JP2000211129A - Ink jet recording head - Google Patents

Abstract

(57) Abstract: An ink jet recording head capable of reliably preventing contact between a flexible circuit board and a piezoelectric vibrator is provided. A pressure chamber forming substrate provided with a space for forming a pressure generating chamber, and a nozzle opening communicating with the pressure generating chamber are formed on one side of the pressure chamber forming substrate. A nozzle plate 17 for closing the opening of the space,
A vibrating plate 11 on the other surface side of the pressure chamber forming substrate 10 for closing the opening of the space, and a piezoelectric vibrator 6 formed on the outer surface of the vibrating plate 11 to generate pressure in the pressure generating chamber 2
And a flexible circuit board 22 stretched so as to cover the surface of the piezoelectric vibrator 6, wherein at least a gap between the piezoelectric vibrator 6 and the flexible circuit board 22 is liquid or liquid. The presence of the gel insulating material 7 prevented contact between the flexible circuit board 22 and the piezoelectric vibrator 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording head to which a piezoelectric vibrator of a flexural vibration mode is mounted.

[0002]

2. Description of the Related Art In general, an ink jet recording head (hereinafter referred to as a "recording head") provided with a piezoelectric vibrator in a flexural vibration mode has an actuator in which a plurality of pressure generating chambers 2 are formed as shown in FIG. Unit 1
A flow path unit 5 in which a nozzle opening 3 and an ink storage chamber 4 are formed and attached to the lower surface of the actuator unit 1; and a piezoelectric vibrator 6 attached to the upper surface of the actuator unit 1. A pressure is generated in the pressure generating chamber 2 by the vibration of the piezoelectric vibrator 6, and an ink droplet is ejected from the nozzle opening 3.

The actuator unit 1 includes a pressure chamber forming substrate 10 in which a space for forming the pressure generating chamber 2 is formed.
A vibrating plate 11 positioned on the upper surface of the pressure chamber forming substrate 10 and closing the upper opening of the space;
And a lid member 14 located on the lower surface of the cover.
The lid member 14 is formed with a first ink flow path 12 that connects the ink storage chamber 4 and the pressure generation chamber 2 and a second ink flow path 13 that connects the pressure generation chamber 2 and the nozzle opening 3. .

The flow channel unit 5 includes a storage chamber forming substrate 16 in which a space for forming the ink storage chamber 4 is formed, and a nozzle plate formed with a nozzle opening 3 and located on the lower surface of the storage chamber forming substrate 16. 17 and the storage chamber forming substrate 1
6 and a supply port forming plate 18 located on the upper surface of the nozzle 6. The storage chamber forming substrate 16 is formed with a nozzle communication port 9 communicating with the nozzle opening 3. The supply port forming plate 18 is provided with an ink supply port 15 for supplying ink from the ink storage chamber 4 to the pressure generation chamber 2 via the first ink flow path 12. A communication port 8 for communicating the second ink flow path 13 with the nozzle communication port 9 and the nozzle opening 3 is formed.

The piezoelectric vibrator 6 is formed in a flat plate shape at a portion corresponding to the pressure generating chamber 2 on the upper surface of the vibration plate 11. A lower electrode 1 is provided on the lower surface of the piezoelectric vibrator 2.
The upper electrode 20 is formed on the upper surface so as to cover the piezoelectric vibrator 6. Further, terminals 21 that are electrically connected to the upper electrode 20 of each piezoelectric vibrator 6 are formed at both ends of the upper surface of the actuator unit 1. The upper surface of the terminal 21 is formed higher than the upper surface of the piezoelectric vibrator 6. A flexible circuit board 22 is stretched on the upper surface of the terminal 21 so that a drive signal is applied to the piezoelectric vibrator 6 via the terminal 21 and the upper electrode 20. Although only two pressure generating chambers 2, two piezoelectric vibrators 6, and two terminals 21 are shown in the figure,
Many rows are arranged in the vertical direction on the paper.

In the recording head, when a drive signal is applied to the piezoelectric vibrator 6, the piezoelectric vibrator 6 contracts in the horizontal direction as shown in FIG. At this time, the lower surface side of the piezoelectric vibrator 6 fixed to the vibration plate 11 does not shrink, and only the upper surface side contracts, so that the piezoelectric vibrator 6 and the vibration plate 11 bend downward like bimetal and generate pressure. Compress chamber 2. When the pressure in the pressure generating chamber 2 rises, the ink in the pressure generating chamber 2 is discharged from the nozzle opening 3 into the ink droplet 23.
And printing is performed on recording paper or the like. Then
When the piezoelectric vibrator 6 is discharged and returns to the original state, the pressure in the pressure generating chamber 2 is reduced and the ink supply chamber 1 is moved from the ink storage chamber 4 to the ink supply port 1.
New ink is supplied to the pressure generating chamber 2 through 5.

[0007]

However, in the above-described recording head, the flexible circuit board 22 is provided on the upper surface of the actuator unit 1 so as to cover a large number of piezoelectric vibrators 6.
Is stretched. And the flexible circuit board 2
2 also has an action of preventing foreign matter from adhering to the surface of the piezoelectric vibrator 6. That is, on the surface of the piezoelectric vibrator 6,
When foreign matter, particularly a compound containing halogen such as Cl or Br, adheres, a phenomenon (so-called migration) in which a metal shifts from the positive side to the negative side of the voltage due to the influence of moisture in the surrounding atmosphere and the influence of voltage application. May occur. Such foreign matter containing halogen is also suspended in a large amount in the general atmosphere, and prevents the foreign matter from directly adhering to the piezoelectric vibrator 6. To make this work effectively, the flexible circuit board 22 needs to be as close to the piezoelectric vibrator 6 as possible.

However, when the flexible circuit board 22 is loosely stretched, the flexible circuit board 22
May come into contact with the piezoelectric vibrator 6. In addition, since the recording head during printing reciprocates violently in the width direction of the recording paper, the vibration at this time causes the flexible circuit board 22 to flutter and the contact with the piezoelectric vibrator 6 is likely to occur. In this way, when the contact between the flexible circuit board 22 and the piezoelectric vibrator 6 occurs, smooth vibration of the piezoelectric vibrator 6 is prevented,
The characteristics of the piezoelectric vibrator 6 may be changed, which may have a bad influence on print quality. In the worst case, the piezoelectric vibrator 6 itself may be damaged.

On the other hand, the terminals 21 are mostly formed of silver, copper, solder chips, etc., and the aspect ratio cannot be so high for the sake of production.
There is a limit in increasing the distance of the gap between the piezoelectric vibrator 2 and the piezoelectric vibrator 6. Furthermore, in recent years, there has been a tendency to reduce the thickness of the piezoelectric vibrator 6 itself in order to give effective vibration to the vibration plate 11 at a low voltage due to high functionality and low cost of the ink jet recording apparatus. In this case, when the contact between the flexible circuit board 22 and the piezoelectric vibrator 6 occurs, the characteristic fluctuation of the piezoelectric vibrator 6 increases, and the piezoelectric vibrator 6 itself is delicate and easily damaged. Under such circumstances, there has been a strong demand for the development of an ink jet recording head that reliably prevents the flexible circuit board 22 from contacting the piezoelectric vibrator 6 and prevents foreign substances from adhering to the piezoelectric vibrator. .

The present invention has been made in view of such circumstances, and can reliably prevent contact between a flexible circuit board and a piezoelectric vibrator and prevent foreign substances from adhering to the piezoelectric vibrator. It is intended to provide an ink jet recording head.

[0011]

To achieve the above object, an ink jet recording head according to the present invention comprises a pressure chamber forming substrate provided with a space for forming a pressure chamber, and a nozzle opening communicating with the pressure chamber. A nozzle member that is bored and is on one side of the pressure chamber forming substrate and closes the opening of the space;
A vibrating plate on the other surface side of the pressure chamber forming substrate to close the opening of the space, a piezoelectric vibrator formed on an outer surface of the vibrating plate to generate pressure in the pressure chamber, and a surface of the piezoelectric vibrator An ink jet recording head comprising a covering member stretched so as to cover, wherein at least a liquid or gel-like insulating substance is present in a gap between the piezoelectric vibrator and the covering member. I do.

That is, in the ink jet recording head of the present invention, a liquid or gel insulating material is present at least in a gap between the piezoelectric vibrator and the covering member. For this reason, even if the covering member is loosely stretched, the covering member hardly comes into contact with the piezoelectric vibrator due to the presence of the insulating material. Further, even when the covering member fluctuates a little, the piezoelectric vibrator is guarded by the insulating material and hardly comes into contact with the covering member.
As described above, the contact between the covering member and the piezoelectric vibrator is prevented, the characteristics of the piezoelectric vibrator are hardly changed, and the adverse effect on print quality is prevented. Further, since the insulating material is in a liquid or gel state, it does not hinder the vibration of the piezoelectric vibrator. In addition, even when an external force is applied to the covering member, the insulating substance serves as a cushion to protect the piezoelectric vibrator and prevent the piezoelectric vibrator from being damaged.

In the ink jet recording head of the present invention, when the surface of the piezoelectric vibrator is covered with an insulating material, the contact between the covering member and the piezoelectric vibrator can be reliably prevented, and the piezoelectric vibrator can be used. This has the effect of blocking moisture and foreign matter and preventing malfunction of the recording head. That is, in the piezoelectric vibrator, a phenomenon occurs in which the intermediate voltage of the drive signal gradually decreases due to the influence of the leakage current of the switching element and the piezoelectric vibrator itself. Giving a return signal has been done.

However, when the piezoelectric vibrator is exposed to high humidity, the resistance between the electrodes of the piezoelectric vibrator decreases, the intermediate voltage drops sharply, and when a signal for returning the potential is given, the print signal is Irrespective of this, a malfunction may occur in which ink droplets are ejected. Further, in the case where foreign matter containing a halogen compound adheres to the surface of the piezoelectric vibrator, the resistance value is further reduced. As described above, by covering the surface of the piezoelectric vibrator with the insulating material, the piezoelectric vibrator is reliably shielded from moisture and foreign substances, and the above-described malfunction is reliably prevented.

In the ink jet recording head according to the present invention, when the insulating substance is present in a state of a thickness of 1 μm or more and 10 mm or less, or when the thickness of the insulating substance is 1/10 or more of the thickness of the piezoelectric vibrator. When the insulating material is present in a state of 300 times or less, or the insulating material has a thickness of 10 to 30,000 times the deformation amount of the piezoelectric vibrator at the time of discharge.
When present in a state of 0 times or less, the vibration of the piezoelectric vibrator is hardly hindered, the contact between the covering member and the piezoelectric vibrator can be effectively prevented, and the piezoelectric vibrator is reliably shut off from moisture. As a result, malfunction can be prevented.

In the ink jet recording head of the present invention, when the insulating material has a Young's modulus of 1 × 10 ⁴ Pa or less, or when the insulating material is a piezoelectric vibrator when the Young's modulus ejects ink, When the pressure is 1% or less of the generated pressure, the insulating substance does not flow out of the gap between the piezoelectric vibrator and the covering member even when vibration or the like during printing is applied. In addition, the cushioning effect of the insulating material is remarkable, and the piezoelectric vibrator is reliably prevented from being damaged. Further, the vibration of the piezoelectric vibrator is hardly hindered.

In the ink jet recording head of the present invention, when a hole for injecting an insulating material is formed in the covering member, the operation of injecting the insulating material is easy, and the manufacturing is easy.

In the ink jet recording head of the present invention, when a plurality of the above holes are formed, air escapes from another hole when an insulating material is injected from one hole, so that bubbles are generated inside. It is unlikely to remain, and the insulating substance can be more reliably filled.

In the ink jet recording head according to the present invention, when the hole is provided between a plurality of piezoelectric vibrators, the insulating material is provided from a place where a gap between the piezoelectric vibrator and the covering member is wide. Since it spreads to a narrow place by capillary action, the insulating material can be more reliably filled.

In the ink jet recording head according to the present invention, when the insulating material is filled in the gap between the piezoelectric vibrator and the covering member, the covering member flutters even when vibration is applied during printing. Thus, the contact with the piezoelectric vibrator can be effectively prevented.

In the ink jet recording head of the present invention, when the covering member is a flexible circuit board,
This makes it possible to effectively prevent contact between the flexible circuit board, which is likely to flap or bend by the movement of the recording head during printing, and the piezoelectric vibrator.

[0022]

Next, embodiments of the present invention will be described in detail.

FIG. 1 is a view showing an example of an ink jet recording head of the present invention. This recording head is basically the same as that shown in FIG. 5, and the same parts are denoted by the same reference numerals. In this recording head, a liquid or gel-like insulating substance 7 is present in a gap between the piezoelectric vibrator 6 and the flexible circuit board 22. Further, a hole 24 for injecting the insulating material 7 is formed in the flexible circuit board 22.

It is desirable that a plurality of holes 24 formed in the flexible circuit board 22 are formed as shown in FIG. 2, for example.
When the insulating material 7 is injected from one of the holes 24, the other holes 2
Since air escapes from the space 4, air bubbles hardly remain in the gap between the piezoelectric vibrator 6 and the flexible circuit board 22, and the insulating material 7 can be more reliably filled.

The hole 24 is preferably provided at a position between the piezoelectric vibrators 6 in plan view. By doing so, the insulating substance 7 spreads from the wide gap to the narrow gap between the piezoelectric vibrator 6 and the flexible circuit board 22 by capillary action, so that the insulating substance 7 is more reliably filled. Can be even more effective.

The insulating substance 7 is not particularly limited as long as it is liquid or gel at room temperature, and various substances are used. For example, animal and vegetable oils such as linseed oil and beeswax, mineral oils, petroleum oils such as paraffin, asphalt, synthetic oils such as silicone oil, fluorine oil, chlorinated oil, diphenyl chloride, grease, resin materials such as silicone gel and epoxy resin. And the like. Among these, silicone oils and silicone gels which are excellent in heat resistance, chemical resistance and aging resistance are particularly suitable. In the present invention, the liquid or gel state includes a fluid state exhibiting high fluidity at a low viscosity, a slurry state having a relatively high viscosity and a low fluidity, a grease state and a jelly state exhibiting almost no fluidity. is there.

Further, among the above various insulating substances 7,
It does not flow out of the gap between the piezoelectric vibrator 6 and the flexible circuit board 22 even when vibration is applied, and the cushion effect can be reliably prevented from damaging the piezoelectric vibrator 6, so that the Young's modulus is 1 × 10 ⁴ Pa or less. Is preferred. The upper limit of the Young's modulus is more preferably 200 Pa, and more preferably 50 Pa or less. Here, the relationship between the Young's modulus of the insulating material 7 and the hardness of the insulating material 7 is approximately calculated by the following equation (1). However, the following equation (1) is an approximate equation, and varies depending on the material, temperature, curing conditions, measurement conditions, and the like.

Young's modulus [Pa] ≒ 11 exp (0.155 × Shore A hardness [°]) (1) When the above Young's modulus is large, for example, when an insulating material 7 of 1 × 10 ⁵ Pa or more is used, The vibration of the piezoelectric vibrator 6 is hindered.

When ejecting ink, the piezoelectric vibrator 6 generates a pressure ΔP shown in the following equation (2).
By setting the Young's modulus of the insulating material to 1% or less, preferably 0.005% or less with respect to this pressure, the piezoelectric vibrator 6
Is hardly inhibited.

ΔP = ΔV / C (2) ΔV: Volume eliminated by the piezoelectric vibrator C: Rigidity compliance of the laminated structure of the piezoelectric vibrator and the diaphragm The insulating material 7 is as shown in FIG. , Piezoelectric vibrator 6
It is preferred to be present so as to cover the surface. By doing so, the contact between the flexible circuit board 22 and the piezoelectric vibrator 6 can be reliably prevented, and the piezoelectric vibrator 6 can be shielded from moisture and foreign substances, thereby preventing malfunction of the recording head.

That is, since the piezoelectric vibrator 6 is a kind of capacitor, as shown in FIG. 3A, the drive signal S1 and the drive signal S2 are separated by the influence of the leakage current in the piezoelectric vibrator and the circuit. Between them, a phenomenon occurs in which the intermediate voltage Vm gradually drops. For this reason, in order to restore the dropped intermediate voltage, as shown in FIG. 3B, a signal for forcibly returning the potential at a certain timing (t in the drawing) is provided. However, when the piezoelectric vibrator 6 is exposed to high humidity, dew condensation or the like occurs, the resistance between the upper electrode 20 and the lower electrode 19 of the piezoelectric vibrator 6 decreases, and the drop of the intermediate voltage Vm increases.

Further, foreign matter near the electrodes of the piezoelectric vibrator 6
In particular, when a compound containing a halogen such as Cl or Br adheres, migration occurs and the voltage drops more remarkably. In this embodiment, the electrode material on the positive voltage side is Au, and the electrode material on the negative voltage side is Pt.
Au is a relatively migration hardly occurs materials compared to Ag, etc. However, Cl ^- or Br ^- by the interaction of the halide ions and water such as sometimes migration occurs.

When a signal for returning the voltage is applied in such a state, as shown in FIG. 3 (c), the voltage rise when the potential returns is increased, and the voltage is increased independently of the driving signals S1 and S2 at the time of printing. The piezoelectric vibrator 6 vibrates greatly, causing an erroneous operation in which ink droplets are ejected.

As described above, by covering the surface of the piezoelectric vibrator 6 with the insulating material 7, the piezoelectric vibrator 6 is reliably shielded from moisture and foreign substances, and the above-described malfunction is reliably prevented. It is.

The insulating material 7 has a thickness of 1 μm to 10 mm in order to effectively prevent contact between the flexible circuit board 22 and the piezoelectric vibrator 6 and to reliably shield the piezoelectric vibrator 6 from moisture and foreign matter. It is more preferable to exist in the following state. 1 mm is more preferable as the upper limit value of the thickness, and 500 μm is more preferable. 10 μm is more preferable as the lower limit of the thickness.
And 100 μm is more preferable.

When the thickness of the insulating material 7 is very thin and comes into contact with the flexible circuit board 22,
For example, when the thickness is about 0.1 μm, the rigidity of the flexible circuit board 22 affects the vibration of the piezoelectric vibrator 6. For example, the thickness of the piezoelectric vibrator 6 is 10 μm.
m, when the piezoelectric vibrator 6 having a deformation amount of about 0.1 μm when ejecting ink is used, the thickness of the insulating material 7 is at least one-tenth or more of the thickness of the piezoelectric vibrator 6. If the amount is 10 times or more, the vibration of the piezoelectric vibrator 6 is hardly hindered. On the other hand, when the thickness of the insulating material is large, for example, the thickness is 20 mm or more, the thickness exceeds 300 times the thickness of the piezoelectric vibrator 6, or the deformation amount is 3000.
When the thickness exceeds 00 times, there is a problem that the movement of the piezoelectric vibrator 6 becomes slow due to the influence of the weight.

As described above, in the recording head, the presence of the insulating material 7 reliably prevents the contact between the flexible circuit board 22 and the piezoelectric vibrator 6 and does not hinder the vibration of the piezoelectric vibrator 6. There is almost no change in the characteristics of the child 6, and the adverse effect on the print quality is prevented.

FIG. 4 shows a recording head according to a second embodiment of the present invention. In this device, the insulating material 7 is filled in the gap between the piezoelectric vibrator 6 and the flexible circuit board 22. In this case, the fluttering of the flexible circuit board 22 is suppressed even when vibration or the like during printing is applied, and contact with the piezoelectric vibrator 6 is effectively prevented. Other than that, it is the same as that shown in FIGS. 1 and 2, and has the same effect.

In each of the above embodiments, the present invention
Although an example in which the present invention is applied to a recording head in which a flexible circuit board 22 is stretched over the piezoelectric vibrator 6 has been described, the present invention is not limited to this. Instead of the flexible circuit board 22, a semiconductor integrated circuit board or a semiconductor The present invention can be applied to a structure in which a fixed substrate on which an integrated circuit is fixed, a structure in which a package or the like in which a semiconductor integrated circuit is housed is stretched, or a structure in which another plastic film, a metal thin plate, or the like is stretched. In each of the above embodiments, the insulating material 7 covers the piezoelectric vibrator 6. However, the present invention is not limited to this, and the insulating material 7 may partially exist on the surface of the piezoelectric vibrator 6. . Further, the insulating material 7 may be present not only in the gap between the piezoelectric vibrator 6 and the flexible circuit board 22 but also on the upper surface of the flexible circuit board 22. Even in these cases, the same operation and effect can be obtained.

[0040]

As described above, according to the ink jet recording head of the present invention, even when the covering member is loosely stretched, the covering member contacts the piezoelectric vibrator due to the presence of the insulating material. There are few things. Further, even when the covering member fluctuates a little, the piezoelectric vibrator is guarded by the insulating material and hardly comes into contact with the covering member. As described above, the contact between the covering member and the piezoelectric vibrator is prevented, the characteristics of the piezoelectric vibrator are hardly changed, and the adverse effect on print quality is prevented. Further, since the insulating material is in a liquid or gel state, it does not hinder the vibration of the piezoelectric vibrator. In addition, even when an external force is applied to the covering member, the insulating substance serves as a cushion to protect the piezoelectric vibrator and prevent the piezoelectric vibrator from being damaged.

In the ink jet recording head of the present invention, when the surface of the piezoelectric vibrator is covered with an insulating material, contact between the covering member and the piezoelectric vibrator can be reliably prevented, and the piezoelectric vibrator can be used. This has the effect of blocking moisture and foreign matter and preventing malfunction of the recording head. That is, in the piezoelectric vibrator, a phenomenon occurs in which the intermediate voltage of the drive signal gradually decreases due to the influence of the leakage current of the switching element and the piezoelectric vibrator itself. Giving a return signal has been done.

However, when the piezoelectric vibrator is exposed to high humidity, the resistance value between the electrodes of the piezoelectric vibrator decreases and the intermediate voltage drops sharply. Irrespective of this, a malfunction may occur in which ink droplets are ejected. Further, in the case where foreign matter containing a halogen compound adheres to the surface of the piezoelectric vibrator, the resistance value is further reduced. As described above, by covering the surface of the piezoelectric vibrator with the insulating material, the piezoelectric vibrator is reliably shielded from moisture and foreign substances, and the above-described malfunction is reliably prevented.

In the ink jet recording head of the present invention, when the insulating substance is present in a state of a thickness of 1 μm or more and 10 mm or less, or when the thickness of the insulating substance is 1/10 or more of the thickness of the piezoelectric vibrator. When the insulating material is present in a state of 300 times or less, or the insulating material has a thickness of 10 to 30,000 times the deformation amount of the piezoelectric vibrator at the time of discharge.
When present in a state of 0 times or less, the vibration of the piezoelectric vibrator is hardly hindered, the contact between the covering member and the piezoelectric vibrator can be effectively prevented, and the piezoelectric vibrator is reliably shut off from moisture. As a result, malfunction can be prevented.

In the ink jet recording head of the present invention, when the insulating material has a Young's modulus of 1 × 10 ⁴ Pa or less, or when the insulating material is a piezoelectric vibrator when the Young's modulus discharges ink, When the pressure is 1% or less of the generated pressure, the insulating substance does not flow out of the gap between the piezoelectric vibrator and the covering member even when vibration or the like during printing is applied. In addition, the cushioning effect of the insulating material is remarkable, and the piezoelectric vibrator is reliably prevented from being damaged. Further, the vibration of the piezoelectric vibrator is hardly hindered.

In the ink jet recording head of the present invention, when a hole for injecting an insulating material is formed in the covering member, the operation of injecting the insulating material is easily performed, and the manufacturing is facilitated.

In the ink jet recording head of the present invention, when a plurality of the above holes are formed, air escapes from another hole when an insulating substance is injected from one hole, so that air bubbles are generated inside. It is unlikely to remain, and the insulating substance can be more reliably filled.

In the ink jet recording head according to the present invention, when the hole is provided between a plurality of piezoelectric vibrators, the insulating material is provided from a place where a gap between the piezoelectric vibrator and the covering member is wide. Since it spreads to a narrow place by capillary action, the insulating material can be more reliably filled.

In the ink jet recording head of the present invention, when the insulating material is filled in the gap between the piezoelectric vibrator and the covering member, the covering member flutters even when vibrations during printing are applied. Thus, the contact with the piezoelectric vibrator can be effectively prevented.

In the ink jet recording head of the present invention, when the covering member is a flexible circuit board,
This makes it possible to effectively prevent contact between the flexible circuit board, which is likely to flap or bend by the movement of the recording head during printing, and the piezoelectric vibrator.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an ink jet recording head of the present invention.

FIG. 2 is a plan view showing the ink jet recording head.

FIG. 3 is a diagram illustrating the operation of the ink jet recording head of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the ink jet recording head of the present invention.

FIG. 5 is a sectional view showing a conventional ink jet recording head.

FIG. 6 is a sectional view showing the operation of the ink jet recording head.

[Explanation of symbols]

 2 Pressure generating chamber 3 Nozzle opening 6 Piezoelectric vibrator 7 Insulating substance 10 Pressure chamber forming substrate 11 Vibration plate 17 Nozzle plate 22 Flexible circuit board

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shikinori Okumura 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Inventor Takahiro Katakura 3-5-5 Yamato, Suwa City, Nagano Prefecture Seiko Epson Inside the corporation

Claims (12)

[Claims] 1. A pressure chamber forming substrate provided with a space for forming a pressure chamber, and a nozzle opening communicating with the pressure chamber is drilled to close one side of the pressure chamber forming substrate to close the opening of the space. A nozzle member, a vibrating plate on the other surface side of the pressure chamber forming substrate to close the opening of the space, a piezoelectric vibrator formed on an outer surface of the vibrating plate to generate pressure in the pressure chamber, An ink jet recording head comprising a covering member stretched so as to cover the surface of the vibrator, wherein a liquid or gel insulating material is present at least in a gap between the piezoelectric vibrator and the covering member. An ink jet recording head, characterized in that: 2. The ink jet recording head according to claim 1, wherein the surface of the piezoelectric vibrator is covered with an insulating material. 3. An insulating material having a thickness of 1 μm or more and 10 mm or more.
3. The ink jet recording head according to claim 1, wherein the recording head is present in the following state. 4. The ink jet recording head according to claim 1, wherein the insulating material is present in a state where the thickness is at least 1/10 and at most 300 times the thickness of the piezoelectric vibrator. 5. The ink jet recording head according to claim 1, wherein the insulating material is present in a state where the thickness is 10 to 300,000 times the deformation amount of the piezoelectric vibrator at the time of discharge. 6. The insulating substance has a Young's modulus of 1 × 10 ⁴ Pa.
The ink jet recording head according to claim 1, wherein the ink jet recording head is: 7. The ink jet recording according to claim 1, wherein the insulating material has a Young's modulus of 1% or less of a pressure generated by the piezoelectric vibrator when the ink is ejected. head. 8. The ink jet recording head according to claim 1, wherein a hole for injecting an insulating substance is formed in the covering member. 9. An ink jet recording head according to claim 8, wherein a plurality of said holes are formed. 10. The ink jet recording head according to claim 8, wherein the hole is provided between a plurality of piezoelectric vibrators. 11. The ink jet recording head according to claim 1, wherein the insulating material is filled in a gap between the piezoelectric vibrator and the covering member. 12. The ink jet recording head according to claim 1, wherein the covering member is a flexible circuit board.