JPH07195687A - Ink jet head - Google Patents

Abstract

PURPOSE:To obtain an ink jet head of a high yield by providing a first substrate with a plurality of ink chambers, a second substrate with nozzles corresponding to the ink chambers and means for impressing a pressure into each ink chamber, and covering the ink chambers with the second substrate having a common ink feed path. CONSTITUTION:Conventionally, a common feed path is formed generally at a central part of a first substrate. Therefore, the first substrate is easy to decrease in strength. In this ink jet head, a common feed path 24 is formed in a second substrate 18. The common feed path 24 is located generally at a central part of two rows of ink chambers 12 of a first substrate 14 and partly overlapped with the ink chambers 12. The overlapped part is approximately 5mum long and therefore functions enough to feed ink. The overlapped part has an area of approximately 2500mum<2>. The first substrate 14 has only the ink chambers 12, while the second substrate 18 has nozzles 16 and the common feed path 24. Accordingly, the substrates are not feared to break, with a yield improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet head used in an apparatus such as a printer to which an inkjet recording system is applied.

The ink jet recording system for recording by ejecting ink droplets has a simple structure and is easy to colorize.
It has features such as low noise and is expected as the mainstream of future recording methods.

[0003]

2. Description of the Related Art Conventionally, a plurality of ink chambers are formed as an ink jet head for ejecting ink from nozzles by applying pressure to the ink chambers communicating with the nozzles.
It is known to provide a substrate, a second substrate having nozzles formed at positions corresponding to the respective ink chambers, and a pressure applying means for applying a pressure to the ink chamber via the first substrate.

The first and second substrates are attached so that the ink chambers are covered by the second substrate, and a common supply path for supplying ink to each ink chamber is lined up in the ink chambers on the first substrate. Has been formed.

[0005]

In the conventional ink jet head described above, since the ink chamber and the common supply passage are formed on the same substrate, the area of the thin portion of this substrate becomes large, There is a problem that the substrate is easily broken during the manufacturing operation and the manufacturing yield of the inkjet head is low.

Therefore, an object of the present invention is to provide an ink jet head having a high manufacturing yield.

[0007]

According to the present invention, there is provided an ink jet head for ejecting ink from a nozzle by applying pressure to the ink chamber communicating with the nozzle, wherein a plurality of ink chambers are formed. A first substrate, a second substrate having nozzles formed at positions corresponding to the respective ink chambers, and a pressure applying unit for applying a pressure to the ink chamber via the first substrate. The second substrate is attached so that the ink chamber is covered by the second substrate, and a common supply path for supplying ink to each of the ink chambers is further formed on the second substrate. Will be provided.

[0008]

The ink jet head of the present invention is characterized in that a common supply path for supplying ink to each ink chamber is formed on the second substrate. Desirably, each ink chamber has two
They are arranged in rows and the common supply path is located at the center of each of the two rows of ink chambers so as to overlap a part of each ink chamber.

According to this structure, since it is not necessary to form the common supply path on the first substrate, the strength of the first substrate is increased and the manufacturing yield of the ink jet head is improved.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view of a main part of an inkjet printer configured using an inkjet head to which the present invention is applied. The printer head 4, which moves in the left-right direction in the figure by the rail 2, has a flexible cord 6 in which a pipe for ink supply and a line for signal transmission are incorporated.
Is connected to the control unit 8. Printer head 4
Is a platen roll 1 having a rotation axis parallel to the rail 2.
Recording is performed on a recording sheet (not shown) sent by 0. An inkjet head, which will be described below, is built in the printer head 4.

FIG. 2 is a cutaway perspective view of a portion corresponding to one nozzle of the ink jet head. This ink jet head has a first substrate 1 in which an ink chamber 12 is formed.
4 and the nozzle 16 at a position corresponding to the end of the ink chamber 12.
A second substrate 18 on which the ink is formed and a pressure applying unit that applies a pressure to the inside of the ink chamber 12 via the first substrate 14 are provided.

In this example, the pressure applying means includes a piezoelectric element 20 made of PZT or the like attached to the first substrate 14. As the pressure applying means, a heating element can be used instead of the piezoelectric element.

From a common supply path (not shown) to an individual supply path 22
The ink that has been supplied into the ink chamber 12 via is ejected from the nozzle 16 when pressure is applied by the piezoelectric element 20, and recording is thereby performed.

There are a plurality of ink chambers 12 corresponding to the number of nozzles 16. Each ink chamber 12 is arranged in two rows. A conventional example of the arrangement of the ink chambers and the common supply path will be described with reference to FIG.

In FIG. 3, (A) is a front view of each ink chamber and common supply path, and (B) is A in (A).
FIG. The common supply path 24 is used for the first substrate 14
Is formed at the approximate center of the two rows of ink chambers 12. The common supply path 24 communicates with each ink chamber 12 through the individual supply path 22, and thus ink is uniformly supplied from the common supply path 24 to each ink chamber 12.

In such a conventional technique, since the common supply path 24 is formed in the first substrate 14 together with the ink chamber 12, the strength of the first substrate 14 is likely to be lowered,
The problem of low manufacturing yield of inkjet heads is as pointed out above.

The arrangement of the ink chambers and the common supply passage in this embodiment will be described with reference to FIG. In FIG.
(A) is a front view of the ink chamber and the common supply path,
(B) is a BB sectional view in (A). In this embodiment, the common supply path 24 is formed on the second substrate 18. The common supply passage 24 is located at the approximate center of the two rows of ink chambers 12 in the first substrate 14,
Partially overlaps each ink chamber 12. When the length of the overlapped portion is about 5 μm, a sufficient ink supply ability occurs.
The area of the overlapping portion is, for example, about 2500 μm ² .

When the second substrate 18 is, for example, silicon, the common supply path 24 having a triangular cross section can be obtained by anisotropic etching. Isotropic etching or R
The common supply path or the like may be formed by IE (Reactive Ion Etching).

As described above, according to this embodiment, only the ink chamber 12 is formed on the first substrate 14, and the nozzle 16 and the common supply passage 24 are formed on the second substrate 18. There is no possibility of damaging the first or second substrate, and the manufacturing yield of the inkjet head is improved.

Next, an example of the size of each part of the ink jet head in this embodiment will be described in comparison with the conventional one. Figure 5
FIG. 6 is a diagram showing the dimensions of each part in the conventional example. The total length of the first substrate 14 is 45 mm, the length of each ink chamber 12 is 1.0 mm, and the width of the common supply path 24 is 0.5 mm.
Is.

FIG. 6 shows the dimensions of each part of this embodiment when the ink chamber 12 and the common supply path 24 have the same size.
Shown in. In this embodiment, the common supply path 24 is connected to the second substrate 1
Since it is formed in No. 8, the total length can be set to 38 mm, and the inkjet head can be downsized.

When the entire length of the ink jet head is the same as that of the conventional example, as shown in FIG.
2 can be enlarged (1.2 mm) and the driving voltage can be reduced.

[0023]

As described above, according to the present invention,
There is an effect that it becomes possible to provide an inkjet head with a high manufacturing yield.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an inkjet printer.

FIG. 2 is a partially cutaway perspective view of an inkjet head.

FIG. 3 is an explanatory diagram of a common supply path in a conventional example.

FIG. 4 is an explanatory diagram of a common supply path in the embodiment.

FIG. 5 is a diagram showing dimensions of each part in a conventional example.

FIG. 6 is a diagram showing dimensions of each part in the embodiment (No. 1).
Is.

FIG. 7 is a diagram showing dimensions of each part in the embodiment (No. 2).
Is.

[Explanation of symbols]

 12 Ink Chamber 14 First Substrate 16 Nozzle 18 Second Substrate 20 Piezoelectric Element (Pressure Applying Means) 24 Common Supply Path

Claims (4)

[Claims] 1. An inkjet head for ejecting ink from a nozzle (16) by applying pressure to the ink chamber (12) communicating with the nozzle (16), wherein a plurality of ink chambers (12) are formed. Nozzles (16) at positions corresponding to the first substrate (14) and the respective ink chambers (12)
And a pressure applying means (20) for applying a pressure to the ink chamber (12) through the first substrate (14). The second substrate (14, 18) is attached so that the ink chamber (12) is covered by the second substrate (18), and the ink chamber (12) is attached to the second substrate (18). An inkjet head in which a common supply path (24) for supplying ink to the ink is further formed. 2. The pressure applying means (20) is the first substrate.
The inkjet head according to claim 1, further comprising a piezoelectric element (20) attached to (14). 3. The ink chambers (12) are arranged in two rows, and the common supply path (24) is located at the center of each ink chamber (12) in the two rows. The inkjet head according to claim 1, which partially overlaps. 4. The inkjet according to claim 1, wherein the second substrate (18) is made of silicon, and the common supply path (24) is formed by anisotropic etching of silicon to have a triangular cross section. head.