JPH02162050A - Ink jet head - Google Patents

Abstract

PURPOSE:To obtain a high grade ink jet head of a multi-nozzle type by composing the ink jet head of a nozzle forming member and a pressure generating member as a main constituent, and aligning and arranging plural ink jet elements that are independently processed and produced. CONSTITUTION:A nozzle 21 formed on the nozzle forming member 20 and the pressure generating member 32 are oppositely arranged with a fine gap 24, and ink is charged in an ink pool 31, whereby the pressure generating member 32 is dipped with the ink. The pressure generating member 32 is laminated with a piezoelectric element 33 contracting in a direction perpendicular to an electric field owing to voltage application and a deformation promoting member 32, and is deformed in the direction of an arrow 35 by the control of voltage application to the piezoelectric element 33. This deformation changes pressure to the ink in the fine gap 24 between the nozzle forming member 20 and the pressure generating member, thereby jetting an ink drop from the nozzle 21.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an inkjet head that ejects ink droplets from a nozzle by deforming a pressure generating member and changing the pressure of ink existing in a gap with a nozzle forming member. Regarding the structure of

[Conventional technology]

A nozzle forming member is provided, and a pressure generating member is immersed in ink and disposed facing the nozzle formed in the nozzle forming member with a minute gap therebetween, and the pressure generating member is deformed by applying a voltage to form the nozzle forming member. An inkjet head that ejects ink droplets from a nozzle by changing the pressure of ink existing in a gap is disclosed in Japanese Patent Publication No. 60-8953, for example. Due to the almost vertical deformation and the short ink flow path of the nozzle, it has excellent ink droplet ejection efficiency and ejection stability, and is not affected by air bubbles or dust mixed into the ink. It operates normally, and furthermore, because the pressure generating member has a cantilevered or double-sided beam structure, the electromechanical conversion efficiency is high, and the required deformation of the pressure generating member can be achieved with a low voltage. has.

[Problem to be solved by the invention]

Conventionally, in this type of inkjet head,
It has been found that the gap between the nozzle forming member and the pressure generating member has a large effect on the inkjet characteristics, and even if an attempt is made to realize a multi-nozzle type inkjet head, it is difficult to match the inkjet characteristics of each nozzle due to processing and manufacturing issues. It was difficult to do so, and from the viewpoint of yield, it was said that there was a limit to the ability to use multiple nozzles, which hindered the development of printing devices using this type of inkjet head.

An object of the present invention is to solve this technical problem and provide a high-level multi-nozzle type inkjet head that could not be realized in the past.

[Means to solve the problem]

The inkjet head of the present invention includes a nozzle forming member and a pressure generating member immersed in ink and disposed facing the nozzle formed in the nozzle forming member with a minute gap, and the pressure generating member is activated by applying a voltage. An inkjet head that ejects ink droplets from a nozzle by deforming the ink and changing the pressure of the ink existing in the gap between the nozzle forming member and the nozzle forming member. It is characterized by having multiple processed and manufactured inkjet elements aligned and arranged to form a multi-nozzle.

[Effect]

According to the above configuration of the present invention, inkjet elements having the same gap between the nozzle forming member and the pressure generating member, that is, the inkjet characteristics, are selected from among the inkjet elements that are processed and manufactured separately, and are arranged in an aligned manner. As a result, a multi-nozzle type inkjet head can be realized.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

FIG. 3 is a perspective view for explaining an embodiment of a recording apparatus equipped with an inkjet head according to the present invention.

The recording medium 1 is wound around the platen 4 by the pressure of the feed rollers 2 and 3, and is conveyed in the direction of the arrow 5 as recording progresses. An inkjet head 9 having a plurality of nozzles is mounted on a carriage 8 that is guided by guide shafts 6 and 7 and movable in a direction parallel to the axis of the platen 4. The inkjet head 9 has a plurality of nozzles. An ink image is formed on a recording medium 1 by ejecting ink droplets from a nozzle.

FIG. 1 shows an embodiment of an inkjet head according to the present invention. Nozzle 2 formed on nozzle forming member 20
The inkjet element 25 is formed by laminating and bonding the pressure generating member 1 and the pressure generating member 22 with the intermediate member 23 interposed so that they are arranged facing each other with a small gap 24 maintained.
27 are inserted through the guide shafts 28 and 29, and are aligned and arranged by being pressed and joined by a cover 30, thereby forming a multi-nozzle type inkjet head.

Further, the ink reservoir 31 is filled with ink, and the pressure generating member 22 is immersed in the ink. The pressure generating member 22 has a laminated structure of a piezoelectric element 33 that contracts in a direction perpendicular to the electric field when voltage is applied, and a deformation assisting member 34. By controlling the voltage applied to the piezoelectric element 33,
Deformation occurs in the direction of arrow 35. Due to this deformation, the pressure of the ink existing in the minute gap 24 with the nozzle forming member 20 changes, and ink droplets (not shown) are ejected from the nozzle 21.

FIGS. 2(a) and 2(b) show another embodiment of the method for manufacturing an inkjet element according to the present invention. In this embodiment, first, the original member 50 of the nozzle forming member/deformation assisting member and the piezoelectric element 33 are joined, and then the original member 50 and the piezoelectric element 33 are divided in a direction perpendicular to the joining surface 51, and the original member of the inkjet element is 52 (Fig. 2 (a)
)). Next, using well-known photolithography technology, the minute gap 24 and guide holes 26 and 27 are formed from the dividing surface 53 side of the inkjet element original member 52, the ink supply path 54 is formed from the piezoelectric element 33 side, and the ink supply path 54 is formed from the opposite side. The nozzles 21 are each formed from the inkjet element 25.
(Fig. 2(b)).

In this inkjet element processing/manufacturing method, the gap 24 between the nozzle forming member 20 and the pressure generating member 22 is
Since the main dimensions of the inkjet element 25 are formed using photolithography technology, it is processed with very high precision and the inkjet characteristics are easily matched, so the manufacturing yield of the inkjet element 25 is high. can be processed, which greatly reduces manufacturing costs.

Furthermore, in photolithography technology, it is also possible to employ anisotropic etching by selecting the thick member 50 or the etching device. In addition to becoming more uniform, the degree of freedom in design increases because there are no restrictions on the shape that can be processed due to the occurrence of so-called side etching.

In addition, in these embodiments of inkjet elements, inkjet elements each having one nozzle are taken as an example, but the number of nozzles per inkjet element is not limited as long as the inkjet characteristics are uniform. It is clear from the gist of

〔Effect of the invention〕

As described above, according to the present invention, a plurality of inkjet elements, which are mainly composed of a nozzle forming member and a pressure generating member, are aligned and arranged to form an inkjet head with multiple nozzles. From among the processed and manufactured inkjet elements, inkjet elements with the same gap between the nozzle forming member and the pressure generating member, that is, the inkjet characteristics, are selected and arranged, which reduces the yield rate during processing and manufacturing. It is possible to eliminate the limit on the level of multi-nozzle technology that had arisen from the point of view,
As a result, it becomes possible to improve the performance of printing devices using this type of inkjet head, which was previously considered impossible. Further, the inkjet head of the present invention can realize inkjet heads with various numbers of nozzles simply by changing the number of aligned inkjet elements, so standardization of the inkjet elements is advantageous in terms of manufacturing costs.

33...Piezoelectric element 34...Deformation assisting member 5
0...Additional member 52...Inkjet element original member or more

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of an inkjet head according to the present invention, FIGS. 2(a) and (b) are diagrams depicting another embodiment of the method for manufacturing an inkjet element according to the present invention, and FIG. FIG. 1 is a perspective view for explaining an embodiment of a recording apparatus equipped with an inkjet head according to the present invention. Applicant: Seiko Epson Co., Ltd. Agent: Patent Attorney Kizobe Suzuki and 1 other person 9... Inkjet head 20... Nozzle forming member 21... Nozzle 22...
・Pressure generating member 24... Gap 25... Inkjet element

Claims (1)

[Scope of Claims] A nozzle forming member; a pressure generating member immersed in ink and disposed facing the nozzle formed in the nozzle forming member with a minute gap; An inkjet head that ejects ink droplets from the nozzle by changing the pressure of ink existing in a gap between the nozzle forming member and the nozzle forming member, the main elements being the nozzle forming member and the pressure generating member. An inkjet head characterized in that a plurality of separately processed and manufactured inkjet elements are aligned and arranged to form a multi-nozzle.