JPH05254132A - Inkjet printer head manufacturing method - Google Patents

Abstract

(57) [Summary] [Object] To realize a manufacturing method for improving the driving efficiency and productivity of piezoelectric members in a Gould-type inkjet printer head. A piezoelectric member 14 having a large number of voids continuous in an array is formed by molding a piezoelectric ceramic, a common electrode 17 is provided on the outer surface of the piezoelectric member 14, and voids 8 and 10 are formed.
By alternately providing the individual electrodes 15 and the common electrode 16 on the inner surface of the, the common electrodes 16 and 17 are positioned in the substantially entire circumferential direction of the void 8 which becomes the pressure chamber 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet printer head called a Gould method or the like.

[0002]

2. Description of the Related Art At present, as a printer capable of quiet and high-density printing, an ink jet printer or the like, which ejects ink droplets from an orifice to fix it on a printing paper, has been put into practical use.

For example, in an ink jet printer head called a Gould method or the like, a common electrode is formed on the outer surface of a piezoelectric member which is formed into a tubular shape and is polarized in the radial direction, and an individual electrode is provided on the inner surface of the piezoelectric member. The structure is such that a pressure chamber in which the orifice and the ink supply path communicate with each other is formed in the space located inside the electrode, and the ink in the pressure chamber is pressurized by the radial contraction of the piezoelectric member due to the energization between the electrodes to cause the orifice. It is designed to eject ink droplets from.

However, in practice, if the above-mentioned tubular piezoelectric members are individually manufactured and continuously arranged in an array, it is difficult to increase the density and the productivity is lowered. Therefore, JP-A-62-73951 discloses the method. As shown in FIG. 5, the piezoelectric member 1 of the disclosed inkjet printer head has a large number of through holes 3 arranged in an array inside the elongated piezoelectric member 2 and arranged at positions between these through holes 3. The structure is such that a concave groove 4 is formed on the outer surface, a common electrode (not shown) is provided on the outer surface continuous to the inside of the concave groove 4, and an individual electrode (not shown) is provided in the through hole 3.

By doing so, in the main body plate 1 of this ink jet printer head, since a large number of through holes 3 each functioning as a pressure chamber are connected to one piezoelectric member 2, the productivity is good. It is also possible to increase the pressure chamber density.

Further, although the above publication does not disclose a specific example of the material of the piezoelectric member 2 of the body plate 1 or a molding method, for example, at present, as the material of the body plate 1 as described above, corrosion resistance and strength are used. It has been proposed to use good piezoelectric ceramics.

[0007]

In the ink jet printer head disclosed in the above publication, one piezoelectric member 2 is used.
By continuously providing the through holes 3 to be the pressure chambers, the productivity of the main body plate 1 is good and the pressure chambers can be made high in density.

However, in the main body plate 1 of this ink jet printer head, the common electrode surrounds the individual electrode of the through hole 3 by forming the concave groove 4 on the outer surface of the piezoelectric member 2. The common electrode is through hole 3
Since the piezoelectric members 2 are located substantially on both sides of this, the piezoelectric member 2 contracts in the left-right direction in the drawing. That is, in the main body plate 1 of the inkjet printer head, the through hole 3 of the piezoelectric member 2 forming the pressure chamber cannot be contracted in the entire circumferential direction, so that the driving efficiency thereof tends to decrease and the power consumption tends to increase. is there.

Further, as mentioned above, the above publication does not disclose a specific example of the material and the forming method of the piezoelectric member 2, but
When this is manufactured by the dicing process or the like of the piezoelectric ceramic flat plate base material, it is difficult to increase the processing speed, so that the productivity is reduced.

The present invention provides a method of manufacturing an ink jet printer head having good driving efficiency and productivity.

[0011]

A common electrode is formed on the outer surface of a piezoelectric member that is formed in a tubular shape and is polarized in the radial direction, and an individual electrode is provided on the inner surface of the piezoelectric member. A pressure chamber in which the orifice and the ink supply path communicate with each other is formed, and the ink in the pressure chamber is pressurized by the contraction of the piezoelectric member in the radial direction due to the energization between the electrodes so that the ink droplet is ejected from the orifice. In an ink jet printer head, a piezoelectric member is formed by molding a piezoelectric ceramic to form a continuous array of piezoelectric members, and a common electrode is provided on the outer surface of the piezoelectric member and individual electrodes and common electrodes are alternated on the inner surface of the void. It was set up in.

[0012]

[Function] Since a large number of pressure chambers can be continuously arranged in one die-molded piezoelectric member, this piezoelectric member has good productivity, and the pressure chambers can be easily densified. Since the common electrode can be positioned substantially in the entire circumferential direction of the formed pressure chamber, the driving efficiency of the piezoelectric member can be improved, which can contribute to the productivity improvement and the power saving of the inkjet printer head. ..

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. First, in the inkjet printer head 5 of this embodiment, as illustrated in FIG. 2, an orifice plate 7 in which orifices 6 are continuously arranged in an array, a pressure chamber 9 including a through hole 8 which is a square void, and a rectangle. Body plate 1 in which through holes 10 that are voids are alternately formed
1 and a supply path plate 13 in which ink supply paths 12 that merge into one on the way are connected in an array in sequence, and the orifice 6, the pressure chamber 9, and the ink supply path are connected. 12 communicate with each other. The piezoelectric member 14 forming the main body plate 11 is formed by injection molding, which is one of the molding methods for piezoelectric ceramics, and is polarized in the radial direction centered on each of the pressure chambers 9. An individual electrode 15 is formed on the inner surface of the through hole 8 forming the pressure chamber 9, and common electrodes 16 and 17 are formed on the outer surface of the other through hole 10 and are electrically connected to each other.

In the ink jet printer head 5 having such a structure, driving power is supplied to the electrodes 15 to 17.
The piezoelectric member 14 of the main body plate 11 expands and contracts around the pressure chamber 9 when electricity is applied to the ink in the pressure chamber 9.
(Not shown) is pressurized and discharged from the orifice 6.

An example of a method of manufacturing the body plate 11 of the ink jet printer head 5 as described above will be described in detail below. First, when the piezoelectric ceramic of the piezoelectric member 14 is formed of PZT (Lead Zirco Titanate), a ceramic raw material composed of TiO ₂ , PbO, ZrO ₂ and a characteristic improving agent is mixed and dried, and then calcined. Knead with an organic binder. Then, a powder, which is a molding material formed by crushing the powder, is injected into a mold having a predetermined shape by an injection molding machine to form a molded product (green molded body). Therefore, by volatilizing the organic components in the molded product in a degreasing furnace and then firing (main sintering), square and rectangular through holes 8 and 10 are alternately formed as illustrated in FIG. 1 (a). The formed rectangular parallelepiped piezoelectric member 14 is formed.

The piezoelectric member 14 thus formed by injection molding, which is one of the molding processes, is subjected to finishing processing such as polishing if desired, and as shown in FIG.
The electrodes 15 to 17 are formed on each part of the piezoelectric member 14 by the existing thin film technology, and then placed in the silicone oil of 80 to 120 (° C.). Therefore, by applying an electric field of 2 to 5 (kV / mm) between the individual electrode 15 and the common electrodes 16 and 17 in this state, the piezoelectric member 14 is polarized in the radial direction around the pressure chamber 9. To be done. The piezoelectric member 14 as described above
Can also be carried out in a ternary system in which a complex perovskite oxide is added to the binary system of PZT.

By doing so, in the ink jet printer head 5, the pressure chamber 9 is continuously provided in one piezoelectric member 14 made of injection-molded piezoelectric ceramic, so that the productivity of the piezoelectric member 14 is increased. The pressure chamber 9 is good, and the density of the pressure chamber 9 can be easily increased. Further, the common electrodes 16 and 17 are formed substantially in the entire circumferential direction of the pressure chamber 9 in which the individual electrodes 15 are formed on the inner surface.
Is located, the piezoelectric member 14 has good driving efficiency and can contribute to power saving of the inkjet printer head 5.

Further, in the ink jet printer head 5 as described above, the orifice 6, the plates 7 and 13 for forming the ink supply path 12 and the like are also formed by injection molding of ceramic, so that productivity, shape accuracy and durability are improved. Improvements can also be implemented. In the inkjet printer head 5, since the piezoelectric member 14 has a uniform cross-sectional shape, it can be manufactured by extrusion molding as well as injection molding.

Next, a second embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 4, the inkjet printer head 18 of the present embodiment includes an orifice plate 7 in which orifices 6 are arranged in an array,
The piezoelectric member 20 divided into the pressure chambers 19 is connected to the insulating substrate 21.
The structure is such that the main body plate 22 mounted on the upper side and the supply path plate 13 in which the ink supply paths 12 that merge into one on the way are connected continuously in an array form are sequentially joined. The orifice 6 and the main body plate The pressure chamber 19 in 22 and the ink supply path 12 communicate with each other. Then, the piezoelectric member 20 made of piezoelectric ceramic of the body plate 22.
Are formed into rectangular pipes that are divided into the pressure chambers 19 and are polarized in the radial direction. The individual electrodes 24 are formed on the inner surface of the through holes 23 that are voids that form the pressure chambers 19. A common electrode 26 is formed on the outer surface continuous to the inside of the gap 25 located between the pressure chambers 19.

In the ink jet printer head 18 having such a structure, the driving power is supplied to the electrodes 24 and 2.
When electricity is applied between 6 and 6, the piezoelectric member 20 of the main body plate 22 expands and contracts around the pressure chamber 19, so that ink (not shown) in the pressure chamber 19 is pressurized and ejected from the orifice 6.

An example of a method of manufacturing the body plate 22 of the ink jet printer head 18 as described above will be described in detail below. First, as in the piezoelectric member 14 illustrated as the first conventional example, injection molding, which is one of the molding processes, is performed, and as illustrated in FIG. 3A, a square through hole 23 and a rectangular void are formed. A rectangular parallelepiped piezoelectric member 28 in which the grooves 27 are alternately formed is formed. Here, since the piezoelectric member 28 is the base material of the piezoelectric member 20, the shape is different at this point. Therefore, as illustrated in FIG. 2B, the piezoelectric member 28 is bonded to the surface of the insulating substrate 21 on which the common electrode 26 is formed in advance on the lower surface where the groove 27 is opened, and illustrated in FIG. As described above, the upper portion of the piezoelectric member 28 is cut to the position of the concave groove 27 by polishing or dicing. Then, the piezoelectric member 20 divided by the gap 25 is formed for each through hole 23, so that as illustrated in FIG.
By forming the individual electrode 24 on the inner surface of the through hole 23 of the piezoelectric member 20 and the common electrode 26 on the outer surface thereof,
The common electrode 26 is integrated with the insulating substrate 21 on the insulating substrate 21 via a gap 25 or the like. Therefore, the piezoelectric member 20 thus formed is placed in silicon oil of 80 to 120 (° C.) and an electric field of 2 to 5 (kV / mm) is applied between the individual electrode 24 and the common electrode 26. As a result, the piezoelectric member 20 is polarized in the radial direction around the pressure chamber 19.

By doing so, in the ink jet printer head 18, the pressure chamber 19 is continuously provided in the single piezoelectric member 20 made of the injection-molded piezoelectric ceramic, so that the productivity of the piezoelectric member 20 is improved. The pressure chamber 19 is good, and the density of the pressure chamber 19 can be easily increased. Further, the common electrode 26 is formed in the entire circumferential direction of the pressure chamber 19 in which the individual electrode 24 is formed on the inner surface.
Is located, the piezoelectric member 20 has good driving efficiency and can contribute to power saving of the inkjet printer head 18. Further, in the ink jet printer head 18, since the piezoelectric member 20 is divided for each pressure chamber 19, these pressure chambers 19 are not affected by the operation of the adjacent pressure chambers 19 and their operation characteristics are It is extremely good and crosstalk is prevented.

The term "mold molding" as used in the present invention means either injection molding or extrusion molding, and does not include press working.

[0024]

As described above, according to the present invention, a common electrode is formed on the outer surface of a piezoelectric member which is formed into a tubular shape and is polarized in the radial direction, and an individual electrode is provided on the inner surface of the piezoelectric member. A pressure chamber in which the orifice and the ink supply path communicate with each other is formed in the positioned space, and the ink in the pressure chamber is pressurized by the contraction of the piezoelectric member in the radial direction due to the energization between the electrodes to eject an ink droplet from the orifice. In the inkjet printer head configured as described above, a piezoelectric member in which a large number of voids are continuous in an array is formed by molding of a piezoelectric ceramic, a common electrode is provided on the outer surface of this piezoelectric member, and the individual electrodes are shared on the inner surface of the void. Since the electrodes and the electrodes are provided alternately, a large number of pressure chambers can be continuously provided in one molded piezoelectric member, which improves the productivity of the piezoelectric member. It is easy to increase the density of the force chamber, and the common electrode can be positioned substantially in the entire circumferential direction of the pressure chamber having the individual electrodes formed on the inner surface, so that the driving efficiency of the piezoelectric member can be improved and the inkjet This has the effect of contributing to improved productivity of the printer head and power saving.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view.

FIG. 3 is a manufacturing process diagram showing a second embodiment.

FIG. 4 is an exploded perspective view.

FIG. 5 is a perspective view showing a conventional example.

[Explanation of symbols]

5,18 Inkjet printer head 6 Orifice 8,10,23,25,27 Air gap 9,19 Pressure chamber 12 Ink supply path 14,20,28 Piezoelectric member 15,24 Individual electrode 16,17,26 Common electrode

Claims (1)

[Claims] 1. A common electrode is formed on the outer surface of a piezoelectric member formed in a tubular shape and polarized in the radial direction, and an individual electrode is provided on the inner surface, and an orifice and ink are supplied in a space located inside the individual electrode of the piezoelectric member. An ink jet printer head that forms a pressure chamber communicating with a channel and pressurizes ink in the pressure chamber by the radial contraction of the piezoelectric member due to energization between the electrodes to eject ink droplets from the orifice. It is characterized by forming a piezoelectric member in which a large number of voids are continuous in an array by ceramic molding, providing a common electrode on the outer surface of this piezoelectric member, and alternately providing individual electrodes and common electrodes on the inner face of the void. Manufacturing method of inkjet printer head.