JPH0550597A - Ink jet printer head - Google Patents

Abstract

PURPOSE:To simplify a structure of a drive plate in an ink jet printer head having a structure in which a drive plate provided with piezoelectric members is bonded to a body plate provided with pressure chambers and orifices to realize a small-size and light-weight device, an improvement of productivity, and the like. CONSTITUTION:A drive plate 19 is formed by disposing a piezoelectric member 20 and a non-piezoelectric member 21 on a pressure chamber 26.

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. 3, 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 energization 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. 4 and 5. As shown in FIG. 4, the ink jet printer head 3 includes a thin plate-shaped drive plate 6 in which electrodes 4 composed of thermistors and piezoelectric ceramics 5 as 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 recess 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 ceramic material 10 that forms the piezoelectric ceramic 5 and a barium titanate-based ceramic material 11 that forms the electrode 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, the 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 that of the drive plate 6 is formed by cutting this at a right angle to the stacking direction. Here, in this ceramic plate 13, since the polarization direction of the piezoelectric ceramic 5 is random at this stage, as shown in FIG.
Plate electrodes 14 and 15 are attached to the cut surface of, 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 polarized well.

[0008]

In the ink jet printer head 3 disclosed in the above publication, the electrodes 4 are located at both ends of the pair of piezoelectric ceramics 5 located on the pressure chambers 9. Ceramic 5 and electrode 4
The increase in the number of products hinders the reduction in size and weight and the improvement in productivity.

In the ink jet printer head 3, the electrodes 4 of the driving plate 6 are made of piezoelectric ceramics 5.
The material must be a thermistor material in order to realize the above polarization, and the selectivity of the material is low, and the bonding method with the main body plate 7 tends to be limited to adhesion or the like. further,
In this inkjet printer head 3, the electrode 4 of the drive plate 6 needs to be thickly formed to have a thickness of about 100 (μm) in order to achieve good bonding with the main body plate 7. However, the electrode 4 having such a thickness is sputtered. It is difficult to form by thin film technology such as or vapor deposition.

The present invention provides an ink jet printer head which is easy to reduce in size and weight and to improve productivity.

[0011]

A flat plate is provided in which a main body plate in which a plurality of recesses in which an orifice and an ink supply path communicate with each other are connected in an array is provided, and piezoelectric members and non-piezoelectric members are alternately provided. A drive plate formed in a shape is provided, and one piezoelectric member and one non-piezoelectric member are respectively positioned on one concave portion by joining the drive plate and the main body plate to form a pressure chamber.

[0012]

By arranging one piezoelectric member and one non-piezoelectric member on one pressure chamber, it is possible to obtain an ink jet printer head which is small in size and easy in productivity.

[0013]

Embodiments of the present invention will be described with reference to FIGS. 1 and 2. First, as illustrated in FIG. 1, in the inkjet printer head 16, a thick plate-shaped main plate 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. 18 and a thin plate-shaped drive plate 19 are integrally joined. Here, the drive plate 19 is formed in a flat plate shape by alternately providing piezoelectric members 20 and non-piezoelectric members 21 having a length of about 2 to 3 in the continuous installation direction, and the piezoelectric plate 20 is formed on the surface thereof. Thin film individual electrodes 22 are individually provided on the elastic member 20, and a thin film common electrode 23 is uniformly provided on the back surface. In the inkjet printer head 16, the drive plate 19 is provided with the common electrode 23 so that one piezoelectric member 20 and one non-piezoelectric member 21 are located on one recess of the main body plate 18. The pressure chamber 24 is formed by being bonded to the main body plate 18.

In the ink jet printer head 16 having such a structure, the piezoelectric member 20 needs to be sealed without being fixed to the main body plate 18 in the direction of the front and back surfaces in the figure, but this has elasticity. It can be realized by using an adhesive agent, a film or the like.

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 electrodes 22 and 23. As shown, the piezoelectric member 20 on the pressure chamber 24 undergoes shear mode deformation and moves together with the non-piezoelectric member 21, so that the ink 25 is ejected from the orifice 17.

That is, in the ink jet printer head 16, the piezoelectric member 20 is provided for one pressure chamber 24.
Since only one non-piezoelectric member 21 and one non-piezoelectric member 21 correspond to each other and the number thereof is extremely small, the structure of the drive plate 19 is simple, and it is possible to contribute to reduction in size and weight and improvement in productivity. Furthermore, this inkjet printer head 16
In this case, since the non-piezoelectric member 21 is forcibly deformed by the shear mode deformation of the piezoelectric member 20, the material selection of the non-piezoelectric member 21 and the length in the connecting direction of the members 20 and 21 are different. The protrusion characteristic of the ink 25 can be changed by the ratio or the like.

In the ink jet printer head 16, the piezoelectric members 20 in the drive plate 19 are polarized in the continuous arrangement direction which is horizontal in the figure, and each piezoelectric member 2 is polarized.
Since 0 will be energized in the same vertical direction,
For example, one constant voltage power supply is connected to the common electrode 23 and wiring is performed so that the individual electrodes 22 are grounded pair by pair via a switching element. Further, in this inkjet printer head 16, only the shear mode deformation occurs in the driven piezoelectric member 20, so that the occurrence of crosstalk is prevented.

In the ink jet printer head 16, only one wiring needs to be formed on the common electrode 23 that is electrically connected to all the piezoelectric members 20, so that the wiring structure is extremely simple, and the size and weight can be further reduced and the production can be improved. It is possible to contribute to improving the property.

Further, in the ink jet printer head 16, as the non-piezoelectric member 21 in the drive plate 19, a resin material such as polyacetal or polyethylene terephthalate which is easily heat-bonded to the piezoelectric member 20 at low temperature is used. It is possible. In addition, such a non-piezoelectric member 2
As an adhesive for bonding 1 to the piezoelectric member 20,
An epoxy thermosetting adhesive or a photo-curing adhesive is used.

Further, in the ink jet printer head 16, since it is not necessary to manufacture the electrodes 22 and 23 and the non-piezoelectric member 21 with the thermistor, the selection of the material and the degree of freedom of the manufacturing method are very good. .. In particular, since the electrodes 22 and 23 are only formed on the front and back surfaces of the flat drive plate 19, they can be easily formed by a thin film technique such as sputtering or vapor deposition, and their productivity is extremely good.

Further, in this ink jet printer head 16, the piezoelectric member 20 is formed in a slender shape in the continuous direction in order to ensure good driving efficiency, and the electrodes 22 and 23 are formed on the elongated front and back surfaces thereof. Therefore, the conductive area between each of the electrodes 22, 23 and the piezoelectric member 20 is large, and the piezoelectric member 20 is energized in the lateral direction to reduce the electrode resistance of the piezoelectric member 20 to reduce power consumption. It is possible to reduce.

As a method of manufacturing the drive plate 19 as described above, a plate-shaped piezoelectric member 20 and a non-piezoelectric member 21 which are polarized in advance are sequentially laminated and cut into the shape of the drive plate 19. It is feasible. The electrodes 22, 2 of the drive plate 19 thus manufactured are
3 is to manufacture the piezoelectric member 20 by plating or sputtering before stacking the members 20 to 21,
After stacking, it is possible to manufacture by photolithography or the like.

In the ink jet printer head 16 of this embodiment, each piezoelectric member 20 is polarized in the direction of continuous arrangement to provide the electrodes 22 and 23 on the front and back surfaces of the drive plate 19, as shown in FIG. , The piezoelectric member 27 in the drive plate 26 is polarized at right angles to the continuous direction, and an electrode 29 is provided between the piezoelectric member 27 and the non-piezoelectric member 28. Can also be implemented.

[0024]

As described above, the present invention provides 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 piezoelectric member and a non-piezoelectric member are alternated. By providing a drive plate formed in a flat plate shape provided in, and by joining the drive plate and the main body plate to position one piezoelectric member and one non-piezoelectric member respectively on one recess, The number of piezoelectric members and non-piezoelectric members can be reduced to simplify the structure of the drive plate, and the selection of materials for the non-piezoelectric members and electrodes and the degree of freedom in the manufacturing method are good, so the size is small. This has effects such as being able to obtain an inkjet printer head that can be easily reduced in weight and improved in productivity.

[Brief description of drawings]

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

FIG. 2 is a vertical sectional front view showing a modified example.

FIG. 3 is a schematic diagram showing an operating principle of a piezoelectric member.

FIG. 4 is a vertical sectional front view showing a conventional example.

FIG. 5 is a process drawing showing a method of manufacturing a drive plate.

[Explanation of symbols]

16, 30 Inkjet printer head 17 Orifice 18 Main body plate 19, 26 Drive plate 20, 27 Piezoelectric member 21, 28 Non-piezoelectric member 22, 23, 29 Electrode 24 Pressure chamber 26 Ink

Claims (1)

[Claims] 1. A main body plate in which a plurality of recesses, each communicating with an orifice and an ink supply path, are continuously arranged in an array, and a piezoelectric member and a non-piezoelectric member are alternately provided to form a flat plate shape. A drive plate is provided, and a pressure chamber is formed by joining the drive plate and the main body plate to position one piezoelectric member and one non-piezoelectric member respectively on the one recess. Inkjet printer head.