiments were carried out in the following Examples 1 to 23 and Comparative Examples 1 to 4. The conditions and results of the experiments will be specifically described below.

[0195] 18 is an explanatory diagram of the liquid ejection head used in the example, in which two or more ejection nozzles 20 are arranged in a row in the Y direction. ​​

[0196] The method for evaluating the crosstalk in the experimental results will now be described. The evaluation of crosstalk was carried out using two nozzles out of the plurality of discharge nozzles 20. One of the two nozzles was designated as the first nozzle, and the other was designated as the second nozzle.

[0197] The amount of droplets ejected from the second nozzle was measured by how much it changed due to the influence of the pressure wave from the first nozzle, which ejected at a different timing. The ejection speed of each nozzle was evaluated by observing the flying droplets using jetXpert (ImageXpert).

[0198] First, the ejection speed v0 when the second nozzle was driven alone was evaluated using JetXpert. Next, the ejection speed v1 of the second nozzle was evaluated when droplets were ejected from the first nozzle while shifting the ejection timing. In this case, the first nozzle ejected before the second nozzle between 0 and 30 μs, and the ejection volume at the timing when the ejection speed of the second nozzle was the highest was v 1MAX The first nozzle was the nozzle immediately adjacent to the second nozzle. The two ejection velocities obtained and the following formula (2) were used to calculate the ejection amount fluctuation Δv due to crosstalk. Δv=v 1MAX -v0(2)

[0199] The conditions for evaluating the discharge volume are as follows. The position of the droplet was observed 300 μm below the nozzle tip, and the discharge volume was calculated from the droplet size in the image. The discharge frequency was 2 kHz.

[0200] Figure 19 is an explanatory diagram of two nozzles used in the example. In Figure 18, the discharge nozzle 20 located directly below the communication hole 28 is designated as Yn, the discharge nozzle 20 farthest from the communication hole 28 is designated as Ym, and the discharge nozzle 20 located midway between Yn and Ym is designated as Yl.

[0201] Crosstalk between the first and second nozzles that met the conditions shown in FIG. 19 was evaluated, and if the ejection volume of each second nozzle was within 10% of the average value, it was rated as A; if it was within 20%, it was rated as B; and if it was 20% or more, it was rated as C. FIGS. 20, 21, and 22 show the experimental conditions and results of the examples. FIGS. 20, 21, and 22 show the experimental results of Examples 1 to 23 and Comparative Examples 1 to 4, which are shown below. The transmittance T is a value calculated from the materials and physical properties of the components of the liquid ejection head. FIGS. 20, 21, and 22 show crosstalk evaluations A to C.

[0202] In addition, in Figures 20 and 21, "E+06" is "×10 6 " and "E+07" means "×10 7 " means.

[0203] Example 1 Example 1 according to the first embodiment will be described. A second member 12 was prepared, in which a communication hole 28 was formed in a 0.4 mm thick glass plate. A fourth member 14 was prepared by cutting SUS306 to form a 2 mm high space 27 and a supply port 31 from an ink tank. The first member 11, second member 12, third member 13, and fourth member 14 were bonded together with an epoxy adhesive to form a liquid ejection head 3. A solvent-based ink was used as the liquid LIQ1, and the same ink was also placed in the space 27. The crosstalk evaluation was A.

[0204] Example 2 Example 2 relating to the second embodiment will be described. A second member 12 was prepared, in which a communication hole 28 was formed in a 0.5 mm thick plate made of epoxy resin. A fourth member 14 was prepared by cutting stainless steel to form a space 27, a supply port 31 that does not communicate with the space 27 but is directly connected to the ink tank, and an inlet and air outlet above the space 27 for introducing liquid LIQ2. A liquid ejection head was otherwise fabricated in the same manner as described in Example 1. A water-based ink was used as liquid LIQ1, and a mixture of water contained in the water-based ink and isopropyl alcohol was placed in space 27 as liquid LIQ2. Crosstalk was evaluated as A.

[0205] Example 3 Example 3 of the third embodiment will be described. A second member 12 was prepared by forming communication holes 281 and 282 in a 0.4 mm thick Si wafer. A fourth member 14 was prepared by cutting Invar to form 4 mm-high spaces 271 and 272 and a supply port 31 from an ink tank. The third member 13, second member 12, and fourth member 14 were arranged so that the common liquid chamber 16 and spaces 271 and 272 were parallel to each other, and the third member 13, second member 12, and fourth member 14 were bonded together with an adhesive. A dispersed fine particle ink was used as the liquid LIQ1, and the same ink was also placed in the space 27. Because the viscosity of the ink was high, the liquid ejection head 3B was heated to 60°C to reduce the viscosity to the desired level.

[0206] Crosstalk was judged when the 4 mm high space 27 was filled with 100% ink and when it was filled with 30% ink. As a result, when the space 27 was filled with 100% ink, the crosstalk was judged as A. Also, when the space 27 was filled with 100% ink, the crosstalk was judged as B. Thus, even when the amount of ink was reduced to 30%, there was no significant effect on the crosstalk judgment.

[0207] In the long term, using less ink was able to suppress the settling of fine particles contained in the ink. Also, even when the liquid ejection head 3B was heated and ink was ejected, no misalignment between the components due to heating was observed.

[0208] Example 4 Example 4 relating to the fourth embodiment will be described. A second member 12 was prepared by forming communication holes 281 and 282 in a 0.2 mm thick Si wafer. A fourth member 14 was prepared by cutting Invar to form 3 mm high spaces 271 and 272 and a supply port 31 from an ink tank. The third member 13, second member 12, and fourth member 14 were arranged so that the longitudinal direction of the spaces 271 and 272 was perpendicular to the common liquid chamber 16, and the third member 13, second member 12, and fourth member 14 were bonded together with an adhesive. A solvent-based ink was used as the liquid LIQ1, and the same ink was also placed in the spaces 271 and 272. The crosstalk evaluation was A or B.

[0209] Furthermore, even when a solvent-based ink was used as the liquid LIQ1, the influence of eluates from the liquid ejection head 3B on the ink properties was hardly observed.

[0210] Example 5 Example 5 according to the fifth embodiment will be described. A fourth member 14 was prepared in which the wall portion 305 of the space 271 and the space 272 was processed into a zigzag shape so that the wall portion 305 overlapped directly above at least one of the supply ports 171 and 172 when viewed in the Z direction.

[0211] The third member 13, second member 12, and fourth member 14 were arranged so that the longitudinal direction of spaces 271 and 272 was perpendicular to the common liquid chamber 16, and the third member 13, second member 12, and fourth member 14 were bonded together with an adhesive. A solvent-based ink was used as the liquid LIQ1, and the same ink was also placed in spaces 271 and 272. The crosstalk was evaluated as A.

[0212] Furthermore, even when a solvent-based ink was used as the liquid LIQ1, the influence of the eluate from the liquid ejection head 3C on the ink properties was hardly observed.

[0213] (Examples 6 to 8) Examples 6 to 8 relating to the second modification of the sixth embodiment will be described. The fourth member 14 was prepared by cutting Invar to form the spaces 271 and 272 and the supply port 31 from the ink tank. The cross-sectional shape of the wall portion 305 of the fourth member 14 was tapered.

[0214] The height H2 of the wall portion 305 was set to 0.2 mm (Example 6), 1.5 mm (Example 7), and 3 mm (Example 8), respectively. The ratio of H1 / H2 was set to 50% (Example 6), 75% (Example 7), and 100% (Example 8), respectively. The width W1 of the wall portion 305 was set to 0.2 mm (Example 6), 0.5 mm (Example 7), and 0.8 mm (Example 8), respectively. The width W2 of the wall portion 305 was set to 0.4 mm (Example 6), 0.7 mm (Example 7), and 1 mm (Example 8), respectively.

[0215] Other than these, the same as in Example 4. The crosstalk was evaluated as A.

[0216] Examples 9 to 11 Examples 9 to 11 relating to the third modification of the sixth embodiment will be described. The fourth member 14 was prepared by cutting Invar to form the spaces 271 and 272 and the supply port 31 from the ink tank. The cross-sectional shape of part of the wall portion 305 of the fourth member 14 was tapered.

[0217] The height H2 of the wall portion 305 was set to 0.2 mm (Example 9), 1.5 mm (Example 10), and 3 mm (Example 11), respectively. The ratio of H1 / H2 was set to 50% (Example 9), 75% (Example 10), and 100% (Example 11), respectively. The width W1 of the wall portion 305 was set to 0.2 mm (Example 9), 0.5 mm (Example 10), and 0.8 mm (Example 11), respectively. The width W2 of the wall portion 305 was set to 0.4 mm (Example 9), 0.7 mm (Example 10), and 1 mm (Example 11), respectively.

[0218] Other than these, the same as in Example 4. The crosstalk was evaluated as A.

[0219] Examples 12 to 14 Examples 12 to 14 relating to the fourth modification of the sixth embodiment will be described. The fourth member 14 was prepared by cutting invar to form spaces 271 and 272 and a supply port 31 from an ink tank. The cross-sectional shape of a wall portion 305 of the fourth member 14 was formed into a convex shape facing the second member 12.

[0220] The height H2 of the wall portion 305 was set to 0.2 mm (Example 12), 1.5 mm (Example 13), and 3 mm (Example 14), respectively. The ratio of H1 / H2 was set to 50% (Example 12), 75% (Example 13), and 100% (Example 14), respectively. The width W1 of the wall portion 305 was set to 0.2 mm (Example 12), 0.5 mm (Example 13), and 0.8 mm (Example 14), respectively. The width W2 of the wall portion 305 was set to 0.4 mm (Example 12), 0.7 mm (Example 13), and 1 mm (Example 14), respectively.

[0221] Other than these, the same as in Example 4. The crosstalk was evaluated as A.

[0222] (Examples 15 to 17) Examples 15 to 17 relating to the fifth modification of the sixth embodiment will be described. The fourth member 14 was prepared by cutting Invar to form spaces 271 and 272 and a supply port 31 from an ink tank. A cross-sectional shape of a part of a wall portion 305 of the fourth member 14 was formed into a convex shape facing the second member 12.

[0223] The height H2 of the wall portion 305 was set to 0.2 mm (Example 15), 1.5 mm (Example 16), and 3 mm (Example 17), respectively. The ratio of H1 / H2 was set to 50% (Example 15), 75% (Example 16), and 100% (Example 17), respectively. The width W1 of the wall portion 305 was set to 0.2 mm (Example 15), 0.5 mm (Example 16), and 0.8 mm (Example 17), respectively. The width W2 of the wall portion 305 was set to 0.4 mm (Example 15), 0.7 mm (Example 16), and 1 mm (Example 17), respectively.

[0224] Other than these, the same as in Example 4. The crosstalk was evaluated as A.

[0225] (Examples 18 to 20) Examples 18 to 20 relating to the sixth modification of the sixth embodiment will be described. The fourth member 14 was prepared by cutting invar to form spaces 271 and 272 and a supply port 31 from an ink tank. The cross-sectional shape of a wall portion 305 of the fourth member 14 was made concave relative to the second member 12.

[0226] The height H2 of the wall portion 305 was set to 0.2 mm (Example 18), 1.5 mm (Example 19), and 3 mm (Example 20), respectively. The ratio of H1 / H2 was set to 50% (Example 18), 75% (Example 19), and 100% (Example 20), respectively. The width W1 of the wall portion 305 was set to 0.2 mm (Example 18), 0.5 mm (Example 19), and 0.8 mm (Example 20), respectively. The width W2 of the wall portion 305 was set to 0.4 mm (Example 18), 0.7 mm (Example 19), and 1 mm (Example 20), respectively.

[0227] Other than these, the same as in Example 4. The crosstalk was evaluated as A.

[0228] Examples 21 to 23 Examples 21 to 23 relating to Modification 7 of the sixth embodiment will be described. Spaces 271 and 272 and a supply port 31 from an ink tank were formed by cutting Invar to prepare the fourth member 14. A cross-sectional shape of a portion of a wall portion 305 of the fourth member 14 was formed into a concave shape relative to the second member 12.

[0229] The height H2 of the wall portion 305 was set to 0.2 mm (Example 21), 21 mm (Example 22), and 3 mm (Example 23), respectively. The ratio of H1 / H2 was set to 50% (Example 21), 75% (Example 22), and 100% (Example 23), respectively. The width W1 of the wall portion 305 was set to 0.2 mm (Example 21), 0.5 mm (Example 22), and 0.8 mm (Example 23), respectively. The width W2 of the wall portion 305 was set to 0.4 mm (Example 21), 0.7 mm (Example 22), and 1 mm (Example 23), respectively.

[0230] Other than these, the same as in Example 4. The crosstalk was evaluated as A.

[0231] (Comparative Example 1) The second member 12 used was 4 mm, as compared with Example 1. The crosstalk was evaluated as C.

[0232] (Comparative Example 2) The space 27 was omitted from Example 2. The crosstalk was evaluated as C.

[0233] (Comparative Example 3) In contrast to Example 3, the second member 12 used was 4 mm. Al was used for the fourth member 14. The crosstalk evaluation was rated C. Furthermore, as a result of long-term continuous operation in which ink was heated to eject and the heating was stopped when the ejection stopped, ink leakage due to peeling was observed at the interface between the second member 12 and the fourth member 14.

[0234] Comparative Example 4 The example used was one without the space 27, unlike Example 4. The crosstalk was evaluated as C.

[0235] <Embodiments of manufacturing methods of articles> In this embodiment, an article is manufactured using the liquid ejection device described above. The article may be an intermediate product or a final product. The article manufacturing method according to this embodiment is suitable for manufacturing an article such as an organic light-emitting diode (OLED) panel using an inkjet printing device. The article manufacturing method according to this embodiment includes a step (coating step) of depositing or applying a solution film (a solution containing a solute and a solvent for forming an organic film) on a substrate by a printing method using an inkjet printing device or the like to obtain a coated substrate. The method also includes a step (drying step) of drying the solution film on the coated substrate to obtain a dry substrate on which a dry film has been formed. Furthermore, this manufacturing method includes other well-known steps (such as baking, cooling, dehumidification, dry cleaning, electrode formation, and sealing film formation). The article manufacturing method according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0236] [Other variations] The present disclosure is not limited to the above-described embodiments, and many modifications of the embodiments are possible within the technical concept of the present disclosure. For example, at least two of the above-described embodiments and modifications may be combined. Furthermore, the effects described in the present embodiments are merely a list of the most preferable effects resulting from the embodiments of the present disclosure, and the effects of the embodiments of the present disclosure are not limited to those described in the present embodiments.

[0237] The above-described embodiments have been described as being applied to the production of displays including organic EL panels, but are not limited to this, and the above-described embodiments can also be applied to the production of displays including liquid crystal panels, for example.

[0238] The disclosure of the above embodiments includes the following sections.

[0239] (Section 1) two or more energy generating elements respectively disposed in two or more pressure chambers; two or more discharge nozzles that discharge the first liquid of the two or more pressure chambers, respectively; a wall portion disposed between a common liquid chamber communicating with the two or more pressure chambers and in which the first liquid is disposed, and a space in which a second liquid of the same type or a different type as the first liquid is disposed, the wall portion being configured to transmit a pressure wave from the first liquid in the common liquid chamber to the second liquid in the space; A liquid ejection head characterized by:

[0240] (Section 2) the transmittance of the pressure wave transmitted through the wall portion from the first liquid in the common liquid chamber to the second liquid in the space is 0.5 or more; Item 1. A liquid ejection head according to item 1.

[0241] (Section 3) the transmittance of the pressure wave transmitted through the wall portion from the first liquid in the common liquid chamber to the second liquid in the space is 0.8 or more; Item 1. A liquid ejection head according to item 1.

[0242] (Section 4) When the acoustic impedance of the first liquid is Z1, the acoustic impedance of the wall is Z2, the acoustic impedance of the second liquid is Z1', the wave number of the pressure wave passing through the wall is k2, the thickness of the wall is L, and the transmittance is T,

[0243]

number

[0244] (Section 5) The Z1 is 1.0 × 10 6 [kg / m 2 / s] or more 1.7×10 6 [kg / m 2 / s] or less, Item 5. A liquid ejection head according to item 4, characterized in that:

[0245] (Section 6) Z1' is 0.5 to 5 times the Z1. Item 6. A liquid ejection head according to item 4 or 5, characterized in that:

[0246] (Section 7) The height of the space is 0.2 mm or more. 7. The liquid ejection head according to any one of items 1 to 6, characterized in that:

[0247] (Section 8) the wall portion contains, as a main component, acrylic resin, epoxy resin, polyimide, polyethylene, silicon, glass, aluminum, stainless steel, or invar; 8. The liquid ejection head according to any one of items 1 to 7, characterized in that:

[0248] (Section 9) The thickness of the wall is 2 mm or less. 9. The liquid ejection head according to any one of items 1 to 8, characterized in that:

[0249] (Section 10) When the resonance frequency of any one of the two or more energy generating elements is f and the velocity of the pressure wave passing through the wall portion is c2, k2 is 2πf / c2, The frequency f is 100 kHz or more and 300 kHz or less. 7. The liquid ejection head according to any one of items 4 to 6, characterized in that

[0250] (Section 11) the common liquid chamber is a first common liquid chamber, the space is a first space, the wall portion is a first wall portion, a second wall portion that is disposed between a second common liquid chamber that is in communication with the two or more pressure chambers and in which the first liquid is disposed, and a second space in which a third liquid that is the same as or different from the first liquid is disposed, and that is configured to transmit a pressure wave from the first liquid in the second common liquid chamber to the third liquid in the second space; 11. The liquid ejection head according to any one of items 1 to 10, characterized in that:

[0251] (Section 12) the common liquid chamber is a first common liquid chamber, the wall portion is a first wall portion, a second wall portion that is disposed between a second common liquid chamber that is in communication with the two or more pressure chambers and in which the first liquid is disposed and the space, and that is configured to transmit a pressure wave from the first liquid in the second common liquid chamber to the second liquid in the space; 11. The liquid ejection head according to any one of items 1 to 10, characterized in that:

[0252] (Section 13) the space is a first space, a third wall portion disposed between the first common liquid chamber and a second space in which a third liquid, the same or different from the first liquid, is disposed, and configured to transmit a pressure wave from the first liquid in the first common liquid chamber to the third liquid in the second space; a fourth wall portion disposed between the second common liquid chamber and the second space, and configured to transmit a pressure wave from the first liquid in the second common liquid chamber to the third liquid in the second space; Item 13. A liquid ejection head according to item 12, characterized in that:

[0253] (Section 14) further comprising a fifth wall portion disposed between the first space and the second space; Item 14. A liquid ejection head according to item 11 or 13, characterized in that:

[0254] (Section 15) the first liquid, the second liquid, and the third liquid are inks that are the same type of liquid; the first common liquid chamber communicates with the first space through at least one first communication hole; the second common liquid chamber communicates with the second space through at least one second communication hole; Item 15. A liquid ejection head according to item 14, characterized in that:

[0255] (Section 16) the at least one first communication hole is spaced from the fifth wall portion by 50 μm or more, The at least one second communication hole is spaced 50 μm or more from the fifth wall portion. Item 16. A liquid ejection head according to item 15, characterized in that:

[0256] (Section 17) The ink is supplied to the first space from outside the liquid ejection head, The ink is discharged from the second space to the outside of the liquid ejection head. Item 17. A liquid ejection head according to item 15 or 16, characterized in that:

[0257] (Section 18) The fifth wall portion is a partition wall that separates the first space and the second space. 18. The liquid ejection head according to any one of items 14 to 17,

[0258] (Section 19) The fifth wall portion extends along a longitudinal direction perpendicular to a height direction perpendicular to a discharge surface on which the two or more discharge nozzles open. 19. The liquid ejection head according to any one of items 14 to 18, characterized in that

[0259] (Section 20) The fifth wall portion extends linearly or zigzag along the longitudinal direction. 20. A liquid ejection head according to item 19, characterized in that:

[0260] (Section 21) In at least a part of the longitudinal direction of the fifth wall portion, an area of ​​a first cross section parallel to the ejection surface at a first position in the height direction is smaller than an area of ​​a second cross section parallel to the ejection surface at a second position in the height direction; In the height direction, the first position is closer to the ejection surface than the second position. 21. A liquid ejection head according to item 19 or 20, characterized in that

[0261] (Section 22) In at least a part of the longitudinal direction of the fifth wall portion, the second position is a position farthest from the ejection surface in the height direction, and the first position is a position closest to the ejection surface in the height direction. 22. A liquid ejection head according to item 21, characterized in that:

[0262] (Section 23) At least a part of the fifth wall portion in the longitudinal direction includes a tapered shape or a stepped shape. 23. A liquid ejection head according to item 21 or 22, characterized in that:

[0263] (Section 24) In at least a part of the fifth wall portion in the longitudinal direction, the width of the fifth wall portion at the first position is 1 to 10 times the pitch of the two or more discharge nozzles. 24. The liquid ejection head according to any one of items 21 to 23,

[0264] (Section 25) The height of the fifth wall portion in the height direction is 0.2 mm or more. 25. The liquid ejection head according to any one of items 19 to 24,

[0265] (Section 26) a holder for holding an object; Item 26. The liquid ejection head according to any one of items 1 to 25, which ejects the first liquid onto the object held by the holding unit; A liquid ejection device comprising:

[0266] (Section 27) Item 27. A method for manufacturing an article, comprising discharging the first liquid onto an object using the liquid discharge device according to Item 26 to manufacture the article. [Explanation of symbols]

[0267] LIQ1...liquid (first liquid), LIQ2...liquid (second liquid), S...substrate (target object), 1...liquid ejection device, 3...liquid ejection head, 16...common liquid chamber, 18...piezoelectric element (energy generating element), 19...pressure chamber, 20...ejection nozzle, 21...ejection surface, 27...space, 301...wall

Claims

1. two or more energy generating elements respectively disposed in two or more pressure chambers; two or more discharge nozzles that discharge the first liquid of the two or more pressure chambers, respectively; a wall portion disposed between a common liquid chamber communicating with the two or more pressure chambers and in which the first liquid is disposed, and a space in which a second liquid of the same type or a different type as the first liquid is disposed, the wall portion being configured to transmit a pressure wave from the first liquid in the common liquid chamber to the second liquid in the space; A liquid ejection head characterized by:

2. the transmittance of the pressure wave transmitted through the wall portion from the first liquid in the common liquid chamber to the second liquid in the space is 0.5 or more; 2. The liquid ejection head according to claim 1.

3. the transmittance of the pressure wave transmitted through the wall portion from the first liquid in the common liquid chamber to the second liquid in the space is 0.8 or more; 2. The liquid ejection head according to claim 1.

4. The acoustic impedance of the first liquid is Z1, the acoustic impedance of the wall is Z2, the acoustic impedance of the second liquid is Z1', and the wave number of the pressure wave transmitted through the wall is k ２ , where L is the thickness of the wall portion and T is the transmittance, [Equation 1] The equation expressed by 3. The liquid ejection head according to claim 2.

5. The Z1 is 1.0 × 10 ６ [kg / m ２ / s] or more 1.7×10 ６ [kg / m ２ / s] or less, 5. The liquid ejection head according to claim 4.

6. Z1' is 0.5 to 5 times the Z1.

5. The liquid ejection head according to claim 4.

7. The height of the space is 0.2 mm or more.

2. The liquid ejection head according to claim 1.

8. the wall portion contains, as a main component, acrylic resin, epoxy resin, polyimide, polyethylene, silicon, glass, aluminum, stainless steel, or invar; 2. The liquid ejection head according to claim 1.

9. The thickness of the wall is 2 mm or less.

2. The liquid ejection head according to claim 1.

10. The resonance frequency of any one of the two or more energy generating elements is f, and the velocity of the pressure wave passing through the wall portion is c ２ When The k ２ is 2πf / c ２ and The f is 100 kHz or more and 300 kHz or less.

5. The liquid ejection head according to claim 4.

11. the common liquid chamber is a first common liquid chamber, the space is a first space, the wall portion is a first wall portion, a second wall portion disposed between a second common liquid chamber communicating with the two or more pressure chambers and in which the first liquid is disposed, and a second space in which a third liquid of the same type or a different type to the first liquid is disposed, the second wall portion being configured to transmit a pressure wave from the first liquid in the second common liquid chamber to the third liquid in the second space; 2. The liquid ejection head according to claim 1.

12. the common liquid chamber is a first common liquid chamber, the wall portion is a first wall portion, a second wall portion that is disposed between a second common liquid chamber that is in communication with the two or more pressure chambers and in which the first liquid is disposed and the space, and that is configured to transmit a pressure wave from the first liquid in the second common liquid chamber to the second liquid in the space; 2. The liquid ejection head according to claim 1.

13. the space is a first space, a third wall portion disposed between the first common liquid chamber and a second space in which a third liquid, the same or different from the first liquid, is disposed, and configured to transmit a pressure wave from the first liquid in the first common liquid chamber to the third liquid in the second space; a fourth wall portion disposed between the second common liquid chamber and the second space, and configured to transmit a pressure wave from the first liquid in the second common liquid chamber to the third liquid in the second space; 13. The liquid ejection head according to claim 12.

14. further comprising a fifth wall portion disposed between the first space and the second space; 12. The liquid ejection head according to claim 11.

15. the first liquid, the second liquid, and the third liquid are inks that are the same type of liquid; the first common liquid chamber communicates with the first space through at least one first communication hole; the second common liquid chamber communicates with the second space through at least one second communication hole; 15. The liquid ejection head according to claim 14.

16. the at least one first communication hole is spaced from the fifth wall portion by 50 μm or more, the at least one second communication hole is spaced from the fifth wall portion by 50 μm or more; 16. The liquid ejection head according to claim 15.

17. The ink is supplied to the first space from outside the liquid ejection head, The ink is discharged from the second space to the outside of the liquid ejection head.

16. The liquid ejection head according to claim 15.

18. The fifth wall portion is a partition wall that separates the first space and the second space.

15. The liquid ejection head according to claim 14.

19. the fifth wall portion extends along a longitudinal direction perpendicular to a height direction perpendicular to a discharge surface on which the two or more discharge nozzles open; 15. The liquid ejection head according to claim 14.

20. The fifth wall portion extends linearly or zigzag along the longitudinal direction.

20. The liquid ejection head according to claim 19.

21. In at least a part of the longitudinal direction of the fifth wall portion, an area of ​​a first cross section parallel to the ejection surface at a first position in the height direction is smaller than an area of ​​a second cross section parallel to the ejection surface at a second position in the height direction; In the height direction, the first position is closer to the ejection surface than the second position.

20. The liquid ejection head according to claim 19.

22. In at least a part of the fifth wall portion in the longitudinal direction, the second position is a position farthest from the ejection surface in the height direction, and the first position is a position closest to the ejection surface in the height direction.

22. The liquid ejection head according to claim 21.

23. At least a portion of the fifth wall portion in the longitudinal direction includes a tapered shape or a stepped shape.

22. The liquid ejection head according to claim 21.

24. a width of the fifth wall portion at the first position in at least a part of the longitudinal direction of the fifth wall portion is equal to or greater than 1 time and equal to or less than 10 times a pitch between the two or more discharge nozzles; 22. The liquid ejection head according to claim 21.

25. The height of the fifth wall portion in the height direction is 0.2 mm or more.

20. The liquid ejection head according to claim 19.

26. a holder for holding an object; a liquid ejection head according to claim 1 , which ejects the first liquid onto the object held by the holding section; A liquid ejection device comprising:

27. A method for manufacturing an article, comprising discharging the first liquid onto an object using the liquid discharge device according to claim 26.

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