Liquid ejecting head, and recording device

Abstract

A liquid ejecting head (1) comprises a plurality of individual flow passages, and a common flow passage connected to the plurality of individual flow passages. Each of the plurality of individual flow passages comprises a nozzle (41), a liquid chamber (131) positioned above the nozzle (41), a first aperture (53) connected to the liquid chamber (131) in the direction of a side surface of the liquid chamber (131), and a second aperture (50) connected to the first aperture (53) and positioned above the first aperture (53). An actuator (30) is positioned above each of the plurality of liquid chambers (131). The cross-sectional area of the first aperture (53) is less than the cross-sectional area of the liquid chamber (131).

Description

Liquid dispensing head and recording device

[0001] This disclosure relates to a liquid dispensing head and a recording device.

[0002] A liquid ejection head that ejects liquid toward a recording medium is known (see, for example, Patent Document 1). In Patent Document 1, the ink supply path has at least a first flow path section, a second flow path section, and a third flow path section in order from the side closest to the common flow path along the ink supply direction, the first flow path section being a vertical flow path that allows ink supplied from the common flow path to flow upward into the second flow path section, and the third flow path section being a horizontal flow path that allows ink in the second flow path section to flow laterally out of the second flow path section.

[0003] Japanese Patent Publication No. 2011-51155

[0004] A liquid discharge head according to one aspect of the present disclosure comprises a plurality of individual channels and a common channel connected to the plurality of individual channels. Each of the plurality of individual channels has a nozzle, a liquid chamber located above the nozzle, a first aperture connected to the liquid chamber in the lateral direction of the liquid chamber, and a second aperture connected to the first aperture and located above the first aperture. An actuator is located above each of the plurality of liquid chambers. The cross-sectional area of ​​the first aperture is smaller than the cross-sectional area of ​​the liquid chamber.

[0005] Figure 1 is a schematic side view showing a printer according to one embodiment. Figure 2 is a schematic top view showing a printer according to one embodiment. Figure 3 is an exploded perspective view showing the schematic configuration of the liquid ejection head in steps. Figure 4 is an exploded perspective view showing the schematic configuration of the line head unit in steps. Figure 5 is a cross-sectional view along line A-A shown in Figure 3. Figure 6 is a perspective view showing a schematic configuration of a part of the MEMS chip. Figure 7 is a cross-sectional view showing the detailed configuration of the actuator substrate. Figure 8 is a diagram showing an example of a cross-sectional view along line B-B shown in Figure 7. Figure 9 is a schematic top view showing a part of the actuator substrate. Figure 10 is a cross-sectional view and a top view of the support substrate of the support substrate, actuator substrate and nozzle substrate of the liquid ejection head according to the first embodiment. Figure 11 is a diagram showing an example of the dimensions of each part shown in Figure 10. Figure 12 is a cross-sectional view and a top view of the support substrate of the support substrate, actuator substrate and nozzle substrate of the liquid ejection head according to the second embodiment.

[0006] The following describes in detail, with reference to the drawings, embodiments for implementing the liquid discharge head and recording device according to this disclosure (hereinafter referred to as "Embodiments"). However, this disclosure is not limited by these embodiments. Furthermore, each embodiment can be combined as appropriate, provided that the processing content is not inconsistent. Also, the same parts are denoted by the same reference numerals in each of the following embodiments, and redundant descriptions are omitted.

[0007] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations such as manufacturing accuracy or installation accuracy.

[0008] Furthermore, in the drawings referenced below, for the sake of clarity, mutually orthogonal X-axis, Y-axis, and Z-axis directions are sometimes defined, and a Cartesian coordinate system is shown with the positive Z-axis direction as the vertically upward direction.

[0009] The liquid ejection head has multiple individual channels corresponding to multiple nozzles, and liquid such as ink is ejected from each individual channel through each liquid chamber to each nozzle. The multiple individual channels are connected to each other via a common channel. Therefore, due to the pressurization of the piezoelectric element, a pressure wave generated in a liquid chamber connected to one individual channel may be transmitted to another individual channel via the common channel, resulting in so-called crosstalk. Crosstalk may affect printing performance.

[0010] A piezoelectric element is located above the liquid chamber. Due to the pressurization of the piezoelectric element, the pressure wave propagates toward the surface corresponding to the piezoelectric element in the liquid chamber and the lateral flow path located beside the liquid chamber. Therefore, if the longitudinal flow path between the lateral flow path and the common flow path is located below the lateral flow path, the pressure wave is likely to propagate directly from the lateral flow path to the longitudinal flow path. Thus, in conventional liquid discharge heads, the pressure wave generated in the liquid chamber located beside the third flow path section is likely to propagate from the third flow path section through the second flow path section to the first flow path section located below the second flow path section, and then from the first flow path section to the common flow path. For this reason, there is room for improvement in terms of crosstalk in conventional liquid discharge heads.

[0011] This disclosure provides a liquid dispensing head and a recording device capable of reducing the occurrence of crosstalk.

[0012] <Printer Configuration> First, an overview of the printer 100, which is an example of a recording device according to one embodiment, will be described with reference to Figures 1 and 2. Figure 1 is a schematic side view showing the printer 100 according to one embodiment. Figure 2 is a schematic top view showing the printer 100 according to one embodiment. The printer 100 according to one embodiment is, for example, a color inkjet printer.

[0013] As shown in Figure 1, the printer 100 includes a paper feed roller 101, guide rollers 102A to 102C, multiple transport rollers 103, a recovery roller 104, a head case 105, multiple frames 106, multiple liquid discharge heads 1, a dryer 107, and a coating machine 109. Furthermore, the printer 100 includes a sensor unit 108 and a control unit 200.

[0014] The control unit 200 controls the paper feed roller 101, guide rollers 102A to 102C, multiple transport rollers 103, recovery roller 104, head case 105, multiple frames 106, multiple liquid discharge heads 1, dryer 107, sensor unit 108, and coating machine 109.

[0015] The printer 100 records images or characters on the printing paper P by depositing droplets of liquid onto the paper P. The printing paper P is an example of a recording medium. Before use, the printing paper P is wound around the paper feed roller 101. The printer 100 then transports the printing paper P from the paper feed roller 101 to the inside of the head case 105 via the guide roller 102A and the coating machine 109.

[0016] The coating machine 109 uniformly applies the coating agent to the printing paper P. This allows the printing paper P to undergo surface treatment, thereby improving the print quality of the printer 100.

[0017] The head case 105 houses multiple transport rollers 103, multiple frames 106, and multiple liquid discharge heads 1. Inside the head case 105, a space is formed that is isolated from the outside, except for parts that are connected to the outside, such as the area where the printing paper P enters and exits.

[0018] The internal space of the head case 105 is controlled by the control unit 200, as needed, by at least one of the control factors such as temperature, humidity, and atmospheric pressure. The transport roller 103 transports the printing paper P to the vicinity of the liquid discharge head 1 inside the head case 105.

[0019] The frame 106 is a rectangular flat plate and is positioned close above the printing paper P being transported by the transport roller 103. Also, as shown in Figure 2, the frame 106 is positioned so that its longitudinal direction is perpendicular to the transport direction of the printing paper P. Inside the head case 105, multiple (for example, four) frames 106 are positioned along the transport direction of the printing paper P.

[0020] Liquid, such as ink, is supplied to the liquid ejection head 1 from a liquid tank (not shown). The liquid ejection head 1 ejects droplets supplied from the liquid tank.

[0021] The control unit 200 controls the liquid ejection head 1 based on data such as images or characters, and ejects droplets toward the printing paper P. The distance between the liquid ejection head 1 and the printing paper P is, for example, about 0.5 to 20 mm.

[0022] The liquid dispensing head 1 is fixed to the frame 106. The liquid dispensing head 1 is fixed to the frame 106, for example, at both ends in the longitudinal direction. The liquid dispensing head 1 is positioned so that its longitudinal direction is perpendicular to the direction in which the printing paper P is transported.

[0023] In other words, the printer 100 according to one embodiment is a so-called line printer in which a liquid ejection head 1 is fixed inside the printer 100. However, the printer 100 according to one embodiment is not limited to a line printer, but may also be a so-called serial printer. A serial printer is a printer that alternately performs the operation of recording while moving the liquid ejection head 1 back and forth in a direction intersecting the transport direction of the printing paper P, for example, in a nearly perpendicular direction, and the transport of the printing paper P.

[0024] As shown in Figure 2, a unit in which multiple (for example, eight) liquid discharge heads 1 are arranged on a single frame 106 is also called a Line Head Unit (LHU). Figure 2 shows an example of a Line Head Unit 1A in which four liquid discharge heads 1 are positioned in a staggered pattern in front of the printing paper P in the transport direction and four in the rear. In the Line Head Unit 1A, the multiple liquid discharge heads 1 are positioned such that the centers of each liquid discharge head 1 do not overlap in the transport direction of the printing paper P.

[0025] The four line head units 1A are positioned along the transport direction of the printing paper P. The liquid ejection heads 1 belonging to the same line head unit 1A are supplied with ink of the same color. As a result, the printer 100 can perform printing with four colors of ink using the four line head units 1A. The four line head units 1A may be arranged adjacent to each other to form a carriage, which is one example of the final form of the liquid ejection head 1.

[0026] The ink colors ejected from each line head unit 1A are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 200 controls each line head unit 1A to eject multiple colors of ink onto the printing paper P, thereby enabling the printing of a color image on the paper P.

[0027] Furthermore, in order to treat the surface of the printing paper P, a coating agent may be dispensed onto the printing paper P from the liquid discharge head 1.

[0028] Furthermore, the number of liquid ejection heads 1 included in one line head unit 1A, or the number of line head units 1A installed in the printer 100, can be appropriately changed depending on the object to be printed or the printing conditions. For example, if the color to be printed on the printing paper P is a single color and the printing is limited to the area that can be printed with one liquid ejection head 1, then the number of liquid ejection heads 1 installed in the printer 100 may be as small as one.

[0029] The printed paper P, which has been processed inside the head case 105, is transported to the outside of the head case 105 by the transport roller 103, then transported by the guide roller 102B, and passes through the inside of the dryer 107. The dryer 107 dries the printed paper P. The printed paper P that has been dried in the dryer 107 is transported by the guide roller 102C and collected by the recovery roller 104.

[0030] In the printer 100, drying the printing paper P in the dryer 107 reduces the likelihood of the overlapping printing paper P sticking together or of undried liquid rubbing against each other in the recovery roller 104.

[0031] The sensor unit 108 is composed of a position sensor, a speed sensor, or a temperature sensor, etc. Based on the information from the sensor unit 108, the control unit 200 can determine the state of each part of the printer 100 and control each part of the printer 100.

[0032] The printer 100 described so far has shown the case where printing paper P is used as the printing target (i.e., recording medium), but the printing target in the printer 100 is not limited to printing paper P. For example, the printing target may be a roll of cloth or the like.

[0033] Alternatively, the printer 100 may transport the printing paper P on a conveyor belt instead of directly transporting it. By using a conveyor belt, the printer 100 can print on sheets of paper, cut cloth, wood, tiles, etc.

[0034] The printer 100 may also print wiring patterns for electronic devices by ejecting droplets containing conductive particles from the liquid ejection head 1. Alternatively, the printer 100 may produce chemical products by ejecting a predetermined amount of liquid chemical agent or droplets containing a chemical agent from the liquid ejection head 1 toward a reaction vessel or the like.

[0035] The printer 100 may also include a cleaning unit for cleaning the liquid ejection head 1. The cleaning unit cleans the liquid ejection head 1, for example, by wiping or capping.

[0036] Wiping is a process that removes liquid adhering to the liquid discharge head 1 by wiping the surface of the area where the liquid droplets are discharged with a flexible wiper, for example.

[0037] Furthermore, the capping process is carried out, for example, as follows: First, a cap is placed over the surface of the area from which the droplets are dispensed (this is called capping). This creates a nearly sealed space between the surface of the area from which the droplets are dispensed and the cap.

[0038] Next, the ejection of droplets is repeated in such a sealed space. This can remove liquids or foreign substances that are more viscous than the standard state and are clogging the ejection holes (nozzles) for ejecting the droplets.

[0039] <Configuration of the liquid ejection head in the line head unit> Next, the configurations of the liquid ejection head 1 and the line head unit 1A according to an embodiment will be described with reference to FIGS. 3 to 6. FIG. 3 is an exploded perspective view showing the schematic configuration of the liquid ejection head 1 step by step. FIG. 4 is an exploded perspective view showing the schematic configuration of the line head unit 1A step by step. FIG. 5 is a cross-sectional view taken along the line A-A shown in FIG. 3. FIG. 6 is a perspective view showing a partial schematic configuration within the MEMS chip 10.

[0040] The liquid ejection head 1 is assembled in the order of FIGS. 3(a) to 3(c). The line head unit 1A is assembled in the order of FIGS. 4(a) and 4(b) using eight liquid ejection heads 1 shown in FIG. 3(c). As shown in FIG. 3(a), the liquid ejection head 1 has a MEMS (Micro Electro Mechanical Systems) chip 10 and a COF substrate (Chip on Film) 11 on a film. One end of the MEMS chip 10 is adhered to one end of the COF substrate 11. Thereby, as shown in FIG. 3(b), the terminal 143 (see FIG. 5) arranged at one end of the MEMS chip 10 and the wiring (not shown) within the COF substrate 11 are connected, and thus the MEMS chip 10 is electrically connected to the COF substrate 11. Note that the MEMS chip 10 can also be referred to as a ejection chip or an individual flow path member.

[0041] The COF substrate 11 mounts a drive IC 111. The drive IC 111 can communicate with the control unit 200 wirelessly or by wire. Therefore, the drive IC 111 generates a drive signal based on the control signal transmitted from the control unit 200. Then, the drive IC 111 outputs the drive signal to an actuator substrate 3, which will be described later, within the MEMS chip 10 via the COF substrate 11. Thereby, the drive IC 111 can control the drive of the liquid ejection head 1.

[0042] Furthermore, as shown in Figure 3(b), the liquid discharge head 1 has a manifold member 12. The manifold member 12 has a common flow path 123 inside.

[0043] The manifold member 12 may have a layered structure of multiple plates, or it may be a single plate. Each plate has a base portion 12a and a projection portion 12b. The projection portion 12b is the part that protrudes from the central region when the base portion 12a is divided into three parts in the longitudinal direction. The longitudinal direction of the base portion 12a is longer than the longitudinal direction of the MEMS chip 10. The manifold member 12 is joined to the MEMS chip 10 such that the base portion 12a is positioned on top of the MEMS chip 10. This constitutes an ultra-compact integrated module called a so-called front-end module (FEM), as shown in Figure 3(c).

[0044] As an example of the layered structure of the manifold member 12, referring to Figure 5, which shows a cross-section along line A-A in Figure 3(c), the manifold member 12 has a structure in which the top layer plate 121a, the middle layer plate 121b, and the bottom layer plate 121c are stacked from top to bottom. The top layer plate 121a has a filter 121f. The upper part of the filter 121f is connected to the reservoir flow path of the reservoir member 14 (see Figure 4(b)). The filter 121f is located at the protruding portion 12b and filters out impurities from the liquid in the reservoir flow path. The top layer plate 121a has a flow path 121 through which the filtered liquid flows. The bottom layer plate 121c has a common flow path 123 along the longitudinal direction of the base portion 12a. The intermediate plate 121b is located between the uppermost plate 121a and the lowermost plate 121c, and has a hole 122 that connects the flow path 121 of the uppermost plate 121a with the common flow path 123.

[0045] As shown in Figure 4(a), eight front-end modules (FEMs) are arranged in a staggered pattern, and eight manifold members 12 are joined together in a line. This positions eight common flow paths 123 above the eight MEMS chips 10. Also, as shown in Figure 4(b), a nozzle cover 13 is joined below the eight MEMS chips 10, covering the eight MEMS chips 10. This covers and protects the eight MEMS chips 10. The longitudinal length of the nozzle cover 13 is longer than the length of the eight manifold members 12. The nozzle cover 13 has eight rectangular openings 133. The openings 133 are positioned to correspond to the eight nozzles 41 (see Figure 5) of the eight MEMS chips 10, allowing liquid to be discharged from the eight nozzles 41.

[0046] Furthermore, the line head unit 1A has a reservoir member 14 with a reservoir channel (not shown) inside. The longitudinal direction of the reservoir member 14 is longer than the length of the eight manifold members 12 on the line and is approximately equal to the length of the nozzle cover 13. The reservoir member 14 is joined to the eight manifold members 12 so as to be located above the eight manifold members 12. As a result, the reservoir channel is located on the eight common channels 123 of the eight manifold members 12.

[0047] The reservoir member 14 is an injection-molded product made of resin. Here, "made of resin" means that it is made of resin, and includes products that are mainly composed of resin and contain small amounts of impurities. The reservoir member 14 supplies liquid by dividing it from the reservoir channel to eight common channels 123.

[0048] Liquid supply ports 15 and liquid discharge ports 16 are located at both ends of the reservoir member 14 in the Y-axis direction. Liquid is supplied from the liquid supply ports 15 to the reservoir flow path within the reservoir member 14. The liquid discharge head 1 temporarily stores the liquid supplied to the reservoir member 14 in the reservoir flow path, supplies it to eight common flow paths 123 that branch off from the reservoir flow path, and discharges it from the nozzle 41 through individual flow paths within the MEMS chip 10 located below each common flow path 123. The liquid discharge head 1 discharges any liquid that was not supplied from the reservoir flow path of the reservoir member 14 to each common flow path 123 from the liquid discharge ports 16.

[0049] Furthermore, the liquid ejection head 1 may collect liquid from the liquid outlet 16 while printing is in progress. Doing so makes it less likely for air bubbles to accumulate in the reservoir flow path within the reservoir member 14. In addition, the temperature of the liquid ejection head 1 can be stabilized by supplying liquid adjusted to a constant temperature. The collected liquid may be passed through a filter or the like and then supplied back to the liquid ejection head 1. In other words, the liquid ejection head 1 may circulate the liquid. The supply and collection of liquid to and from the liquid ejection head 1, or the circulation of liquid, may be controlled by the control unit 200.

[0050] The above description shows an example of the configuration of the liquid discharge head 1, and the configuration in Figure 4(b) may further include a circuit board, a heat sink for dissipating heat generated from the circuit board, cover members for the circuit board and heat sink, etc. For convenience, descriptions of these components have been omitted.

[0051] <Channel Group> The thickness direction of the MEMS chip 10 is defined as the Z-axis direction, and the positive Z-axis direction is defined as the vertically upward direction. The longitudinal direction (Y-axis direction) of the MEMS chip 10 is also called the row direction, and the short direction (X-axis direction) of the MEMS chip 10 is also called the column direction. In the example in Figure 5, the MEMS chips 10 located on both sides of line O show cross-sections of two channels arranged symmetrically with respect to line O.

[0052] A channel refers to a single unit configuration that includes a flow path extending from the liquid chamber 131 to the nozzle 41 through a supply path 51 and a connecting passage 52 (hereinafter also referred to as the "vertical aperture 50") and a horizontal aperture 53, an actuator 30, and a diaphragm 38. A group of channels consisting of 100 to 2000 channels in the row direction and two channels arranged in the column direction is called a channel group 10a, 10b. Channel groups 10a, 10b are arranged symmetrically with respect to line O shown in Figure 5. However, the number of channel groups can be changed as appropriate.

[0053] The MEMS chip 10 has a substrate in which a support substrate 2, an actuator substrate 3, and a nozzle substrate 4 are stacked from top to bottom. However, the three substrates, the support substrate 2, the actuator substrate 3, and the nozzle substrate 4, may be integrated into a single unit. Alternatively, only the two substrates, the actuator substrate 3 and the nozzle substrate 4, may be integrated into a single unit.

[0054] The support substrate 2 has a supply passage 51. The actuator substrate 3 has a communication passage 52, an actuator 30, and a diaphragm 38. The diaphragm 38 is positioned on the lower surface of the actuator 30. The area around the actuator 30 is covered by a space 132, except for the lower surface. Furthermore, the actuator substrate 3 has a lateral aperture 53 and a liquid chamber 131. The nozzle substrate 4 has nozzles 41 for discharging liquid. The liquid chambers 131 are arranged in rows of 100 to 2000 units and in columns of 2 units, for a total of 200 to 4000 units. Corresponding to the liquid chambers 131, there are 100 to 2000 nozzles 41 in the row direction and in columns of 2 units, for a total of 200 to 4000 nozzles 41, along with the same number of vertical apertures 50 and horizontal apertures 53 as there are nozzles 41. The flow path P2 (see Figure 7), which is composed of the vertical apertures 50, horizontal apertures 53, liquid chambers 131, and nozzles 41, is an individual flow path. In this configuration, the channel groups 10a and 10b according to this embodiment have individual channels (channels P2) arranged in two rows of 100 to 2000 channels each along the row direction. The common channel 123 is a channel P1 common to 200 to 4000 channels, and is connected to 200 to 4000 vertical apertures 50 arranged in two rows of 100 to 2000 channels each, supplying liquid to the 200 to 4000 vertical apertures 50. In the plan view of a part of the actuator substrate 3 shown in Figure 9, parts of the channel groups 10a and 10b arranged in two rows along the row direction are shown within the dashed-dotted lines.

[0055] The bottom plate 121c is located on the support substrate 2. The upper surface of the support substrate 2 forms the bottom of the common channel 123. However, the bottom plate 121c may have a bottom and the common channel 123 may be located inside it. In this case, a hole communicating with the supply channel 51 may be provided in the bottom of the bottom plate 121c. The supply channel 51 penetrates the support substrate 2 in the Z-axis direction.

[0056] Figure 6 is a perspective view showing a schematic configuration of a part of channel group 10a, with channel group 10b omitted. As shown in Figure 6, the actuator substrate 3 can be electrically connected to the outside through terminal 143 by electrical junctions 141 and 142 located at one end of channel group 10a. One end of channel group 10a is located on the opposite side of channel group 10b.

[0057] <Configuration of Actuator Substrate> The detailed configuration of the actuator substrate 3 will be described with reference to Figures 7 to 9. Figure 7 is a cross-sectional view showing the detailed configuration of the actuator substrate 3. Figure 8 is a diagram showing an example of a cross-sectional view along the line B-B shown in Figure 7. Figure 9 is a schematic plan view showing a part of the actuator substrate 3. Note that Figure 7 shows the configuration of channel group 10a, and the configuration of channel group 10b is omitted. Since the configuration of channel group 10a and the configuration of channel group 10b are the same, the explanation of the configuration of channel group 10b is omitted. Also, for convenience, in Figure 7 the thickness of the actuator substrate 3 is shown to be thicker than the thickness of the support substrate 2 and nozzle substrate 4, but in reality the thickness of the support substrate 2 and nozzle substrate 4 may be thicker than the thickness of the actuator substrate 3.

[0058] The thickness (length in the Z-axis direction) of the support substrate 2 is, for example, 200 to 400 μm. The thickness (length in the Z-axis direction) of the actuator substrate 3 is, for example, 30 to 75 μm. The thickness (length in the Z-axis direction) of the nozzle substrate 4 is, for example, 75 to 150 μm. The constituent materials of the support substrate 2, actuator substrate 3 (excluding the bonding layer 31), and nozzle substrate 4 may be Si. Figure 7 shows an example of a first substrate in which the actuator substrate 3 has a transverse aperture 53. The support substrate 2 is an example of a second substrate in which the support substrate 2 has a longitudinal aperture 50. The nozzle substrate 4 is an example of a third substrate in which the nozzle 41 has a nozzle.

[0059] Furthermore, the support substrate 2, actuator substrate 3, and nozzle substrate 4 form an individual flow path member having a flow path P2 from the common flow path 123 to the nozzle 41. In this embodiment, the liquid discharge head 1 may have a manifold member 12 made of metal or resin. By constructing the manifold member 12 from metal or resin, manufacturing costs can be reduced compared to constructing the manifold member 12 from Si.

[0060] Furthermore, in this embodiment, since the manifold member 12 is located above the MEMS chip 10, in a plan view, the common flow path 123 can overlap with multiple nozzles 41 and multiple liquid chambers 131, thereby increasing the degree of freedom in manufacturing.

[0061] The actuator substrate 3 has a bonding layer 31. The bonding layer 31 bonds the actuator substrate 3 and the support substrate 2. The thickness of the bonding layer 31 may be several μm to 20 μm. The liquid chamber 131 is a space with a wider width in the Y-axis direction than the transverse aperture 53, and therefore has weaker strength (see Figure 10). Therefore, if the bonding layer 31 is located above the liquid chamber 131, the actuator substrate 3 is easily damaged. In contrast, the bonding layer 31 according to this embodiment is located above the transverse aperture 53. This reduces damage to the actuator substrate 3 compared to when the bonding layer 31 is located above the liquid chamber 131.

[0062] The bonding layer 31 is SiO ２ This may be the case. The bonding layer 31 is connected to the connecting passage 52 of the longitudinal aperture 50. That is, the connecting passage 52 penetrates the bonding layer 31, and the side surface of the connecting passage 52 is the SiO of the bonding layer 31. ２ The actuator substrate 3 and nozzle substrate 4 are formed from the same material, making them easy to join. For this reason, the joining of the actuator substrate 3 and nozzle substrate 4 by the joining layer 31 may be done by direct bonding at room temperature, or other joining methods such as adhesives or gold-gold bonding may be used.

[0063] Each channel's liquid chamber 131 corresponds one-to-one with the actuator 30, forming a single hollow region 3A within the actuator substrate 3. Liquid is stored in the liquid chamber 131. Each channel's liquid chamber 131 corresponds one-to-one with the supply passage 51, the communication passage 52, and the nozzle 41, and liquid is supplied from the common flow path 123 of the manifold member 12. In this embodiment, one common flow path 123 (flow path P1) supplies liquid to 200 to 4000 individual flow paths (flow paths P2) of channels.

[0064] For example, the depth (length in the Z-axis direction) of the supply passage 51 is equal to the thickness of the support substrate 2 and may be 200 to 400 μm. The depth (length in the Z-axis direction) of the communication passage 52 is equal to the length from the upper surface of the bonding layer 31 to the lower surface of the diaphragm 38 and may be several μm to 20 μm. The depth (length in the Z-axis direction) of the liquid chamber 131 may be a value obtained by subtracting the depth of the communication passage 52 from 30 to 75 μm.

[0065] The solid core 39 is located around each hollow region 3A between the diaphragm 38 and the nozzle substrate 4, and has the function of separating each hollow region 3A from other hollow regions 3A. Examples of materials that make up the solid core 39 include silicon.

[0066] The diaphragm 38 is provided on the liquid chamber 131 and on the solid 39. The diaphragm 38 has openings in parts corresponding to each liquid chamber 131. Liquid is supplied to the liquid chamber 131 from the common channel 123 through these openings. The openings in the diaphragm 38 constitute part of the vertical aperture 50.

[0067] The thickness of the diaphragm 38 may be, for example, 1 μm or more and 10 μm or less. The diaphragm 38 in this embodiment is a single layer, but is not limited to this. For example, the diaphragm 38 may have a multilayer structure. Also, the diaphragm 38 may have a multilayer structure locally, for example, only on the solid 39. That is, the thickness of the diaphragm 38 on the solid 39 may be thicker than the thickness of the diaphragm 38 on the liquid chamber 131. Examples of constituent materials for the diaphragm 38 are Si, SiO ２ These are some examples.

[0068] The actuator 30 is provided on a diaphragm 38 corresponding to the liquid chamber 131. The actuator 30 has a common electrode 35, a piezoelectric element 36, and individual electrodes 37. The actuator 30 is provided in a one-to-one relationship with the liquid chamber 131. The actuator 30 has the common electrode 35 located on the diaphragm 38 corresponding to the liquid chamber 131, the piezoelectric element 36 located on the common electrode 35, and the individual electrodes 37 located on the piezoelectric element 36, but is not limited to this configuration. For example, the individual electrodes 37, piezoelectric element 36, and common electrode 35 may be provided on the diaphragm 38 in that order.

[0069] In the plan view of the actuator substrate 3 shown in Figure 9, the common electrode 35 is provided across the actuators 30 of multiple channels in each channel group 10a, 10b, but is not limited to this. For example, the common electrode 35 may be provided individually corresponding to each actuator 30 of each channel. The thickness of the common electrode 35 may be, for example, 0.1 to 1 μm. The constituent material of the common electrode 35 may be, for example, a metallic material such as Pt.

[0070] The piezoelectric elements 36 are individually provided corresponding to each liquid chamber 131, but are not limited to this arrangement. For example, the piezoelectric elements 36 may be provided across multiple channels of liquid chambers 131 in a plan view of the actuator substrate 3. In the piezoelectric element 36, the portion sandwiched between the individual electrodes 37 and the common electrode 35 is polarized in the thickness direction along the Z-axis. Therefore, for example, when a voltage is applied in the polarization direction of the piezoelectric element 36 by the individual electrodes 37 and the common electrode 35, the piezoelectric element 36 contracts in the direction along the diaphragm 38. This contraction causes the piezoelectric element 36 to displace so that it becomes convex toward the liquid chamber 131. Along with the displacement of the piezoelectric element 36, the diaphragm 38 located on the liquid chamber 131 also displaces. As a result, pressure is applied to the liquid in the liquid chamber 131. This causes the liquid to be discharged from the liquid chamber 131 through the nozzle 41.

[0071] The thickness of the piezoelectric element 36 may be 1 μm or more and 10 μm or less. The constituent material of the piezoelectric element 36 is, for example, Pb(Zr,Ti)O ３ System, NaNbo ３ system, BaTiO ３ System, (BiNa)NboO ３ System, BiNaNB５ O １５ Examples of the ceramic constituent material having ferroelectricity include systems such as this.

[0072] The individual electrodes 37 are provided individually corresponding to each liquid chamber 131. The thickness of the individual electrode 37 may be 0.05 μm or more and 1 μm or less. Examples of the constituent material of the individual electrode 37 include metal constituent materials such as Pt.

[0073] The electrical joints 141 and 142 shown in FIGS. 6 and 9 are connected to a plurality of terminals 143 located on the end portion in the X-axis direction on the actuator substrate 3. The plurality of terminals 143 are electrically connected to the actuator substrate 3.

[0074] The bonding layer 31 is located under the support substrate 2, and its thickness may be, for example, several μm to 20 μm. Examples of the constituent material of the bonding layer 31 include materials such as SiO ２ and the like.

[0075] In addition to FIG. 7, referring to FIG. 8 showing a cross section along the line B - B shown in FIG. 7, under the bonding layer 31, a protective layer 32, an insulating layer 33, an adhesion layer 34, and a common electrode 35 are laminated in order from above. The thickness of the protective layer 32 may be, for example, 0.1 to 1 μm. Examples of the constituent material of the protective layer 32 include materials such as SiN.

[0076] The thickness of the insulating layer 33 may be, for example, 0.1 to 1 μm. Examples of the constituent material of the insulating layer 33 include materials such as SiO ２ and the like. The thickness of the adhesion layer 34 may be, for example, 0.01 to 0.1 μm. Examples of the constituent material of the adhesion layer 34 include materials such as SiN.

[0077] Note that an adhesion layer (not shown) may be provided between the common electrode 35 and the piezoelectric body 36 or between the piezoelectric body 36 and the individual electrode 37.

[0078] The lead wires 144 are electrically connected to the individual electrodes 37 and are wires that extend from each individual electrode 37 (see Figure 9). In the example in Figure 7, the lead wires 144 are positioned between the protective layer 32 and the insulating layer 33 and extend from the portion corresponding to the liquid chamber 131 to the portion corresponding to the solid 39. The thickness of the lead wires 144 may be, for example, 0.1 μm or more and 1 μm or less. The constituent material of the lead wires 144 may be, for example, Au.

[0079] The protective layer 32 protects the actuator 30 beneath the bonding layer 31. The insulating layer 33 is provided on the actuator 30 to prevent short circuits between the actuator 30 of each channel and the actuator 30 of other channels, or between wiring such as the lead wires 144. The insulating layer 33 is also provided on the diaphragm 38 to cover the lead wires 144 in order to reduce the possibility of corrosion of the lead wires 144. The insulating layer 33 is in close contact with the diaphragm 38, which generally corresponds to the solid 39 excluding the liquid chamber 131. As shown in Figure 8, the contact layer 34 is provided between the common electrode 35 and the insulating layer 33.

[0080] The bonding layer 31, protective layer 32, insulating layer 33, adhesion layer 34, common electrode 35, individual electrode 37, and lead wiring 144 according to this embodiment may be formed on each layer using the CVD method. By using the CVD method, the step coverage is improved, so the coverage of each layer and lead wiring 144 is improved, and the possibility of corrosion of each layer and lead wiring 144 can be further reduced. However, each layer and lead wiring 144 according to this embodiment may be formed using the sputtering method, not limited to the CVD method. By using the sputtering method, particles that will become the constituent material of each layer and lead wiring 144 will adhere to the surface. Therefore, the adhesion between each layer and the diaphragm 38 and lead wiring 144 can be improved.

[0081] The supply passage 51 and connecting passage 52 of the vertical aperture 50 are flow paths with a circular, elliptical, or other shape in cross-section. As shown in Figure 8, the maximum width L1 of the supply passage 51 is, for example, 45 to 49 μm, and the maximum width L2 of the connecting passage 52 is, for example, 35 to 45 μm. L1 may be larger than L2. This allows the liquid discharge head 1 to reduce the possibility of bubbles remaining at the connection T between the support substrate 2 and the actuator substrate 3, thereby improving bubble discharge performance.

[0082] The insulating layer 33 and the common electrode 35 are penetrated by the communication passage 52, which is located inside the insulating layer 33 and the common electrode 35. As shown in Figure 8, the maximum width L4 (diameter) in the Y-axis direction of the opening 33h of the insulating layer 33, which is located on the outer periphery side of the side of the communication passage 52, is, for example, 49 to 55 μm. Also, the maximum width L5 (diameter) in the Y-axis direction of the opening 35h of the common electrode 35, which is located on the outer periphery side of the opening 33h of the insulating layer 33, is, for example, 55 to 65 μm. L5 may be larger than L4.

[0083] Furthermore, as shown in Figure 7, the actuator 30 has a portion where the bonding layer 31 and insulating layer 33 are not located. The portion of the actuator 30 where the bonding layer 31 and insulating layer 33 are not located is exposed to the space 132. As a result, the liquid discharge head 1 can improve the displacement of the actuator 30 and improve the liquid discharge performance from the nozzle 41. Note that the liquid discharge head 1 forms a portion where the bonding layer 31 and insulating layer 33 are not located above the actuator 30 by etching until the actuator 30 is exposed.

[0084] The wiring of the actuator substrate 3 according to this embodiment will be further described with reference to Figure 9. In a plan view, the actuator substrate 3 shown in Figure 9 shows a portion of the channel groups 10a and 10b arranged in two rows. In reality, 100 to 2000 lead wires 144 are drawn out from the individual electrodes 37 of each channel in the channel groups 10a and 10b, each having 100 to 2000 individual flow paths (flow paths P2).

[0085] The number of lead wires 144 on each channel group 10a, 10b may be set as appropriate. Each lead wire 144, when viewed from above, is connected to an individual electrode 37 corresponding to the liquid chamber 131 and is led out in the positive X-axis direction. The lead wire 144 led out from channel group 10b is connected to an electrical junction 142. The electrical junction 142 runs in the positive X-axis direction within the region of channel group 10a and is electrically connected to the terminal 143 of the individual terminal region 201. The lead wire 144 led out from channel group 10a is connected to an electrical junction 141. The electrical junction 141 is electrically connected to the terminal 143 of the individual terminal region 201.

[0086] Therefore, each actuator 30 in channel groups 10a and 10b receives a drive signal from the drive IC 111 on the COF substrate 11 through the electrical junctions 141 and 142 and the terminal 143. Based on the drive signal, each actuator 30 applies an individual drive potential to the individual electrode 37 via the lead wiring 144 (see Figure 5).

[0087] With this configuration, each actuator 30 of channel groups 10a and 10b receives a drive signal corresponding to a desired control signal from the control unit 200 (Figure 9(1)), and displaces the piezoelectric element 36 so that it protrudes toward the liquid chamber 131 according to the drive signal. As the piezoelectric element 36 is displaced, the diaphragm 38 located on the liquid chamber 131 is displaced, and pressure is applied to the liquid in the liquid chamber 131. As a result, liquid is discharged from each liquid chamber 131 through each nozzle 41. This causes the drive IC 111 to drive the liquid discharge head 1.

[0088] The common electrode 35 is electrically connected to the ground connection 145 of the ground region 202 via a common wiring 146 (Figure 9(2)). As a result, the common electrode 35 is supplied with ground potential. Ground potential means 0V. Note that the common wiring 146 is not shown in Figures 5 to 7.

[0089] <Configuration of vertical aperture, horizontal aperture and liquid chamber> <First embodiment> Next, the configuration of the vertical aperture 50, horizontal aperture 53 and liquid chamber 131 will be described with reference to Figures 7, 10 and 11. Figure 10 is a cross-sectional view of the support substrate 2, actuator substrate 3, and nozzle substrate 4 of the liquid discharge head 1 according to the first embodiment, and a plan view of the support substrate 2. Figure 11 is a diagram showing an example of the dimensions of each part shown in Figure 10.

[0090] The liquid discharge head 1 according to this embodiment has two apertures: a vertical aperture 50 and a horizontal aperture 53. The vertical aperture 50 is connected to and located above the horizontal aperture 53. The horizontal aperture 53 is below the vertical aperture 50 and connected to the vertical aperture 50 and the liquid chamber 131 in the lateral direction of the liquid chamber 131. The horizontal aperture 53 is an example of a first aperture that is connected to the liquid chamber 131 in the lateral direction of the liquid chamber 131. The vertical aperture 50 is an example of a second aperture that is connected to and located above the first aperture.

[0091] The cross-sectional area of ​​the first aperture is smaller than the cross-sectional area of ​​the liquid chamber 131, and the cross-sectional area of ​​the second aperture is smaller than the cross-sectional area of ​​the liquid chamber 131. This relationship between the magnitudes of the cross-sectional areas is determined by one of the following: (1-1) the average value of the cross-sectional area obtained by dividing the volume by the length in the direction of the flow path; (1-2) the minimum value of the cross-sectional area; (1-3) the maximum value of the cross-sectional area.

[0092] For example, the cross-sectional area of ​​a horizontal aperture 53, which is an example of a first aperture, is the area of ​​the flow channel cross-section obtained by cutting the horizontal aperture 53 in a direction perpendicular to the longitudinal direction of the horizontal aperture 53. Also, for example, the cross-sectional area of ​​a vertical aperture 50, which is an example of a second aperture, is the area of ​​the flow channel cross-section obtained by cutting the vertical aperture 50 in a direction perpendicular to the longitudinal direction of the vertical aperture 50. Also, for example, the cross-sectional area of ​​a liquid chamber 131 is the area of ​​the flow channel cross-section obtained by cutting the liquid chamber 131 in a direction perpendicular to the longitudinal direction of the liquid chamber 131.

[0093] In addition to the relationship between the cross-sectional areas described above, the relationship between the flow path widths is also such that the flow path width of the first aperture may be smaller than the flow path width of the liquid chamber 131, and the flow path width of the second aperture may be smaller than the flow path width of the liquid chamber 131. This relationship between the flow path widths is determined by the flow path widths shown in any of (2-1) to (2-3). The flow path width is defined as the width direction in the shorter direction of the cross-sectional area described above. The flow path width may also be defined as the Z-axis direction when the flow path direction is the X-axis direction. The flow path width of the first aperture may be, for example, the diameter. (2-1) The magnitude of the average flow path width (2-2) The magnitude of the minimum flow path width (2-3) The magnitude of the maximum flow path width

[0094] For example, the flow path width of a horizontal aperture 53, which is an example of a first aperture, is the width in the short direction (Y-axis direction) of the flow path cross-section obtained by cutting the horizontal aperture 53 in a direction perpendicular to the longitudinal direction of the horizontal aperture 53. Also, for example, the flow path width of a vertical aperture 50, which is an example of a second aperture, is the width in the short direction of the flow path cross-section obtained by cutting the vertical aperture 50 in a direction perpendicular to the longitudinal direction of the vertical aperture 50. Here, since the flow path cross-section obtained by cutting the vertical aperture 50 in a direction perpendicular to the longitudinal direction of the vertical aperture 50 is circular, the diameter may be used as the flow path width. Also, for example, the flow path width of a liquid chamber 131 is the width in the short direction (Y-axis direction) of the flow path cross-section obtained by cutting the liquid chamber 131 in a direction perpendicular to the longitudinal direction of the liquid chamber 131.

[0095] When liquid is discharged from the nozzle 41, residual vibrations are generated in the flow paths of the vertical aperture 50 and the horizontal aperture 53 from the liquid chamber 131. If the next liquid is discharged from the nozzle 41 while residual vibrations remain, the residual vibrations interfere and affect droplet flight. In this embodiment, the liquid discharge head 1 has two apertures, a vertical aperture 50 and a horizontal aperture 53, where the cross-sectional area of ​​the horizontal aperture 53 is smaller than the cross-sectional area of ​​the liquid chamber 131, and the cross-sectional area of ​​the vertical aperture 50 is smaller than the cross-sectional area of ​​the liquid chamber 131. This configuration, in which the cross-sectional areas of the flow paths of the two apertures are smaller than the cross-sectional area of ​​the liquid chamber 131, increases the flow resistance and speeds up the damping rate of residual vibrations. As a result, the liquid discharge head 1 can increase the flow resistance and dampen the residual vibrations generated after liquid is discharged from the nozzle 41, thereby eliminating uneven liquid discharge and improving the printing performance of the liquid discharge head 1.

[0096] Furthermore, in the liquid discharge head 1, so-called crosstalk may occur, where pressure waves generated in the liquid chamber 131 connected to a certain individual flow path are transmitted to another individual flow path via the common flow path 123 due to the pressurization of the piezoelectric element 36. The piezoelectric element (piezoelectric element 36) is located above the liquid chamber 131. Due to the pressurization of the piezoelectric element, the pressure waves are transmitted toward the liquid chamber 131 and the plane of the lateral aperture 53 located beside the liquid chamber 131 that corresponds to the piezoelectric element. For this reason, if the vertical aperture 50 between the lateral aperture 53 and the common flow path 123 is located below the lateral aperture 53, the pressure waves are more likely to be transmitted directly from the lateral aperture 53 to the vertical aperture 50 and from the vertical aperture 50 to the common flow path 123. As a result, crosstalk is more likely to occur in a liquid discharge head with this configuration. Crosstalk can cause unexpected amounts of liquid to be dispensed from nozzles that are not intended for dispensing, or from nozzles that dispense a different amount of liquid than intended, potentially affecting printing performance.

[0097] In contrast, in the liquid discharge head 1 according to this embodiment, the vertical aperture 50 is located above the horizontal aperture 53, and the common flow path 123 is located above the vertical aperture 50. As a result, the pressure wave is less likely to be transmitted to the vertical aperture 50 and the common flow path 123, which are located above the horizontal aperture 53. Specifically, a piezoelectric element (piezoelectric body 36) is located above the liquid chamber 131, and due to the pressurization of the piezoelectric element, the pressure wave is transmitted towards the liquid chamber 131 and the bottom surface of the horizontal aperture 53 corresponding to the piezoelectric element. Since the vertical aperture 50 is located above the horizontal aperture 53, the pressure wave is not transmitted directly from the horizontal aperture 53 to the vertical aperture 50, but is first reflected off the bottom surface of the horizontal aperture 53, and the reflected pressure wave is then transmitted to the vertical aperture 50. Therefore, the apparent flow resistance from the horizontal aperture 53 to the vertical aperture 50 increases, making it difficult for pressure waves to propagate to the vertical aperture 50 and the common flow path 123 located above the vertical aperture 50. As a result, the liquid discharge head 1 according to this embodiment can reduce the occurrence of crosstalk.

[0098] In particular, as partially illustrated in Figure 9, two vertical apertures 50 (connecting passages 52) are located in close proximity in the column direction and 100 to 2000 vertical apertures 50 are located in the row direction, connected by a common flow path 123. As a result, crosstalk is likely to occur between the adjacent vertical apertures 50 of the channel groups 10a and 10b. Therefore, by having the above configuration, the liquid ejection head 1 makes it difficult for pressure waves to be transmitted to the vertical apertures 50 and the common flow path 123, thereby reducing the occurrence of crosstalk, which is important for improving the printing performance of the liquid ejection head 1 according to this embodiment.

[0099] Furthermore, if the common channel 123 is located below the vertical aperture 50, the nozzle 41 and the common channel 123 cannot be superimposed in a plan view, and the common channel 123 will be formed laterally on the XY plane relative to the nozzle 41. This reduces the degree of freedom in the configuration of the common channel 123, hindering the miniaturization of the liquid discharge head and contributing to increased manufacturing costs.

[0100] In contrast, in the liquid discharge head 1 according to this embodiment, the common channel 123 is located above the vertical aperture 50. As a result, in a plan view, the common channel 123 can be configured to overlap with the multiple nozzles 41 and the multiple liquid chambers 131. By overlapping the multiple nozzles 41 and the multiple liquid chambers 131 with the common channel 123 in a plan view, the liquid discharge head 1 can form the common channel 123 up to directly above the nozzles 41, for example. In this way, the degree of freedom in configuring the common channel 123 is increased, so the liquid discharge head 1 can be miniaturized and its manufacturing cost can be reduced. Furthermore, as shown in Figure 10, the longitudinal direction of the vertical aperture 50 is the direction from the common channel 123 to the horizontal aperture 53, i.e., the Z-axis direction. As a result, the vertical aperture 50 can rectify the uneven flow velocity vectors of the liquid flowing from the common channel 123 to the horizontal aperture 53.

[0101] As shown in Figure 5, the manifold member 12 may have a damper chamber 125 on a part of the inner wall of the common flow path 123 via a damper film 124. The damper chamber 125 is designed to absorb pressure waves transmitted from each channel via the common flow path 123 and the damper film 124. As a result, when pressure waves that may cause crosstalk arrive from each channel, the damper film 124 and the damper chamber 125 absorb the pressure waves, thereby reducing the occurrence of crosstalk via the common flow path 123. In addition, the damper film 124 and the damper chamber 125 may overlap with the vertical aperture 50 in a plan view. By positioning the damper film 124 and the damper chamber 125 on the vertical aperture 50 in this way, crosstalk occurring in the individual flow paths via the common flow path 123 can be further reduced.

[0102] As shown in Figures 10(a) and (b), the lateral aperture 53 may have a first portion 53a and a second portion 53b. The first portion 53a is connected to the liquid chamber 131 in the lateral direction (X-axis direction). The second portion 53b is connected to the first portion 53a in the lateral direction and to the vertical aperture 50 in the vertical direction (Z-axis direction). The liquid chamber 131 is connected to the nozzle 41 near the end opposite to the side connected to the first portion 53a. The nozzle substrate 4 is located on the nozzle 41 and may have a substantially rectangular descender 42 that includes the entire nozzle 41 in a plan view. This makes the flow of liquid discharged from the nozzle 41 smoother, thereby improving bubble discharge. However, the liquid chamber 131 may be connected to the nozzle 41 without going through the descender 42.

[0103] A piezoelectric element (piezoelectric body 36) that pressurizes the liquid chamber 131 is located above the liquid chamber 131. A vertical aperture 50 is located above the second portion 53b of the horizontal aperture 53. The first portion 53a is a flow path connecting the second portion 53b and the liquid chamber 131. In the plan view of Figure 10(a), the width of the first portion 53a in the Y-axis direction is smaller than the width of the liquid chamber 131 in the Y-axis direction. Also, the cross-sectional area of ​​the first portion 53a is smaller than the cross-sectional area of ​​the liquid chamber 131. The cross-sectional area of ​​the horizontal aperture 53 is smaller than the cross-sectional area of ​​the liquid chamber 131.

[0104] The liquid ejection head 1 has a configuration in which the cross-sectional area of ​​the lateral aperture (first portion 53a) is smaller than the cross-sectional area of ​​the liquid chamber 131, thereby increasing the flow resistance and damping residual vibrations. As a result, the liquid ejection head 1 can eliminate uneven liquid ejection and improve the printing performance of the liquid ejection head 1.

[0105] In a plan view, the width of the first portion 53a in the Y-axis direction is smaller than the width of the second portion 53b in the Y-axis direction. Also, the cross-sectional area of ​​the first portion 53a is smaller than the cross-sectional area of ​​the second portion 53b. Therefore, the lateral aperture 53 can increase the flow velocity when liquid flows from the second portion 53b to the first portion 53a. As a result, the lateral aperture 53 can reduce the possibility of air bubbles remaining inside and improve air bubble discharge.

[0106] In the plan view of Figure 10(a), the side surface of the liquid chamber 131 has a portion where both sides are parallel along the X-axis direction, and a portion where one side is an inclined surface 131s1 with respect to the X-axis direction. A piezoelectric element (piezoelectric body 36) is located on the portion where both sides of the liquid chamber 131 are parallel. In the plan view, the other side of the portion where one side of the liquid chamber 131 is an inclined surface 131s1 is on the same straight line as the side surface of the liquid chamber 131 and is connected to the first portion 53a.

[0107] Furthermore, in the plan view of Figure 10(a), the second portion 53b has a portion where both sides are parallel along the X-axis direction and a portion where one side is an inclined surface 131s2 with respect to the X-axis direction. The vertical aperture 50 is located on the portion of the second portion 53b where both sides are parallel. In the plan view, the other side of the portion of the second portion 53b where one side is an inclined surface 131s2 is on the same straight line as the side of the liquid chamber 131 and the first portion 53a, and is connected to the first portion 53a. As a result, in the plan view, the first portion 53a and the second portion 53b are connected with one side inclined. Also, in the plan view, one of the sides of the second portion 53b is inclined, and the other is not.

[0108] By not providing a slope on one side of the liquid chamber 131, the first section 53a, and the second section 53b, the possibility of air bubbles remaining can be reduced. This allows the liquid discharge head 1 to improve the air bubble discharge performance when flowing liquid from the liquid chamber 131 to the nozzle 41. As a result, the liquid discharge head 1 can reduce deterioration of liquid discharge characteristics, for example. Furthermore, even if air bubbles remain, the liquid discharge head 1 can easily discharge the liquid from the lateral aperture 53 during purging, such as between prints or when the user returns due to a printing defect.

[0109] Furthermore, as shown in Figure 10(b), the height of the first portion 53a (length in the Z-axis direction), the height of the second portion 53b, and the height of the liquid chamber 131 may be the same. This allows the liquid discharge head 1 to improve the machining accuracy in the height direction during etching of the lateral aperture 53 and the liquid chamber 131.

[0110] The longitudinal length of the vertical aperture 50 may be longer than the longitudinal length of the horizontal aperture 53. The longitudinal direction of the vertical aperture 50 is the Z-axis direction, and the longitudinal direction of the horizontal aperture 53 is the X-axis direction. As shown in Figure 11, the longitudinal direction of the vertical aperture 50 is 200 to 400 μm or more, and the longitudinal direction of the horizontal aperture 53 is 150 to 200 μm.

[0111] The longer the flow path, the higher the flow resistance. Therefore, the flow resistance can be increased by increasing the length of at least one of the vertical aperture 50 or the horizontal aperture 53. By increasing the flow resistance, the liquid ejection head 1 can reduce residual vibrations that occur after ejecting liquid from the nozzle 41, thereby eliminating uneven liquid ejection and improving the printing performance of the liquid ejection head 1.

[0112] By making the longitudinal length of the vertical aperture 50 longer than the longitudinal length of the horizontal aperture 53, the size of the liquid discharge head 1 in the X-axis direction does not increase, thus allowing the liquid discharge head 1 to be miniaturized. This reduces the manufacturing cost of the liquid discharge head 1.

[0113] The length of the vertical aperture 50 in the thickness direction may be longer than the length of the horizontal aperture 53 in the thickness direction. By making the length of the horizontal aperture 53 in the thickness direction shorter than the length of the vertical aperture 50 in the thickness direction, the processing accuracy of the width of the horizontal aperture 53 can be increased when etching the horizontal aperture 53, and dimensional variations can be reduced.

[0114] A liquid chamber 131 is located in the lateral direction of the lateral aperture 53. Therefore, in order to improve the processing accuracy of the lateral aperture 53 and the liquid chamber 131 and reduce dimensional variations, the thickness of the actuator substrate 3 is made thin to within the range of 30 to 75 μm. As a result, the strength is reduced, so the support substrate 2 is made thick to within the range of 200 to 400 μm to ensure overall strength. By making the support substrate 2 thicker and making the length of the vertical aperture 50 in the thickness direction (Z direction) longer than the length of the lateral aperture 53 in the thickness direction (Z direction), the liquid discharge head 1 can increase its flow resistance. As a result, the liquid discharge head 1 can reduce residual vibrations that occur after the liquid is discharged from the nozzle 41, thereby eliminating unevenness in liquid discharge and improving the printing performance of the liquid discharge head 1.

[0115] Furthermore, the length of the actuator substrate 3 in the Z direction may be longer than the length of the bonding layer 31 in the Z direction. For example, the length of the actuator substrate 3 in the first direction is 30 μm or more, which is longer than the length of the bonding layer 31, which is several μm to 20 μm. This allows the liquid discharge head 1 to improve the strength of the actuator substrate 3 that receives the force of the piezoelectric element 36.

[0116] Furthermore, the bonding layer 31 may also constitute part of the vertical aperture 50. As shown in Figure 8, the side surface of the connecting passage 52 has the bonding layer 31, protective layer 32, and diaphragm 38 exposed in that order from top to bottom. Therefore, the bonding layer 31 is connected to the vertical aperture 50 (connecting passage 52). Rather than providing another layer on the side surface of the bonding layer 31 so that the bonding layer 31 is not connected to the vertical aperture 50, the manufacturing cost and time of the liquid discharge head 1 can be reduced by having the bonding layer 31 constitute part of the vertical aperture 50 and not providing another layer.

[0117] SiO ２The insulating material is impermeable to liquids such as ink. Therefore, the bonding layer 31 is made of SiO ２ By being constructed of insulating material, the liquid dispensing head 1 can reduce the possibility of contact between the piezoelectric element 36 and the liquid. As a result, the liquid dispensing head 1 can reduce the possibility of a short circuit in the piezoelectric element 36.

[0118] The vertical aperture 50, horizontal aperture 53, liquid chamber 131, descender 42, nozzle 41, and space 132 may be formed by etching.

[0119] The dimensions of each part shown in Figure 11 are noted below. For convenience, the actuator 30 and space 132 are omitted from the illustration in Figure 11. Z-axis length of support substrate 2: 200-400 μm Z-axis length of actuator substrate 3: 30-75 μm Z-axis length of nozzle substrate 4: 75-150 μm Z-axis length of liquid chamber 131: 30-75 μm X-axis length from liquid chamber 131 to lateral aperture 53: 650-1000 μm X-axis length of liquid chamber 131 (straight portion): 400-600 μm X-axis length of liquid chamber 131 (inclined portion): 50-100 μm X-axis length of first portion 53a: 150-200 μm X-axis length of second portion 53b (inclined portion): 10-30 μm X-axis length of second portion 53b (straight portion): 40-70 μm Y-axis width of liquid chamber 131 (maximum): 60-80 μm Y-axis width of first portion 53a: 10-30 μm Width in the Y-axis direction of the second part 53b (maximum value): 35-45 μm Inclination angle θ2 of the liquid chamber 131 (inclined portion): Approximately 20-40° Inclination angle θ1 of the second part 53b (inclined portion): Approximately 40-60° Diameter φ1 of the vertical aperture 50 (supply passage 51): 45-49 μm Diameter φ2 of the vertical aperture 50 (communication passage 52): 35-45 μm Diameter φ3 of the nozzle 41: 15-25 μm

[0120] In one embodiment, the recording device (for example, a printer 100) may include the liquid ejection head 1 of one embodiment and a control unit (for example, a control unit 200) that controls the liquid ejection head 1.

[0121] <Effects of one embodiment> For example, the liquid discharge head 1 according to one embodiment comprises a plurality of individual flow paths (e.g., flow path P2) and a common flow path 123 (e.g., flow path P1) connected to the plurality of individual flow paths. Each of the plurality of individual flow paths has a nozzle 41, a liquid chamber 131 located above the nozzle 41, a first aperture (e.g., a lateral aperture 53) connected to the liquid chamber 131 in the lateral direction of the liquid chamber 131, and a second aperture (e.g., a vertical aperture 50) connected to the first aperture and located above the first aperture. Each of the plurality of liquid chambers 131 has a plurality of actuators 30 located above it. The cross-sectional area of ​​the first aperture is smaller than the cross-sectional area of ​​the liquid chamber 131, and the cross-sectional area of ​​the second aperture is smaller than the cross-sectional area of ​​the liquid chamber 131.

[0122] A piezoelectric element (piezoelectric body 36) is located above the liquid chamber 131. Due to the pressurization of the piezoelectric element, pressure waves propagate toward the liquid chamber 131 and the surface of the first aperture located beside the liquid chamber 131 that corresponds to the piezoelectric element. Therefore, if the second aperture between the first aperture and the common flow path 123 is located below the first aperture, pressure waves are more likely to propagate directly from the first aperture to the second aperture and from the second aperture to the common flow path 123. As a result, crosstalk is more likely to occur in a liquid ejection head with this configuration. When crosstalk occurs, an unexpected amount of liquid may be ejected from a nozzle that is not intended for ejection, or an amount of liquid different from the original ejection amount may be ejected from the nozzle, which may affect printing performance.

[0123] In contrast, in the liquid ejection head 1 according to this embodiment, the second aperture is located above the first aperture. As a result, the pressure wave is less likely to be transmitted to the second aperture and the common flow path 123, which are located above the first aperture. Specifically, a piezoelectric element (piezoelectric body 36) is located above the liquid chamber 131, and due to the pressurization of the piezoelectric element, the pressure wave is transmitted from the liquid chamber 131 to the bottom surface of the first aperture corresponding to the piezoelectric element. Since the second aperture is located above the first aperture, the pressure wave is not transmitted directly from the first aperture to the second aperture, but bounces off the bottom surface of the first aperture, and the bounced pressure wave is transmitted to the second aperture. As a result, the apparent flow resistance from the first aperture to the second aperture is increased, and the pressure wave is less likely to be transmitted to the second aperture and the common flow path 123. Therefore, the liquid ejection head 1 according to this embodiment can reduce the occurrence of crosstalk and improve printing performance.

[0124] Furthermore, the cross-sectional area of ​​the first aperture is smaller than the cross-sectional area of ​​the liquid chamber 131, and the cross-sectional area of ​​the second aperture is smaller than the cross-sectional area of ​​the liquid chamber 131. As a result, the first and second apertures act as constrictions in the flow path from the liquid chamber 131 to the common flow path 123, thereby increasing the flow resistance. This allows the liquid ejection head 1 to increase the flow resistance and reduce residual vibrations that occur after the liquid is ejected from the nozzle 41, thereby eliminating uneven liquid ejection and improving the printing performance of the liquid ejection head 1.

[0125] In one embodiment, the cross-sectional area of ​​the second aperture is described as being smaller than the cross-sectional area of ​​the liquid chamber 131, but this is not limited to this. The cross-sectional area of ​​the second aperture may be the same as the cross-sectional area of ​​the liquid chamber 131, or larger than the cross-sectional area of ​​the liquid chamber 131. Furthermore, the cross-sectional area of ​​the second aperture may be larger than the cross-sectional area of ​​the first aperture.

[0126] <Second Embodiment> The liquid discharge head 1 according to the second embodiment will be described with reference to Figure 12. In the second embodiment, the components not mentioned may be the same as or different from those in the first embodiment described above.

[0127] Figure 12 shows a cross-sectional view of the support substrate 2, actuator substrate 3, and nozzle substrate 4 of the liquid discharge head 1 according to the second embodiment, and a plan view of the support substrate 2.

[0128] In the liquid discharge head 1 of the second embodiment, the cross-sectional area of ​​the second aperture is larger than the cross-sectional area of ​​the liquid chamber 131. For example, the cross-sectional area of ​​the supply passage 51 of the vertical aperture 50, which is an example of a second aperture, is larger than the cross-sectional area of ​​the liquid chamber 131.

[0129] As shown in Figure 12(a), when the support substrate 2 is viewed from the Z-axis direction, the supply path 51 has a shape with a longitudinal direction and a transverse direction. When viewed from the Z-axis direction, the longitudinal direction of the supply path 51 is the longitudinal direction of the actuator 30, i.e., the X-axis direction. In other words, the longitudinal direction of the supply path 51 when viewed from the Z-axis direction is aligned with the longitudinal direction of the actuator 30. This makes it possible to reduce the spacing between multiple adjacent supply paths 51 in the transverse direction of the actuator 30, i.e., the Y-axis direction, compared to the case where the longitudinal direction of the supply path 51 when viewed from the Z-axis direction is not aligned with the longitudinal direction of the actuator 30. Note that, when viewed from the Z-axis direction, the longitudinal direction of the supply path 51 is the longitudinal direction of the actuator 30, but this is not the only case. It is sufficient if the transverse direction of the supply path 51 intersects with the longitudinal direction of the actuator 30.

[0130] As shown in Figure 12(a), when viewed from the Z-axis direction, the supply path 51 is oval-shaped. An oval shape is the trajectory obtained by moving the center of a circle parallel to a line segment. An oval shape is composed of a part of a circle and a straight line. As shown in Figure 12(b), the opening width in the X-axis direction of the supply path 51 that opens into the support substrate 2 is larger than the opening width in the X-axis direction of the supply path 51 in the first embodiment shown in Figure 10(b). The longitudinal direction of the vertical aperture 50, which is an example of a second aperture, is the direction from the common flow path 123 toward the horizontal aperture 53, which is an example of a first aperture. In the second embodiment, it has been described that the supply path 51 is oval-shaped, but it is not limited to this. When viewed from the Z-axis direction, the supply path 51 may be rectangular, elliptical, or other shapes, with the longitudinal direction of the supply path 51 being the longitudinal direction of the actuator 30.

[0131] Furthermore, the following additional information is disclosed with respect to the above embodiments. <Additional Information> (1) A liquid discharge head comprising: a plurality of individual flow paths and a common flow path connected to the plurality of individual flow paths, wherein each of the plurality of individual flow paths comprises: a nozzle, a liquid chamber located above the nozzle, a first aperture connected to the liquid chamber in the lateral direction of the liquid chamber, and a second aperture connected to the first aperture and located above the first aperture, wherein actuators are located above each of the plurality of liquid chambers, and the cross-sectional area of ​​the first aperture is smaller than the cross-sectional area of ​​the liquid chamber. (2) The liquid discharge head according to (1), wherein the cross-sectional area of ​​the second aperture is larger than the cross-sectional area of ​​the liquid chamber. (3) The liquid discharge head according to (1), wherein the cross-sectional area of ​​the second aperture is larger than the cross-sectional area of ​​the first aperture. (4) The liquid discharge head according to (1), wherein the longitudinal direction of the second aperture is in the direction from the common flow path toward the first aperture. (5) The liquid discharge head according to (1), wherein the common flow path is located above a plurality of second apertures. (6) The liquid discharge head according to any one of (1) to (4), wherein the first aperture has a first portion connected to the liquid chamber and a second portion connected to the first portion and connected to the second aperture, and the cross-sectional area of ​​the first portion is smaller than the cross-sectional area of ​​the second portion. (7) The liquid discharge head according to (6), wherein in a plan view, the first portion and the second portion are connected with one side inclined. (8) The liquid discharge head according to (7), wherein in a plan view, one of the sides of the second portion is inclined and the other is not. (9) The liquid discharge head according to any one of (1) to (8), wherein the longitudinal length of the second aperture is longer than the longitudinal length of the first aperture. (10) The liquid discharge head according to any one of (1) to (9), wherein the thickness-direction length of the second aperture is longer than the thickness-direction length of the first aperture. (11) The liquid discharge head according to any one of (1) to (10), wherein in a plan view, the common flow path overlaps the plurality of nozzles and the plurality of liquid chambers.(12) A liquid discharge head according to any one of (1) to (11), comprising a first substrate having the first aperture and a second substrate having the second aperture, wherein the first substrate has a bonding layer on the first aperture that bonds the first substrate and the second substrate. (13) A liquid discharge head according to (12), wherein the bonding layer constitutes a part of the second aperture. (14) A liquid discharge head according to (12) or (13), comprising a third substrate having the nozzle, wherein the three substrates of the first substrate, the second substrate and the third substrate constitute an individual flow path member having a flow path from the common flow path to the nozzle. (15) A recording device comprising a liquid discharge head according to any one of (1) to (14) and a control unit for controlling the liquid discharge head.

[0132] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0133] 1 Liquid discharge head 2 Support substrate 3 Actuator substrate 4 Nozzle substrate 10 MEMS chip 10a, 10b Channel group 12 Manifold member 30 Actuator 31 Bonding layer 32 Protective layer 33 Insulating layer 34 Adhesion layer 35 Common electrode 36 Piezoelectric element 37 Individual electrode 38 Diaphragm 41 Nozzle 50 Vertical aperture 51 Supply path 52 Connecting passage 53 Horizontal aperture 100 Printer 123 Common flow path 131 Liquid chamber 200 Control unit

Claims

1. A liquid discharge head comprising a plurality of individual flow paths and a common flow path connected to the plurality of individual flow paths, wherein each of the plurality of individual flow paths comprises a nozzle, a liquid chamber located above the nozzle, a first aperture connected to the liquid chamber in the lateral direction of the liquid chamber, and a second aperture connected to and located above the first aperture, wherein an actuator is located above each of the plurality of liquid chambers, and the cross-sectional area of ​​the first aperture is smaller than the cross-sectional area of ​​the liquid chamber.

2. The liquid discharge head according to claim 1, wherein the cross-sectional area of ​​the second aperture is greater than the cross-sectional area of ​​the liquid chamber.

3. The liquid dispensing head according to claim 1, wherein the cross-sectional area of ​​the second aperture is greater than the cross-sectional area of ​​the first aperture.

4. The liquid discharge head according to claim 1, wherein the longitudinal direction of the second aperture is in the direction from the common flow path toward the first aperture.

5. The liquid discharge head according to claim 1, wherein the common flow path is located above a plurality of the second apertures.

6. The liquid dispensing head according to any one of claims 1 to 4, wherein the first aperture has a first portion connected to the liquid chamber and a second portion connected to the first portion and also connected to the second aperture, and the cross-sectional area of ​​the first portion is smaller than the cross-sectional area of ​​the second portion.

7. The liquid dispensing head according to claim 6, wherein, in a plan view, the first portion and the second portion are connected by inclining one side.

8. The liquid dispensing head according to claim 7, wherein, in a plan view, one of the sides of the second portion is inclined and the other is not inclined.

9. The liquid dispensing head according to any one of claims 1 to 8, wherein the longitudinal length of the second aperture is longer than the longitudinal length of the first aperture.

10. The liquid dispensing head according to any one of claims 1 to 9, wherein the length of the second aperture in the thickness direction is longer than the length of the first aperture in the thickness direction.

11. In a plan view, the common flow path overlaps the plurality of nozzles and the plurality of liquid chambers, as described in any one of claims 1 to 10.

12. A liquid dispensing head according to any one of claims 1 to 11, comprising a first substrate having the first aperture and a second substrate having the second aperture, wherein the first substrate has a bonding layer on the first aperture that bonds the first substrate and the second substrate together.

13. The liquid dispensing head according to claim 12, wherein the bonding layer constitutes a part of the second aperture.

14. A liquid discharge head according to claim 12 or 13, comprising a third substrate having the nozzle, wherein the three substrates, the first substrate, the second substrate and the third substrate, constitute an individual flow path member having a flow path from the common flow path to the nozzle.

15. A recording device comprising: a liquid dispensing head according to any one of claims 1 to 14; and a control unit for controlling the liquid dispensing head.

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