JPH08281946A - Ink jet device and manufacture thereof - Google Patents

Abstract

PURPOSE: To execute stable ink ejection by a constitution wherein an inclination section which is made of a member different from a member forming an ink chamber and is gradually inclined such that the size of an opening of an ink chamber becomes smaller toward the outside, thereby eliminating a difference in level between the ink chamber and a nozzle. CONSTITUTION: In a manufacture process of an ink jet device 1, a groove to be an ink chamber 4 is firstly formed on a piezoelectric ceramic plate 2 to which a polarization processing is applied beforehand. Next, the groove to be the ink chamber 4 is filled with a resin member 80. The resin member 80 is processed by an exima laser beam toward a position, to which a nozzle plate 60 is provided, such that the shape of the groove of the ink chamber 4 gradually becomes close to that of a nozzle 50 of the nozzle plate 60. After that, the nozzle plate 60 on which the nozzle 50 is formed and a manifold are bonded to the piezoelectric ceramic plate 2 having the ink chamber 2 by an adhesive. Thereby, a difference in level between the ink chamber 4 and nozzle 50 can be shortened and the turbulence of ink ejection due to the bubble can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet device.

[0002]

2. Description of the Related Art Piezoelectric ink jet devices have been proposed in recent years. This inkjet device has a plurality of ink chambers. The volume of this ink chamber is changed by the dimensional displacement of the piezoelectric actuator. When the volume of the ink chamber decreases, the ink in the ink chamber is ejected, and when the volume increases, the ink is introduced into the ink chamber. Then, a large number of such ink chambers are arranged close to each other to form an inkjet device, and ink is ejected from the ink chambers at predetermined positions, whereby desired characters and images can be formed.

Regarding such an ink jet device,
This will be specifically described with reference to a perspective view of the inkjet device 1 shown in FIG. 8 and a partial sectional view of the inkjet device 1 shown in FIG. 9.

By joining the piezoelectric ceramic plate 2 having a plurality of side walls 5 and polarized in the direction of the arrow 28 and the lid 6, a large number of parallels having a space therebetween in the lateral direction in FIG. The ink chamber 4 is configured. The ink chamber 4 has a rectangular cross section that is long and narrow, and the side wall 5 extends over the entire length of the ink chamber 4. As the side wall 5 is deformed, the volume of the ink chamber 4 changes and the ink pressure in the ink chamber 4 changes. A drive electrode 7 for applying a drive electric field is formed in a region of the lower half (or upper half) of the surface of the side wall 5, and the surface of the drive electrode 7 insulates the ink from the drive electrode 7. Insulation treatment is applied.
A nozzle plate 60 having a nozzle 50 communicating with one end of each ink chamber 4 is fixed to one end of the piezoelectric ceramic plate 2 and the lid 6 with an adhesive 70.

In the ink jet device 1, as shown in FIG. 9, when, for example, the ink chamber 4B is selected in accordance with predetermined print data, a drive unit (not shown) is provided between the drive electrodes 7C and 7D and the drive electrodes 7E and 7F. A driving electric field 10 is applied to the. At this time, since the driving electric field direction and the polarization direction are orthogonal to each other, the side walls 5B and 5C are deformed in a V shape toward the outside of the ink chamber 4B due to the piezoelectric thickness sliding effect. At this time, ink is supplied into the ink chamber 4B.
After that, when the application of the driving electric field 10 is cut off, the side walls 5B and 5C return to their original positions. Due to this deformation, the ink pressure in the ink chamber 4B becomes large, and ink droplets are ejected from the nozzle 50 corresponding to the ink chamber 4B.

As a conventional method of manufacturing the nozzle 50, for example, a method disclosed in Japanese Patent Laid-Open No. 3-101960 is known.

As shown in FIG. 10, the laser beam 64 oscillated by the excimer laser device 61 is used as the optical lens system 6
The mask 62 made of copper is irradiated via 6 Mask 62
An enlarged similar pattern of a predetermined nozzle pattern of the nozzle plate 60 is formed on the. The laser beam 64 passing through the mask 62 is further focused on the plate 59 by the lens 67 to form the nozzle 50 having a predetermined shape at a predetermined position on the plate 59. In this way, the nozzle plate 60 is formed by forming a large number of nozzles 50 having a predetermined shape at predetermined positions on the plate 59.
For the plate 59, a material that does not deteriorate with respect to the solvent in the ink component, for example, a polyimide resin is used.

Thereafter, as shown in FIG. 8, the nozzle plate 60 is fixed to the piezoelectric ceramic plate 2 and one end surface of the lid 6 with an adhesive 70.

[0009]

In the conventional ink jet device as described above, a step is formed at the joint between the ink chamber 4 and the nozzle 50 formed in the nozzle plate 60, and the bubble is trapped in the step, which is stable. There is a problem that it hinders ink ejection.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an ink jet device which can eliminate the step between the nozzle and the ink chamber and can stably eject ink, and a manufacturing method thereof. And

[0011]

In order to achieve this object, according to a first aspect of the present invention, in an ink jet device having an ink chamber communicating with a nozzle for ejecting ink, a member different from a member constituting the ink chamber is provided. The member is provided with an inclined portion that is gradually inclined so that the size of the opening of the ink chamber is reduced.

According to another aspect of the present invention, the nozzle is formed at the tip of the ink chamber by the inclined portion.

According to a third aspect of the present invention, in a method of manufacturing an ink jet device having an ink chamber that communicates with a nozzle for ejecting ink, a step of forming a groove to be an ink chamber and a step of filling a filler in the groove. A step of etching the filling material to process an inclined portion having a gradually inclined shape so that the size of the opening of the ink chamber becomes small; and covering the groove having the inclined portion with the inclined portion. And a step of forming an ink chamber.

According to a fourth aspect of the present invention, there is provided a method of manufacturing an ink jet device, characterized in that a nozzle is formed at the tip of the ink chamber by the inclined portion.

According to a fifth aspect of the method of manufacturing an ink jet device, the filling material is a material processed by an excimer laser beam.

[0016]

In the ink jet apparatus of the present invention having the above structure, the ink chamber is gradually inclined toward the nozzle side due to the inclined portion of the member forming the ink chamber and the separate member, and the step difference between the ink chamber and the nozzle is formed. Almost disappeared, and bubble trapping at the step is eliminated.

Further, in the method for manufacturing an ink jet device of the present invention, first, a groove to be an ink chamber is formed, and a filling material is filled in the groove. Next, the filling material is etched to form an inclined portion having a gradually inclined shape so that the size of the opening of the ink chamber is reduced, and the groove is covered to form the ink chamber. Due to the inclined portion, the ink chamber is gradually inclined toward the nozzle side, the step between the ink chamber and the nozzle is almost eliminated, and air bubbles are not trapped at the step.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. For the sake of convenience, the same parts as in the conventional example and the equivalent parts will be described with the same reference numerals.

FIG. 1 shows a piezoelectric ceramic plate 2 which has been subjected to a polarization treatment, in which a groove to be an ink chamber 4 is processed. In this embodiment, this groove is processed by a dicer, and its shape is 400 μm in length and 100 in width.
It has a long and narrow rectangular cross section of μm. The size of the cross section of the groove (ink chamber) and the aspect ratio are not limited to those in the present embodiment, but are values that depend on the physical properties of the ink, the ink ejection speed, and the like. And such a value was set from the injection characteristics.

Next, as shown in FIG. 2, a resin member 80 is filled in the groove which becomes the ink chamber 4. The resin member 80 has a good laser processability with an excimer laser beam, and since it is in direct contact with the ink, a member resistant to the ink is preferable.
In this embodiment, the ink chamber 4 is filled with an epoxy resin. Care was taken in filling so that air bubbles were not entrapped. In addition, stoppers (not shown) were provided on both end faces of the ink chamber 4 so that they would not flow out to both end faces when the epoxy resin was filled.

Here, in this embodiment, the ink chamber 4
Although the resin member is used for filling the above for the above reason, it is not limited to the resin member and may be filled with glass or the like and processed into a shape described later by etching or the like.

Next, the resin member 8 filled in the ink chamber 4
0 toward the direction in which the nozzle plate 60 is provided so that the groove shape of the ink chamber 4 gradually approaches the shape of the nozzle 50 provided in the nozzle plate 60.
Processing is performed by the excimer laser beam 64. In this embodiment, an excimer laser device using a KrF excimer laser beam is used, and the excimer laser beam 64 is irradiated from the manifold hold side of the ink chamber 4 under a laser condition of energy density of 1 J / cm ² , and the nozzle is kept at a constant speed. The side was scanned, and the speed was changed as it approached the nozzle side for processing. By such processing, the cross-sectional shape of the ink chamber 4 on the nozzle side as shown in FIG. 4 was gradually reduced and a shape approaching the nozzle 50 was obtained.

The piezoelectric ceramic plate 2 having the ink chambers 4 thus obtained is joined to the nozzle plate 60 having the nozzles 50 and the manifold 90 by using an adhesive (not shown). An inkjet head having an ink chamber 4 sectional shape as shown in FIG. 5 was obtained. Here, the nozzle 50 was formed on a resin plate by an excimer laser beam as in the conventional example. In this example, a polysulfone resin having durability was used for the ink.

The head thus obtained, which has a very small step between the ink chamber 4 and the nozzle 50, was evaluated for ejection. As a result, it was found that there was no disturbance in ink ejection due to bubbles, and very stable ejection was obtained. It was confirmed to last.

In this embodiment, as shown in FIG.
The ink chamber 4 was formed in the piezoelectric ceramic substrate 2, and the lid 6 was further covered to form the ink chamber 4. However, as shown in FIG. 6, two piezoelectric ceramic substrates 2 were used, each groove was processed, and each of them was processed. An ink chamber may be formed by filling the groove with a resin member as in this embodiment, performing laser processing in the same manner, and then abutting and joining the groove portions of the respective ceramic substrates 2.

Further, as shown in FIG. 7, a head having a desired nozzle shape for the final shape of the ink chamber, that is, a head in which the nozzle plate 60 is not separately joined, is produced by the resin member with which the ink chamber 4 is filled. The injection was evaluated. As a result, it was confirmed that stable ejection can be performed similarly to the head of this embodiment in which the nozzle plate 60 is separately joined.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the present embodiment, the present invention is used for an inkjet head of a system that ejects ink by deformation of a piezoelectric element, but the present invention may be used for a known thermal jet inkjet head.

[0028]

As is apparent from the above description, according to the present invention, since the ink chamber is gradually brought closer to the nozzle shape toward the nozzle side by the inclined portion, the step difference between the nozzle and the ink chamber is formed. There are very few bubbles, and bubbles do not remain on the step. Therefore, stable injection can be maintained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a manufacturing process of an inkjet device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of the inkjet device according to the embodiment.

FIG. 3 is an explanatory diagram showing a manufacturing process of the inkjet device of the embodiment.

FIG. 4 is a cross-sectional view showing a manufacturing process of the inkjet device according to the embodiment.

FIG. 5 is a cross-sectional view showing a part of the ink jet device of the above embodiment.

FIG. 6 is a cross-sectional view showing a part of an inkjet device according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a part of an inkjet device according to still another embodiment of the present invention.

FIG. 8 is a perspective view showing a conventional inkjet device.

FIG. 9 is a cross-sectional view showing a conventional inkjet device.

FIG. 10 is an explanatory diagram showing a manufacturing process of a conventional nozzle plate.

[Explanation of symbols]

 1 Inkjet Device 2 Piezoelectric Ceramics Plate 4 Ink Chamber 6 Lid 50 Nozzle 60 Nozzle Plate 64 Excimer Laser Beam 80 Resin Member

Claims (5)

[Claims] 1. An ink jet device having an ink chamber communicating with a nozzle for ejecting ink, wherein the member constituting the ink chamber and a member separate from each other are gradually inclined so that the size of the opening of the ink chamber is reduced. An inkjet device comprising an inclined portion having the above shape. 2. The ink jet apparatus according to claim 1, wherein a nozzle is formed at the tip of the ink chamber by the inclined portion. 3. A method of manufacturing an ink jet device having an ink chamber communicating with a nozzle for ejecting ink, forming a groove to be an ink chamber, filling the groove with a filler, A step of etching the filling material to process a sloping portion having a gradually sloping shape so that the size of the opening of the ink chamber becomes small; and covering the groove having the sloping portion to cover the ink chamber. A method for manufacturing an inkjet device, which comprises a step of forming. 4. The method according to claim 3, wherein a nozzle is formed at the tip of the ink chamber by the inclined portion. 5. The method according to claim 3, wherein the filling material is a material processed by an excimer laser beam.