JP2001347674A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head which can be manufactured easily while enhancing the yield. SOLUTION: Forward end of a common inner electrode 32 is exposed to the forward end face of a drive oscillator 29 and a diaphragm 9 is imparted with conductivity and conducted with the common inner electrode 32. Individual electrodes 33 are exposed, at the base end thereof, to the base end face of a piezoelectric oscillator and the base end face serves as a contact part with the individual electrodes 33. Potentials are applied individually from the contact part to the individual electrodes 33 and a common potential is applied to the common inner electrode 32 through the diaphragm 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which individual internal electrodes and common internal electrodes are alternately laminated with a piezoelectric body interposed therebetween, and a plurality of piezoelectric vibrators which can expand and contract in a direction perpendicular to the laminating direction. The present invention relates to an ink jet type recording head having piezoelectric vibrator units arranged in a line.

[0002]

2. Description of the Related Art As a piezoelectric vibrator, a d31 mode piezoelectric vibrator which causes displacement in a direction perpendicular to the laminating direction of a piezoelectric body or an electrode is known. A piezoelectric vibrator provided with the d31 mode piezoelectric vibrator is known. There is an ink jet type recording head configured using a unit.

The above-described piezoelectric vibrator unit is manufactured, for example, by the following procedure. First, a common internal electrode and individual internal electrodes are alternately laminated with a piezoelectric body interposed therebetween to produce a plate-like laminate, and an electrode layer serving as a common external electrode and an electrode serving as an individual internal electrode are formed on the surface of the laminate. A layer is formed to conduct to the common internal electrode and the individual internal electrode between the layers. afterwards,
The base end side of the laminated body on which the external electrodes are formed is joined to a fixed substrate, and the laminated body is cut into an extremely thin width using a wire saw, a dicing saw, or the like. Thus, a piezoelectric vibrator unit having a plurality of needle-shaped piezoelectric vibrators arranged in a row is obtained. In this piezoelectric vibrator unit, a contact portion with a signal cable is provided on a side surface opposite to a bonding surface of the fixed substrate. For this reason, the common external electrode and the individual external electrode have two surfaces, the tip surface of the vibrator and the side surface on the contact portion side, and
It is formed in a series over two surfaces, the base end surface of the vibrator and the side surface on the contact portion side.

[0004]

However, this d
A piezoelectric vibrator unit having a 31-mode piezoelectric vibrator has a problem that it is difficult to form external electrodes.
In other words, in order to prevent disconnection at the edges of the above two surfaces and to ensure the conduction of the external electrodes, the external electrode layers are formed thick, or the external electrode layers are deposited while rotating in a sputtering tank. Had to be done. For this reason,
The formation of the external electrodes is troublesome and contributes to an increase in cost.

Also, when assembling the vibrator unit, there is a problem that the external electrode is disconnected simply by touching the edge portion of the piezoelectric vibrator to another component or the like. Was.

There is also a recording head provided with a plurality of piezoelectric vibrator units. In this recording head, a signal cable is connected to each piezoelectric vibrator unit, and after each signal cable is further assembled on a relay board, Since the wiring configuration is such that the wiring is routed to the main control circuit board, the wiring connection is complicated and there is a problem that it is difficult to rationalize the work.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ink jet recording head which is easy to manufacture and can improve the yield.

[0008]

Means for Solving the Problems The present invention has been proposed to achieve the above object. According to the present invention, an individual internal electrode and a common internal electrode are sandwiched by a piezoelectric body. A piezoelectric vibrator unit in which a plurality of piezoelectric vibrators which are configured by being alternately laminated and which can expand and contract in the direction perpendicular to the laminating direction is provided, and a distal end surface of the piezoelectric vibrator is joined to be displaced by expansion and contraction of the piezoelectric vibrator. In the ink jet recording head having a vibrating plate, the end of the common internal electrode is exposed to the front end surface of the piezoelectric vibrator, and the vibrating plate is provided with conductivity to electrically connect the common internal electrode and the vibrating plate. Then, the base end of the individual internal electrode is exposed to the base end surface of the piezoelectric vibrator, and the base end surface is used as a contact portion with the individual internal electrode. From the contact portion, an individual potential is applied to the individual internal electrode, and the common potential is applied through the diaphragm. Apply common potential to internal electrodes An ink jet recording head is characterized by being configured to.

According to a second aspect of the present invention, there is provided the ink jet recording head according to the first aspect, wherein the outermost layer of the piezoelectric vibrator in the stacking direction is formed of a piezoelectric material.

According to a third aspect of the present invention, there is provided an ink jet recording head according to the first or second aspect, wherein a tip end surface of the piezoelectric vibrator and the diaphragm are joined by a conductive adhesive. It is.

According to a fourth aspect of the present invention, there is provided the ink jet recording head according to the third aspect, wherein the conductive adhesive is a conductive paste.

According to a fifth aspect of the present invention, there is provided the ink jet recording head according to the fourth aspect, wherein the conductive paste is an anisotropic conductive paste.

According to a sixth aspect of the present invention, there is provided the ink jet recording head according to the third aspect, wherein the conductive adhesive is an anisotropic conductive film having an adhesive property.

According to a seventh aspect of the present invention, there is provided the ink jet recording head according to any one of the first to sixth aspects, wherein the diaphragm is formed by electroforming.

According to an eighth aspect of the present invention, the diaphragm is
2. A vibration plate base having an island portion pressed by a piezoelectric vibrator provided on a resin thin plate, and a conductive film formed on a surface of the diaphragm base. Item 7. An ink jet recording head according to any one of Items 6.

According to a ninth aspect of the present invention, in the piezoelectric vibrator unit, a dummy vibrator which is not involved in the ejection of ink droplets is arranged in line with the piezoelectric vibrator.
A series of internal connection electrodes whose tips are exposed on the tip end face of the vibrator and whose base end is exposed on the base end face of the vibrator are provided. By joining the tip end face of the dummy vibrator to the diaphragm, The common internal electrode of the transducer is electrically connected, a contact portion with the internal connection electrode is formed on the base end surface of the dummy vibrator, and a common potential is applied to the common internal electrode from the contact portion. An inkjet recording head according to any one of claims 1 to 8.

According to a tenth aspect of the present invention, there is provided the ink jet recording head according to the ninth aspect, wherein the dummy vibrator has a width larger than a width of the piezoelectric vibrator.

In a preferred embodiment, the piezoelectric vibrator unit includes a fixing member joined to a side surface of the base end portion of the vibrator, and a contact portion on the base end side of the vibrator is located outside the edge of the fixing member. The inkjet recording head according to any one of claims 1 to 10, wherein the vibrator and the fixing member are joined in this state.

Here, "the area outside the edge of the fixing member"
Is a range including the same position as the edge of the fixing member and a position outside the edge.

According to a twelfth aspect of the present invention, in the piezoelectric vibrator unit, the piezoelectric vibrator unit includes a fixing member joined to a side surface of the base end portion of the vibrator, and the plurality of piezoelectric vibrators are fixed independently of each other. The ink jet recording head according to any one of claims 1 to 11, wherein the ink jet recording head is joined to the ink jet recording head.

According to a thirteenth aspect of the present invention, there is provided the ink jet printer according to any one of the first to twelfth aspects, wherein the contact part is constituted by a contact terminal formed so as to cover an end face of the vibrator. It is a type recording head.

According to the present invention, a plurality of the piezoelectric vibrator units are provided, and the vibrating plate is electrically insulated for each piezoelectric vibrator unit. An inkjet recording head according to any one of the above.

According to a fifteenth aspect of the present invention, there is provided the ink jet recording head according to any one of the first to fourteenth aspects, wherein the common potential is a ground potential.

According to a sixteenth aspect of the present invention, there is provided the ink jet recording head according to the fifteenth aspect, wherein the diaphragm and the nozzle plate are electrically connected.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment will be described. Here, FIG. 1 is a sectional view showing an ink jet recording head. The illustrated recording head 1 has a case 2
And a flow path unit 3 joined to the end face of the case 2
And a piezoelectric vibrator unit 4 housed inside the case 2.

The case 2 has a block shape in which an accommodation chamber 5 for accommodating the piezoelectric vibrator unit 4 is formed, and is formed of, for example, a resin material. The accommodation chamber 5 is formed so as to penetrate the case 2 from the joint surface with the flow channel unit 3 to the opposite surface.

The flow channel unit 3 has a configuration in which a nozzle plate 8 is bonded to one surface of a flow channel forming substrate 7 and a vibration plate 9 is bonded to the other surface of the flow channel forming substrate 7.

The nozzle plate 8 is a plate member in which a plurality of nozzle openings 10 are formed in a row at a predetermined pitch corresponding to the dot formation density, and is made of, for example, a conductive metal material, in this embodiment, a stainless steel plate. It is composed.

The flow path forming substrate 7 is formed of, for example, a silicon wafer. The silicon wafer is divided into a predetermined pattern by etching, and a plurality of pressure chambers 12... A common reservoir 11 and a plurality of ink supply passages 13 communicating from the reservoir 11 to the pressure chambers 12 are appropriately formed. The reservoir 11 is provided with a connection port connected to the ink supply pipe 6, and the ink supplied from the ink supply pipe 6 flows into the reservoir 11 through the connection port.

The vibration plate 9 is a member constituting a part of a partition wall of the pressure chamber 12, and also functions as a part of a common electrode for a driving vibrator 29 described later. The vibration plate 9 is formed of a thin conductive plate material having elasticity, and a portion corresponding to each pressure chamber 12 is protruded in a block shape to form an island portion 16 (island portion), and a thin wall surrounding the island portion 16. This portion is referred to as an elastic portion 17. Then, a wiring 25 is electrically connected to the diaphragm 9. The wiring 25 is grounded.

In the present embodiment, the diaphragm 9 is formed by electroforming a metal (eg, nickel). For example, a thin metal plate having a predetermined thickness (for example, about 1 micron) is formed by the first electroforming, and a resist having a predetermined pattern is formed on the metal flat plate. After the resist is formed, the second electroforming is performed on the flat metal plate on which the resist is formed, and the island portions 16 are arranged in a row. The island portion 16 has a narrow width in the direction in which the pressure chambers 12 are arranged, and has an elongated shape in a direction perpendicular to the arrangement direction. After the island portions 16 are formed, the resist is removed to obtain the diaphragm 9.

The piezoelectric vibrator unit 4 is schematically composed of a vibrator group 21 and a fixed substrate 22, as shown in FIG.

The vibrator group 21 includes a driving vibrator 29 (corresponding to a piezoelectric vibrator in the present invention) which can be involved in the ejection of ink droplets and a dummy vibrator 2 which is not involved in the ejection of ink droplets.
8, 28. The dummy vibrators 28, 28 are formed one at each end in the vibrator row direction, and a plurality (for example, 96) are provided between the dummy vibrators 28, 28.
Are arranged. The width of the dummy vibrator 28 in the column setting direction is sufficiently larger than the width of the driving vibrator 29. When the dummy vibrator 28 is made wide in this way, the dummy vibrator 28 can be made robust, and the drive vibrator 29 can be protected from impact. For example,
When housing the piezoelectric vibrator unit 4 in the case 2, even if the vibrator group 21 is brought into contact with the case 2,
The drive oscillator 29 can be prevented from being damaged.

The fixed substrate 22 is a kind of a fixed member in the present invention, and is joined to a side surface of a base end portion (hereinafter, referred to as a fixed end portion 21b) of the vibrator group 21. That is, the vibrators 28 and 29 have their free ends 21 a
It is joined to the fixing member 22 in the state of a so-called cantilever projecting outward from the edge of the fixing member 22. In the present embodiment, the fixed substrate 22 is formed of a stainless steel plate having a thickness of about 1 to 2 mm. However, if the fixed substrate 22 can support the vibrators 28 and 29 constituting the vibrator group 21, the fixed substrate 22 may be formed of a stainless steel plate. It is not limited.

The piezoelectric vibrator unit 4 includes the vibrator group 2
1 (that is, the end of the free end 21 a) is housed in the housing chamber 5 with the fixed substrate 22 facing the opening on the side of the flow path unit 3, and the fixed substrate 22 is bonded to the inner wall of the housing chamber 5 by bonding or the like. It is fixed. Then, in this housed state, the distal end surface 42 (see FIG. 3) of the driving vibrator 29 is joined to the corresponding island portion 16 of the diaphragm 9 with an adhesive or the like.

Next, the driving oscillator 29 and the dummy oscillator 28 will be described in detail with reference to FIGS. Note that the dummy vibrator 28 in the present embodiment is different in that the width is wider than the width of the driving vibrator 29, but the other configuration is the same as that of the driving vibrator 29. Therefore, the following description will be made with respect to the driving vibrator 29.

The driving vibrator 29 includes an individual internal electrode 33
And the common internal electrode 32 are alternately stacked with the piezoelectric body 31 interposed therebetween. An electric field due to the potential difference between the individual internal electrode 33 and the common internal electrode 32 acts on the piezoelectric body 31 so that the stacking direction is The so-called d that expands and contracts in the direction
This is a 31-mode piezoelectric vibrator. Here, the electrode layers such as the individual internal electrode 33 and the common internal electrode 32 are formed of a highly conductive metal material such as silver-palladium, and the piezoelectric body 31 is formed of a piezoelectric material such as lead zirconate titanate. Is done.

The common internal electrode 32 is connected to the free end 21
are formed in a series from the boundary between the fixed end 21a and the fixed end 21b toward the free end 21a, and the tip is linearly exposed on the tip end surface 42 of the driving vibrator 29. On the other hand, the individual internal electrodes 33 are formed in a series from the end surface (base end surface) 43 on the fixed end portion 21 b side to a little before the front end surface 42, and the base end is linearly exposed at the base end surface 43. . Further, an internal electrode 34 is formed at the same lamination position as the common internal electrode 32 and at the fixed end 21b. This internal electrode 34
Is electrically insulated by being separated from the common internal electrode 32, and its base end is linearly exposed at the base end face 43. The vibrator tip surface 42 forms a contact portion with the common internal electrode 32, and the vibrator base end surface 43 forms a contact portion with the individual internal electrode 33. Note that, as shown in FIG. 3, the transducer base end surface 43 is slightly outside the edge of the fixed substrate 22 (reference d).
).

The common internal electrodes 32 and the individual internal electrodes 33 overlap (overlap) in the free end 21a, and the piezoelectric body 31 is deformed within the overlap region L. The resulting electric field occurs. Therefore, the overlap region L becomes an active region for expanding and contracting the driving oscillator 29, and the free end 21a expands and contracts in the oscillator longitudinal direction. Further, in the present embodiment, the outermost layer in the stacking direction in the driving vibrator 29 is constituted by the piezoelectric body 31. With this configuration, the area of the electrode exposed on the side surface of the vibrator can be reduced, so that the internal electrodes 32 and 33 are hardly damaged, and the reliability of the piezoelectric vibrator unit 4 can be improved.

The piezoelectric vibrator unit 4 having the above configuration
Is manufactured, for example, by the following procedure. That is, a first piezoelectric body 31 having an electrode layer serving as a common internal electrode 32 and an internal electrode 34 formed on one side and a second piezoelectric body 31 having an electrode layer serving as an individual internal electrode 33 formed on one side are connected to each other. Are laminated alternately so that they do not face each other, and then fired to produce a plate-shaped laminate. Then, the fixed substrate 22 is joined to the side surface of the base end portion of the plate-like stacked body with an adhesive or the like. After the fixed substrate 22 is bonded, the plate-like laminate is cut by a wire saw, a dicing saw, or the like, and the dummy vibrators 28, 28
And the driving vibrator 29. At the time of this cutting, a groove 39 that reaches the fixed substrate 22 from the surface opposite to the fixed substrate side is formed, and the vibrators 28 and 29 are cut so as to be completely separated. Thus, each of the oscillators 28 and 29
Are formed by cutting the grooves 39 down to the fixed substrate 22, so that they are individually and independently joined on the fixed substrate 22.

As described above, in the piezoelectric vibrator unit 4, it is not necessary to form an electrode layer serving as an external electrode on the surface of the laminate when producing the plate-like laminate. For this reason,
The step of forming the external electrode layer, which was conventionally troublesome, can be omitted, the production efficiency can be improved, and the cost of the product can be reduced. Further, conventionally, the reliability of conduction at the edge portion of the external electrode layer was low and the yield was accordingly low. However, in the piezoelectric vibrator unit 4, the external electrode layer does not need to be provided, and the external electrode layer is not provided. Even if it is provided, it is not necessary to guarantee the conductivity of the edge portion, so that the yield can be improved, and the cost of the product can also be reduced in this regard.

The piezoelectric vibrator unit 4 is housed and fixed in the housing chamber 5 of the case 2 as described above. At this time, the distal end surface 42 of the driving vibrator 29 and the island portion 16 of the diaphragm 9 are electrically connected. Bonding with the adhesive 20. As a result, the common internal electrode 32 and the diaphragm 9 conduct, and as a result, the potential level of the common internal electrode 32 becomes the ground potential which is the potential level of the wiring 25. In this case, the common internal electrodes 32 of all the driving vibrators 29 have a common potential (ground potential) through the diaphragm 9. Various materials such as a paste or a film can be used as the conductive adhesive 20. For example, conductive paste, anisotropic conductive paste (A
CP) or an anisotropic conductive film (ACF) having adhesiveness is preferably used. When the paste-like conductive adhesive 20 is used, the connection between the common internal electrode 32 and the diaphragm 9 can be reliably performed. On the other hand, when the film-shaped conductive adhesive 20 is used,
The connection work between the common internal electrode 32 and the diaphragm 9 can be easily performed.

On the other hand, a wiring pattern of the flexible cable 24 (a kind of drive signal supply member) is connected to the vibrator base end surface 43 serving as a contact portion of the individual internal electrode 33 by soldering or the like. A plurality of the wiring patterns are provided corresponding to the respective driving vibrators 29. As described above, the individual internal electrodes 33 are exposed on the base end surface 43 to form contact points, and the flexible cable 24 is connected to the contact points. Therefore, the electrical connection between the driving vibrator 29 and the flexible cable 24 can be easily performed. It can be carried out.

Further, as described above, the vibrator base end face 4
3 protrudes outward from the edge of the fixed substrate 22 by the amount indicated by the symbol d, so that the base end surface 43 and the flexible cable 24 can be easily brought into contact with each other without being obstructed by the fixed substrate 22. Thereby, the connection reliability between the base end surface 43 and the flexible cable 24 can be improved. In addition, from the viewpoint of connection reliability, the same effect can be obtained if the base end face 43 is at the same position (that is, flush) with the edge of the fixed substrate 22. Therefore, it is preferable that the base end surface 43 as the contact portion of the individual internal electrode 33 be located outside the edge of the fixed substrate 22.

When a drive signal (that is, an individual potential) is supplied to the individual internal electrodes 33 through the flexible cable 24, a connection between the individual internal electrodes 33 having an individual potential and the common internal electrodes 32 having a common potential (ground potential in this embodiment) is generated. Generates a potential difference, and the piezoelectric material 31 in the active region L is generated according to the potential difference.
Is mechanically displaced, and the free end 21a expands and contracts in the element longitudinal direction. Then, with the expansion and contraction of the driving vibrator 29, the island portion 16 and the elastic portion 17 of the diaphragm 9 are displaced, and the corresponding pressure chamber 12 expands or contracts. The change in the volume of the pressure chamber 12 causes a pressure change in the ink in the pressure chamber 12.
The ink droplet is ejected from 0. For example, the pressure chamber 12 is once expanded and then contracted.

The common potential applied to the common internal electrode 32 is not limited to the ground potential but may be set as appropriate. However, it is preferable to set the common potential to the ground potential as in this embodiment. This is for the following reason. That is, since the vibration plate 9 is in direct contact with the ink, if the vibration plate 9 is charged, this charging may adversely affect the ink in the pressure chamber 12. By setting the common potential to the ground potential, it is possible to prevent adverse effects on ink due to charging.

When the ink is conductive, the diaphragm 9 and the nozzle plate 8 conduct through the ink in the pressure chamber 12 when the pressure chamber 12 is filled with the ink. Therefore, when the potential level of the diaphragm 9 is set to the ground potential, the potential level of the nozzle plate 8 is also set to the ground potential, and the nozzle plate 8 is hardly charged. This can prevent dust such as paper dust from adhering to the surface of the nozzle plate 8. As a result, the surface of the nozzle plate 8 can be kept clean, and it is possible to prevent stains on the recording paper caused by the attached dust absorbing and solidifying the ink mist.

In this embodiment, the vibration plate 9 and the nozzle plate 8 are electrically connected to each other through the ink. However, the vibration plate 9 and the nozzle plate 8 may be directly connected to each other by wiring or the like. With this configuration, even when non-conductive ink is used, the potential level of the nozzle plate 8 becomes the ground potential, and dust such as paper dust can be prevented from adhering to the surface of the nozzle plate 8.

As described above, in this embodiment, the tip of the common internal electrode 32 is exposed on the tip end face 42 of the driving vibrator 29, and the tip end face 42 is attached to the conductive diaphragm 9 (island portion 16). By joining, the diaphragm 9 and the common internal electrode 32 are conducted. On the other hand, the base end of the individual internal electrode 33 is exposed on the base end surface 43 of the driving vibrator 29, and the flexible cable 24 is joined to the base end surface 43.
The wiring 9 is electrically connected to the vibration plate 9, the vibration plate 9 and the common internal electrode 32 are set to the ground potential, and a drive signal is supplied to the individual internal electrodes 33 through the wiring pattern of the flexible cable 25. With this configuration, it is not necessary to provide an external electrode on the side surface of the vibrator, and as a result,
Production efficiency and yield can be improved, and product cost can be reduced. Further, even if an external electrode is provided on the side surface of the vibrator, it is not necessary to secure conduction at the edge portion, so that manufacturing is facilitated and the same operation and effect can be obtained.

In the first embodiment described above, the tip of the common internal electrode 32 is exposed at the transducer tip face 42, and the transducer tip face 42 is directly joined to the diaphragm 9. Similarly, the base end of the individual internal electrode 33 is exposed on the transducer base end face 43, and the transducer base end face 43 is directly joined to the flexible cable 24. However, the present invention is not limited to this configuration. . For example, the transducer tip surface 42
(That is, the contact portion with the common internal electrode 32) and the vibrator base end surface 43 (that is, the contact portion with the individual internal electrode 33)
May be provided with a contact terminal. Hereinafter, a second embodiment configured as described above will be described.

FIG. 4 shows a second embodiment of the present invention, and is a view for explaining the configuration of the piezoelectric vibrator unit 404. The piezoelectric vibrator unit 404 has a contact terminal 52 formed on the surface of the distal end surface 42 of each driving vibrator 29 so as to cover the distal end surface 42 and a contact terminal 52 formed on the surface of the proximal end surface 43 so as to cover the proximal end surface 43. The terminal 53 is formed. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

The contact terminals 52 formed on the distal end surface 42 and the contact terminals 53 formed on the proximal end surface 43 are both formed of a conductive metal layer or the like. These contact terminals 5
The contact terminal 2 and the contact terminal 53 are a kind of contact portion in the present invention. The contact terminal 52 is electrically connected to the common internal electrode 32, and the contact terminal 53 is electrically connected to the individual internal electrode 33. The contact terminals 52 are joined in a state of contacting the island portions 16 of the diaphragm 9, and the contact terminals 53 are joined in a state of contacting the wiring pattern of the flexible cable 24.

In this configuration, the area of the conductive portion on the transducer end face 42 and the transducer base face 43 is set to the first area.
It is provided wider than the piezoelectric vibrator unit 4 of the embodiment. That is, in the above-described piezoelectric vibrator unit 4, the internal electrodes 32, 33, and 34 are linearly exposed on the distal end surface or the base end surface. It is formed so that it may cover.
Accordingly, electrical connection between the common internal electrode 32 and the diaphragm 9 and between the individual internal electrode 33 and the flexible cable 24 can be more reliably performed, and reliability can be improved.

Further, in this configuration, the contact terminals 52, 5
Since each of the surfaces forming 3 is one plane, there is no need to consider the conductivity at the edge portion of the vibrator. Therefore, sufficient reliability can be obtained even if the thickness of the contact terminals 52 and 53 is reduced. The contact terminal 52 and the contact terminal 53 can be formed not only by sputtering, but also by a simple method such as screen printing since it is sufficient to form them on one surface.

Since the contact terminal 52 and the contact terminal 53 are provided, the contact terminal 52 and the contact terminal 53 are provided.
Can also be used as a contact for inspection. That is,
Since these contact terminals 52 and 53 have a sufficient area for inspection, they can be used as contact terminals for contacting the inspection probe. For this reason,
Various characteristics tests can be performed on the piezoelectric vibrator unit 4 alone before being assembled into the recording head 1. By performing this inspection, only non-defective products that have been subjected to the unit inspection can be brought into the assembling process, and the production can be rationalized.

Although the recording head 1 of each of the above embodiments has a single piezoelectric vibrator unit 4, the present invention is also applicable to a recording head having a plurality of piezoelectric vibrator units. Is what is done. Hereinafter, a third embodiment configured as described above will be described. Here, FIG.
FIG. 7 is a cross-sectional view of an ink jet recording head 501 according to a third embodiment.

This recording head 501 has one case 5
02, two piezoelectric vibrator units 504 and 504 are arranged and stored in a back-to-back state. Accordingly, two rows of nozzles are formed in the nozzle plate 508, and two sets of the pressure chambers 12 and the reservoirs 11 are provided. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The main differences between the third embodiment and the first embodiment are that two piezoelectric vibrator units 504 and 504 are arranged in a case 502, the configuration of the diaphragm 90, and the dummy vibration. This is the configuration of the slave 528 and the configuration of the flexible cable 524. Hereinafter, these differences will be mainly described.

The vibration plate 90 of this embodiment is provided with island portions 16... Pressed by the driving vibrator 29 on the thin plate 14 made of resin to serve as a diaphragm base material. Is formed on the surface of the conductive film 18.

More specifically, a stainless steel plate 15 is attached to an elastic thin plate 14 such as PPS (polyphenylene sulfide).
A portion corresponding to each pressure chamber 12 is etched in a ring shape on the stainless steel plate 15 side, and a block-shaped island portion 16 to which the distal end surface 42 of the driving vibrator 29 is joined in the ring. ... is formed. The island portions 16 are provided in a plurality of rows corresponding to the respective driving vibrators 29 of the piezoelectric vibrator unit 504 to form an island row. In the present embodiment, two island rows are provided corresponding to the two piezoelectric vibrator units 504 and 504, respectively, and the conductor film 18 covers the surface of each island row in a series.

The conductor film 18 has a band shape long in the direction of the island row, and both ends of the conductor film 18 are the dummy vibrator 528,
528 (see FIG. 6) is extended to a position where the tip of the 528 contacts. The conductor film 18 is electrically insulated for each of the two island section rows. Therefore, this diaphragm 90
Is a configuration in which each of the piezoelectric vibrator units 504 and 504 is electrically insulated. The conductor film 18 forms, for example, an electrode layer on the entire surface of the vibrator base material (14, 16) on the island portion side, and then forms a conductive film formed on the surface of the resin thin plate on both sides of the island row. It is produced by removing the body film 18.

The structure of the piezoelectric vibrator unit 504 is substantially the same as that of the first embodiment shown in FIG. That is,
As shown in FIG. 6, the vibrator group 21 is roughly composed of a vibrator group 21 and a fixed substrate 22, and the vibrator group 21 includes dummy vibrators 528, 528 formed one at each end in the vibrator row direction.
, And a plurality of driving vibrators 29 arranged between these dummy vibrators 528. The driving vibrator 29 has the same configuration as the driving vibrator 29 of the first embodiment, and as shown in FIG. 7A, a common internal portion provided substantially over the entire free end portion 21a. The configuration is such that the electrodes 32 and the individual internal electrodes 33 provided in series from the transducer base end face 43 to slightly before the transducer tip face 42 are alternately laminated with the piezoelectric body 31 interposed therebetween.

On the other hand, the dummy vibrators 528 and 528 have a different electrode structure from the dummy vibrator 28 of the first embodiment. That is, as shown in FIG.
For each layer between 1 and 31, the tip is the transducer tip surface 42 '.
And a series of internal connection electrodes 35 whose base ends are exposed to the transducer base end surface 43 '. The internal connection electrode 35 is an electrode for electrically connecting the distal end surface 42 ′ and the base end surface 43 ′ of the dummy vibrator 528.
Then, the transducer distal end surface 42 ′ and the base end surface 43 ′
Constitutes a contact portion with the internal connection electrode 35. And also in this embodiment, the dummy vibrators 528, 528
Is sufficiently larger than the width of the driving vibrator 29.

The piezoelectric vibrator unit 50 having the above configuration
4 is produced, for example, by the following procedure. That is, FIG.
As shown in (A), the free end 21a and the fixed end 21b
A first piezoelectric body 31 having a first conductive film pattern 61 having a strip-shaped deficient portion 60 at a portion corresponding to the boundary between the first piezoelectric body 31 and the free end, as shown in FIG. Part 21
A second piezoelectric body 31 having a second conductive film layer pattern 62 having a rectangular cutout portion 63 at a portion corresponding to the tip of a is alternately laminated on one surface, and then fired to form a plate-like laminate. Make a body.

Then, the fixed substrate 22 is bonded to the side surface of the base end portion of the plate-like stacked body with an adhesive or the like. After the fixed substrate 22 is joined, the portions of the plate-like laminate shown by the dashed lines in FIG. 8 are cut by a wire saw, a dicing saw, or the like, and the dummy vibrators 528, 528 and the driving vibrators 29 are formed.
And cut it out. Also at the time of this cutting, similarly to the first embodiment, the groove 39 that reaches the fixed substrate 22 from the surface opposite to the fixed substrate side is formed, and the vibrators 528 and 29 are cut so as to be completely separated.

The piezoelectric vibrator unit 504 is accommodated and fixed in the accommodating chamber 5 of the case 2. At this time, the distal end face 42 of the driving vibrator 29 and the conductive film 18 on the island surface
Are bonded by a conductive adhesive 20. Similarly, the distal end surface 42 ′ of the dummy vibrator 528 and the conductor film 18 are joined by the conductive adhesive 20. As a result, the common internal electrode 32 and the conductor film 18 conduct, and the internal connection electrode 35 and the conductor film 18 conduct. That is, the common internal electrode 32 and the internal connection electrode 35 conduct through the conductor film 18.

The wiring pattern of the flexible cable 524 is connected to the base end face 43 of the driving vibrator 29 and the base end face 43 'of the dummy vibrator 528. The flexible cable 524 is provided with a wiring pattern on the common electrode side for applying a potential to the common internal electrode 32 and a wiring pattern on the individual electrode side for applying a potential to the individual internal electrode 33. This wiring pattern is electrically connected to the exposed electrode on the base end face 43 ′ of the dummy vibrator 528, and the wiring pattern on the individual electrode side is electrically connected to the exposed electrode on the base end face 43 of the driving vibrator 29. In the flexible cable 524, the wiring pattern on the individual electrode side and the wiring pattern on the common electrode side are separately formed for each of the two piezoelectric vibrator units 504 and 504.

As described above, in this embodiment, the dummy vibrators 528 are provided with the internal connection electrodes 35 extending from the distal end surface 42 'to the base end surface 43'. Common internal electrode 32 and internal connection electrode 3
5 is conducted. Then, a wiring pattern on the common electrode side of the flexible cable 524 is connected to the base end face 43 ′ (that is, the contact portion), and a ground potential (common potential) is supplied from the base end face 43 ′ to the common internal electrode 32. For this reason,
The supply of the drive signal and the ground potential to the vibrator group 21 can be performed only on the vibrator base end faces 43 and 43 ', and wiring work is easy. Then, the flexible cable 5 for the two piezoelectric vibrator units 504 and 504 are sequentially arranged.
24, and need only be electrically connected, eliminating the need for a conventional relay board.
24 can be simplified, the connection work can be facilitated, and the production efficiency can be improved. Further, the dummy oscillator 52
Since the width of 8 is formed sufficiently wider than the width of the driving vibrator 29, the internal connection electrode 35 can also be formed to be wide. Thereby, the electric resistance value of the internal connection electrode 35 can be reduced, and more current can flow.

The conductor film 18 to which the vibrator tip surface 42 is fixed is electrically insulated for each of the piezoelectric vibrator units 504 and 504.
As for the wiring 24, the wiring pattern on the common electrode side is formed separately and independently, so that the path through which the current flows differs for each of the piezoelectric vibrator units 504 and 504. Therefore, during the driving operation of the recording head 1, the current of one piezoelectric vibrator unit 504 is changed to the other piezoelectric vibrator unit 50.
4 can be eliminated.

In the vibrator group 21, the direction of the current flowing through the driving vibrators 29 and the dummy vibrators 528, 5
The direction of the current flowing through the inside 28 is opposite. Thereby, the inductance can be reduced, and the effect of electromagnetic induction can be reduced. Similarly, in the flexible cable 524,
The wiring pattern on the common electrode side and the wiring pattern on the individual electrode side can be brought close to each other in a so-called pair state.
Since the direction of the current flowing in the wiring pattern on the common electrode side and the direction of the current flowing in the wiring pattern on the individual electrode side are also opposite, the effect of electromagnetic induction can be reduced even in the flexible cable 524.

[0071]

As described above, according to the present invention,
The following effects are obtained. That is, while exposing the distal end of the common internal electrode to the distal end surface of the piezoelectric vibrator, imparting conductivity to the diaphragm to make the common internal electrode and the diaphragm conductive, and connecting the base end of the individual internal electrode to the piezoelectric vibrator The base end face is exposed to the base end face to form a contact portion with the individual internal electrode, and the individual potential is applied to the individual internal electrode from the contact portion, and the common potential is applied to the common internal electrode through the diaphragm. The diaphragm conducts to the common internal electrode of each piezoelectric vibrator and also functions as a part of the common electrode. Therefore, it is not necessary to form an electrode layer serving as an external electrode on the surface of the piezoelectric vibrator. For this reason, the step of forming the external electrode layer, which has conventionally been troublesome, can be omitted, and the production efficiency can be improved. In addition, since no external electrode layer is provided, defects due to damage to the external electrodes can be eliminated, and the yield can be improved.

When the outermost layer of the piezoelectric vibrator in the laminating direction is made of a piezoelectric material, the exposed area of the internal electrode is reduced, so that the internal electrode is hardly damaged. as a result,
The reliability of the piezoelectric vibrator unit can be improved.

Further, when the distal end surface of the piezoelectric vibrator and the vibration plate are joined by a conductive adhesive, the joining and conduction can be performed at the same time, so that the work efficiency in manufacturing can be improved, and the conduction state can be improved. The piezoelectric vibrator and the diaphragm can be securely joined while maintaining the same.

When the diaphragm is formed by electroforming, a diaphragm having conductivity can be easily manufactured.

Further, the diaphragm is composed of a diaphragm base member having an island portion pressed by a piezoelectric vibrator provided on a thin resin plate, and a conductive film formed on the surface of the diaphragm base member. In this case, conductivity can be selectively imparted to an arbitrary region on the diaphragm surface.

Further, the dummy vibrator is provided with a series of internal connection electrodes having a front end exposed on the front end face of the vibrator and a base end exposed on the base end face of the vibrator. By connecting the internal connection electrode to the common internal electrode of the piezoelectric vibrator, a contact portion with the internal connection electrode is formed on the base end surface of the dummy vibrator, and a common potential is applied from the contact portion to the common internal electrode. When configured to grant
The contact portion for applying a common potential and the contact portion for applying an individual potential are both located on the transducer base end face, and electrical connection with the wiring member can be performed only on the transducer base end face side,
Work is easy. Further, since the direction of the current flowing in the piezoelectric vibrator and the direction of the current flowing in the dummy vibrator are opposite, the inductance can be reduced and the influence of electromagnetic induction can be reduced. Further, in a configuration including a plurality of piezoelectric vibrator units, wiring to the plurality of piezoelectric vibrator units can be performed by one wiring member, so that the configuration can be simplified and manufacturing efficiency can be improved.

Further, when the vibrator and the fixed member are joined with the contact portion on the base end side of the vibrator positioned outside the edge of the fixed member, the electric connection between the wiring member and the vibrator is made. Can be performed easily and reliably.

In the case where the contact portion is constituted by a contact terminal formed so as to cover the end face of the vibrator, the reliability of the electrical connection can be improved and the inspection of the piezoelectric vibrator unit alone can be performed. It is possible and rationalization of production can be achieved.

Further, a plurality of piezoelectric vibrator units are provided,
When the diaphragm is electrically insulated for each piezoelectric vibrator unit, the current of one piezoelectric vibrator unit does not easily interfere with the current of the other piezoelectric vibrator unit during the driving operation, and stable operation is achieved. Can be realized.

When the common potential is set to the ground potential, the potential level of the diaphragm becomes the ground potential, so that the diaphragm can be prevented from being charged.

When the diaphragm and the nozzle plate are electrically connected, the nozzle plate can be prevented from being charged and its surface can be kept clean.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an ink jet recording head according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the piezoelectric vibrator unit shown in FIG.

FIG. 3 is a cross-sectional view of the piezoelectric vibrator unit shown in FIG.

FIG. 4 is a sectional view of the piezoelectric vibrator unit according to the second embodiment.

FIG. 5 is a cross-sectional view of an ink jet recording head according to a third embodiment.

FIG. 6 is a perspective view of the piezoelectric vibrator unit shown in FIG.

7A and 7B are cross-sectional views of the piezoelectric vibrator unit shown in FIG. 5, wherein FIG. 7A is a cross-sectional view of a driving vibrator, and FIG. 7B is a cross-sectional view of a dummy vibrator.

8A is a plan view of an electrode layer of the piezoelectric vibrator unit shown in FIG. 5, FIG. 8A is a plan view of a first conductive film pattern forming a common internal electrode, and FIG. FIG. 4 is a plan view of a second conductive film pattern to be formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,501 Recording head 2,502 Case 3 Flow path unit 4,404,504 Piezoelectric vibrator unit 5 Storage chamber 6 Ink supply pipe 7 Flow path forming substrate 8,508 Nozzle plate 9,90 Vibration plate 10 Nozzle opening 11 Reservoir 12 Pressure chamber 13 Ink supply path 14 Elastic film 15 Stainless steel plate 16 Island part (island part) 17 Elastic part 18 Conductive film 20 Conductive adhesive 21 Vibrator group 22 Fixed substrate 21a Free end 21b Fixed end 24,524 Flexible cable (signal cable) 25 Wiring 28 Dummy vibrator 29 Driving vibrator 31 Piezoelectric body 32 Common internal electrode 33 Individual internal electrode 34 Internal electrode 35 Internal connection electrode 39 Groove 42 Tip surface 43 Base end surface 52 External common electrode 53 External individual electrode 60, 63 Defects 61 First conductive layer pattern 62 Second conductive layer pattern

Claims (16)

[Claims] 1. A piezoelectric vibrator unit comprising a plurality of piezoelectric vibrators which are formed by alternately laminating an individual internal electrode and a common internal electrode with a piezoelectric body interposed therebetween and which can extend and contract in a direction perpendicular to the laminating direction. A vibration plate displaced by the expansion and contraction of the piezoelectric vibrator, wherein the distal end surface of the piezoelectric vibrator is joined, and exposing the distal end of the common internal electrode to the distal end surface of the piezoelectric vibrator; Conductivity is imparted to the vibration plate to make the common internal electrode and the vibration plate conductive, exposing the base end of the individual internal electrode to the base end surface of the piezoelectric vibrator, and using the base end surface as a contact portion with the individual internal electrode. An ink jet recording head, wherein an individual potential is applied to the individual internal electrode from the contact portion, and a common potential is applied to the common internal electrode through the diaphragm. 2. The ink jet recording head according to claim 1, wherein the outermost layer of the piezoelectric vibrator in the laminating direction is formed of a piezoelectric material. 3. The ink jet recording head according to claim 1, wherein the tip surface of the piezoelectric vibrator and the vibration plate are joined by a conductive adhesive. 4. The ink jet recording head according to claim 3, wherein the conductive adhesive is a conductive paste. 5. The ink jet recording head according to claim 4, wherein said conductive paste is an anisotropic conductive paste. 6. The ink jet recording head according to claim 3, wherein the conductive adhesive is an anisotropic conductive film having an adhesive property. 7. The ink jet recording head according to claim 1, wherein said diaphragm is formed by electroforming. 8. The vibrating plate is composed of a vibrating plate base having an island portion pressed by a piezoelectric vibrator provided on a thin resin plate, and a conductive film formed on the surface of the vibrating plate base. The ink jet recording head according to any one of claims 1 to 6, wherein: 9. A piezoelectric vibrator unit, wherein a dummy vibrator not involved in the ejection of ink droplets is arranged in line with the piezoelectric vibrator, and a tip of the dummy vibrator is exposed on a front end face of the vibrator. A series of internal connection electrodes whose base ends are exposed on the base end surface of the vibrator are connected to each other, and the front end surface of the dummy vibrator is joined to the diaphragm to make the internal connection electrode and the common internal electrode of the piezoelectric vibrator electrically connected to each other. 9. The device according to claim 1, wherein a contact portion with an internal connection electrode is formed on a base end surface of the vibrator, and a common potential is applied from the contact portion to a common internal electrode. 10. 3. The ink jet recording head according to item 1. 10. The ink jet recording head according to claim 9, wherein the dummy vibrator has a width larger than a width of the piezoelectric vibrator. 11. The piezoelectric vibrator unit includes a fixing member joined to a side surface of a base end portion of the vibrator, and a contact portion on a base end side of the vibrator is located in a range outside the edge of the fixing member. 11. The ink jet recording head according to claim 1, wherein the vibrator and the fixing member are joined in a state. 12. The piezoelectric vibrator unit includes a fixing member joined to a side surface of a base end portion of the vibrator, and a plurality of piezoelectric vibrators are joined to the fixing member in an independent state. The ink jet recording head according to any one of claims 1 to 11, wherein: 13. The ink jet recording head according to claim 1, wherein said contact portion is constituted by a contact terminal formed so as to cover an end face of the vibrator. 14. The ink-jet apparatus according to claim 1, wherein a plurality of the piezoelectric vibrator units are provided, and the vibration plate is electrically insulated for each piezoelectric vibrator unit. Type recording head. 15. The ink jet recording head according to claim 1, wherein the common potential is a ground potential. 16. The ink jet recording head according to claim 15, wherein the diaphragm and the nozzle plate are electrically connected.