Liquid discharge head

Abstract

To provide a liquid discharge head that is capable of retaining desired damper performance even when an environment around a liquid head varies.SOLUTION: A liquid discharge head includes a liquid discharge substrate which includes: a nozzle substrate having a plurality of nozzles to discharge liquid; a channel substrate having a plurality of pressure chambers that are in communication with the plurality of nozzles, respectively, a plurality of individual channels that are in communication with the plurality of pressure chambers, respectively, a plurality of pressure generating means for generating pressure in the plurality of pressure chambers, and a common channel that is in communication with the plurality of individual channels; and a damper substrate having a damper film disposed so as to face a surface opposite an opening surface of the channel in communication with the common channel, and a damper chamber covered with the damper film on one surface. The liquid discharge substrate includes atmosphere communication holes that allow communication of the damper chamber with atmosphere.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, and more particularly to a liquid ejection head having a damper structure. [Background technology]

[0002] This type of damper structure is composed of an elastically deformable damper membrane and a damper chamber containing air. This structure absorbs pressure fluctuations that occur in a common liquid chamber due to the ejection of liquid such as ink, reducing the effects of crosstalk between nozzles that accompany liquid ejection and pressure fluctuations caused by sudden changes in the print pattern. Patent Document 1 discloses a liquid ejection head in which the damper structure is disposed between a pressure chamber that applies pressure for liquid ejection and a layer of a flow path member that supplies liquid to the pressure chamber. This makes it possible to appropriately absorb pressure fluctuations that occur in the flow path of the flow path member due to liquid ejection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-155909 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration of Patent Document 1, the air inside the damper chamber is not connected to the outside. Therefore, for example, if the ambient temperature around the head changes, the pressure difference between the inside and outside of the damper chamber changes accordingly, affecting the behavior of the damper membrane when it deforms. Furthermore, if the ambient air pressure around the head changes, the pressure outside the damper chamber also changes, which similarly changes the pressure difference between the inside and outside of the damper chamber. As a result, the desired damper performance may not be achieved.

[0005] In view of the above-mentioned problems, an object of the present disclosure is to provide a liquid ejection head that is capable of maintaining desired damping performance even when the environment surrounding the liquid head changes. [Means for solving the problem]

[0006] A liquid ejection head having a liquid ejection substrate including: a nozzle substrate having a plurality of nozzles that eject liquid; a plurality of pressure chambers that communicate with the plurality of nozzles, each of which communicates with the plurality of pressure chambers; a plurality of pressure generating means that generate pressure in the plurality of pressure chambers, each of which communicates with the plurality of pressure chambers; and a common flow path that communicates with the plurality of individual flow paths; and a damper substrate having a damper membrane arranged so as to face a surface that faces the opening surface of the flow path that communicates with the common flow path, and a damper chamber that is covered on one side by the damper membrane, wherein the liquid ejection substrate is characterized by having an atmosphere communication hole that connects the inside of the damper chamber to the atmosphere. [Effects of the Invention]

[0007] The liquid ejection head of the present disclosure can maintain the desired damping performance even if the environment around the liquid head changes. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view of a liquid ejection device. [Figure 2] FIG. 2 is a perspective view of a liquid ejection head module. [Figure 3] FIG. 2 is a schematic diagram of a liquid ejection substrate. [Figure 4] 1A and 1B are a plan view and a cross-sectional view of a liquid ejection substrate of a liquid ejection head according to a first embodiment of the present disclosure. [Figure 5] FIG. 10 is a cross-sectional view of a liquid ejection substrate of a first modified example of the liquid ejection head according to the first embodiment of the present disclosure. [Figure 6] FIG. 10 is a cross-sectional view of a liquid ejection substrate of a second modified example of the liquid ejection head according to the first embodiment of the present disclosure. [Figure 7] 10A and 10B are a plan view and a cross-sectional view of a liquid ejection substrate of a liquid ejection head according to a second embodiment of the present disclosure. [Figure 8] 10A and 10B are a plan view and a cross-sectional view of a liquid ejection substrate of a liquid ejection head according to a third embodiment of the present disclosure. [Figure 9] FIG. 11 is a cross-sectional view of a liquid ejection substrate of a first modified example of a liquid ejection head according to a third embodiment of the present disclosure. [Figure 10] FIG. 11 is a cross-sectional view of a liquid ejection substrate of a second modified example of a liquid ejection head according to a third embodiment of the present disclosure. [Figure 11] 10A and 10B are a plan view and a cross-sectional view of a liquid ejection substrate of a liquid ejection head according to a fourth embodiment of the present disclosure. [Figure 12] FIG. 10 is a plan view of a liquid ejection substrate of a liquid ejection head according to a fifth embodiment of the present disclosure. [Figure 13] FIG. 13 is a plan view of a liquid ejection substrate of a liquid ejection head according to a sixth embodiment of the present disclosure. [Figure 14] 13A and 13B are a plan view and a cross-sectional view of a liquid ejection substrate of a liquid ejection head according to a seventh embodiment of the present disclosure. [Figure 15] 13A and 13B are a plan view and a cross-sectional view of a liquid ejection substrate of a liquid ejection head according to an eighth embodiment of the present disclosure. [Figure 16] FIG. 13 is a plan view of a liquid ejection substrate of a liquid ejection head according to a ninth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a liquid ejection head and a liquid ejection device according to an embodiment of the present invention will be described with reference to the drawings. In each of the following embodiments, an inkjet recording head and an inkjet liquid ejection device that eject ink will be described with specific configurations, but the present invention is not limited thereto. The liquid ejection head, liquid ejection device, and liquid supply method of the present invention can be applied to devices such as printers, copiers, facsimiles with communication systems, and word processors with printer units, as well as industrial recording devices combined with various processing devices. For example, they can also be used in applications such as biochip production and electronic circuit printing.

[0010] Furthermore, the embodiments described below are appropriate specific examples of the present invention, and therefore various technically preferable limitations are attached. However, as long as they are in line with the concept of the present invention, the present embodiments are not limited to the embodiments in this specification or other specific methods.

[0011] (First embodiment) (Description of Liquid Discharge Device) FIG. 1 is another schematic perspective view illustrating the general configuration of a liquid ejection device 101 according to an embodiment of a liquid ejection device to which the present disclosure can be applied.

[0012] The liquid ejection device 101 of this embodiment is a one-pass type that records an image on a recording medium 111 by moving the recording medium once, and the nozzles are arranged to cover the entire width of the recording medium 111. The liquid ejection device 101 is provided with a liquid ejection head module 1 of the present invention, for example, in a detachable manner.

[0013] A recording medium 111 is transported in the direction of arrow A by a transport unit 110, and printing is performed by a liquid ejection head module 1. Furthermore, for color printing, a liquid ejection head module 1 is used, which includes eight print heads 1Ca, 1Cb, 1Ma, 1Mb, 1Ya, 1Yb, 1Ka, and 1Kb that eject cyan (C), magenta (M), yellow (Y), and black (K) inks. When it is not necessary to distinguish between the liquid ejection heads of each color, they are collectively referred to as "liquid ejection head 1." The liquid ejection head module according to the present invention can be implemented in any form, including the example shown in FIG. 1, and is not limited to other forms.

[0014] (Description of the configuration of the liquid ejection head) 2 is a perspective view of various liquid ejection head modules to which the present disclosure can be applied. The liquid ejection head 1 has a liquid ejection head main body 1a on which a plurality of liquid ejection substrates 2, each having a nozzle 3, are arranged. Ink to be ejected is supplied from a liquid tank (not shown) to the liquid ejection substrate 2 via a common supply port (not shown) in the liquid ejection head main body 1a.

[0015] FIG. 3(a) shows a view of the liquid ejection substrate of the liquid ejection head module of the present disclosure, viewed from the nozzle side and from the opposite side. FIG. 3(b) is a schematic cross-sectional view taken along line AA in FIG. 3(a). FIG. 3(c) is a partially enlarged view of FIG. 3(b). The liquid ejection substrate 2 is composed of four substrates: a nozzle substrate 201, an actuator substrate 202, a flow path substrate 203, and a damper substrate 304. Nozzles 3 are formed on the nozzle substrate 201, and multiple nozzles 3 are arranged along the X direction of the substrate to form a nozzle row, and multiple nozzle rows are further formed in the Y direction. The actuator substrate 202 has pressure chambers 11, a vibration plate 17, and pressure-generation elements 18. The flow path substrate 203 has grooves that form voids 19 surrounding the individual flow paths 12, the common flow path 13, and the pressure-generation elements 18. When the pressure-generating element 18 is a piezoelectric element, a gap 19 is required to efficiently transmit deformation of the piezoelectric element caused by application of voltage to the vibration plate 17. The damper substrate 304 has a damper film 300, a damper chamber 301, and a common opening 15. Ink is supplied from the common opening 15 formed in the damper substrate 304 to the nozzle substrate 201 via the flow path substrate 203, and the ink is ejected from the nozzles 3 and applied to the recording medium 111. An electric board (not shown) for supplying power and signals necessary for ejecting liquid is disposed in the liquid ejection head main body 1a, and is connected to the terminals 10a of each liquid ejection substrate 2 by wiring (not shown). The liquid ejection head according to the present disclosure can be embodied in any form, including the example of FIG. 2, and is not limited to other forms.

[0016] (Nozzle arrangement, damper arrangement, and explanation of the air vent) FIG. 4(a) is a partially enlarged planar perspective view of a liquid ejection substrate 2 of a liquid ejection head according to the present disclosure, viewed from the side opposite the nozzle 3. FIG. 4(b) is a cross-sectional view taken along line BB in FIG. 4(a), and FIG. 4(c) is a cross-sectional view taken along line CC in FIG. 4(a). FIG. 4(d) is a cross-sectional view taken along line DD in FIG. 4(a). As shown in FIG. 4(a), the liquid ejection head 1 has a plurality of nozzle arrays arranged in the X direction, each of which includes a nozzle 3, a pressure chamber 11, an individual flow path 12 communicating with the pressure chamber 11, and a pressure-generating element 18 that generates pressure in the pressure chamber 11. As shown in FIG. 4(b), a pressure-generating element 18 is disposed at a position corresponding to each nozzle 3, for ejecting liquid by pressure. Along each nozzle array, an individual supply flow path 12a that forms the individual flow path 12 extends on one side, and an individual recovery flow path 12b that forms the individual flow path 12 extends on the other side. The individual supply flow paths 12a and the individual recovery flow paths 12b are flow paths that extend in the Z direction and are provided in the liquid ejection substrate, and each communicates with a nozzle 3. The individual supply flow paths 12a and the individual recovery flow paths 12b are each connected to a common flow path 13 that is composed of a common supply flow path 13a and a common recovery flow path 13b. The individual openings are the connections between the individual supply flow paths 12a and the individual recovery flow paths 12b and the common supply flow path 13a and the common recovery flow path 13b. A damper structure 302 composed of a damper chamber 301 and a damper film 300 is formed on the surface opposite the surface that has the individual openings. A common opening 15 composed of a common supply opening 15a and a common recovery opening 15b is formed in a damper substrate 304 on which the damper structure 302 is formed, for connecting the common supply flow path 13a and the common recovery flow path 13b, respectively. The common supply flow path 13a and the common recovery flow path 13b are formed to extend in the X direction, which is the direction along the nozzle row, and are formed on the surface opposite the ejection surface of the pressure generating element 18 in the Z direction in which the liquid is ejected.

[0017] The damper chamber 301 is open to the atmosphere by having air communication holes 303 (FIGS. 4(a), 4(c), and 4(d)) at both ends of the damper structure 302 in the X direction. Furthermore, by forming a damper structure 302 for each nozzle row (FIG. 4(a)), the pressure-generating elements 18 in each nozzle row can be arranged at high density. Furthermore, by extending the damper structure 302 in the X direction of the nozzle row and ensuring damping performance, the length in the Y direction can be shortened. By shortening the length of the damper structure 302 in the Y direction, the distance between adjacent nozzle rows in the Y direction can be shortened. This enables the miniaturization of the liquid ejection substrate 2 and the liquid ejection head. For example, in FIG. 4, the pressure chambers 11 corresponding to the pressure-generating elements 18 in each nozzle row have a length of 110 μm in the X direction, and the pressure chambers and nozzles are arranged at intervals of 150 dpi. Furthermore, by offsetting such nozzle rows in the X direction to form four rows, a high-density nozzle arrangement of 600 dpi can be achieved on the recording medium. In this embodiment, the nozzle array is four rows and the configuration is 600 dpi, but the present invention is not limited to this, and the nozzle array may be eight rows and the configuration is 1200 dpi.

[0018] Next, we will explain the flow of liquid within the liquid ejection substrate 2. When liquid is supplied to the common supply opening 15a, it passes through the common supply channel 13a, the individual supply channels 12a of each element, the pressure chambers 11, and the nozzles 3, passes through the individual recovery channels 12b, and flows through the common recovery channel 13b to the common recovery opening 15b. As a result, the liquid supplied from the common supply opening 15a flows to the common recovery opening 15b and can be recovered. When a pressure difference is applied from the outside to the common supply opening 15a and the common recovery opening 15b using a pump or hydraulic head pressure, the liquid can be circulated, and by suctioning the nozzles 3 from the ejection surface 5 while the liquid is circulating, the liquid can be filled inside the nozzles, thereby achieving nozzle circulation.

[0019] The increased density associated with nozzle circulation as described above results in a configuration in which each pressure chamber 11 is located close to each other within a nozzle row or between nozzle rows. Furthermore, adjacent nozzle rows share a common supply and recovery flow path. This raises concerns about crosstalk, which could result from pressure waves being transmitted to other pressure chambers 11 within or between nozzle rows and affecting ejection characteristics. In this embodiment, by arranging a damper structure 302 along the nozzle row direction, which is the X direction in the figure, it is possible to achieve a high-density nozzle arrangement and a compact liquid ejection head while also absorbing pressure waves from crosstalk.

[0020] The pressure generated in each pressure chamber 11 is transmitted through the individual supply flow paths 12a and the individual recovery flow paths 12b to the common supply flow path 13a and the common recovery flow path 13b, thereby propagating the pressure to other pressure chambers 11. Therefore, by providing the damper structure 302 at a position facing the individual supply flow paths 12a and the individual recovery flow paths 12b, the pressure from the individual supply flow paths 12a and the individual recovery flow paths 12b can be absorbed before it is transmitted to the common supply flow path 13a and the common recovery flow path 13b. For this reason, the damper structures 302 and the common supply openings 15a or the common recovery openings 15b are formed alternately on the damper substrate 304. In this embodiment, the flow paths and damper structures are arranged in the following order from left to right in the Y direction on the paper surface of FIG. 4(a): common supply opening 15a, damper structure 302, common recovery opening 15b, damper structure 302.

[0021] The liquid ejection head 1 may be used in different ambient environments, such as high pressure or high temperature and humidity. If the damper structure does not have the air vent 303 as in this embodiment, the interior of the damper chamber of the damper structure is sealed. Therefore, changes in atmospheric pressure can cause a pressure difference between the common flow path and the damper chamber, causing the gas in the damper chamber to expand or contract. Furthermore, when used in relatively high-temperature or cold climates, the gas inside the damper chamber thermally expands or contracts, causing changes in pressure. When a pressure difference occurs between the inside and outside of the sealed damper chamber, a corresponding biasing force acts on the damper membrane in a direction toward the outside or inside of the damper chamber. When this biasing force is applied, the damper membrane already undergoes a corresponding deformation, making it more difficult to deform when absorbing pressure during ejection. This changes the change characteristics (compliance characteristics) of the damper membrane. As a result, desired damping performance may not be achieved, and crosstalk pressure waves may not be sufficiently absorbed.

[0022] In contrast to this, according to this embodiment, by providing the atmosphere communication hole 303, the pressure inside the damper chamber 301 can be made equal to the pressure in the ambient environment even if the temperature or pressure of the ambient environment changes, thereby reducing or eliminating the pressure difference between the inside and outside of the damper chamber 301. As a result, the compliance characteristics of the damper membrane 300 can be kept constant, and crosstalk pressure waves can be sufficiently absorbed.

[0023] In this embodiment, as shown in FIG. 4, the atmosphere communication hole 303 is formed on the outer periphery of the liquid ejection substrate 2 on the surface opposite the ejection surface 5, at a position away from the common opening 15, which has the following advantages.

[0024] A member for supplying and recovering liquid to and from the common opening 15 is disposed on the surface of the damper substrate 304 on which the atmosphere communication hole 303 is formed. Since liquid is supplied, if the common opening 15 and the atmosphere communication hole 303 are located close to each other, the adhesive strength of the members may be reduced, resulting in liquid leakage. Therefore, by providing the atmosphere communication hole 303 at a position away from the common opening 15, the adhesive strength of the members can be ensured. Furthermore, the common opening 15 can be formed on the inner side of the liquid ejection substrate 2, which reduces the flow resistance of the liquid flowing to each liquid ejection element 18 and allows for smooth supply and recovery of the liquid. Furthermore, by arranging the atmosphere communication hole 303 on the outer periphery of both ends of the individual flow paths 12 of each nozzle row, the common opening 15 may be brought closer to both ends of the individual flow paths 12.

[0025] Furthermore, by forming the atmosphere communication holes 303 on both ends of the damper structure 302, the damper chamber 301 can be maintained at atmospheric pressure even if the atmosphere communication hole 303 on one side is blocked.

[0026] Furthermore, it is preferable that the atmosphere communication hole 303 be formed to have the same size as the common opening 15, thereby facilitating the processing of the damper substrate 304. From the viewpoint of the strength of the damper substrate 304, it is preferable that the depth (length in the Z direction) of the atmosphere communication hole 303 formed in the damper substrate 304 be greater than the depth of the damper chamber 301. It is preferable that the width (length in the Y direction) of the atmosphere communication hole 303 be smaller than the width of the damper chamber 301, thereby preventing the intrusion of foreign matter such as dust into the damper chamber. In other words, it is preferable that the width of the atmosphere communication hole 303 in a direction parallel to the surface of the damper substrate 304 and intersecting the direction in which the damper chamber 301 extends be smaller than the width of the damper chamber 301.

[0027] FIG. 5 is a cross-sectional view of the liquid ejection substrate showing the first modification of FIG. 4(a).

[0028] As a first modification of the first embodiment, as shown in Fig. 5, a damper substrate 304 has a damper film 300, a damper chamber 301, and a common opening 15. In detail, in the first embodiment, four substrates are processed and then bonded together to form the liquid ejection substrate 2. However, in this modification, in order to adjust the thickness of the common flow path 13 in the Z direction, the flow path substrate 203 may be divided into two substrates, substrate 204 and substrate 205, and five substrates may be bonded together. Separating the substrates into substrate 204 and substrate 205 makes processing easier.

[0029] FIG. 6 is a cross-sectional view of the liquid ejection substrate showing the second modification of FIG. 4(a).

[0030] 6, a configuration may be adopted in which a common flow path 206 is further provided in the damper substrate 304 to reduce the flow resistance of the liquid. In this case, from the viewpoint of the strength of the damper substrate 304, it is preferable that the depth (length in the Z direction) of the damper chamber 301 is smaller than the depth of the common flow path 206.

[0031] The nozzle substrate 201, actuator substrate 202, flow path substrate 203, and damper substrate 304 can each be formed from a silicon substrate or the like. The damper film 300 is formed from an elastic material, and for example, a resin material such as polyimide or polyamide can be used. Note that the configuration, material, and number of the substrates that form the liquid ejection substrate 2 are not limited to this example.

[0032] As in this embodiment, by providing the damper structure 302 and the atmosphere communication hole 303 on the surface opposite the ejection surface 5, it is possible to maintain the desired damper performance even if the environment around the liquid head fluctuates.

[0033] (Second embodiment) A second embodiment of the present disclosure will be described. Descriptions of the basic configuration of the present disclosure and functions and configurations similar to those of the first embodiment will be omitted, and differences will be described. In this embodiment, another example of the atmosphere communication hole 303 will be described with reference to FIG. 7.

[0034] Fig. 7(a) is an enlarged planar perspective view of a portion of the liquid ejection substrate 2. Fig. 7(b) is a cross-sectional view taken along line CC in Fig. 7(a), and Fig. 7(c) is a cross-sectional view taken along line DD in Fig. 7(a).

[0035] The second embodiment differs from the first embodiment in that an atmosphere communication hole 305 is formed in the damper substrate 304. Specifically, as shown in FIG. 7 , the atmosphere communication hole 305 is formed in the damper substrate 304. The atmosphere communication hole 305 is formed at both ends of the damper chamber 301 so as to open in a direction parallel to the ejection surface 5, and is formed to a depth equivalent to the depth (length in the Z direction) of the damper chamber. Forming the atmosphere communication hole 305 at both ends of the damper chamber 301 and to a depth equivalent to that of the damper chamber 301 can facilitate processing of the damper substrate 304. Furthermore, the common openings 15 may be formed closer to both ends of the individual flow paths 12 than in the first embodiment, or the number of common openings 15 may be increased. Furthermore, when arranging components for supplying or recovering liquid to or from the common openings 15, areas other than the common openings 15 can be used as adhesive areas, which is preferable because it improves adhesive strength.

[0036] It is preferable that the width of the atmosphere communication hole 305 in the Y direction is smaller than the width of the damper chamber 301 in the Y direction, so that foreign matter such as dust can be prevented from entering the damper chamber 301.

[0037] In this way, by providing the damper structure 302 on the surface opposite to the ejection surface 5 and providing the atmosphere communication hole 305 so that it opens in a direction horizontal to the ejection surface 5, it is possible to maintain the desired damping performance even if the environment around the liquid ejection head changes. In addition, it is possible to improve the adhesive strength with the members that supply and recover liquid to the common opening 15.

[0038] (Third embodiment) A third embodiment of the present disclosure will be described. Descriptions of the basic configuration of the present disclosure and functions and configurations similar to those of the first embodiment will be omitted, and differences will be described. In the third embodiment, another example of the atmosphere communication hole 303 of the second embodiment will be described with reference to FIG. 8.

[0039] Fig. 8(a) is an enlarged planar perspective view of a portion of the liquid ejection substrate 2. Fig. 8(b) is a cross-sectional view taken along line CC in Fig. 8(a), and Fig. 8(c) is a cross-sectional view taken along line DD in Fig. 8(a).

[0040] The third embodiment differs from the first and second embodiments in that an atmosphere communication hole 306 is formed in the damper substrate 304, and atmosphere communication openings 307 are formed in the nozzle substrate 201, the actuator substrate 202, and the flow path substrate 203. Specifically, as shown in FIG. 8 , the atmosphere communication hole 306 is formed in the damper film 300 of the damper substrate 304, and the atmosphere communication opening 307 is formed so as to penetrate the flow path substrate 203, the actuator substrate 202, and the nozzle substrate 201, and opens at the ejection surface to communicate with the atmosphere. The configuration shown in FIG. 8 achieves the same effect as the second embodiment. By forming the atmosphere communication opening 307, the common openings 15 can be positioned closer to both ends of the individual flow paths 12 than in the first embodiment, and it is preferable to increase the number of common openings 15. Furthermore, when arranging components for supplying or recovering liquid to the common openings 15, areas other than the common openings 15 can be used as adhesive areas, which is preferable because it improves adhesive strength.

[0041] FIG. 9 is a cross-sectional view taken along line DD of FIG. 8(a) showing the first modification.

[0042] 9, as a first modification of the third embodiment, a damper substrate 304 has atmosphere communication holes 306 formed therein, and is formed larger than the nozzle substrate 201, the actuator substrate 202, and the flow path substrate 203. The atmosphere communication holes 306 are formed at both ends of the damper film 300 in the X direction, and communicate with the atmosphere. This makes it possible to maintain the desired damping performance even if the environment around the liquid ejection head fluctuates.

[0043] Furthermore, when using this modified example to remove droplets adhering to the ejection surface 5 with a wiper, the wiper does not come into contact with the atmosphere-communicating hole 306, thereby providing the effect of preventing droplets from entering the atmosphere-communicating hole 306.

[0044] FIG. 10 is a cross-sectional view taken along line DD of FIG. 9 showing Modification 2. In FIG.

[0045] 10, in a second modification of the third embodiment, a damper substrate 304 has an atmosphere communication hole 306 formed therein, and atmosphere communication openings 307 are formed on both ends of the flow path substrate 203 in the same Z direction as the common flow path 13, so as to communicate with the atmosphere communication hole 306. This makes it possible to maintain the desired damping performance even if the environment around the liquid ejection head fluctuates.

[0046] By forming it at the same position in the Z direction as the common flow path 13 and at the same depth, it can be produced by collectively processing the flow path substrate 203. By making the width in the Y direction of the atmosphere communication opening 307 in Fig. 10 smaller than the width of the damper chamber 301, as in Fig. 7(a), it becomes difficult for foreign matter such as dust to enter from the outside.

[0047] In this way, by providing the damper structure on the surface opposite the ejection surface and providing the atmosphere communication hole in the same direction as the ejection surface, the desired damping performance can be maintained even if the environment around the liquid ejection head changes. Also, the adhesive strength with the member for supplying and recovering liquid to the common opening 15 can be improved.

[0048] (Fourth embodiment) A fourth embodiment of the present disclosure will be described. Descriptions of the basic structure of the present disclosure and the same functions and configurations as those of the first embodiment will be omitted, and only differences will be described.

[0049] FIG. 11(a) is a planar perspective view of an enlarged portion of a liquid ejection substrate 2a of a liquid ejection head according to the present disclosure. FIG. 11(b) is a cross-sectional view taken along line BB in FIG. 11(a). FIG. 11(c) is a cross-sectional view taken along line DD in FIG. 11(a). As shown in FIG. 11(a), a common supply opening 15a for supplying liquid is formed approximately at the center of the liquid ejection substrate 2a. When liquid is supplied to the common supply opening 15a, the liquid passes through the common supply channel 13a, the individual supply channels 12a of each element, and is then supplied to the pressure chambers 11 and the nozzles 3. Unlike the first embodiment, this configuration does not circulate the liquid. As with the first embodiment, this configuration also features close proximity within and between nozzle rows. Furthermore, adjacent nozzle rows share a common supply channel 13a. Therefore, pressure waves may be transmitted to other pressure chambers 11 within or between adjacent nozzle rows, raising concerns about crosstalk that could affect ejection characteristics. As shown in FIG. 11, by providing an atmosphere communication hole 303, it is possible to maintain the desired damping performance even if the environment around the liquid ejection head changes.

[0050] (Fifth embodiment) A liquid ejection substrate according to a fifth embodiment of the present disclosure will be described. Note that a description of the basic configuration of the present disclosure and functions and configurations similar to those of the first embodiment will be omitted, and only differences will be described. In this embodiment, the liquid ejection substrate will be described using FIG.

[0051] FIG. 12 is a plan view showing a portion of a liquid ejection substrate 2 according to a fifth embodiment. Compared to the configuration shown in FIG. 12, the number of common supply openings 15a and common recovery openings 15b provided in each common supply channel 13a and common recovery channel 13b is increased. This allows for more efficient ink supply to and ink recovery from the liquid ejection substrate 2. The atmosphere communication holes 303 are concentrated at the ends of the nozzle array. The damper chambers 301 are connected by communication spaces located closer to the chip end than the common supply openings 15a and common recovery openings 15b, and all are at the same atmospheric pressure via the atmosphere communication holes 303. This configuration ensures sufficient distance between each common supply opening 15a and common recovery opening 15b, even if the number of common supply openings 15a and common recovery openings 15b is increased. Therefore, sufficient bonding area and adhesive strength can be ensured when bonding substrates for ink supply. Ink leakage between the common supply openings 15a and common recovery openings 15b can be prevented.

[0052] The damper chamber 301 is connected to the atmosphere outside the head via the atmosphere communication hole, so that the liquid ejection module is not affected by the operating environment. Furthermore, since the damper chamber 301 is connected to the atmosphere, the compliance performance of the damper film 300 is not reduced, and the effect of reducing pressure fluctuations is suppressed. In this way, by connecting the inside of the damper chamber 301 to the atmosphere outside the head, it is possible to suppress pressure fluctuations occurring in one pressure chamber 11 from affecting other pressure chambers 11. Therefore, crosstalk between pressure chambers 11 connected via the common flow path 13 is reduced, and unintended fluctuations in the characteristics of droplets ejected from the nozzles 3 can be suppressed. This makes it possible to suppress a decrease in the quality of recording on a recording medium 111 by a liquid ejection device 101 having a liquid ejection head module 1.

[0053] (Sixth embodiment) A second embodiment of the present disclosure will be described. Descriptions of the basic configuration of the present disclosure and functions and configurations similar to those of the first embodiment will be omitted, and only differences will be described.

[0054] 13 is a plan view showing a portion of a liquid ejection substrate 2 according to the sixth embodiment. Compared to the configuration of the sixth embodiment, each pressure chamber 11 is provided with an individual flow path 12, and a common flow path 13 is provided to connect the plurality of individual flow paths 12. The common flow paths 13 are connected to the individual flow paths 12 of the two nozzle rows, one common flow path 13, and damper chambers 301 are provided at positions facing the individual flow paths 12. A common opening 15 having a large opening in the nozzle row direction (X direction) is provided for the two common flow paths 13. Atmosphere communication holes 303 are provided at both ends of the damper chamber 301, and are connected to the atmosphere outside the liquid ejection head.

[0055] In this embodiment, damper chambers 301 are provided at both ends of the individual flow paths 12 of two nozzle rows so as to face each other, but a common flow path 13 may also be formed so as to connect to the individual flow paths 12 of three or more nozzle rows.

[0056] According to the configuration of this embodiment, an area for bonding a substrate for ink supply is secured around the common opening 15, so that a sufficient bonding area can be secured when bonding a substrate for ink supply, and sufficient bonding strength can be obtained. Similarly to the common opening 15, a sufficient bonding area can also be secured for the atmosphere communication hole 303. Even when similar structures are arranged side by side on the same liquid ejection substrate, a sufficient bonding area can be secured between the common openings 15, and sufficient bonding strength can be obtained. Even when multiple atmosphere communication holes are provided between the common opening 15 and the atmosphere communication hole 303, ink leakage between the common openings 15 can be prevented.

[0057] By connecting the damper chamber 301 to the atmosphere via the atmosphere communication hole 303, the liquid ejection module is not affected by the usage environment, the compliance performance of the damper film 300 does not decrease, and the effect of reducing pressure fluctuations can be suppressed. In this way, by connecting the damper chamber 301 to the atmosphere, it is possible to suppress pressure fluctuations occurring in one pressure chamber 11 from affecting other pressure chambers 11. Therefore, crosstalk between the pressure chambers 11 that communicate with each other via the common flow path 13 is reduced, and unintended fluctuations in the characteristics of droplets ejected from the nozzles 3 can be suppressed. This makes it possible to suppress deterioration in the print quality of the liquid ejection device 101 having the liquid ejection head module 1 on the recording medium 111.

[0058] (Seventh embodiment) The configuration of a liquid ejection substrate 2 according to the seventh embodiment of the present disclosure will be described. Descriptions of the basic configuration of the present disclosure and functions and configurations similar to those of the first embodiment will be omitted, and only differences will be described.

[0059] Figure 14 is a schematic diagram of the liquid ejection substrate 2 of this embodiment. Figures 14(a) and (b) are schematic plan views of the liquid ejection substrate 2 as seen from the ejection surface, and Figure 14(c) is a plan view of the liquid ejection substrate 2 as seen from the side opposite the ejection surface. Figure 14(d) is a cross-sectional view taken along line A-A' in Figure 14(a).

[0060] 14(d), the liquid ejection substrate 2 of this embodiment comprises a nozzle substrate 201, an actuator substrate 202, and a flow path substrate 203 bonded thereon, and a plurality of nozzles 3 are arranged on the nozzle substrate 201. A plurality of nozzles 3 are arranged to form a nozzle row.

[0061] The actuator substrate 202 is preferably made of a material such as a semiconductor substrate on whose surface electronic devices such as energy generating elements, electrical circuits, electrical wiring, and temperature sensors can be arranged by semiconductor processing, and on which flow paths can be formed by MEMS processing. The nozzle substrate 201 and flow path substrate 203 can be made of any material, such as a resin substrate on which nozzles are formed by laser processing, or an inorganic plate on which nozzles are formed by dicing. The nozzle substrate 201 and flow path substrate 203 can be made of any material, such as a photosensitive resin material on which nozzles and flow paths are formed by photocuring, or a semiconductor substrate on which nozzles and flow paths are formed by MEMS processing.

[0062] In this embodiment, the liquid ejected from all the nozzles is ink of the same color, but different colors may be used for each nozzle row.Furthermore, the liquid ejected may be a liquid other than ink.

[0063] At positions corresponding to each nozzle 3, a pressure chamber 11 made of an actuator substrate 202 and a diaphragm 17 made of the actuator substrate 202, which is a deformable wall surface of the pressure chamber 11, are formed, and a piezoelectric generating element 18 is integrally provided on the diaphragm 17. The piezoelectric generating element 18 deforms the diaphragm 17 based on a pulse signal input via electrical wiring (not shown) provided on the actuator substrate 202, pressurizing the liquid in the pressure chamber 11 and ejecting the liquid from the nozzle 3 using the pressure. Note that the actuator substrate 202 and the diaphragm 17 are not limited to being separate components. For example, the actuator substrate 202 and the diaphragm 17 can be integrally formed from the same component using an SOI (Silicon on Insulator) substrate. That is, an SOI substrate formed by depositing a silicon oxide film, a silicon layer, and a silicon oxide film in this order on a silicon substrate can be used as the actuator substrate 202, and the diaphragm 17 can be formed from the silicon oxide film, the silicon layer, and the silicon oxide film. In this way, the vibration plate 17 includes a plate made of a material formed as a film on the surface of the actuator substrate 202. Furthermore, in this embodiment, the method of discharging liquid is described as using the deformation of a piezoelectric element, but it may also be a method of discharging liquid by heating the liquid with, for example, a heater and using the phenomenon of bubbling.

[0064] 14(b) and 14(c), a common supply channel 13a and a common recovery channel 13b extend along the nozzle row 3a in the channel substrate 203 at positions on both sides of each nozzle 3. The channel substrate 203 is connected to the pressure chambers 11 via the individual supply channels 12a and individual recovery channels 12b, and the liquid flows from the common supply channel 13a through the individual supply channel 12a into the pressure chamber 11. A circulation flow is then formed in which the liquid returns to the common recovery channel 13b via the other individual recovery channel 12b. In this embodiment, two common channels 13 are provided for one pressure chamber 11, but the two common channels 13 may also be connected to one another.

[0065] A damper chamber forming substrate 304 is laminated on the flow path substrate 203. The damper chamber forming substrate 304 is formed with a damper chamber 301, in which a groove formed in the damper chamber forming substrate 304 is sealed with a damper film 300 at a position facing the individual supply flow path 12a and the individual recovery flow path 12b.

[0066] The damper film 300 is preferably made of a metal thin film or an inorganic thin film that is resistant to organic solvents, and preferably has a thickness of 10 μm or less. An atmosphere communication hole 303 is formed on the surface of the damper chamber 301 facing the damper film 300. A common supply opening 15a and a common recovery opening 15b that communicate with the common supply flow path 13a and the common recovery flow path 13b are formed on the surface of the damper chamber forming substrate 304 that contacts the flow path substrate 203. The common supply opening 15a and the common recovery opening 15b communicate with a support plate 308 on the surface opposite the flow path substrate 203, and each supply ink supplied from the support plate 308 to the pressure chamber 11 and recover ink from the pressure chamber 11 to the support plate 308.

[0067] As described above, in this embodiment, the damper chamber 301 is provided with an atmosphere communication hole 303, creating an environment inside the damper chamber 301 equivalent to the atmosphere. This suppresses changes in the compliance characteristics of the damper membrane 300 due to differences in environmental temperature and atmospheric pressure, thereby achieving desired damping performance. Furthermore, the damper membrane 300 is disposed on the opposing surfaces of the individual supply flow paths 12a and the individual recovery flow paths 12b, and the damper chamber 301 is disposed on the opposite side of the flow path substrate 203, sandwiching the damper membrane 300 therebetween. Furthermore, the atmosphere communication hole 303 is disposed on the opposite side of the flow path substrate 203 from the damper chamber 301. By arranging the various components so that they are stacked in the ejection direction of the nozzles 3, the area in the ejection surface direction can be minimized, enabling high-density nozzle arrangement and a more compact liquid ejection head 1.

[0068] (Eighth embodiment) An eighth embodiment of the present disclosure will be described. Descriptions of the basic configuration of the present disclosure and functions and configurations similar to those of the seventh embodiment will be omitted, and differences will be described. Fig. 15(a) is a plan view of a liquid ejection substrate 2 of this embodiment, and Fig. 15(b) is a cross-sectional view taken along line A-A' in Fig. 15(a).

[0069] In the seventh embodiment, the pressure chamber 11 was provided with an individual supply flow path 12a and an individual recovery flow path 12b, forming a flow in which ink circulated through the pressure chamber 11. However, in this embodiment, only the individual supply flow path 12a is provided, and ink is ejected from the nozzle 3 without circulating. In this embodiment as well, by arranging the components so that they are stacked in the ejection direction of the nozzle 3, it is possible to minimize the area in the ejection surface direction, enabling a high-density arrangement of nozzles and a miniaturization of the liquid ejection head 1.

[0070] (Ninth embodiment) A ninth embodiment of the present disclosure will be described. Descriptions of the basic configuration of the present disclosure and functions and configurations similar to those of the seventh embodiment will be omitted, and differences will be described. Fig. 16 is a plan view of a liquid ejection substrate of a liquid ejection head according to the ninth embodiment.

[0071] As shown in FIG. 14(d), a support plate 308 is bonded to the damper substrate 304. The support plate 308 is provided with a plurality of liquid supply ports 31, liquid recovery ports 32, and air vent holes 303, corresponding to the opening positions of the damper substrate 304. As shown in FIG. 16, liquid is supplied to the liquid ejection substrate 2 through the liquid supply ports 31, or liquid is recovered from the liquid ejection substrate 2 through the liquid recovery ports 32. The air vent holes 303 form a path connecting the damper chamber 301 to the outside. The support plate 308 can be made of any material, such as a resin substrate in which nozzles are formed by laser processing or an inorganic plate in which nozzles are formed by dicing. The support plate 308 can also be made of any material, such as a photosensitive resin material in which nozzles and flow channels are formed by photocuring or a semiconductor substrate in which nozzles and flow channels are formed by MEMS processing. In this embodiment, the support plate 308 and the liquid ejection substrate 2 are bonded together, but a sufficient adhesive area is required between the support plate 308 and the damper substrate 304 to prevent ink leakage. On the other hand, to achieve high image quality, it is desirable to minimize the size of the liquid ejection substrate. Furthermore, while the common supply channel 13a, the common recovery channel 13b, and the damper chamber 301 extend along the nozzle row, the pressure and temperature of the liquid and atmosphere inside must be as uniform as possible. Therefore, it is desirable to arrange the liquid supply port 31, the liquid recovery port 32, and the atmosphere communication hole 303 symmetrically about the center of the liquid ejection substrate 2. To satisfy these requirements, in this embodiment, the atmosphere communication hole 303 is arranged on the outside so as to sandwich the liquid supply port or recovery port. While the liquid supply port or recovery port requires a large adhesive area to prevent liquid leakage, the atmosphere communication hole 303 does not require as much adhesive area as the liquid, since even if leakage occurs, it is air. If the liquid supply port or recovery port is arranged so as to sandwich the atmosphere communication hole 303, a large adhesive area is required between them and between the liquid supply port or recovery port and the outside. On the other hand, if the atmosphere communication hole 303 is arranged so as to sandwich the liquid supply port or recovery port, a large adhesive area is required only between the liquid supply port or recovery port and the atmosphere communication hole 303, and the total adhesive area can be reduced, thereby making it possible to make the liquid ejection substrate 2 smaller.

[0072] <Other embodiments> The present disclosure includes configurations typified by the following liquid ejection head examples.

[0073] <Configuration 1> a nozzle substrate having a plurality of nozzles for ejecting liquid; a flow path substrate having a plurality of pressure chambers respectively communicating with the plurality of nozzles, a plurality of individual flow paths respectively communicating with the plurality of pressure chambers, a plurality of pressure generating means for generating pressure in the plurality of pressure chambers respectively, and a common flow path communicating with the plurality of individual flow paths; a damper substrate having a damper film disposed so as to face a surface facing an opening surface of a flow channel communicating with the common flow channel, and a damper chamber one surface of which is covered by the damper film; A liquid ejection head having a liquid ejection substrate comprising: The liquid ejection head is characterized in that the liquid ejection substrate has an atmosphere communication hole that connects the inside of the damper chamber to the atmosphere.

[0074] <Configuration 2> The liquid ejection head according to configuration 1, wherein the damper substrate is provided at a position where a substrate on which the pressure chambers, the individual flow paths, the pressure generating means, and the common flow path are provided is interposed between the damper substrate and the nozzle substrate.

[0075] <Configuration 3> 3. The liquid ejection head according to configuration 1 or 2, wherein the atmosphere communication hole is formed in a direction horizontal to the ejection surface of the nozzle substrate on which the plurality of nozzles are formed.

[0076] <Configuration 4> 4. The liquid ejection head according to any one of configurations 1 to 3, wherein the atmosphere communication hole is formed on the ejection surface side of the nozzle substrate on which the plurality of nozzles are formed.

[0077] <Configuration 5> A liquid ejection head described in any one of configurations 1 to 4, characterized in that the atmosphere communication holes are formed at both ends of the damper chamber in the direction in which the damper chamber extends, when viewed from a direction perpendicular to the surface of the damper substrate.

[0078] <Configuration 6> A liquid ejection head according to any one of configurations 1 to 5, characterized in that, when viewed from a direction perpendicular to the surface of the damper substrate, the atmosphere communication hole is formed closer to the outer periphery of the damper substrate than the plurality of individual flow paths.

[0079] <Configuration 7> The liquid ejection head according to any one of configurations 1 to 6, wherein the width of the atmosphere communication hole in a direction parallel to the surface of the damper substrate and intersecting the direction in which the damper chamber extends is smaller than the width of the damper chamber.

[0080] <Configuration 8> 3. The liquid ejection head according to configuration 2, wherein the size of the air communication hole in a direction perpendicular to the surface of the flow path substrate is the same as the height of the common flow path.

[0081] <Configuration 9> 3. The liquid ejection head according to configuration 2, wherein the size of the atmosphere communication hole in a direction perpendicular to the surface of the flow path substrate is larger than the size of the damper chamber.

[0082] <Configuration 10> 10. The liquid ejection head according to any one of configurations 1 to 9, wherein the atmosphere communication hole is formed in the damper chamber.

[0083] <Configuration 11> The liquid ejection head according to configuration 3, wherein the atmosphere communication hole is formed in the flow path substrate so as to open in a direction horizontal to the ejection surface.

[0084] <Configuration 12> a support plate disposed on a surface of the damper substrate opposite to a surface adjacent to the flow path substrate, the support plate has the atmosphere communication hole and a supply port communicating with the common flow path, 12. A liquid ejection head according to any one of configurations 1 to 11, characterized in that, when viewed from a direction perpendicular to the surface of the support plate, the atmosphere communication hole is formed outside the support plate relative to the supply port.

[0085] <Configuration 13> 13. The liquid ejection head according to any one of configurations 1 to 12, wherein the size of the damper chamber in a direction perpendicular to the surface of the flow path substrate is smaller than the size of the common flow path.

[0086] <Configuration 14> 14. The liquid ejection head according to any one of configurations 1 to 13, wherein the flow path substrate has an individual flow path substrate that forms the individual flow paths and a common flow path substrate that forms the common flow path.

[0087] <Configuration 15> 15. The liquid ejection head according to configuration 14, having a structure in which the individual flow path substrate, the common flow path substrate, and the damper substrate are arranged in this order in a direction perpendicular to the surface of the liquid ejection substrate. [Explanation of symbols]

[0088] 1 Liquid ejection head 2 Liquid discharge board 3 nozzles 5 Discharge surface 11 Pressure Chamber 12 Individual flow paths 13 Common flow path 18 Pressure generating element (pressure generating means) 201 Nozzle substrate 203 Flow channel substrate 300 Damper membrane 301 Damper Room 303, 305, 306, atmospheric vent

Claims

1. a nozzle substrate having a plurality of nozzles for ejecting liquid; a flow path substrate having a plurality of pressure chambers respectively communicating with the plurality of nozzles, a plurality of individual flow paths respectively communicating with the plurality of pressure chambers, a plurality of pressure generating means for generating pressure in the plurality of pressure chambers respectively, and a common flow path communicating with the plurality of individual flow paths; a damper substrate having a damper film disposed so as to face a surface facing an opening surface of a flow channel communicating with the common flow channel, and a damper chamber one surface of which is covered by the damper film; A liquid ejection head having a liquid ejection substrate comprising: The liquid ejection head is characterized in that the liquid ejection substrate has an atmosphere communication hole that connects the inside of the damper chamber to the atmosphere.

2. 2. The liquid ejection head according to claim 1, wherein the damper substrate is provided at a position where a substrate on which the pressure chambers, the individual flow paths, the pressure generating means, and the common flow path are provided is interposed between the damper substrate and the nozzle substrate.

3. 2. The liquid ejection head according to claim 1, wherein the atmosphere communication hole is formed in a direction parallel to the ejection surface of the nozzle substrate on which the plurality of nozzles are formed.

4. 2. The liquid ejection head according to claim 1, wherein the atmosphere communication hole is formed on the ejection surface side of the nozzle substrate on which the plurality of nozzles are formed.

5. 2. The liquid ejection head according to claim 1, wherein the atmosphere communication holes are formed at both ends of the damper chamber in the direction in which the damper chamber extends when viewed from a direction perpendicular to the surface of the damper substrate.

6. 2. The liquid ejection head according to claim 1, wherein the atmosphere communication hole is formed closer to the outer periphery of the damper substrate than the plurality of individual flow paths when viewed from a direction perpendicular to the surface of the damper substrate.

7. 2. The liquid ejection head according to claim 1, wherein the width of the atmosphere communication hole in a direction parallel to the surface of the damper substrate and intersecting the direction in which the damper chamber extends is smaller than the width of the damper chamber.

8. 3. The liquid ejection head according to claim 2, wherein the size of the atmosphere communication hole in a direction perpendicular to the surface of the flow path substrate is the same as the height of the common flow path.

9. 3. The liquid ejection head according to claim 2, wherein the size of the atmosphere communication hole in a direction perpendicular to the surface of the flow path substrate is larger than the size of the damper chamber.

10. 2. The liquid ejection head according to claim 1, wherein the atmosphere communication hole is formed in the damper chamber.

11. 4. The liquid ejection head according to claim 3, wherein the atmosphere communication hole is formed in the flow path substrate so as to open in a direction parallel to the ejection surface.

12. a support plate disposed on a surface of the damper substrate opposite to a surface adjacent to the flow path substrate, the support plate has the atmosphere communication hole and a supply port communicating with the common flow path, 2. The liquid ejection head according to claim 1, wherein the atmosphere communication hole is formed outside the support plate relative to the supply port when viewed from a direction perpendicular to the surface of the support plate.

13. 2. The liquid ejection head according to claim 1, wherein the size of the damper chamber in a direction perpendicular to the surface of the flow path substrate is smaller than the size of the common flow path.

14. 2. The liquid ejection head according to claim 1, wherein the flow path substrate comprises an individual flow path substrate that forms the individual flow paths, and a common flow path substrate that forms the common flow path.

15. The liquid ejection head according to claim 14 , wherein the individual flow path substrate, the common flow path substrate, and the damper substrate are arranged in this order in a direction perpendicular to the surface of the liquid ejection substrate.

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