JP2002301817A - Diaphragm unit, ink jet recording head using the same and method of making the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm unit capable of improving the assembling property even when the width of the diaphragm is markedly small. SOLUTION: There is disclosed the diaphragm unit 4 wherein common inner electrodes 32 and individual inner electrodes 33 are alternately laminated with piezoelectric materials 31 therebetween to form a laminated body 41, common outer electrodes 37 communicating with the common inner electrodes 32 and individual outer electrodes 36 communicating with the individual inner electrodes 33 are formed on the surface of the laminated body 41, and the free end of the laminated body 41 is divided in a comb-shape to form each of diaphragms 29. The tip face of each diaphragm 29 is enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrator unit having a plurality of vibrators which expand and contract when supplied with a drive signal.
And an ink jet recording head using the same, and a method of manufacturing a vibrator unit.

[0002]

2. Description of the Related Art An ink jet recording head of this type includes, for example, a flow path unit in which a pressure chamber and a common ink chamber are formed, and a vibrator having a plurality of vibrators for changing the volume of the pressure chamber by expansion and contraction. Some have a unit.

[0003] The above-mentioned flow path unit includes, for example, a nozzle plate in which a plurality of nozzle openings are formed in a row, and a flow path formation in which an ink flow path is formed from a common ink chamber to a nozzle opening via a pressure chamber. A substrate and a diaphragm that is a part of a partition of the pressure chamber are provided, and these members are joined in a laminated state. Specifically, a nozzle plate is joined to one surface of the flow path forming substrate, and a diaphragm is joined to the other surface. The diaphragm has, for example, a double structure in which a resin film is laminated on a support plate, and a diaphragm portion having an island portion is formed by removing a portion of the support plate corresponding to the pressure chamber in an annular shape. The transducer unit is
A plurality of needle-shaped vibrators that can expand and contract by supplying a drive signal are provided, and these vibrators are arranged in a row in a direction orthogonal to the expansion and contraction direction.

The tip of the vibrator is bonded to the island of the diaphragm. At this time, the positioning of each vibrator is performed by dummy vibrators provided at both ends of the vibrator group. For example, the vibrator unit is guided to a predetermined mounting position while the dummy vibrator contacts the inner wall of the case.

[0005]

By the way, in the above-mentioned ink jet recording head, each vibrator has a size of 50 μm to 1 μm.
It is cut into an extremely thin needle shape of about 00 μm. Also, the bonding surface of the island portion with which each vibrator is in contact is formed with a very narrow width of 20 μm to 30 μm.
If an adhesion failure or misalignment occurs between the island portion of the vibration plate and the tip of each vibrator, accurate pressure fluctuations cannot be given to the pressure chamber, and the ejection accuracy of ink droplets decreases. A problem arises. For this reason, a high positional accuracy is required for mounting the vibrator unit, which is one of the factors that deteriorates the assemblability.

Here, it is conceivable to improve the joining easiness by increasing the width of each vibrator. However, if the width of the vibrator is simply widened, electric energy for driving the vibrator is reduced. However, there is a problem that the load on the driver circuit increases and heat is generated from the driver circuit. In addition, the power supply capacity is increased, resulting in an excessively large printer. Further, since the interval between the vibrators greatly affects the dot formation density, it is difficult to increase the resolution by increasing the width of the vibrators.

Accordingly, the present invention solves the above-mentioned problems, and a vibrator unit capable of improving the assemblability even with a vibrator having an extremely narrow width, an ink jet recording head using the vibrator unit, and manufacturing of the vibrator unit. The aim is to provide a method.

[0008]

Means for Solving the Problems The present invention has been proposed to achieve the above object, and the invention according to claim 1 is to provide a needle-like vibrator which can expand and contract by supplying a drive signal in the expansion and contraction direction. In a vibrator unit arranged in a direction perpendicular to the vibrator, a coating layer covering the front end portion of each of the vibrators is formed, and the front end area of the vibrator is enlarged. is there.

According to a second aspect of the present invention, there is provided the vibrator unit according to the first aspect, wherein the covering layer is formed continuously from a front end portion to a side end portion of each vibrator.

The invention according to claim 3 is the vibrator unit according to claim 1 or 2, wherein the coating layer is formed of a resin-based bonding agent.

According to a fourth aspect of the present invention, an external electrode connected to the internal electrode is extended to a front end face of each vibrator, and the external electrode at the front end is also covered by the coating layer. A vibrator unit according to any one of claims 1 to 3.

According to a fifth aspect of the present invention, in the vibrator unit according to any one of the first to fourth aspects, the coating layer is formed of a coating material having electrical insulation. is there.

According to a sixth aspect of the present invention, there is provided the vibrator unit according to any one of the first to fifth aspects, and a diaphragm provided with a diaphragm portion having an island portion at a portion corresponding to a pressure chamber. An ink jet recording head comprising at least each of the vibrators bonded to an island of a diaphragm via a coating layer.

According to a seventh aspect of the present invention, the vibrator is bonded to the island portion by the coating layer and then cured after the covering layer is brought into contact with the island portion of the diaphragm. An inkjet recording head according to any one of the preceding claims.

[0015] The invention described in claim 8 is a vibrator forming step of arranging a plurality of vibrators in a row by cutting a laminate formed by alternately laminating piezoelectric bodies and internal electrodes into needles,
A covering layer forming step of forming a covering layer on the leading end portions of the respective vibrators by covering the leading end portions with a coating agent.

According to a ninth aspect of the present invention, in the coating layer forming step, the tip portions of the respective vibrators are brought into contact with a coating material thinly extended on a base, so that the tip portions are coated with the coating material. The method of manufacturing a vibrator unit according to claim 8, wherein the vibrator unit is covered.

According to a tenth aspect of the present invention, there is provided the method for manufacturing a vibrator unit according to the eighth or ninth aspect, wherein a resin-based bonding agent is used as the coating agent.

The invention according to claim 11 is the method for manufacturing a vibrator unit according to any one of claims 8 to 10, wherein the coating agent has electrical insulation.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. Here, FIG. 1 is an enlarged cross-sectional view showing a main part of an ink jet recording head (hereinafter, referred to as a recording head) of the present embodiment. FIG. 2 is an enlarged view showing a joint between the diaphragm and the piezoelectric vibrator. In the description of the recording head, for convenience,
The upper side in FIG. 1 is referred to as a distal side (front side), and the lower side in FIG. 1 is referred to as a proximal side (rear side).

The illustrated recording head 1 is schematically constituted by a case 2, a flow path unit 3, a vibrator unit 4, and the like. The case 2 is a synthetic resin block-shaped member provided with an accommodation space 5 whose both front and rear ends are open. The flow path unit 3 is joined to the end of the case 2. The vibrator unit 4 is accommodated in a state where the comb-shaped tip of the vibrator group 21 faces the opening on the tip side, and the vibrator unit 4 is fixed in the case 2. Further, an ink supply pipe 6 communicating with the ink cartridge at the base end side is provided on the side of the storage space 5.

The flow channel unit 3 includes a flow channel forming plate 7, a nozzle plate 8, and a vibration plate 9. The nozzle plate 8 is a thin plate-like member having a large number (for example, 96) of nozzle openings 10 arranged in rows at a pitch corresponding to the dot formation density, and is made of, for example, a stainless steel plate.

The flow path forming plate 7 laminated on the nozzle plate 8 has a common ink chamber 11 into which the ink supplied through the ink supply pipe 6 flows, and an ink pressure necessary for discharging the ink from the nozzle openings 10. Are formed, and an ink supply port 13 for communicating the common ink chamber 11 and the pressure chamber 12 are formed. In the present embodiment, these components are formed by etching a silicon wafer.

In the present embodiment, the diaphragm 9 is made of a polymer film such as PPS (polyphenylene sulfide).
4 is a double structure laminated on a support plate 15 made of a stainless steel plate. Then, the support plate 15 at the portion corresponding to the common ink chamber 11 and the support plate 15 at the portion corresponding to the pressure chamber 12 are removed by etching or the like.
Is formed, and a diaphragm portion 17 is formed in a portion corresponding to the pressure chamber 12. The diaphragm part 17 is supported by the support plate 15.
Is formed in an annular shape, and an island portion 16 is provided at a central portion thereof. The island portion 16 is a portion where the driving vibrators 29 of the vibrator unit 4 are joined from the back side. A large number of the island portions 16 are provided at a pitch corresponding to the dot formation density in the same manner as the nozzle openings 10, the width corresponding to the nozzle arrangement direction is narrow, and the piezoelectric material laminating direction of each vibrator 29 (described later). Are formed in a block shape having a longer length corresponding to.

Then, the nozzle plate 8 is connected to the flow path forming plate 7.
The vibration plate 9 is arranged on the back side of the flow path forming plate 7 and the flow path forming plate 7, the nozzle plate 8 and the vibration plate 9 are integrated by bonding or the like. The road unit 3 is manufactured.

The vibrator unit 4 includes a vibrator group 21
And a fixing plate 22. As shown in FIG. 2, the vibrator group 21 is arranged in a comb-tooth shape, and dummy vibrators 28, 28 located at both ends in the arrangement direction of the piezoelectric vibrators, and these dummy vibrators 28 ,
And a number of driving vibrators 29 arranged between them. Here, the driving vibrators 29 are piezoelectric vibrators involved in the ejection of ink droplets.
It is cut into an extremely thin needle shape of about 00 μm. The drive vibrators 29 extend and contract in the longitudinal direction of the vibrator as described later, and are arranged in a row in a direction perpendicular to the direction of expansion and contraction. The dummy vibrators 28, 28 are piezoelectric vibrators that are not involved in the ejection of ink droplets, and are formed for positioning the vibrator unit 4 in the case 2.

Next, the driving oscillators 29 will be described in detail. As shown in FIG. 3, the driving vibrators 29.
This is a so-called longitudinal vibration mode piezoelectric vibrator formed by alternately stacking piezoelectric bodies and internal electrodes. Specifically, it is configured by alternately stacking the common internal electrodes 32 and the individual internal electrodes 33 with the piezoelectric body 31 interposed therebetween. Here, the common internal electrode 32 is an electrode that is set to the same potential level for all the driving vibrators 29. The individual internal electrode 33 is an electrode for which a potential level is set for each of the driving vibrators 29..., And the potential level changes according to the supplied driving signal. A portion of the driving vibrator 29 from the tip to about half or two thirds in the vibrator longitudinal direction (direction orthogonal to the laminating direction) is a free end 2.
3a, and the portion from the base end of the free end 23a to the base end of the vibrator is set as the base end 23b.

At the free end 23a, an active region L in which the common internal electrode 32 and the individual internal electrode 33 overlap is formed. When a potential difference is applied to these internal electrodes 32 and 33, the piezoelectric body 31 in the active region L is deformed and the free end 23
a expands and contracts in the longitudinal direction of the vibrator. The common internal electrode 32 is connected to the common external electrode 37 at the base end face of the driving vibrator 29.
, And the individual internal electrode 33 is electrically connected to the individual external electrode 36 at the distal end surface 29a of the driving vibrator 29. The distal end of the common internal electrode 32 is located slightly before the distal end surface 29a of the vibrator, and the proximal end of the individual internal electrode 33 is located at the boundary between the free end 23a and the proximal end 23b.

The individual external electrodes 36 extend in series from the wiring connection surface (upper surface in FIG. 3), which is one side surface in the laminating direction, of the driving oscillators 29 so as to cover the front end surface 29a of the driving oscillators 29. The individual electrodes 33 are electrically connected to the wiring patterns of the flexible cable 24, which is a kind of wiring member. Also, the common external electrode 3
7 includes a series of a base end surface of the driving vibrators 29, the above-described wiring connection surface, and a fixed plate mounting surface (a lower surface in FIG. 3) which is another side surface in the stacking direction of the driving vibrators 29. These electrodes form a conductive pattern between the wiring pattern of the flexible cable 24 and the common internal electrode 32.

Each of the driving vibrators 29 is covered with a coating layer 50 for enlarging the front end area of the vibrator. In the present embodiment, the dummy vibrators 28, 2
The coating layer 50 is not formed at the tip end of the dummy vibrator 8, but if the positioning accuracy is not hindered, the dummy vibrators 28, 28
May be coated with the coating layer 50.

As shown in FIG. 4, the coating layer 50 is formed not only on the front end surface 29a of each of the driving vibrators 29, but also on the periphery thereof. That is, the coating layer 50 is, for example,
Like the explosive portion of a matchstick, the tip surface 29a of the vibrator
To the side end portion 29b.
Each of the driving vibrators 29... When the coating layer 50 is formed in a series from the front end surface portion 29a to the side end portion 29b as described above, the coating layer 50 is hardly peeled off, and the bonding reliability can be improved.

Further, the coating layer 50 is formed on the individual external electrode 3.
6 is also covered. For this reason, the coating layer 50
Also function as a protective layer for protecting the individual external electrodes 36 from impact. That is, as described above, the individual external electrode 36 is formed in an L-shape from the wiring connection surface of the driving vibrator 29 to the distal end surface portion 29a. When the corner portions of the individual external electrodes 36 are exposed, there is a possibility that the individual external electrodes 36 may be peeled off due to friction with the case 2 or the like.
However, in the present embodiment, since the end portions of the individual external electrodes 36 are covered by the covering layer 50, the corner portions are also covered by the covering layer 50. Therefore, even when the vibrator unit 4 is erroneously bumped against the case 2 or the like at the time of accommodating the vibrator unit 4 in the case 2, since the covering layer 50 exists, the individual external electrodes 36 Protected. As a result, disconnection of the individual external electrode 36 due to hitting against another member such as the case 2 can be prevented,
The assemblability can be improved.

The material constituting the coating layer 50 is as follows.
For example, an epoxy resin-based or acrylic resin-based resin-based bonding agent is preferably used. More preferably, an epoxy resin adhesive or an acrylic resin adhesive is used. By configuring the coating layer 50 with a resin-based bonding agent in this manner,
The coating layer 50 can be easily formed. Further, by forming the coating layer 50 with a resin-based adhesive, the driving vibrator 29 can be bonded to the island portion 16 by the coating layer 50.

Further, the coating layer 50 is preferably made of a material having electrical insulation. The electrical insulation is required because the individual external electrodes 36, the individual internal electrodes 33, and the common internal electrodes 32
Is provided. That is, when the coating layer 50 is made of a conductive material, depending on how the coating layer 50 is provided,
There is a possibility that the common internal electrode 32 and the individual internal electrode 33 or the common internal electrode 32 and the individual external electrode 36 may be short-circuited. However, if the covering layer 50 is made of an electrically insulating material, a short-circuit between the electrodes may occur. It can be reliably prevented.

The coating layer 50 of the present embodiment is made of an epoxy resin adhesive which is a kind of resin-based bonding agent having electrical insulation.

The base portion 23b functions as a non-operating portion which does not expand and contract even when the piezoelectric body 31 in the active region L is operated. A flexible cable 24 is arranged on the wiring connection surface side of the base end 23b, and the individual external electrodes 36 and the common external electrode 37 are electrically connected to the flexible cable 24 on the base end 23b. The driving pulse is applied to each electrode 3 through the flexible cable 24.
2, 33, 36, 37. In addition, the base end 23
The fixed plate 22 is joined to the fixed plate joining surface b.
In short, the driving vibrators 29 are fixed to the fixed plate 22 in a state like a so-called cantilever.

The vibrator unit 4 having such a configuration is housed in the case 2 to which the flow path unit 3 is attached.

In this case, the vibrator unit 4 is inserted from the rear end opening of the accommodation space 5 toward the flow path unit 3 with the covering layer 50 at the top. Then, the coating layer 50
Of the driving vibrators 29...
The fixing plate 22 of the vibrator unit 4 is adhered to the inner wall of the case 2 while being positioned in a state where the vibrator unit 4 is in contact with the vibrator unit 6. Here, in the present embodiment, the coating layer 50 is made of an epoxy-based adhesive, and the coating layer 50 is brought into contact with the island portion 16 and positioned before the epoxy-based adhesive is completely cured. Then, the coating layer 50 is cured, and the driving vibrator 29 and the island portion 16 are bonded by the coating layer 50. With this configuration, the manufacturing process can be simplified, and the drive vibrator 29 and the island 16 can be securely bonded.

Further, the driving vibrator 2 is formed by the coating layer 50.
Since the front end area of each of the driving vibrators 9 is enlarged when the vibrator unit 4 is mounted in the case 2 as shown in FIG. 29 can be securely joined to the island portion 16 of the diaphragm 9. That is, since the tip area of the driving vibrator 29 is increased by the covering layer 50, the allowable range (margin) of the mounting position error is increased, and the ease of mounting is improved.

When a driving signal is supplied to the driving vibrators 29, the driving vibrators 29 expand and contract in the longitudinal direction of the vibrator and deform the elastic film 14 constituting the diaphragm portion 17 in the front-rear direction. The pressure chamber 12 expands or contracts in accordance with the movement of the diaphragm portion 17 in the front-rear direction, and changes the volume. The ink pressure in the pressure chamber 12 changes according to the change in the volume of the pressure chamber 12, and ink droplets can be ejected from the nozzle openings 10. In this case,
The tip of the driving vibrator 29...
Therefore, the expansion and contraction of the driving vibrator 29 can be reliably transmitted to the diaphragm portion 17 of the diaphragm 9. As a result, accurate pressure fluctuation can be given to the pressure chamber 12, and the ejection accuracy of the ink droplet can be increased.

Next, a method of manufacturing the vibrator unit will be described.

In manufacturing the vibrator unit, first, a plate-shaped laminated body is prepared (laminated body forming step). In this step, first, the common internal electrode 32 and the individual internal electrode 33 are connected to the piezoelectric body 31 at the front end portion serving as the free end 23a.
The common internal electrode 32 and the individual internal electrode 33 are overlapped with each other so that only the common internal electrode 32 is overlapped with the piezoelectric body 31 interposed therebetween at the base end portion serving as the base end portion 23b. Are alternately laminated with the interposed therebetween to form a plate-like laminate.

After the plate-shaped laminate is formed, the top end of the laminate and the base end 23 from the front end of the wiring connection surface are connected to each other.
b, the individual external electrodes 36 are formed in a series in the range up to and above the base plate, and the common external electrode is formed in the range from the base end of the laminate to the base end 23b of the wiring connection surface and the fixed plate mounting surface. 37 are formed in series to form a laminate with external electrodes.

Next, the laminate is fired, for example, by introducing the laminate into a firing furnace (firing step).

Thereafter, the plate-shaped laminated body is cut to produce a plurality of vibrators (vibrator forming step). In this step, first, as shown in FIG.
The fixing plate 22 is joined to the base end portion of the base member by bonding or the like. After the fixing plate 22 is joined, the laminated body 41 is divided into comb-like shapes using a wire saw, a dicing saw, or the like, and the elongated needle-like piezoelectric vibrators 29,.
Cut into 28.

When the laminated body 41 is split, the coating layer 5 is then applied to the tip of each of the driving vibrators 29 of the vibrator group 21.
0 (coating layer forming step). As described above, a resin adhesive such as an epoxy resin adhesive or an acrylic resin adhesive having electrical insulation properties is used as the coating agent.

Here, when a low-viscosity resin-based adhesive which easily causes a capillary phenomenon is used, for example, a coating layer is applied to the tip of each of the driving vibrators 29... Using the procedure shown in FIG. Form 50. That is, in this coating layer forming step, first, the coating material 52 made of a resin-based adhesive is thinly spread on the base 51, and each of the driving vibrators 29 of the vibrator unit 4 is applied to the thinly spread coating material 52. Are brought into contact with each other to transfer the coating layer 50 to the distal ends of the driving vibrators 29.

As described above, in the present embodiment, in the coating layer forming step, the vibrator group 21 of the vibrator unit 4 is brought into contact with the coating material 52 which is thinly spread on the base 51, and the respective driving vibrators 29 ... Since the coating layer 50 is formed on the tip of the drive vibrator 29 by transfer, the coating can be easily and uniformly formed on the tip of each of the driving vibrators 29. In addition, even if the adhesive has a low viscosity, the coating layer 50 is surely formed on the tip of the vibrator.
Can be provided. In addition, since the tip of the driving oscillators 29 is brought into contact after the coating material 52 is spread on the base 51, it is possible to prevent the coating material 52 from entering between the driving oscillators 29 by the capillary phenomenon. You can also. Further, since a resin-based adhesive is used as the coating agent 52, the coating layer 5 is applied to the tip of each of the driving vibrators 29.
0 can be easily formed.

When a resin-based adhesive having a high viscosity that does not easily cause a capillary phenomenon is used, the coating layer 50 can be formed on the tip of each of the driving vibrators 29 by a dipping method.

Incidentally, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the description in the claims.

For example, the coating layer 50 is not limited to the resin-based adhesive, since the coating layer 50 may be any material as long as the area at the tip of the vibrator is enlarged. For example, a resin material or a paint may be used as the coating agent 52.

In the above embodiment, the individual internal electrodes 33 and the individual external electrodes 36 are electrically connected to each other at the distal end surface 29a of the driving vibrator 29, and the common internal electrode 32 and the common external electrode 37 are connected to the driving vibration. Although the transducer unit 4 electrically connected at the base end face of the transducer 29 is illustrated, the common internal electrode 32 and the common external electrode 37 are electrically connected at the tip face 29a of the driving transducer 29, and The present invention can also be applied to a vibrator unit in which the internal electrodes 33 and the individual external electrodes 36 are electrically connected at the base end surface of the driving vibrator 29.

In the above embodiment, the driving oscillator 2
Although the configuration in which 9 and the island portion 16 are joined by the resin-based bonding agent coating layer 50 has been exemplified, the present invention is not limited to this configuration. For example, after the coating layer 50 is cured, the cured coating layer 50 and the island 16 may be joined. In this case, it is preferable to apply an adhesive to the cured coating layer 50 and adhere it to the island portion 16 because of good workability. Further, it is more preferable that the tip of the driving vibrator 29 and the island portion 16 are adhered to each other by an adhesive constituting the coating layer 50. By doing so, the affinity between the adhesives can be increased, and the drive oscillator 29 and the island 16 can be securely bonded. The cured coating layer 50 and the island portion 16 may be joined by brazing (for example, soldering).

When the coating material 52 is in a semi-cured state,
Alternatively, the distal end face of the coating layer 50 may be positively crushed by pressing against the first or the like. By doing so, the distal end surface of the coating layer 50 is formed as a smooth flat surface, so that the reliability of bonding can be improved.

The vibrators constituting the vibrator group are not limited to the piezoelectric vibrators, but may be any vibrators that can expand and contract by supplying a drive signal. For example, a magnetostrictive element may be used as a vibrator.

The method of forming the coating layer 50 in the above-described coating layer forming step is not limited to the method of the present embodiment. For example, a liquid ejecting head having the same configuration as the above-described ink jet recording head 1, that is, a liquid flow path communicating from the common liquid chamber to the nozzle opening via the pressure chamber, and a pressure generating element for changing the liquid pressure in the pressure chamber A liquid ejecting head that ejects liquid from nozzle openings by changing the liquid pressure in the pressure chamber may be used, and a coating material such as a paint, an adhesive, or a resin may be ejected from the liquid ejecting head.

[0056]

As described above, according to the present invention, the following effects can be obtained. That is, since a coating layer covering the front end portion is formed on the front end portion of each vibrator and the front end area of the vibrator is enlarged, when the vibrator unit is attached, even if the piezoelectric vibrator is displaced, Each vibrator and the island portion can be securely joined via the coating layer. Therefore, it is possible to prevent poor connection between each transducer and the island.

When the covering layer is formed in a series from the front end face to the side face of each vibrator, the covering layer can be hardly peeled off.

When the coating layer is formed of a resin-based bonding agent, the coating layer can be easily formed. Further, the vibrator and the island can be joined by the covering layer.

In the case where the external electrodes that are electrically connected to the internal electrodes are extended to the front end face of each vibrator and the external electrodes at the front end portions are also covered by the covering layer, the external electrodes are mechanically covered by the covering layer. Can be protected from physical shock.

In the case where the coating layer is formed of a coating material having an electrical insulating property, a short circuit between the electrodes can be reliably prevented.

When each vibrator is joined to the island of the diaphragm via the coating layer, each vibrator can be securely joined to the island of the diaphragm. Therefore, it is possible to prevent poor connection between the vibrator and the island. Further, since the expansion and contraction of the vibrator can be reliably transmitted to the vibrating plate, the ejection characteristics of ink droplets can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ink jet recording head.

FIG. 2 is an enlarged view showing a joint between a vibration plate and a piezoelectric vibrator.

FIG. 3 is a cross-sectional view illustrating a laminated structure of a transducer unit.

FIG. 4 is a perspective view showing a distal end portion of a driving vibrator.

FIG. 5 is a schematic diagram illustrating a joining state between a tip portion of each vibrator and an island portion of a diaphragm.

FIGS. 6A and 6B are explanatory views showing a method of manufacturing the vibrator unit of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 2 Case 3 Flow path unit 4 Vibrator unit 5 Storage space 6 Ink supply pipe 7 Flow path forming plate 8 Nozzle plate 9 Vibration plate 10 Nozzle opening 11 Common ink chamber 12 Pressure chamber 13 Ink supply port 14 Elastic film REFERENCE SIGNS LIST 15 support plate 16 island portion 17 diaphragm portion 18 compliance portion 21 vibrator group 22 fixing plate 23a free end 23b base end 24 flexible cable 28 dummy vibrator 29 drive vibrator 29a front end surface 29b side end 31 piezoelectric body 32 common Internal electrode 33 Individual internal electrode 36 Individual external electrode 37 Common external electrode 41 Stack 50 Coating layer 51 Base 52 Coating agent

Claims (11)

[Claims] 1. A vibrator unit in which needle-shaped vibrators that can be expanded and contracted by supply of a drive signal are arranged in a direction perpendicular to the direction of expansion and contraction. A vibrator unit, wherein the vibrator unit is formed and the tip area of the vibrator is enlarged. 2. The vibrator unit according to claim 1, wherein the covering layer is formed continuously from a front end face to a side end of each vibrator. 3. The vibrator unit according to claim 1, wherein the coating layer is formed of a resin-based bonding agent. 4. An external electrode, which is electrically connected to the internal electrode, is extended to a distal end face of each vibrator, and the external electrode at the distal end is also covered by the coating layer. The vibrator unit according to any one of the above. 5. The vibrator unit according to claim 1, wherein the coating layer is formed of a coating material having electrical insulation. 6. The vibrator unit according to claim 1, further comprising: a vibrating plate provided with a diaphragm portion having an island portion at a portion corresponding to a pressure chamber. Is bonded to the island portion of the diaphragm via a coating layer. 7. The ink jet recording head according to claim 6, wherein the coating layer is cured after being brought into contact with the island portion of the diaphragm, and the vibrator is bonded to the island portion by the coating layer. 8. A vibrator forming step of arranging a plurality of vibrators in rows by cutting a laminated body formed by alternately laminating piezoelectric bodies and internal electrodes into needles, and covering a tip portion of each vibrator. And a covering layer forming step of forming a covering layer on the front end portion by covering with an agent. 9. The coating layer forming step is characterized in that the tip portions of the respective vibrators are brought into contact with a coating material thinly extended on a base to cover the tip portions with the coating material. Item 10. A method for manufacturing a vibrator unit according to item 8. 10. The method according to claim 8, wherein a resin-based bonding agent is used as the coating agent. 11. The method according to claim 8, wherein the coating has electrical insulation.