Liquid discharge head and liquid discharge apparatus

Abstract

The liquid discharge head includes a plurality of nozzles, a plurality of pressure chambers, a plurality of actuators, a common liquid chamber, and a damper. The plurality of nozzles discharge the liquid. A plurality of pressure chambers are respectively in communication with a corresponding one of the plurality of nozzles. A plurality of actuators are provided on nozzle communication walls of corresponding pressure chambers among the plurality of pressure chambers, respectively, and pressurize liquid in the corresponding pressure chambers among the plurality of pressure chambers. A common liquid chamber is in communication with the plurality of pressure chambers. A damper is provided at a position facing an opening portion of the plurality of pressure chambers, the opening portion facing the common liquid chamber. The minimum distance between the buffer and each opening part is equal to or smaller than the distance between the centers of two adjacent opening parts.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a liquid discharge head and a liquid discharge apparatus. Background Art

[0002] A liquid discharge head is known, which includes a plurality of nozzles for discharging liquid, a plurality of pressure chambers respectively connected to the above-mentioned plurality of nozzles, a plurality of actuators respectively arranged on the nozzle connecting walls of the above-mentioned plurality of pressure chambers for pressurizing the liquid in each pressure chamber, and a common liquid chamber connected to the above-mentioned plurality of pressure chambers.

[0003] For example, Patent Document 1 discloses a liquid discharge head comprising: a nozzle plate (nozzle connecting wall) on which a plurality of nozzles and an actuator are formed; a substrate on which a plurality of cylindrical pressure chambers respectively connected to the plurality of nozzles are formed; and a buffer member. The actuator is formed in a circular ring shape coaxial with the nozzle, and the liquid in each pressure chamber is pressurized by driving the actuator. The buffer member is an elastic component, which is arranged on the surface of the substrate opposite to the surface on which the nozzle plate is provided, and has a plurality of cylindrical buffer chambers with the same inner diameter as each pressure chamber, respectively arranged opposite to each pressure chamber. The common liquid chamber is connected to each pressure chamber via each buffer chamber of the buffer member. The pressure wave of the liquid generated in each pressure chamber by the drive of the actuator is absorbed by the elastic deformation of the buffer member. Therefore, the crosstalk of the pressure wave propagating to other pressure chambers can be reduced.

[0004] Citation list

[0005] Patent Literature

[0006] [PTL1] Japanese Unexamined Patent Application Publication No. 2021-41569 Summary of the Invention

[0007] Technical issues

[0008] However, in a liquid discharge head in which actuators are respectively arranged on each nozzle communication wall of a plurality of pressure chambers, although crosstalk can be reduced with the existing structure, there is a problem in that it is difficult to increase the number of nozzles per unit area.

[0009] Solutions to the Problem

[0010] In order to solve the above problems, the liquid discharge head according to the embodiment of the present disclosure includes a plurality of nozzles, a plurality of pressure chambers, a plurality of actuators, a common liquid chamber, and a buffer. The plurality of nozzles discharge liquid. The plurality of pressure chambers are respectively connected to a corresponding one of the plurality of nozzles. The plurality of actuators are respectively arranged on the nozzle connecting walls of the corresponding pressure chambers in the plurality of pressure chambers to pressurize the liquid in the corresponding pressure chambers in the plurality of pressure chambers. The common liquid chamber is connected to the plurality of pressure chambers. The buffer is arranged at a position facing the openings of the plurality of pressure chambers, and the openings face the common liquid chamber. The minimum distance between the buffer and the openings is equal to or less than the distance between the centers of two adjacent openings.

[0011] Effects of the present invention

[0012] According to one aspect of the present disclosure, in a liquid discharge head in which actuators are respectively arranged on nozzle communication walls of a plurality of pressure chambers, the number of nozzles per unit area can be increased, thereby reducing crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A more complete understanding of the embodiments of the present disclosure and many of its attendant advantages and features can be readily obtained and understood from the following detailed description taken in conjunction with the accompanying drawings.

[0014] [ Figure 1 ]

[0015] Figure 1 is a cross-sectional view schematically showing a nozzle vibration type liquid discharge head according to an embodiment of the present disclosure.

[0016] [ Figure 2 ]

[0017] Figure 2 It is schematically represented Figure 1 A perspective view of the nozzle face of a liquid discharge head.

[0018] [ Figure 3 ]

[0019] Figure 3 yes Figure 1 An enlarged cross-sectional view of a portion surrounded by a dotted line indicated by reference numeral X in FIG.

[0020] [ Figure 4 ]

[0021] Figure 4 It is schematically represented Figure 1 A plan view of the internal structure of the liquid discharge head is a sectional view taken along line CC'.

[0022] [ Figure 5 ]

[0023] Figure 5 It is schematically represented Figure 1 A front view of the internal structure of the liquid discharge head is a sectional view taken along the line AA'.

[0024] [ Figure 6 ]

[0025] Figure 6 It is schematically represented Figure 1 A side view of the internal structure of the liquid discharge head is a sectional view taken along line BB'.

[0026] [ Figure 7 ]

[0027] Figure 7 This is a graph showing simulation results of the crosstalk reduction effect of the buffer.

[0028] [ Figure 8 ]

[0029] Figure 8 This is a graph showing simulation results of the rate of change of the liquid discharge speed when the minimum distance between each opening of a plurality of pressure chambers and the buffer film is changed.

[0030] [ Figure 9 ]

[0031] Figure 9 It is a plan view schematically showing the internal structure of the liquid discharge head according to the first modification, and is a cross-sectional view taken along line CC′.

[0032] [ Figure 10 ]

[0033] Figure 10 It is schematically represented Figure 9 A side view of the internal structure of the liquid discharge head is a sectional view taken along line BB'.

[0034] [ Figure 11 ]

[0035] Figure 11 This is a plan view schematically showing the internal structure of the liquid discharge head according to the second modification, and is a cross-sectional view taken along line DD′.

[0036] [ Figure 12 ]

[0037] Figure 12 It is schematically represented Figure 11 A side view of the internal structure of the liquid discharge head is a sectional view taken along line BB'.

[0038] [ Figure 13 ]

[0039] Figure 13 This is a plan view schematically showing the internal structure of four liquid discharge heads of the head unit according to the third modification, and is a cross-sectional view taken along line CC′.

[0040] [ Figure 14 ]

[0041] Figure 14 It is schematically represented Figure 13 A side view of the internal structure of four liquid discharge heads of the head unit, which is a cross-sectional view taken along line AA'.

[0042] [ Figure 15 ]

[0043] Figure 15 This is a plan view schematically showing the internal structure of a liquid discharge head according to the fourth modification, and is a cross-sectional view taken along line CC′.

[0044] [ Figure 16 ]

[0045] Figure 16 It is schematically represented Figure 15 A front view of the internal structure of the liquid discharge head is a sectional view taken along line EE'.

[0046] [ Figure 17 ]

[0047] Figure 17 To schematically represent Figure 15 A side view of the internal structure of the liquid discharge head is a sectional view taken along line FF'.

[0048] [ Figure 18 ]

[0049] Figure 18 This is a plan view schematically showing the internal structure of four liquid discharge heads of the head unit according to Modification 5, and is a cross-sectional view taken along line CC′.

[0050] [ Figure 19 ]

[0051] Figure 19 It is schematically represented Figure 18 A side view of the internal structure of four liquid discharge heads of the head unit, which is a cross-sectional view taken along line EE'.

[0052] [ Figure 20 ]

[0053] Figure 20 This is a plan view schematically showing the internal structure of a liquid discharge head according to the sixth modification, and is a cross-sectional view taken along line CC′.

[0054] [ Figure 21 ]

[0055] Figure 21 To schematically represent Figure 20 A front view of the internal structure of the liquid discharge head is a sectional view taken along line GG'.

[0056] [ Figure 22 ]

[0057] Figure 22 To schematically represent the configuration with four Figure 20 A sectional view of the internal structure of the head unit of the liquid discharge head.

[0058] [ Figure 23 ]

[0059] Figure 23 This is a plan view schematically showing the internal structure of the liquid discharge head according to the seventh modification, and is a cross-sectional view taken along line CC′.

[0060] [ Figure 24 ]

[0061] Figure 24 It is schematically represented Figure 23 A front view of the internal structure of the liquid discharge head is a sectional view taken along the line HH'.

[0062] [ Figure 25 ]

[0063] Figure 25 To schematically represent the configuration with four Figure 23 A sectional view of the internal structure of the head unit of the liquid discharge head.

[0064] [ Figure 26 ]

[0065] Figure 26 This is a schematic explanatory diagram of a printing device according to an embodiment of the present invention.

[0066] [ Figure 27 ]

[0067] Figure 27 yes Figure 26 A plan view illustrating an example of a head unit of a printing apparatus.

[0068] [ Figure 28 ]

[0069] Figure 28 This is a plan view illustrating the main parts of a printing device according to an embodiment of the present invention.

[0070] [ Figure 29]

[0071] Figure 29 yes Figure 28 An illustrative side view of the main parts of the printing device.

[0072] [ Figure 30 ]

[0073] Figure 30 is an explanatory plan view of a main portion of a liquid discharge unit according to an embodiment of the present disclosure.

[0074] [ Figure 31 ]

[0075] Figure 31 is an explanatory front view of a liquid discharge unit according to an embodiment of the present disclosure.

[0076] The accompanying drawings are intended to illustrate embodiments of the present disclosure and should not be construed as limiting the scope thereof. Unless expressly noted otherwise, the accompanying drawings should not be considered to be drawn to scale. Furthermore, throughout the several views, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0077] When describing the embodiments shown in the accompanying drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology selected, and it should be understood that each specific component includes all technical equivalents that have similar functions, operate in a similar manner, and achieve similar results. Below, embodiments of the present invention are described with reference to the accompanying drawings. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0078] Hereinafter, a liquid discharge head according to an embodiment of the present invention included in a liquid discharge apparatus will be described.

[0079] The present invention is not limited to the embodiments described below, and may include other embodiments in addition to the embodiments described below. Within the scope apparent to those skilled in the art, the embodiments described below may be modified by, for example, addition, modification, deletion, etc. As long as the effects and features of the present invention can be exerted, these embodiments are also included in the scope of the present invention.

[0080] The liquid discharge head in this embodiment is a nozzle vibration type. An actuator mounted on a nozzle plate with a nozzle changes the pressure in a pressure chamber, discharging liquid from the nozzle. Compared to conventional unimorph piezoelectric heads (which discharge liquid by vibrating the surface of the pressure chamber facing the wall portion (nozzle communication wall) that has a communication port with the nozzle), this nozzle vibration method allows for the splashing of liquid droplets with less force, thus reducing the power consumption of the actuator.

[0081] When the nozzle density increases, the space for configuring the wiring for applying voltage is limited, making it difficult to construct the wiring on the substrate surface. By constructing the wiring and drive circuit within the substrate, the wiring can be configured even in a structure with a high nozzle density. Generally, lead zirconate titanate (PZT) is widely used as a material for the piezoelectric element of the actuator due to its high piezoelectric properties. However, when a piezoelectric film is formed on a substrate for constructing wiring and drive circuits, the film formation / crystallization temperature of the PZT film needs to be above 600°C. Therefore, when PZT is used as a material for the piezoelectric element, the drive circuit and its wiring in the substrate cannot withstand high temperatures. Therefore, in the structure in which the wiring and drive circuit are constructed within the substrate, a piezoelectric material with a lower film formation temperature than PZT is required as a piezoelectric material, and a material with lower piezoelectric properties than PZT has to be selected. However, the above-mentioned nozzle vibration type has the characteristic of being able to splash droplets with less force compared to the general single piezoelectric piece type piezoelectric head. Therefore, even if a material with lower piezoelectric properties than PZT is selected, liquid can be discharged well. Therefore, even piezoelectric materials, such as lead-free materials with low film-forming / crystallization temperatures but low power consumption, can effectively discharge liquids. This allows wiring and drive circuits to be built within the substrate, increasing density. Furthermore, since the nozzle vibration type reduces the volume of the pressure chamber, it is possible to miniaturize the liquid discharge head.

[0082] Figure 1 is a cross-sectional view schematically showing a nozzle vibration type liquid discharge head according to the present embodiment.

[0083] Figure 2 It is a perspective view schematically showing the nozzle surface of the liquid discharge head according to this embodiment.

[0084] The liquid discharge head 1 includes a nozzle plate 110, a pressure chamber substrate 100, and a common liquid chamber substrate 120. In addition, the liquid discharge head 1 also includes a buffer 130, a frame 140, and the like, which are described later.

[0085] The nozzle plate 110 has a thin film shape and includes a plurality of nozzles 2 for discharging liquid, and a piezoelectric element 5 serving as an electromechanical conversion element, which is a ring-shaped actuator arranged around the nozzles 2. The pressure chamber substrate 100 includes a plurality of pressure chambers (also referred to as individual liquid chambers and pressurized liquid chambers) 4, each of which is connected to a corresponding one of the plurality of nozzles 2. A nozzle 2 (vibrating membrane 103) is arranged on one side of each pressure chamber 4, and an opening 4a of the pressure chamber 4 and a buffer 130 are arranged on the side opposite to the one side of the pressure chamber 4. The common liquid chamber substrate 120 includes a common liquid chamber 3 that is connected to the plurality of pressure chambers 4. Electrical connection pads 55 for connecting to electrical components such as an external power supply are provided at both ends of the liquid discharge head 1.

[0086] Figure 3yes Figure 1 An enlarged cross-sectional view of a portion surrounded by a dotted line indicated by reference numeral X in FIG.

[0087] The pressure chamber substrate 100 is an SOI (Silicon On Insulator) substrate, and includes a drive circuit 101 and a wiring section 102 on the side where the diaphragm 103 is formed. The drive circuit 101 is a circuit including transistors, resistors, and the like. The wiring section 102 includes a wiring section for applying a drive waveform to the first electrode 51 and a wiring section for applying a drive waveform to the second electrode 53. Furthermore, the wiring section 102 is electrically connected to the electrical connection pad 55 via a third contact 7c opened in the diaphragm 103.

[0088] The nozzle plate 110 includes a nozzle-forming portion (membrane) 111, which is formed with multiple nozzles 2 and covers the piezoelectric element 5. A liquid-repellent film 112 is formed on the nozzle surface of the nozzle-forming portion 111. When liquid is continuously discharged, mist generated simultaneously with the discharge adheres to the nozzle surface. If a large amount of mist adheres to the nozzle surface, the liquid discharged from the nozzle 2 may be affected by the liquid adhering to the nozzle surface and deviate from the desired landing position. Forming the liquid-repellent film 112 on the nozzle surface can reduce the adhesion of liquid to the nozzle surface, thereby reducing the impact of liquid adhering to the nozzle surface on the liquid discharged from the nozzle 2.

[0089] The piezoelectric element 5 of the nozzle plate 110 includes a first electrode 51 (also referred to as a lower electrode), a piezoelectric film 52, and a second electrode 53 (also referred to as an upper electrode). The piezoelectric element 5 is covered by a first insulating film 8a. A fourth contact 7d with a hole for electrically connecting to the first electrode 51 and a fifth contact 7e with a hole for electrically connecting to the second electrode 53 are formed in the first insulating film 8a.

[0090] On the first insulating film 8a, a first lead 9a electrically connecting the first electrode 51 of the piezoelectric element 5 and the wiring portion 102 of the pressure chamber substrate 100 and a second lead 9b electrically connecting the second electrode 53 of the piezoelectric element 5 and the wiring portion 102 of the pressure chamber substrate 100 are formed.

[0091] The first lead 9a is connected to the first electrode 51 via the fourth contact 7d and to the wiring portion 102 via the first contact 7a. The second lead 9b is connected to the second electrode 53 via the fifth contact 7e and to the wiring portion 102 via the second contact 7b. The first and second leads 9a and 9b are covered by a second insulating film 8b. In this embodiment, the second insulating film 8b also covers the piezoelectric element 5, protecting the piezoelectric element 5 by preventing moisture that has entered the resin nozzle forming portion 111 from entering the piezoelectric element 5.

[0092] The lead wiring portion may be provided in each of the first electrode 51 and the second electrode 53, and the lead wiring portion may be directly connected to the wiring portion 102 in an electrode-like manner via a contact point opened on the vibration film. A close contact improving film for ensuring close contact with the nozzle forming portion 111 may be formed on the second insulating film 8b.

[0093] The liquid filling the liquid discharge head 1 enters the nozzle 2 and forms a meniscus in the nozzle. By applying a predetermined driving waveform (voltage) to the electrodes 51 and 53 of the piezoelectric element 5, the piezoelectric film 52 vibrates and the vibrating film 103 moves. Figure 3 When the diaphragm 103 vibrates, the pressure of the liquid in the pressure chamber changes, and the liquid is discharged from the nozzle 2.

[0094] In the liquid discharge head 1 of this embodiment, a protective film 11 is formed as a surface layer on the inner peripheral surface of the nozzle 2, the inner peripheral surface of the pressure chamber 4, and the bottom surface of the common liquid chamber 3. This protective film 11 has a lyophilic property for the liquid discharged by the liquid discharge head 1 and prevents erosion by the liquid. In this embodiment, the liquid discharged by the liquid discharge head 1 is alkaline, and the pressure chamber substrate 100 and the vibration membrane 103 forming the pressure chamber 4 are composed of single crystal silicon and silicon oxide. These materials are fragile to alkaline liquids and dissolve and are corroded in alkaline solutions. To prevent this, a liquid-resistant protective film 11 that prevents liquid erosion is formed, thereby protecting the pressure chamber substrate 100 and the vibration membrane 103 from the influence of the liquid.

[0095] The pressure chamber 4 and nozzle 2 are formed by dry etching. When the dry etching gas contains fluorine, a surface film containing fluorine forms on the inner wall of the pressure chamber 4 and the inner peripheral surface of the nozzle 2 after etching, making the inner wall of the pressure chamber 4 and the inner peripheral surface of the nozzle 2 liquid-repellent. If the inner peripheral surface of the pressure chamber 4 is liquid-repellent, the liquid will not wet and spread on the inner peripheral surface of the pressure chamber 4 during liquid filling. As a result, the pressure chamber 4 may not be filled with liquid properly, and bubbles may form in corners of the pressure chamber 4, etc.

[0096] In this embodiment, a lyophilic protective film 11 is formed on the inner circumferential surface of the pressure chamber 4 and the inner circumferential surface of the nozzle 2. This improves the wettability of the inner circumferential surface of the pressure chamber 4 and the nozzle 2 with the liquid. The protective film 11 only needs to be more lyophilic with respect to the liquid than the film-forming surface of the pressure chamber 4 or the nozzle 2 on which the protective film 11 is formed (the surface below the protective film 11). When the liquid solvent is aqueous, a highly hydrophilic protective film is used; when the liquid solvent is oily, a highly lipophilic protective film is used, thereby forming a highly lyophilic protective film 11.

[0097] As described above, by forming the protective film 11 on the inner circumferential surfaces of the nozzle 2 and the pressure chamber 4, which is lyophilic with respect to the liquid filling the pressure chamber 4, the liquid easily wets and spreads on the inner circumferential surfaces of the pressure chamber 4 and the nozzle 2 during liquid filling. This improves the liquid filling performance, allowing the pressure chamber 4 and the nozzle 2 to be filled with liquid smoothly without the need for pressurization or suction during liquid filling. Consequently, the occurrence of cracks in the diaphragm 103 during liquid filling can be reduced.

[0098] The liquid solvent of this embodiment is aqueous. Therefore, by forming a protective film 11 that is at least fluorine-free on the inner surface of the pressure chamber 4 and the nozzle 2, the lyophilicity can be improved compared to the fluorine-containing surface film formed by dry etching. In addition, since the film is in direct contact with various liquids, it is preferred to use a material with liquid resistance, such as a metal oxide that forms a passive state. In addition, as a method of improving lyophilicity, a substance formed by mixing a metal oxide that forms a passive state with silicon dioxide (SiO2) at a molecular level can also be used. The O on the surface of the SiO2 of the protective film 11 is replaced to form an OH group with hydrophilicity. In this way, the protective film 11 can be further given hydrophilicity. Examples of metals that can be used as metal oxides include tantalum (Ta), niobium (Nb), titanium (Ti), zirconium (Zr), hafnium (Hf), tungsten (W), etc., which have high correspondence with the oxidation number. In particular, it is particularly desirable to have Zr or Hf with a valence similar to that of SiO2, or Ta with a valence before or after it.

[0099] For example, the protective film 11 may have a double-layer structure of a liquid-resistant film and a liquid-philic film. In this case, the liquid-resistant film is formed on the inner peripheral surface of the nozzle 2 and the pressure chamber 4, and the liquid-philic film is formed on the liquid-resistant film.

[0100] In this embodiment, a lyophilic protective film 11 is also formed on the surface of the pressure chamber substrate 100 constituting the bottom surface of the common liquid chamber 3 on the side opposite to the film-forming surface of the vibration membrane 103, but the protective film 11 on this surface may only have liquid resistance. However, the process of forming the protective film 11 on the bottom surface of the common liquid chamber 3 must be set separately from the process of forming the lyophilic protective film on the inner peripheral surface of the nozzle and the wall surface of the pressure chamber, and the number of manufacturing man-hours may increase. In addition, by forming the protective film 11 on the bottom surface of the common liquid chamber 3, the liquid can easily wet and spread on the bottom surface of the common liquid chamber 3, thereby improving the filling property of the liquid. Therefore, it is preferred that a lyophilic protective film 11 is also formed on the surface of the pressure chamber substrate 100 constituting the bottom surface of the common liquid chamber 3 on the side opposite to the film-forming surface of the vibration membrane 103.

[0101] The diaphragm 103 can be made of a material that is at least insulating, such as SiO2, SiN, a metal oxide, or a resin. However, to increase displacement, a material with a low Young's modulus is ideal. Considering the difference in linear expansion coefficient from the pressure chamber substrate 100, SiO2 (silicon dioxide) is the most ideal material for the diaphragm 103.

[0102] The first electrode layer 151 and the second electrode layer 153 are preferably made of a metal with low resistance and low reactivity, preferably a metal such as Ir or Mo. The piezoelectric material of the piezoelectric layer 152 is preferably a piezoelectric material having a film formation temperature of 450°C or lower to prevent damage to the drive circuit 101 and wiring portion 102 when these are built into the pressure chamber substrate 100 to increase density, as in this embodiment. Examples of piezoelectric materials having a film formation temperature of 450°C or lower include AlN and ScAlN, which has a higher piezoelectric constant than AlN.

[0103] Furthermore, using ScAlN as the piezoelectric material offers the following advantages. Specifically, aligning the crystal orientation of the piezoelectric film 52 improves the piezoelectric characteristics. However, to control this orientation, an orientation control layer is required between the vibrating film 103 and the first electrode 51. If the piezoelectric material of the piezoelectric film 52 is ScAlN, using ScAlN as the orientation control layer also allows the lattice constant of the first electrode 51, made of Mo, to approach that of ScAlN. This results in a more consistent crystal orientation of the piezoelectric film 52, improving the piezoelectric characteristics.

[0104] Figure 4 It is a plan view schematically showing the internal structure of the liquid discharge head 1 according to the present embodiment, and is a cross-sectional view taken along line CC′.

[0105] Figure 5 It is a front view schematically showing the internal structure of the liquid discharge head 1 according to the present embodiment, and is a cross-sectional view taken along line AA′.

[0106] Figure 6 It is a side view schematically showing the internal structure of the liquid discharge head 1 according to the present embodiment, and is a cross-sectional view taken along line BB′.

[0107] like Figure 5 as well as Figure 6 As shown, the liquid discharge head 1 according to the present embodiment includes a nozzle plate 110 , a pressure chamber substrate 100 , a common liquid chamber substrate 120 , a buffer 130 , and a frame 140 in this order.

[0108] In the pressure chamber substrate 100, the area where a plurality of pressure chambers 4 are arranged is the pressure chamber array 40. The opening 4a of each pressure chamber 4 is open on the upper surface (the surface on the common liquid chamber 3 side) of the pressure chamber array 40, and the common liquid chamber 3 formed on the common liquid chamber substrate 120 is arranged to face the opening 4a of each pressure chamber 4. In this embodiment, as an example, the size of the pressure chamber 4 (the diameter of the opening 4a) is 220 micrometers (μm), and the width of the partition wall that divides the pressure chamber 4 is 30 μm. As a result, the center distance L2 between the openings 4a in two adjacent pressure chambers 4 (see Figure 6 ) is 250μm.

[0109] The buffer 130 is provided on the upper surface of the common liquid chamber substrate 120 (the surface opposite to the pressure chamber substrate 100). The common liquid chamber 3 is connected to the supply liquid storage chamber 31 formed in the frame 140 via the supply communication path 32 formed in the buffer 130. Figure 4 As shown, the supply communication path 32 of this embodiment is branched into multiple (three in the illustrated example) branches by a partition wall 130a. The partition wall 130a primarily serves as a reinforcing member, ensuring the mechanical strength of the buffer 130 and ensuring uniform liquid supply to the entire area of the common liquid chamber 3 (for uniform liquid supply to each pressure chamber 4). Therefore, as long as the mechanical strength of the buffer 130 is ensured and uniform liquid supply is possible, the partition wall 130a (reinforcement member) can be omitted, and the supply communication path 32 can be formed as a single path.

[0110] The liquid stored in the external liquid reservoir is supplied to the liquid discharge head 1 through the liquid supply port 33 of the frame 140. The liquid supplied from the liquid supply port 33 is supplied from the supply liquid storage chamber 31 to the common liquid chamber 3 through the supply communication path 32, and is supplied from the common liquid chamber 3 to each pressure chamber 4 through the opening 4a of each pressure chamber 4.

[0111] In this embodiment, if Figure 5 and Figure 6 As shown, the buffer 130 includes a buffer film 61 as a buffer member, a buffer film holding member 62 holding the buffer film 61, and an air chamber 63 for ensuring displacement or vibration of the buffer film 61. The air chamber 63 is open to the outside air through an air opening 64.

[0112] The buffer film 61 is made of a highly flexible material and is positioned across the common liquid chamber 3, facing the opening 4a of each pressure chamber 4 (in other words, on the upper surface of the pressure chamber array 40). In other words, the buffer film 61 constitutes one wall portion (the upper wall surface) of the common liquid chamber 3. With this configuration, in the damper 130, the buffer film 61 deforms in response to the crosstalk pressure of the liquid propagating into the common liquid chamber 3. This reduces pressure fluctuations caused by the crosstalk pressure generated in the common liquid chamber 3, thereby achieving the effect of reducing crosstalk (fluid crosstalk), which will be described later.

[0113] When the piezoelectric element 5 of the nozzle plate 110 vibrates the diaphragm 103, pressurizing the liquid in the pressure chamber 4, the pressure becomes a force for discharging the liquid from the nozzle 2. However, a portion of this pressure escapes from the opening 4a of the pressure chamber 4 into the common liquid chamber 3 and becomes a crosstalk pressure. The crosstalk pressure that has escaped into the common liquid chamber 3 propagates through the liquid in the common liquid chamber 3 and flows to the other surrounding pressure chambers 4, causing pressure fluctuations in the liquid in the other pressure chambers 4, thereby affecting the discharge of the liquid in the other pressure chambers 4 from the nozzle 2.

[0114] Here, in this embodiment, since the common liquid chamber 3 is interposed between the buffer film 61 and the opening 4a of each pressure chamber 4, the buffer film 61 needs to be arranged away from the opening 4a of each pressure chamber 4 to ensure the flow of liquid in the common liquid chamber 3. In other words, the distance between each opening 4a of the plurality of pressure chambers 4 and the buffer film 61, that is, the distance L1 between the top surface of the pressure chamber array 40 and the buffer film 61 (see Figure 6 ) is set to a size sufficient to ensure the flow of liquid in the common liquid chamber 3.

[0115] At this time, if the distance L1 between the top surface of the pressure chamber array 40 and the buffer membrane 61 is excessively increased to ensure a sufficiently wide shared liquid chamber 3, the crosstalk pressure absorbed by the buffer membrane 61 decreases, and the crosstalk reduction effect is reduced. As a result, crosstalk may occur. In particular, in this embodiment, since the so-called nozzle vibration type is adopted, a liquid discharge head with a large number of nozzles (the number of pressure chambers) per unit area can be provided. However, in this liquid discharge head, the distance between the pressure chambers 4 is short, and therefore, crosstalk may occur.

[0116] Therefore, in this embodiment, the minimum distance L1 between each opening 4a of the multiple pressure chambers 4 and the buffer membrane 61 is equal to or less than the center-to-center distance L2 between the openings 4a of two adjacent pressure chambers 4. With this configuration, the majority of the pressure wave (crosstalk pressure) from the opening 4a of each pressure chamber 4 reaches the buffer membrane 61 before passing through the liquid in the common liquid chamber 3 and reaching the opening 4a of the adjacent pressure chamber 4. As a result, the effect of the pressure wave (crosstalk pressure) reaching the opening 4a of another pressure chamber 4 from each pressure chamber 4 on the pressure fluctuations in the liquid in that other pressure chamber 4 can be minimized, achieving a sufficient crosstalk reduction effect.

[0117] However, if the minimum distance L1 between each opening 4a of the multiple pressure chambers 4 and the buffer film 61 is too small, the fluid resistance (viscous resistance, etc.) of the liquid flowing through the common liquid chamber 3 becomes too high, and this may lead to insufficient liquid supply to each pressure chamber 4. This problem becomes particularly significant when using high-viscosity liquids or when liquid is discharged at a high frequency. Furthermore, if the minimum distance L1 is too small, when the liquid is sucked out from the nozzle 2 side by a suction device for the purpose of cleaning the nozzle 2, the common liquid chamber 3 becomes too narrow due to deformation of the buffer film 61. As a result, the flow of liquid is hindered, and a sufficient cleaning effect cannot be achieved, or the buffer film 61 may come into contact with the pressure chamber substrate 100 and be damaged.

[0118] In consideration of such a problem, the minimum distance L1 between each opening portion 4 a of the plurality of pressure chambers 4 in the liquid and the buffer film 61 in the present embodiment is preferably 10 μm or more, more preferably 50 μm or more.

[0119] Buffer film 61 is preferably made of a material with low rigidity (high flexibility), durability, and absorbency for the liquid to be discharged. Specifically, preferred materials for buffer film 61 include resin films such as polyimide (PI) and polyphenylene sulfide (PPS), and metal films such as stainless steel and nickel. However, if buffer film 61 is too thin, pinholes may occur. Therefore, the thickness of buffer film 61 is preferably within a range of approximately 1 μm or greater and 50 μm or less.

[0120] When a resin film is used as the buffer film 61, it is preferably provided with a moisture-proof film. This is to prevent components of the liquid in the common liquid chamber 3 from entering the air chamber 63 through the buffer film 61 and leaking into the outside air through the atmosphere opening 64. The moisture-proof film can be provided by forming a film of metal or metal oxide on the resin film by sputtering or the like.

[0121] Figure 7 This is a graph showing simulation results of the crosstalk reduction effect of the buffer 130 according to the present embodiment.

[0122] In this graph, the rate of change in the liquid discharge speed when the number of nozzles driven simultaneously (the number of adjacent nozzles) is changed is simulated for an example in which the buffer 130 is not provided (buffer-free example) and an example in which the buffer 130 is provided (buffer-equipped example). The rate of change in the liquid discharge speed is the rate of change when the liquid discharge speed during liquid discharge using only one nozzle is 100%.

[0123] In this simulation, the buffer film 61 made of a stainless steel film having a thickness of 10 μm is used as the buffer 130 , and the minimum distance L1 between the upper face of the pressure chamber array 40 and the buffer film 61 is set to 100 μm.

[0124] from Figure 7 As can be seen from the graph, without a buffer, for example, as the number of simultaneously driven nozzles increases, the liquid discharge speed at 40 nozzles changes by more than 50% relative to the liquid discharge speed at 1 nozzle. On the other hand, with a buffer, even at 40 nozzles, for example, the rate of change in the liquid discharge speed relative to 1 nozzle is less than 5%. Providing the buffer 130 in this manner achieves a crosstalk reduction effect.

[0125] Figure 8 4 is a graph showing simulation results of the rate of change of the liquid discharge speed when the minimum distance L1 between each opening 4 a of the plurality of pressure chambers 4 and the buffer film 61 is changed.

[0126] In this simulation, the number of nozzles driven simultaneously is 10. The change rate of the liquid discharge speed in this simulation is the change rate when the liquid discharge speed is 100% when the minimum distance L1 between each opening 4a of the plurality of pressure chambers 4 and the buffer film 61 is 100 μm.

[0127] from Figure 8 As can be seen from the graph, when the minimum distance L1 between each opening 4a of the plurality of pressure chambers 4 and the buffer film 61 is 250 μm or less, the rate of change in the liquid discharge rate decreases to less than 5% (within the allowable range). On the other hand, when the minimum distance L1 is 500 μm, the rate of change in the liquid discharge rate is 20%.

[0128] Here, Figure 7 The graph of the case where the number of nozzles driven simultaneously is 10 (the case where the minimum distance L1 is 100 μm) is the same as Figure 8 The comparison is made with the case where the minimum distance L1 in the graph of FIG is 500 μm (the case where the number of nozzles driven simultaneously is 10). According to this comparison, although the buffer 130 is provided, when Figure 8The change rate of the liquid discharge speed when the minimum distance L1 in the graph is 500 μm is the same as when the buffer 130 is not provided (at Figure 7 The rate of change of the liquid discharge speed is basically the same as that of the case where no buffer is provided. In other words, Figure 8 When the minimum distance L1 in the graph is 500 μm, it can be seen that the crosstalk reduction effect of the buffer 130 is not obtained.

[0129] On the other hand, according to Figure 8 The curve graph shows that when the minimum distance L1 between each opening 4a of the plurality of pressure chambers 4 and the buffer film 61 is less than 250 μm, the change rate is substantially the same as when the minimum distance L1 is 100 μm (the change rate of the liquid discharge speed is less than 5%). Figure 7 Similarly to the case where there is a buffer in the graph (the minimum distance L1 is 100 μm), even if the number of simultaneously driven nozzles increases, the change in the liquid discharge speed is reduced, thereby exerting a sufficient crosstalk reduction effect.

[0130] The distance of 250 μm corresponds to the center-to-center distance L2 between the openings 4a in two adjacent pressure chambers 4. This is believed to be the result of the fact that, by satisfying L1 ≤ L2, the majority of the crosstalk pressure (pressure wave) escaping from the opening 4a of each pressure chamber 4 to the common liquid chamber 3 during liquid discharge reaches and is absorbed by the buffer membrane 61 before passing through the liquid within the common liquid chamber 3 and reaching the opening 4a of the other adjacent pressure chamber 4. In other words, if L1 > L2, the component of the crosstalk pressure (pressure wave) that is not absorbed by the buffer membrane 61 and reaches the opening 4a of the other adjacent pressure chamber 4 increases, and the impact on the pressure fluctuations of the liquid in the other pressure chamber 4 cannot be ignored, and a sufficient crosstalk reduction effect cannot be achieved.

[0131] As described above, according to this embodiment, since the minimum distance L1 between each opening portion 4a of the plurality of pressure chambers 4 and the buffer film 61 is equal to or less than the center-to-center distance L2 between the opening portions 4a of two adjacent pressure chambers 4, a sufficient crosstalk reduction effect can be obtained.

[0132] First Modification

[0133] Next, a modification of the liquid discharge head 1 according to the present embodiment will be described (hereinafter, this modification is referred to as “first modification”).

[0134] The liquid discharge head 1 of the first modified example is different from the liquid discharge head 1 of the above-described embodiment in that the position of the supply communication path 32 formed in the buffer 130 is changed.

[0135] Figure 9It is a plan view schematically showing the internal structure of the liquid discharge head 1 according to the first modification, and is a cross-sectional view taken along line CC′.

[0136] Figure 10 It is a side view schematically showing the internal structure of the liquid discharge head 1 according to the first modification, and is a cross-sectional view taken along line BB′.

[0137] In the liquid discharge head 1 of the above embodiment, in the area ( Figure 4 A supply communication path 32 is formed in the area (shown as an area outside the long side 40a of the pressure chamber array 40) that connects the common liquid chamber 3 of the common liquid chamber substrate 120 with the supply liquid storage chamber 31 of the frame 140. In other words, in the liquid discharge head 1 of the above-described embodiment, the supply communication path 32 for supplying liquid to the common liquid chamber 3 connects to the common liquid chamber 3 outside the pressure chamber array 40 in the short side direction of the pressure chamber array 40 including the plurality of pressure chambers 4.

[0138] On the other hand, in the liquid discharge head 1 of the first modified example, the supply communication path 32 is formed outside the pressure chamber array 40 in the longitudinal direction (outside the short side 40b of the pressure chamber array 40). In other words, in the liquid discharge head 1 of the first modified example, the supply communication path 32 for supplying liquid to the common liquid chamber 3 communicates with the common liquid chamber 3 outside the pressure chamber array 40 including the plurality of pressure chambers 4 in the longitudinal direction.

[0139] According to the first modified example, since the supply communication path 32 is formed outside the pressure chamber array 40 in the longitudinal direction (outside the short side 40b of the pressure chamber array 40), there is no need to provide space for forming the supply communication path 32 in the area outside the pressure chamber array 40 in the short side direction. Consequently, the liquid discharge head can be miniaturized in the short side direction of the pressure chamber array 40. In particular, when using a head unit in which multiple liquid discharge heads are arranged in the short side direction of the pressure chamber array 40, miniaturization of the liquid discharge heads in the short side direction of the pressure chamber array 40 provides a significant advantage in miniaturization of the head unit.

[0140] However, in this embodiment and the first modified example, since the minimum distance L1 between each opening 4a of the plurality of pressure chambers 4 and the buffer film 61 is reduced to fully achieve the crosstalk reduction effect, the fluid resistance (viscous resistance, etc.) of the liquid within the common liquid chamber 3 tends to increase. Consequently, when the distance the liquid flows within the common liquid chamber 3 is long (e.g., exceeding several mm), the fluid resistance becomes excessively high, leading to insufficient liquid supply in pressure chambers 4 that are distant from the supply communication path 32. This can potentially make stable liquid discharge difficult. This problem is particularly pronounced when the ink viscosity is high or the drive frequency is high.

[0141] In the first modified embodiment, since the supply communication path 32 is formed outside the pressure chamber array 40 in the longitudinal direction, the distance that liquid flows from the supply communication path 32 in the common liquid chamber 3 to the pressure chambers 4 farther away from the supply communication path 32 is longer than in the case of the aforementioned embodiment, in which the supply communication path 32 is formed in the outer region of the pressure chamber array 40 in the short-side direction of the pressure chamber array 40. Therefore, this embodiment is more advantageous in addressing the aforementioned issues. In particular, the greater the ratio of the long side 40a to the short side 40b of the pressure chamber array 40, the more advantageous this embodiment becomes.

[0142] Of course, depending on conditions such as when the viscosity of the liquid used is low or when the driving frequency is low, the above-mentioned problem does not occur even with the structure of the first modified example, and the structure of the first modified example can be adopted.

[0143] Second Modification

[0144] Next, another modification of the liquid discharge head 1 according to the present embodiment will be described (hereinafter, this modification is referred to as “second modification”).

[0145] The liquid discharge head 1 of the second modified example is different from the liquid discharge head 1 of the above-described embodiment in that a fluid resistance portion 4 b is provided at the opening 4 a of each pressure chamber 4 .

[0146] Figure 11 The diagram is a plan view schematically showing the internal structure of the liquid discharge head 1 according to the second modification, and is a cross-sectional view taken along the line DD′.

[0147] Figure 12 It is a side view schematically showing the internal structure of the liquid discharge head 1 according to the second modification, and is a cross-sectional view taken along line BB′.

[0148] In the second modified example, a fluid resistance substrate 150 is inserted between the pressure chamber substrate 100 and the common liquid chamber substrate 120. Figure 11 and Figure 12As shown, a fluid resistance portion 4b is provided on the fluid resistance substrate 150. The opening area of the opening 4a of the fluid resistance portion 4b (the opening area parallel to the nozzle surface) is smaller than the cross-sectional area (the area of the cross section parallel to the nozzle surface) of the pressure chamber 4. The provision of the fluid resistance portion 4b can increase the fluid resistance of the liquid moving from each pressure chamber 4 to the common liquid chamber 3.

[0149] The fluid resistance substrate 150 can have multiple openings narrower than the cross-sectional area of the pressure chamber 4 (the area of the cross section parallel to the nozzle surface) at positions corresponding to the pressure chamber 4. The fluid resistance substrate 150 can be made of, for example, metal, silicon, ceramic, or resin. The fluid resistance portion 4b (the opening formed in the fluid resistance substrate 150) can be formed by wet etching, dry etching, electroforming, cutting, laser processing, or the like.

[0150] By providing such a fluid resistance portion 4 b , the crosstalk pressure generated in each pressure chamber 4 can be limited to each pressure chamber 4 as much as possible, and the crosstalk pressure leaking from each pressure chamber 4 through the opening 4 a to the common liquid chamber 3 can be reduced.

[0151] According to the second modified example, a liquid discharge head 1 having a higher crosstalk reduction effect can be provided compared to the above-described embodiment in which the fluid resistance portion 4b is not provided. In particular, according to the second modified example, the provision of the fluid resistance portion 4b increases the margin of the crosstalk suppression effect. Therefore, L1 can be increased as much as possible within the condition of L1 ≤ L2, thereby reducing the fluid resistance of the liquid flowing through the common liquid chamber 3. In other words, according to the second modified example, even when attempting to obtain the same degree of crosstalk reduction effect as the liquid discharge head 1 of the above-described embodiment, the fluid resistance of the liquid flowing through the common liquid chamber 3 can be reduced by increasing L1, making it less likely that the problem of unstable discharge performance caused by insufficient liquid supply to the pressure chamber 4 will occur.

[0152] Third Modification

[0153] Next, still another modification of the liquid discharge head 1 according to the present embodiment will be described (hereinafter, this modification is referred to as “third modification”).

[0154] The third modification is an example of a head unit 10 in which a plurality of liquid discharge heads 1 are arranged in a row in the short-side direction of the pressure chamber array 40. The liquid discharge heads 1 of the head unit 10 are the same as those of the above-described embodiment.

[0155] Figure 13 This is a plan view schematically showing the internal structure of the four liquid discharge heads 1 of the head unit 10 according to the third modification, and is a cross-sectional view taken along the line CC′.

[0156] Figure 141 is a side view schematically showing the internal structure of four liquid discharge heads 1 of a head unit 10 according to a third modification, and is a cross-sectional view taken along line AA′.

[0157] The head unit 10 of the third modified example has an integrated structure in which four liquid ejection heads 1 of the above-described embodiment are arranged in the short-side direction of the pressure chamber array 40. This head unit 10 can be used, for example, as a recording head (inkjet head) for an image forming device (liquid ejection device) that forms images using four different inks: yellow (Y), magenta (M), cyan (C), and black (K). By integrating the four liquid ejection heads 1 as in the third modified example, a compact recording head can be obtained, reducing the number of assembly steps required for the recording head and the image forming device.

[0158] Fourth Modification

[0159] Next, another modified example of the liquid discharge head 1 according to the present embodiment (hereinafter, this modified example is referred to as a “fourth modified example”) will be described.

[0160] The liquid discharge head 1 of the fourth variant is different from the liquid discharge head 1 of the above embodiment in that it has a supply flow path (supply liquid storage chamber 31, supply communication path 32, liquid supply port 33, etc.) for supplying liquid to the common liquid chamber 3 and a transport flow path for transporting liquid from the common liquid chamber 3.

[0161] Figure 15 This is a plan view schematically showing the internal structure of the liquid discharge head 1 according to the fourth modification, and is a cross-sectional view taken along the line CC′.

[0162] Figure 16 1 is a front view schematically showing the internal structure of the liquid discharge head 1 according to the fourth modification, and is a cross-sectional view taken along line EE′.

[0163] Figure 17 This is a side view schematically showing the internal structure of a liquid discharge head according to a fourth modification, and is a cross-sectional view taken along line FF′.

[0164] Likewise, in the fourth modification, liquid supplied from the external ink reservoir via the liquid supply port 33 of the frame 140 is supplied to the common liquid chamber 3 via the supply liquid storage chamber 31 and the supply communication path 32. However, in the fourth modification, the common liquid chamber 3 communicates with the transfer liquid storage chamber 35 formed in the frame 140 via the transfer communication path 34 formed in the buffer 130. As a result, the liquid in the common liquid chamber 3 flows from the transfer communication path 34 through the transfer liquid storage chamber 35, and is returned to the external ink reservoir from the liquid delivery port 36 via an external pump or the like. In other words, the fourth modification is a liquid discharge head 1 having a liquid circulation system.

[0165] According to the fourth modification, the liquid in the common liquid chamber 3 can be circulated. As a result, bubbles existing in the flow path (such as the common liquid chamber 3) within the liquid discharge head 1 can be removed, or when using a liquid having a component that may precipitate, the precipitation of the liquid component in the flow path (such as the common liquid chamber 3) within the liquid discharge head 1 can be reduced.

[0166] In particular, in the fourth modified example, the supply communication path 32 and the delivery communication path 34 are each formed in an area outside the pressure chamber array 40 in the short-side direction of the pressure chamber array 40 (an area outside the long side 40a of the pressure chamber array 40). Therefore, the distance that liquid flows in the common liquid chamber 3 facing the pressure chamber array 40 (the longest distance when the liquid flows from the supply communication path 32 to the delivery communication path 34) is minimized. Therefore, in the fourth modified example, since the minimum distance L1 between each opening 4a of the plurality of pressure chambers 4 and the buffer membrane 61 is small, the fluid resistance (such as viscous resistance) of the liquid in the common liquid chamber 3 is high. However, by minimizing the distance that the liquid flows in the common liquid chamber 3, the fluid resistance of the liquid in the common liquid chamber 3 can be suppressed to a low level.

[0167] Fifth Modification

[0168] Next, another modified example of the liquid discharge head 1 according to the present embodiment (hereinafter, this modified example is referred to as a “fifth modified example”) will be described.

[0169] The fifth modification is an example of a head unit 10 in which a plurality of the liquid ejecting heads 1 of the fourth modification are arranged in parallel in the short-side direction of the pressure chamber array 40 .

[0170] Figure 18 This is a plan view schematically showing the internal structure of the four liquid discharge heads 1 of the head unit 10 according to the fifth modification, and is a cross-sectional view taken along the line CC′.

[0171] Figure 19 1 is a side view schematically showing the internal structure of four liquid discharge heads 1 of a head unit 10 according to a fifth modification, and is a cross-sectional view taken along line EE′.

[0172] The head unit 10 of the fifth modification has a structure in which four liquid ejection heads 1 (liquid circulation type liquid ejection heads) of the fourth modification are arranged in the short-side direction of the pressure chamber array 40, forming an integrated structure. Similar to the head unit 10 of the third modification, the head unit 10 can be used, for example, as a recording head (inkjet head) for an image forming device (liquid ejection device) that forms images using four different inks: yellow (Y), magenta (M), cyan (C), and black (K). By integrating the four liquid ejection heads 1 as in the fifth modification, a compact recording head can be obtained, reducing the number of assembly steps required for the recording head and image forming device.

[0173] Sixth Modification

[0174] Next, another modified example of the liquid discharge head 1 according to the present embodiment (hereinafter, this modified example is referred to as a “sixth modified example”) will be described.

[0175] The liquid discharge head 1 of the sixth modification differs from the liquid discharge head 1 of the aforementioned embodiment in that, similar to the fourth modification, the liquid circulation system includes a supply flow path (such as a supply liquid storage chamber 31, a supply communication path 32, and a liquid supply port 33) for supplying liquid to the common liquid chamber 3, and a delivery flow path for delivering liquid from the common liquid chamber 3. However, the liquid discharge head 1 of the sixth modification differs from the liquid discharge head 1 of the fourth modification in that the position of the delivery communication path 34 formed in the buffer 130 is changed.

[0176] Figure 20 The diagram is a plan view schematically showing the internal structure of the liquid discharge head 1 according to the sixth modification, and is a cross-sectional view taken along the line CC′.

[0177] Figure 21 This is a front view schematically showing the internal structure of the liquid discharge head 1 according to the sixth modification, and is a cross-sectional view taken along the line GG′.

[0178] In the liquid discharge head 1 of the fourth modified example, both the supply communication path 32 and the delivery communication path 34 are formed in the area outside the pressure chamber array 40 in the short-side direction of the pressure chamber array 40 (the area outside the long side 40a of the pressure chamber array 40). Therefore, it is necessary to provide space for forming both the supply communication path 32 and the delivery communication path 34 outside the short-side direction of the pressure chamber array 40, thereby facilitating the enlargement of the liquid discharge head in the short-side direction of the pressure chamber array 40. In particular, as Figure 18 as well as Figure 19When the plurality of liquid discharge heads 1 are arranged in the short-side direction of the pressure chamber array 40 as in the head unit 10 of the fifth modified example shown, the head unit 10 is greatly enlarged in the short-side direction of the pressure chamber array 40 .

[0179] Furthermore, because spaces for forming both the supply communication path 32 and the delivery communication path 34 are provided outside the pressure chamber array 40 in the short-side direction, the pressure chamber substrate 100 is enlarged in the short-side direction of the pressure chamber array 40. This increases the area of the pressure chamber substrate 100. For pressure chamber substrates 100 manufactured using MEMS (Micro Electro Mechanical Systems) technology, an increase in substrate area directly leads to an increase in cost.

[0180] On the other hand, in the liquid discharge head 1 of the sixth modified example, the supply communication path 32 is formed in an area outside the pressure chamber array 40 in the short-side direction of the pressure chamber array 40, and the delivery communication path 34 is formed outside the pressure chamber array 40 in the long-side direction (outside the short side 40b of the pressure chamber array 40). As a result, since the space for forming the delivery communication path 34 can be omitted outside the short-side direction of the pressure chamber array 40, the liquid discharge head can be miniaturized in the short-side direction of the pressure chamber array 40 compared to the liquid discharge head 1 of the fourth modified example. This miniaturization effect is achieved as follows: Figure 22 This is particularly effective when a plurality of liquid ejecting heads 1 according to the sixth modification are arranged side by side in the short-side direction of the pressure chamber array 40 as in the head unit 10 shown.

[0181] Furthermore, in the liquid discharge head 1 of the sixth modification, by forming the transport communication path 34 outside the pressure chamber array 40 in the longitudinal direction, the substrate area on which the transport communication path 34 must be formed can be reduced compared to the liquid discharge head 1 of the fourth modification, in which the transport communication path 34 is formed in a region outside the pressure chamber array 40 in the width direction. Therefore, compared to the liquid discharge head 1 of the fourth modification, the substrate area of the pressure chamber substrate 100 can be reduced, thereby suppressing cost increases.

[0182] In the sixth modified example, because the transport communication path 34 is formed outside the pressure chamber array 40 in the longitudinal direction, the distance that liquid flows within the common liquid chamber 3 (the maximum distance liquid flows from the supply communication path 32 to the transport communication path 34) facing the pressure chamber array 40 is longer than in the fourth modified example, in which both the supply communication path 32 and the transport communication path 34 are formed outside the pressure chamber array 40 in the width direction. Consequently, when discharging liquid while circulating the liquid within the common liquid chamber 3, insufficient liquid supply to the pressure chamber 4 may result, making stable liquid discharge difficult. This problem is particularly pronounced in applications with high ink viscosity or high drive frequencies.

[0183] In the event of such a malfunction, liquid may be transferred from the common liquid chamber 3 using the transfer flow path (e.g., the transfer communication path 34, the transfer liquid storage chamber 35, the liquid transfer port 36) only during the initial liquid filling of the liquid discharge head 1 or during maintenance of the liquid discharge head 1, even if bubbles are transferred. In this case, since the liquid in the common liquid chamber 3 does not circulate during the liquid discharge operation, the pressure chamber 4 is less likely to be insufficiently supplied with liquid, and stable liquid discharge becomes relatively easy.

[0184] In the sixth modification, a structure in which the supply flow path and the delivery flow path are interchanged can also be adopted. In other words, the supply communication path 32 can be formed outside the pressure chamber array 40 in the longitudinal direction, and the delivery communication path 34 can be formed outside the pressure chamber array 40 in the width direction.

[0185] Seventh Modification

[0186] Next, another modified example of the liquid discharge head 1 according to the present embodiment (hereinafter, this modified example is referred to as a “seventh modified example”) will be described.

[0187] The liquid discharge head 1 of the seventh modification differs from the liquid discharge head 1 of the above-described embodiment in that, similar to the fourth and sixth modifications, the liquid circulation system includes a supply flow path (e.g., a supply liquid storage chamber 31, a supply communication path 32, and a liquid supply port 33) for supplying liquid to the common liquid chamber 3, and a delivery flow path (e.g., a delivery communication path 34, a delivery liquid storage chamber 35, and a liquid delivery port 36) for delivering liquid from the common liquid chamber 3. However, in the liquid discharge head 1 of the seventh modification, the positions of the supply communication path 32 and the delivery communication path 34 formed in the buffer 130 differ from those of the liquid discharge heads 1 of the fourth and sixth modifications.

[0188] Figure 23The diagram is a plan view schematically showing the internal structure of the liquid discharge head 1 according to the seventh modification, and is a cross-sectional view taken along the line CC′.

[0189] Figure 24 It is a front view schematically showing the internal structure of the liquid discharge head 1 according to the seventh modification, and is a cross-sectional view taken along line HH′.

[0190] In the liquid discharge head 1 of the seventh modified example, the supply communication path 32 and the delivery communication path 34 are both formed outside the pressure chamber array 40 in the longitudinal direction (outside the short side 40b of the pressure chamber array 40). As a result, since the space for forming the supply communication path 32 and the space for forming the delivery communication path 34 can be omitted outside the pressure chamber array 40 in the width direction, the liquid discharge head can be miniaturized in the width direction of the pressure chamber array 40 compared to the liquid discharge heads 1 of the fourth and sixth modified examples. This miniaturization effect is achieved in the following aspects: Figure 25 This is particularly effective when a plurality of liquid ejecting heads 1 according to the seventh modification are arranged in parallel in the width direction of the pressure chamber array 40 , as in the head unit 10 shown.

[0191] In the liquid discharge head 1 of the seventh modification, since both the supply channel 32 and the transport channel 34 are formed on the outside of the pressure chamber array 40 in the longitudinal direction, the substrate area of the pressure chamber substrate 100 can be further reduced compared to the liquid discharge head 1 of the fourth modification, thereby further suppressing cost increases. The liquid discharge head 1 of the seventh modification also has the advantage of easily simplifying the structures of the supply channel and the transport channel.

[0192] In the liquid discharge head 1 of the seventh modified example, because both the supply communication path 32 and the delivery communication path 34 are formed longitudinally outside the pressure chamber array 40, the distance that liquid flows within the common liquid chamber 3 (the maximum distance liquid flows from the supply communication path 32 to the delivery communication path 34) facing the pressure chamber array 40 is longer than that of the liquid discharge head 1 of the fourth modified example. Consequently, insufficient liquid supply to the pressure chamber 4 may lead to difficulty in stable liquid discharge. This problem is particularly significant when the ink viscosity is high or the driving frequency is high.

[0193] However, in the seventh modified example of the liquid discharge head 1, since both the supply communication path 32 and the delivery communication path 34 are formed on the outside of the pressure chamber array 40 in the longitudinal direction, the substrate area of the pressure chamber substrate 100 can be reduced, further suppressing cost increases. Depending on conditions such as the low viscosity of the liquid being used or the low drive frequency, the structure of the seventh modified example may be employed without causing the aforementioned problems. Alternatively, the delivery communication path 34 may serve as a second supply communication path, allowing liquid to be supplied from both the supply communication path 32 and the delivery communication path 34.

[0194] Next, we will refer to Figure 26 and Figure 27 A liquid discharge device according to an embodiment of the present disclosure is described.

[0195] Figure 26 It is a schematic explanatory diagram of a printing apparatus as an inkjet recording apparatus which is an image forming apparatus as a liquid discharge apparatus of this embodiment.

[0196] Figure 27 This is a plan view illustrating an example of a head unit of the printing apparatus according to the present embodiment.

[0197] The printing device 500, which is a device for discharging liquid, includes a loading unit 501 for loading a continuous body 510, and a guide and conveying unit 503 for guiding and conveying the continuous body 510 loaded from the loading unit 501 to a printing mechanism 505. Furthermore, the printing device 500 includes a printing mechanism 505 for printing an image by discharging liquid onto the continuous body 510, a drying mechanism 507 for drying the continuous body 510, and a discharge unit 509 for discharging the continuous body 510.

[0198] The continuous body 510 is fed from the take-in unit 501 by the take-up roller 511 and guided and conveyed by the rollers of the take-in unit 501, the guide conveying unit 503, the drying mechanism 507, and the take-out unit 509, before being wound around the take-up roller 591 of the take-out unit 509. In the printing mechanism 505, the continuous body 510 is conveyed on the conveyance guide member 559 in a direction opposite to the head unit 550. The head unit 550 discharges liquid to form an image on the continuous body 510.

[0199] In the printing apparatus 500 of the present embodiment, the head unit 550 includes the two head modules 100A and 100B according to the present embodiment described above on a common base member 552 .

[0200] When the arrangement direction of the liquid discharge heads 1 in the liquid discharge head modules 100A and 100B, which is perpendicular to the transport direction, is defined as the head arrangement direction, the head arrays 1A1 and 1A2 of the liquid discharge head module 100A discharge liquid of the same color. Similarly, the head arrays 1B1 and 1B2 of the liquid discharge head module 100A discharge liquid of the same desired color as a group. The head arrays 1C1 and 1C2 of the liquid discharge head module 100B discharge liquid of the same desired color as a group. The head arrays 1D1 and 1D2 of the liquid discharge head module 100B discharge liquid of the same desired color as a group.

[0201] Next, refer to Figure 28 as well as Figure 29 , a printing device as a liquid ejection device according to another embodiment of the present invention will be described.

[0202] Figure 28 is an explanatory plan view of a main portion of the printing apparatus according to the present embodiment.

[0203] Figure 29 is an explanatory side view of a main portion of the printing apparatus according to the present embodiment.

[0204] The printing device 500 of this example is a serial-type device, in which the carriage 403 is reciprocated in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is mounted between a left plate 491A and a right plate 491B to movably hold the carriage 403. The main scanning motor 405 reciprocates the carriage 403 in the main scanning direction via a timing belt 408 mounted between a drive pulley 406 and a driven pulley 407.

[0205] According to an embodiment of the present disclosure, the liquid discharge head 1 and the head tank 441 are provided as a single body integrated in the liquid discharge unit 440, which is mounted on the carriage 403. The liquid discharge head 1 ejects liquids of various colors, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid discharge head 1 has a nozzle array consisting of a plurality of nozzles arranged in a sub-scanning direction orthogonal to the main scanning direction. The liquid discharge head 1 is installed so that ink droplets are discharged downward. The liquid discharge head 1 is connected to a liquid circulation device that circulates and supplies liquid of a desired color.

[0206] The printing device 500 includes a conveyor 495 for conveying a sheet 410. The conveyor 495 includes a conveyor belt 412 as a conveying means and a sub-scanning motor 416 that drives the conveyor belt 412. The conveyor belt 412 attracts the sheet 410 and conveys it to a position facing the liquid discharge head 1. The conveyor belt 412 is an endless belt stretched between a conveyor roller 413 and a tension roller 414. The attraction can be applied by electrostatic adsorption, air suction, etc. When the conveyor roller 413 is rotationally driven by the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418, the conveyor belt 412 rotates in the sub-scanning direction.

[0207] A maintenance and recovery mechanism 420 for maintaining the liquid discharge head 1 in good condition is provided on one side of the carriage 403 in the main scanning direction, to the side of the conveyor belt 412. The maintenance and recovery mechanism 420 includes, for example, a cap member 421 for capping the nozzle surface of the liquid discharge head 1, a wiper member 422 for wiping the nozzle surface, and the like. The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the conveyor 495 are mounted on a housing including side plates 491A and 491B and a back plate 491C.

[0208] In the printing apparatus 500 configured as described above, the sheet 410 is fed and attracted onto the conveyor belt 412, and the sheet 410 is conveyed in the sub-scanning direction by the circumferential movement of the conveyor belt 412. While the carriage 403 moves in the main scanning direction, the liquid discharge head 1 is driven in response to an image signal to discharge liquid onto the stopped sheet 410, thereby forming an image on the sheet 410.

[0209] Next, we will refer to Figure 30 A liquid discharge unit according to another embodiment of the present disclosure is described.

[0210] Figure 30 is an explanatory plan view of a main portion of the liquid discharge unit according to the present embodiment.

[0211] The liquid discharge unit 440 is composed of a housing including side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493 , a carriage 403 , and a liquid discharge head 1 , among components constituting a device for discharging the liquid.

[0212] In the liquid discharge unit 440 , for example, the above-mentioned maintenance recovery mechanism 420 may also be mounted on the side plate 491B.

[0213] Next, we will refer to Figure 31 A liquid discharge unit according to still another embodiment of the present disclosure is described.

[0214] Figure 31 It is a front explanatory diagram of the liquid discharge unit according to this embodiment.

[0215] The liquid discharge unit 440 includes the liquid discharge head 1 to which a flow path member 444 is mounted, and a tube 456 connected to the flow path member 444 .

[0216] The flow path member 444 is provided in the cover 442. The liquid discharge unit 440 may include a head tank 441 instead of the flow path member 444. A connector 443 electrically connected to the liquid discharge head 1 is provided on the upper portion of the flow path member 444.

[0217] In this embodiment, the discharged liquid is not particularly limited, as long as the liquid has a viscosity or surface tension discharged from the head (liquid discharge head). However, it is preferred that the viscosity of the liquid is not more than 30 mPa·s at room temperature and pressure or by heating or cooling. As liquids, for example, functional materials such as solvents such as water and organic solvents, pigments such as dyes and pigments, polymerizable compounds, resins, surfactants, DNA (deoxyribonucleic acid), biocompatible materials such as amino acids, proteins, calcium, and edible materials such as natural pigments can be cited. These can be used, for example, for inkjet inks, surface treatment liquids, liquids for forming anti-etching patterns of components of electronic components or light-emitting components or electronic circuits, and material solutions for three-dimensional manufacturing.

[0218] A "liquid discharge unit" is a collection of components related to liquid discharge, integrating functional components or mechanisms with a liquid discharge head. For example, a "liquid discharge unit" includes a combination of a liquid discharge head and at least one of a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0219] Examples of integration include a combination in which the liquid discharge head and one or more functional components or mechanisms are fixed to each other by, for example, fastening, bonding, or joining, and a combination in which one of the liquid discharge head and the functional component or mechanism is movably held by the other. The liquid discharge head may be detachably attached to the functional component or mechanism.

[0220] For example, the liquid discharge head and the head tank may be formed as an integrated liquid discharge unit. Alternatively, the liquid discharge head and the head tank may be connected by a tube or the like and formed as an integrated liquid discharge unit. A unit including a filter may be added between the head tank and the liquid discharge head of the liquid discharge unit.

[0221] In another example, the liquid discharge head and the carriage may be formed as an integrated liquid discharge unit.

[0222] The liquid discharge unit includes a liquid discharge head movably held by a guide member forming part of a main scanning movement mechanism so that the liquid discharge head and the main scanning movement mechanism are integrated. The liquid discharge unit may include the integrated liquid discharge head, the carriage, and the main scanning movement mechanism.

[0223] A cover forming a portion of the maintenance recovery mechanism may be fixed to a carriage on which the liquid discharge head is mounted, so that the liquid discharge head, the carriage, and the maintenance recovery mechanism are integrated to form a liquid discharge unit.

[0224] The liquid discharge unit includes a pipe connected to a liquid discharge head mounted with a flow path member or a head tank so that the liquid discharge head and the supply mechanism are integrated. The liquid in the liquid storage source is supplied to the liquid discharge head through the pipe.

[0225] The main scanning movement mechanism may be only a guide member. The supply mechanism may be only a tube or only a filling portion.

[0226] Here, the “liquid discharge unit” is described as being combined with a liquid discharge head. However, the “liquid discharge unit” also includes a head module or head unit including the liquid discharge head integrated with the functional components and mechanisms described above.

[0227] The term "liquid discharge device" also includes devices that are equipped with a liquid discharge head, a liquid discharge unit, a head module, a head unit, etc., and that drive the liquid discharge head to discharge liquid. A liquid discharge device may not only discharge liquid onto a material to which the liquid can adhere, but also discharge liquid into a gas or a liquid.

[0228] The liquid discharge device may include a pre-processing device, a post-processing device, and the like in addition to units related to paper feeding, conveying, and paper discharge to which liquid may adhere.

[0229] The “liquid discharge device” is, for example, an image forming device that forms an image on a sheet by ejecting ink, or a three-dimensional molding device that forms a three-dimensional object by ejecting molding liquid onto a powder layer of stacked powder material.

[0230] The "liquid discharge device" is not limited to a device that discharges liquid to visualize a meaningful image such as letters or graphics. For example, the liquid discharge device also includes a device for forming a pattern that itself has no meaning, or a device for producing a three-dimensional image.

[0231] The term "liquid-adhesive material" as used above refers to a material to which liquid can at least temporarily adhere, a material to which liquid adheres and solidifies, or a material to which liquid adheres and permeates. Specific examples of "liquid-adhesive materials" include, but are not limited to, recording media such as paper, recording paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers, organ models, and inspection units. Unless otherwise specified, these terms encompass all objects to which liquid can adhere.

[0232] Examples of the material of the above-mentioned "liquid-adhesive object" include any material to which liquid can adhere even temporarily, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc.

[0233] A "liquid discharge device" includes, but is not limited to, a device in which a liquid discharge head and an object to which liquid can adhere move relative to each other. Specific examples include a serial type device in which the liquid discharge head moves, and a linear type device in which the liquid discharge head does not move.

[0234] In addition to these, "liquid discharge devices" include liquid coating devices that coat the surface of paper with a treatment liquid for the purpose of modifying the surface of the paper and discharge the treatment liquid onto the paper, and jet granulation devices that granulate the raw material particles by spraying a combination liquid obtained by dispersing the raw material in a solution through a nozzle.

[0235] The terms image formation, recording, printing, image printing, and shaping used in this application may be used as synonyms.

[0236] The above-mentioned embodiments are merely limited examples, and the present disclosure includes, for example, the following aspects having advantageous effects.

[0237] First aspect

[0238] A liquid discharge head (e.g., liquid discharge head 1) includes: a plurality of nozzles (e.g., nozzles 2) that discharge liquid; a plurality of pressure chambers (e.g., pressure chambers 4) each communicating with a corresponding one of the plurality of nozzles; a plurality of actuators (e.g., piezoelectric elements 5) disposed on nozzle communication walls (e.g., nozzle plate 110) of corresponding ones of the plurality of pressure chambers, pressurizing the liquid within the corresponding ones of the plurality of pressure chambers; a common liquid chamber (e.g., common liquid chamber 3) communicating with the plurality of pressure chambers; and a buffer (e.g., buffer film 61) disposed at a position facing openings of the plurality of pressure chambers, the openings facing the common liquid chamber. A minimum distance (e.g., minimum distance L1) between the buffer and each opening is equal to or less than a center-to-center distance (e.g., center-to-center distance L2) between two adjacent openings.

[0239] In conventional liquid ejection heads, where the buffer is located on the wall forming the flow path from the common liquid chamber to each pressure chamber, sufficient space for the buffer is required. This makes it difficult to shorten the distance between adjacent pressure chambers. Consequently, the distance between nozzles cannot be shortened, and the number of nozzles per unit area cannot be increased.

[0240] In this aspect, the common liquid chamber is arranged so as to oppose and communicate with the openings of the plurality of pressure chambers, and the buffer is arranged so as to oppose the openings of the plurality of pressure chambers via the common liquid chamber. This eliminates the need for the buffer to be arranged as a wall portion forming a flow path from the common liquid chamber to the pressure chambers. Therefore, compared to the above-described structure, the distance between adjacent pressure chambers can be shortened, the distance between nozzles can be shortened, and the number of nozzles per unit area can be increased.

[0241] However, in this structure, depending on the setting of the height of the common liquid chamber between the buffer and the openings of the multiple pressure chambers (the distance between the buffer and the openings of the multiple pressure chambers), crosstalk has been confirmed to occur, and the pressure waves of the liquid generated in each pressure chamber by the actuator drive are propagated to other pressure chambers.

[0242] Therefore, in this aspect, the minimum distance between each opening of the multiple pressure chambers and the buffer is equal to or less than the center-to-center distance between the openings of two adjacent pressure chambers. This structure allows the majority of the pressure waves from the opening of each pressure chamber to reach the buffer before passing through the liquid in the shared liquid chamber and reaching the opening of the adjacent pressure chamber. As a result, the impact of pressure waves from each pressure chamber reaching the openings of other pressure chambers on pressure fluctuations in the liquid within those other pressure chambers can be minimized, thereby reducing crosstalk.

[0243] Second aspect

[0244] In the above-described first aspect, the minimum distance (eg, the minimum distance L1 ) is 250 μm or less.

[0245] This increases the number of nozzles per unit area and reduces crosstalk.

[0246] The third aspect

[0247] In the above-described first or second aspect, the minimum distance (eg, the minimum distance L1 ) is 10 μm or greater.

[0248] This makes it easier to ensure the flow of liquid in the common liquid chamber, reduce the occurrence of pressure chambers with insufficient liquid supply, and achieve stable liquid discharge.

[0249] The fourth aspect

[0250] In any one of the first to third aspects, it further includes a supply flow path (for example, a supply liquid storage chamber 31, a supply communication path 32 and a liquid supply port 33) for supplying liquid to the common liquid chamber, and the supply flow path is connected to the common liquid chamber on the outside in the width direction of the pressure chamber array (for example, the pressure chamber array 40) including the multiple pressure chambers.

[0251] Therefore, even if the fluid resistance of the liquid in the common liquid chamber (e.g., common liquid chamber 3) increases by reducing the minimum distance between the opening of each pressure chamber and the buffer (e.g., minimum distance L1), the increase in fluid resistance of the liquid in the common liquid chamber (e.g., common liquid chamber 3) can be reduced by reducing the distance that the liquid supplied from the supply flow path flows through the common liquid chamber to each pressure chamber. Therefore, the occurrence of insufficient liquid supply to the pressure chamber can be reduced, and stable liquid discharge can be achieved.

[0252] The fifth aspect

[0253] In any one of the first to third aspects, further comprising: a supply flow path (e.g., a supply liquid storage chamber 31, a supply communication path 32, and a liquid supply port 33) for supplying liquid to the common liquid chamber; and a delivery flow path (e.g., a delivery communication path 34, a delivery liquid storage chamber 35, a liquid delivery port 36) for delivering liquid from the common liquid chamber.

[0254] Therefore, since the liquid in the common liquid chamber can be circulated, bubbles present in the flow path within the liquid discharge head such as the common liquid chamber can be removed, or when a liquid with components that easily settle is used, the sedimentation of liquid components in the flow path within the liquid discharge head such as the common liquid chamber can be reduced.

[0255] The sixth aspect

[0256] In the fifth aspect, the supply flow path is connected to the common liquid chamber outside the width direction of the pressure chamber array (for example, the pressure chamber array 40) including the multiple pressure chambers, and the transport flow path is connected to the common liquid chamber outside the length direction of the pressure chamber array.

[0257] Therefore, compared to a configuration in which both the supply and transfer channels connect to the common liquid chamber outside the width of the pressure chamber array, a smaller width can be achieved. Compared to a configuration in which both the supply and transfer channels connect to the common liquid chamber outside the length of the pressure chamber array, the distance liquid flows within the common liquid chamber is longer, increasing the fluid resistance of the liquid within the common liquid chamber (e.g., common liquid chamber 3), which can sometimes make circulation within the common liquid chamber difficult. However, the transfer channel can serve as a liquid discharge path during initial filling or maintenance, facilitating the discharge of bubbles and making stable liquid discharge relatively easy.

[0258] Seventh aspect

[0259] In the fifth aspect, the supply flow path communicates with the common liquid chamber outside the pressure chamber array including the plurality of pressure chambers in the width direction, and the transport flow path communicates with the common liquid chamber outside the pressure chamber array in the width direction.

[0260] Therefore, compared to a configuration in which the supply channel communicates with the common liquid chamber outside the width direction of the pressure chamber array and the transport channel communicates with the common liquid chamber outside the length direction of the pressure chamber array, the distance that the liquid discharged from the common liquid chamber flows to the transport channel is shortened, the fluid resistance of the liquid in the common liquid chamber (e.g., common liquid chamber 3) is reduced, and the occurrence of insufficient liquid supply to the pressure chamber is reduced, stable liquid discharge can be achieved, and the liquid in the common liquid chamber (e.g., common liquid chamber 3) can be circulated. As a result, bubbles existing in the flow path such as the common liquid chamber (e.g., common liquid chamber 3) in the liquid discharge head (e.g., liquid discharge head 1) can be removed. In the case of using a liquid having a component that may settle, the sedimentation of the liquid component in the flow path such as the common liquid chamber (e.g., common liquid chamber 3) in the liquid discharge head (e.g., liquid discharge head 1) can be reduced.

[0261] The eighth aspect

[0262] In any one of the first to seventh aspects, a fluid resistance portion (for example, the fluid resistance portion 4 b ) is arranged in the opening.

[0263] Therefore, the fluid resistance portion can seal the crosstalk pressure generated in each pressure chamber in each pressure chamber as much as possible, and can reduce the crosstalk pressure leaking from each pressure chamber through the opening portion to the common liquid chamber. In particular, according to this aspect, by providing the fluid resistance portion, the redundancy of the crosstalk reduction effect is increased, so the minimum distance (for example, the minimum distance L1) between the opening portion (for example, the opening portion 4a) and the buffer can be made as large as possible to reduce the fluid resistance of the liquid flowing through the common liquid chamber. In other words, according to this aspect, even in the case of wanting to obtain the same degree of crosstalk suppression effect as a liquid discharge head without such a fluid resistance portion, by further increasing the minimum distance (for example, the minimum distance L1) between the opening portion (for example, the opening portion 4a) and the buffer, the fluid resistance of the liquid flowing through the common liquid chamber can be reduced, and the problem of unstable discharge performance due to insufficient liquid supply to the pressure chamber is unlikely to occur.

[0264] Ninth aspect

[0265] A liquid discharge apparatus includes the liquid discharge head according to any one of the first to eighth aspects.

[0266] This makes it possible to provide a liquid discharge device that increases the number of nozzles per unit area and reduces crosstalk.

[0267] The above embodiments are illustrative and do not limit the present invention. Therefore, based on the above teachings, many additional modifications and variations are possible. For example, within the scope of the present invention, the elements and / or features of the different illustrative embodiments can be combined with each other and / or replaced with each other.

[0268] This patent application is based upon and claims the benefit of priority from Japanese patent application No. 2023-003283 filed with the Japan Patent Office on January 12, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0269] Reference Signs List

[0270] 1 Liquid discharge head

[0271] 2 nozzles

[0272] 3 Common liquid chamber

[0273] 4 Pressure chamber

[0274] 4a Opening

[0275] 4b Fluid resistance part

[0276] 5 Piezoelectric elements

[0277] 10 head units

[0278] 31 Supply liquid storage chamber

[0279] 32 Supply communication path

[0280] 33 Liquid supply port

[0281] 34 Transport communication path

[0282] 35 Transfer liquid storage chamber

[0283] 36 Liquid delivery port

[0284] 40 pressure chamber arrays

[0285] 40a Long side

[0286] 40b short side

[0287] 51 first electrode

[0288] 52 piezoelectric film

[0289] 53 second electrode

[0290] 61 Buffer Film

[0291] 62 Buffer film retaining member

[0292] 63 Air Chamber

[0293] 64 atmospheric openings

[0294] 100 Pressure chamber substrate

[0295] 101 drive circuit

[0296] 102 Wiring Department

[0297] 103 Vibrating Membrane

[0298] 110 nozzle plate

[0299] 111 Nozzle forming portion

[0300] 112 liquid-proof film

[0301] 120 Common liquid chamber substrate

[0302] 130 Buffer

[0303] 130a Partition wall

[0304] 140 Frame

Claims

1. A liquid discharge head comprising: a plurality of nozzles that discharge liquid; A plurality of pressure chambers, each of which is connected to a corresponding one of the plurality of nozzles; a plurality of actuators, respectively disposed on the nozzle communicating walls of corresponding pressure chambers in the plurality of pressure chambers, for pressurizing the liquid in the corresponding pressure chambers in the plurality of pressure chambers; a common liquid chamber communicating with the plurality of pressure chambers; and a buffer provided at a position facing the openings of the plurality of pressure chambers, the openings facing the common liquid chamber, The minimum distance between the buffer and each of the openings is equal to or smaller than a distance between centers of two adjacent openings.

2. The liquid discharge head according to claim 1, in, The minimum distance is 250 microns or less.

3. The liquid discharge head according to claim 1 or 2, in, The minimum distance is 10 micrometers or greater.

4. The liquid discharge head according to any one of claims 1 to 3, further comprising a supply flow path for supplying liquid to the common liquid chamber, in, The supply flow path communicates with the common liquid chamber on the outside in the width direction of the pressure chamber array including the plurality of pressure chambers.

5. The liquid discharge head according to any one of claims 1 to 3, further comprising: a supply flow path that supplies liquid to the common liquid chamber; and The delivery channel is used to deliver the liquid from the common liquid chamber.

6. The liquid discharge head according to claim 5, in, The supply flow path communicates with the common liquid chamber outside the pressure chamber array including the plurality of pressure chambers in the width direction, and The transfer flow path communicates with the common liquid chamber on the outside in the longitudinal direction of the pressure chamber array.

7. The liquid discharge head according to claim 5, in, The supply flow path communicates with the common liquid chamber outside the pressure chamber array including the plurality of pressure chambers in the width direction, and The transfer flow path communicates with the common liquid chamber on the outside of the pressure chamber array in the width direction.

8. The liquid discharge head according to any one of claims 1 to 7, in, A fluid resistance portion is disposed in the opening. 9 . A liquid discharge device comprising the liquid discharge head according to claim 1 .

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