Liquid dispensing head and liquid dispensing device

Abstract

The present invention provides a liquid dispensing head that can suppress variations in dispensing speed in the nozzle arrangement area and thereby suppress a decrease in image quality. [Solution] A liquid discharge head 18 comprising a nozzle substrate 20 having a nozzle arrangement region 1a, a flow channel substrate 21 having a common flow channel 4, a piezoelectric element substrate 9 having individual flow channels 13, a diaphragm 7 and a piezoelectric element 8, a holding substrate 10 and a frame member 22 having other supply flow channels 11, wherein the size of the flow channel substrate 21 in the short direction is larger than the size of the piezoelectric element substrate 9 and the holding substrate 10 in the short direction, the flow channel substrate 21 and the frame member 22 are joined in the short direction outside the piezoelectric element substrate 9 and the holding substrate 10 either directly or via a member thinner than the piezoelectric element substrate 9, the common flow channel 4 and the other common flow channels 11 are joined to each other by an adhesive 5, and the length B of the joining region 5a between the common flow channel 4 and the other common flow channels 11 is longer than the length A of the nozzle arrangement region 1a.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device.

Background Art

[0002] Conventionally, a liquid ejection head employed in an inkjet type image forming apparatus is known. In this liquid ejection head, it is required to reduce the variation in the ejection speed of the liquid within the head for high image quality. As such a liquid ejection head, conventionally, a technique for creating piezoelectric elements for the head at high density using a MEMS (Micro Electro Mechanical Systems) process on a silicon substrate is known. The liquid ejection head is assembled by bonding a nozzle substrate, a flow path substrate, ink supply, and a frame member for holding each substrate to the piezoelectric element with an adhesive or the like.

[0003] Examples of the adhesive used for bonding include a UV curable adhesive, a two-component room temperature curable adhesive, a heat curable adhesive, etc. However, since the adhesive used for bonding also comes into contact with the ink, it is necessary to use an adhesive with high ink resistance. Among such adhesives, a heat curable adhesive may be used due to the relationship between ink resistance and manufacturing tact time. However, the piezoelectric element using the MEMS process, which are members bonded to each other, mainly uses a silicon material, and a resin material is used for the frame member and the like. When such dissimilar materials are heat-bonded to each other, residual stress occurs after bonding due to the difference in the linear expansion coefficient of the materials and the curing shrinkage of the adhesive (see FIG. 2).

[0004] To suppress the decrease in reliability of the liquid discharge head due to the residual stress mentioned above, a configuration has been proposed in which a nozzle, a flow path member, a supply path member, and a heater are provided, wherein the coefficient of linear expansion of the supply path member is greater than that of the flow path member, the flow path member and the supply path member are joined by a thermosetting adhesive, and the heater is provided on the supply path member (see, for example, "Patent Document 1"). According to this configuration, the case substrate is heated by the heater to expand the case substrate, which reduces the residual stress caused by the difference in the amount of shrinkage between the case substrate and the communication substrate after the thermosetting adhesive has hardened, and thus the reliability of the liquid discharge head can be easily improved. [Overview of the project] [Problems that the invention aims to solve]

[0005] In the aforementioned technology, stress is applied to the diaphragm by joining dissimilar materials. Therefore, controlling this stress by designing the head structure is crucial to reducing variations in ejection speed. However, conventional head structures have an incomplete control of stress due to differences in coefficient of thermal expansion, resulting in variations in ejection speed within the head and a decrease in image quality. In particular, the technology disclosed in "Patent Document 1" did not specify the wetting spread of the adhesive used to join the flow channel member and the supply channel member. If the length of the flow channel arrangement area in the flow channel member is shorter than the length of the nozzle arrangement area, and the length of the area where the adhesive wets is shorter than the length of the nozzle arrangement area, then the way in which stress is applied to each member during bonding and fixing will differ in the longitudinal direction of the nozzle arrangement area due to the difference in coefficient of linear expansion, which leads to a problem of large variations in discharge speed. The present invention aims to solve the above-mentioned problems and provide a liquid discharge head that can suppress variations in discharge speed in the nozzle arrangement region and thereby suppress a decrease in image quality. [Means for solving the problem]

[0006] The invention described in claim 1 comprises: a nozzle substrate having a nozzle arrangement region on which a plurality of nozzles for discharging liquid are arranged; a flow path substrate having a common flow path communicating with the nozzles; a piezoelectric element substrate having individual flow paths communicating with the nozzles; a diaphragm formed to cover the individual flow path; and a piezoelectric element provided in the individual flow path; a holding substrate having a recess in the vibration region of the piezoelectric element; and a frame member having another supply flow path communicating with the common flow path, wherein the size of the flow path substrate in the short direction is larger than the size of the piezoelectric element substrate and the holding substrate in the short direction; the flow path substrate and the frame member are joined in the short direction on the outside of the piezoelectric element substrate and the holding substrate either directly or via a member thinner than the piezoelectric element substrate; the common flow path and the other common flow path are joined to each other by an adhesive; and the length of the joining region between the common flow path and the other common flow path is longer than the length of the nozzle arrangement region. [Effects of the Invention]

[0007] According to the present invention, since the tensile stress generated during adhesive bonding and fixing acts uniformly throughout the entire nozzle arrangement area, variations in ejection speed near both ends can be suppressed, and an inkjet head is provided that can suppress variations in ejection speed within the nozzle arrangement area and suppress a decrease in image quality. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a liquid dispensing head to which one embodiment of the present invention can be applied. [Figure 2] This is a schematic diagram illustrating the residual stress caused by the difference in coefficient of thermal expansion when two components are bonded together. [Figure 3] This is a schematic cross-sectional view of the area around a piezoelectric element used in one embodiment of the present invention. [Figure 4] This is a plan view of the main parts of a conventional nozzle substrate, flow path substrate, and frame member. [Figure 5] Figure 4 is a schematic diagram showing the ink ejection speed in the inkjet head. [Figure 6] This is a plan view of the main parts of other conventional nozzle substrates, flow path substrates, and frame members. [Figure 7] Figure 6 is a schematic diagram showing the ink ejection speed in the inkjet head. [Figure 8] This is a plan view of the main parts of the nozzle substrate, flow path substrate, and frame member according to the first embodiment of the present invention. [Figure 9] Figure 8 is a schematic diagram showing the ink ejection speed in the inkjet head. [Figure 10] This is a plan view of the main parts of the nozzle substrate, flow path substrate, and frame member according to a second embodiment of the present invention. [Figure 11] Figure 10 is a schematic diagram showing the ink ejection speed in the inkjet head. [Figure 12] This is a plan view of the main parts of the nozzle substrate, flow path substrate, and frame member according to a second embodiment of the present invention. [Figure 13] A schematic front view of another liquid dispensing device equipped with a liquid dispensing head according to each embodiment of the present invention. [Figure 14] This is a schematic plan view illustrating a unit of another device equipped with a head according to each embodiment of the present invention. [Figure 15] This is a schematic plan view of yet another liquid dispensing device equipped with a liquid dispensing head according to each embodiment of the present invention. [Figure 16] This is a schematic side view of yet another liquid dispensing device equipped with a liquid dispensing head according to each embodiment of the present invention. [Figure 17] This is a schematic plan view illustrating a liquid discharge unit of yet another liquid discharge device equipped with a liquid discharge head according to each embodiment of the present invention. [Figure 18] A schematic front view illustrating another liquid dispensing unit of yet another liquid dispensing device equipped with a liquid droplet dispensing head according to each embodiment of the present invention. [Figure 19] A schematic front view of an electrode manufacturing apparatus, which is yet another liquid dispensing apparatus equipped with a liquid dispensing head according to each embodiment of the present invention.

Best Mode for Carrying Out the Invention

[0009] FIG. 1 is a schematic view of a discharge portion of an inkjet head as a liquid discharge head according to an embodiment of the present invention. In the figure, an inkjet head 18 includes a nozzle substrate 2 having a plurality of nozzles 1 for discharging ink at the lower part, and above it, a flow path substrate 3 joined to the nozzle substrate 2 and having individual flow paths 13 and a common flow path 4, and individual liquid chambers 6 communicating with the individual flow paths 13. Above the individual liquid chambers 6, there are provided a diaphragm 7 covering one surface of the individual liquid chambers 6, a piezoelectric element substrate 9 having a piezoelectric element 8 disposed on the diaphragm 7 for generating a driving force, a holding substrate 10 for holding the piezoelectric element substrate 9, and a frame member 12 joined to the flow path substrate 3 and having a common flow path 11 communicating with the common flow path 4. In FIG. 1, the horizontal direction is the short side direction of the inkjet head 18, and the depth direction (paper surface direction) is the long side direction of the inkjet head 18.

[0010] Here, the size of the flow path substrate 3 in the short side direction, that is, the horizontal direction in FIG. 1, is formed larger than the sizes of the piezoelectric element substrate 9 and the holding substrate 10 in the same direction, and the flow path substrate 3 and the frame member 12 are directly joined outside the piezoelectric element substrate 9 and the holding substrate 10 in FIG. 1. Note that the flow path substrate 3 and the frame member 12 may be joined via a member thinner than the piezoelectric element substrate 9.

[0011] On the surface of the flow path substrate 3 opposite to the surface to which the frame member 12 is joined, a damper member 14 having a damping function for absorbing the pressure generated during ink discharge is provided. Among the above-described components, the nozzle substrate 2, the flow path substrate 3, the piezoelectric element substrate 9, the holding substrate 10, etc. need to have a fine and complex pattern formed at a high density in order to obtain high image quality, so a single crystal silicon substrate is processed by semiconductor processing techniques (photolithography, etching, etc.). The frame member 12 is molded with a resin part (PPS, PPE, glass epoxy resin, etc.) in order to be made at a low cost without a complex pattern.

[0012] The processed and formed parts are positioned with high precision using optical alignment, positioning pins, etc., and then joined and fixed by an adhesive 5. Examples of the adhesive 5 used here include UV-curable adhesives, two-component room-temperature-curable adhesives, heat-curable adhesives, etc. However, since it comes into contact with ink, it is necessary to use an adhesive with high ink resistance. Therefore, a heat-curable adhesive may be used considering ink resistance and manufacturing tact time. However, due to the difference in the linear expansion rates of silicon and resin, which are the members to be adhered to each other, residual stress occurs as shown in Fig. 2, causing variations in the ejection speed within the head and resulting in a problem of deteriorated image quality.

[0013] Fig. 3 shows a cross-sectional view around the piezoelectric element substrate 9. The piezoelectric element substrate 9 has a structure in which the individual liquid chambers 6 are covered with a diaphragm 7 and a piezoelectric element 8 is disposed thereon. The piezoelectric element 8 is constituted by sandwiching a piezoelectric body 16 between a common electrode 17 which is an upper electrode and an individual electrode 15 which is a lower electrode. When compressive stress acts on the diaphragm 7, the diaphragm 7 becomes loose, so the piezoelectric element 8 is easily driven and the displacement amount of the piezoelectric element 8 increases. When tensile stress acts on the diaphragm 7, the diaphragm 7 becomes taut, so the piezoelectric element 8 is difficult to drive and the displacement amount of the piezoelectric element 8 decreases. Since there is a correlation between the displacement amount of the piezoelectric element 8 and the liquid ejection speed, the ejection speed changes according to the state of the stress acting on the diaphragm 7.

[0014] Fig. 4 shows a plan view of the main parts of the conventionally used nozzle substrate 2, flow path substrate 3, and frame member 12. In each of these members, the nozzle substrate 2 is provided with a nozzle arrangement region 1a which is an arrangement region of a plurality of nozzles 1. The nozzles 1 and the nozzle arrangement region 1a are provided over substantially the entire width of the nozzle substrate 2, and in Fig. 4, the illustration of the nozzles 1 and the nozzle arrangement region 1a in the central part is omitted. The frame member 12 is provided with a joining region 5a where the flow path substrate 3 is joined so that the common flow path 4 and the common flow path 11 are connected, that is, a region where the adhesive 5 is applied and spreads by wetting.

[0015] In the configuration shown in Figure 4, if the length of the nozzle arrangement area 1a is A (hereinafter also referred to as length A) and the length of the joining area 5a is B (hereinafter also referred to as length B), then the length B of the joining area 5a is configured to be shorter than the length A of the nozzle arrangement area 1a. In this specification, the size in the left-right direction shown in Figure 4 is described as "length," and the size in the up-down direction perpendicular to the "length" in Figure 4 is described as "width." In this configuration, there is a difference between length A and length B, and as described above, deformation occurs in the joining region 5a due to the difference in coefficient of thermal expansion. As a result, the position of nozzle 1 within the nozzle placement region 1a corresponding to the joining region 5a is greatly displaced, while the position of nozzle 1 positioned outside the joining region 5a is greatly displaced. This difference in displacement creates a stress difference, resulting in a difference in discharge velocity between the part of nozzle 1 near the end and the rest of the nozzle 1.

[0016] Figure 5 shows the variation in ejection speed (the value obtained by dividing the speed of each channel by the average speed of all channels) in the configuration shown in Figure 4. As is clear from Figure 5, the ejection speed is slow in the ejection channel corresponding to the bonding region 5a due to strong tensile stress, while the ejection channels near both ends, outside the bonding region 5a, are affected by less tensile stress, resulting in a relatively fast ejection speed distribution near both ends, indicated by reference numeral 19. Therefore, in the conventional configuration, there was a problem in that there was a large variation in the speed distribution of ejection speed between the central ejection channel and the ejection channels near both ends, which resulted in a decrease in image quality.

[0017] Figure 6 shows a conventional example in the configuration shown in Figure 4, in which the length A of the nozzle arrangement region 1a is kept unchanged, but the length B of the joining region 5a is made larger than length A, so that lengths A and B are almost the same, and common channels 4A and 11A that are longer than common channels 4 and 11 are provided. Figure 7 shows the variation in discharge speed in this configuration. In this configuration, although the variation in discharge speed is reduced compared to the configuration shown in Figure 4, the upward trend in the variation of discharge speed 19 near both ends remains large, as shown in Figure 7.

[0018] A first embodiment of the present invention that reduces the variability in the velocity distribution of the discharge velocity, which is one of the problems mentioned above, is described below. Figure 8 shows a plan view of the main parts of the nozzle substrate 20, flow path substrate 21, and frame member 22 according to the first embodiment of the present invention. The nozzle substrate 20 has a plurality of nozzles 1 formed on it, similar to the nozzle substrate 2, and a nozzle arrangement area 1a is provided. The flow path substrate 21 has two common flow paths 4, similar to those in Figure 4. Other flow paths in the flow path substrate 21 are not shown. Each member 20, 21, and 22 are used in place of each member 2, 3, and 12 in the inkjet head 18.

[0019] The frame member 22 is provided with two common channels 11, which serve as other common channels similar to those in Figure 4, and an opening 23 consisting of a through hole is provided in the center of the frame member 22 in the width direction. The frame member 22 is provided with a joining region 5a, similar to that of the frame member 12, that is, a region where the adhesive 5 is applied and a region where it spreads, and the length B of the joining region 5a is configured to be longer than the length A of the nozzle arrangement region 1a. In addition, the lengths C of the common channels 4 and 11 are configured to be shorter than their lengths A.

[0020] This configuration ensures that the tensile stress generated during the bonding and fixing of the adhesive 5 acts uniformly throughout the entire nozzle arrangement area 1a. As a result, variations in the ejection speed 19 near both ends can be suppressed, as shown in Figure 9. This provides an inkjet head 18 that can suppress variations in ejection speed within the nozzle arrangement area 1a and thus suppress a decrease in image quality. It is desirable that the distance between the end of the nozzle arrangement area 1a and the end of the bonding area 5a, i.e., the difference between length A and length B at both ends, be 1 mm or more. Furthermore, since length C is shorter than length A, the inkjet head 18 can be miniaturized.

[0021] Furthermore, since the frame member 22 has an opening 23 in the center, the tensile stress generated during adhesive fixing can be reduced, and variations in discharge speed within the nozzle arrangement region 1a can be further suppressed. Furthermore, in order to reduce the effect of stress on the diaphragm 7, it is desirable that the frame member 22, like the frame member 12, be configured not to be bonded to the holding substrate 10, as shown in Figure 1. This suppresses variations in ejection speed. If it is bonded to the holding substrate 10, variations in ejection speed can be suppressed by bonding over a wider (longer) area than the nozzle arrangement area 1a. Also, it is preferable that the flow path substrate 3 and the frame member 12 are joined outside the diaphragm 7 in the short-side direction of the inkjet head 18 as shown in Figure 1. This configuration reduces the effect of stress on the diaphragm 7 and suppresses variations in ejection speed.

[0022] Figure 10 shows a plan view of the main parts of the nozzle substrate 24, flow path substrate 25, and frame member 26 according to a second embodiment of the present invention. Multiple nozzles 1 are formed on the nozzle substrate 24 and a nozzle arrangement area 1a is provided. Two common flow paths 4A are provided on the flow path substrate 25, similar to those in Figure 6. Other flow paths in the flow path substrate 25 are not shown. Two common flow paths 11A are provided on the frame member 26, similar to those in Figure 6, and an opening 23 is provided in the center in the width direction. A joining area 5a is provided on the frame member 26, and the length B of the joining area 5a is configured to be longer than the length A of the nozzle arrangement area 1a. The lengths C of the common flow paths 4A and 11A are configured to be longer than the length A of the arrangement area 1a.

[0023] This configuration, similar to the first embodiment, allows the common channels 4 and 11 to be sealed with adhesive 5, thereby suppressing variations in the ejection speed 19 near both ends as shown in Figure 11. This provides an inkjet head 18 that can suppress variations in ejection speed within the nozzle arrangement area 1a and reduce the degradation of image quality. Furthermore, since length C is longer than length A, ink can be supplied evenly to all nozzles 1 within the nozzle arrangement area 1a, further uniformizing the ink ejection speed.

[0024] Figure 12 shows a third embodiment of the present invention. This third embodiment differs from the first embodiment shown in Figure 8 only in that it has an unbonded portion 5b in the bonding region 5a that is located outside the common channels 4 and 11 in the longitudinal direction, where adhesive 5 is not applied; all other configurations are the same. Note that channels other than the common channel 4 in the channel substrate 21 are not shown. This configuration allows the area in the bonding region 5a where the adhesive 5 is actually applied to be approximately the same as the nozzle arrangement region 1a, and a uniform tensile stress can be applied to the entire area of ​​the nozzle arrangement region 1a, thereby further suppressing variations in discharge speed.

[0025] Furthermore, in the third embodiment, since the width of the unbonded portion 5b is the same as the width of the common flow path 11, the area in the bonding region 5a where the adhesive 5 is actually applied can be brought even closer to the area of ​​the nozzle arrangement region 1a, and uniform tensile stress can be applied to the entire area of ​​the nozzle arrangement region 1a, thereby further suppressing variations in discharge speed. Furthermore, since the outer position of the unbonded portion 5b extends beyond the nozzle arrangement area 1a in the longitudinal direction (the length D between the two outer ends of the unbonded portion 5b is longer than the length A), the area in the bonding area 5a where the adhesive 5 is actually applied can be brought even closer to the area of ​​the nozzle arrangement area 1a, and uniform tensile stress can be applied to the entire area of ​​the nozzle arrangement area 1a, thereby further suppressing variations in discharge speed. Furthermore, since adhesive 5 is applied to the outer portion in the longitudinal direction of the unbonded portion 5b, the bonding region 5a forms a closed space surrounding the unbonded portion 5b, thereby reliably preventing ink leakage from the common channels 4 and 11.

[0026] Next, we will describe other liquid ejection devices equipped with an inkjet head 18. As shown in Figures 13 and 14, the printing apparatus 500, which is a liquid ejection device, includes an incoming means 501 for loading the continuous body 510, which is the recording medium, and a guiding and transporting means 503 for guiding and transporting the continuous body 510 loaded by the incoming means 501 toward the printing means 505. The printing apparatus 500 also includes a printing means 505 that performs a printing operation to form an image by ejecting droplets onto the continuous body 510, a drying means 507 for drying the continuous body 510 to which the droplets have adhered, and an outgoing means 509 for outgoing the continuous body 510. The continuous material 510 is fed out from the main winding roller 511 of the loading means 501, guided and transported by rollers of the loading means 501, the guiding and transporting means 503, the drying means 507, and the unloading means 509, and then wound onto the winding roller 591 of the unloading means 509. In the printing means 505, the continuous material 510 is transported on the transport guide member 559, facing the head unit 550, which is a liquid discharge unit, and an image is printed by droplets discharged from the head unit 550.

[0027] The printing apparatus 500 is equipped with a head unit 550 and liquid ejection units 100A and 100B, each of which is mounted on a common base member 552. Each liquid ejection unit 100A and 100B ejects droplets of the same color using the head row 100A1 and 100A2 of liquid ejection unit 100A, when the direction of alignment of the inkjet heads 18 in a direction perpendicular to the continuum transport direction is defined as the head array direction. Similarly, the head row 100B1 and 100B2 of liquid ejection unit 100A, the head row 100C1 and 100C2 of liquid ejection unit 100B, and the head row 100D1 and 100D2 of liquid ejection unit 100B ejects liquid of the desired color, respectively.

[0028] Next, yet another example of a printing apparatus which is a liquid dispensing device according to the present invention will be described with reference to Figures 15 and 16. The printing apparatus 400, as a liquid ejection device, is a serial type printing apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is stretched across the left and right side plates 491A and 491B, and holds the carriage 403 in a movable position. The carriage 403 reciprocates in the main scanning direction by receiving the driving force of the main scanning motor 405 via the timing belt 408 stretched between the drive pulley 406 and the driven pulley 407.

[0029] The carriage 403 is equipped with a liquid ejection unit 440 which integrally includes an inkjet head 18 and a head tank 441. Here, the inkjet head 18 ejects liquids of various colors, such as yellow (Y), cyan (C), magenta (M), and black (K). The inkjet head 18 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and with the liquid ejection direction facing downwards. The inkjet head 18 is connected to a liquid circulation device (not shown), and the desired color liquid is circulated and supplied to the inkjet head 18.

[0030] The printing apparatus 400 is equipped with a transport mechanism 495 for transporting the paper 410, which is the recording medium. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 that drives the transport belt 412. The transport belt 412, which is an endless belt, is stretched between a transport roller 413 and a tension roller 414, and is used to pick up the paper 410 and transport it to a position facing the inkjet head 18. Pickup is performed by electrostatic attraction or air suction, etc. The transport belt 412 is moved circumferentially in the sub-scanning direction by the driving force of the sub-scanning motor 416 being transmitted via a timing belt 417 and a timing pulley 418.

[0031] A maintenance and recovery mechanism 420 for maintaining and restoring the inkjet head 18 is positioned on one side of the carriage 403 in the main scanning direction, and to the side of the transport belt 412. The maintenance and recovery mechanism 420 consists of, for example, a cap member 421 for capping the nozzle surface of the inkjet head 18, and a wiper member 422 for wiping the nozzle surface. The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the transport mechanism 495 are mounted on a housing that includes side plates 491A, 491B, and a back plate 491C. In the printing apparatus 400 with the above configuration, the paper 410 is held in place by the transport belt 412, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412. At this time, the inkjet head 18 is driven according to the image signal while the carriage 403 is moved in the main scanning direction, thereby ejecting liquid onto the stationary paper 410 to form an image.

[0032] Next, the liquid dispensing unit 440 described above will be explained based on Figure 17. The liquid ejection unit 440 is composed of a housing portion consisting of side plates 491A, 491B and a back plate 491C, which are components of the printing device 400, which is a liquid ejection device, as well as the main scanning movement mechanism 493, carriage 403, inkjet head 18, etc. Furthermore, it is also possible to configure a liquid dispensing unit in which the maintenance and recovery mechanism 420 described above is further attached to, for example, the side plate 491B of the liquid dispensing unit 440.

[0033] Next, another example of a liquid dispensing unit according to one embodiment of the present invention will be described with reference to Figure 18. The liquid ejection unit 450 shown in Figure 18 includes an inkjet head 18 to which a flow channel component 444 is attached, and a tube 456 connected to the flow channel component 444. The flow channel component 444 is located inside a cover 442, and a connector 443 for electrical connection to the inkjet head 18 is provided on the upper part of the flow channel component 444. A configuration including a head tank 441 instead of the flow channel component 444 is also possible. In the liquid ejection units 100A, 100B, 440, 450, 550, and the printing devices 400, 500, which are liquid ejection devices, the same effects and benefits as those of the inkjet head 18 described above can be obtained.

[0034] In the present invention, the liquid used can be any liquid having viscosity and surface tension that allows it to be discharged from a liquid discharge head, and its properties are not particularly limited, however, it is preferable that its viscosity becomes 30 mPa·s or less at room temperature and atmospheric pressure, or upon heating and cooling. More specifically, this includes solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functional materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium, edible materials such as natural pigments, and solutions, suspensions, and emulsions containing these. These can be used, for example, in inkjet inks, surface treatment liquids, and three-dimensional molding material liquids. The energy source for discharging liquid includes piezoelectric actuators (multilayer piezoelectric elements and thin-film piezoelectric elements), thermal actuators using electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a diaphragm and a counter electrode.

[0035] The "liquid discharge head" is not limited to any particular pressure generating means. For example, in addition to the piezoelectric actuator described above (which may use a multilayer piezoelectric element), it may also use a thermal actuator that uses an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a diaphragm and a counter electrode. A "liquid discharge unit" is a liquid discharge head with integrated functional components and mechanisms, and includes an assembly of parts related to liquid discharge. For example, a "liquid discharge unit" may include a combination of a liquid discharge head with at least one of the following components: a head tank, carriage, supply mechanism, maintenance and recovery mechanism, main scanning movement mechanism, and liquid circulation device. Here, integration includes, for example, cases where a liquid dispensing head and functional components or mechanisms are fixed to each other by fastening, bonding, engaging, etc., or where one is held movably relative to the other. Furthermore, the liquid dispensing head and functional components or mechanisms may be detachable from each other.

[0036] Liquid dispensing units can be configured with an integrated liquid dispensing head and head tank, or with the two integrated by being connected to each other via tubing or similar means. It is also possible to add a unit containing a filter between the liquid dispensing head and head tank of these liquid dispensing units. Furthermore, liquid dispensing units include those in which the liquid dispensing head and carriage are integrated, and those in which the liquid dispensing head, carriage, and main scanning movement mechanism are integrated. Additionally, some liquid dispensing units have the liquid dispensing head movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid dispensing head and scanning movement mechanism are integrated.

[0037] Some liquid discharge units integrate the liquid discharge head, carriage, and maintenance / recovery mechanism by fixing a cap component, which is part of the maintenance / recovery mechanism, to a carriage to which the liquid discharge head is attached. Other liquid discharge units integrate the liquid discharge head and supply mechanism by connecting a tube to a liquid discharge head to which a head tank or flow path component is attached. Liquid from a liquid storage source is supplied to the liquid discharge head via this tube. The main scanning movement mechanism shall include the guide member alone. The supply mechanism shall include the tube alone and the loading section alone.

[0038] In this invention, the liquid discharge unit is described in combination with a liquid discharge head, but the liquid discharge unit also includes a head module that includes the liquid discharge head described above, and a head unit in which the functional components and mechanisms described above are integrated. Liquid dispensing devices include those that drive the liquid dispensing head to dispense liquid, and are equipped with a liquid dispensing head, liquid dispensing unit, head module, head unit, etc. Liquid dispensing devices include not only those that can dispense liquid onto surfaces to which liquid can adhere, but also those that dispense liquid into gases or liquids.

[0039] The liquid dispensing device may also include means for feeding, conveying, and dispensing paper onto materials to which liquid can adhere, as well as other pre-treatment and post-treatment devices. Examples of liquid ejection devices include image forming devices that eject ink to form an image on a recording medium, and three-dimensional molding devices that eject molding liquid onto a powder layer formed in layers to create three-dimensional objects. Furthermore, liquid dispensing devices are not limited to those that visualize meaningful images such as letters or figures through the dispensed liquid. For example, they also include devices that form patterns that do not have meaning in themselves, or devices that create three-dimensional images.

[0040] The above-mentioned objects to which liquids can adhere refer to objects to which liquids can adhere, at least temporarily, including those that adhere and solidify or adhere and penetrate. Specific examples include recording media such as paper, film, and cloth; electronic components such as electronic circuit boards and piezoelectric elements; powder layers; organ models; and inspection cells. Unless otherwise specified, it includes all objects to which liquids can adhere. The material to which the liquid can adhere may be any material, such as paper, thread, fibers, fabric, leather, metal, plastic, glass, wood, or ceramics, as long as the liquid can adhere to it, even temporarily.

[0041] A liquid dispensing device includes a configuration in which a liquid dispensing head and an object to which the liquid can adhere move relative to each other, but the object that moves is not limited to either one or the other. Specific examples include serial type devices in which the liquid dispensing head moves, and line type devices in which the liquid dispensing head does not move. Other examples of liquid dispensing devices include processing liquid coating devices that dispense processing liquid onto the surface of paper for purposes such as modifying the surface of the paper, and injection granulation devices that granulate fine particles of raw materials by spraying a composition liquid, in which raw materials are dispersed in a solution, through a nozzle.

[0042] The liquid dispensing apparatus of the present invention also includes apparatus for manufacturing electrodes and electrochemical elements. The electrode manufacturing apparatus will be described below. Figure 19 is a schematic diagram showing an example of an electrode manufacturing apparatus according to one embodiment of the present invention. The electrode manufacturing apparatus 700 is an apparatus for manufacturing an electrode including a layer having electrode material by discharging a liquid composition using a liquid discharging unit including a liquid discharging head. First, the means and process for forming the layer containing the electrode material will be described. The liquid discharge means provided in the electrode manufacturing apparatus 700 shown in Figure 38 is the liquid discharge unit of the present invention described above. A liquid composition is discharged from the liquid discharge head of the liquid discharge unit, thereby applying the liquid composition to the target object and forming a liquid composition layer. The target object (hereinafter sometimes referred to as the "discharge target object") is not particularly limited as long as it is an object on which a layer containing electrode material is formed, and can be appropriately selected according to the purpose. For example, the target object may be an electrode substrate (current collector), an active material layer, a layer containing solid electrode material, etc. The target object may also be an electrode composite layer containing active material on an electrode substrate. Furthermore, the discharge means and discharge process may be means and processes for forming a layer containing electrode material by directly discharging the liquid composition, as long as it is possible to form a layer containing electrode material on the discharge target object. Moreover, the discharge means and discharge process may be means and processes for forming a layer containing electrode material by indirectly discharging the liquid composition.

[0043] Next, we will describe the other components and processes. Other components included in the electrode composite layer manufacturing apparatus are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected according to the purpose. Similarly, other steps included in the electrode composite layer manufacturing method are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected according to the purpose. For example, components and steps included in the electrode composite layer manufacturing apparatus and manufacturing method include heating means and heating steps.

[0044] Next, the heating means and heating process will be described. The heating means included in the electrode composite layer manufacturing apparatus is a means for heating the liquid composition discharged by the discharge means. Furthermore, the heating step included in the electrode composite layer manufacturing method is a step for heating the liquid composition discharged in the discharge step. By heating the liquid composition, it can be dried.

[0045] Next, a configuration for forming a layer containing electrode material by direct discharge of a liquid composition will be described. Here, as an example of an electrode manufacturing apparatus that forms a layer containing electrode material, an electrode manufacturing apparatus that forms an electrode composite layer containing active material on an electrode substrate (current collector) will be described. As shown in Figure 38, the electrode manufacturing apparatus 700 includes a discharge process section 110 which includes a step of applying a liquid composition onto a printing substrate 704 having an object to be discharged to form a liquid composition layer, and a heating process section 130 which includes a heating step of heating the liquid composition to obtain an electrode composite layer.

[0046] The electrode manufacturing apparatus 700 is equipped with a transport means 705 for transporting the printing substrate 704, and the transport means 705 transports the printing substrate 704 at a preset speed in the order of the discharge process section 110 and the heating process section 130. There are no particular restrictions on the method for manufacturing the printing substrate 704 having an object to be discharged, such as an active material layer, and well-known methods can be appropriately selected. The discharge process section 110 is equipped with a liquid discharge head 281a for realizing a liquid composition application process for applying a liquid composition onto the printing substrate 704, a storage container 281b for containing the liquid composition 707, a supply tube 281c for supplying the liquid composition 707 in the storage container 281b to the liquid discharge head 281a, and the like.

[0047] In the discharge process section 110, the liquid composition 707 is discharged from the liquid discharge head 281a, and the liquid composition 707 is applied to the printing substrate 704 to form a thin film layer of the liquid composition. The containment container 281b may be integrated with the electrode composite layer manufacturing apparatus, or it may be detachable from the electrode composite layer manufacturing apparatus. Alternatively, the containment container 281b may be a container used for adding to a containment container integrated with the electrode composite layer manufacturing apparatus, or a containment container detachable from the electrode composite layer manufacturing apparatus. The containment container 281b and the supply tube 281c can be arbitrarily selected as long as they are capable of stably containing and supplying the liquid composition 707.

[0048] In the heating section 130, a solvent removal step is performed to remove any solvent remaining in the liquid composition layer by heating. Specifically, the solvent remaining in the liquid composition layer is removed from the liquid composition layer by drying it with heating by the heating device 703 provided in the heating section 130, thereby forming the electrode composite layer. Furthermore, the solvent removal step in the heating section 130 may be performed under reduced pressure. There are no particular restrictions on the heating device 703, and it can be appropriately selected according to the purpose. For example, the heating device 703 can be a substrate heater, an IR heater, a hot air heater, etc. The heating device 703 may also be a combination of at least two of the substrate heater, IR heater, and hot air heater. The heating temperature and heating time can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the film thickness to be formed.

[0049] In the electrode manufacturing apparatus 700, the same type as the inkjet head 18 described above is used as the liquid ejection head 281a. By using the electrode manufacturing apparatus 700 according to an embodiment of the present invention, a liquid composition can be discharged to a target position on the object to be discharged. The electrode mixture layer can be suitably used, for example, as part of the configuration of an electrochemical element. There are no particular restrictions on the components of the electrochemical element other than the electrode mixture layer, and well-known components can be appropriately selected. Examples of components other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, etc.

[0050] Examples of the present invention are as follows: [1] A liquid discharge head comprising: a nozzle substrate having a nozzle arrangement region on which a plurality of nozzles for discharging liquid are arranged; a flow path substrate having a common flow path communicating with the nozzles; a piezoelectric element substrate having individual flow paths communicating with the nozzles; a diaphragm formed to cover the individual flow path; and a piezoelectric element provided in the individual flow path; a holding substrate having a recess in the vibration region of the piezoelectric element; and a frame member having another supply flow path communicating with the common flow path, wherein the size of the flow path substrate in the short direction is larger than the size of the piezoelectric element substrate and the holding substrate in the short direction; the flow path substrate and the frame member are joined in the short direction on the outside of the piezoelectric element substrate and the holding substrate either directly or via a member thinner than the piezoelectric element substrate; the common flow path and the other common flow path are joined to each other by adhesive; and the length of the joining region between the common flow path and the other common flow path is longer than the length of the nozzle arrangement region. [2] The liquid discharge head according to [1], characterized in that the length of the common channel and the other common channels is shorter than the length of the nozzle arrangement area. [3] The liquid discharge head according to [1], characterized in that the length of the common channel and the other common channels is longer than the length of the nozzle arrangement area. [4] The liquid discharge head according to any one of [1] to [3], characterized in that the bonding region includes an unbonded portion outside the common channel and the other common channel to which adhesive is not applied. [5] The liquid discharge head according to [4] is characterized in that the unglued portion has the same width as the common channel and the other common channels. [6] The liquid discharge head according to [4] or [5], characterized in that the unadhesive portion extends beyond the nozzle arrangement area. [7] A liquid dispensing head according to any one of [4] to [6], characterized in that an adhesive is applied to the outer part of the unadhesive portion. [8] A liquid dispensing head according to any one of [1] to [7], characterized in that the frame member and the holding substrate are not directly joined. [9] The liquid dispensing head according to any one of [1] to [8], characterized in that the frame member has an opening consisting of a through hole. A liquid dispensing unit characterized by having a liquid dispensing head as described in any one of

[10] [1] to [9]. A liquid dispensing device characterized by having a liquid dispensing head as described in any one of

[11] [1] to [9]. This is a liquid dispensing device characterized by having the liquid dispensing unit described in

[12]

[10] .

[0051] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the spirit of the invention as described in the claims, unless otherwise specifically limited in the above description. The effects described in the embodiments of the present invention are merely illustrative of the most preferred effects that may arise from the present invention, and the effects of the present invention are not limited to those described in the embodiments. [Explanation of symbols]

[0052] 1 nozzle 1a Nozzle placement area 4,4A Common channel 5. Adhesive 5a Junction area 5b Unbonded part 7 Vibration plate 8 Piezoelectric elements 9. Piezoelectric element substrate 10 Holding board 11,11A Other common channels (common channels) 13 Individual channel 18. Liquid ejection head (inkjet head) 20,24 Nozzle substrate 21,25 Flow channel substrate 22,26 Frame members 23 Opening 100, 100A, 100B, 440, 450, 550 Liquid Dispensing Unit 400,500 Liquid discharge device (printing device) 700 Liquid discharge device (electrode manufacturing device) [Prior art documents] [Patent Documents]

[0053] [Patent Document 1] Japanese Patent Publication No. 2018-51768

Claims

1. A nozzle substrate having a nozzle arrangement region in which multiple nozzles for discharging liquid are arranged, A channel substrate having a common channel that communicates with the nozzle, A piezoelectric element substrate having individual channels communicating with the nozzle, a diaphragm formed to cover the individual channels, and piezoelectric elements provided in the individual channels, A holding substrate having a recess in the vibration region of the piezoelectric element, A frame member having another supply channel that communicates with the aforementioned common channel, Equipped with, The size of the flow channel substrate in the short direction is larger than the size of the piezoelectric element substrate and the holding substrate in the short direction. The flow channel substrate and the frame member are joined in the short direction either directly outside the piezoelectric element substrate and the holding substrate, or via a member thinner than the piezoelectric element substrate. The common channel and the other common channel are joined to each other by an adhesive, and the length of the joining region between the common channel and the other common channel is longer than the length of the nozzle arrangement region in the liquid discharge head.

2. In the liquid dispensing head according to claim 1, A liquid discharge head characterized in that the length of the common channel and the other common channel are shorter than the length of the nozzle arrangement area.

3. In the liquid dispensing head according to claim 1, A liquid discharge head characterized in that the length of the common channel and the other common channel are longer than the length of the nozzle arrangement area.

4. In the liquid dispensing head according to claim 1, The liquid dispensing head is characterized in that the bonding region includes an unbonded portion outside the common channel and the other common channel, where no adhesive is applied.

5. In the liquid dispensing head according to claim 4, The liquid discharge head is characterized in that the unglued portion has the same width as the common channel and the other common channels.

6. In the liquid dispensing head according to claim 4, A liquid dispensing head characterized in that the unglued portion extends beyond the nozzle arrangement area.

7. In the liquid dispensing head according to claim 4, A liquid dispensing head characterized in that adhesive is applied to the outer portion of the unglued area.

8. In the liquid dispensing head according to claim 1, A liquid dispensing head characterized in that the frame member and the holding substrate are not directly joined.

9. In the liquid dispensing head according to claim 1, The liquid dispensing head is characterized by having an opening consisting of a through hole in the frame member.

10. A liquid dispensing unit characterized by having a liquid dispensing head according to any one of claims 1 to 9.

11. A liquid dispensing device characterized by having a liquid dispensing head according to any one of claims 1 to 9.

12. A liquid dispensing device characterized by having the liquid dispensing unit described in claim 10.

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