JPH11320871A - Head and apparatus for ink-jet type recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an operation failure caused by a change of an external environment such as a humidity of a piezoelectric vibrator formed by a film formation technique, etc., by forming a sealed ambience and eliminate inconveniences due to a pressure change in the sealed ambience. SOLUTION: In an ink-Jet type recording head having a flow passage formation substrate 10 which is equipped with a piezoelectric vibrator formed at an area corresponding to a pressure generation chamber 12 communicating with a nozzle opening, a cap member 110 is united to the flow passage formation substrate 10 at the side of the piezoelectric vibrator, with securing a space of a size not to impede in movement of the piezoelectric vibrator. The cap member seals the space. A pressure change absorption means 114 for absorbing a pressure change in the space of the cap member 110 is provided, whereby inconveniences due to the internal pressure change are eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type recording head and an ink jet type recording head in which a part of a pressure generating chamber communicating with a nozzle opening is expanded and contracted by an actuator which bends and vibrates to discharge ink droplets from the nozzle opening. Related to the device.

[0002]

2. Description of the Related Art An ink jet recording head has a piezoelectric vibration type in which a pressure generating chamber is mechanically deformed to pressurize ink, and a heating element is provided in the pressure generating chamber to generate air bubbles generated by the heat of the heating element. And a bubble jet type in which the ink is pressurized by the pressure of the above. The recording heads of the piezoelectric vibration type are further classified into two types, a first recording head using a piezoelectric vibrator that is displaced in the axial direction, and a second recording head using a piezoelectric vibrator that bends and displaces. . The first recording head is capable of high-speed driving and high-density recording. On the other hand, when the piezoelectric vibrator is processed by a cutting operation, or when the piezoelectric vibrator is fixed to the pressure generating chamber, the first recording head is required to perform three operations. There is a problem that a dimensional assembly operation is required and the number of manufacturing steps is increased.

On the other hand, the second recording head uses a silicon single crystal substrate as a base material, forms channels such as pressure generating chambers and reservoirs by anisotropic etching, and forms a piezoelectric vibrator. Since the elastic film can be formed extremely thin and the pressure generating chamber and the piezoelectric vibrator can be formed with high precision by the technique of forming the film by the film forming technique such as the sputtering of the piezoelectric material, the opening area of the pressure generating chamber is made as small as possible. Thus, the recording density can be improved.

[0004]

However, since the metal plate is still used for the nozzle plate in order to maintain the processing accuracy of the nozzle opening, the above-mentioned second recording head in which the piezoelectric vibrator is formed by firing. In the same manner as described above, there is a problem that the entire recording head is distorted due to the difference in thermal expansion. Although such a problem can be solved by using a thermal expansion characteristic adjusting member as disclosed in JP-A-6-122197, when a piezoelectric vibrator is formed by sputtering a piezoelectric material, a green sheet is fired. When driving at the same voltage as compared to the one configured with
When a high electric field is applied due to the thinness of the piezoelectric vibrator and the moisture in the air is absorbed, the leakage current between the drive electrodes is likely to increase, which eventually causes a problem of dielectric breakdown.

The present invention has been made in view of such a problem, and has as its object to operate the piezoelectric vibrator formed by the film forming technique due to a change in the external environment such as humidity. An object of the present invention is to provide an ink jet type recording head and an ink jet type recording apparatus which can eliminate defects by forming a sealed atmosphere and eliminate problems caused by pressure changes in the sealed atmosphere.

[0006]

According to a first aspect of the present invention for solving the above-mentioned problems, one surface is provided with a row of pressure generating chambers which are communicated with a nozzle opening and are partitioned by a plurality of partition walls, and the other surface is provided. An ink jet recording head comprising a flow path forming substrate having an elastic film constituting a part of the pressure generating chamber, and having a piezoelectric vibrator in a region corresponding to the pressure generating chamber. Joined to the transducer side,
An ink jet recording head comprising: a cap member for sealing the space while securing a space that does not hinder the movement; and a pressure change absorbing means for absorbing a pressure change in the space of the cap member. It is in.

In the first aspect, the piezoelectric vibrator is isolated from the outside by the cap member, and the pressure inside the cap is kept constant by the pressure change absorbing means.

A second aspect of the present invention is the ink jet recording head according to the first aspect, wherein the pressure change absorbing means is an elastic porous member provided in the cap member. .

In the second aspect, the pressure fluctuation inside the cap member is absorbed by the elastic porous member provided in the cap member.

According to a third aspect of the present invention, in the first aspect, the pressure change absorbing means is a flexible portion provided on the cap member, and a space in the cap member defines the flexible portion. An ink jet type recording head characterized by being opposed to the outside through the intermediary.

In the third aspect, the pressure change in the cap member is absorbed by the flexible portion.

According to a fourth aspect of the present invention, in the first aspect, there is provided a dummy pressure generating chamber to which ink is not supplied adjacent to the pressure generating chamber, and wherein the pressure change absorbing means comprises: An ink jet recording head is a flexible plate which is a boundary between a generation chamber and a space in the cap member.

In the fourth aspect, the pressure change in the cap member is absorbed by the flexible plate serving as a boundary between the dummy pressure generating chamber and the space of the cap member.

According to a fifth aspect of the present invention, there is provided an ink jet recording head according to the fourth aspect, wherein the flexible plate comprises at least the elastic film.

In the fifth aspect, the pressure change in the cap member is absorbed by the elastic film.

A sixth aspect of the present invention is the ink jet recording head according to the first aspect, wherein the entire cap member is made of a flexible material.

In the sixth aspect, the pressure change in the cap member is absorbed by the entire cap member.

According to a seventh aspect of the present invention, there is provided an ink jet recording head according to the sixth aspect, wherein the flexible material is paper or aluminum coated with an inner surface.

In the seventh aspect, the pressure change in the cap member is effectively absorbed.

According to an eighth aspect of the present invention, in the ink jet recording head according to the sixth or seventh aspect, the flexible material is bonded to the flow path forming substrate by welding aluminum. is there.

In the eighth aspect, the cap member is easily and reliably joined to the flow path forming substrate.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the flow path forming substrate is made of a silicon single crystal substrate, and the pressure generating chamber is formed by anisotropic etching. An ink jet recording head is characterized in that each layer of the piezoelectric vibrator is formed by film formation and lithography.

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

[0024] In a tenth aspect of the present invention, in any one of the first to ninth aspects, a reservoir communicating with the pressure generating chamber is defined in the flow path forming substrate, and the nozzle having the nozzle opening is provided. An ink jet recording head is characterized in that the plates are joined.

In the tenth aspect, an ink jet recording head that discharges ink from the nozzle openings can be easily realized.

According to an eleventh aspect of the present invention, in any one of the first to ninth aspects, the flow path forming substrate includes a common ink chamber for supplying ink to the pressure generation chamber; A flow path unit for forming a flow path communicating with the nozzle opening is joined to the ink jet recording head.

In the eleventh aspect, ink is ejected from the nozzle openings via the flow path unit.

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 capable of preventing head malfunction due to a change in the external environment and performing good ink ejection.

[0030]

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, and FIG. 2 is a cross section of one of the pressure generating chambers in the longitudinal direction and the width direction. It is a figure showing a structure.

As shown in the figure, the flow path forming substrate 10 is a single crystal silicon substrate having a plane orientation of (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 an elastic film 50 having a thickness of 1 to 2 μm and made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on a silicon single crystal substrate,
Row 1 of pressure generating chambers 12 partitioned by a plurality of partition walls 11
3 are arranged in a substantially U-shape so as to surround three rows of two rows and two rows 13 of the two pressure generating chambers 12, and each pressure generating chamber 12 and the reservoir 14 are communicated with a constant fluid resistance. Ink supply ports 15 are formed. In addition,
The reservoir 1 is located at a substantially central portion of the reservoir 14 from outside.
4 is provided with an ink introduction hole 16 for supplying ink.

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. Here, the elastic film 50 is
The amount attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small. Each ink supply port 15 communicating with one end of each pressure generating chamber 12 is formed shallower than the pressure generating chamber 12. That is, the ink supply port 15
Is formed by etching (half-etching) the silicon single crystal substrate halfway in the thickness direction. Note that the half etching is performed by adjusting the etching time.

On the opening side of the flow path forming substrate 10,
A nozzle plate 18 in which a nozzle opening 17 communicating with the ink supply port 15 of each pressure generating chamber 12 on the opposite side is formed is fixed via an adhesive or a heat welding film. The thickness of the nozzle plate 18 is, for example, 0.1 to 1
mm, the coefficient of linear expansion is 300 ° C. or less, for example, 2.5 to
It is made of 4.5 [× 10 ⁻⁶ / ° C.] glass-ceramic or non-rusting steel. The nozzle plate 18 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force.

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 17 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 17 need to be formed with a diameter of several tens of μm with high precision.

On the other hand, the thickness of the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10 is, for example, about 0.5 μm.
A lower electrode film 60, a piezoelectric film 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are formed by lamination in a process to be described later. (Piezoelectric element) 300 is constituted. Here, the piezoelectric vibrator 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, the piezoelectric vibrator 30
0 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric vibrator 300, and the upper electrode film 80 is used as an individual electrode of the piezoelectric vibrator 300. Absent. In any case, the piezoelectric active portion is formed for each pressure generating chamber. In the example described above, the elastic film 50 and the lower electrode film 60 function as a diaphragm, but the lower electrode film may also serve as the elastic film.

In this embodiment, the piezoelectric active portion 320 composed of the patterned piezoelectric film 70 and the upper electrode film 80 is provided in a region facing the pressure generating chamber 12.
The piezoelectric film 70 and the upper electrode film 80 constituting the piezoelectric active portion 320 are continuously extended to a region facing the ink supply port 15 and the reservoir 14. The lead electrode 100 is connected to the upper electrode film 80 in a region facing the reservoir 14 via a contact hole 90a described later.

Here, a process of 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 FIGS.

As shown in FIG. 3A, 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. 3B, a lower electrode film 60 is formed by sputtering. Pt or the like is preferable as the material of the lower electrode film 60. This is because a piezoelectric film 70 to be described later, which is formed by sputtering or a sol-gel method, has a thickness of 600 to 100 in an air atmosphere or an oxygen atmosphere after the film formation.
This is because it is necessary to perform crystallization by firing at a temperature of about 0 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere. In particular, when PZT is used for the piezoelectric film 70, the conductivity of the material by diffusion of PbO is increased. It is desirable that there is little change in sex, and Pt is preferred for these reasons.

Next, as shown in FIG. 3C, a piezoelectric film 70 is formed. Sputtering can be used to form the piezoelectric film 70. In the present embodiment, however, a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried, gelled, and fired at a high temperature. A so-called sol-gel method for obtaining a piezoelectric film 70 made of a metal oxide is used. As a material for the piezoelectric film 70, a lead zirconate titanate (PZT) -based material is suitable when used in an ink jet recording head.

Next, as shown in FIG. 3D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as Al, Au, Ni, and Pt, and a conductive oxide. In this embodiment,
Pt is formed by sputtering.

Next, as shown in FIG. 3E, the upper electrode film 80 and the piezoelectric film 70 are patterned so that a piezoelectric vibrator is provided for each pressure generating chamber 12. FIG. 3E shows a case where the piezoelectric film 70 is patterned with the same pattern as the upper electrode film 80. However, as described above, the piezoelectric film 70 does not necessarily need to be patterned. This is because, when a voltage is applied using the pattern of the upper electrode film 80 as an individual electrode, an electric field is applied only between each upper electrode film 80 and the lower electrode film 60 which is a common electrode. This has no effect. However, in this case, it is necessary to apply a large voltage to obtain the same excluded volume. Therefore, it is preferable to pattern the piezoelectric film 70 as well. After that, the lower electrode film 60 may be patterned to remove unnecessary portions, for example, the vicinity of the inside of the edges on both sides in the width direction of the pressure generating chamber 12. The removal of the lower electrode film 60 is not necessarily performed, and when it is removed, the thickness may be reduced without removing all of the lower electrode film 60.

Here, the patterning is performed by forming a resist pattern and then performing etching or the like.

The resist pattern is formed by applying a negative resist by spin coating or the like, and performing exposure, development, and baking using a mask having a predetermined shape. In addition,
Of course, a positive resist may be used instead of the negative resist.

The etching is performed using a dry etching apparatus, for example, an ion milling apparatus. In addition,
After the etching, the resist pattern is removed using an ashing device or the like.

As a dry etching method, a reactive etching method or the like may be used other than the ion milling method. It is also possible to use wet etching instead of dry etching, but the patterning accuracy is somewhat inferior to the dry etching method, and the upper electrode film 8
Since the material of 0 is also limited, it is preferable to use dry etching.

Next, as shown in FIG. 4A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80 and the side surfaces of the piezoelectric film 70. The material of the insulator layer 90 is
In this embodiment, a negative photosensitive polyimide is used.

Next, as shown in FIG. 4B, a contact hole 90a is formed in a portion facing the reservoir 14 by patterning the insulator layer 90. This contact hole 90a is provided with a lead electrode 100 described later.
And the upper electrode film 80.

Next, for example, a lead electrode 100 is formed by depositing a conductor such as Cr-Au on the entire surface and then patterning it.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 4C, the silicon single crystal substrate is subjected to anisotropic etching with the above-described alkali solution to form the pressure generating chamber 12 and the like.

In the present embodiment, the cap member 11 has a space on the elastic film 50 on the side of the piezoelectric active portion that does not hinder the driving of the piezoelectric active portion, and seals the piezoelectric active portion.
0 is provided.

The cap member 110 is provided in a region opposed to each row 13 of the pressure generating chambers 12 on the joint side with the elastic film 50 in a concave portion 11 made of a space not in contact with the piezoelectric active portion.
It has a partition wall 111 that partitions the second partition 2.

The cap member 110 is fixed to the surface of the elastic film 50 with an adhesive or the like, and seals the piezoelectric active portion in each recess. In the present embodiment, the cap member 1
Although 10 is bonded on the elastic film 50, the present invention is not limited to this. For example, the piezoelectric film 70 may be removed and bonded to the lower electrode film 60. In any case,
The cap member 110 can be securely bonded.

Further, in the present embodiment, a through groove 113 connecting the concave portion 112 and the outside is formed substantially in the center of the concave portion 112 in the direction of the row 13 of the pressure generating chamber in the row 13 direction. The opening outside the through groove 113 is closed by a flexible portion 114 that absorbs a pressure change in the concave portion 112 by deformation. The flexible portion 114 is formed of an elastically deformable member, for example, a thin film of resin, rubber, metal, or the like, and can be easily deformed with a change in pressure in the concave portion 112 as shown in the schematic diagram of FIG. Things.

The sizes of the through groove 113 and the flexible portion 114 are not particularly limited, as long as the change in pressure in each recess 112 can be absorbed. Alternatively, a plurality of through holes and a flexible portion for closing the through holes may be provided.

With such a configuration, the piezoelectric body active portion
It is sealed by the cap member 110, thereby preventing operation failure due to the external environment. Further, even when the pressure in the concave portion 112 sealing the piezoelectric active portion changes, the pressure in the concave portion 112 can be kept constant by deforming the flexible portion 114. Therefore, it is possible to easily prevent a malfunction of the piezoelectric active portion due to a pressure change in the concave portion 112.

In the above-described series of film formation and anisotropic etching, a large number of chips are simultaneously formed on one wafer, and after the process is completed, a flow path of one chip size as shown in FIG. It is divided for each forming substrate 10. Also,
The divided flow path forming substrate 10 is sequentially bonded to the nozzle plate 18 and the cap member 110 to form an ink jet recording head. Thereafter, the ink jet recording head is fixed to the holder 105, mounted on a carriage, and incorporated in the ink jet recording apparatus.

The ink jet head thus configured takes in ink from an ink inlet 16 connected to an external ink supply means (not shown), fills the inside from the reservoir 14 to the nozzle opening 17 with ink, and then supplies the ink to the outside (not shown). By applying a voltage between the lower electrode film 60 and the upper electrode film 80 via the lead electrode 100 in accordance with the recording signal from the drive circuit of FIG. The pressure in the generation chamber 12 increases, and ink droplets are ejected from the nozzle opening 17.

(Embodiment 2) FIG. 6 is an exploded perspective view showing an ink jet recording head according to Embodiment 2.
FIG. 7 is a diagram illustrating a cross-sectional structure in a width direction of the pressure generation chamber according to the second embodiment.

In the present embodiment, as shown in the figure, the cap member 120 is provided with a partition wall 111 for partitioning a recess 112A, which is a space that does not hinder the driving of the piezoelectric vibrator.
A, and a second cap member 1 that seals one surface of the first cap member 121.
The first cap member 121 and the second cap member 122 are fixed with an adhesive or the like.
In addition, a communication portion 115 that communicates adjacent recesses 112A is provided at an end of the partition wall 111A opposite to the flow path forming substrate 10 and substantially at the center in the longitudinal direction of the pressure generation chamber 12,
All recesses 112A corresponding to the rows 13 of the pressure generating chambers 12
Is the same as in the first embodiment except that the communication is made.

Therefore, also in this embodiment, as in the first embodiment, the piezoelectric active portion can be shut off from the outside by the cap member 120, and malfunctions due to the external environment can be prevented. Also, the pressure change of each recess 112A is
Since the pressure is absorbed by the flexible portion 114 through the communication hole 115, the pressure inside the cap 120 can be kept constant. Thereby, it is possible to prevent a malfunction of the piezoelectric active portion due to a change in the internal pressure.

In the present embodiment, the communication hole 115 is provided in the partition wall 111A. However, when the through groove 113 is provided in all the pressure generating chambers 12, the through hole 11 is provided.
3, the pressure generating chambers 12 communicate with each other, so that the same effect can be obtained without providing the communication holes 115.

(Embodiment 3) FIG. 8 is a diagram showing a cross-sectional structure in the width direction of a pressure generating chamber according to Embodiment 3.

In the present embodiment, as shown in FIG. 8, the pressure generating chamber located at one end of the row 13 of the pressure generating chambers is a dummy pressure generating chamber 12A, and a region facing the pressure generating chamber 12A. Except that the lower electrode film 60 is removed and the removed portion of the elastic film 50a functions as a flexible plate for absorbing a pressure change in the recess 112A. It is.

With such a configuration, the elastic film 50a is deformed in accordance with the pressure change in the concave portion 112A, so that the pressure in the concave portion 112A is kept constant, and the operation of the piezoelectric active portion according to the pressure change is performed. Defects are prevented. In addition,
In order to enhance the effect of pressure absorption, it is preferable that the dummy pressure generation chamber 12A communicates with the outside.

Further, in this embodiment, only the elastic film 50a is provided in the portion facing the dummy pressure generating chamber 12A. However, the present invention is not limited to this. For example, the lower electrode film 60 may be left. Alternatively, a part of the elastic film 50 may be removed. The flexible plate at the boundary between the dummy pressure generating chamber 12A and the cap member 120A is not limited to the elastic film, and may be formed of another member.

(Embodiment 4) FIG. 9 is a view showing a cross-sectional structure in a longitudinal direction and a width direction of a pressure generating chamber according to Embodiment 4.

In the present embodiment, instead of providing a flexible portion for absorbing a pressure change inside the cap 120, as shown in FIG. 9, the depth d of the concave portion 112A of the cap member 120 is increased and the upper electrode film is formed. The second embodiment is the same as the second embodiment except that a porous material 116 impregnated with silicone oil or the like having a low water content is loaded on the inner side of the concave portion 112A so as not to come into contact with 80.

According to the present embodiment, as in the above-described embodiment, the piezoelectric active portion can be cut off from the outside, and operation failure due to the external environment can be prevented. Further, the deformation of the porous material 116 impregnated with silicone oil or the like absorbs a change in pressure inside the cap 120, so that a malfunction of the piezoelectric active portion due to the change in internal pressure can be prevented.

In this embodiment, the adjacent recesses 11 are used.
Since the communication hole 115 communicating the 2A is formed, the porous member 116 is impregnated with silicone oil or the like so as to absorb the internal pressure change of all the recessed portions 112A. As long as 116 has closed cells, a porous member that is not impregnated with silicone oil or the like may be provided, and this can sufficiently absorb changes in internal pressure.

(Embodiment 5) FIG. 10 is a diagram showing a cross-sectional structure in the longitudinal direction of a pressure generating chamber according to Embodiment 5.

This embodiment is an example in which the entire cap member is formed of a flexible material and directly joined to the flow path forming substrate.
As shown in FIG. 10, the basic structure is the same as that of the first embodiment except that no flexible portion is provided.

As the flexible material, for example, paper or aluminum film having an inner surface coated with a resin can be used. By using such a cap member, a pressure change in the internal space can be absorbed by deformation of the cap member.

Further, such a flexible material is relatively inexpensive, and can reduce the cost of molding and the like.
For example, there is an effect that it can be easily joined to the flow path forming substrate by aluminum welding.

In this embodiment, the cap member is bonded on the elastic film 50 in order to surely bond the cap member. However, the present invention is not limited to this, and the cap member may be bonded on the flow path forming substrate or the lower electrode film 60. It goes without saying that it is good.

(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 reservoir 14 is formed together with the pressure generating chamber 12 in the flow path forming substrate 10, but a member forming the common ink chamber may be provided so as to overlap the flow path forming substrate 10. Good.

FIG. 11 shows a partial cross section of the ink jet recording head thus constructed. In this embodiment,
A sealing plate 160, a common ink chamber forming plate 170, a thin plate 180, and an ink chamber side plate 190 are sandwiched between a nozzle substrate 18A having a nozzle opening 17A and a flow path forming substrate 10A, and penetrate these. As described above, the pressure generating chamber 12B
And a nozzle communication port 31 that communicates with the nozzle opening 17A. That is, the common ink chamber 32 is defined by the sealing plate 160, the common ink chamber forming plate 170, and the thin plate 180, and each of the pressure generating chambers 12 </ b> B and the common ink chamber 32 are formed in the sealing plate 160. The ink is communicated via the ink communication hole 33.

Further, the supply ink chamber 32 is provided in the sealing plate 160.
Also, an ink introduction hole 34 for introducing ink from outside is formed.

Further, in the ink chamber side plate 190 located between the thin plate 180 and the nozzle substrate 18A, a penetrating portion 35 is formed at a position opposed to each of the supply ink chambers 32. The thin wall 180 allows the pressure directed to the opposite side to the nozzle opening 17A to be absorbed by the thin wall 180, so that the other pressure generating chambers need not have an unnecessary positive or negative pressure via the common ink chamber 32. Negative pressure can be prevented from being applied. Note that the thin plate 180 and the ink chamber side plate 190 may be formed integrally.

In this embodiment as well, a cap member provided on the side opposite to the opening surface of the flow path forming substrate 10A for sealing the piezoelectric active portion has a pressure change in a space for sealing the piezoelectric active portion. By providing a flexible part to absorb,
It is possible to prevent a malfunction due to a change in pressure of the piezoelectric active portion.

In each of the embodiments described above, a thin-film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example.
Of course, the present invention is not limited to this. For example, a piezoelectric film is formed by laminating substrates to form a pressure generating chamber, or a piezoelectric film is formed by attaching a green sheet or by screen printing, or a piezoelectric film formed by crystal growth. The present invention can be applied to ink jet recording heads having various structures, such as those that form a recording medium.

Further, in each of the above-described embodiments, the connection portion between the upper electrode film and the lead electrode may be provided at any place, and may be at any end or the center of the pressure generating chamber. .

Further, the example in which the insulator layer is provided between the piezoelectric vibrator and the lead electrode has been described. However, the present invention is not limited to this. The conductive film may be thermally welded, and the anisotropic conductive film may be connected to the lead electrode, or may be connected using various bonding techniques such as wire bonding.

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 the 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. 12, the recording head units 1A and 1B having the ink jet recording heads
Cartridges 2A and 2B constituting ink supply means are provided detachably, and 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.

Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, 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.

[0093]

As described above, according to the present invention, a cap member having a concave portion having a space that does not hinder the driving of the piezoelectric active portion is provided, and the cap member absorbs a pressure change in the concave portion. Since the flexible portion is provided, the malfunction of the piezoelectric active portion due to the external environment can be prevented, and the malfunction due to the pressure change in the concave portion can also be prevented.

[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 diagram showing a cross-sectional structure of an ink jet recording head according to an embodiment of the present invention in a longitudinal direction of pressure generating chambers and an arrangement direction of the pressure generating chambers.

FIG. 3 is a view showing a thin film manufacturing process according to the first embodiment of the present invention.

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

FIG. 5 is a diagram schematically showing a flexible portion.

FIG. 6 is an exploded perspective view of an ink jet recording head according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a cross-sectional structure in a longitudinal direction of a pressure generating chamber of an ink jet recording head according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating a cross-sectional structure in a longitudinal direction of a pressure generating chamber of an ink jet recording head according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a cross-sectional structure of an ink jet recording head according to a fourth embodiment of the present invention in a longitudinal direction of the pressure generating chambers and an arrangement direction of the pressure generating chambers.

FIG. 10 is a diagram showing a cross-sectional structure in a longitudinal direction of a pressure generating chamber of an ink jet recording head according to a fifth embodiment of the present invention.

FIG. 11 is a diagram showing a cross-sectional structure in a longitudinal direction of a pressure generation chamber of an ink jet recording head according to another embodiment of the present invention.

FIG. 12 is a schematic view 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 14 reservoir 18 nozzle plate 50 elastic film 60 lower electrode film 70 piezoelectric film 80 upper electrode 90 insulator layer 90a contact hole 105 holder 100 lead electrode 110 cap member 112 recess 113 through hole 114 possible Flexure

Claims (12)

[Claims] 1. A flow path forming substrate having, on one surface thereof, a row of pressure generating chambers which are communicated with a nozzle opening and partitioned by a plurality of partition walls, and having an elastic film constituting a part of the pressure generating chambers on the other surface. In the ink jet recording head having a piezoelectric vibrator in a region corresponding to the pressure generating chamber, a space is provided that is joined to the piezoelectric vibrator side of the flow path forming substrate and does not hinder its movement. An ink jet recording head comprising a cap member for sealing the space in a state, and a pressure change absorbing means for absorbing a pressure change in the space of the cap member. 2. An ink jet recording head according to claim 1, wherein said pressure change absorbing means is an elastic porous member provided in said cap member. 3. The pressure change absorbing means according to claim 1, wherein the pressure change absorbing means is a flexible portion provided on the cap member, and a space in the cap member faces the outside via the flexible portion. An ink jet recording head. 4. The pressure generating chamber according to claim 1, further comprising a dummy pressure generating chamber to which ink is not supplied adjacent to the pressure generating chamber, wherein the pressure change absorbing unit is provided between the dummy pressure generating chamber and the cap member. An ink jet recording head, which is a flexible plate serving as a boundary with a space. 5. An ink jet recording head according to claim 4, wherein said flexible plate is made of at least said elastic film. 6. The ink jet recording head according to claim 1, wherein the entire cap member is made of a flexible material. 7. The method according to claim 6, wherein the flexible material is
An ink jet recording head comprising paper or aluminum coated with an inner surface. 8. An ink jet recording head according to claim 6, wherein said flexible material is joined to said flow path forming substrate by welding with aluminum. 9. The piezoelectric vibrator according to claim 1, wherein the flow path forming substrate is formed of a silicon single crystal substrate, the pressure generating chamber is formed by anisotropic etching, and each layer of the piezoelectric vibrator is formed. And an ink jet recording head formed by a lithography method. 10. The flow path forming substrate according to claim 1, wherein a reservoir communicating with the pressure generating chamber is defined in the flow path forming substrate, and a nozzle plate having the nozzle opening is joined thereto. Inkjet recording head. 11. The flow channel forming substrate according to claim 1, wherein a common ink chamber for supplying ink to the pressure generating chamber and a flow communicating the pressure generating chamber and the nozzle opening are provided in the flow path forming substrate. An ink jet recording head, wherein a flow path unit forming a path is joined to the ink jet recording head. 12. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.