LIQUID EJECTION HEAD, LIQUID EJECTION UNIT, AND DEVICE FOR EJECTION OF LIQUID

Abstract

To provide a liquid discharge head which reduces fluctuation of discharge performance of a liquid.SOLUTION: A liquid discharge head 300a includes a piezoelectric element 12 which pressurizes a liquid, a holding substrate 50 which holds the piezoelectric element 12, a nozzle plate 1 which has a plurality of nozzles 4 for discharging the liquid an is joined to the holding substrate 50, and a frame 70a which is joined to the holding substrate 50 through an adhesive 90 on a surface opposite to a surface of the holding substrate 50, where the nozzle plate 1 is joined. The frame 70a includes at least one boss 71a in a protruded shape on a joined surface to the holding substrate 50. The boss 71a is arranged in a position where the boss does not overlap with the piezoelectric element 12 when the boss 71a is projected in a liquid discharge direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, a liquid ejection unit, and an apparatus for ejecting liquid. [Background technology]

[0002] A known example of a liquid ejection head is one in which a holding member covering the piezoelectric elements is bonded to an actuator member on which multiple piezoelectric elements are arranged, and the holding member is bonded with adhesive to a frame that forms a common liquid chamber that supplies liquid to the individual liquid chambers. However, in a liquid ejection head, if foreign matter is trapped during bonding with an adhesive, strong pressure is applied locally, causing deformation of the piezoelectric element and its surrounding structure, which has a problem of affecting the liquid ejection performance. For example, Patent Documents 1 and 2 disclose a technique for joining two components using an adhesive, but do not address the effect that the inclusion of foreign matter has on the ejection performance of the piezoelectric element, and there is room for improvement. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection head that reduces fluctuations in liquid ejection performance. [Means for solving the problem]

[0004] In order to solve the above-mentioned problems, the liquid ejection head of the present invention comprises: a piezoelectric element that pressurizes the liquid; a holding substrate for holding the piezoelectric element; a nozzle plate having a plurality of nozzles for ejecting liquid and bonded to the holding substrate; a frame bonded to the holding substrate via an adhesive on a surface of the holding substrate opposite to a surface to which the nozzle plate is bonded; the frame has at least one convex shape on a surface to be bonded to the holding substrate, The convex shape is disposed at a position where it does not overlap with the piezoelectric element when the convex shape is projected in the liquid ejection direction. 、 The holding substrate has a damper and includes a substrate that supports the piezoelectric element and a substrate that holds the damper. It shall be. [Effects of the Invention]

[0005] According to the present invention, it is possible to provide a liquid ejection head that reduces fluctuations in liquid ejection performance. [Brief explanation of the drawings]

[0006] [Figure 1] 1A and 1B are diagrams illustrating an outline of a configuration example of a liquid ejection head according to an embodiment. [Figure 2] 1A and 1B are diagrams illustrating an example of the configuration of a liquid ejection head according to a first embodiment. [Figure 3] 3A and 3B are diagrams illustrating a cross section of the liquid ejection head of FIG. 2, where FIG. 3A is a cross section taken along line IIIA-IIIA in FIG. 2, and FIG. 3B is a cross section taken along line IIIB-IIIB in FIG. [Figure 4] 10A and 10B are diagrams illustrating an example of the configuration of a liquid ejection head according to a second embodiment. [Figure 5] 5A and 5B are diagrams illustrating a cross section of the liquid ejection head of FIG. 4, where FIG. 5A is a cross section taken along line VA-VA in FIG. 4, and FIG. 5B is a cross section taken along line VB-VB in FIG. [Figure 6] 1A and 1B are diagrams illustrating an example of the configuration of a liquid ejection head according to Comparative Example 1. [Figure 7] 7A and 7B are diagrams illustrating a cross section of the liquid ejection head of FIG. 6, where (A) is a cross section taken along line VIIA-VIIA in FIG. 6, and (B) is a cross section taken along line VIIB-VIIB in FIG. [Figure 8] 10A and 10B are diagrams illustrating an example of the configuration of a liquid ejection head according to Comparative Example 2. [Figure 9] 9A and 9B are diagrams illustrating a cross section of the liquid ejection head of FIG. 8, where (A) is a cross section taken along line IXA-IXA of FIG. 8, and (B) is a cross section taken along line IXB-IXB of FIG. [Figure 10]10 is a table illustrating the incidence of a decrease in Vj due to the pinching of a foreign object. [Figure 11] 10A and 10B are diagrams illustrating the effect of suppressing a decrease in Vj by a boss. [Figure 12] 1 is a cross-sectional explanatory view taken along the short side direction of a head of an example of a head module using a liquid ejection head according to the present invention. [Figure 13] FIG. 2 is an exploded perspective view of the head module. [Figure 14] FIG. 2 is an exploded perspective view of the base member, the head, and the cover member. [Figure 15] FIG. 2 is an exploded perspective view of the head module as viewed from the nozzle surface side. [Figure 16] 1 is a schematic explanatory diagram of an example of a liquid ejection device according to the present invention. [Figure 17] FIG. 2 is a plan view illustrating an example of a head unit of the device. [Figure 18] FIG. 10 is an explanatory plan view of the main parts of another example of a printing device as a liquid ejecting device according to the present invention. [Figure 19] FIG. [Figure 20] FIG. 10 is a plan view illustrating a main part of another example of a liquid ejection unit according to the present invention. [Figure 21] FIG. 10 is a front view illustrating still another example of a liquid discharge unit according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings for explaining the embodiments of the present invention, components such as members and components having the same function or shape are designated by the same reference numerals as far as they can be distinguished, and descriptions thereof will be omitted once they have been described.

[0008] FIG. 1 is a diagram illustrating an outline of an example of the configuration of a liquid ejection head according to an embodiment. The liquid ejection head 300 includes a nozzle plate 1 having a plurality of nozzles, a holding substrate 50 that holds the piezoelectric elements, and a frame 70 that is bonded to the holding substrate 50 via an adhesive. The nozzle plate 1 is bonded to the holding substrate 50, and the frame 70 is bonded to the surface of the holding substrate 50 opposite to the surface to which the nozzle plate 1 is bonded. The liquid ejection head 300 has a frame 70 as an upper layer of a holding substrate 50 . Each embodiment will be described below.

[0009] Embodiment 1. Fig. 2 is a diagram illustrating an example of the configuration of the liquid ejection head of embodiment 1. Fig. 2 is a diagram of the liquid ejection head 300a as seen from above (the frame 70a side), and shows the arrangement of the common liquid chamber 10, the piezoelectric element 12, and the boss 71a having a convex shape in a see-through manner. 3A and 3B are diagrams illustrating a cross section of the liquid ejection head of FIG. 2, where (A) is a cross section taken along line IIIA-IIIA of FIG. 2, and (B) is a cross section taken along line IIIB-IIIB of FIG. 2.

[0010] The holding substrate 50 has, for example, a liquid chamber member 51 that forms the individual liquid chambers 6 that communicate with the nozzles 4, an actuator member 53 that is joined to the liquid chamber member 51 on the side opposite the nozzle plate 1 and on which piezoelectric elements 12 are arranged, and a holding member 55 that has recesses formed therein to accommodate the piezoelectric elements 12. A detailed description will be omitted here.

[0011] The frame 70 has a common liquid chamber 10 that supplies liquid to the individual liquid chambers 6, and an opening 16 that supplies liquid to the common liquid chamber 10. The frame 70 has bosses 71 a formed on the joining surface that joins with the holding substrate 50 , and is joined to the holding substrate 50 with adhesive 90 . The boss 71a is disposed at a position that does not overlap with the piezoelectric element 12 when the boss 71a is projected in the liquid ejection direction. The boss 71a may have, for example, a rectangular shape with filleted corners on the surface facing the holding substrate 50. An example of the shape of the facing surface is shown enlarged on the right side of Fig. 2.

[0012] The surface of the frame 70a facing the boss 71a comes into contact with the holding substrate 50 via the adhesive 90. In this way, the distance between the surface of the boss 71a facing the holding substrate 50 is shorter than the distance between the holding substrate 50 and the surface of the joining surface on which the boss 71a is not provided, and the adhesive 90 interposed between the surface on which the boss 71a is not provided and the holding substrate 50 is thicker than in the portion on which the boss 71a is provided. This makes it possible to reduce the contact area between the surface of the boss 71a facing the holding substrate 50 and the holding substrate 50. In this way, by providing a gap between the frame 70a and the holding substrate 50 using the boss 71a, the liquid ejection head 300a can reduce deformation of the piezoelectric element 12 due to the inclusion of foreign matter, and reduce fluctuations in liquid ejection performance.

[0013] The frame 70a is configured so that the boss 71a is not disposed on the portion of the bonding surface located above the piezoelectric element 12. In this way, deformation of the piezoelectric element 12 when a foreign object is trapped can be suppressed, and deformation of the piezoelectric element 12 due to the boss 71a can be prevented.

[0014] The bosses 71a are preferably disposed at least at the four corners of the rectangular frame 70a, so that warping and deformation of the holding substrate 50 can be suppressed.

[0015] Furthermore, the holding substrate 50 may have a damper 57 that dissipates vibration energy to reduce the amplitude of the shock or vibration. The holding substrate 50 may have, for example, a piezoelectric element holding substrate that holds the actuator member 53 on which the piezoelectric element 12 is arranged, and a damper holding substrate that holds the damper 57. In this way, it is possible to reduce the transmission of vibrations generated by the piezoelectric element 12 to the frame 70a. Although Figure 3 shows an example of a configuration in which the holding member 55 has a damper 57, the holding substrate 50 may not have a damper 57, and this can have the effect of suppressing deformation of the piezoelectric element 12 caused by the boss 71a.

[0016] Embodiment 2. Fig. 4 is a diagram illustrating an example of the configuration of a liquid ejection head according to embodiment 2. Fig. 4 is a diagram illustrating a liquid ejection head 300b as seen from above, and shows the arrangement of the common liquid chamber 10, the piezoelectric element 12, and the boss 71b in a see-through manner. 5A and 5B are diagrams illustrating a cross section of the liquid ejection head of FIG. 4, where (A) is a cross section taken along line VA-VA in FIG. 4, and (B) is a cross section taken along line VB-VB in FIG. 4.

[0017] The second embodiment differs from the first embodiment in that the opposing surfaces of the bosses 71b are circular, and a plurality of bosses are provided in addition to the four corners of the frame 70b. The bosses 71b may be arranged at any interval (for example, at equal intervals) from the four corners of the frame 70b along at least two sides toward the center. By providing multiple bosses 71b at locations other than the four corners, warping and deformation of the entire holding substrate can be suppressed, thereby suppressing deformation of the piezoelectric element. Furthermore, even if the rigidity of the holding substrate 50 is low, deformation of the holding substrate can be suppressed.

[0018] Other embodiments. In the following description, when there is no need to distinguish between the frames 70a, 70b or the bosses 71a, 71b, they will be referred to as the frame 70 or the boss 71. In each of the above embodiments, it is preferable that the holding substrate 50 does not have a groove formed on the surface opposite to the surface that comes into contact with the boss 71. In this way, deformation of the holding substrate 50 by the boss 71 can be prevented.

[0019] The height of the boss 71 should be set to a minimum value so that it is larger than the expected size of foreign matter and can be used with a low-viscosity adhesive. For example, the height of the boss 71 should be set to 20 to 100 micrometers (μm).

[0020] Furthermore, it is preferable that the opposing surface of the boss 71 has a circular shape such as a circle or an ellipse, or if it is a polygon, the corners are filleted, which can prevent damage to the holding substrate 50 and stress concentration.

[0021] In each of the above embodiments, a configuration example in which a boss 71 is provided on the frame 70 has been described, but a boss having a convex shape on the holding substrate side may also be provided on the holding substrate 50 (on the joining surface where the holding substrate 50 is joined to the frame). Furthermore, bosses may be provided on both the frame 70 and the holding substrate 50. When bosses are provided on both, it is preferable that the bosses are arranged so that they do not come into contact with each other and are not arranged above the piezoelectric elements. A plurality of bosses may be arranged on the frame 70 and the holding substrate 50, alternating at any intervals (or according to a predetermined rule, such as alternating two at a time) from the four corners of the frame 70 along at least two sides toward the center.

[0022] <Evaluation results> Below, we will explain the results of evaluating the fluctuations in liquid ejection performance for the liquid ejection heads of Embodiments 1 and 2 using Comparative Examples 1 and 2. The liquid ejection performance is evaluated using the velocity Vj at which the liquid ejection head ejects liquid from the nozzles. Hereinafter, "velocity Vj" may also be referred to as "Vj".

[0023] First, a comparative example will be described. Comparative Example 1 Fig. 6 is a diagram illustrating an example of the configuration of a liquid ejection head of Comparative Example 1. Fig. 6 is a diagram illustrating a liquid ejection head 300p1 as seen from above, and similarly to Figs. 2 and 4, shows the arrangement of piezoelectric elements 12 and the like in a see-through manner. 7A and 7B are diagrams illustrating a cross section of the liquid ejection head of FIG. 6, where (A) is a cross section taken along line VIIA-VIIA of FIG. 6, and (B) is a cross section taken along line VIIB-VIIB of FIG. 6. The liquid ejection head 300p1 of Comparative Example 1 is similar to that of the first embodiment, except that the frame 70p1 is not provided with the boss 71.

[0024] Comparative Example 2 Fig. 8 is a diagram illustrating an example of the configuration of a liquid ejection head of Comparative Example 2. Fig. 8 is a diagram illustrating a liquid ejection head 300p2 as seen from above, and similarly to Figs. 2 and 4, shows the arrangement of piezoelectric elements 12 and the like in a see-through manner. 9A and 9B are diagrams illustrating a cross section of the liquid ejection head of FIG. 8, where (A) is a cross section taken along line IXA-IXA of FIG. 8, and (B) is a cross section taken along line IXB-IXB of FIG. The liquid ejection head 300p2 of Comparative Example 2 is the same as that of Embodiment 2, except that the arrangement of the bosses 71b on the bonding surface of the frame 70p2 is changed. More specifically, the liquid ejection head 300p2 has the same number of bosses 71b as that of Embodiment 2, and four of the bosses 71b that are arranged are moved and arranged above the piezoelectric elements 12.

[0025] Using the liquid ejection heads of embodiments 1 and 2 and comparative examples 1 and 2, the frame and holding substrate were joined using an adhesive, and the incidence of Vj decrease due to foreign matter being trapped between the frame and holding substrate and the effect of the boss in suppressing Vj decrease were evaluated. FIG. 10 is a table illustrating the incidence of Vj reduction due to pinched foreign objects. FIG. 11 is a diagram illustrating the effect of suppressing a decrease in Vj by the boss.

[0026] In FIG. 10, N is the number of liquid ejection heads, which was set to 30. The Vj drop occurrence rate [%] due to foreign object entrapment indicates the percentage of heads in which a Vj drop occurred out of 30 heads.

[0027] As shown in FIG. 10, the incidence of Vj reduction due to pinched foreign matter was smaller in the first and second embodiments and the second comparative example, in which the bosses were provided, than in the first comparative example. This is because the boss creates a gap between the frame and the holding substrate, which prevents deformation of the piezoelectric element even if a foreign object is caught in it.

[0028] Figure 11 shows the change in velocity Vj when liquid is ejected from a nozzle at a voltage of 7 mV using a liquid ejection head with and without a foreign object trapped inside. The vertical axis of each graph represents velocity Vj [m / s], and the horizontal axis represents channel (ch). Here, a liquid ejection head with 400 channels is used, and the position of each channel is indicated as 0 (zero) to 400.

[0029] As shown in FIG. 11, in the first and second embodiments in which the frame has a boss and the piezoelectric element does not have a boss, the change in velocity Vj between channels is small regardless of whether a foreign object is sandwiched or not. On the other hand, in Comparative Example 1, which did not have a boss, a decrease in speed Vj occurred due to the presence of a foreign object. Also, in Comparative Example 2, in which a boss was placed on the piezoelectric element, a decrease in speed Vj occurred regardless of whether a foreign object was trapped. In FIG. 11, dashed circles indicate the location where the foreign object was caught (Comparative Example 1) and the position of the boss (Comparative Example 2).

[0030] In embodiments 1 and 2, a sufficient gap is provided between the frame and the holding substrate by adhesive, and even if a foreign object is sandwiched between the frame and the holding substrate, no local pressure is applied to the holding substrate, so there is no decrease in speed Vj. In Comparative Example 1, since the frame had no boss, the foreign matter locally applied pressure to the holding substrate, causing the piezoelectric element to deform, resulting in a decrease in the speed Vj. In Comparative Example 2, although there was no decrease in the speed Vj due to the pinching of foreign matter, the boss applied pressure locally to the holding substrate, so the speed Vj decreased.

[0031] From the above results, it can be said that the configurations of embodiments 1 and 2 are superior in terms of the incidence of Vj drops due to foreign matter entrapment and in terms of suppressing Vj drops.

[0032] An example of the configuration of a head module (also referred to as a "liquid ejection unit") using a liquid ejection head that can employ the above-described features of the present invention will be described below. Fig. 12 is a cross-sectional explanatory diagram along the short side of the head of an example of a head module that uses a liquid ejection head according to the present invention, Fig. 11 is an exploded perspective explanatory diagram of the head module, Fig. 14 is an exploded perspective explanatory diagram of the base member, head, and cover member of the same, and Fig. 15 is an exploded perspective explanatory diagram of the head module as viewed from the nozzle surface side.

[0033] The head module 110 includes a plurality of liquid ejection heads 100, a base member 102, a cover member 103, a heat dissipation member 104, a manifold 105, a printed circuit board (PCB) 106, and a module case 107.

[0034] The multiple liquid ejection heads 100 each include a nozzle plate 1 having nozzles 4 formed therein, an individual flow path plate 20 having individual liquid chambers 6 communicating with the nozzles 4 formed therein, a vibration plate 30 including a piezoelectric element 12, an intermediate flow path plate 59 laminated on the vibration plate 30, and a common flow path member 60 laminated on the intermediate flow path plate 59.

[0035] The individual flow path plate 20 , together with the individual liquid chambers 6 , forms supply-side individual flow paths 22 that communicate with the individual liquid chambers 6 , and recovery-side individual flow paths 24 that communicate with the individual liquid chambers 6 .

[0036] The intermediate flow path plate 59 forms a supply side intermediate individual flow path 56 that communicates with the supply side individual flow path 22 through the opening 31 of the vibration plate 30, and a recovery side intermediate individual flow path 52 that communicates with the recovery side individual flow path 24 through the opening 32 of the vibration plate 30.

[0037] The common flow path member 60 forms a supply-side common flow path 61 that communicates with the supply-side intermediate individual flow path 56, and a recovery-side common flow path 72 that communicates with the recovery-side intermediate individual flow path 52. The supply-side common flow path 61 communicates with the supply port 81 via a flow path 151 of the manifold 105. The recovery-side common flow path 72 communicates with the recovery port 82 via a flow path 152 of the manifold 105.

[0038] The printed circuit board 106 and the piezoelectric element 12 of the liquid ejection head 100 are connected via a flexible wiring member 92, and a driver IC (drive circuit) 91 is mounted on the flexible wiring member 92.

[0039] In this embodiment, a plurality of liquid ejection heads 100 are attached to a base member 102 at intervals. The liquid ejection heads 100 are attached to the base member 102 by inserting the liquid ejection heads 100 into openings 121 provided in the base member 102, and then bonding and fixing the peripheral edge of the individual flow path plate 20 of the liquid ejection head 100 to a cover member 103 bonded and fixed to the base member 102. In addition, a flange portion 60a provided on the outside of the common flow path member 60 of the liquid ejection heads 100 is bonded and fixed to the base member 102.

[0040] The fixing structure between the liquid ejection head 100 and the base member 102 is not limited, and they can be fixed by adhesive, caulking, screws, or the like.

[0041] Next, an example of a liquid ejection device according to the present invention will be described with reference to Figures 16 and 17. Figure 16 is a schematic explanatory diagram of the device, and Figure 17 is a plan explanatory diagram of an example of a head unit as a liquid ejection unit of the device.

[0042] The printing device 500, which is a device for ejecting this liquid, includes an input means 501 for feeding a continuous body 510, a guide and conveying means 503 for guiding and conveying the continuous body 510, such as continuous paper or sheet material, fed from the input means 501 to a printing means 505, the printing means 505 for ejecting liquid onto the continuous body 510 to print and form an image, a drying means 507 for drying the continuous body 510, and an ejection means 509 for ejecting the continuous body 510.

[0043] The continuous body 510 is fed from the original winding roller 511 of the carrying-in means 501 , guided and conveyed by the rollers of the carrying-in means 501 , the guide and conveying means 503 , the drying means 507 and the carrying-out means 509 , and wound up by the winding roller 591 of the carrying-out means 509 .

[0044] In the printing means 505, this continuum 510 is transported on a transport guide member 559 opposite the head unit 550 and head unit 555, an image is formed by liquid ejected from the head unit 550, and post-processing is performed by processing liquid ejected from the head unit 555.

[0045] Here, in the head unit 550, for example, full line type head arrays 551A, 551B, 551C, and 551D (hereinafter referred to as "head array 551" when no distinction is made between colors) for four colors are arranged from the upstream side in the transport direction.

[0046] Each head array 551 is a liquid ejection means, and ejects liquid of black K, cyan C, magenta M, or yellow Y onto the conveyed continuum 510. Note that the types and numbers of colors are not limited to these.

[0047] The head array 551 is, for example, a liquid ejection head (also simply referred to as a "head") 100 according to the present invention arranged in a staggered pattern on a base member 552, but is not limited to this.

[0048] Next, another example of a printing device as a device for ejecting liquid according to the present invention will be described with reference to Figures 18 and 19. Figure 18 is an explanatory plan view of the main parts of the device, and Figure 19 is an explanatory side view of the main parts of the device.

[0049] This printing device 400 is a serial type device, and a carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B, and movably holds the carriage 403. The main scanning motor 405 then moves the carriage 403 back and forth in the main scanning direction via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0050] This carriage 403 is equipped with a liquid ejection unit 440 that integrates a liquid ejection head 100 according to the present invention and a head tank 441. The liquid ejection head 100 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 100 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

[0051] The liquid ejection head 100 is connected to the liquid circulation device 600 described above, and liquid of a desired color is circulated and supplied.

[0052] This printing apparatus 500 is equipped with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

[0053] The conveyor belt 412 attracts the paper 410 and conveys it at a position facing the liquid ejection head 100. The conveyor belt 412 is an endless belt that is stretched between a conveyor roller 413 and a tension roller 414. The paper can be attracted by electrostatic attraction or air suction.

[0054] The conveyor belt 412 moves in a circular motion in the sub-scanning direction when the conveyor roller 413 is rotationally driven by a sub-scanning motor 416 via a timing belt 417 and a timing pulley 418 .

[0055] Furthermore, a maintenance and recovery mechanism 420 for performing maintenance and recovery of the liquid ejection head 100 is disposed on one side of the conveyor belt 412 on one side of the carriage 403 in the main scanning direction.

[0056] The maintenance and recovery mechanism 420 is made up of, for example, a cap member 421 that caps the nozzle surface (the surface on which the nozzles are formed) of the liquid ejection head 100, a wiper member 422 that wipes the nozzle surface, and the like.

[0057] The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

[0058] In the printing device 500 configured in this manner, the paper 410 is fed onto the conveyor belt 412 and adsorbed thereon, and the paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412.

[0059] Therefore, by driving the liquid ejection head 100 in accordance with an image signal while moving the carriage 403 in the main scanning direction, liquid is ejected onto the stationary paper 410 to form an image.

[0060] Next, another example of a liquid discharge unit according to the present invention will be described with reference to Fig. 20. Fig. 20 is an explanatory plan view of the main part of the unit.

[0061] This liquid ejection unit 440a is composed of the components that make up the device for ejecting the liquid, including a housing portion consisting of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid ejection head 100.

[0062] It is also possible to configure a liquid discharge unit in which the above-described maintenance and recovery mechanism 420 is further attached to, for example, the side plate 491B of this liquid discharge unit 440a.

[0063] Next, still another example of a liquid discharge unit according to the present invention will be described with reference to Fig. 21. Fig. 21 is an explanatory front view of the unit.

[0064] This liquid ejection unit 440 b is composed of a liquid ejection head 100 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444 .

[0065] The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 for electrically connecting with the liquid ejection head 100 is provided on the upper part of the flow path part 444.

[0066] In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but preferably has a viscosity of 30 mPa·s or less at room temperature and normal pressure, or upon heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a surfactant, or the like, a biocompatible material such as DNA, amino acids, proteins, or calcium, or an edible material such as a natural colorant, and the like. These liquids can be used, for example, as inkjet inks, surface treatment liquids, liquids for forming components of electronic devices or light-emitting elements, or electronic circuit resist patterns, and material liquids for 3D modeling.

[0067] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0068] A "liquid ejection unit" is a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to ejecting liquid. For example, a "liquid ejection unit" includes a liquid ejection head combined with at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0069] Here, "integrated" includes, for example, a liquid ejection head and a functional part or mechanism that are fixed to each other by fastening, bonding, engaging, etc., or one that is held movably relative to the other. The liquid ejection head, functional part, or mechanism may also be configured to be detachable from each other.

[0070] For example, some liquid ejection units have a liquid ejection head and a head tank integrated together, while others have a liquid ejection head and a head tank integrated together by being connected to each other by a tube, etc. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

[0071] Furthermore, there is a liquid ejection unit in which the liquid ejection head and the carriage are integrated.

[0072] In some liquid ejection units, the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together. In other liquid ejection units, the liquid ejection head, the carriage, and the main scanning movement mechanism are integrated together.

[0073] Furthermore, there is a liquid ejection unit in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which a liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

[0074] In some liquid ejection units, a tube is connected to a liquid ejection head equipped with a head tank or flow path components, integrating the liquid ejection head with a supply mechanism. Liquid is supplied from a liquid storage source to the liquid ejection head via this tube.

[0075] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0076] "Liquid ejection devices" include devices that have a liquid ejection head or a liquid ejection unit and eject liquid by driving the liquid ejection head. Liquid ejection devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0077] This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0078] For example, examples of "liquid ejecting devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0079] Furthermore, the term "liquid ejection device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0080] The above-mentioned "object onto which a liquid can adhere" means an object onto which a liquid can adhere at least temporarily, an object onto which the liquid can adhere and stick, an object onto which the liquid can penetrate, etc. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which a liquid can adhere.

[0081] The material of the "substance to which a liquid can adhere" may be any material to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0082] Furthermore, the "liquid ejection device" may be a device in which a liquid ejection head and an object onto which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which a liquid ejection head moves, and a line type device in which a liquid ejection head does not move.

[0083] Other examples of "liquid ejecting devices" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that ejects a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0084] In the present application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

[0085] The present invention is not limited to the above-described embodiments. Within the scope of the present invention, the elements of the above-described embodiments can be modified, added, or converted into contents that can be easily conceived by a person skilled in the art. Furthermore, two or more of the above-described embodiments can be appropriately combined. [Explanation of symbols]

[0086] 1 nozzle plate 4 nozzles 6 individual liquid chambers 10 Common liquid chamber 12 Piezoelectric element 16 Opening 50 Holding board 51 Liquid chamber member 53 Actuator member 55 Retaining member 57 Damper 70, 70a, 70b frames 71a, 71b boss (convex shape) 90 Adhesive 100, 300, 300a, 300b Liquid ejection head 400, 500 Liquid dispensing device 440, 440a, 440b Liquid dispensing units 550 head unit (liquid ejection unit) [Prior art documents] [Patent documents]

[0087] [Patent Document 1] JP 2017-71163 A [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-131948

Claims

1. a piezoelectric element that pressurizes the liquid; a holding substrate for holding the piezoelectric element; a nozzle plate having a plurality of nozzles for ejecting liquid and bonded to the holding substrate; a frame bonded to the holding substrate via an adhesive on a surface of the holding substrate opposite to a surface to which the nozzle plate is bonded; the frame has at least one convex shape on a surface to be bonded to the holding substrate, the convex shape is disposed at a position where it does not overlap with the piezoelectric element when the convex shape is projected in a liquid ejection direction, The holding substrate has a damper and includes a substrate that supports the piezoelectric element and a substrate that holds the damper. Liquid ejection head.

2. The joining surface is rectangular, The at least one convex shape is plural and is arranged at each of the four corners of the frame.

2. The liquid ejection head according to claim 1.

3. The plurality of convex shapes are arranged at arbitrary intervals from the four corners along at least two sides toward the center.

3. The liquid ejection head according to claim 2.

4. The convex shape is a height of 20 to 100 micrometers; 4. The liquid ejection head according to claim 1, wherein the surface facing the holding substrate has a circular shape or a polygonal shape with fretted corners.

5. A liquid ejection unit comprising the liquid ejection head according to claim 1 .

6. A liquid ejection device comprising the liquid ejection head according to any one of claims 1 to 4 or the liquid ejection unit according to claim 5.

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