JP2000000968A - Ink jet recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head, and an ink jet recorder, in which displacement efficiency of a piezoelectric layer is enhanced. SOLUTION: An ink jet recording head comprises a pressure generating chamber 12 communicating with nozzle opening, a resilient film 50 constituting a part of the pressure generating chamber 12, an insulator film 55 formed on the resilient film 50, and a piezoelectric oscillator in a region on the insulator film 55 corresponding to the pressure generating chamber 12. Since the piezoelectric oscillator comprises a piezoelectric layer 70 provided on the insulator film 55, and at least a pair of electrodes 61, 62 sandwiching at least a part of the piezoelectric layer 70 in the breadthwise direction, displacement efficiency is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber which is in communication with a nozzle opening for ejecting ink droplets, which is constituted by an elastic film. The present invention relates to an ink jet recording head and an ink jet recording apparatus that eject ink droplets by displacement of a layer.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is formed of an elastic film, and this elastic film is deformed by a piezoelectric vibrator to pressurize ink in the pressure generating chamber to open the nozzle opening. There are two types of ink-jet recording heads that eject ink droplets from a piezoelectric vibrator, which uses a longitudinal vibration mode piezoelectric vibrator, in which a piezoelectric vibrator expands and contracts in the axial direction, and a flexural vibration mode piezoelectric vibrator. Has been put to practical use.

In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric vibrator into contact with an elastic film, so that a head suitable for high-density printing can be manufactured. A complicated process of cutting the piezoelectric vibrators into a comb-tooth shape in accordance with the arrangement pitch of the nozzle openings, and a work of positioning and fixing the separated piezoelectric vibrators in the pressure generating chambers, which complicates the manufacturing process. There is.

On the other hand, in the latter, a piezoelectric vibrator can be formed on an elastic film by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of the pressure generating chamber and firing the green sheet. However, due to the use of flexural vibration, a certain area is required, and there is a problem that high-density arrangement is difficult.

On the other hand, in order to solve the latter disadvantage of the recording head, a uniform piezoelectric material layer is formed over the entire surface of the elastic film by a film forming technique as disclosed in Japanese Patent Application Laid-Open No. 5-286131. A proposal has been made in which this piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by lithography, and a piezoelectric vibrator is formed so as to be independent for each pressure generating chamber.

According to this, the work of attaching the piezoelectric vibrator to the elastic film becomes unnecessary, and the precision of the lithography method is eliminated.
In addition to the fact that the piezoelectric vibrator can be manufactured by a simple and simple method, there is an advantage that the thickness of the piezoelectric vibrator can be reduced and high-speed driving can be performed.

[0007]

In an ink jet recording head manufactured by the above-mentioned thin film technique and lithography method, a piezoelectric vibrator comprising a lower electrode, a piezoelectric layer and an upper electrode is formed on an elastic film. I have. Therefore, an electric field is applied between the upper electrode and the lower electrode, that is, an electric field is applied in the thickness direction of the piezoelectric layer, and the elastic film is deformed by the expansion of the piezoelectric layer in the plane direction due to the application of the electric field, thereby discharging ink by deforming the elastic film. ing.

However, when the strain of the piezoelectric layer in a direction different from the electric field application direction is used, there is a problem that the displacement efficiency of the piezoelectric layer is poor.

In view of such circumstances, an object of the present invention is to provide an ink jet recording head and an ink jet recording apparatus in which the displacement efficiency of a piezoelectric layer is improved.

[0010]

According to a first aspect of the present invention, there is provided a pressure generating chamber communicating with a nozzle opening, an elastic film forming a part of the pressure generating chamber, and the elastic film. In an ink jet recording head including a piezoelectric vibrator in a region corresponding to the pressure generating chamber above, the piezoelectric vibrator includes a piezoelectric layer provided on the elastic film, and a piezoelectric layer in a width direction of the piezoelectric layer. An ink jet recording head comprising at least a pair of electrodes sandwiching at least a part thereof.

In the first aspect, since the pair of electrodes are provided in the width direction of the piezoelectric layer, an electric field can be applied in the width direction of the piezoelectric layer to expand the piezoelectric layer.

According to a second aspect of the present invention, in the first aspect, the pair of electrodes are on both sides in the width direction of the piezoelectric layer, and one of the electrodes is an individual electrode for each pressure generating chamber. The other is a common electrode of all the pressure generating chambers in the ink jet recording head.

In the second aspect, by applying an electric field between a pair of electrodes formed on both sides of the piezoelectric layer in the width direction, the piezoelectric layer can be extended in the direction of applying the electric field, and the displacement efficiency can be improved. Can be improved.

According to a third aspect of the present invention, in the first aspect, a plurality of pairs of the electrodes are provided in the width direction of the piezoelectric layer, and one of the electrodes is an individual electrode for each pressure generating chamber. The other is a common electrode of all the pressure generating chambers in the ink jet recording head.

[0015] In the third aspect, by applying an electric field between the plurality of pairs of electrodes, the intensity of the electric field applied to the piezoelectric layer is improved.

According to a fourth aspect of the present invention, in any one of the first to third aspects, an extending direction of the individual electrode and an extending direction of the common electrode are different. It is in.

[0017] In the fourth aspect, the driving unit for applying the electric field is present in the region facing the pressure generating chamber.
The wiring can be easily drawn out without requiring an interlayer insulating film and a contact hole.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the uppermost layer of the elastic film is made of an insulating film made of a material having good adhesion to the piezoelectric layer. An ink jet recording head is characterized in that:

In the fifth aspect, the adhesion between the insulator film and the piezoelectric layer is improved.

According to a sixth aspect of the present invention, in the fifth aspect, the material of the insulator film is an oxide or nitride of at least one element selected from the constituent elements of the piezoelectric layer. An ink jet recording head is characterized in that:

In the sixth aspect, the adhesion between the piezoelectric layer and the insulator film is improved.

A seventh aspect of the present invention is the ink jet recording head according to the fifth or sixth aspect, wherein the piezoelectric layer is made of PZT and the insulating film is made of ZrO ₂ .

In the seventh aspect, the adhesion between the piezoelectric layer and the insulator film is improved.

An eighth aspect of the present invention is the ink jet recording head according to the fifth to seventh aspects, wherein the elastic film comprises only the insulating film.

In the eighth aspect, the insulating film also serves as the elastic film, and the manufacturing process is simplified.

A ninth aspect of the present invention is the ink jet recording head according to any one of the first to eighth aspects, wherein the width of the pair of electrodes is wider toward the insulator film. It is in.

In the ninth aspect, the surface current is less likely to flow due to the longer distance of the piezoelectric film on the surface side, and the withstand voltage is improved.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the piezoelectric layer covers the upper surfaces of the pair of electrodes in a region facing the pressure generating chamber. An ink jet recording head is characterized in that:

In the tenth aspect, since the electrodes are covered with the piezoelectric layer, the surface current hardly flows, and the withstand voltage on the surface is improved.

According to an eleventh aspect of the present invention, in the first to tenth aspects, the pressure generation chamber is formed by anisotropic etching, and each layer of the piezoelectric vibrator is formed by film formation and lithography. An ink jet recording head is characterized in that:

In the eleventh aspect, an ink jet recording head having high-density nozzle openings can be manufactured in a large amount and relatively easily.

According to a twelfth aspect of the present invention, there is provided an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to eleventh aspects.

According to the twelfth aspect, it is possible to realize an ink jet recording apparatus in which the driving efficiency of the head is improved and the ink can be discharged satisfactorily.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention. FIG. 2 is a plan view and a cross section of one of the pressure generating chambers in the longitudinal direction. It is a figure showing a structure.

As shown in the figure, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment. As the flow path forming substrate 10, usually 150 to 3
A thickness of about 00 μm is used.
Those having a thickness of about 0 to 280 μm, more preferably about 220 μm are suitable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with a 0.1 to 2 μm-thick elastic film 50 made of silicon dioxide previously formed by thermal oxidation.

On the other hand, a silicon single crystal substrate is anisotropically etched on the opening surface of the flow path forming substrate
A nozzle opening 11 and a pressure generating chamber 12 are formed.

Here, in the anisotropic etching, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, it is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane. A second (1) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the (110) plane.
11) plane, and the etching rate of the (111) plane is about 1/1 compared to the etching rate of the (110) plane.
This is performed using the property of being 80.
By such anisotropic etching, two first (11
Precision processing can be performed based on depth processing of a parallelogram formed by the 1) plane and two oblique second (111) planes, and the pressure generating chambers 12 can be arranged at high density. it can.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic film 50 almost through 0. The amount of the elastic film 50 that is attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small.

On the other hand, each nozzle opening 11 communicating with one end of each pressure generating chamber 12 is formed narrower and shallower than the pressure generating chamber 12. That is, the nozzle opening 11 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. In addition,
Half etching is performed by adjusting the etching time.

Here, the size of the pressure generating chamber 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 11 for ejecting the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink droplets per inch, the nozzle openings 11 need to be formed with a groove width of several tens of μm with high accuracy.

Further, each pressure generating chamber 12 and a common ink chamber 31 described later are connected to each pressure generating chamber 1 of the sealing plate 20 described later.
The ink is supplied from a common ink chamber 31 through the ink supply communication port 21 formed at a position corresponding to one end of the pressure generation chamber 12. Distributed to

The sealing plate 20 is provided with an ink supply communication port 21 corresponding to each of the pressure generating chambers 12 described above, and has a thickness of, for example, 0.1 to 1 mm and a linear expansion coefficient of 300 ° C. or less. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
Each of the pressure generating chambers 1 is, as shown in FIGS.
It may be one slit hole 21A crossing the vicinity of the second ink supply side end or a plurality of slit holes 21B. The sealing plate 20 is provided on one side with the flow path forming substrate 10.
, And also serves as a reinforcing plate for protecting the silicon single crystal substrate from impacts and external forces. Also, sealing plate 2
0 forms one wall surface of the common ink chamber 31 on the other surface.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31, and is formed by punching a stainless steel plate having an appropriate thickness according to the number of nozzles and the ink droplet ejection frequency. . In the present embodiment, the thickness of the common ink chamber forming substrate 30 is 0.2 mm.

The ink chamber side plate 40 is made of a stainless steel substrate, and one surface of the ink chamber side plate 40 constitutes one wall surface of the common ink chamber 31. In the ink chamber side plate 40, a thin wall 41 is formed by forming a concave portion 40a by half etching on a part of the other surface, and an ink introduction port 42 for receiving ink supply from the outside is punched and formed. ing. The thin wall 41 is for absorbing pressure generated at the time of ink droplet ejection toward the side opposite to the nozzle opening 11, and is unnecessary for the other pressure generating chambers 12 via the common ink chamber 31. Prevents positive or negative pressure from being applied.
In the present embodiment, the ink chamber side plate 40 is made 0.2 mm in consideration of rigidity required at the time of connection between the ink introduction port 42 and an external ink supply means, and a part of the thickness is 0.02 mm.
The thickness of the ink chamber side plate 40 may be 0.02 mm from the beginning in order to omit the formation of the thin wall 41 by half etching.

On the other hand, the thickness of the elastic film 50 on the opposite side of the opening surface of the flow path forming substrate 10 is, for example, 0.2 to 3.0.
An insulator film 55 having a thickness of about 1 μm is formed on the insulator film 55.
Are formed on one side in the width direction of the piezoelectric film 70, a first electrode film 61 having a width of, for example, about 0.5 μm,
A second electrode film 62 having a width of, for example, about 0.5 μm is formed by lamination so as to sandwich the piezoelectric film 70 in a process described later, and forms a piezoelectric vibrator (piezoelectric element) 300. Here, the piezoelectric vibrator 300 refers to a portion including the piezoelectric film 70, the first electrode film 61, and the second electrode film 62.

In the present embodiment, the first electrode film 61 is used as an individual electrode of each piezoelectric vibrator 300, and the second electrode film 62 is used as a common electrode of all the piezoelectric vibrators 300. There is no problem if this is reversed. In any case, a piezoelectric vibrator is formed for each pressure generating chamber.

Here, a process for forming the piezoelectric film 70 and the like on the flow path forming substrate 10 made of a silicon single crystal substrate will be described with reference to FIG.

As shown in FIG. 4A, first, a silicon single crystal substrate wafer serving as the flow path forming substrate 10 is
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG.
On insulator 0, an insulator film 55 is formed. This insulator film 55
Is preferably formed of a material having good adhesion to the piezoelectric film 70, for example, an oxide or nitride of at least one element selected from the constituent elements of the piezoelectric film 70.
In the present embodiment, after the zirconium layer is formed on the elastic film 50, the insulating film 55 is made of zirconium dioxide by thermal oxidation in a diffusion furnace at about 1150 ° C., for example.

Next, as shown in FIG. 4C, an electrode film 60 to be the first electrode film 61 and the second electrode film 62 is formed by sputtering. As a material of the electrode film 60, that is, a material of the first and second electrode films 61 and 62, Pt or the like is preferable. This is because the piezoelectric film 70 described later, which is formed by a sputtering method or a sol-gel method, needs to be crystallized by firing at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. That is, the material of the first and second electrode films 61 and 62 must be able to maintain conductivity under such high temperature and oxidizing atmosphere. In particular, when PZT is used as the piezoelectric film 70, It is desirable that the change in conductivity due to the diffusion of PbO is small, and Pt is preferable for these reasons.

Next, as shown in FIG. 4D, the first and second electrode films 61 and 62 are located in regions where one end thereof is opposed to both sides in the width direction of the pressure generating chamber 12. Patterning as follows. At this time, it is preferable that the width of the first and second electrode films 61 and 62 is formed such that the width on the insulator film 55 side is increased.

Next, as shown in FIG. 4E, a piezoelectric film is formed on the insulator film 55 between the first electrode film 61 and the second electrode film 62 in a region corresponding to each pressure generating chamber. 70 is formed. In this embodiment, a so-called sol-gel method is used, in which a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried and gelled, and further fired at a high temperature to obtain a piezoelectric film 70 made of a metal oxide. Formed. As a material of the piezoelectric film 70, lead zirconate titanate (PZT) is used.
It is suitable when the system material is used for an ink jet recording head. The method for forming the piezoelectric film 70 is not particularly limited, and may be, for example, a sputtering method.

Further, a method of forming a PZT precursor film by a sol-gel method or a sputtering method and then growing the crystal at a low temperature by a high-pressure treatment in an aqueous alkali solution may be used. In the present embodiment, the first and second electrode films 61 and 62 are formed of Pt. However, the present invention is not limited to this. When the piezoelectric film 70 is formed at such a low temperature, As the material of the first and second electrode films 61 and 62, many metals having high conductivity, such as Al, Au, and Ni, or a conductive oxide may be used.

Thereafter, as shown in FIG. 4F, the piezoelectric film 70 is etched to pattern the piezoelectric vibrator 300. In the present embodiment, the piezoelectric film 70 is formed between the first electrode film 61 and the second electrode film 62 at the same height as these electrodes.

FIG. 5 is a plan view and a cross-sectional view showing a main part of the ink jet recording head of the present embodiment thus formed.

In the ink jet recording head of this embodiment, as shown in FIG. 5, a piezoelectric film 70 is patterned in a region facing the pressure generating chamber 12, and a first electrode film 61 and a first electrode film 61 are formed on both sides in the width direction. The second electrode film 62 is formed, and the piezoelectric vibrator 300 including the piezoelectric film 70, the first electrode film 61, and the second electrode film 62 is formed.

The first electrode film provided on one side of the piezoelectric film 70 covers one side surface of the piezoelectric layer 70 and extends from one end in the longitudinal direction onto the peripheral wall of the pressure generating chamber 12. Each of the piezoelectric vibrators 300 is an individual electrode, which is connected to an external wiring (not shown).

On the other hand, the second electrode film 62 provided on the side opposite to the first electrode film 61 of the piezoelectric film 70 is formed on one side of the piezoelectric film 70 similarly to the first electrode film 61. In the present embodiment, one end of the covering, in the present embodiment, extends from the end opposite to the extending direction of the first electrode film 61 on the peripheral wall, and the other piezoelectric vibrator 30 extends.
The second electrode film 62 extending from 0 is connected on the peripheral wall to serve as a common electrode for each piezoelectric vibrator 300, and is connected to external wiring near the end (not shown).

As described above, in the present embodiment, the first electrode film 61 serving as an individual electrode and the second electrode film 6 serving as a common electrode are used.
2 are provided on both sides in the width direction of the piezoelectric film 70.
Therefore, the first electrode film 61 and the second electrode film 6
By applying an electric field between the two, an electric field is applied to the piezoelectric film 70 in the width direction. Further, with the application of the electric field, the piezoelectric film 70 expands in the in-plane direction. That is, the direction in which the electric field is applied to the piezoelectric film 70 is the same as the direction in which the piezoelectric film 70 extends.

Here, when PZT is used for the piezoelectric film,
When the electric field application direction and the extension direction are the same, the distortion force is about 450 pC / N, whereas when the electric field application direction and the extension direction are different, it is about 150 pC / N, and the difference of about three times is obtained. is there.

Therefore, as in the present invention, the displacement efficiency of the piezoelectric film can be improved by applying an electric field in the width direction of the piezoelectric film and bending it in the same direction. In addition, since the width of the piezoelectric film can be set wider by improving the displacement efficiency, the electric field intensity applied to the piezoelectric film when driving the piezoelectric vibrator can be reduced, and the durability can be improved.

When an electric field is applied between the two electrodes as described above, if the width of the upper and lower electrodes is the same, a current easily flows on the surface of the piezoelectric film 70, so that dielectric breakdown occurs on the surface. easy. However, in the present embodiment, as described above, the widths of the first electrode film 61 and the second electrode film 62 are
Since the lower surface side, that is, the elastic film 50 side is formed wider, the withstand voltage can be improved as compared with the case where the width is the same.

Further, in the present embodiment, the first electrode film 6
Since the first and second electrode films 62 extend on the peripheral wall from the ends on the opposite sides in the longitudinal direction, a driving unit by applying an electric field exists in a region facing the pressure generating chamber 12, Displacement efficiency and durability can be improved. Further, a film for lowering the displacement efficiency of the electrodes and the like on the upper surface of the piezoelectric film 70 becomes unnecessary. Further, the wiring can be easily drawn without requiring an interlayer insulating film and a contact hole.

In the series of film formation and anisotropic etching described above, a number of chips are simultaneously formed on one wafer, and after the process is completed, a flow path forming substrate having one chip size as shown in FIG. Divide every ten. Further, the divided flow path forming substrate 10 is sequentially adhered and integrated with the sealing plate 20, the common ink chamber forming substrate 30, and the ink chamber side plate 40 to form an ink jet recording head.

The ink jet head thus constructed takes in ink from an ink inlet 42 connected to external ink supply means (not shown), fills the interior from the common ink chamber 31 to the nozzle opening 11 with ink, and
By applying an electric field between the first electrode film 61 and the second electrode film 62 formed on both sides in the width direction of the piezoelectric film 70 in accordance with a recording signal from an external drive circuit (not shown), The elastic film 50, the insulator film 55, and the piezoelectric film 70 are deformed upwardly by this deformation. After that, by releasing the electric field, the elastic film 50,
The insulating film 55 and the piezoelectric film 70 return to the original state, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 11.

In this embodiment, the piezoelectric film 70, the first electrode film 61 and the second electrode film 62 are formed to have substantially the same thickness, and the first electrode film 61 and the second electrode film 62 are formed. The upper surface of the film 62 is exposed to the outside, but is not limited to this. For example, as shown in FIG. 6, the thickness of the piezoelectric film 70 is reduced by the first electrode film 61 and the second electrode film 62. Thicker than the first
Of the p-electrode film 61 and the second electrode film 62
2a may be covered. With such a configuration,
Since the surfaces of both electrodes 61 and 62 are covered with the piezoelectric film 70, surface current does not easily flow, and the withstand voltage on the surface can be improved.

(Embodiment 2) FIG. 7 is a plan view and a sectional view showing a main part of an ink jet recording head according to Embodiment 2.

This embodiment is an example in which a plurality of pairs of electrodes are formed in the width direction of the piezoelectric layer 70A. As shown in FIG. The first electrode film 61A and the second electrode film 6 serving as a common electrode
2A is divided into a plurality of parts in a region opposed to one pressure generating chamber 12 and arranged alternately at substantially the same intervals, except that the piezoelectric film 70A is provided between these electrodes. The same is true.

In such an ink jet recording head, by applying an electric field between the first electrode film 61A and the second electrode film 62A, an electric field is applied between a plurality of pairs of electrodes. 70A bends and deforms. Thus, as described above, the elastic film 50, the insulator film 55, and the piezoelectric film 70 are deformed to be convex upward, and the ink is ejected by releasing the electric field.

In such a configuration, the electric film 70A
Since the direction in which the electric field is applied to and the direction of the bending are the same, the displacement efficiency can be improved as in the first embodiment. Further, in the present embodiment, since a plurality of pairs of electrodes are provided, the electric field intensity applied to the piezoelectric film 70 between the electrodes is improved, so that the displacement efficiency can be further improved.

(Other Embodiments) The embodiments of the present invention have been described above, but the basic configuration of the ink jet recording head is not limited to the above.

For example, in the above-described embodiment, the elastic film 5
Although the insulator film 55 is provided on the substrate 0, the invention is not limited thereto. For example, the insulator film 55 may be formed on the flow path forming substrate 10 without providing the elastic film 50 from the beginning. Is also good.

For example, in addition to the sealing plate 20 described above,
The common ink chamber forming plate 30 may be made of glass ceramic, and further, the thin film 41 may be made of glass ceramic as a separate member, and the material, structure and the like can be freely changed.

In the above-described embodiment, the nozzle openings are formed on the end surface of the flow path forming substrate 10. However, the nozzle openings protruding in a direction perpendicular to the surface may be formed.

FIG. 8 is an exploded perspective view of the embodiment configured as described above, and FIG. 9 is a sectional view of the flow path. In this embodiment, the nozzle opening 11 is formed in the nozzle substrate 120 opposite to the piezoelectric vibrator, and the nozzle communication port 22 that connects the nozzle opening 11 and the pressure generating chamber 12 is formed with the sealing plate 20 and the common ink. It is arranged so as to penetrate the chamber forming plate 30, the thin plate 41A and the ink chamber side plate 40A.

In this embodiment, the thin plate 41
A is basically the same as the above-described embodiment except that the ink chamber side plate 40A and the ink chamber side plate 40A are separate members, and the opening is formed in the ink chamber side plate 40. Is omitted.

In this embodiment, similarly to the above-described embodiment, electrodes are formed on both sides in the width direction of the piezoelectric film, and an electric field is applied in the width direction of the piezoelectric film to deform the film. The displacement efficiency can be improved.

Further, needless to say, the present invention can be similarly applied to an ink jet recording head of a type in which a common ink chamber is formed in a flow path forming substrate.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the gist of the present invention is not contradicted.

The ink jet recording head of each of these embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge and the like, and is mounted on an ink jet recording apparatus. FIG.
FIG. 1 is a schematic view showing an example of the ink jet recording apparatus.

As shown in FIG. 10, recording head units 1A and 1B having an ink jet recording head are
Cartridges 2A and 2B constituting ink supply means are detachably provided. A carriage 3 on which the recording head units 1A and 1B are mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. I have. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. Moved. On the other hand, the apparatus main body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is wound around the platen 8. It is designed to be transported.

[0085]

As described above, according to the present invention,
Since at least one pair of electrodes is provided in the width direction of the piezoelectric film, by applying an electric field between the electrodes, the piezoelectric film is distorted in the same direction as the electric field application direction and the diaphragm is flexed and deformed. Efficiency can be improved. Also,
Since the width of the piezoelectric film can be set wider by improving the displacement efficiency, the electric field intensity applied to the piezoelectric film at the time of driving can be reduced and the durability can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to an embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view of the inkjet recording head according to the first embodiment of the present invention, showing the same.

FIG. 3 is a view showing a modification of the sealing plate of FIG. 1;

FIG. 4 is a diagram showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a plan view and a cross-sectional view of a main part of the inkjet recording head according to the first embodiment of the invention.

FIG. 6 is a plan view showing a modified example of the ink jet recording head according to the first embodiment of the present invention.

FIG. 7 is a plan view and a cross-sectional view of a main part of an ink jet recording head according to Embodiment 2 of the present invention.

FIG. 8 is an exploded perspective view showing an ink jet recording head according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating an ink jet recording head according to another embodiment of the present invention.

FIG. 10 is a schematic diagram of an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 12 pressure generating chamber 50 elastic film 55 insulating film 61, 61A first electrode film 62, 62A second electrode film 70 piezoelectric film 300 piezoelectric vibrator

Claims (12)

[Claims] 1. An ink jet apparatus comprising: a pressure generating chamber communicating with a nozzle opening; an elastic film forming a part of the pressure generating chamber; and a piezoelectric vibrator in a region on the elastic film corresponding to the pressure generating chamber. In the recording head, the piezoelectric vibrator includes a piezoelectric layer provided on the elastic film, and at least a pair of electrodes sandwiching at least a part of the piezoelectric layer in a width direction. Ink jet recording head. 2. The method according to claim 1, wherein the pair of electrodes are:
An ink jet recording head, which is on both sides in the width direction of the piezoelectric layer, one of which is an individual electrode for each pressure generating chamber, and the other is a common electrode for all pressure generating chambers. 3. The pressure generating chamber according to claim 1, wherein a plurality of pairs of the electrodes are provided in the width direction of the piezoelectric layer, and one of the electrodes is an individual electrode for each pressure generating chamber and the other is a common electrode for all pressure generating chambers. An ink jet recording head comprising an electrode. 4. The ink jet recording head according to claim 1, wherein the direction in which the individual electrodes extend and the direction in which the common electrode extends are different. 5. The ink jet recording head according to claim 1, wherein the uppermost layer of the elastic film is made of an insulating film made of a material having good adhesion to the piezoelectric layer. . 6. The ink jet recording head according to claim 5, wherein the material of the insulating film is an oxide or a nitride of at least one element selected from the constituent elements of the piezoelectric layer. . 7. An ink jet recording head according to claim 5, wherein said piezoelectric layer is made of PZT, and said insulating film is made of ZrO ₂ . 8. The method according to claim 5, wherein the elastic film comprises:
An ink jet recording head comprising only the insulator film. 9. The ink jet recording head according to claim 1, wherein the width of the pair of electrodes is increased toward the insulator film. 10. The ink jet recording according to claim 1, wherein the piezoelectric layer covers the upper surfaces of the pair of electrodes in a region facing the pressure generating chamber. head. 11. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed by anisotropic etching, and each layer of the piezoelectric vibrator is formed by film formation and lithography. Inkjet recording head. 12. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.