JP7726014B2 - LIQUID EJECTION HEAD, LIQUID EJECTION UNIT, AND DEVICE FOR EJECTION OF LIQUID - Google Patents

Description

The present invention relates to a liquid ejection head, a liquid ejection unit, and a device for ejecting liquid.

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 fact that the entrapment of foreign matter affects the ejection performance of the piezoelectric element, and there is room for improvement.

The present invention aims to provide a liquid ejection head that reduces fluctuations in liquid ejection performance.

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 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 .

The present invention provides a liquid ejection head that reduces fluctuations in liquid ejection performance.

1A and 1B are diagrams illustrating an outline of a configuration example of a liquid ejection head according to an embodiment. 1A and 1B are diagrams illustrating an example of the configuration of a liquid ejection head according to a first embodiment. 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. 10A and 10B are diagrams illustrating an example of the configuration of a liquid ejection head according to a second embodiment. 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. 10A and 10B are diagrams illustrating an example of the configuration of a liquid ejection head according to Comparative Example 1. 7A and 7B are diagrams illustrating a cross section of the liquid ejection head of FIG. 6, where FIG. 7A is a cross section taken along line VIIA-VIIA of FIG. 6, and FIG. 7B is a cross section taken along line VIIB-VIIB of FIG. 10A and 10B are diagrams illustrating an example of the configuration of a liquid ejection head according to Comparative Example 2. 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. 10 is a table illustrating the incidence of Vj reduction due to pinching of a foreign object. 10A and 10B are diagrams illustrating the effect of suppressing a decrease in Vj by a boss. 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. FIG. 2 is an exploded perspective view of the head module. FIG. 2 is an exploded perspective view of the base member, the head, and the cover member. FIG. 2 is an exploded perspective view of the head module as viewed from the nozzle surface side. 1 is a schematic explanatory diagram of an example of a liquid ejection device according to the present invention. FIG. 2 is a plan view illustrating an example of a head unit of the device. 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. FIG. FIG. 10 is a plan view illustrating a main part of another example of a liquid ejection unit according to the present invention. FIG. 10 is a front view illustrating still another example of a liquid discharge unit according to the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that in each of the drawings used to explain embodiments of the present invention, components such as parts and components having the same function or shape will be assigned the same reference numerals as far as possible to distinguish them, and once they have been described, their description will be omitted.

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.

Embodiment 1.
Fig. 2 is a diagram illustrating an example of the configuration of the liquid ejection head according to 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 the 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.

The holding substrate 50 includes, 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 has an array of piezoelectric elements 12, and a holding member 55 that has recesses formed therein to accommodate the piezoelectric elements 12. A detailed description will be omitted here.

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 a surface facing the holding substrate 50 that is, for example, a quadrangle with filleted corners. An example of the shape of the facing surface is shown enlarged on the right side of FIG.

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 facing the boss 71a and 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 facing the boss 71a and the holding substrate 50.
In this way, by creating 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.

The frame 70a is configured so that the boss 71a is not positioned on the portion of the bonding surface located above the piezoelectric element 12. This suppresses deformation of the piezoelectric element 12 when a foreign object is trapped, and also prevents deformation of the piezoelectric element 12 due to the boss 71a.

It is also preferable that the bosses 71a are positioned at at least four corners of the rectangular frame 70a. This helps prevent warping and deformation of the holding substrate 50.

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.

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 the 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.

The second embodiment differs from the first embodiment in that the opposing surfaces of the bosses 71b are circular, and a plurality of bosses 71b 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.

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 contacts the boss 71. In this way, deformation of the holding substrate 50 by the boss 71 can be prevented.

The height of the boss 71 should be set higher than the expected size of foreign matter, and should be kept to a minimum height so that low-viscosity adhesives can be used. For example, the height of the boss 71 should be set to 20 to 100 micrometers (μm).

Furthermore, it is preferable that the opposing surface of the boss 71 be circular, elliptical, or polygonal, with filleted corners. This can prevent damage to the holding substrate 50 and stress concentration.

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 as not to come into contact with each other and not to be arranged above the piezoelectric elements. The bosses arranged on the frame 70 and the holding substrate 50 may be arranged alternately (or according to a predetermined rule, such as alternately arranged two by two) at any intervals from the four corners of the frame 70 along at least two sides toward the center.

<Evaluation results>
Below, the results of evaluating the fluctuations in liquid ejection performance for the liquid ejection heads of Embodiments 1 and 2 will be described 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".

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 the liquid ejection head 300p1 as seen from above, and similarly to Figs. 2 and 4, shows the arrangement of the piezoelectric element 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 in FIG. 6, and (B) is a cross section taken along line VIIB-VIIB in FIG.
The liquid ejection head 300p1 of Comparative Example 1 is the same as that of the first embodiment except that the frame 70p1 is not provided with the boss 71.

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 the liquid ejection head 300p2 as seen from above, and similarly to Figs. 2 and 4, shows the arrangement of the piezoelectric element 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 in FIG. 8, and (B) is a cross section taken along line IXB-IXB in 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. In detail, 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.

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

In FIG. 10, N is the number of liquid ejection heads, which is set to 30.
The incidence rate [%] of Vj decrease due to foreign matter entrapment indicates the percentage of heads in which Vj decrease occurred among the 30 heads.

As shown in FIG. 10, the incidence of Vj reduction due to pinching of foreign matter was smaller in the first and second embodiments in which a boss was provided and in the second comparative example 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.

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 foreign matter trapped inside. The vertical axis of each graph represents velocity Vj [m/s], and the horizontal axis represents the number of channels (ch). Here, a liquid ejection head with 400 channels is used, and the position of each channel is indicated as 0 (zero) to 400.

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 does 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, the location where the foreign object was trapped (Comparative Example 1) and the position of the boss (Comparative Example 2) are indicated by dashed circles.

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 no decrease in speed Vj occurs.
In Comparative Example 1, since the frame had no boss, foreign matter locally applied pressure to the holding substrate, causing the piezoelectric element to deform, resulting in a decrease in the velocity Vj.
In Comparative Example 2, although there was no decrease in the speed Vj due to the pinching of foreign matter, the boss applied local pressure to the holding substrate, so the speed Vj decreased.

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

The following describes an example configuration of a head module (also referred to as a "liquid ejection unit") that uses a liquid ejection head that can utilize the above-mentioned features of the present invention. Figure 12 is a cross-sectional view along the short side of the head of an example head module that uses a liquid ejection head according to the present invention, Figure 11 is an exploded perspective view of the same head module, Figure 14 is an exploded perspective view of the base member, head, and cover member, and Figure 15 is an exploded perspective view of the same head module as seen from the nozzle surface side.

The head module 110 comprises multiple 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.

The multiple liquid ejection heads 100 each include a nozzle plate 1 on which nozzles 4 are formed, an individual flow path plate 20 which forms individual liquid chambers 6 connected to the nozzles 4, a vibration plate 30 including piezoelectric elements 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.

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.

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 via the opening 31 in the vibration plate 30, and a recovery-side intermediate individual flow path 52 that communicates with the recovery-side individual flow path 24 via the opening 32 in the vibration plate 30.

The common flow path member 60 forms a supply-side common flow path 61 that communicates with the supply-side intermediate individual flow paths 56, and a recovery-side common flow path 72 that communicates with the recovery-side intermediate individual flow paths 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.

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.

In this embodiment, multiple liquid ejection heads 100 are attached to the 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 joining and fixing the peripheral edge of the individual flow path plate 20 of the liquid ejection head 100 to a cover member 103 that is joined 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 head 100 is joined and fixed to the base member 102.

The fixing structure between the liquid ejection head 100 and the base member 102 is not limited, and can be achieved by adhesive bonding, caulking, screw fixing, etc.

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 diagram of the device, and Figure 17 is a plan view of an example of a head unit serving as a liquid ejection unit of the device.

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

The continuous web 510 is fed from the original winding roller 511 of the feed-in means 501, guided and transported by the rollers of the feed-in means 501, the guide and transport means 503, the drying means 507, and the transport-out means 509, and then wound up by the winding roller 591 of the transport-out means 509.

This continuous sheet 510 is transported on a transport guide member 559 in the printing means 505, facing the head unit 550 and head unit 555, an image is formed using liquid ejected from the head unit 550, and post-processing is performed using processing liquid ejected from the head unit 555.

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

Each head array 551 is a liquid ejection means, and ejects black (K), cyan (C), magenta (M), and yellow (Y) liquid onto the transported continuum 510. Note that the types and number of colors are not limited to these.

The head array 551 is, for example, a staggered arrangement of liquid ejection heads (also simply referred to as "heads") 100 according to the present invention on a base member 552, but is not limited to this.

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

This printing device 400 is a serial type device, and the carriage 403 moves 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 holds the carriage 403 movably. The carriage 403 is then moved back and forth in the main scanning direction by the main scanning motor 405 via the timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

This carriage 403 is equipped with a liquid ejection unit 440 that integrates the 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 has a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and is mounted with the ejection direction facing downward.

The liquid ejection head 100 is connected to the liquid circulation device 600 described above, which circulates and supplies liquid of the required color.

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

The conveyor belt 412 attracts the paper 410 and transports 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, etc.

The conveyor belt 412 moves in a circular motion in the sub-scanning direction as the sub-scanning motor 416 rotates the conveyor roller 413 via the timing belt 417 and timing pulley 418.

Furthermore, a maintenance and recovery mechanism 420 that maintains and recovers the liquid ejection head 100 is arranged on one side of the carriage 403 in the main scanning direction, beside the conveyor belt 412.

The maintenance and recovery mechanism 420 is composed 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, and a wiper member 422 that wipes the nozzle surface.

The main scanning movement mechanism 493, maintenance recovery mechanism 420, and transport mechanism 495 are attached to a housing that includes side plates 491A, 491B, and a back plate 491C.

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

The carriage 403 is moved in the main scanning direction while the liquid ejection head 100 is driven in accordance with an image signal, thereby ejecting liquid onto the stationary paper 410 to form an image.

Next, another example of a liquid ejection unit according to the present invention will be described with reference to Figure 20. Figure 20 is an explanatory plan view of the main parts of the unit.

This liquid ejection unit 440a is composed of the components that make up the device that ejects 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.

It is also possible to configure a liquid ejection unit by further attaching the aforementioned maintenance and recovery mechanism 420 to, for example, the side plate 491B of this liquid ejection unit 440a.

Next, another example of a liquid ejection unit according to the present invention will be described with reference to Figure 21. Figure 21 is an explanatory front view of the unit.

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

The flow path component 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path component 444. A connector 443 is provided on the top of the flow path component 444 to electrically connect to the liquid ejection head 100.

In this 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. However, it is preferable that the viscosity of the liquid be 30 mPa·s or less at room temperature and pressure, or upon heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, etc. containing a solvent such as water or an organic solvent; a colorant such as a dye or pigment; a functionalizing material such as a polymerizable compound, resin, or surfactant; a biocompatible material such as DNA, amino acids, proteins, or calcium; or an edible material such as a natural dye. These may be used, for example, as inkjet ink, a surface treatment liquid, a liquid for forming components of electronic elements or light-emitting elements, or a resist pattern for electronic circuits, or a material liquid for three-dimensional modeling.

The energy sources used to eject 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 opposing electrodes.

A "liquid ejection unit" is a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to liquid ejection. For example, a "liquid ejection unit" includes a liquid ejection head combined 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, "integrated" includes, for example, cases in which the liquid ejection head and functional parts or mechanisms are fixed to one another by fastening, bonding, engaging, etc., or cases in which one is held movably relative to the other. The liquid ejection head, functional parts, and mechanisms may also be configured to be detachable from one another.

For example, some liquid ejection units integrate a liquid ejection head and a head tank. Others integrate the liquid ejection head and head tank by connecting them together via a tube or the like. In these liquid ejection units, a unit containing a filter can be added between the head tank and the liquid ejection head.

Also, there are liquid ejection units in which the liquid ejection head and carriage are integrated.

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

In some liquid ejection units, a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which the liquid ejection head is attached, integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

Also available liquid ejection units include a head tank or a liquid ejection head with a flow path component attached, connected to a tube, integrating the liquid ejection head with a supply mechanism. Liquid from a liquid storage source is supplied to the liquid ejection head via this tube.

The main scanning movement mechanism includes the guide member alone. The supply mechanism also includes the tube alone and the loading unit alone.

"Liquid ejection devices" include devices that are equipped with a liquid ejection head or 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.

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.

For example, "liquid ejecting devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices that eject modeling liquid onto a powder layer formed by layering powder to form a three-dimensional object.

Furthermore, "liquid ejecting devices" are not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, they also include devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

The above phrase "something to which a liquid can adhere" refers to something to which a liquid can adhere at least temporarily, and to which the liquid adheres and sticks, or to which the liquid adheres and penetrates. 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 things to which a liquid can adhere.

The above-mentioned "materials to which liquid can adhere" include paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, and other materials to which liquid can adhere, even temporarily.

Furthermore, "liquid ejection devices" include devices in which a liquid ejection head and an object onto which liquid can be attached move relatively, but are not limited to this. Specific examples include serial-type devices in which the liquid ejection head moves, and line-type devices in which the liquid ejection head does not move.

Other examples of "liquid ejecting devices" include treatment liquid application devices that eject treatment liquid onto paper to apply it to the surface of the paper for purposes such as modifying the surface of the paper, and spray granulation devices that spray a composition liquid in which raw materials are dispersed through a nozzle to granulate the raw material into fine particles.

In this application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

The present invention is not limited to the above-described embodiments. Within the scope of the present invention, each element of the above-described embodiments can be modified, added to, or converted in ways that would be easily conceivable to a person skilled in the art. Furthermore, two or more of the above-described embodiments can be combined as appropriate.

1 nozzle plate 4 nozzle 6 individual liquid chamber 10 common liquid chamber 12 piezoelectric element 16 opening 50 holding substrate 51 liquid chamber member 53 actuator member 55 holding member 57 damper 70, 70a, 70b frame 71a, 71b boss (convex shape)
90 Adhesive 100, 300, 300a, 300b Liquid ejection head 400, 500 Liquid ejection device 440, 440a, 440b Liquid ejection unit 550 Head unit (liquid ejection unit)

JP 2017-71163 A Japanese Patent Application Laid-Open No. 2005-131948

Claims (6)

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. The joining surface is rectangular,
2. The liquid ejection head according to claim 1 , wherein the at least one convex shape is a plurality of convex shapes, and the convex shapes are arranged at four corners of the frame. 3. The liquid ejection head according to claim 2 , wherein the plurality of convex shapes are arranged at arbitrary intervals from the four corners along at least two sides toward the center. 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. A liquid ejection unit comprising the liquid ejection head according to claim 1 . 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 .