JP3261799B2 - Ink jet head and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In JP-A-63-247051, electrodes are provided on the walls of a plurality of ink flow paths separated by pressure partitions made of a piezoelectric material, and the walls are deformed by applying a voltage to the electrodes. There is disclosed an ink jet head for discharging ink. FIG. 3 shows the configuration of this ink jet head. Ink channels 32 to 32 are formed on a piezoelectric ceramic substrate 31 such as PZT by cutting or the like.
Is formed, a cover plate 33 is attached on the substrate 31 so as to cover the ink flow path 32, and an ejection port member 35 formed with ink ejection ports 34 to 34 is attached to an end surface thereof. The ink is filled in the ink flow path 32 from the ink supply port 36, and by selectively applying a voltage to the electrodes 37 to 37, the pressure partition walls separating the ink flow paths 32 are bent, and the ink is discharged from the ink discharge port 34. Ink is ejected.

[0003]

SUMMARY OF THE INVENTION In the above prior art,
Actually, since the end faces of the substrate 31 and the cover plate 33 have irregularities, even if the ejection port member 35 is adhered to the end face, it does not adhere sufficiently, and the ink leaks or the ink ejection direction changes. Therefore, the end face needs to be polished before the discharge port member 35 is attached. However, the polishing process takes a long time, and it is difficult to remove the polishing agent and polishing debris that have entered the substrate 31 side. In addition, chipping or cracking is likely to occur in the substrate 31 at the time of polishing, which causes a reduction in the yield of the head.

[0004] Further, there is a problem of adhesive strength of the discharge port member 35. Since ink is present on the surface of the discharge port 34, it must be cleaned. Usually, cleaning is often performed by mechanically rubbing with felt or the like. However, if the adhesive strength between the discharge port member 35 and the substrate 31 is insufficient, the two are separated from each other, which causes a reduction in long-term reliability. I was

Further, there is a problem in that the discharge port 34 is tapered. Considering the ink ejection efficiency, the ejection port 34
It is preferable that the outlet area is smaller than the area on the ink flow path 32 side in a tapered shape. However, the above-described taper processing is performed after the discharge port member 35 is bonded to the substrate 31 on which the ink flow path 32 is formed. Have difficulty.

Further, when the ejection port member 35 is bonded to the end face, it is difficult to align the ejection port 34 with the ink flow path 32.

The present invention can be easily manufactured with a simple structure,
It is another object of the present invention to provide a highly reliable inkjet head.

[0008]

An ink jet head according to the present invention has a plurality of ink flow paths separated by a pressure partition made of a piezoelectric material, and a head substrate having electrodes provided on the pressure partition, and an ink flow. A cover member adhered to the upper surface side of the head substrate on which the path is formed, and an ink jet head that deforms a pressure partition by applying a voltage to an electrode to discharge ink in an ink flow path from an ink discharge port. The ink flow path has a structure in which only the upper surface side of the head substrate is opened, and the bottom surface of the ink flow path formed in the head substrate is such that the area of the outlet of the ink discharge port is smaller than the area of the ink flow path side. Preferably, the ink flow path is provided by tapering from the bottom surface to the outlet in an open state.

Further, according to a method of manufacturing an ink jet head according to the present invention, an upper surface of a head substrate made of a piezoelectric material is provided.
Only the upper surface side is opened by the cutting process, a plurality of ink flow paths separated by the pressure partition are formed, and the bottom area of each ink flow path is irradiated with laser so that the area of the outlet is larger than the area of the ink flow path side. After forming a tapered ink ejection port that becomes smaller, an electrode for applying a voltage to the pressure partition is provided,
The cover member is bonded to the upper surface of the head substrate.

[0010]

[0011]

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a main part of an ink jet head according to the present invention. In FIG. 1, reference numeral 1 denotes a head substrate made of a piezoelectric material such as PZT. In the head substrate 1, a plurality of ink flow paths 2 to 2 are formed by cutting or the like. That is, the ink flow paths 2 and 2 are separated from each other by the pressure partition made of the piezoelectric material. An ink discharge port 3 is formed on the bottom of the ink flow path 2. The ink ejection port 3 is tapered so that the area on the outlet side is smaller than the area on the ink flow path 2 side. Reference numerals 4 to 4 denote electrodes for applying a voltage to the pressure barrier, and reference numerals 5 to 5 denote electric wires drawn from the electrodes 4.
A cover member (not shown) is adhered to the head substrate 1 so as to cover the ink flow path 2 to form an ink jet head, and print timing is applied to electrical wiring from a head driving means (not shown). Is supplied.

In the ink jet head having the above structure, the ink is filled in the ink flow path 2 and the electrodes 4 to 4 are supplied by signals from the head driving means in accordance with the printing timing.
4 is selectively applied with a voltage. When a voltage is applied to the electrode 4, the pressure partition wall on which the electrode is disposed bends, the ink pressure in the ink flow path 2 increases, and ink is ejected from the ink ejection port 3. Recording is performed in this manner.

Next, a method of manufacturing the above-described ink jet head will be described.

First, an ink flow path 2 is formed in the head substrate 1 by cutting or the like. Next, as shown in FIG.
Laser is emitted from the upper surface side of the ink flow path 2 to the bottom of the ink flow path 2 by the laser oscillator 21 to form the ink discharge port 3. As an example of a method of forming an ink ejection port using a laser, a wafer marker LM-
300, an oscillation wavelength of 1064 nm, and a repetition frequency of 1 kHz with respect to Fuji Ceramics PZT.
250 μm depth, 60 μm diameter on the laser beam incident side
m can be formed.

After the formation of the ink discharge ports 3, an electrode material such as Al or Ni is formed on the head substrate 1 by an oblique evaporation method or the like, and the electrode material on the upper surface of the pressure partition is separated to form the electrode 4. Adhere the cover member.

As described above, the head substrate shown in FIG. 1 is manufactured.

The laser is not limited to the YAG laser, but may be an ablation process using an excimer laser such as XeCl or KrF.

In the above embodiment, the entire head substrate is made of a piezoelectric material. However, at least the pressure partition wall may be made of a piezoelectric material.

[0021]

According to the ink jet head of the present invention, the ink discharge port is provided by tapering from the bottom surface of the ink flow path to the outlet in a state where the ink flow path formed in the head substrate is open. The process of polishing the bonding surface of the conventional ejection port member or aligning the ink ejection port with the ink flow path is not required, and the problem of peeling of the conventional ejection port member is eliminated, and long-term reliability can be secured. . Further, according to the method for manufacturing an ink jet head of the present invention, the ink flow path has a structure in which only the upper surface side of the substrate is opened, an electrode is formed on a pressure partition wall that forms the ink flow path, and a bottom surface of the ink flow path is formed. Since the ink discharge ports are directly formed, the head structure is simplified by using two members, a head substrate and a cover member, so that the manufacturing factory can be simplified and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a main part of an inkjet head according to the present invention.

FIG. 2 is an explanatory diagram for explaining a method of manufacturing an ink jet head according to the present invention.

FIG. 3 is an explanatory diagram showing a configuration of a conventional inkjet head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head board 2 Ink flow path 3 Ink ejection port 4 Electrode

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/135 B41J 2/16

Claims (2)

(57) [Claims] A plurality of ink flow paths separated by a pressure partition made of a piezoelectric material are formed, and an electrode is provided on the pressure partition.
And a cover member adhered to the upper surface side of the head substrate on which the ink flow path is formed, and deforming the pressure barrier by applying a voltage to the electrodes. an inkjet head that is not discharging the ink in the ink passages from the ink discharge port, said ink flow path and the only the upper surface of the head substrate is open structure, the ink discharge ports of the ink flow path side The ink flow path formed in the head substrate is provided on the bottom surface of the ink flow path such that the area of the outlet is smaller than the area by tapering from the bottom surface to the outlet in a state where the ink flow path is open. An ink jet head characterized by the following. 2. A head substrate made of a piezoelectric material,
Only the top side is opened by cutting, and the pressure
Forming a plurality of separated ink flow paths;
By irradiating the laser to the bottom of the path,
Tapered ink ejection port with smaller exit area
After forming the electrodes, electrodes for applying a voltage to the pressure bulkhead are provided.
To adhere a cover member to the top surface of the head substrate.
A method for manufacturing an ink jet head, which is characterized in that: