JPH091796A - Ink jet recording head - Google Patents

Abstract

PURPOSE: To provide an ink jet recording head capable of transmitting the displacement of a plurality of piezoelectric elements into the pressure chamber quite efficiently having no dispersion, and having even ink ejecting characteristics. CONSTITUTION: The recording head includes a substrate 9 with a plurality of ink flow passages 1 divided from an ink reservoir 7 via a filter flow passage 6, a vibration plate 10 covering these passages, and a piezoelectric element 12 being in press contact with the fixed position of the surface opposite to the ink pressure chamber 4 of the vibration plate, and the head is a plastic ink jet recording head formed so that ink is ejected from the nozzle by making use of electric field inductive distortion as a driving source in the direction parallel to the adhering surface of the piezoelectric element. The vibration plate 10 has a recess 10A with a predetermined dimensional allowance with respect to the outer periphery of the piezoelectric element 12 at the fixed position of the surface opposite to the ink pressure chamber 4, and the piezoelectric element 12 is adhered to the recess, holding an adhesive reservoir 15 therearound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is characterized by a printing device for a desk-top printer, a fax machine or the like, or an ink jet recording head used as a printing device, and particularly a displacement transmission mechanism portion of a piezoelectric element for obtaining good printing quality. The present invention relates to an inkjet recording head.

[0002]

2. Description of the Related Art Conventionally, a printing or printing method in which ink droplets are ejected from fine nozzles and spotted on a recording medium such as paper to record information is known as an ink jet recording method. On-demand type ink jet recording heads are known.

FIG. 3 is a cross-sectional view schematically showing an example of a conventional ink jet recording head in a direction along an ink flow path, and FIG. 4 is a plan view schematically showing an example of an ink flow path of a conventional ink jet recording head. Is. In the figure,
A substrate 9 made of a glass plate, a Si wafer, a metal plate, or a plastic molded product has a nozzle 2, a nozzle flow path 3, an ink pressurizing chamber 4, which are formed as concave grooves communicating with each other.
And a plurality of ink flow paths 1 each including an ink supply path 5,
This is provided with an ink reservoir 7 communicating with the backflow prevention filter channel 6, and a flat vibration plate 10 is airtightly joined or bonded to the seal surface 8 of the ink reservoir 7 to form a seal surface 8. And a plurality of ink flow paths 1 defined by the filter flow paths 6 and in which the flow direction of the ink is regulated is formed.
A common electrode 11 is formed on the surface of the vibrating plate 10 facing the ink pressurizing chamber 4 of the ink flow path 1 as a metal vapor deposition film or a printed film of a conductive coating material across the plurality of ink pressurizing chambers 4. In addition, the electrode 13 of the rectangular parallelepiped piezoelectric element 12 as an electromechanical conversion element is extremely thinly adhered to the portion of the common electrode 11 corresponding to each ink pressurizing chamber 4 so as to make conductive contact with the common electrode 11. Fixed by the agent layer 14,
An inkjet recording head is formed.

The ink jet recording head having the above-mentioned structure includes the other electrode 13 of the piezoelectric element 12 and the common electrode 1.
When a driving voltage of, for example, a square wave is applied between the piezoelectric element 12 and 1, the piezoelectric element 12 expands and contracts (electric field induced strain) in the plane direction parallel to the bonding surface. At this time, since the piezoelectric element 12 is in a state of being restrained by the vibration plate 10 via the adhesive layer 14 and the common electrode 11, the expansion and contraction of the piezoelectric element in the surface direction causes the vibration plate 1 to contract.
It is converted into a displacement in the direction perpendicular to 0, and the vibration plate is pushed and bent toward the ink pressurizing chamber side, and the volume of the ink pressurizing chamber is instantaneously reduced. Ink is ejected from the nozzle 2 through the nozzle flow path 3 and becomes an ink droplet, which is spotted on the opposite recording paper.
Printing is performed with an ink density of an amount proportional to the magnitude of the drive voltage applied to 2.

In order to print with the same density, it is required that the ejection characteristics such as the initial ejection velocity of ink droplets ejected from a plurality of nozzles and the ink droplet amount are uniform with respect to a constant drive voltage. In order to make the ejection characteristics uniform, first, the characteristics of the plurality of piezoelectric elements must be the same, and then a structure in which the displacement of the piezoelectric elements is transmitted to the ink pressurizing chamber with good response is required. Therefore, in the conventional ink jet recording head, when the piezoelectric element 12 is pressure-bonded to the vibration plate 10 via the common electrode 11, an adhesive having a triangular cross section that extends between the peripheral side surface of the piezoelectric element and the vibration plate. Forming a puddle 15,
The displacement of the piezoelectric element causes the vibration plate 10 to pass through the adhesive reservoir 15.
It is configured to be efficiently transmitted to. Further, in order for the displacement of the piezoelectric element to be efficiently and uniformly transmitted to the ink pressurizing chamber, the positional accuracy of the piezoelectric element with respect to the ink pressurizing chamber is a key. From this point of view, an inkjet recording head provided with a convex portion or a concave portion at a piezoelectric element bonding position on a vibration plate has been proposed by Japanese Patent Laid-Open No. 6-286137 in order to improve the positional accuracy when bonding the piezoelectric element. There is.

[0006]

In the conventional ink jet recording head shown in FIG. 3, the positioning accuracy of the piezoelectric element 12 with respect to the ink pressurizing chamber 4 is poor, and the transmission efficiency of the displacement of the piezoelectric element to the diaphragm varies. This is liable to occur, which causes a problem that the ejection characteristics of the ink droplets become uneven among the nozzles. Further, when the piezoelectric element 12 is pressure-bonded to the vibration plate 10 via the common electrode 11, even if the amount of the adhesive is controlled to be a constant amount, the vibration of the vibration plate 1 of the adhesive reservoir 15 is reduced.
It is difficult to control the spread to 0, and this causes a problem that a difference easily occurs between nozzles in the ejection characteristics of ink droplets. On the other hand, JP-A-6-286
In the inkjet recording head proposed in Japanese Patent No. 137,
The convex portion or the concave portion is provided for positioning the piezoelectric element, and the dimensional accuracy of the adhesive agent reservoir and its action are not mentioned.

An object of the present invention is to provide an ink jet recording head which can efficiently transfer the displacements of a plurality of piezoelectric elements to the ink pressurizing chamber without variations and therefore have uniform ink ejection characteristics.

[0008]

In order to solve the above-mentioned problems, a first aspect of the present invention relates to a series of ink pressurizing chambers, nozzle flow paths, and a series of ink pressurizing chambers branched from an ink reservoir via a filter flow path. A substrate provided with a plurality of ink flow paths formed of nozzles, a vibration plate covering the ink reservoir and the ink flow paths,
A rectangular parallelepiped piezoelectric element bonded at a fixed position on the surface of the vibrating plate facing the ink pressurizing chamber is provided, and ink is generated by using electric field induced strain in a direction parallel to the bonding surface of the piezoelectric element as a driving source. In the plastic ink jet recording head ejecting from the nozzle, the vibrating plate is provided with a concave portion having a predetermined dimensional margin with respect to the outer circumference of the piezoelectric element at a fixed position on the surface facing the ink pressurizing chamber. The piezoelectric element is adhered therein while holding a pool of adhesive around it.

According to the second aspect of the invention, the predetermined size of the recess is 1.05 to 1.2 with respect to the length of the short side and the length of the long side of the rectangular parallelepiped piezoelectric element. 0.2 to 0.5 with respect to the thickness of a rectangular parallelepiped piezoelectric element having a double size.
It is advisable to provide an adhesive reservoir having a size twice that of the piezoelectric element and bonded to the piezoelectric element in the range of 50 to 80% of the thickness of the piezoelectric element between the recess and the outer peripheral surface of the piezoelectric element.

According to the third aspect of the invention, the adhesive for the piezoelectric element forming the adhesive reservoir may be an ultraviolet / thermosetting adhesive. Further, the invention according to claim 4 is characterized in that the vibrating plate is made of a bonding material of a reinforcing metal plate and a plastic plate having a recess of a predetermined size at a fixed position on the surface facing the ink pressurizing chamber. It is advisable to adhere the plate side to the surface of the base material.

On the other hand, in the fifth aspect of the invention, the vibrating plate may be a metal plate having a recess of a predetermined size at a fixed position on the surface facing the ink pressurizing chamber.

[0012]

According to the first aspect of the invention, since the concave portion provided at a fixed position on the surface of the vibration plate facing the ink pressurizing chamber has a predetermined dimensional margin with respect to the outer circumference of the piezoelectric element,
In the process of bonding the piezoelectric element, the above-mentioned dimensional tolerance portion serves as an adhesive agent reservoir and restricts the spread of the adhesive agent on the surface of the diaphragm, so that the mechanical coupling state between the plurality of piezoelectric elements and the diaphragm is equalized. The electric field induced strain in the surface direction of the plurality of piezoelectric elements is evenly and efficiently transmitted to the ink pressurizing chamber through the vibrating plate. Therefore, it is possible to improve and equalize the ejection characteristics such as the ejection initial velocity of the ink droplets ejected from the plurality of nozzles and the amount of the ink droplets.

If the dimensions of the recess and the adhesive reservoir are maintained as in the second aspect of the present invention, the mechanical coupling state between the plurality of piezoelectric elements and the vibration plate is equalized, and the plurality of piezoelectric elements are provided. The electric field induced strain in the plane direction is uniformly and efficiently transmitted to the ink pressurizing chamber through the vibrating plate. Further, in the invention according to claim 3, since the adhesive of the piezoelectric element forming the adhesive reservoir is an ultraviolet / thermosetting combined type adhesive, the flow-out of the adhesive which occurs during curing only by heating is prevented. , The uniform shape of the adhesive pool formed by the surface tension of the adhesive can be retained and cured, and the constrained property of the piezoelectric element becomes appropriate and uniform. The characteristics can be made uniform.

Further, in the invention according to the fourth aspect, the vibrating plate is made of a laminated material of a metal plate having a recess and a plastic plate, so that the rigidity of the vibrating plate is increased and the displacement of the vibrating plate is efficiently performed. Since it can be transmitted to the ink pressurizing chamber, the displacement amount of the vibrating plate is increased, the ink ejection characteristics are further improved, and the strain recovery force of the vibrating plate is improved to increase the vibration period of the ink tip at the nozzle end face (called the meniscus period). ) Is shortened, it is possible to obtain an effect of suppressing a phenomenon (called a satellite) in which a fine ink droplet is accompanied by a main ink droplet when the ink droplet is ejected.

Furthermore, in the invention described in claim 5,
By using a metal plate with a recess of a predetermined size in a fixed position on the surface facing the ink pressurizing chamber, the rigidity of the vibration plate is improved and the displacement amount of the vibration plate is increased, resulting in ink ejection characteristics. Is further improved, and the meniscus period is shortened by improving the strain recovery force of the diaphragm, and the effect of suppressing the number of satellites is obtained.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
Since the members having the same reference numerals as those of the conventional example have the same functions as those of the conventional example, the description thereof will be omitted below. (Embodiment 1) FIG. 1 is a schematic sectional view showing an ink jet recording head according to Embodiment 1 of the present invention. In the figure, a substrate 9 in which the ink flow path 1, the filter flow path 6, and the ink reservoir 7 are formed as concave grooves is manufactured as a polyetherimide injection-molded product, and is placed at a fixed position on the surface facing the ink pressurizing chamber 4. A diaphragm 10 having a recess 10A in its
Is manufactured as a polyetherimide injection-molded product having a thickness of 0.35 mm so that the outer peripheral dimension thereof matches the outer peripheral dimension of the substrate 9. In addition, the concave portion 10 formed in the diaphragm 10
The size of A is determined by using the following formula as a guide in accordance with the size of the piezoelectric element 12 adhered thereto, and the position of the recess 10A is recessed in the center of the ink pressurizing chamber 4 with the outer peripheral surface of the diaphragm 10 as a reference. The centers of 10A are determined so that they coincide.

Length of short side of concave portion = length of short side of piezoelectric element × (1.05 to 1.2) Length of adjusting side of concave portion = length of long side of piezoelectric element × (1.05
~ 1.2) Depth of recess = thickness of piezoelectric element x (0.2 to 0.5) In this example, 3.0 x 1.5 x 0.1 as a piezoelectric element.
Since a 5 mm PZT piezoelectric element (relative permittivity = 5000) was used, the size of the recess 10A was 3.3 × 1.7 × 0.05.
mm.

The method of joining the vibrating plate and the substrate is such that the joining surface of both is exposed to chloroform vapor to form a swelling layer, and the two are superposed and sandwiched between flat plates to apply pressure. At this time, the concentration of chloroform vapor, the exposure time, the applied pressure, and the pressurization time were adjusted so that the thickness of the swelling layer was about 10 μm. Further, in order to remove the chloroform vapor remaining in the swollen layer, it was heated and dried in a state of being sandwiched between glass plates in a vacuum atmosphere.

The method of adhering the piezoelectric element to the concave portion is as follows. First, an aluminum thin film having a thickness of 1 μm as the common electrode 11 is sputter-deposited on the main portion of the vibration plate 10, and then a thermosetting epoxy resin system is formed on the common electrode of the concave portion. A certain amount of adhesive is dropped using a dispenser. In this state, the piezoelectric element is placed on the fixed position of the concave portion, and a predetermined load is applied to expel excess adhesive from the bonding surface. At this time, the expelled adhesive forms an adhesive pool 15 as shown in the figure due to its surface tension. Therefore, the adhesive is heated and cured at a predetermined temperature and time. The amount of adhesive dropped at this time is 50 to 8 of the thickness of the piezoelectric element 12 at the upper edge of the adhesive reservoir 15 shown in the figure.
The amount is set to 0% and suitable for bonding to the outer peripheral surface of the piezoelectric element. In this embodiment, 120 per piezoelectric element
A μcc adhesive was dropped. The piezoelectric element 12 and the recess 10A are bonded so that their long sides are parallel to the ink flow direction.

Table 1 is a data table showing the measurement results of the displacement amount of the vibrating plate of the ink jet recording head according to the first embodiment of the present invention and the ejection speed of ink droplets in comparison with that of the prior art. using 10 ink jet recording heads of the nozzle number 5 is a voltage value 100 V, data obtained by applying pulse width 80 [mu] s, a rectangular wave voltage of the displacement frequency 4KH _Z of the piezoelectric element in common as the driving voltage of the piezoelectric element. As a comparative example, as shown in FIG. 3, a head having no recess was used.

[0021]

[Table 1]

In Table 1, the displacement amount of the diaphragm is a value obtained by measuring the maximum displacement amount of the center of the piezoelectric element from the ink pressurizing chamber side, and the displacement amount of the diaphragm of the ink jet recording head according to the first embodiment has no recess. Is 10% higher than that of the head (comparative example). In the example, the displacement amount of the diaphragm is controlled by providing a concave portion in the diaphragm to control the positional accuracy of the piezoelectric element and the shape and size of the adhesive reservoir. And the standard deviation thereof is reduced to about two-thirds of that of the comparative example. Further, the ejection speed of the ink droplets indicates the initial speed of the ink droplets, and the standard deviation thereof in the example is reduced to about one third of that of the comparative example. From the above results, it was proved that this embodiment can provide an ink jet recording head in which the ink ejection characteristics are uniform between the ink jet recording heads and between the multi-nozzles, as compared with the related art.

(Embodiment 2) Table 2 is a data table showing the measurement results of the displacement amount of the vibration plate of the ink jet recording head and the ejection speed of ink droplets according to Embodiment 2 of the present invention. The difference from the first embodiment shown in FIG. 1 is that the piezoelectric element is bonded to the diaphragm by using an ultraviolet / thermosetting adhesive. Example 1 of the data of Table 2 is shown in Table 1
Compared with the data of, although there is no significant difference in the average value of the displacement of the diaphragm and the ejection speed of the ink droplets,
Each standard deviation is greatly reduced. From this, by using an ultraviolet / thermosetting type adhesive to make the shape and size of the adhesive reservoir more uniform as compared with the first embodiment, the ink droplet ejection characteristics are more uniform than those of the conventional one. It was demonstrated that an inkjet recording head was obtained. In addition, in this embodiment, the electric power required for the curing process of the adhesive can be saved more than the conventional one, and the yield can be improved, and the manufacturing cost of the inkjet recording head can be reduced.

[0024]

[Table 2]

(Embodiment 3) FIG. 2 is a sectional view schematically showing an ink jet recording head according to Embodiment 3 of the present invention. The difference between this embodiment and the first embodiment shown in FIG. 1 is that the vibrating plate 10 has a recess 10A of a predetermined size at a fixed position on the surface facing the ink pressurizing chamber 4, and the reinforcing metal plate 1 is provided.
0B and the plastic plate 10D are laminated by an adhesive layer 10C, and the plastic plate 10D side is bonded to the surface of the base material 9. That is, as the reinforcing metal plate 10B, a nickel plate having a thickness of 0.2 mm in which a recess 10A is formed by etching is used, and a hot melt adhesive having a thickness of 30 μm is formed between the reinforcing metal plate 10B and a plastic plate 10D made of polyetherimide having a thickness of 0.05 mm. A predetermined surface pressure was applied in the state of interposing the above to heat and bond so that the thickness of the adhesive layer became uniform. In addition, except that the reinforcing metal plate 10B also has the function of the common electrode, the method of determining the recess 10A, the method of joining the substrate 9 and the like are the same as those in the embodiment shown in FIG.

Table 3 is a data table showing the measurement results of the displacement amount of the vibrating plate of the ink jet recording head shown in FIG. 2 and the ejection speed of the ink droplets in comparison with that of the prior art, and Table 4 is the ink jet recording head shown in FIG. 3 is a data table showing the measurement result of the meniscus period of the diaphragm of FIG. 3 in comparison with that of the conventional technique, and the measurement conditions are the same as those in Table 1. Table 5 is a data table showing the results of measuring the number of satellites of the inkjet recording head shown in FIG. 2 in comparison with that of the inkjet recording head of Example 1 (head without a metal plate). The number of satellites per 100 dots is shown for five recording heads.

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

In Table 3, both the displacement amount of the vibrating plate of the head of the third embodiment and the ejection amount of the ink droplets are about 30% larger in average value than the conventional head having no recess (head shown in FIG. 3). ing. It is considered that this is because the rigidity of the diaphragm is improved by the reinforcing metal plate made of a nickel plate. On the other hand, the standard deviation of the average value is smaller than that of the conventional head, but the standard deviation is slightly larger than those of the first and second embodiments. It is considered that this is because the diaphragm was made of a laminated material, and thus the variation in data was slightly increased due to the existence of the adhesive layer. On the other hand, in Table 4, in the head of Example 3 while the meniscus period in the conventional head without recess is 241μs close to the displacement cycle of the piezoelectric element _{(1 / 4kH Z = 250μs)} 19
It is shortened to 7 μs, which shows that the displacement recovery is faster due to the improvement of the rigidity of the diaphragm. The effect of shortening the meniscus cycle is clearly shown as the effect of reducing the number of satellites in Table 5, and Example 1 shown as a comparative example.
The number of satellites of the head of No. 3 is 29, while that of the head of Example 3 is reduced to 3.1, which shows that it is possible to prevent the print quality from being deteriorated by the satellites attached to the main ink droplets. . From the above measurement data, by reinforcing the rigidity of the diaphragm by adhering the reinforcing metal plate with the recess to the plastic diaphragm, not only the ink ejection characteristics but also the print quality is higher than that of the conventional head. It was proved that a multi-nozzle type ink jet recording head that was completed in 1 can be obtained.

(Embodiment 4) Table 6 is a data table showing the measurement results of the displacement amount of the vibrating plate of the ink jet recording head and the ejection speed of ink droplets according to Embodiment 4 of the present invention. This embodiment is different from the embodiment 1 shown in FIG. 1 in that the vibrating plate 10 is provided with a recess 10A having a predetermined size at a fixed position on the surface facing the ink pressurizing chamber 4 (in this case, nickel). Plate) and is bonded to the surface of the base material 9 using a hot melt adhesive having a thickness of 30 μm. That is, the structure is such that the plastic plate 10D in FIG. 2 is removed and the reinforcing metal plate 10B is directly bonded to the substrate 9. In the case of the fourth embodiment, the depth of the ink flow path 1 is formed to be deeper by about 20 μm in consideration of the hot melt adhesive entering the ink flow path. In addition, the heating conditions during adhesion were controlled more gently than in Example 3. In addition,
The measurement conditions in Table 6 were the same as those in Example 1.

[0032]

[Table 6]

Comparing the data of Table 6 with the data of Table 3 (Example 3), the average value of the displacement of the diaphragm is increased by about 20%. It is considered that this is because the adhesive layer 10C necessary for bonding the reinforcing metal plate and the plastic plate in Example 3 is eliminated, and the displacement of the piezoelectric element is directly transmitted to the ink pressurizing chamber. On the other hand, the ink ejection speed has a larger standard deviation of the data as compared with the third embodiment because the hot melt adhesive layer is present on the sealing surface with the substrate. However, it shows excellent characteristics compared to the conventional inkjet recording head without recesses, and the manufacturing process can be reduced because the joining process with chloroform vapor and the diaphragm made of polyesterimide as in Examples 1 and 3 are unnecessary. Therefore, it is possible to economically provide an inkjet recording head with moderate specifications of printing quality.

[0034]

As described above, the ink jet recording head of the present invention has a strong tendency that the displacement amount of the vibration plate and the ejection speed of the ink droplets depend on the displacement transmission mechanism portion of the piezoelectric element. By using a certain dimensional margin provided between the recess and the outer peripheral surface of the diaphragm, it was configured to suppress variations in the shape and dimensions of the adhesive reservoir. As a result, it is possible to improve the displacement amount of the vibrating plate and the average value of the ink droplet ejection speed and to significantly reduce the standard deviation, as compared with the conventional head having no concave portion, and therefore, there is no unevenness in the ink ejection characteristics and it is high. It is possible to provide an inkjet recording head that can obtain printing quality.

Further, by using the ultraviolet / thermosetting adhesive for bonding the piezoelectric element, it becomes possible to further reduce the displacement amount of the vibration plate and the standard deviation of the ink droplet ejection speed, and the ink ejection characteristics. It is possible to provide an ink jet recording head which has less unevenness of printing and can obtain higher printing quality. Furthermore, if the vibrating plate is a bonding material of a reinforcing metal plate having a recess and a plastic plate, the effect of improving the displacement amount of the vibrating plate and the average value of the ejection speed of ink drops, and the effect of reducing the number of satellites can be obtained. Therefore, it is possible to provide an ink jet recording head having high ink droplet ejection characteristics and high printing performance.

Furthermore, by forming the vibrating plate as a metal plate having a concave portion, an ink jet recording head having a higher displacement amount of the vibrating plate and an average value of ink droplet ejection speed and excellent ink droplet ejection characteristics can be obtained. It can be economically provided by a simplified manufacturing process.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing an inkjet recording head according to a first embodiment of the present invention.

FIG. 2 is a sectional view schematically showing an inkjet recording head according to a third embodiment of the present invention.

FIG. 3 is a sectional view schematically showing an example of a conventional inkjet recording head in a direction along an ink flow path.

FIG. 4 is a plan view schematically showing an example of an ink flow path of a conventional inkjet recording head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink flow path 2 Nozzle 3 Nozzle flow path 4 Ink pressurizing chamber 5 Ink supply path 6 Filter flow path 7 Ink pool 8 Sealing surface 9 Substrate 10 Vibration plate 10A Recess 10B Reinforcing metal plate 10C Adhesive layer 10D Plastic plate 11 Common electrode 12 Piezoelectric element 13 Electrode 14 Adhesive layer 15 Adhesive reservoir

Claims (5)

[Claims] 1. A substrate having a plurality of ink pressurization chambers branched from an ink reservoir via a filter channel, a nozzle channel, and a plurality of ink channels consisting of nozzles, and a vibration covering the ink reservoir and the ink channel. A plate and a rectangular parallelepiped piezoelectric element bonded at a fixed position on the surface of the vibration plate facing the ink pressurizing chamber, and a driving source for electric field induced strain in a direction parallel to the bonding surface of the piezoelectric element. In the plastic ink jet recording head for ejecting ink from the nozzle as described above, the vibrating plate is provided with a concave portion having a predetermined dimensional margin with respect to the outer circumference of the piezoelectric element at a fixed position on the surface facing the ink pressurizing chamber. An ink jet recording head characterized in that the piezoelectric element is adhered to the inside of the concave portion while holding an adhesive reservoir around the piezoelectric element. 2. The ink jet recording head according to claim 1, wherein the predetermined size of the concave portion is 1.05 to 1.5 with respect to the length of the short side and the length of the long side of the rectangular parallelepiped piezoelectric element.
The piezoelectric element has a size twice as large as that of the rectangular parallelepiped piezoelectric element and is 0.2 to 0.5 times the thickness of the rectangular parallelepiped piezoelectric element, and the thickness of the piezoelectric element is between the recess and the outer peripheral surface of the piezoelectric element. 50 to 80
An ink jet recording head having an adhesive reservoir bonded to a piezoelectric element in the range of%. 3. The inkjet recording head according to claim 1, wherein the adhesive of the piezoelectric element forming the adhesive reservoir is an ultraviolet / thermosetting adhesive. 4. The ink jet recording head according to claim 1, wherein the vibrating plate has a recessed portion of a predetermined size at a fixed position on the surface facing the ink pressurizing chamber, and the vibrating plate is made of a laminated material of a reinforcing metal plate and a plastic plate. The inkjet recording head is characterized in that the plastic plate side is adhered to the surface of the base material. 5. The ink jet recording head according to claim 1, wherein the vibrating plate is a metal plate having a recess of a predetermined size at a fixed position on the surface facing the ink pressurizing chamber. Recording head.