JPH0781055A - Ink jet head - Google Patents

Abstract

PURPOSE:To obtain a small-sized high density ink jet head equipped with a multi-nozzle enhanced in response. CONSTITUTION:A plurality of partition walls 10 each composed of a piezoelectric element formed by laminating a plurality of piezoelectric plates polarized in the thickness direction thereof through conductive materials 2a, 2b are arranged on a substrate 11 and a plurality of cavities are formed in the partition walls 10 and a pressure chamber 15 is constituted by the lid 14 covering the cavities. The volume of the pressure chamber 15 is changed by the change of the piezoelectric elements in the thickness direction thereof to emit an ink liquid droplet 17 from an ink jet orifice 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an ink jet head for selectively depositing ink droplets on an image recording medium.

[0002]

2. Description of the Related Art As a conventional piezoelectric ink jet printer head, there is a Kaiser system in which the partition wall of a channel filled with ink is deformed by utilizing the bending of a piezoelectric element by a bimorph and the ink is ejected by the pressure at that time. For example, it is disclosed in Japanese Patent Publication No. 57-20904.

Further, a laminated actuator in which one end of a piezoelectric element composed of laminated piezoelectric plates is fixed to a base, the other end is made to face a nozzle opening as a free end, and an ink reservoir is formed between the free end and the nozzle opening. There is a method, which is disclosed in, for example, Japanese Patent Laid-Open No. 4-1052.

Further, there is a pressure chamber contraction system in which one piezoelectric plate polarized in the thickness direction is hollowed out to form one pressure chamber, and the piezoelectric plates are laminated to form a multi-nozzle ink jet head. JP-A-4-22317
No. 4 publication.

[0005]

However, each of the above-mentioned conventional methods has problems. In the Kaiser system, in order to form ink droplets having a large flying force, the piezoelectric element needs to be sufficiently deformed, and the piezoelectric element having an extremely small expansion / contraction rate needs to have a sufficient size. Therefore, the pressure chambers become large, the pitch of the multi-nozzles cannot be increased, and a large voltage is required to drive the piezoelectric elements.

Further, the laminated actuator system has many problems as described in detail below.

FIG. 12 is a sectional view showing the structure of the laminated actuator system disclosed in Japanese Patent Laid-Open No. 4-1052. In this structure, a part of the wall of the ink pressure chamber 90 functions as the vibration plate 91, and as described later, the free end 92a of the piezoelectric element 92 in the shape of an elongated rod supports this, so that the ink pressure chamber of high rigidity is provided. Can not adopt the container configuration of. For this reason, it takes time for the ink pressure chamber to return to the initial state in which no voltage is applied, as compared with the head configured with a hard container, and thus there is a limit to the continuous response of ink ejection.

Further, since the extension of the plate-shaped piezoelectric element 92 in the direction perpendicular to the thickness direction is utilized, the deformation amount is not integrated even if they are laminated. Since the deformation of the piezoelectric material is small, the piezoelectric element 92 needs to have a sufficient length in order to obtain a sufficient displacement for ejecting ink. For this reason, the entire head becomes large, and it is difficult and expensive to manufacture due to the complexity of its structure and the requirement for high-accuracy tolerance in joining the free end 92a of the piezoelectric element 92 and the diaphragm 91.

FIG. 13 is a sectional view showing a laminated actuator system having a structure different from that of FIG. 9 disclosed in Japanese Patent Laid-Open No. 4-1052. Free end 1 of stacked piezoelectric element 101
01a is opposed to the nozzle opening 102, and the free end 10
The ink between 1a and the nozzle opening 102 is pushed by the free end 101a of the piezoelectric element 101, and the dynamic pressure at this time ejects the ink. In this configuration, the free end 101a moves, and at the same time, the ink escapes to the ink reservoir in the direction perpendicular to the nozzle opening 102. For this reason, high efficiency cannot be expected, and the flight capability is such that the nozzle opening 102 and the free end 10 of the piezoelectric element 101 are
Since it depends on the size of the gap 1a, the accuracy requirement is strict.

Further, the volume pushed out for ejecting ink is proportional to the area and length of the piezoelectric element 101 and the applied voltage. For this reason, a sufficient size of the element is required, which causes a problem that the inkjet head becomes large.

Further, in the water-based ink, it is necessary to maintain the insulation between the filled ink and the electrode so that the electrolysis of the ink does not occur. However, since the electrode 103 is basically formed on the surface of a non-smooth piezoelectric material having pores and the like, the electrode 103 is missing on the pores, and even if an insulating film is arranged on the surface of the electrode 103, this missing part is formed. A stable film cannot be formed and complete electrical insulation cannot be obtained. Therefore, there is a problem that the ink comes into contact with the missing portion, the electrode 103 is corroded due to a chemical change of the ink, or gas is generated and the ink cannot be ejected.

An object of the present invention is to solve the problems caused by the structure and mechanism of such a conventional piezoelectric ink jet, to provide excellent performance such as ejection force and continuous response, and to drive at a low voltage. The present invention provides an inkjet head that is simple and easy to manufacture.

[0013]

In order to achieve the above object, the ink jet head of the present invention adopts the constitution described below.

A first ink jet head according to the present invention has a plurality of partition walls, each partition wall comprising a piezoelectric element in which a plurality of plate-shaped piezoelectric materials each having a cutout portion and polarized in the thickness direction are stacked with a conductive material interposed therebetween. A substrate having an array, a plurality of recesses formed by the partition walls and the substrate, and a pressure chamber configured by a lid covering the recesses, an ink supply port and an ink ejection port provided on either the substrate or the lid, respectively, a plate It is characterized in that the volume of the pressure chamber is changed by changing the thickness direction of the piezoelectric material and the ink droplets are ejected from the ink ejection port.

A second ink jet head according to the present invention has a plurality of partition walls and a partition wall composed of a piezoelectric element in which a plurality of plate-shaped piezoelectric materials each having a hollow portion and polarized in the thickness direction are laminated with a conductive material interposed therebetween. A substrate to be arranged, a plurality of depressions formed by the partition wall and the substrate, and a pressure chamber formed by an independent lid that covers each depression, and an ink supply port and an ink ejection port provided on either the substrate or the lid. ,
An ink jet head characterized in that the volume of a pressure chamber is changed by changing the thickness of a plate-shaped piezoelectric material to eject ink droplets from an ink ejection port.

In the third ink jet head according to the present invention, the partition wall of the pressure chamber is coated with a coating film so that the conductive material as an electrode for driving the plate-shaped piezoelectric material does not come into contact with the ink filled in the pressure chamber. It is characterized in that it is provided.

A fourth ink jet head according to the present invention has a plurality of partition walls and a partition wall composed of a piezoelectric element in which a plurality of plate-shaped piezoelectric materials each having a hollow portion and polarized in the thickness direction are laminated with a conductive material interposed therebetween. A substrate arranged in a matrix, a plurality of recesses formed by the partition walls and the substrate, a pressure chamber formed by a lid covering the recesses, an ink supply port and an ink ejection port respectively provided on the substrate or the lid. It is characterized in that the volume of the pressure chamber is changed by a change in the thickness direction of the plate-shaped piezoelectric material, and ink droplets are ejected from the ink ejection port.

In the fifth ink jet head according to the present invention, the position of the adjacent ink ejection port is slightly deviated from the axis orthogonal to the center line of the ink ejection port array of the ink ejection ports arranged in a matrix. It is characterized by being

[0019]

According to the above construction of the ink jet head of the present invention, since the piezoelectric element forms a part of the pressure chamber and the plate-shaped piezoelectric material is laminated, the deformation amount of the piezoelectric element should be sufficiently large. You can Therefore, a small pressure chamber can be formed, and a high-density and small inkjet head can be provided.

Further, since the pressure chamber is formed by the partition wall having a high rigidity, the substrate and the lid, there is a force enough to push back the generated internal pressure. Therefore, it is possible to provide an inkjet head having a high response frequency of the pressure chamber and a high continuous response speed.

Further, the partition also serves as a drive actuator. Therefore, it is possible to provide an inexpensive inkjet head having a small number of parts.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an ink jet head in an embodiment of the present invention will be described below with reference to the drawings.

[0023]

Embodiment 1 FIGS. 1 and 2 show an ink jet head according to a first embodiment of the present invention, FIG. 1 is a sectional view showing a pressure chamber, and FIG. FIG. Hereinafter, description will be given with reference to FIG. 1 and FIG. 2 alternately.

As shown in FIGS. 1 and 2, the first plate-shaped piezoelectric material 1a, which is polarized in the thickness direction and has a hollowed-out center, is connected to the first plate-shaped piezoelectric material 1a via the first conductive material 2a. Material 1a
And a second plate-shaped piezoelectric material 1b polarized in the opposite direction, and a third plate-shaped piezoelectric material polarized in the opposite direction to the second plate-shaped piezoelectric material 1b via the second conductive material 2b. Laminated with 1c. Similarly, the partition wall 10 is formed by sequentially laminating the required number of conductive materials and the plate-shaped piezoelectric material.

Further, the first conductive material 2a, the third conductive material 2c and the like are electrically connected to the first collector electrode 3a, and the second conductive material 2b and the fourth conductive material 2d are the second conductive material 2a and the second conductive material 2d. It is electrically connected to the collecting electrode 3b.

With this configuration, the first collector electrode 3a,
When a voltage is applied between the second collector electrodes 3b, a voltage is generated between the conductive materials and an electric field is generated in the thickness direction of the plate-shaped piezoelectric material. Therefore, the partition wall 10 functions as a piezoelectric element.

A plurality of partition walls 10 composed of this piezoelectric element are arranged on a substrate 11 formed so as to open the ink ejection ports 12, and the partition walls 10 and the substrate 11 are fixed by an adhesive material. Then, a plurality of depressions corresponding to the cut-out portions of the plate-shaped piezoelectric material are formed.

The lid 1 with the ink supply port 13 open
A plurality of independent pressure chambers 15 are formed by covering the partition walls 10 and the lid 14 with an adhesive material.

In this embodiment, the ink ejection port 12 is connected to the substrate 11
The ink supply port 13 is formed on the upper side, and the lid 14 is formed.
The ink ejection port 12 may be formed in the lid 14 and the ink supply port 13 may be formed in the substrate 11.

In addition, in the configuration of FIGS. 1 and 2, the ink ejection port 1
Although No. 2 is formed in the substrate 11, a nozzle plate which is a separate member may be attached to the substrate.

Further, the ink supplied from the ink supply port 13 is constructed so as to directly flow into the pressure chamber 15. However, as shown in FIG. An ink supply channel may be formed to prevent the ink from flowing back.

Further, the partition wall 10 is formed in a box shape with a plate-shaped piezoelectric material having an elliptical hollow portion. However, as shown in FIG. 4, a U-shaped partition wall 40 may be provided with a sealing plate 41. Good.

Further, in the description, the electrodes made of a conductive material were not formed on the bonding surface of the partition wall 10 to the substrate 11 and the bonding surface of the partition wall 10 to the lid 14. It does not matter if the piezoelectric element is driven.

Next, the operation of the ink jet head in the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

When a voltage is applied to the first drive electrode 16a and the second drive electrode 16b, which are flexible wiring boards respectively connected to the first collector electrode 3a and the second collector electrode 3b, the first conductive material is applied. A voltage is generated between 2a and the second conductive material 2b. Then, in the second plate-shaped piezoelectric material 1b, an electric field is generated in the thickness direction.

Since the second plate-shaped piezoelectric material 1b is polarized in the thickness direction in the direction opposite to the electric field, it contracts in the thickness direction. The thickness of the plate-shaped piezoelectric material is t, the deformation amount is δt, the applied voltage is V,
When the piezoelectric constant in the thickness direction is d ₃₃ , the strain is proportional to the electric field strength, and δt / t = d ₃₃ V / t, that is, δt = d ₃₃ V.

The above equation means that the amount of deformation is proportional to the voltage and does not depend on the thickness of the piezoelectric material.

The laminated plate-like piezoelectric materials undergo the same deformation as the second plate-like piezoelectric material 1b, and the deformation in the entire thickness direction is caused by the plate-like piezoelectric material having electrodes on both sides. It becomes m × δt in proportion to the number of stacked layers m, and a large amount of deformation that is m times that of one sheet can be obtained.

Since the force of this deformation is large and the lid 14 approaches the substrate 11 by almost the same amount as the amount of deformation, when the sectional area of the pressure chamber is S, the volume of S × m × δt contracts. Due to the contraction of the volume, pressure is generated in the pressure chamber 15, and the ink droplet 17 is ejected from the ink ejection port 12.

The volume change amount requires a constant amount to form the ink droplets 17, but in this embodiment, the deformation amount of one plate-shaped piezoelectric material can be amplified m times, so that the pressure chamber is disconnected. The area S can be made almost 1 / m of that of a single piezoelectric element, and a small pressure chamber can be formed.

Therefore, a plurality of pressure chambers can be mounted at high density, so that an ink jet head having a high density multi-nozzle head can be constructed.

Further, in the ink ejection characteristics, since the lid 14 is displaced toward the ink ejection port 12, this pressure directly acts on the ink ejection, and the loss due to the fluid resistance is small.

Further, since the pressure chamber 15 is constituted by the partition wall 10 which is a continuous box-shaped wall and the open portion of the pressure chamber 15 is pressed by the substrate 11 and the lid 14, the pressure chamber 15 is sufficiently resistant to the internally generated pressure. Has sufficient rigidity.

Therefore, since the response vibration to the distortion of the partition wall 10, the substrate 11 and the lid 14 caused by the ink jetting operation is performed quickly, the continuous response is good. For this reason, the number of ink jets per unit time can be increased, and high-speed printing is possible.

Further, since the amount of deformation is amplified by stacking, the applied voltage required to obtain the required amount of deformation can be made lower than in the case of one piezoelectric element. Therefore, low voltage driving is possible.

Further, the partition wall 10 is a drive actuator and also serves as a partition wall which is a structure. Therefore, the number of parts is small and there is no strict requirement for accuracy, and the manufacturing is easy and the manufacturing cost is low.

In the above description, the ink jetting operation by the contraction of the piezoelectric element has been described, but the electric field direction and the polarization direction are made the same direction, the plate-shaped piezoelectric material is extended in the thickness direction to increase the pressure volume, and thereafter. It is also possible to generate pressure and eject ink by cutting off the voltage application and returning the piezoelectric element to the original state.

Next, a manufacturing method for forming the structure of the ink jet head according to the present invention will be described. 5, FIG. 6, FIG. 7, and FIG. 8 are perspective views with a partial cross section showing a method of manufacturing an inkjet head according to a first embodiment of the present invention. The manufacturing steps will be described below with reference to these drawings.

As shown in FIG. 5, the central portion of the first green sheet 50a of piezoelectric ceramic, which is a plate-shaped piezoelectric material, is punched out in an elliptical shape so that the first exposed portion 51a remains on a part of the surface. The first conductive material 52a is formed by a printing method.

Next, as shown in FIG. 6, a new second green sheet 50b serving as a plate-shaped piezoelectric material is stacked on the first conductive material 52a, and the end surface on the opposite side of the first exposed portion 51a is stacked. The second conductive material 52b is formed by a printing method so that the second exposed portion 51b remains in the portion located at.

As described above, the green sheets and the conductive material, which are the plate-shaped piezoelectric materials, are alternately stacked and then pressure-sintered, so that the piezoelectric element block 5 as shown in FIG.
3 can be formed.

Then, as shown in FIG. 7, the ink ejection port 1
The piezoelectric element block 53 is adhered onto the glass substrate 11 on which 2 is formed. Further, after masking the upper surface 54 of the piezoelectric element block, an electrode 55 is formed by forming a conductive material such as gold (Au) on the entire surface by vapor deposition.

At this time, the first element in the piezoelectric element block 53 is
Conductive material 52a, second conductive material 52b (see FIG. 6)
Are the piezoelectric element block wall surfaces 56 and the electrodes 5
5 can be electrically connected.

Further, as shown in FIG. 8, the piezoelectric element block 53 and a part of the substrate 11 are cut by a cutting tool such as a diamond cutter. As a result, the groove 57 is formed and the piezoelectric element block 53 and the electrode 55 are divided.

Next, a glass lid 14 having the ink supply port 13 formed thereon is adhered onto the piezoelectric element,
A plurality of pressure chambers 15 can be formed.

Although the manufacturing method for forming the constitution of the ink jet head in the first embodiment of the present invention has been described above, the present invention is not limited to this manufacturing method.

For example, the substrate 11 may be made of ceramic, plastic or the like instead of glass. Also the lid 14
Is not glass but may be ceramic, plastic or metal. Further, in this embodiment, the piezoelectric ceramic is used as the plate-shaped piezoelectric material, but an organic polymer piezoelectric film can be used.

In this embodiment, no electrodes were formed on the bonding surfaces of the piezoelectric element and the substrate and between the piezoelectric element and the lid. However, a conductive material is applied to the surfaces of the piezoelectric block 53 where the substrate 11 and the lid 14 come into contact, and the electrodes are attached. By forming it, it is also possible to drive a plate-shaped piezoelectric material adjacent to the substrate and the lid.

Further, the method of taking out the electrodes is not limited to the embodiment. For example, although the vacuum deposition method was used for forming the collecting electrode, conductive coating may be applied to the end face of the piezoelectric element. The flexible wiring board may be directly connected to the collector electrode on the element.

[0060]

[Embodiment 2] FIG. 9 is an exploded perspective view, partly in section, showing the construction of an ink jet head in a second embodiment of the present invention.

As shown in FIG. 9, an ink supply port 13 is formed in each of a plurality of recesses formed by arranging a plurality of partition walls 10 having the same structure as described in the first embodiment on a substrate 11. Then, the independent lid 60 is adhered to form the pressure chamber 15.

The same first collector electrode 91a and second collector electrode 91b as those described in the first embodiment are formed on the end faces of the partition wall 10 and are electrically connected to the first drive electrode 92a and the second drive electrode 92b, respectively. Connection is made.

First drive electrode 92a and second drive electrode 9
When a voltage is applied between the lid 6 and 2b, as in the first embodiment, the lid 6
0 is displaced to the substrate 11 side. At this time, each lid 6
Since 0s are independent of each other, they do not cause mechanical interference with each other.

With the structure shown in FIG. 9, the individual pressure chambers 15 are completely independent. Therefore, the interference between the pressure chambers 15 is completely eliminated. Therefore, it is possible to provide an inkjet head having a constant ejection characteristic regardless of the print mode.

Further, the lid 60 is made of plastic, ceramic, metal or the like, and if it is lightweight and has a high elastic property, the member in which the partition wall 10 and the lid 14 are combined has a high natural frequency and is an ink jet which responds continuously at a high speed. The head is obtained.

[0066]

[Third Embodiment] FIG. 10 is a sectional view showing the arrangement of an inkjet head according to the third embodiment of the present invention.

As shown in FIG. 7, a coating film 70 formed by a chemical vapor deposition method using a polyparaxylene resin is provided on the inner surface of the partition wall 10 forming the pressure chamber 15. The coating film 70 has a high electrical insulating property and is a conductive material 71 a, 7 which is an electrode in contact with the pressure chamber 15.
1b, 71c, etc. can be electrically insulated from the pressure chamber 15 filled with ink.

Further, according to the structure of the present invention shown in FIG. 10, the conductive materials 71a, 71b, 71c, etc., which are the electrodes for driving the respective plate-shaped piezoelectric materials, form the wall surface 72 of the pressure chamber at the end surfaces. Therefore, there is no problem of defective insulating film that occurs in the pores on the surface of the plate-shaped piezoelectric material.

Further, in the structure shown in FIG. 10, the drive electrodes formed of the conductive materials 71a, 71b, 71c and the like are not in contact with the ink. Therefore, the drive electrode is not corroded or the gas is not generated due to the chemical change of the ink, and an ink jet head that can use both the water-based ink and the oil-based ink (non-aqueous) ink can be obtained.

In the third embodiment of the present invention described with reference to FIG. 10, the constitution using the coating film 70 made of polyparaxylene resin is shown. However, the present invention is not limited to this configuration. For example, the conductive materials 71a, 71b, 71c, etc. may be previously added to the pressure chamber 1.
The partition wall 10 is formed so that the piezoelectric element is pressure-sintered by printing so that it does not appear on the wall forming the pressure chamber 15.
It is also possible to have a structure in which the electrodes are not exposed on the wall surface of.

[0071]

[Embodiment 4] FIG. 11 is a perspective view, partly in section, showing the structure of an ink jet head in a fourth embodiment of the present invention.

As shown in FIG. 11, a partition 10 having the same structure as that described in the first embodiment is provided on a substrate 11 provided with an ink ejection port 12 for ejecting ink, and one of the ink ejection ports 12 is provided. Arrange and bond in a matrix so as to correspond to one.

Further, a plurality of depressions formed on the substrate 11 are covered with a lid 14 provided with an ink supply port 13 to form a plurality of pressure chambers 15 in a matrix.
As shown in FIG. 11, the partition walls 10 are arranged on the substrate 11 with the interval dimension P in the X-axis direction and the interval dimension R in the Y-axis direction.

If a voltage is applied to the partition wall 10 made of a piezoelectric material,
A pressure is generated in the pressure chamber 15 filled with ink, and an ink droplet 17 is ejected from the ink ejection port 12 arranged on the pressure chamber 15. Since the interval dimension P and the interval dimension R are small, ink can be ejected in a planar manner from the plane of the small substrate 11. Although not shown in FIG. 11, the ink is supplied from the common ink reservoir of the ink cartridge connected to the ink supply port 13.

Although the wiring pattern is not shown in FIG. 11, wiring is patterned on the back side of the substrate 11 so that each pressure chamber 15 can be driven from the outside.

The principle of operation of the structure shown in FIG. 11 is the same as that of the first embodiment, and an ink jet head having a high ejection force and good ink continuous ejection characteristics can be obtained by the effect of stacking the plate-shaped piezoelectric materials.

The manufacturing method is the same as that of the first embodiment, and the piezoelectric element having the cutouts formed in a matrix shape is attached to the substrate and then cut to form the ink jet head shown in FIG.

In the structure of the ink jet head shown in FIG. 11, the ink ejection ports 12 are arranged in a plurality of rows 80.
Since a, 80b, 80c, and 80d are formed and a large number of ink ejection ports 12 can be formed on a plane, a larger number of nozzles can be formed.

This is as described in the first embodiment of the present invention.
This is due to the characteristic configuration of the present invention that small pressure chambers can be formed and that a large number of independent pressure chambers can be formed on the surface.

Further, the positions of the ink ejection openings 12 of the adjacent ink ejection openings 80a and 80b are deviated by a dimension Q with reference to an axis orthogonal to the rows. In this way, the pitch dimension determined by the limit in which the partition walls 10 can be arranged on the substrate 11 is determined by the rows 80a and 80b of the ink ejection ports 12.
It is possible to increase the density by as many as. Since there are four rows in the figure, if the arrangement interval of the partition walls 10 is P as shown in FIG. 11, the pitch dimension of the ink ejection ports can be increased by Q = P / 4.

[0081]

As is apparent from the above description, according to the present invention, since the piezoelectric plates are laminated, the deformation amount of the piezoelectric element can be made sufficiently large. For this reason, since the ejection force is high and a smaller pressure chamber can be formed, there is an effect that a high-density and small-sized inkjet head can be obtained.

Further, a part of the pressure chamber is formed by the piezoelectric element, and the entire pressure chamber is composed of a hard wall. Therefore, there is an effect that an inkjet head having a high response frequency and a high continuous response speed can be obtained.

Furthermore, the partition also serves as a drive actuator. Therefore, since the number of parts is small and the configuration is simple, there is an effect that an inexpensive inkjet head can be obtained which is easy to manufacture.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of an inkjet head according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a partially broken structure of the inkjet head in the first embodiment of the present invention.

FIG. 3 is a sectional view showing an example of another structure of the inkjet head in the example of the present invention.

FIG. 4 is an exploded perspective view showing an example of another structure of the partition wall of the inkjet head in the example of the present invention.

FIG. 5 is a perspective view showing a manufacturing method for forming the structure of the piezoelectric element of the ink jet head in the first embodiment of the present invention.

FIG. 6 is a perspective view showing a manufacturing method for forming the structure of the piezoelectric element of the ink jet head in the first embodiment of the present invention.

FIG. 7 is a perspective view showing the manufacturing method for forming the structure of the piezoelectric element of the ink jet head in the first embodiment of the present invention.

FIG. 8 is a perspective view showing a manufacturing method for forming the structure of the piezoelectric element of the ink jet head in the first embodiment of the present invention.

FIG. 9 is an exploded perspective view showing a partially broken structure of an inkjet head according to a second embodiment of the present invention.

FIG. 10 is a cross-sectional view showing the configuration of an inkjet head according to a third embodiment of the present invention.

FIG. 11 is a perspective view showing the configuration of an inkjet head according to a fourth embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a configuration of an inkjet head in a conventional example.

FIG. 13 is a cross-sectional view showing a configuration of an inkjet head in a conventional example.

[Explanation of symbols]

 1a First plate-shaped piezoelectric material 1b Second plate-shaped piezoelectric material 1c Third plate-shaped piezoelectric material 2a First conductive material 2b Second conductive material 10 Partition wall 11 Substrate 12 Ink jet port 13 Ink supply port 14 Lid 15 pressure chamber 17 ink droplet

Claims (5)

[Claims] 1. A partition comprising a piezoelectric element having a plurality of plate-shaped piezoelectric materials laminated with a conductive material and having a hollow portion and polarized in the thickness direction, a substrate on which a plurality of partitions are arranged, and a partition. A plurality of depressions are formed by the substrate, and a pressure chamber configured by a lid that covers the depressions, and an ink supply port and an ink ejection port provided on either the substrate or the lid are provided,
An ink jet head characterized in that the volume of a pressure chamber is changed by changing the thickness of a plate-shaped piezoelectric material to eject ink droplets from an ink ejection port. 2. A partition comprising a piezoelectric element in which a plurality of plate-shaped piezoelectric materials each having a hollow portion and polarized in the thickness direction are laminated with a conductive material interposed therebetween, a substrate on which a plurality of partitions are arranged, and a partition and a substrate. A plurality of dents formed by and a pressure chamber configured by an independent lid that covers each dent, an ink supply port and an ink ejection port that are respectively provided in either the substrate or the lid, and the thickness of the plate-shaped piezoelectric material An ink jet head characterized in that the volume of a pressure chamber is changed by changing the direction to eject ink droplets from an ink ejection port. 3. A coating film is provided on the partition wall of the pressure chamber so that the conductive material as an electrode for driving the plate-shaped piezoelectric material and the ink filled in the pressure chamber do not come into contact with each other. The inkjet head according to claim 1 or claim 2. 4. A partition comprising a piezoelectric element having a plurality of plate-shaped piezoelectric materials laminated with a conductive material and having a hollow portion and polarized in the thickness direction, and a substrate having a plurality of partitions arranged in a matrix. Forming a plurality of depressions by the partition wall and the substrate,
A pressure chamber constituted by a lid covering the depression, an ink supply port and an ink ejection port respectively provided on the substrate or the lid are provided, and the volume of the pressure chamber is changed by changing the thickness direction of the plate-shaped piezoelectric material. An ink jet head characterized by ejecting ink droplets from an ink ejection port. 5. The position of an adjacent ink ejection port is slightly deviated from the axis orthogonal to the center line of the ink ejection port array of the ink ejection ports arranged in a matrix. 4. The inkjet head according to item 4.