JPH0550596A - 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 providing non-piezoelectric members made of different materials on the center and the both ends of piezoelectric members is prepared, and the non-piezoelectric members provided at the both ends 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, non-piezoelectric members 21-23 made of different materials are provided on the center and the both ends of a pair of piezoelectric members 20. The drive plate 19 is bonded to the body plate 18 with the non-piezoelectric members 23 at the both ends, whereby pressure chambers 24 are formed. Furthermore, the non- piezoelectric members 21, 22 are made of conductive materials as electrodes. In this manner, since the drive plate 19 is bonded to the body plate 18 with the non-piezoelectric members 23, the non-piezoelectric members 21-23 are improved in material selectability and adhesion.

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. 2, the piezoelectric member 1 is a member that, when an electric field is applied at a right angle to a preset polarization direction, the piezoelectric member 1 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.

An ink jet printer head disclosed in Japanese Patent Laid-Open No. 3-49957 will be described below with reference to FIGS. 3 and 4 as an apparatus that solves such a problem. As shown in FIG. 3, the inkjet 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 blocking 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 Since the method of joining with 7 tends to be limited to adhesion, etc.,
Its productivity is decreasing.

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. In an ink jet printer head in which ink formed and held in a pressure chamber and held in a pressure chamber is pressed by a piezoelectric member that deforms in accordance with applied power and ejected from an orifice, piezoelectric elements located on each pressure chamber A non-piezoelectric member made of a different material is provided at the center and both ends of each pair of elastic members to provide a flat drive plate, and the drive plate is positioned at both ends of each pair of piezoelectric members. The non-piezoelectric member to be used was fixed to the main body plate.

According to a second aspect of the present invention, the non-piezoelectric member between the pair of piezoelectric members located on the pressure chamber is formed by one electrode, and both ends of the pair of piezoelectric members located on the pressure chamber are formed. The non-piezoelectric member of No. 1 was formed by the electrode and the non-piezoelectric member arranged in parallel.

[0013]

A non-piezoelectric member made of a different material is provided at the central portion and both end portions of each pair of piezoelectric members located on the pressure chamber to provide a flat drive plate. By fixing the non-piezoelectric members located at both ends of each pair of piezoelectric members to the main body plate, it is possible to obtain an inkjet printer head with good productivity.

[0014]

Embodiment An embodiment of the present invention will be described with reference to FIG.
In this inkjet printer head 16, a thick plate-shaped main body plate 1 in which a plurality of recesses in which an orifice 17 and an ink supply path (not shown) communicate with each other are arranged in an array.
8 and a thin plate-shaped drive plate 19 are integrally joined. Here, the drive plate 19 has a structure in which non-piezoelectric members 21 to 23 made of different materials are provided at the central portion and both end portions of each pair of piezoelectric members 20, and the non-piezoelectric members at both end portions are non-piezoelectric. A pressure chamber 24 is formed by adhering the drive plate 19 to the body plate 18 with a member 23. Here, the non-piezoelectric members 21 and 22 directly connected to the piezoelectric member 20 are electrodes made of a material having conductivity, and the non-piezoelectric member 23 located outside of these is insulated. It is made of a material that has high properties and is easily joined 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 24 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 25 supplied from the ink supply path is held in the pressure chamber 24, electricity is supplied between the predetermined non-piezoelectric members 21. As shown in the drawing, the pair of piezoelectric members 20 on the pressure chamber 24 undergo shear mode deformation, and the ink 25 is ejected from the orifice 17.

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

In the ink jet printer head 16, the non-piezoelectric member 23 of the drive plate 19 joined to the main 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-sealed at low temperature to the main body plate 18 can be used, and as the non-piezoelectric members 21 and 22 located on the pressure chamber 24 and acting as electrodes, polyacetal, polyethylene terephthalate, or the like is used. As described above, a resin material that can be easily fused at low temperature with the non-piezoelectric member 23 or the piezoelectric member 20 at both ends can be used. The adhesive used when the non-piezoelectric members 21 to 23 are bonded to the main body plate 18, the piezoelectric member 20, the non-piezoelectric members 22 and 23, etc., is an epoxy thermosetting adhesive or an optical thermosetting adhesive. A curable adhesive is used, and conductivity can be imparted to the non-piezoelectric members 21 and 22 by mixing a conductive filler into the resin material or the adhesive as described above.

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 23, so that the selectivity of the materials of the non-piezoelectric members 21 to 23 and the like is improved. It is expensive, and various joining methods such as adhesion and fusion can be carried out.

In the ink jet printer head 16 of the present embodiment, the pair of piezoelectric members 20 located on the pressure chamber 24 is polarized in the same direction, but for example, the pair of piezoelectric members 20 are polarized. It is also possible to polarize in different directions. In this case, in the inkjet printer head 16, since the pair of driven piezoelectric members 20 are energized in the same direction, the non-piezoelectric members located at both ends of the pair of piezoelectric members 20. It suffices to energize between 22. By doing so, it is not necessary to wire the non-piezoelectric member 21 located between the pair of piezoelectric members 20, so that the structure can be simplified and the productivity can be improved.

As a means for polarizing the pair of piezoelectric members 20 in different directions as described above, a pre-polarized flat plate-shaped piezoelectric member 20, non-piezoelectric members 21 to 23, etc. are sequentially laminated and driven. It can be implemented by cutting into the shape of the plate 19.

[0022]

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 the ink jet printer head, a non-piezoelectric member made of a different material is arranged at the center and both ends of each pair of piezoelectric members located on the pressure chamber, and a drive plate formed in a flat plate shape is provided. Since the non-piezoelectric members located at both ends of each pair of piezoelectric members of the plate are fixed to the main body plate, the material selectivity of the non-piezoelectric member is good, so The non-piezoelectric member located between them is formed with a single electrode, and the pair of piezoelectric members are polarized in different directions to simplify the wiring structure, or the non-piezoelectric members located at both ends of the pair of piezoelectric members are formed. The member can be formed of a material that is well bonded to the main body plate, and an effect such that an inkjet printer head with good productivity can be obtained.

According to a second aspect of the present invention, the non-piezoelectric member between the pair of piezoelectric members located on the pressure chamber is formed by one electrode, and both ends of the pair of piezoelectric members located on the pressure chamber are formed. By forming the non-piezoelectric member of the above in parallel with the electrode and the non-piezoelectric member, the pair of piezoelectric members are polarized in different directions to simplify the wiring structure or both ends of the pair of piezoelectric members. The non-piezoelectric member located at the position can be formed of a material that is well bonded to the main body plate, and an inkjet printer head with good productivity can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an operating principle of a piezoelectric member.

FIG. 3 is a vertical sectional front view showing a conventional example.

FIG. 4 is a process chart showing a method of manufacturing a drive plate.

[Explanation of symbols]

 16 Inkjet Printer Head 17 Orifice 18 Body Plate 19 Drive Plate 20 Piezoelectric Members 21,22 Electrodes 21-23 Non-Piezoelectric Member 24 Pressure Chamber 25 Ink

Claims (2)

[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 non-piezoelectric member made of a different material is provided at the center and both ends of each pair of the piezoelectric members respectively located on the pressure chambers, and a drive plate formed in a flat plate shape is provided. An ink jet printer head, wherein the non-piezoelectric members located at both ends of each pair of the piezoelectric members are fixed to the main body plate. 2. A non-piezoelectric member between a pair of piezoelectric members located on the pressure chamber is formed by a single electrode, and a non-piezoelectric property on both ends of the pair of piezoelectric members located on the pressure chamber. 2. The ink jet printer head according to claim 1, wherein the member is formed of an electrode and a non-piezoelectric member arranged in parallel.