JPH0550594A - Ink jet printer head - Google Patents

Abstract

PURPOSE:To obtain a printer head having a good productivity by a method wherein a drive plate formed into a flat plate by successively providing electrodes and non-piezoelectric members on the both ends of piezoelectric members is prepared, and the non-piezoelectric members of the drive plate are fixed to a body plate. CONSTITUTION:An ink jet printer head 16 is formed by integrally bonding a thick body plate 18 to a thin drive plate 19. In the body plate 18, a plurality of recessed parts each connected to an orifice 17 and an ink supply path are provided in an array form. At this time, in the drive plate 19, a non-piezoelectric member 22 is provided between electrodes 21 formed on both ends of piezoelectric members 20. The drive plate 19 is bonded to the body plate 18 at positions of the non-piezoelectric members 22, whereby pressure chambers 23 are formed. In this manner, since the drive plate 19 is bonded to the body plate 18 with the non-piezoelectric members 22, the non-piezoelectric members 22 and the electrodes 21 are improved in material selectability and adhesion. In addition, the electrodes 21 are not required to be formed thick and improved in productivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-demand type ink jet printer head.

[0002]

2. Description of the Related Art At present, as an inkjet printer head capable of quiet and high-density printing, an inkjet printer head for ejecting ink droplets from an orifice to fix the ink onto a printing paper has been put into practical use.

For example, an on-demand type ink jet printer head has a structure in which a pressure generating means at least the surface of which is displaceable is provided in a pressure chamber communicating with each of the orifices arranged in an array. Then, in such an inkjet printer head, the pressure generating means is vibrated by the drive power corresponding to the print image, and the ink in the pressure chamber is ejected as an ink droplet from the orifice.

At present, it has been proposed to use a pre-polarized piezoelectric member as the pressure generating means of the ink jet printer head as described above. As illustrated in FIG. 5, the piezoelectric member 1 is a member which, when an electric field is applied at a right angle to a preset polarization direction, is deformed only in the polarization direction without expanding or contracting in the energizing direction. Such skid deformation is called shear mode deformation. The illustrated piezoelectric member 1 exemplifies a case where the electrodes 2 are provided at both ends and the left end is fixed. However, for example, when the lower edge of the piezoelectric member 1 is fixed, lateral slip deformation occurs only in the left-right direction. It can also occur. It should be noted that such a piezoelectric member 1 is arranged such that when the polarization direction or the energization direction is reversed, the deformation direction is also reversed.

An ink jet printer head using such a piezoelectric member is USP4584590, USP482.
5227 and the like, the inkjet printer heads disclosed in these specifications all cause crosstalk due to unnecessary deformation of the piezoelectric member such as longitudinal vibration mode or lateral vibration mode. Have the challenges of.

Therefore, an ink jet printer head disclosed in Japanese Patent Laid-Open No. 3-49957 will be described as an apparatus which solves such a problem with reference to FIGS. 6 and 7. As shown in FIG. 6, the ink jet printer head 3 includes a thin plate-shaped drive plate 6 in which electrodes 4 formed of thermistors and piezoelectric ceramics 5 that are piezoelectric members are alternately formed, an orifice, and an ink supply path. A thick plate-shaped main body plate 7 in which a plurality of recesses (not shown in the drawing) communicate with each other are continuously formed in an array, and these plates 6 and 7 are integrally bonded with an adhesive 8. The pressure chamber 9 is formed by shielding the concave portion with a pair of the piezoelectric ceramics 5.

A method of manufacturing the driving plate 6 of the ink jet printer head 3 will be described with reference to FIG. First, a lead zirconate titanate-based ceramics material 10 forming the piezoelectric ceramics 5 and a barium titanate-based ceramics material 11 forming the electrodes 4 are each formed into a sheet by a doctor blade method or the like,
As illustrated in (a), the layers are alternately laminated and thermocompression bonded, and then cut into a predetermined size or the like and integrally fired. By doing so, a ceramic mass 12 in which the piezoelectric ceramics 5 and the electrodes 4 are alternately laminated can be obtained.
As illustrated in (b), the ceramic plate 13 having the same shape as the drive plate 6 is formed by cutting the plate at a right angle to the stacking direction. Since the polarization direction of the piezoelectric ceramics 5 is random at this stage in this ceramic plate 13, as shown in FIG.
Plate electrodes 14 and 15 are attached to the cut surface of No. 2, and electricity is supplied in a temperature region lower than the Curie temperature of the piezoelectric ceramic 5 and higher than the Curie temperature of the electrode 4. By doing so, the electrode 4 made of the thermistor material is kept within this temperature range.
Is an insulator and the piezoelectric ceramic 5 has conductivity,
It is possible to obtain the drive plate 6 in which only the piezoelectric ceramic 5 is favorably polarized.

[0008]

In the ink jet printer head 3 disclosed in the above publication, since the ink in the pressure chamber 9 is satisfactorily pressed by the piezoelectric ceramics 5, the drive plate 6 is placed at the position of the electrode 4 and the main plate It has a structure to be joined to 7.

Therefore, in this ink jet printer head 3, the electrode 4 of the drive plate 6 needs to be a thermistor material in order to realize the polarization of the piezoelectric ceramics 5, and the selectivity of the material is low, and the main plate The method of joining with 7 tends to be limited to adhesion or the like. Further, in this inkjet printer head 3, it is necessary to form the electrode 4 of the drive plate 6 thickly to about 100 (μm) in order to improve the bonding with the body plate 7.
It is difficult to form the electrode 4 having such a thickness by a thin film technique such as sputtering or vapor deposition. That is, in the inkjet printer head 3 described above, it is actually difficult to form each part and the productivity is reduced.

The present invention provides an ink jet printer head having good productivity.

[0011]

The invention according to claim 1 is
A main body plate is provided in which a plurality of recesses in which the orifices and the ink supply paths communicate with each other are arranged in an array, and a pair of pre-polarized piezoelectric members are located on the recesses of the main body plate to form pressure chambers. In an inkjet printer head in which ink that is formed and held in a pressure chamber and held in a pressure chamber is pressed by a piezoelectric member that is deformed according to applied power and ejected from an orifice, electrodes are provided at both ends of the piezoelectric member. And a non-piezoelectric member are sequentially arranged to provide a plate-shaped drive plate, and the non-piezoelectric member of the drive plate is fixed to the main body plate.

According to the second aspect of the present invention, the pair of piezoelectric members located on the pressure chamber are polarized in the same direction.

According to the third aspect of the invention, the pair of piezoelectric members located on the pressure chamber are polarized in different directions.

[0014]

By providing the drive plate formed in a flat plate shape by sequentially disposing the electrodes and the non-piezoelectric member on both ends of the piezoelectric member, and fixing the non-piezoelectric member of the drive plate to the main body plate, An inkjet printer head with good productivity can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claims 1 and 2 will be described with reference to FIG. In this ink jet printer head 16, a thick plate-shaped main plate 18 in which a plurality of recesses, each communicating with an orifice 17 and an ink supply path (not shown), are continuously arranged in an array, and a thin drive plate 19 are provided. It has a structure that is integrally joined. Here, the drive plate 19 has a structure in which a non-piezoelectric member 22 is provided between electrodes 21 formed at both ends of the piezoelectric member 20, and the drive is performed at the position of these non-piezoelectric members 22. The pressure chamber 23 is formed by adhering the plate 19 to the body plate 18.

In this ink jet printer head 16, the piezoelectric members 20 in the drive plate 19 are all polarized in the same direction, and the pair of piezoelectric members 20 located on one pressure chamber 23 has no polarization. Power is supplied in different directions. In addition, such a piezoelectric member 20 is arranged on the main body plate 1 in the front-back direction in the drawing.
It is necessary to seal without fixing to 8, but this can be realized by an adhesive or film having elasticity.

In the ink jet printer head 16 having such a structure, when the ink 24 supplied from the ink supply path is held in the pressure chamber 23, electricity is supplied between the predetermined electrodes 21. like,
The pair of piezoelectric members 20 on the pressure chamber 23 undergoes shear mode deformation, and the ink 24 is ejected from the orifice 17.

Here, in the ink jet printer head 16, since only the shear mode deformation occurs in the driven piezoelectric member 20, the occurrence of crosstalk is prevented.

In the ink jet printer head 16, the non-piezoelectric member 22 of the drive plate 19 joined to the body plate 18 is made of polyethylene, polyacetal, polyamide, polypropylene, ultra-high polymer HDPE (High-Density Polyethylene) or the like. As described above, a resin material that can be easily heat-bonded to the body plate 18 at a low temperature can be used. As the non-piezoelectric member 22 and the electrode 21 located on the pressure chamber 23, the electrode 21 such as polyacetal or polyethylene terephthalate can be used. It is possible to use a resin material that is easily heat-bonded to the piezoelectric member 20 at low temperature. An epoxy thermosetting adhesive or a photo-curing adhesive is used as the adhesive for adhering the members 21, 22 to the other members 18, 20, 21, etc., as described above. Conductivity can be imparted to the electrode 21 and the non-piezoelectric member 20 by mixing a conductive filler in such a resin material or adhesive.

By doing so, in the ink jet printer head 16, the drive plate 19 is joined to the main body plate 18 by the non-piezoelectric member 22, so that the selectivity of the material of the non-piezoelectric member 22 and the electrode 21 is improved. It is expensive, and various joining methods such as adhesion and fusion can be carried out. Further, in this inkjet printer head 16, since it is not necessary to form the electrode 21 of the drive plate 19 to be thick, the productivity is extremely good.

In this embodiment, the ink jet printer head 16 in which the pair of piezoelectric members 20 located on the pressure chamber 23 are polarized in the same direction as in the first and second aspects of the invention has been exemplified. An ink jet printer head 26 in which a pair of piezoelectric members 20 located on a pressure chamber 23 are provided with drive plates 25 polarized in different directions, as in the invention described in claims 1 and 3 illustrated in FIG. Can also be implemented. In this case, in the inkjet printer head 26, the pair of driven piezoelectric members 2
Since 0 is energized in the same direction, simplification of the wiring structure can be realized.

An example of a method for manufacturing the drive plate 19 in which the piezoelectric members 20 have the same polarization direction as described above will be described with reference to FIG. First, as illustrated in FIG. 2A, the block-shaped piezoelectric member 20 is polarized in advance,
As illustrated in (b), a recessed groove 30 parallel to the polarization direction P is continuously formed by dicing or the like to form a comb tooth shape.
Then, as illustrated in FIG. 3C, the electrodes 21 are formed in the concave grooves 30 of the piezoelectric member 20 by electroless plating or the like, and the non-piezoelectric member 22 is filled between these electrodes 21. Here, as a specific method of filling the non-piezoelectric member 22 in such a gap, a liquid resin material is made to flow and cured, or a thin plate-shaped non-piezoelectric member 22 is press-fitted and fixed. Etc. are possible. Next, as illustrated in FIG. 3D, the upper and lower parts of the piezoelectric member 20 in which the grooves 30 are filled with the members 21 and 22 as described above are removed by cutting, cutting, or the like. As illustrated in (e), by cutting the piezoelectric member 20 in a direction orthogonal to the polarization direction P, as shown in (f) of FIG. The production of the plate 19 is completed. In addition, such a drive plate 19 is actually adjusted to a desired size by polishing or cutting.

An example of a method of manufacturing the drive plate 25 in which the polarization directions of the piezoelectric members 20 are different will be described with reference to FIG. First, as illustrated in FIG. 3A, the groove 31 is continuously connected to the flat plate-shaped piezoelectric member 20 in advance by dicing or the like to form the whole into a comb-teeth shape. As described above, the electrodes 33 are provided on the upper and lower surfaces orthogonal to the continuous direction of the comb-tooth-shaped column portion 32 by electroless plating, sputtering or the like, and polarization is performed in different directions alternately. At this time, this polarization can be performed in the same direction, but in the case of performing it in the same direction, it is more productive to perform the polarization before the comb teeth are formed. Then, as illustrated in FIG. 7C, the electrode 33 is removed by polishing or the like after completion of such polarization, and as illustrated in FIG. 7D, the piezoelectric member 20 is formed by electroless plating or the like. The electrode 21 is formed in the concave groove 31. Next, as illustrated in FIG. 6E, a non-piezoelectric member 22 is filled between these electrodes 21, and the recessed groove 31 is formed in each member 21 and 22 as illustrated in FIG. By removing the end portion of the filled piezoelectric member 20 by cutting, cutting, or the like, the manufacture of the flat drive plate 25 in which the polarization directions of the piezoelectric members 20 are different is completed.

By doing so, the drive plates 19, 25 and the like can be easily obtained, and the productivity of the ink jet printer heads 16, 26 can be improved.

[0025]

According to the first aspect of the present invention, there is provided a main body plate in which a plurality of concave portions each having an orifice and an ink supply path communicating with each other are connected in an array, and the concave portions of the main body plate are pre-polarized. A pair of piezoelectric members are respectively positioned to form a pressure chamber, and the ink supplied from the ink supply path and held in the pressure chamber is pressurized by a piezoelectric member that is deformed according to the applied power and ejected from the orifice. In an inkjet printer head, a drive plate formed in a flat plate shape by sequentially disposing electrodes and non-piezoelectric members on both ends of the piezoelectric member is provided, and the non-piezoelectric member of the drive plate is fixed to the main body plate. As a result, the material selectivity of the non-piezoelectric member and the electrode is good, and the degree of freedom of the joining method between the non-piezoelectric member and the main body plate is also good, and the productivity is good Those having an effect such as can be obtained inkjet printer head.

According to the second aspect of the invention, the pair of piezoelectric members located on the pressure chambers are polarized in the same direction, so that a practical inkjet printer head can be obtained with a simple structure. Is to have.

According to the third aspect of the invention, the pair of piezoelectric members located on the pressure chamber are polarized in different directions, so that a practical inkjet printer head can be obtained with a simple structure. Is to have.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the invention described in claims 1 and 2. FIG.

FIG. 2 is a vertical sectional front view showing an embodiment of the invention described in claims 1 and 3. FIG.

FIG. 3 is a process chart showing an example of a method of manufacturing a drive plate.

FIG. 4 is a process drawing showing another example of a method of manufacturing a drive plate.

FIG. 5 is a schematic view showing the operating principle of the piezoelectric member.

FIG. 6 is a vertical sectional front view showing a conventional example.

FIG. 7 is a process chart showing a method of manufacturing a drive plate.

[Explanation of symbols]

 16, 26 Inkjet printer head 17 Orifice 18 Main body plate 19, 25 Drive plate 20 Piezoelectric member 21 Electrode 22 Non-piezoelectric member 23 Pressure chamber 24 Ink

Claims (3)

[Claims] 1. A main body plate in which a plurality of recesses, each communicating with an orifice and an ink supply path, are connected in an array, and a pair of pre-polarized piezoelectric members are located on the recesses of the main body plate. An ink-jet printer head configured to form a pressure chamber, press the ink supplied from the ink supply path and held in the pressure chamber with the piezoelectric member that is deformed according to applied power, and eject the ink from the orifice. A driving plate formed in a flat plate shape by sequentially disposing electrodes and a non-piezoelectric member on both ends of the piezoelectric member, and fixing the non-piezoelectric member of the driving plate to the main body plate. And inkjet printer head. 2. The ink jet printer head according to claim 1, wherein a pair of piezoelectric members located on the pressure chamber are polarized in the same direction. 3. The ink jet printer head according to claim 1, wherein a pair of piezoelectric members located on the pressure chamber are polarized in different directions.