JPH03197145A - Ink jet head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inkjet head used in an inkjet printer.

Conventional technology In recent years, inkjet printers have achieved high print quality.

They are rapidly becoming popular because they have many advantages over other printers, such as high resolution, quietness, and color printing.

A conventional inkjet head will be explained below.

FIG. 8 is a plan view showing the structure of a conventional inkjet head, and FIG. 9 is a plan view of the structure of a conventional inkjet head. It shows a sectional view taken along the line K-■'. 8 and 9, a plurality of ink jet ports 3 to 7 are provided between the substrate 1 and the diaphragm 2. Pressure chamber 8-1
2 and an ink supply section 13 are formed. Pressure chamber 8~
Piezoelectric elements 14 to 18 are bonded to the diaphragm 2 corresponding to 12. Reference numerals 1e and 20 are electrodes for applying an electric field to the piezoelectric element 16 from the control unit 21, and electrodes are similarly configured for the other piezoelectric elements.

The inkjet head as described above includes, for example, a substrate 1 and an ink supply section 13. Pressure chambers 8-12. Ink spout 3~
7 or the like is formed by etching or machining, and the diaphragm 2 is bonded to the substrate 1 by welding, adhesion, etc., and the piezoelectric elements 14 to 18 are bonded to the diaphragm 2. For example, when a drive signal is applied from the control unit 21 to the electrodes 19 and 2o of the piezoelectric element 16, the piezoelectric element 16 causes surface contraction (when the application is applied in the polarization direction of the piezoelectric element), and the piezoelectric element 16 and the diaphragm 2 of the bonded portion is displaced toward the pressure chamber, and the ink is pressurized by the pressure fluctuation in the pressure chamber 10, and ink droplets are ejected from the ejection port 5.

Problems to be Solved by the Invention However, in the above-mentioned conventional configuration, when the diaphragm is bonded to the substrate by welding or adhesive, the flow path may become clogged due to the flow of adhesive, and the substrate, diaphragm, and adhesive may become clogged. This has had the problem of lowering reliability and productivity because peeling may occur at the joint due to differences in the linear expansion coefficients of the materials.

The present invention solves the above-mentioned conventional problems, and aims to provide a high-performance, highly reliable, and inexpensive inkjet head.

Means for Solving the Problems In order to achieve this object, the inkjet head of the present invention has a structure in which a diaphragm having an electro-mechanical conversion function and a substrate are brought into close contact with each other by applying mechanical pressure.

Function: With this configuration, the substrate and the plate having an electro-mechanical conversion function are brought into close contact with each other by pressure, so defects caused by welding or adhesion can be prevented, performance and reliability can be improved, and costs can be reduced.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the structure of an inkjet head according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line 1--2' in FIG. In FIGS. 1 and 2, a plurality of ink jet ports 3 are provided between the substrate 1 and the diaphragm 2.
7, pressure chambers 8 to 12 and an ink supply section 13 communicating with each of the ejection ports are formed. The pressure chambers 8-1
Piezoelectric elements 14 to 18 are bonded to the diaphragm 2 corresponding to 2. Reference numerals 19 and 20 are electrodes for applying an electric field to the piezoelectric element 16 from the control unit 21, and electrodes are similarly configured in other piezoelectric elements, but they are not shown. The above is the same as the conventional example, but the substrate 1 and the diaphragm 2 are not joined by welding or adhesive, but are closely attached by pressure.

The substrate 1 is positioned by the convex portion of the head holder 22, and the diaphragm 2 is further positioned by the concave portion of the substrate 1. A pressure plate 23 is placed on the diaphragm 2, and is guided by a guide shaft of the head holding part 22, so that the diaphragm 2 is evenly pressed by a compression coil spring 24. By uniformly pressurizing the diaphragm 2, the ink in the flow path of the substrate 1 is sealed to prevent it from flowing into the contact surface between the diaphragm 2 and the substrate 1.

3 and 4 are a plan view and a sectional view taken along the line W-M' in FIG. 3, showing the structure of a second embodiment of the present invention.

In FIGS. 3 and 4, the plate having the function of an electro-mechanical conversion element consisting of a piezoelectric element and a diaphragm shown in the first embodiment is configured only with a piezoelectric element plate 26, and the piezoelectric element plate 25 A common electrode 26 is provided on the surface facing the pressure chamber, and electrodes 27 to 31 having the same size as the screaming chambers are provided on the surface opposite to the pressure chamber, corresponding to the pressure chambers 8 to 12. There is.

FIG. 5 shows a sectional view of a third embodiment of the present invention.
A Teflon sheet 32 is sandwiched between the plate 26 having the electro-mechanical transducer function shown in the second embodiment and the substrate 1, and the plate 26 is pressed by mechanical pressure.

FIG. 6 shows a sectional view of a fourth embodiment of the present invention.
The contact surfaces of the plate 25 having the electro-mechanical transducer function shown in the second embodiment and the substrate 1 are bonded to form an adhesive layer 33, and then they are pressed together by a mechanical pressure method.

FIG. 7 shows a cross-sectional view of a fifth embodiment of the present invention,
After applying a thin layer of silicone grease to the contact surface between the plate 25 having the electro-mechanical transducer function and the substrate 1 shown in the second embodiment to form a silicone grease layer 34, they were pressed together using a mechanical pressure method. be.

Effects of the Invention As described above, the present invention includes a substrate and a plate having an electro-mechanical conversion function, forming a plurality of pressure chambers having an ink supply section and an ink ejection port, and having the above-mentioned electro-mechanical conversion function. By mechanically applying pressure to bring the plate into close contact with the substrate, clogging of the ink flow path due to the flow of adhesive material that occurs when joining by welding or adhesion is prevented, and the joining is based on differences in linear expansion coefficients. This makes it possible to realize a highly reliable inkjet head that eliminates peeling of parts and is inexpensive.

In addition, in the case of foreign matter clogging the ink flow path, it was difficult to remove the foreign matter in the conventional example, but the present invention makes it possible to remove the foreign matter by disassembling the head.
This makes it possible to realize an inkjet head that is easy to assemble and is superior in terms of maintenance, inspection, and repair.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the structure of an inkjet head in a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line T in FIG. 1, and FIG. FIG. 4 is a plan view showing the structure of an inkjet head, FIG. 4 is a sectional view taken along the line IV-■', FIG.
The figure is a sectional view showing the structure of an inkjet head in a fourth embodiment of the present invention, FIG. 7 is a sectional view showing the structure of an inkjet head in a fifth embodiment of the invention, and FIG. 8 is a conventional inkjet head. FIG. 9 is a plan view showing the structure of the device, and FIG. 9 is a cross-sectional view thereof. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Plate having electro-mechanical conversion function, 3-7...Ink spout, 8-
12...Pressure chamber, 13...Ink supply unit, 24...Compression coil spring, 32...
・Teflon sheet, 33... Adhesive layer, 34...
...Silicon grease layer.

Claims (6)

[Claims] (1) A plurality of pressure chambers each having an ink supply section and an ink jetting port are formed using a substrate and a plate having an electro-mechanical conversion function, and mechanical pressure is applied between the substrate and the plate having an electro-mechanical conversion function. In addition, the inkjet head has a structure that allows close contact. (2) The inkjet head according to claim 1, wherein a piezoelectric material is used for the plate having an electro-mechanical conversion function. (3) The inkjet head according to claim 1, which uses a unimorph structure in which a metal plate, a glass plate, or a ceramic plate and a piezoelectric material are laminated to a plate having an electromechanical conversion function. (4) A sheet (for example, a resin sheet such as a Teflon sheet) of the same size as the substrate or the plate having an electromechanical conversion function is sandwiched between the substrate and the plate having an electromechanical conversion function, and the substrate and the plate having an electromechanical conversion function are The inkjet head according to claim 1, wherein a plate having a mechanical conversion function is pressed by mechanically applying pressure. (5) The inkjet head according to claim 1, wherein the contact surfaces of the substrate and the plate having an electro-mechanical conversion function are bonded together and then mechanically pressed into contact with each other. (6) The inkjet head according to claim 1, wherein a sealing material (for example, silicone grease) is applied to the contact surface of the substrate and the plate having an electro-mechanical conversion function, and then mechanical pressure is applied to the contact surface of the plate.