JPH09277532A - Laminated type ink jet recording head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a pressure generating chamber without reducing the emitting amt. of ink droplets. SOLUTION: A first vibration inducing plate 26 having rigidity higher than that of a vibration plate 24 is fixed to the upper surface of a region where a drive electrode 25 is formed and second vibration inducing plates 28, 28 having rigidity higher than that of the vibration 24 are fixed to the rear surface of the vibration plate 24 so as to be contiguous to the first vibration inducing plate 26 and the reaction force of the second vibration inducing plates 28, 28 is put to practical use to expand the bending quantity of the first vibration inducing plate 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated ink jet recording head for ejecting ink droplets from a nozzle opening by expanding and contracting a pressure generating chamber by a piezoelectric vibrator vibrating and bending.

[0002]

2. Description of the Related Art For example, as disclosed in Japanese Patent Laid-Open No. 6-40035, a piezoelectric vibrating plate is attached to a partial area of an elastic plate that constitutes a pressure generating chamber, and the piezoelectric vibrating plate is flexibly displaced. The ink jet recording head that generates ink droplets by changing the volume of the pressure chamber is capable of displacing a large area of the pressure generating chamber, and thus has the characteristic that ink droplets can be generated stably. There is.

In such a recording head, a pressure generating chamber, a vibration plate, and an actuator unit made by sintering a piezoelectric vibration plate are usually formed by sintering a ceramic, and a metal plate is formed corresponding to a plurality of nozzle opening rows. It is configured by being fixed to a single flow path forming unit composed of (1) through an adhesive layer. With such a configuration, at least the actuator unit can be configured by sintering work, and the number of manufacturing steps can be reduced. However, as the recording density becomes higher, the size of the piezoelectric diaphragm becomes smaller, making it extremely difficult to attach or apply the green sheet of piezoelectric material to the green sheet that will become the diaphragm, especially at the edge of the piezoelectric diaphragm. There is a problem in that the characteristics of the piezoelectric vibrator vary due to poor bonding or the like.

In order to solve such a problem, Japanese Unexamined Patent Publication No.
As seen in Japanese Patent No. 261921, a vibrating plate is made of a piezoelectric material, and driving electrodes are selectively formed on the surface of the vibrating plate only in a region facing the pressure generating chamber, and flexural vibration is induced on the surface of the driving electrode. An ink jet recording apparatus has been proposed in which a rigid member is built in. According to this, since the piezoelectric vibrating plate is configured as a single plate, it is less likely to be affected by the bonding failure as compared with the case where the piezoelectric vibrating plate is formed independently here, so that the ink ejection characteristics are made uniform over all nozzle openings. can do.

[0005]

However, when it is attempted to print at a higher density, there is a problem in that it is not possible to obtain a sufficient displacement amount for ejecting ink droplets. The present invention has been made in view of the above problems, and an object of the present invention is to provide a stacked ink jet recording head capable of stabilizing and increasing the displacement amount of a piezoelectric vibrator. Is. Another object of the present invention is to propose a method of manufacturing the above recording head.

[0006]

In order to solve such a problem, according to the present invention, a drive electrode is made of a piezoelectric material, the front surface of which is opposed to the pressure generating chamber, and the back surface of which is at least the pressure generating chamber. A diaphragm in which a common electrode is formed in a region facing each other, and a pressure generation chamber forming substrate that forms one of the pressure generation chambers with one surface sealed by the vibration plate,
While sealing the other surface of the pressure generating chamber forming substrate,
An ink supply port that supplies ink from a common ink chamber to the pressure generation chamber, an actuator unit that includes an ink supply port formation substrate that connects the pressure generation chamber and the nozzle opening, and an ink supply unit that supplies ink from the pressure generation chamber. In a laminated ink jet recording head in which a nozzle opening that receives a supply and discharges an ink droplet and a flow path unit having the common ink chamber are integrally joined, the pressure is generated on the surface of the drive electrode. A first vibration induction plate having a rigidity higher than that of the vibration plate so as to face the chamber, and a first vibration induction plate having a rigidity higher than that of the vibration plate so as to face the pressure generating chamber on the surface of the drive electrode. A second vibration that is located between the plate and the first vibration inducing plate on the surface of the common electrode, and is located in the vicinity of the partition wall that partitions the pressure generating chamber, and has a higher rigidity than the diaphragm. And to form a Okoshiban.

[0007]

Since the first vibration inducing plate having a higher rigidity than the vibrating plate is fixed on the upper surface of the region where the drive electrode is formed, the region bends so as to be convex on the surface side. Then, since it receives the reaction force of the second vibration inducing plate, which has a rigidity higher than that of the vibrating plate, on the back surface of the vibrating plate so as to be in contact with the first vibration inducing plate, the first vibration inducing plate is more than The amount of deflection is expanded.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. 1, 2, and 3
(A) and (B) each show an embodiment of the present invention, in which reference numeral 1 is a flow path unit, which is provided with a common ink chamber 3 and a nozzle opening 4, and has a communication hole 5 , 6, 7
The ink is supplied to the pressure generating chamber 8 of the actuator unit 2 described later via the ink, and the ink pressurized in the pressure generating chamber 8 is ejected from the nozzle opening 4 as an ink droplet.

In the flow path unit 1, a nozzle opening 4 is formed by forming a tapered through hole in the rust-proof steel or the like on the pressure generating chamber 8 side.
A nozzle plate 21 in which the ink is formed, a common ink chamber 3 and a common ink chamber forming substrate 10 in which a window or a through hole to be the communication hole 5 is formed by pressing in a non-rust steel having a predetermined thickness, and a pressure generating chamber 8 Communication substrate 1 having communication holes 5 located at both ends of the connection hole and communication holes 6 and 7 connected to the common ink chamber 3
1 and 1 are welded to each other via heat-welding films 12 and 13 such as a polyolefin film. Reference numeral 14 in the figure denotes a damper chamber formed in a region facing the common ink chamber 3.

On the other hand, the actuator unit 2 fixed to the flow path unit 1 has a pressure generating chamber forming substrate 20 forming a pressure generating chamber 8 and one of the pressure generating chamber forming substrate 20 and the common ink chamber 3 and the pressure generating chamber. 8, an ink supply port 21 that regulates the fluid resistance with the ink supply port 8, and an ink supply port formation substrate 23 that includes a communication hole 22 that connects the pressure generation chamber 8 and the nozzle opening 4, and the other surface of the pressure generation chamber formation substrate 20. And a vibration plate 24 that seals the same.

The vibrating plate 24 has a thickness P of about 10 μm.
As a plate made of a piezoelectric material such as ZT, a drive electrode 25 is formed by vapor deposition or sputtering of metal on the surface side, in a region facing the pressure generating chamber 8, as shown in FIG.

In the area where the pressure generating chamber 8 is deflected on the surface of the drive electrode 25, the rigidity of the diaphragm 24 is larger than that of the diaphragm 24 as shown in FIG. A strip-shaped first induced vibration plate 26 suitable for the above is formed by plating, sputtering, screen mask thick film printing, or the like. The width W1 of the vibration inducing plate 26 is smaller than the width W2 of the drive electrode, and the vibration inducing plate 26 is selected so as to extend over the entire pressure generating chamber 8. Further, the extraction electrode portion 26a is formed so as to be continuous with this and extend to a region outside the pressure generating chamber 8.

On the back surface of the diaphragm 24, as shown in FIG. 6, aluminum, copper, and chromium having ink resistance so as to cover the region where the pressure generating chambers 8, 8, 8 ... Are formed. The common electrode 27 is formed by forming metal layers such as.

On the surface of the common electrode 27, in the region located between the first vibration inducing plate 26, that is, in the vicinity of the partition 8a partitioning the pressure generating chamber 8, as shown in FIG. A strip-shaped second induction diaphragm 28 made of nickel, zirconium, or the like having corrosion resistance and having a thickness set so as to have higher rigidity than that of the diaphragm 24 is formed in accordance with the arrangement pitch of the pressure generating chambers 8. ing.

The vibrating plate 24 and the pressure generating chamber forming substrate 2
0 and the ink supply port forming substrate 23 are integrally laminated and formed as a unitary body in the process of firing into ceramics, and are fixed to the ink supply port forming substrate 11 of the flow path unit 1 by the heat-welding film 29 to be inkjet type. It is configured in a recording device.

In such a recording head, a common electrode 27 is formed by vapor deposition or sputtering on at least a region facing one side of the pressure generating chamber 8 on one surface of a green sheet of a piezoelectric material such as PZT which becomes a piezoelectric vibrating plate by firing. . Next, the partition wall 8a that partitions the pressure generating chamber 8 so that a gap is formed in a region facing the pressure generating chamber 8 on the surface of the common electrode 27.
The second vibration inducing plate 28 is formed at a position where the centers thereof face each other by metal thick film plating, sputtering, or thick film printing.

The member formed in the above-described process is provided on one surface of the pressure generating chamber forming substrate 20, and the pressure generating chamber forming substrate 2 is formed.
The ink supply port forming substrate 23 is bonded to the other surface of 0. In this state, since the drive electrode 25 and the first vibration inducing plate 26 are not formed on the surface of the vibration plate 24, the vibration plate 24 is not depressed or distorted in the pressure generating chamber 8, and the entire surface is not distorted. Can be uniformly pressed,
The layers can be bonded reliably.

The flow path unit 2 that does not have the drive electrode 25 and the first vibration inducing plate 26 to be built on the upper surface of the vibration plate 24 by firing the members thus joined together
The semi-finished product of is completed as a sintered body. And pressure generation chamber 8
Drive electrode 25 is formed by sputtering or vapor deposition of a conductive material on the surface so as to face to, and metal is vapor-deposited on the surface thereof, or first vibration inducing plate 26 is formed by thick film printing of ceramics or the like. .

Finally, the sintered body and the flow path unit 1 manufactured in another step in advance are adhered to each other by an adhesive agent, or a heat-welding film 29 is interposed between the two, thereby performing heat-welding. The recording head is completed by joining.

In this embodiment, when a drive signal is applied to the common electrode 27 and the drive electrode 25, the region facing the drive electrode 25 contracts in the width direction of the pressure generating chamber 8. However, since the first vibration inducing plate 26 having a rigidity higher than that of the vibrating plate 24 is fixed to the upper surface of the region where the drive electrode 25 is formed, as shown in FIG. Bend from the 8 side so that the outside is convex. And the first
The second vibration inducing plate 2 having a rigidity higher than that of the vibrating plate 24 on the back surface of the vibrating plate 24 so as to come into contact with the vibration inducing plate 26 of
Since the reaction forces of 8 and 28 are received, the amount of deflection is expanded as compared with the case where only the first vibration inducing plate 26 is used.

Thus, even if the volume of the pressure generating chambers must be reduced by the high density arrangement, the pressure generating chambers 8
The volume change rate can be increased, and ink droplets having an ink amount required for printing can be ejected.

In the embodiment described above, the first vibration inducing plate 26 is made of a conductive material such as metal, and one end of the first vibration inducing plate 26 is extended outside the region of the pressure generating chamber 8 to supply a drive signal. Although the pattern is formed, when the first vibration inducing plate 26 is made of an insulating material such as ceramic, a conductive pattern connected to the drive electrode 25 is formed to supply a signal to the drive electrode 25. Can be configured.

Further, in the above-described embodiment, the second vibration inducing plate 26 is formed as a continuous body which straddles the partition wall 8a which divides the pressure generating chamber 8. However, as shown in FIG. It is apparent that the same effect can be obtained by forming the two divided bodies 28a, 28a separated in the region facing the partition wall 8a so as to fit in the chamber 8.

[0024]

As described above, in the present invention, the first vibration inducing plate having a rigidity higher than that of the vibrating plate so as to face the pressure generating chamber is provided on the surface of the drive electrode, and the first vibrating plate is provided on the surface of the common electrode. Since the second vibration inducing plate having a higher rigidity than the vibrating plate is formed between the first vibration inducing plates and in the vicinity of the partition wall that divides the pressure generating chamber, the first vibrating plate is in contact with the first vibration inducing plate. As described above, by receiving the reaction force of the second vibration inducing plate having a rigidity higher than that of the vibrating plate on the back surface of the vibrating plate, the deflection amount can be increased as compared with the case of the first vibration inducing plate 26 alone. The generation chamber can be downsized, and high density array can be supported.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a flow path unit and an actuator unit separately according to an embodiment of the present invention.

3A and 3B are cross-sectional views showing cross-sectional structures in the longitudinal direction and the width direction of the pressure generating chamber, respectively.

FIG. 4 is a diagram showing an example of a drive electrode formed on the surface of an elastic plate.

FIG. 5 is a diagram showing an example of a first vibration inducing plate formed on the surface of a drive electrode.

FIG. 6 is a diagram showing an example of a common electrode formed on the back surface of an elastic plate.

FIG. 7 is a diagram showing an example of a second vibration inducing plate formed on the surface of the common electrode.

FIG. 8 is a view showing an expanded state of the pressure generating chamber in the same apparatus.

FIG. 9 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Flow Path Unit 2 Actuator Unit 3 Common Ink Chamber 4 Nozzle Opening 8 Pressure Generation Chamber 20 Pressure Generation Chamber Forming Substrate 21 Ink Supply Port 23 Ink Supply Port Formation Substrate 24 Vibration Plate 25 Drive Electrode 26 First Vibration Inducing Plate 27 Common Electrode 28 Second vibration inducing plate

Claims (5)

[Claims] 1. A vibrating plate made of a piezoelectric material, having a drive electrode on a front surface facing a pressure generating chamber and a common electrode on a back surface at least in a region facing the pressure generating chamber, and one surface thereof. A pressure generating chamber forming substrate that is sealed by the vibrating plate to form the pressure generating chamber, and the other surface of the pressure generating chamber forming substrate is sealed, and ink from a common ink chamber is generated to generate the pressure. An actuator unit composed of an ink supply port for supplying the ink to the chamber, an ink supply port forming substrate connecting the pressure generating chamber and the nozzle opening, and a nozzle opening for receiving ink from the pressure generating chamber and ejecting ink droplets And a flow path unit having the common ink chamber are integrally joined to each other, a surface of the drive electrode is opposed to the pressure generating chamber. As described above, the first vibration inducing plate having a rigidity higher than that of the vibrating plate and the first vibration inducing plate on the surface of the common electrode are positioned between the first vibration inducing plate and the partition wall partitioning the pressure generating chamber. A laminated ink jet recording head formed by forming a second vibration inducing plate having rigidity higher than that of the plate. 2. The laminated ink jet recording head according to claim 1, wherein the first vibration inducing plate is made of a conductive material, and one end of the first vibration inducing plate extends to an area outside the pressure generating chamber. 3. The laminated ink jet recording head according to claim 1, wherein the second vibration induction plate is formed in contact with the surface of the partition wall. 4. The stacked ink jet recording head according to claim 1, wherein the second vibration inducing plate is divided and formed so as to penetrate the partition wall. 5. A step of forming a common electrode on at least a region of one surface of the piezoelectric material facing the pressure generating chamber,
At a position facing a partition that partitions the pressure generating chamber so as to form a gap on the pressure generating chamber side on the surface of the common electrode,
A first step of forming a second vibration inducing plate, and a member formed in the first step on one surface of the pressure generating chamber forming substrate,
A second step of bonding the other surface to the ink supply port forming substrate and firing, a third step of forming a drive electrode on the surface so as to face the pressure generating chamber, and a step of forming a drive electrode on the surface of the drive electrode. The fourth step of forming a first vibration inducing plate, a nozzle opening for receiving ink from the pressure generating chamber and ejecting ink droplets, and a fourth flow path unit including a common ink chamber. A fifth step of joining the members formed in the step by heat welding, and a method of manufacturing a laminated ink jet recording head.