Liquid discharge head and recording device

Abstract

To reduce a possibility of affecting a discharge characteristic.MEANS FOR SOLVING THE PROBLEM: A liquid discharge head 1 includes: a plurality of discharge members 2 having a nozzle 21, a pressure chamber 31 connected with the nozzle 21 and an individual flow path 50 connected with the pressure chamber 31; and a common flow path member having a common flow path 300 for supplying liquid commonly with the plurality of discharge members 2. The individual flow path 50 includes an opening 51 connected with the common flow path 300. A space between the opening 51 and an upper surface 330 of the common flow path 300 is configured by a space A in which the liquid is to be located.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection head and a recording apparatus. [Background technology]

[0002] Patent Document 1 discloses a liquid ejection head that includes a nozzle, a pressure chamber connected to the nozzle, a piezoelectric element provided above the pressure chamber, individual flow paths connected to the pressure chamber, and a common flow path connected to the openings of the individual flow paths. In such a liquid ejection head, liquid flows from the common flow path into the pressure chamber through the openings of the individual flow paths. Displacement of the piezoelectric element generates a pressure wave in the pressure chamber, which ejects liquid from the nozzle. A portion of the pressure wave generated in the pressure chamber is propagated to the common flow path via the individual flow paths. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-151707 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional liquid ejection head described above, a flow path member is located between the openings of the individual flow paths and the upper surface of the common flow path, and there is a possibility that pressure waves propagated to the common flow path are reflected from the openings of the individual flow paths by the side surface of the flow path member. The pressure waves reflected by the side surface of the flow path member may propagate to other pressure chambers, affecting the ejection characteristics of the liquid ejection head.

[0005] An object of the present invention is to reduce the possibility of affecting the ejection characteristics of a liquid ejection head. [Means for solving the problem]

[0006] A liquid ejection head according to one aspect of the present disclosure comprises a nozzle, a pressure chamber connected to the nozzle, a plurality of ejection members each having an individual flow path connected to the pressure chamber, and a common flow path member having a common flow path that supplies liquid to the plurality of ejection members in common, wherein the individual flow paths include openings that connect to the common flow path, and a space for positioning liquid is formed between the openings and the upper surface of the common flow path. [Effects of the Invention]

[0007] According to one aspect of the present disclosure, it is possible to reduce the possibility of affecting the ejection characteristics of the liquid ejection head. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view schematically showing a printer according to a first embodiment. [Figure 2] FIG. 1 is a plan view schematically showing a printer according to a first embodiment. [Figure 3] FIG. 1 is a plan view schematically showing a liquid ejection head according to a first embodiment. [Figure 4] 4 is a view of the liquid ejection head shown in FIG. 3 as viewed from A. FIG. [Figure 5] 4 is a view of the liquid ejection head shown in FIG. 3 as viewed from B. FIG. [Figure 6] FIG. 2 is a plan view schematically showing the discharge member according to the first embodiment. [Figure 7] 7 is a view of the discharge member shown in FIG. 6 as seen from C. FIG. [Figure 8] FIG. 7 is a cross-sectional view taken along line II shown in FIG. [Figure 9] FIG. 7 is a cross-sectional view taken along line II-II shown in FIG. [Figure 10] 1A is a plan view showing a common flow path member and each of the components constituting the common flow path member; (a) is a plan view showing the common flow path member; (b) is a plan view showing only the first common flow path member; and (c) is a plan view showing only the second common flow path member. [Figure 11] FIG. 10(b) is a cross-sectional view taken along line III-III shown in FIG. [Figure 12] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. [Figure 13] FIG. 13 is a cross-sectional view of an area V shown in FIG. [Figure 14] 1 is a cross-sectional view showing an example of the configuration of a liquid ejection head according to a first embodiment. [Figure 15] FIG. 2 is a plan view showing a common flow path member in the first embodiment. [Figure 16] FIG. 16 is a cross-sectional view taken along line VV shown in FIG. [Figure 17] FIG. 10 is a cross-sectional view of a liquid ejection head according to a second embodiment. [Figure 18] FIG. 10 is a cross-sectional view of a liquid ejection head according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] Please note that the drawings used in the following explanation are schematic, and the dimensional ratios in the drawings do not necessarily correspond to the actual ones. Even among multiple drawings showing the same configuration, the dimensional ratios may not correspond to each other because the shapes and the like are exaggerated.

[0011] (First embodiment) The configuration of a printer 100 according to this embodiment will be described with reference to FIGS.

[0012] FIG. 1 is a side view that schematically shows a printer 100 according to this embodiment. FIG. 2 is a plan view that schematically shows the printer 100. The printer 100 is, for example, a color inkjet printer. For ease of understanding, FIG. 1 illustrates a three-dimensional Cartesian coordinate system that includes an X-axis with the positive direction toward the right of the page and a Y-axis with the positive direction toward the back of the page. This Cartesian coordinate system is also shown in other drawings that will be used in the following description.

[0013] In the following description, for convenience, the positive Z-axis direction may be referred to as "upper." The X-axis direction is the transport direction of the printing paper P. In addition, "planar view" refers to a view from the Z-axis direction.

[0014] As shown in FIG. 1, the printer 100 includes a paper feed roller 101, a guide roller 102, a transport roller 103, a recovery roller 104, a liquid ejection head 1, a fixing plate 105, a dryer 106, a sensor unit 107, and a control unit .

[0015] The control unit 108 controls the operations of the paper feed roller 101, guide roller 102, transport roller 103, recovery roller 104, dryer 106, and sensor unit 107. The control unit 108 also has a transmission unit 109. The transmission unit 109 transmits signals to the liquid ejection heads 1, so that the control unit 108 controls the driving of the liquid ejection heads 1. The signals are transmitted from the transmission unit 109 to each liquid ejection head 1 via a connection unit 110 such as a cable or a flexible substrate.

[0016] The paper feed roller 101, guide roller 102, transport roller 103, and recovery roller 104 constitute a moving unit that moves the print paper P and the liquid ejection head 1 relative to one another. The print paper P is an example of a recording medium. The moving unit is controlled by a control unit 108. The print paper P passes from the paper feed roller 101 between two guide rollers 102A and is transported onto multiple transport rollers 103. The print paper P then passes between two guide rollers 102B and two guide rollers 102C and is transported to the recovery roller 104.

[0017] The fixed plate 105 is flat and is positioned close to the top of the printing paper P being transported by the transport rollers 103. They are located adjacent to each other.

[0018] Each liquid ejection head 1 has an elongated shape that is elongated in the Y-axis direction. Four liquid ejection heads 1 are mounted on a fixed plate 105. The four liquid ejection heads 1 are lined up on the fixed plate 105 along the X-axis direction of the printing paper P. The fixed plate 105 also has through-holes that allow each liquid ejection head 1 to be inserted. Therefore, the liquid ejection heads 1 are fixed to the fixed plate 105 by being inserted into the through-holes. Each liquid ejection head 1 is supplied with the same color liquid and ejects the liquid toward the printing paper P. The four liquid ejection heads 1 can print four colors of liquid. The colors of the liquid ejected from each liquid ejection head 1 are, for example, magenta, yellow, cyan, and black. The printer 100 can print color images by impacting such liquid onto the printing paper P. The type of liquid color can be changed as appropriate.

[0019] The liquid ejection head 1 according to this embodiment is fixed to the printer 100, which is a so-called line printer. Note that the printer 100 is not limited to a line printer, but may be a so-called serial printer in which the liquid ejection head 1 is moved in a direction intersecting the Y-axis direction of the printing paper P to eject liquid and the printing paper P to transport alternately.

[0020] The liquid ejection head 1 is controlled by the control unit 108 based on data such as images or characters, and ejects liquid toward the printing paper P. The distance between the liquid ejection head 1 and the printing paper P is, for example, 0.5 to 20 mm.

[0021] Furthermore, in addition to printing colored liquids, a liquid such as a coating agent may be printed uniformly or in a pattern using the liquid ejection head 1 to treat the surface of the printing paper P. Note that instead of using the liquid ejection head 1, a coating agent may be applied using an applicator (not shown).

[0022] The dryer 106 dries the printing paper P. After passing through the two guide rollers 102B, the printing paper P is dried by the dryer 106. By drying in the dryer 106, the overlapping printing paper P wound up on the collection roller 104 is less likely to stick to each other, and the undried liquid is less likely to rub against each other.

[0023] The sensor unit 107 includes a position sensor, a speed sensor, a temperature sensor, etc. The control unit 108 can control each part of the printer 100 based on information from each sensor.

[0024] The printer 100 may be provided with a cleaning unit that cleans the liquid ejection head 1. The cleaning unit cleans the ejection surface of the liquid ejection head 1 by, for example, wiping or capping.

[0025] The recording medium may be a roll of cloth in addition to printing paper P. The printer 100 may also transport the recording medium on a transport belt. In this case, sheets of paper, cut pieces of cloth, wood, tiles, or the like can be used as the recording medium. Furthermore, a liquid containing conductive particles may be ejected from the liquid ejection head 1 to print wiring patterns for electronic devices. Furthermore, a chemical agent may be produced by ejecting a predetermined amount of liquid chemical agent or a liquid containing a chemical agent from the liquid ejection head 1 toward a reaction vessel or the like, and causing a reaction.

[0026] The configuration of the liquid ejection head 1 according to this embodiment will be described with reference to FIGS. 3, 4, and 5. Fig. 3 is a plan view schematically showing the liquid ejection head 1 according to this embodiment. Fig. 4 is a side view of the liquid ejection head 1 shown in Fig. 3 as seen from A. Fig. 5 is a side view of the liquid ejection head 1 shown in Fig. 3 as seen from B.

[0027] The liquid ejection head 1 includes an ejection member 2, a common flow path member 3, a protective member 4, a flexible substrate 5, a driving IC 6, a wiring substrate 7, an input IC 8, a heat sink 9, and a nozzle cover 10.

[0028] Each ejection member 2 has a plate-like shape elongated in the Y-axis direction. The ejection members 2 are capable of ejecting liquid and directly contribute to printing. Each liquid ejection head 1 includes eight ejection members 2. The four ejection members 2 on the negative X-axis side are positioned along the Y-axis direction within the liquid ejection head 1. The four ejection members 2 on the positive X-axis side are positioned along the Y-axis direction within the liquid ejection head 1, aligned between the four ejection members 2 on the negative X-axis side. In other words, the multiple ejection members 2 are positioned in a staggered pattern within the liquid ejection head 1. The ejection members 2 are also arranged so that they partially overlap in the X-axis direction within the liquid ejection head 1. The number of ejection members 2 included in one liquid ejection head 1 can be adjusted appropriately depending on the printing target or printing conditions. The constituent materials of the ejection members 2, excluding the wiring, piezoelectric element, and diaphragm, are silicon.

[0029] The common flow path member 3 is positioned above the plurality of discharge members 2. The common flow path member 3 has a common flow path that supplies liquid to the plurality of discharge members 2. The common flow path member 3 also includes a plurality of first common flow path members 301 and a second common flow path member 302.

[0030] The first common flow path member 301 has a plate-like shape elongated in the Y-axis direction. Each of the multiple first common flow path members 301 is positioned above a corresponding one of the multiple discharge members 2. That is, in this embodiment, one liquid discharge head 1 has eight first common flow path members 301. Each of the multiple first common flow path members 301 supplies liquid to a corresponding one of the multiple discharge members 2. The material of the first common flow path member 301 is preferably metal or resin. The material of the first common flow path member 301 according to this embodiment is preferably metal having a thermal expansion coefficient close to that of silicon. When the first common flow path member 301 is made of metal, it is possible to reduce the possibility of distortion occurring in the first common flow path member 301 and the discharge member 2 due to a large difference in thermal expansion coefficients when, for example, the first common flow path member 301 and the discharge member 2 are thermally bonded.

[0031] The second common flow path member 302 has an elongated shape extending from the end on the positive Y-axis direction side to the end on the negative Y-axis direction side within the liquid ejection head 1. The second common flow path member 302 is positioned above the plurality of first common flow path members 301. The second common flow path member 302 supplies liquid to the plurality of first common flow path members 301. The material of the second common flow path member 302 according to this embodiment is made of resin. Because resin has low heat resistance, it is preferable to join or adhere the second common flow path member 302 and the first common flow path member 301 without heating.

[0032] The protective member 4 covers the top and side surfaces of the second common flow path member 302. In other words, when viewed from the Y-axis direction, the protective member 4 has a U-shape with a closed top surface. Here, "covering" does not necessarily mean completely covering the entire surface; for example, it is sufficient to cover only a portion of the surface. Because the protective member 4 covers the top and side surfaces of the second common flow path member 302, it is possible to reduce the effects of external impacts on the second common flow path member 302. The protective member 4 is made of, for example, metal. Therefore, the protective member 4 has high rigidity, and is therefore able to further reduce the effects of external impacts on the second common flow path member 302.

[0033] The protection member 4 according to this embodiment is joined to the upper surface of the second common flow path member 302. The second common flow path member 302 has an elongated shape in the Y-axis direction, and thus warping in the Y-axis direction is likely to occur. The protective member 4 is joined to the upper surface of the second common flow path member 302, thereby reducing warping of the second common flow path member 302. The protective member 4 only needs to be joined to at least one of the upper surface and side surface of the second common flow path member 302. The protective member 4 according to this embodiment is joined to the upper surface of the second common flow path member 302 using a plurality of screws, thereby further reducing warping of the second common flow path member 302.

[0034] One flexible substrate 5 according to this embodiment is bonded to each of the plurality of discharge members 2. That is, the number of flexible substrates 5 according to this embodiment is eight. One end of the flexible substrate 5 is electrically connected to the discharge member 2, and the other end of the flexible substrate 5 is drawn out above the second common flow path member 302.

[0035] One driving IC 6 according to this embodiment is mounted on each of the multiple flexible substrates 5. That is, the number of driving ICs 6 according to this embodiment is eight. The driving ICs 6 are electrically connected to the flexible substrates 5.

[0036] The wiring board 7 has an elongated shape in the Y-axis direction. The wiring board 7 is positioned on the second common flow path member 302. The side surfaces of the wiring board 7 on the positive X-axis side and the negative X-axis side have larger areas than the side surfaces on the positive Y-axis side and the negative Y-axis side. By arranging the side surfaces of the wiring board 7 with the larger areas along the Y-axis and Z-axis directions, the possibility of the liquid ejection head 1 becoming large in the X-axis direction can be reduced. In other words, the liquid ejection head 1 according to this embodiment can be reduced in size in the transport direction, which is more restrictive. Furthermore, the side surface of the wiring board 7 on the positive X-axis side is electrically connected to the four flexible substrates 5 on the positive X-axis side. Furthermore, the side surface of the wiring board 7 on the negative X-axis side is electrically connected to the four flexible substrates 5 on the negative X-axis side. In other words, the wiring board 7 is sandwiched between multiple flexible substrates 5 in a plan view.

[0037] The input IC 8 is located on the wiring board 7. The input IC 8 is electrically connected to the wiring board 7. The input IC 8 receives a plurality of signals transmitted from the transmitter 109 via the connection unit 110. The plurality of signals transmitted from the transmitter 109 are transmitted as serial signals. In this embodiment, the signals are transmitted from the transmitter 109 to the input IC 8 using, for example, the V-by-One (registered trademark) transmission method. The input IC 8 performs serial-to-parallel conversion and generates a plurality of parallel signals from the transmitted serial signals. The input IC 8 acquires the plurality of parallel signals and extracts data signals to be transmitted to each driver IC 6.

[0038] The driving ICs 6 are electrically connected to the input ICs 8 via the wiring board 7 and the flexible substrate 5. Data signals are transmitted from the input ICs 8 to the driving ICs 6 via the wiring board 7 and the flexible substrate 5. Each driving IC 6 generates a driving signal based on the data signal.

[0039] The discharge member 2 is electrically connected to a driving IC 6 via a flexible substrate 5. A drive signal is transmitted to the discharge member 2 from the driving IC 6 via the flexible substrate 5. The discharge member 2 discharges liquid based on the drive signal.

[0040] The heat sinks 9 are located at the end of the liquid ejection head 1 on the positive side of the X axis and the end on the negative side of the X axis. The heat sink 9 located on the positive side of the X axis is in contact with the four flexible substrates 5 located on the positive side of the X axis. The heat sink 9 located on the negative side of the X axis is in contact with the four flexible substrates 5 located on the negative side of the X axis. The heat sink 9 is made of a material with high thermal conductivity, such as silicone or polyolefin. The liquid ejection head 1 according to this embodiment is Since the heat sink 9 is in contact with the flexible substrate 5, the possibility that the driving IC 8 generates heat and the heat is transferred to the discharge member 2 via the flexible substrate 5 can be reduced.

[0041] Furthermore, since the flexible substrate 5 is in contact with the protective member 4 made of metal on the side opposite to the side in contact with the heat sink 9, the liquid ejection head 1 of this embodiment can further reduce the possibility that the driving IC 8 will generate heat and that heat will be conducted to the ejection member 2 via the flexible substrate 5.

[0042] The nozzle cover 10 constitutes a portion located below the liquid ejection head 1. The nozzle cover 10 has a plate-like shape elongated in the Y-axis direction. The nozzle cover 10 has through-holes in the Z-axis direction at the portions where the ejection members 2 are located so that the ejection members 2 can be ejected. Positioning the lower surface of the nozzle cover 10 lower than the lower surfaces of the ejection members 2 reduces the possibility of the print medium coming into contact with the ejection surfaces of the ejection members 2 during printing. The nozzle cover 10 is also bent toward the positive direction of the Z-axis at its end on the positive X-axis side and its end on the negative X-axis side. The X-axis direction is the direction of relative movement between the print medium and the liquid ejection head 1 during printing. Therefore, in the liquid ejection head 1 according to this embodiment, the nozzle cover 10 has bent portions toward the positive X-axis side and the negative X-axis side relative to the multiple ejection members 2, thereby reducing the possibility of the multiple ejection members 2 coming into contact with the print medium from the positive X-axis side and the negative X-axis side. The nozzle cover 10 is made of a highly rigid metal to protect the ejection members 2 from the print medium. The nozzle cover 10 and each discharge member 2 are bonded together with an adhesive.

[0043] The configuration of the discharge member 2 according to this embodiment will be described with reference to Figures 6, 7, 8, and 9. Figure 6 is a plan view that schematically shows the discharge member 2 according to this embodiment. Figure 7 is a side view of the discharge member 2 shown in Figure 6, as seen from the C side. Figure 8 is a cross-sectional view taken along line II in Figure 6. Figure 9 is a cross-sectional view taken along line II in Figure 6. Note that the two wavy lines drawn in the vertical direction of the paper in Figure 6 represent omission lines.

[0044] The discharge member 2 comprises a nozzle member 20, an actuator member 30, and a support member .

[0045] The nozzle member 20 includes a plurality of nozzles 21. The plurality of nozzles 21 are through-holes that penetrate the nozzle member 20 in the Z-axis direction. The plurality of nozzles 21 are positioned along the Y-axis direction to form nozzle groups. The discharge member 2 according to this embodiment has two nozzle groups: a nozzle group on the positive X-axis direction side and a nozzle group on the negative X-axis direction side. The discharge member 2 according to this embodiment has two nozzle groups, but may have only one nozzle group or three or more nozzle groups. The two nozzle groups according to this embodiment are configured parallel to each other. The distance between the nozzles 21 in each nozzle group is 84.6 μm. In other words, the resolution of the nozzles 21 in the nozzle groups is 300 dpi. The nozzles 21 in the nozzle group on the positive X-axis direction side are respectively positioned between the nozzles 21 in the nozzle group on the negative X-axis direction side in the Y-axis direction. In other words, the nozzles 21 in the nozzle group on the positive side of the X axis and the nozzles 21 in the nozzle group on the negative side of the X axis are shifted from each other in the Y axis direction, and the resolution of the nozzles 21 in the two nozzle groups combined is 600 dpi. Note that the spacing between the nozzles 21 in each nozzle group may be set appropriately depending on the resolution.

[0046] The actuator member 30 includes a single crystal silicon substrate 33, a vibration plate 34, and a plurality of piezoelectric elements 35. The single crystal silicon substrate 33 is located on the nozzle member 20. The vibration plate 34 is located on the silicon substrate 33. The plurality of piezoelectric elements 35 are located on the vibration plate 34. A plurality of pressure chambers 31 and a plurality of first apertures 32 are formed in the single crystal silicon substrate 33. When viewed from above, the actuator member 30 according to this embodiment has a nozzle It has almost the same shape as the casing member 20.

[0047] The multiple pressure chambers 31 are through-holes that penetrate the single-crystal silicon substrate 33 in the Z-axis direction and are respectively connected to the multiple nozzles 21. According to this embodiment, the multiple pressure chambers 31 are physically connected to the multiple nozzles 21, but this is not limiting. For example, the multiple pressure chambers 31 may be fluidly connected to the multiple nozzles 21 via channels such as descenders. In other words, the concept of "connected" is not limited to being physically connected, but also includes being fluidly connected. The multiple pressure chambers 31 are located along the Y-axis direction. Furthermore, when viewed in a plan view, the multiple pressure chambers 31 are located such that their longitudinal direction is aligned with the X-axis direction and their lateral direction is aligned with the Y-axis direction. According to this embodiment, the pressure chambers 31 have a substantially rectangular planar shape, but this is not limiting. For example, the pressure chambers 31 may have a diamond or circular planar shape. Liquid is stored in the pressure chambers 31. When pressure is applied to the liquid in the pressure chambers 31, the liquid is ejected from the nozzles 21 to the outside.

[0048] The length 21Z of the nozzle 21 in the depth direction is 70 to 120 μm. The diameter of the nozzle 21 on the discharge side is 10 to 30 μm. When viewed in cross section, the angle between the side surface of the nozzle 21 and the X axis is 70 to 80 degrees.

[0049] The longitudinal length 31X of the pressure chamber 31 is, for example, 300 to 500 μm. The lateral length 31Y of the pressure chamber 31 is, for example, 60 to 80 μm. The depth direction length 31Z of the pressure chamber 31 is, for example, 50 to 100 μm. The depth direction length 31Z of the pressure chamber 31 may be, for example, shorter than the depth direction length 21Z of the nozzle 21. This shortens the distance from the upper surface of the pressure chamber 31 to the upper surface of the nozzle 21, making it possible to reduce the possibility of scattering in the planar direction in the pressure chamber 31. Therefore, the liquid ejection head 1 according to this embodiment can efficiently utilize pressure waves to eject liquid. Furthermore, since the depth direction length 21Z of the nozzle 21 is large, the direction of the pressure wave can be regulated. Therefore, the liquid ejection head 1 according to this embodiment can efficiently utilize pressure waves to eject liquid.

[0050] The multiple first apertures 32 are through holes that penetrate the single crystal silicon substrate 33 in the Z-axis direction, and are each connected to one longitudinal end of the multiple pressure chambers 31. The first aperture 32 connected to the pressure chamber 31 located on the positive X-axis side is connected to the end of the pressure chamber 31 on the negative X-axis side. The first aperture 32 connected to the pressure chamber 31 located on the negative X-axis side is connected to the end of the pressure chamber 31 on the positive X-axis side. Liquid is stored inside the first aperture 32, just like inside the pressure chamber 31. When viewed in plan, the first aperture 32 includes a portion where the width in the Y-axis direction, i.e., the flow path width, is narrower than that of the pressure chamber 31, and therefore functions as a so-called throttle.

[0051] The diaphragm 34 is located on a single crystal silicon substrate 33. The diaphragm 34 is also located above the pressure chambers 31 and the first apertures 32. Examples of materials for the diaphragm 34 include Si and SiO2. The thickness of the diaphragm 34 may be 1 μm or more and 2 μm or less.

[0052] The plurality of piezoelectric elements 35 are positioned on the vibration plate 34 corresponding to the plurality of pressure chambers 31. The plurality of piezoelectric elements 35 are provided in a one-to-one relationship with the plurality of pressure chambers 31. When a voltage is applied to the piezoelectric elements 35, the piezoelectric elements 35 are displaced. As the piezoelectric elements 35 are displaced, the vibration plate 34 positioned above the pressure chambers 31 is also displaced. As a result, pressure is applied to the liquid in the pressure chambers 31. This causes the liquid to be ejected from the pressure chambers 31 through the nozzles 21.

[0053] The piezoelectric element 35 includes a common electrode 351, a piezoelectric body 352, and an individual electrode 353. In the piezoelectric element 35 according to this embodiment, the common electrode 351 is located on the diaphragm 34, the piezoelectric body 352 is located on the common electrode 351, and the individual electrode 353 is located on the piezoelectric body 352. However, this is not limiting. For example, the order of the common electrode 351 and the individual electrode 353 from the diaphragm 34 may be reversed. Specifically, the individual electrode 353, the piezoelectric body 352, and the common electrode 351 may be provided on the diaphragm 34 in this order. Furthermore, the piezoelectric element 35 may have an adhesion layer such as Ti between the common electrode 351 and the diaphragm 34. The piezoelectric element 35 may also have adhesion layers such as LaNiO3 between the common electrode 351 and the piezoelectric body 352 and between the piezoelectric body 352 and the individual electrode 353.

[0054] The common electrode 351 according to this embodiment is provided in common to the multiple pressure chambers 31. The thickness of the common electrode 351 according to this embodiment may be set to 0.05 μm or more and 1 μm or less. The common electrode 351 may be made of a metal material such as Pt, for example.

[0055] Although the piezoelectric element 352 according to this embodiment is individually provided corresponding to each of the pressure chambers 31, this is not limiting. For example, the piezoelectric element 352 may be provided in common to the pressure chambers 31, similar to the common electrode 351. The portion of the piezoelectric element 352 sandwiched between the individual electrode 353 and the common electrode 351 is polarized in the thickness direction of the piezoelectric element 352 in the Z-axis direction. Therefore, for example, when a voltage is applied in the polarization direction of the piezoelectric element 352 by the individual electrode 353 and the common electrode 351, the piezoelectric element 352 contracts in the direction along the diaphragm 34. This contraction is restricted by the diaphragm 34. As a result, the piezoelectric element 352 is displaced so as to convexly protrude toward the pressure chamber 31. As the piezoelectric element 352 displaces, the diaphragm 34 positioned above the pressure chamber 31 is also displaced. As a result, pressure is applied to the liquid in the pressure chamber 31. The thickness of the piezoelectric element 352 may be 0.5 μm or more and 5 μm or less. The piezoelectric body 352 may be made of, for example, Pb(Zr,Ti)O3, NaNbO3, BaTiO3, (BiNa)NbO3, or BiNaNB5O. 15Examples of suitable materials include ceramic materials having ferroelectricity such as ferroelectric ceramics.

[0056] The individual electrodes 353 are individually provided corresponding to the pressure chambers 31. The thickness of the individual electrodes 353 may be set to be 0.05 μm or more and 1 μm or less. The individual electrodes 353 may be made of a metal material such as Pt, for example.

[0057] The support member 40 is located on the actuator member 30. The support member 40 has a predetermined thickness that is thicker in the Z-axis direction than the actuator member 30, and has the function of supporting the actuator member 30. The support member 40 includes a plurality of second apertures 41. The support member 40 is made of single crystal silicon.

[0058] The multiple second apertures 41 are through holes that pass through the support member 40 in the Z-axis direction, and are respectively connected to the multiple first apertures 32. The multiple second apertures 41 are respectively connected to the multiple pressure chambers 31 via the multiple first apertures 32. The second apertures 41 function as so-called throttles, similar to the first apertures 32. Furthermore, the multiple second apertures 41 are located at the center of the support member 40 in the X-axis direction when viewed in a plan view.

[0059] The pressure chamber 31, the first aperture 32, and the second aperture 41 are filled with liquid. When pressure is applied to the pressure chamber 31 by the piezoelectric element 35, liquid is supplied from the pressure chamber 31 to the nozzle 21 and is ejected from the nozzle 21. In addition, the pressure chamber 31 is replenished with liquid from the second aperture 41 via the first aperture 32.

[0060] 6, 7, 8, and 9 show an example of the configuration of the liquid ejection head 1, and the liquid ejection head 1 may further include members other than those shown in FIGS.

[0061] The configuration of the common flow path member 3 will be described with reference to Figures 10 and 11. Figure 10(a) is a plan view showing the common flow path member 3. Figure 10(b) is a plan view showing only the first common flow path member 301. Figure 10(c) is a plan view showing only the second common flow path member 302. Figure 11 is a cross-sectional view taken along line III-III shown in Figure 10(a).

[0062] As described above, the common flow path member 3 has a common flow path 300 that supplies liquid to the multiple discharge members 2. The common flow path 300 has branch flow paths 310 and a unified flow path 320. The branch flow path 310 has a first branch flow path 311 and a second branch flow path 321.

[0063] The first common flow path member 301 has first branch flow paths 311. The first branch flow paths 311 are through holes that penetrate the first common flow path member 301 in the Z-axis direction. Within the common flow path member 3, there are four first branch flow paths 311 on the positive X-axis direction side and four on the negative X-axis direction side. Furthermore, the four first branch flow paths 311 on the positive X-axis direction side are positioned within the common flow path member 3 so as to be aligned between the four first common flow path members 301 on the negative X-axis direction side. The multiple first common flow path members 301 are arranged in a staggered pattern within the common flow path member 3.

[0064] The second common flow path member 302 has a plurality of second branch flow paths 321 , a combined flow path 320 , and an inlet portion 322 .

[0065] Each of the multiple second branch flow paths 321 is located on the negative Z-axis side of the second common flow path member 302. Each of the multiple second branch flow paths 321 opens to the lower surface of the second common flow path member 302 and connects to each of the multiple first branch flow paths 311. Therefore, like the first branch flow paths 311, the common flow path member 3 has four second branch flow paths 321 on the positive X-axis side and four on the negative X-axis side. The four second branch flow paths 321 on the positive X-axis side are located in the common flow path member 3 so as to be aligned between the four second branch flow paths 321 on the negative X-axis side. In other words, the multiple second branch flow paths 321 are arranged in a staggered pattern in the common flow path member 3. In a plan view, the area of ​​each second branch flow path 321 is larger than the area of ​​each first branch flow path 311. In a cross-sectional view, the width of each first branch flow path 321 in the X-axis direction is smaller than the width of each second branch flow path 321 in the X-axis direction. Therefore, in the liquid ejection head 1 according to this embodiment, the liquid flows quickly from upstream to downstream in the branch flow path 310, making the liquid flow more easily.

[0066] The integrated channel 320 is located above each of the branch channels 310. The integrated channel 320 extends from the end of the second common channel member 302 on the positive Y-axis side to the end on the negative Y-axis side. In a plan view, the integrated channel 320 overlaps with the branch channels 310 and extends in a meandering manner in the Y-axis direction. The width of the integrated channel 320 located above the branch channels 310 in the X-axis direction is greater than the width of the branch channels 310 in the X-axis direction. The height of the integrated channel 320 in the Z-axis direction is greater than the height of the branch channels 310 in the Z-axis direction. Therefore, in the liquid ejection head 1 according to this embodiment, the volume of the integrated channel 320 is large, and therefore the volume of the common channel 300 is also large. Therefore, the liquid ejection head 1 according to this embodiment is capable of supplying a large amount of liquid to the common channel 300.

[0067] In cross section, the combined channel 320 located on the positive X-axis side has a rectangular shape. The combined channel 320 has curved corners located on the negative X-axis and positive Z-axis sides.

[0068] On the other hand, when viewed in cross section, the shared channel 320 located on the negative X-axis side also has a rectangular shape. The corners of this shared channel 320 located on both the positive X-axis and positive Z-axis sides have curved outer peripheries.

[0069] The inlet section 322 opens in the positive direction of the Z axis of the second common flow path member 302 and is connected to the shared flow path 320. The inlet section 322 is located at the end of the second common flow path member 302 on the negative side of the Y axis, but is not limited to this. The inlet section 322 may be located in the center of the second common flow path member 302 in the Y axis direction or at the end of the second common flow path member 302 on the positive side of the Y axis. Liquid flows into the shared flow path 320 from outside the common flow path member 3 via the inlet section 322. The common flow path member 3 may also be provided with a discharge section that discharges the liquid to the outside.

[0070] The configurations of the discharge member 2 and the common flow path member 3 will be described with reference to Figures 12 and 13. Figure 12 is a cross-sectional view taken along line IV-IV in Figure 3, showing only the discharge member 2 and the common flow path member 3 extracted from the liquid discharge head 1. Figure 13 is an enlarged view of region V shown in Figure 12.

[0071] The discharge member 2 includes a nozzle 21, a pressure chamber 31, a piezoelectric element 35, and an individual flow path 50.

[0072] In the liquid ejection head 1 according to this embodiment, the individual flow paths 50 include a first aperture 32 and a second aperture 41. The first aperture 32 is connected to the pressure chamber 31. The second aperture 41 is connected to the common flow path 300. The second aperture 41 has an opening 51 that connects to the common flow path 300.

[0073] The nozzles 21, pressure chambers 31, individual flow paths 50, and common flow path 300 are filled with liquid. Pressure is applied to the pressure chambers 31 due to displacement of the piezoelectric elements 35. Then, liquid is supplied from the pressure chambers 31 to the nozzles 21, and the liquid is ejected from the nozzles 21.

[0074] The pressure waves generated in the pressure chambers 31 by the displacement of the piezoelectric elements 35 spread radially within the pressure chambers 31 from the part where the piezoelectric elements 35 are located. Of the radially spreading pressure waves, those that travel from the pressure chambers 31 toward the nozzles 21 cause liquid to be ejected from the nozzles 21. Meanwhile, a portion of the pressure waves that spread in a planar direction rather than toward the nozzles 21, or a portion of the pressure waves reflected by the wall surfaces of the pressure chambers 31, travel through the individual flow paths 50 and propagate to the common flow path 300 via the openings 51.

[0075] In the liquid ejection head 1 according to this embodiment, the common flow path 300 supplies liquid to a plurality of ejection members 2 in common, and therefore the volume of the common flow path 300 is larger than in an embodiment in which liquid is supplied individually to one ejection member 2. In other words, the common flow path 300 according to this embodiment has a large volume compliance. Here, volume compliance is the rate of change in volume with respect to a certain pressure change. In other words, the larger the volume compliance of a flow path, the easier it is to absorb pressure waves. Therefore, in the liquid ejection head 1 according to this embodiment, even if part of the pressure wave generated in the pressure chamber 31 is propagated to the common flow path 300 through the individual flow paths 50, the large volume compliance of the common flow path 300 makes it easy for the common flow path 300 to absorb this pressure wave.

[0076] Furthermore, in the liquid ejection head 1 according to this embodiment, a space A for locating the liquid is formed between the opening 51 and the upper surface 330 of the common flow channel 300. Here, the space A is the area surrounded by the dashed line in FIG. 12. Note that a part of the space A is also shown in FIG. 13. The space A according to this embodiment is an area that extends from the opening 51 to the upper surface 330 while maintaining the size of the opening 51. Here, the direction in which the space A extends from the opening 51 to the upper surface 330 is the Z-axis direction. Furthermore, the upper surface 330 of the common flow channel 300 is the wall surface of the common flow channel 300 that is located on the positive side of the Z-axis. The nozzle 21 is arranged in a negative Z-axis direction with respect to the pressure chamber 31. 12, the upper surface 330 of the common flow channel 300 is located on the Z-axis positive direction side, which is the opposite direction to the pressure chamber 31. In FIG. 12, the upper surface 330 of the common flow channel 300 is indicated by a thick line. In other words, when a straight line is extended in the positive direction of the Z axis from any point on the upper surface 330 of the common flow channel 300, the wall surface of the common flow channel 300 is not located on this straight line.

[0077] In the liquid ejection head 1 according to this embodiment, a portion of the pressure wave generated in the pressure chamber 31 propagates through the liquid located in the space A. That is, since the space A according to this embodiment is filled only with liquid, there is nothing to reflect the pressure wave propagated to the common flow path 300. For example, if a wall surface of the common flow path 300 were located between the opening 51 of an individual flow path 50 and the upper surface 330 of the common flow path 300, the pressure wave propagated to the common flow path 300 would be reflected by the wall surface, and the reflected pressure wave could propagate through another individual flow path 50 to another pressure chamber 31. Furthermore, the reflected pressure wave could return to the original pressure chamber 31. If the pressure wave propagates to another pressure chamber 31 or if the pressure wave returns to the original pressure chamber 31, the ejection characteristics of the liquid ejection head 1 would be affected.

[0078] In the liquid ejection head 1 according to this embodiment, a pressure wave propagated to the common flow path 300 propagates through the liquid located in the space A and travels directly toward the upper surface 330 of the common flow path 300 without being reflected. Because the pressure wave travels directly toward the upper surface 330 of the common flow path 300 without being reflected, the pressure wave propagating through the liquid is attenuated as it travels toward the upper surface 330. Furthermore, in a cross-sectional view of the liquid ejection head 1 according to this embodiment, the distance between the opening 51 and the upper surface 330 of the common flow path 300 is greater than the distance in the width direction of the common flow path 300. Specifically, the distance between the opening 51 and the upper surface 330 of the common flow path 300 is greater than the distance in the X-axis direction of the branch flow paths 310 and the distance in the X-axis direction of the integrated flow path 320. Furthermore, the distance between the opening 51 and the upper surface 330 of the common flow path 300 is greater than the distance between the opening 51 and the side surface of the common flow path 300, and the opening 51 faces the upper surface 330 of the common flow path 300. For this reason, in this embodiment, the length of space A is inevitably increased. In this way, the amount of liquid located in space A in the common flow path 300 increases, and the pressure wave propagated to the common flow path 300 is attenuated as it propagates through the liquid. For this reason, the liquid ejection head 1 according to this embodiment can reduce the possibility that a portion of the pressure wave generated in one pressure chamber 31 will propagate to another pressure chamber 31 or return to the original pressure chamber 31. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that the pressure wave will affect the ejection characteristics.

[0079] Here, the discharge member 2 has a first surface 201 and a second surface 202 located on the opposite side of the first surface 201. A plurality of nozzles 21 are provided on the first surface 201, and an opening 51 is provided on the second surface 202. The common flow path member 3 is located on the second surface 202 of each of the plurality of discharge members 2. In the liquid discharge head 1, a space A is formed between the opening 51 and the upper surface 330 of the common flow path 300 in each of the plurality of discharge members 2. Therefore, in the liquid ejection head 1 according to this embodiment, a portion of the pressure wave generated in each of the pressure chambers 31 of the plurality of ejection members 2 propagates through the liquid located in the space A. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that a portion of the pressure wave generated in each of the pressure chambers 31 of the plurality of ejection members 2 propagates to another pressure chamber 31 or returns to the original pressure chamber 31.

[0080] The common flow path 300 includes a plurality of branch flow paths 310 and a unified flow path 320. The branch flow paths 310 supply liquid to each of the plurality of discharge members 2. The unified flow path 320 is located above each of the branch flow paths 310 and supplies liquid to all of the branch flow paths 310 in common. The opening 51 is connected to the branch flow paths 310. An upper surface 330 of the common flow path 300 is an upper surface 331 of the unified flow path 320.

[0081] The liquid ejection head 1 according to this embodiment is provided with a branch flow path 310 between the joint flow path 320 and the ejection member 2. In the liquid ejection head 1 according to this embodiment, the pressure of one ejection member 2 is A portion of the pressure wave generated in the chamber 31 is propagated to the branch flow path 310 via the opening 51. The pressure wave propagated to the branch flow path 310 is further propagated to another discharge member 2 via the integrated flow path 320 and another branch flow path 310. In other words, by providing the branch flow path 310, the pressure wave propagated to the branch flow path 310 is not propagated directly to another discharge member 2, thereby reducing the possibility that the pressure wave will propagate to the pressure chamber 31 of another discharge member 2. Therefore, the liquid discharge head 1 according to this embodiment can reduce the possibility that a portion of the pressure wave generated in the pressure chamber 31 of one discharge member 2 will propagate to the pressure chamber 31 of another discharge member 2, thereby reducing the possibility that the pressure wave will affect the discharge characteristics.

[0082] The branch flow path 310 has a first connection port 312 that connects to the shared flow path 320, and the shared flow path 320 has a second connection port 3201 that connects to the first connection port 312. In the liquid ejection head 1 according to this embodiment, the width of the second connection port 3201 is the same as or larger than the width of the first connection port 312, when viewed in cross section. Figure 12 illustrates an example in which the width of the second connection port 3201 is larger than the width of the first connection port 312. Here, when viewed in cross section, the width of the second connection port 3201 and the width of the first connection port 312 are widths in the X-axis direction.

[0083] In the liquid ejection head 1 according to this embodiment, when viewed in cross section, the width of the second connection port 3201 is the same as or larger than the width of the first connection port 312. This increases the likelihood that air bubbles generated in the branch flow paths 310 or the discharge member 2 will rise and be discharged into the integrated flow path 320. Therefore, the liquid ejection head 1 according to this embodiment can reduce the likelihood that air bubbles generated in the branch flow paths 310 or the discharge member 2 will accumulate in the branch flow paths 310 or the discharge member 2. The branch flow paths 310 are located closer to the discharge member 2 than the integrated flow path 320, and air bubbles have a greater effect on the ejection characteristics. Therefore, the liquid ejection head 1 according to this embodiment can reduce the likelihood that air bubbles will accumulate in the branch flow paths 310, which have a greater effect on the ejection characteristics, and therefore reduce the likelihood that the ejection characteristics will be affected.

[0084] The branch flow path 310 includes a first branch flow path 311 and a second branch flow path 321. The first branch flow path 311 is located on the discharge member 2 and supplies liquid to the discharge member 2. The second branch flow path 321 is located on the first branch flow path 311 and supplies liquid to the first branch flow path 311. The first branch flow path 311 has a third connection port 3111 that connects to the second branch flow path 321, and the second branch flow path 321 has a fourth connection port 3211 that connects to the third connection port 3111. When viewed in cross section, the liquid discharge head 1 according to this embodiment has a width of the fourth connection port 3211 that is larger than the width of the third connection port 3111 in the X-axis direction.

[0085] The liquid ejection head 1 according to this embodiment can reduce the possibility that bubbles generated in the first branch flow channel 311 or the ejection member 2 will accumulate in the first branch flow channel 311. Furthermore, the liquid ejection head 1 according to this embodiment can reduce the possibility that the width of the branch flow channel 310 in the X-axis direction from the first connection port 312 to the portion connecting to the opening 51 will suddenly decrease, thereby reducing the possibility that the flow rate of the liquid in the branch flow channel 310 will suddenly change. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility of bubbles being generated due to a sudden change in the flow rate of the liquid in the branch flow channel 310.

[0086] In the liquid ejection head 1 according to this embodiment, the width of the second connection port 3201 may be smaller than the width of the first connection port 312 when viewed in cross section. Here, part of the pressure wave generated in the pressure chamber 31 of one ejection member 2 is propagated to the branch flow channel 310 via the opening 51. In the liquid ejection head 1 according to this embodiment, the width of the second connection port 3201 is smaller than the width of the first connection port 312, so the pressure wave is less likely to propagate from the branch flow channel 310 to the joint flow channel 320. Therefore, in the liquid ejection head 1 according to this embodiment, it is possible to reduce the possibility that part of the pressure wave generated in the pressure chamber 31 of one ejection member 2 will propagate to the pressure chamber 31 of another ejection member 2. This reduces the possibility of affecting the ejection characteristics.

[0087] In the liquid ejection head 1 according to this embodiment, the height of the shared channel 320 is greater than the height of each of the branch channels 310. In the liquid ejection head 1 according to this embodiment, by making the height of the shared channel 320 greater than the height of each of the branch channels 310, the volume of the common channel 300 is increased, and therefore the volume compliance of the common channel 300 is increased. Therefore, in the liquid ejection head 1 according to this embodiment, even if a portion of a pressure wave generated in a pressure chamber 31 is propagated to the common channel 300 through the individual channels 50, the large volume compliance of the common channel 300 makes it easy for the common channel 300 to absorb this pressure wave. Therefore, in the liquid ejection head 1 according to this embodiment, it is possible to reduce the possibility that a portion of a pressure wave generated in one pressure chamber 31 will propagate to another pressure chamber 31 or return to the original pressure chamber 31.

[0088] In the liquid ejection head 1 according to this embodiment, the height of the shared channel 320 may be lower than the height of each of the branch channels 310. In this liquid ejection head 1, a portion of a pressure wave generated in a pressure chamber 31 of one ejection member 2 is propagated to the branch channel 310. The pressure wave propagated to the branch channel 310 is further propagated to another ejection member 2 via the shared channel 320 and another branch channel 310. In this liquid ejection head 1, because the height of the branch channel 310 is high, the pressure wave propagated to the branch channel 310 can be reduced in likelihood of being propagated to the shared channel 320. Therefore, it is possible to reduce the likelihood that a portion of a pressure wave generated in a pressure chamber 31 of one ejection member 2 will propagate to a pressure chamber 31 of another ejection member 2, thereby reducing the likelihood of the pressure wave affecting the ejection characteristics.

[0089] As shown in Figure 14, the liquid ejection head 1 of this embodiment may have a branch flow path 310 having a fifth connection port 3101 that connects to the opening 51, and when viewed in cross section, may have a configuration in which the width decreases as it moves from the first connection port 312 to the fifth connection port 3101.

[0090] In such a liquid ejection head 1, the width of the branch flow path 310 does not decrease abruptly, thereby reducing the possibility of a sudden change in the flow rate of the liquid flowing through the branch flow path 310. Therefore, in such a liquid ejection head 1, it is possible to reduce the generation of bubbles due to a sudden change in the flow rate of the liquid in the branch flow path 310.

[0091] Furthermore, the liquid ejection head 1 may have a configuration in which the branch flow path 310 has a width that increases from the first connection port 312 toward the fifth connection port 3101 when viewed in cross section.

[0092] In such a liquid ejection head 1, the width of the first connection port 312 is small, so that pressure waves are less likely to propagate from the branch flow paths 310 to the joint flow path 320. Therefore, in such a liquid ejection head 1, it is possible to reduce the possibility that part of the pressure wave generated in the pressure chamber 31 of one ejection member 2 will propagate to the pressure chamber 31 of another ejection member 2, thereby reducing the possibility that the pressure wave will affect the ejection characteristics.

[0093] In the liquid ejection head 1 according to this embodiment, the area of ​​the opening 51 in a plan view is smaller than the area in a cross-sectional view of the pressure chamber 31. The area in a cross-sectional view of the pressure chamber 31 is the cross-sectional area of ​​the pressure chamber 31 as seen from the X-axis direction.

[0094] In the liquid ejection head 1 according to this embodiment, the area of ​​the opening 51 in a plan view is smaller than the area of ​​the pressure chamber 31 in a cross-sectional view, thereby reducing the possibility that a part of the pressure wave generated in one pressure chamber 31 will be propagated to the common flow path 300 via the opening 51 through the individual flow path 50. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that a part of the pressure wave generated in one pressure chamber 31 will be propagated to another pressure chamber 31. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that the ejection characteristics will be affected. can be reduced.

[0095] In the liquid ejection head 1 according to this embodiment, two restrictions, a first aperture 32 and a second aperture 41, are provided in the individual flow path 50. When viewed in cross section, the area of ​​the first aperture 32 and the area of ​​the second aperture 41 are smaller than the area of ​​the pressure chamber 31. Furthermore, the longitudinal direction of the first aperture 32 is the X-axis direction, and the longitudinal direction of the second aperture 41 is the Z-axis direction, and the longitudinal direction of the first aperture 32 is different from the longitudinal direction of the second aperture 41.

[0096] Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that a part of the pressure wave generated in the pressure chamber 31 will propagate to the common flow path 300. Furthermore, in the liquid ejection head 1 according to this embodiment, when viewed in cross section, the area of ​​the first aperture 32 and the area of ​​the second aperture 41 are smaller than the area of ​​the pressure chamber 31, so it is possible to reduce the possibility that a part of the pressure wave generated in one pressure chamber 31 will propagate through the individual flow path 50 and into the common flow path 300 via the opening 51. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that the ejection characteristics will be affected.

[0097] The shape of the common flow path 300 will be described with reference to Figures 15 and 16. Figure 15 is a plan view showing the common flow path member 3 and the discharge member 2. Figure 16 is a cross-sectional view taken along line VV shown in Figure 15.

[0098] The integrated flow path 320 extends in a serpentine manner from the end on the positive Y-axis side to the end on the negative Y-axis side of the common flow path member 3. Furthermore, the first branch flow paths 311 and the second branch flow paths 321 that make up the branch flow paths 310 are provided in the common flow path member 3 with four on the positive X-axis side and four on the negative X-axis side, respectively.

[0099] When viewed in a plan view, the common flow path member 3 includes portions where the branch flow paths 310 and the integrated flow path 320 are not located between the four discharge members 2 on the positive side of the X-axis and between the four discharge members 2 on the negative side of the X-axis. That is, when viewed in a plan view, the common flow path member 3 according to this embodiment includes portions 360 where the common flow path 300 is not located between adjacent discharge members 2. Therefore, the liquid discharge head 1 according to this embodiment can further reduce the possibility that part of the pressure waves generated in the multiple pressure chambers 31 of one discharge member 2 will propagate to the pressure chambers 31 of the adjacent discharge member 2, thereby reducing the possibility of affecting the discharge characteristics. Note that the common flow path member 3 according to this embodiment has a solid portion 360 where the common flow path 300 is not located between adjacent discharge members 2.

[0100] (Second embodiment) A liquid ejection head 1a according to a second embodiment will now be described. In the description of the liquid ejection head 1a according to this embodiment, only the differences from the liquid ejection head 1 according to the first embodiment will basically be described. Matters not specifically mentioned may be considered to be the same as those in the first embodiment or may be inferred from those in the first embodiment.

[0101] A liquid ejection head 1a according to this embodiment will be described with reference to Fig. 17. Fig. 17 is a cross-sectional view of the liquid ejection head 1a according to this embodiment. Fig. 17 is a diagram in which only the ejection member 2, common flow path member 3a, protective member 4, and damper film 60 are extracted from the liquid ejection head 1a.

[0102] The space between the first opening 51a and the upper surface 330a of the common flow channel 300a is a space A for the liquid to be placed in. Here, the space A is the region surrounded by the dashed line in FIG.

[0103] In the liquid ejection head 1a according to this embodiment, the common flow path 300a supplies liquid in common to a plurality of ejection members 2, and therefore the volume of the common flow path 300a is larger than in an embodiment in which liquid is supplied individually to one ejection member 2. Therefore, in the liquid ejection head 1a according to this embodiment, even if a part of the pressure wave generated in the pressure chamber 31 by the displacement of the piezoelectric element 35 is propagated to the common flow path 300a through the individual flow paths 50, the large volume compliance of the common flow path 300a makes it easy for this pressure wave to be absorbed by the common flow path 300a.

[0104] In the liquid ejection head 1a according to this embodiment, a portion of the pressure wave generated in the pressure chamber 31 propagates through the liquid located in the space A. Therefore, in the liquid ejection head 1a according to this embodiment, the pressure wave travels directly toward the upper surface 330a of the common flow path 300a without being reflected, and the pressure wave is attenuated as it travels toward the upper surface 330a. Therefore, the liquid ejection head 1a according to this embodiment can reduce the possibility that a portion of the pressure wave generated in one pressure chamber 31 propagates to another pressure chamber 31 or returns to the original pressure chamber 31. Therefore, the liquid ejection head 1a according to this embodiment can reduce the possibility that the pressure wave will affect the ejection characteristics.

[0105] Furthermore, in the liquid ejection head 1a according to this embodiment, at least a portion of the upper surface 330a facing the first opening 51a is inclined with respect to the facing direction. Here, the facing direction refers to the direction in which the space A extends from the first opening 51a to the upper surface 330a. In the liquid ejection head according to this embodiment, the facing direction is the Z-axis direction. Therefore, in the liquid ejection head 1a according to this embodiment, there is a high possibility that a pressure wave reflected by the upper surface 330a will travel toward the side surface 303 of the common flow path 300a. Therefore, the liquid ejection head 1a according to this embodiment can further reduce the possibility that a portion of a pressure wave generated in one pressure chamber 31 will propagate to another pressure chamber 31 or return to the original pressure chamber 31. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility that the pressure wave will affect the ejection characteristics.

[0106] The common flow path member 3a according to this embodiment has a second opening 341, which is an opening in a portion of the side surface 340. The second opening 341 is connected to the common flow path 300a. Furthermore, the portion of the upper surface 330a facing the first opening 51a also faces the second opening 341. In other words, the second opening 341 is located in a region of the upper surface 330a that extends perpendicular to the first opening 51a. Furthermore, the second opening 341 is covered by a damper film 60. The damper film 60 is made of a material that has low rigidity and flexibility.

[0107] Because the portion of the upper surface 330a according to this embodiment that faces the first opening 51a also faces the second opening 341, in the liquid ejection head 1a according to this embodiment, there is a high possibility that the pressure waves reflected from the upper surface 330a of the common flow path 300a will be directed toward the damper film 60 that covers the second opening 341. The liquid ejection head 1a according to this embodiment can absorb and reduce the pressure waves that reach the damper film 60 that covers the second opening 341 with this damper film 60. Therefore, the liquid ejection head 1a according to this embodiment can further reduce the possibility that the pressure waves generated in one pressure chamber 31 will propagate to other pressure chambers 31, thereby reducing the possibility that the ejection characteristics will be affected.

[0108] Furthermore, in the liquid ejection head 1a according to this embodiment, the protective member 4 faces the damper film 60 across the space 70. Therefore, in the liquid ejection head 1a according to this embodiment, the damper film 60 can reduce external impacts due to the protective member 4. Therefore, in the liquid ejection head 1a according to this embodiment, the possibility of the damper film 60 peeling off or breaking can be reduced. Furthermore, in the liquid ejection head 1a according to this embodiment, the protective member 4 is made of metal and has high rigidity, so the protective member 4 can further reduce external impacts on the damper film 60.

[0109] (Third embodiment) A liquid ejection head 1b according to a third embodiment will now be described. In the description of the liquid ejection head 1b according to this embodiment, basically, only the differences from the liquid ejection head 1 according to the first embodiment will be described. Matters not specifically mentioned may be considered to be the same as those in the first embodiment or may be inferred from those in the first embodiment.

[0110] A liquid ejection head 1b according to this embodiment will be described with reference to Fig. 18. Fig. 18 is a cross-sectional view of the liquid ejection head 1b according to this embodiment. Fig. 18 is a diagram showing only the ejection member 2, the common flow path member 3b, the protective member 4, and the damper film 60a.

[0111] The space between the first opening 51a and the upper surface 330b of the common flow channel 300b is a space A for the liquid to be positioned in. Here, the space A is the region indicated by the dashed line in FIG.

[0112] In the liquid ejection head 1b according to this embodiment, the common flow path 300b supplies liquid in common to a plurality of ejection members 2, and therefore the volume of the common flow path 300b is larger than in an embodiment in which liquid is supplied individually to one ejection member 2. Therefore, in the liquid ejection head 1b according to this embodiment, even if a part of the pressure wave generated in the pressure chamber 31 by the displacement of the piezoelectric element 35 is propagated to the common flow path 300b through the individual flow paths 50, the large volume compliance of the common flow path 300b makes it easy for the common flow path 300b to absorb this pressure wave.

[0113] In the liquid ejection head 1b according to this embodiment, a portion of the pressure wave generated in the pressure chamber 31 propagates through the liquid located in the space A. Therefore, in the liquid ejection head 1b according to this embodiment, the pressure wave travels directly toward the upper surface 330b of the common flow path 300b without being reflected, and the pressure wave is attenuated as it travels toward the upper surface 330b. Therefore, the liquid ejection head 1b according to this embodiment can reduce the possibility that a portion of the pressure wave generated in one pressure chamber 31 propagates to another pressure chamber 31 or returns to the original pressure chamber 31. Therefore, the liquid ejection head 1b according to this embodiment can reduce the possibility that the pressure wave will affect the ejection characteristics.

[0114] Furthermore, the common flow path member 3b according to this embodiment has a third opening 351, which is an opening in a portion of an upper surface 350 of the common flow path member 3b. The third opening 351 is connected to the common flow path 300b. Furthermore, the third opening 351 is covered by a damper film 60a. That is, in the liquid ejection head 1 according to this embodiment, the lower surface of the damper film 60a forms the upper surface 330b of the common flow path 300b.

[0115] Therefore, in the liquid ejection head 1 according to this embodiment, the pressure wave propagated to the common flow path 300 propagates through the liquid located in the space A and heads directly toward the damper film 60a covering the third opening 351 without being reflected. The liquid ejection head 1a according to this embodiment is able to absorb and reduce the pressure wave that reaches the damper film 60a by this damper film 60a. Therefore, the liquid ejection head 1b according to this embodiment can further reduce the possibility that a pressure wave generated in one pressure chamber 31 will propagate to another pressure chamber 31, thereby reducing the possibility that the pressure wave will affect the ejection characteristics.

[0116] Furthermore, in the liquid ejection head 1b according to this embodiment, the protective member 4 faces the damper film 60a via a space 70a. Therefore, in the liquid ejection head 1b according to this embodiment, the damper film 60a can reduce external impacts by the protective member 4. Therefore, in the liquid ejection head 1b according to this embodiment, the possibility of the damper film 60a peeling off or breaking can be reduced. Furthermore, in the liquid ejection head 1b according to this embodiment, the protective member 4 is made of metal and has high rigidity, so the damper film 60a can be held by the protective member 4. External impacts can be further reduced.

[0117] The first to third embodiments described above may be combined as appropriate. [Explanation of symbols]

[0118] 1, 1a, 1b Liquid ejection head 2 Discharge member 3, 3a, 3b Common flow path member 21 nozzles 31 Pressure Chamber 32 First Aperture 41 Second Aperture 50 individual channels 51 Opening 51a 1st opening 60, 60a damper membrane 100 Printer (recording device) 108 Control Unit 201 First surface of discharge member 202 second surface of discharge member 300, 300a, 300b common flow path 310 Branch Channel 311 First branch channel 312 First Connection Port 321 Second branch channel 320, 320a Integrated flow channel 330, 330a, 330b Upper surface of common flow channel 331 Top of integrated channel 303 Side of common flow path 340 Side of common flow path member 341 Second Opening 350 Upper surface of common flow path member 351 Third Opening 3101 No. 5 Connection 3111 Third connection port 3201 Second connection port 3211 No. 4 Connection A Space

Claims

1. a plurality of ejection members each having a nozzle, a pressure chamber connected to the nozzle, and an individual flow path connected to the pressure chamber; a common flow path member having a common flow path for supplying liquid to the plurality of ejection members in common; Equipped with the individual flow paths include openings that connect to the common flow path, A space for liquid to be positioned is formed between the opening and the upper surface of the common flow channel. Liquid ejection head.

2. When viewed in cross section, the distance between the opening and the upper surface of the common flow channel is greater than the distance in the width direction of the common flow channel. The liquid ejection head according to claim 1 .

3. the discharge member includes a first surface and a second surface opposite the first surface; The nozzle is provided on the first surface, The second surface is provided with the opening, the common flow path member is located on the second surface of each of the plurality of discharge members, In each of the plurality of discharge members, the space is formed between the opening and the upper surface of the common flow path. The liquid ejection head according to claim 1 .

4. The common flow path is a plurality of branched flow paths for supplying liquid to the plurality of discharge members, respectively; a common channel located on the plurality of branch channels and for supplying a liquid to the plurality of branch channels; It has the opening is connected to the branch flow path, The upper surface is the upper surface of the integrated channel. The liquid ejection head according to claim 1 .

5. the branch flow path has a first connection port connected to the integrated flow path, the integrated flow path has a second connection port connected to the first connection port, When viewed in cross section, the width of the second connection port is the same as or larger than the width of the first connection port. The liquid ejection head according to claim 4 .

6. the branch flow path has a first branch flow path and a second branch flow path, the first branch flow path is located on the discharge member, the second branch flow path is located on the first branch flow path, the first branch flow path has a third connection port connected to the second branch flow path, the second branch flow path has a fourth connection port connected to the third connection port, When viewed in cross section, the width of the fourth connection port is greater than the width of the third connection port. The liquid ejection head according to claim 5 .

7. the branch flow path has a first connection port connected to the integrated flow path, the integrated flow path has a second connection port connected to the first connection port, When viewed in cross section, the width of the second connection port is greater than the width of the first connection port. The liquid ejection head according to claim 4 .

8. The height of the integrated flow path is greater than the height of each of the plurality of branch flow paths. The liquid ejection head according to claim 4 .

9. The branch flow path is a first connection port connected to the integrated flow path; a fifth connection port connected to the opening; It has When viewed in cross section, the branch flow path has a width that decreases from the first connection port toward the fifth connection port. The liquid ejection head according to claim 4 .

10. The area of ​​the opening in a plan view is smaller than the area of ​​the pressure chamber in a cross-sectional view. The liquid ejection head according to claim 1 .

11. The individual flow paths are a first aperture communicating with the pressure chamber; a second aperture communicating with the opening; It has When viewed in cross section, the area of ​​the first aperture and the area of ​​the second aperture are smaller than the area of ​​the pressure chamber; The longitudinal direction of the first aperture is different from the longitudinal direction of the second aperture. The liquid ejection head according to claim 1 .

12. When viewed from above, the common flow path member has a portion between the adjacent discharge members where the common flow path is not located. The liquid ejection head according to claim 1 .

13. At least a portion of the upper surface facing the opening is inclined with respect to the facing direction. The liquid ejection head according to claim 1 .

14. When the opening is a first opening, the common flow path member further has a second opening portion connected to the common flow path and having a side surface that is partially open, a portion of the upper surface facing the opening also facing the second opening, The second opening is covered with a damper membrane. The liquid ejection head according to claim 13.

15. When the opening is a first opening, the common flow path member further has a third opening portion connected to the common flow path and having an upper surface that is open in part, The third opening is covered with a damper membrane. The liquid ejection head according to claim 1 .

16. A liquid ejection head according to any one of claims 1 to 15, a moving unit that moves the liquid ejection head and a recording medium relative to each other; a control unit that controls the moving unit; Recording device.

Images