JPH1034924A - Piezoelectric actuator unit, manufacture thereof, and ink jet recording head employing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a large flexure displacement by forming a common electrode on one side of a resiliently deformable plate of piezoelectric material provided with bends at a constant pitch and forming an individual electrode selectively at the bend. SOLUTION: Curved parts 2, 2, 2 shaped like ship's bottom in the longitudinal direction are formed, at a predetermined pitch, on a resilient plate 1 of about 7μm thick made of a piezoelectric material, e.g. PZT. The resilient plate 1 is provided, on one side thereof, with a common electrode 3 and, on the other side thereof, with individual electrodes 4 independently at deforming regions, i.e., the curved parts 2. When a driving voltage is applied between two electrodes 3, 4, the resilient plate 1 is contracted only at the region sandwiched by the electrodes 3, 4. Consequently, the resilient plate 1 is displaced outward and the curved part 2 becomes shallower by ΔH. When the electrodes 3, 4 are discharged under that state, the resilient plate 1 is reset. A maximum flexure can be attained by applying a drive signal selectively to the common electrode 3 and the individual electrode 4 in a region to be flexed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator unit suitable for an ink jet recording head for discharging an ink droplet from a nozzle opening by flexing and vibrating an elastic plate constituting a pressure generating chamber, and the piezoelectric vibrating unit. The present invention relates to an ink jet recording head using a slave unit.

[0002]

2. Description of the Related Art A lower electrode is formed on the surface of an elastically deformable thin plate as described in, for example, Japanese Patent Application Laid-Open Publication No. HEI 10 (1995) -1995, as an actuator unit for minutely displacing minute regions arranged at a constant pitch. A green sheet of a piezoelectric material in the form of a strip is adhered or applied in the form of a strip, which is baked to form a piezoelectric material layer, and furthermore, an upper electrode is laminated on the surface of the piezoelectric material layer, and a flexible vibration type is proposed. I have. According to such an actuator unit, it is necessary to attach a green sheet of a strip-shaped piezoelectric material and to apply the piezoelectric material in a strip shape, so that not only the work efficiency is low, but also the piezoelectric material layer There is a problem that it is easily peeled off and the durability is low. In order to solve such a problem, for example, a thin plate of a ceramic body having electromechanical displacement characteristics is used as an elastic plate as shown in JP-A-62-101455, and the ceramic body is sandwiched in a region to be displaced. An actuator in which two electrodes are formed so as to have a vertical relationship has also been proposed.

[0003]

According to this actuator unit, it is possible to attach a green sheet of a piezoelectric material,
Not only is it unnecessary to apply, but also because the piezoelectric material has a single-sheet structure, it has the advantage that peeling and the like are relatively unlikely to occur, but the elasticity and rigidity of the vibration region and the non-vibration region are almost the same. However, when the present invention is applied to a recording head that discharges ink droplets by changing the volume of a pressure generating chamber, for example, the deflection displacement is small, problems such as the necessity of excessive driving at a high voltage arise. The present invention has been made in view of such a problem, and an object thereof is to provide a single-sheet structure capable of obtaining a large deflection displacement without requiring a sticking operation or a coating operation of a piezoelectric material. Is to provide a piezoelectric vibrator unit.

A second object of the present invention is to propose a method for manufacturing the above-described piezoelectric vibrator unit.

A third object of the present invention is to provide an ink jet recording head using the above-described piezoelectric vibrator unit.

[0006]

According to the present invention, there is provided an elastic plate made of a piezoelectric material, which is elastically deformable and has a curved portion formed at a constant pitch. A common electrode formed on one surface of the elastic plate and an individual electrode selectively formed on the curved portion are provided.

[0007]

The expansion and contraction of the diaphragm is converted into a flexural displacement following the curved portion, so that the volume change rate per unit drive voltage is increased.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 shows an embodiment of a piezoelectric vibrator unit 5 according to the present invention. In FIG. 1, reference numeral 1 denotes an elastically deformable elastic plate made of a piezoelectric material such as PZT, for example, having a thickness of about 7 μm. A common electrode 3 is formed on one surface by vapor deposition of platinum or the like, or by applying a conductive paint; On the other surface, individual electrodes 4 are also provided by vapor deposition of platinum or the like or application of a conductive paint so as to be independent of the curved portion 2 serving as a deformation region.

In this embodiment, when a drive voltage is applied to the two electrodes 3 and 4, only the region between the common electrode 3 and the individual electrode 4 of the elastic plate 1 contracts, and the elastic plate 1 is contracted as shown in FIG. As shown in (1), it is displaced outward (upward in the figure) following the shape formed by the curved portion 2. That is, the elastic plate 1
Is contracted from the encircling length L to the encircling length L ′ in a state where the peripheral edge is regulated around the individual electrode 4 to generate tension, and the curvature is changed so as to be balanced with this tension. The part 2 moves upward and the depth becomes shallower by ΔH.

When the electric charges of the electrodes 3 and 4 are discharged in this state, the elastic plate 1 returns to the original state so as to follow the shape of the curved portion 2 (FIG. 1A). Hereinafter, a drive signal is selectively applied to the common electrode 3 and the individual electrodes 4 in the region to be flexibly deformed, thereby charging and discharging the piezoelectric material forming the elastic plate 1, thereby forming a single-piece structure. Only the region of the elastic plate 1 where the individual electrodes are formed can be selectively bent and deformed.

By the way, in the piezoelectric vibrator unit configured as described above, the maximum amount of deflection is obtained when the amount of deflection of the region where the individual electrodes are formed is selected to be about 1 to 2 times the thickness of the elastic plate. be able to.

FIG. 2 shows an embodiment of a method of manufacturing the above-described piezoelectric vibrator unit, in which one surface of a green sheet 10 made of a piezoelectric material such as PZT is deformed with a conductive paint or the like. Common electrode 11 by a possible conductive material
And an individual electrode 12 is formed on the other surface (I).

The sheet 10 is set with the individual electrode 12 facing the concave portion 13a of the lower mold member 13 in which the concave portion 13a corresponding to the shape of the curved portion is formed, and the upper mold member 14 has its convex portion 14a facing the individual electrode. (II) When pressed with a constant pressure, the green sheet 1 and the electrode are formed into the shape of both mold members 13 and 14 (III).

When the green sheet 10 is taken out from both mold members, the green sheet 10 is sandwiched between the mold members 13 and 14 and fired at a temperature at which the green sheet 10 can be ceramicized under a certain pressure, for example, at about 1200 ° C.
An elastic plate 18 having a curved portion 17 substantially conforming to the shapes of the irregularities 13a and 14a of the mold members 13 and 14, a common electrode 19 on one surface, and a driving electrode 2 on the curved portion 17 on the other surface.
0 is completed (IV).

In the above-described embodiment, the common electrode 11 and the individual electrode 12 are formed at the stage of the green sheet. However, only the green sheet 10 made of the piezoelectric material is processed in the same manner as described above (FIG. 3 (II) ( III))) to form an elastic plate 18 having a curved portion 17 substantially conforming to the shapes of the irregularities 13a and 14a of the mold members 13 and 14 (IV), with the common electrode 19 on one surface and the other on the other surface. The drive electrode 20 may be formed on the curved portion 17 of the surface by vapor deposition or sputtering (FIG. 3 (V)).

FIG. 4 shows another embodiment of the method of manufacturing the piezoelectric vibrator unit, in which one surface of a green sheet 10 made of a piezoelectric material such as PZT is deformable such as a conductive paint. The common electrode 11 is formed of a conductive material, and the individual electrode 12 is formed on the other surface.
When the upper mold member 14 is pressed against the surface of the second member 2, a forming member 15 having a shape suitable for forming the curved portion 17 is arranged in accordance with the pitch of the curved portion 17 to be formed (I).

The sheet 10 is formed by forming a lower mold member 13 having a concave portion 13a corresponding to the shape of the curved portion 17 and a molded member 1
5 is pressed between the upper mold material 14 and the upper mold material 14 on which the concave portion 14b is formed (II) and pressed with a constant pressure.
The surface side of the green sheet 10 is deformed along the shape of the molding member 15, and the common electrode 11 side is
Deforms following a.

The green sheet 10 is obtained from both the mold members 13 and 14.
When the green sheet 10 is fired at a temperature at which the green sheet 10 can be ceramicized, for example, at about 1200 ° C. while being sandwiched between the mold members 13 and 14 and applying a certain pressure (III), the molded member 15 Disappearing shape 1
3 has a concave portion 13a and an elastic plate 18 having a curved portion 17 substantially conforming to the shape of the molded member 15, a common electrode 19 on one surface, and a driving electrode 20 on the curved portion 17 on the other surface. The vibrator unit 21 is completed (IV).

In the embodiment shown in FIG. 4, as in the embodiment shown in FIG.
It is apparent that the same effect can be obtained even if only the green sheet 10 on which no 2 is formed is formed into a curved portion by the molding member 15 and the mold members 13 and 14 and the common electrode 11 and the individual electrode 12 are provided after firing. .

FIG. 5 shows an embodiment of an ink jet recording head using the above-described piezoelectric vibrator unit. In the drawing, reference numeral 22 denotes a spacer, which is suitable for forming a pressure generating chamber 23. A through hole is formed at a constant pitch in a ceramic plate made of zirconia or the like having a thickness of, for example, 150 μm so as to conform to the shape of the pressure generating chamber 23. As an example, the pressure generating chamber 23 has a width of about 190 to 210 μm and a length of about 2 mm so that the arrangement pitch of the nozzle openings is 90 dpi.

In the figure, reference numeral 5 denotes the above-mentioned piezoelectric vibrator unit, and the initial bending amount of the curved portion 17 is 150 μm in width so that it can function as a lid member for sealing one surface of the spacer 22. The depth of the pressure generating chamber 23 having a length of 2 mm and a depth of 150 μm is set to 5 μm or more, preferably about 30 μm or more, and generally 1 to 2 times the thickness of the elastic plate 18. Set to about.

Reference numeral 26 denotes a cover member made of zirconia for sealing the other surface of the pressure generating chamber 23, and a first communication hole 27 connected at one end of the pressure generating chamber 23 and a communication at the other end of the pressure generating chamber 23. A second communication hole 28 is formed.

Numeral 29 denotes an ink supply port forming substrate made of zirconia having one surface fixed to the lid member 26 and having an optimal flow path resistance for ink droplet ejection so as to communicate with the first communication hole 27. An ink supply port 30 is provided, and a communication hole 31 connected to the nozzle opening 36 is formed at a position facing the second through hole 28.

Reference numeral 32 denotes a common ink chamber forming plate which has a thickness suitable for forming the common ink chamber 33, for example, 150 μm.
A through hole is formed in a plate made of m zirconia in the shape of a common ink chamber 33 and a communication hole 34 connecting the pressure generating chamber 23 and the nozzle opening 36 is formed.

Reference numeral 35 denotes a nozzle plate made of a metal plate having corrosion resistance to ink such as non-corrosive steel. A nozzle opening 36 is formed on the opposite side of the pressure generating chamber 23, and a communication hole 28 is formed. , 31, 34, each pressure generating chamber 23
Are integrally bonded to the common ink chamber forming plate 32 by an adhesive layer 37 such as a heat-sealing film. Reference numeral 38 in the figure denotes an adhesive layer that joins the ink supply port forming substrate 29 and the common ink chamber forming substrate 32.

In this embodiment, when a driving voltage is applied to the two electrodes 3 and 4 facing the pressure generating chamber 23, only the region between the electrodes 3 and 4 of the elastic plate 1 contracts, As described above, the bending portion 2 moves upward and the depth becomes shallower by ΔH (FIG. 1 (b)).

As a result, the volume of the pressure generating chamber 23 increases, and the ink in the common ink chamber 33 flows into the pressure generating chamber 2 via the ink supply port 30.

When the electric charge of the elastic plate 1 is discharged through the electrodes 3 and 4 in this state, the elastic plate 1 returns to the original state so as to follow the shape of the curved portion 2 and the volume of the pressure generating chamber 23 is reduced. to shrink. As a result, the ink in the pressure generating chamber 23 is pressurized and ejects ink droplets from the nozzle openings 36.

As described above, since the elastic plate 1 is provided with the curved portion 2 in advance, the elastic plate 1 can be easily expanded and contracted as compared with a case where the flat diaphragm is expanded and contracted and deformed. The volume can be changed, and the pressure generating chamber 23 can be changed.
The rate of increase in volume for suctioning ink to the ink and the rate of reduction in volume of the pressure generating chamber 23 for discharge of ink droplets are increased, and the efficiency of ink droplet discharge for the same drive signal is improved.

In the above embodiment, one electrode 3 is formed as a common electrode. However, as shown in FIG. 6, the electrodes 39 exposed to the pressure generating chambers 23 are independently provided for each pressure generating chamber. Alternatively, it may be formed.

FIG. 7 shows another embodiment of the piezoelectric vibrator unit of the present invention applied to an ink jet recording head. In this embodiment, the center of the concave portion of the curved portion 2 is located at the center. On the line, a vibration inducing plate 40 extending in the longitudinal direction of the pressure generating chamber 23 is provided by a material having a higher rigidity than the elastic plate 1, for example, metal or ceramic.

According to this embodiment, since the vibration inducing plate 40 having greater rigidity than the piezoelectric material forming the elastic plate 1 exists on the upper surface of the area where the curved portion 2 is formed, In addition to the fact that the elastic plate 1 and the elastic plate 1 exhibit a bimetallic effect and are easily deformed, the increased thickness can sufficiently withstand the pressure during ink pressurization, and the ink can be efficiently pressurized. Can be.

In the above embodiment, the curved portion 2 is formed so that the pressure generating chamber 23 side is convex, but as shown in FIG. 8, the curved portion 2 is formed so that the outside is convex. If the vibration-inducing plate 40 is required,
The same effect is exerted even if provided on the third side.

In the above-described embodiment, the electrode 3 in contact with the pressure generating chamber 23 is exposed, but a layer of a piezoelectric material, silicon oxide, zirconia, or the like having a thickness that does not hinder vibration, for example, about 1 μm, is formed. 3 formed on the surface of the electrode 3
Is separated from the ink, the corrosion of the electrode 3 can be prevented.

In the above embodiment, the spacer 22 and the lid member 26 are formed of zirconia.
It can be made of other ceramic materials such as alumina,
Furthermore, if the same piezoelectric material is used for the spacer 22, the lid member 26, and the elastic plate 1, they can be integrally formed.

FIG. 9 shows another embodiment of the piezoelectric vibrator unit of the present invention.
Curved portions 45 are formed at a predetermined pitch from two thin plates of piezoelectric material, and individual electrodes 46, 4
6 and 46 are buried so as to form an elastic plate integrally with the common electrode 4 on the exposed surfaces of the thin plates 43 and 44 of each piezoelectric material.
7, 48 are provided.

According to this embodiment, when a drive signal is applied so that an electric field in the same direction is generated between the individual electrode 46 and the common electrodes 47 and 48, the bending portion 45 is displaced as described above.
In this embodiment, by reducing the thickness of the thin plates 43 and 44 of the piezoelectric material, an electric field required for driving can be generated at a low voltage, and low voltage driving is possible.

FIG. 10 shows an embodiment of an ink jet recording head using the above-described piezoelectric vibrator unit.
3 so that the ink droplets can be ejected at a relatively low driving voltage.

FIG. 11 shows another embodiment of the piezoelectric vibrator unit of the present invention, in which the surface of the individual electrode 4 formed on the curved portion 2 of the piezoelectric vibrator unit shown in FIG. A piezoelectric vibrator unit 51 is provided by providing a filler 50 such as a polymer material so as to match the curvature of the curved portion 2.

FIG. 12 shows an embodiment of an ink jet recording head using the piezoelectric vibrator unit 51 shown in FIG. The piezoelectric vibrator unit 51 is fixed to the spacer 22 so as to fit in the ink jet recording head 23 and is assembled into the ink jet recording head.

FIG. 13 shows another embodiment of the piezoelectric vibrator unit of the present invention. In this embodiment, the width w1 of the filler 50 shown in FIG.
In addition to providing the filler 52 whose width w2 is slightly narrower than
A piezoelectric vibrator unit 54 is provided between the curved portions 2 on the back surface, with a second filler 53 whose end reaches the boundary of the filler 52.
It is a thing.

FIG. 14 shows an embodiment of an ink jet type recording head using the piezoelectric vibrator unit 54 shown in FIG. 13, in which the convex side of each curved portion 2 is formed in the pressure generating chamber 23 of the spacer 22. When the piezoelectric vibrator unit 54 is fixed to the spacer 22 so as to fit into the space, the second filling material 52 comes into contact with the surface of the partition partitioning the pressure generating chamber 23.

FIG. 15 shows another embodiment of the piezoelectric vibrator unit according to the present invention. In this embodiment, the 0 concave portion of each bending portion 2 is provided with an upper portion irrespective of the shape of the bending portion 2. Is provided with a filler 55 so that the piezoelectric vibrator unit 56 becomes convex.

FIG. 16 shows an embodiment of an ink jet recording head using the piezoelectric vibrator unit 56 shown in FIG. 15, in which the convex side of each curved portion 2 is formed in each pressure generating chamber of the spacer 22. A piezoelectric vibrator unit 56 is fixed to the spacer 22 so as to fit in the ink jet recording head 23 and is integrated with the ink jet recording head. FIG. 17 shows another embodiment of the piezoelectric vibrator unit of the present invention. In this embodiment, a thin plate 58 made of a piezoelectric material is loaded so that an individual electrode 57 is filled in a region corresponding to the curved portion 2. 5
9 is formed into an elastic plate, common electrodes 60 and 61 are formed on the front and rear surfaces, respectively, and a filling 62 having a convex upper portion is provided on the curved portion 2 to form a piezoelectric vibrator unit 63. is there.

FIG. 18 shows an embodiment of an ink jet type recording head using the piezoelectric vibrator unit 63 shown in FIG. The piezoelectric vibrator unit 63 is fixed to the spacer 22 so as to fit in the ink jet recording head 23 and is assembled into the ink jet recording head.

FIG. 19 shows the relationship between the initial deflection amount of the bending portion of the piezoelectric vibrator unit shown in FIGS. 9, 11 and 13 and the displacement amount when a drive signal of a constant voltage is applied. This shows an example in which curved portions are formed at a pitch of 150 μm in the arrangement direction on an elastic plate having a thickness of 10 μm. From these results, as shown in FIG.
It can be seen that when the filler 50 conforming to the shape of the curved portion 2 is provided, a large displacement occurs with a small initial deflection amount.

FIG. 20 shows an embodiment of a method of manufacturing the above-described piezoelectric vibrator unit, in which a conductive paint is applied to a region of the green sheet 10 made of a piezoelectric material such as PZT to be a concave portion of a curved portion. And the like, and the common electrode 11 is formed on the other surface, if necessary, from a deformable conductive material such as a conductive paint (I). A green sheet 70 of a heat-resistant material that can be plastically deformed when pressed, for example, a ceramic or the like, which serves as a filler, is laminated (II).

When the sheet 10 is sandwiched between the lower mold member 13 having the concave portion 13a corresponding to the shape of the curved portion and the upper mold member 14 having the convex portion 14a formed thereon, and (III) is pressed with a constant pressure. , Green sheet 10, electrodes 11, 12
And the green sheet 70 is formed into the shape of both the mold members 13 and 14.

The entire green sheet 10 is taken out from both mold members, and the green sheet 10 is fired at a temperature at which the green sheet 10 can be ceramicized, for example, at about 1200 ° C. while being applied to both mold members 13 and 14 under a certain pressure. (IV), the green sheet 10 of the piezoelectric material and the green sheet 70 as the filler are each made of ceramic, and the elastic plate is completed.

In this embodiment, the common electrode 11
It is apparent that the same action is obtained even if the common electrode is formed by vapor deposition or sputtering after firing.

In the above-described embodiment, the filling portion is provided by baking. However, the filling portion may be formed by applying a polymer material or the like to the curved portion 2 of the piezoelectric vibrator unit 5 shown in FIG. Can be.

By the way, the piezoelectric vibrator unit 5 configured as described above has electrodes on the front and back surfaces, and therefore, when used in a recording head, the electrodes formed on the back surface have
In the above embodiment, since the common electrode is covered with the spacer constituting the recording head, it is difficult to connect to an external drive circuit.

FIG. 21 shows an embodiment of a spacer for solving such inconvenience. Reference numeral 72 in FIG. 21 is formed on the surface of the spacer 2 on which the piezoelectric vibrator unit is fixed. In the conductive layer, a region facing the common electrode 75 (FIG. 22) of the piezoelectric vibrator unit 74 and a region not related to the vibration of the piezoelectric vibrator unit 74, in this embodiment, two rows of pressure generating chambers 23, 23 are formed. It is formed so as to extend to the opposite central region.

The piezoelectric vibrator unit 7 is inserted into the spacer 2 provided with the conductive layer 72 formed as described above so that each curved portion 2 fits into each pressure generating chamber 23 as shown in FIG.
When the piezoelectric vibrator units 74 and 7 are set so that the width w3 is such that the gap 73 is formed in the central region when the number of the piezoelectric vibrator units 4 is set.
4 and a common electrode 75 is formed on the conductive layer 72 of the spacer.
Is formed, a part of the conductive layer 72 of the spacer is exposed as shown in FIG. Therefore, by connecting a flexible cable or the like to the exposed portion 72a, the common electrode of the piezoelectric vibrator unit 74 is connected to the external drive circuit via the conductive layer 72.

In the above embodiment, the piezoelectric vibrator unit is divided into two to expose the conductive layer. However, one piezoelectric vibrator unit is provided for two rows of pressure generating chambers. In the case of disposing, as shown in FIG. 24, the conductive layer 77 of the spacer 22 of the piezoelectric vibrator unit 76
If a notch or a window 78 is formed in a region facing the substrate, the conductive layer 72 formed on the spacer can be exposed from the notch or the window 78 even in a stacked state.

Further, in the above-described embodiment, the piezoelectric vibrator unit is preliminarily baked and then fixed integrally with the spacer 22, but it is also possible to form the flexure portion by using the spacer as a mold forming material. .

That is, as shown in FIG. 25, a common electrode 11 is formed on one surface of a green sheet 10 made of a piezoelectric material such as PZT using a deformable conductive material such as a conductive paint, and on the other surface. An individual electrode 12 is formed (I).

The sheet 10 is positioned on the spacer 22 such that the individual electrode 12 faces the pressure generating chamber 23, and the upper die 14 having the convex portions 14 a formed in accordance with the arrangement pitch of the pressure generating chamber 23. (II), the upper mold 14 is pressed with a constant pressure by using the spacer 22 as both lower molds (III), and the green sheet 1 and the electrode 1 are formed.
1 and 12 are deformed according to the shape of the convex portion 14a of the upper mold member 13.

The upper mold 14 is removed or the upper mold 14 is removed.
When the green sheet 10 is fired at a temperature at which the green sheet 10 can be ceramicized while pressed against the spacer 22, for example, about 1200 ° C., the piezoelectric vibrator unit and the spacer 22 are bonded to each other by a single positioning operation of the piezoelectric vibrator unit. It can be integrally fixed by firing without performing.

[0060]

As described above, according to the present invention, an elastic plate made of a piezoelectric material and having elastically deformable and curved portions formed at a constant pitch is formed on one surface of the elastic plate. Since the common electrode and the individual electrode selectively formed in the curved portion are provided, the expansion and contraction of the diaphragm are converted into a flexural displacement following the curved portion, so that The volume change rate can be increased.

In the present invention, since a curved portion is formed in a region of the elastic plate which seals the pressure generating chamber in a region opposed to the pressure generating chamber, displacement of extension and contraction of the diaphragm is shaped into the curved portion. It can be easily converted to flexing displacement according to the shape of the print head, and printing can be performed without the need for high voltage even in a high-density array recording head where the volume of the pressure generating chamber itself must be reduced. The diaphragm can be flexed to such an extent that the required amount of ink droplets is ejected.

[Brief description of the drawings]

FIGS. 1A and 1B are cross-sectional views showing one embodiment of a piezoelectric vibrator unit according to the present invention. FIG. 1A shows a state in which a drive signal is not applied, and FIG. Shows a state in which a drive signal is applied to the common electrode and one individual electrode.

FIGS. 2 (I) to (IV) are diagrams schematically showing one embodiment of a manufacturing process of the piezoelectric vibrator unit, respectively.

FIGS. 3 (I) to 3 (V) are views schematically showing another embodiment of another method of manufacturing the above-described piezoelectric vibrator. FIGS.

FIGS. 4 (I) to (IV) are diagrams schematically showing another embodiment of the manufacturing process of the piezoelectric vibrator unit, respectively.

FIGS. 5A and 5B are cross-sectional views each showing a state in which the piezoelectric vibrator unit of the present invention is applied to an ink jet recording head.

FIGS. 6A and 6B are cross-sectional views each showing a state in which the piezoelectric vibrator unit of the present invention is applied to an ink jet recording head.

FIGS. 7A and 7B are cross-sectional views each showing a state in which the piezoelectric vibrator unit of the present invention is applied to an ink jet recording head.

FIGS. 8A and 8B are cross-sectional views showing a state in which the piezoelectric vibrator unit of the present invention is applied to an ink jet recording head.

FIG. 9 is a sectional view showing another embodiment of the piezoelectric vibrator unit of the present invention.

FIG. 10 is a cross-sectional view showing one embodiment of an ink jet recording head using the same piezoelectric vibrator unit.

FIG. 11 is a sectional view showing another embodiment of the piezoelectric vibrator unit of the present invention.

FIG. 12 is a sectional view showing an embodiment of an ink jet recording head using the same piezoelectric vibrator unit.

FIG. 13 is a sectional view showing another embodiment of the piezoelectric vibrator unit of the present invention.

FIG. 14 is a cross-sectional view showing one embodiment of an ink jet recording head using the same piezoelectric vibrator unit.

FIG. 15 is a sectional view showing another embodiment of the piezoelectric vibrator unit of the present invention.

FIG. 16 is a cross-sectional view showing one embodiment of an ink jet recording head using the same piezoelectric vibrator unit.

FIG. 17 is a sectional view showing another embodiment of the piezoelectric vibrator unit of the present invention.

FIG. 18 is a cross-sectional view showing one embodiment of an ink jet recording head using the same piezoelectric vibrator unit.

FIG. 19 is a diagram showing a relationship between a flexure amount of a bending portion of the vibrator unit and a displacement amount by a drive signal.

FIGS. 20 (I) to (IV) are diagrams schematically showing a method of manufacturing the piezoelectric vibrator unit, respectively.

FIG. 21 is a view showing one embodiment of a conductive layer formed on a spacer in a lead-out structure of a common electrode when the piezoelectric vibrator unit is used as an actuator of a recording head.

FIG. 22 is a diagram showing one embodiment of a piezoelectric vibrator unit as an electrode structure formed on the back surface of an electrode lead-out structure when the piezoelectric vibrator unit is used as an actuator of a recording head.

FIG. 23 is a diagram showing a positional relationship between a conductive layer formed on a spacer and a common electrode of the piezoelectric vibrator unit.

FIG. 24 is a view showing another embodiment of the piezoelectric vibrator unit in the lead-out structure of the common electrode when the piezoelectric vibrator unit is used as an actuator of a recording head.

25 (I) to (III) are views schematically showing another embodiment of the manufacturing process of the piezoelectric vibrator unit.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 1 Elastic plate 2 Bending part 3 Common electrode 4 Individual electrode 5 Piezoelectric vibrator unit 22 Spacer 23 Pressure generation chamber 30 Ink supply port 33 Common ink chamber 36 Nozzle opening

Claims (20)

[Claims] 1. An elastic plate made of a piezoelectric material, which is elastically deformable and has curved portions formed at a constant pitch,
A piezoelectric vibrator unit comprising: a common electrode formed on one surface of the elastic plate; and individual electrodes selectively formed on the curved portion. 2. The piezoelectric vibrator unit according to claim 1, wherein the amount of deflection of the curved portion of the elastic plate is one to two times the thickness of the elastic plate. 3. The piezoelectric vibrator unit according to claim 1, wherein an individual electrode is buried in a region of the curved portion of the elastic plate, and a common electrode is formed on a front surface and a back surface. 4. The piezoelectric vibrator unit according to claim 1, wherein a vibration inducing plate is fixed to a side of the elastic plate where the curved portion is concave. 5. The piezoelectric vibrator unit according to claim 1, wherein a filler is provided so as to fill the curved portion of the elastic plate. 6. The piezoelectric vibrator unit according to claim 5, wherein a second filler is provided so as to contact a boundary on the other surface on which the filler is provided. 7. A step of forming a common electrode on one surface of a green sheet made of a piezoelectric material and forming an individual electrode on the curved portion on the other surface, and forming a concave portion corresponding to the shape of the curved portion. A step of pressing the formed first mold member and the second mold member having the convex portion formed thereon to form a curved portion, and a step of firing the green sheet having the curved portion formed therein. A method for manufacturing a vibrator unit. 8. A step of forming an individual electrode on the curved portion on one surface of a green sheet made of a piezoelectric material, and disposing a molded member having a shape corresponding to the shape of the curved portion on the surface of the individual electrode. And pressing the first mold member and the second mold member to form a curved portion; and firing the green sheet having the curved portion formed thereon, a method for manufacturing a piezoelectric vibrator unit. 9. The method for manufacturing a piezoelectric vibrator unit according to claim 8, wherein said molded member is made of a material which disappears by firing. 10. A curved portion of a green sheet made of a piezoelectric material is formed from a first mold material having a concave portion corresponding to the shape of the curved portion and a second mold material having a convex portion. A step of firing the green sheet on which the curved portion is formed; and a step of forming a common electrode on one surface and an individual electrode on the curved portion on the other surface. Production method. 11. A step of forming a common electrode on one surface of a green sheet made of a piezoelectric material and an individual electrode on the curved portion of the other surface, and comprising a plastically deformable material serving as a filler. Arranging a small piece on the surface of the individual electrode; pressing a first mold member having a concave portion corresponding to the shape of the curved portion and a second mold member having a convex portion to form the curved portion; And a step of firing the green sheet on which the curved portion is formed. 12. The method of manufacturing a piezoelectric vibrator unit according to claim 7, wherein the sintering is performed in a state of being loaded in the first and second mold members. 13. The method for manufacturing a piezoelectric vibrator unit according to claim 7, wherein the first mold member is a spacer having a concave portion serving as a pressure generating chamber. 14. An elastic plate made of a piezoelectric material and having a driving electrode on the front surface facing the pressure generating chamber, and an elastic plate on the back surface having at least a common electrode formed in a region facing the pressure generating chamber, and one surface. A spacer that forms the pressure generation chamber by being sealed by the elastic plate, and an ink supply port that seals the other surface of the spacer and supplies ink from a common ink chamber to the pressure generation chamber. An ink supply port forming substrate connecting the pressure generating chamber and the nozzle opening,
In the laminated ink jet recording head, a nozzle opening for receiving ink supply from the pressure generating chamber and discharging ink droplets and a flow path unit having the common ink chamber are integrally joined. An ink jet recording head having a curved portion in a region where the plate faces the pressure generating chamber. 15. The ink jet recording head according to claim 14, wherein the amount of deflection of the curved portion of the elastic plate is one to two times the thickness of the elastic plate. 16. The ink jet recording head according to claim 14, wherein an individual electrode is buried in a region of the curved portion of the elastic plate, and a common electrode is formed on a front surface and a back surface. 17. The ink jet recording head according to claim 14, wherein a vibration inducing plate is fixed to a side of the elastic plate where the curved portion is concave. 18. The piezoelectric vibrator unit according to claim 14, wherein a filler is provided so as to fill the curved portion of the elastic plate. 19. The piezoelectric vibrator unit according to claim 18, wherein a second filler is provided on a side facing the surface on which the filler is provided so as to be in contact with the filler. 20. The spacer has a conductive layer on a surface to which the elastic plate is fixed, and has an open region exposing the conductive layer in a region where the elastic plate is not involved in vibration. 15. The ink jet recording head according to claim 14, wherein a signal is transmitted to a common electrode of the elastic plate via the conductive layer exposed from an open area.