JPH03187757A - Liquid drop jetting device - Google Patents

Abstract

PURPOSE:To achieve reduction of cost of a liquid drop jetting device by a method wherein a passage block of the liquid drop jetting device is composed of an Si base material. CONSTITUTION:A liquid drop jetting device is composed by being equipped with a base block 1 consisting of zircon and lead titanate base material, a covering plate component 2 consisting of a photosensitive glass or stainless steel and others, and a passage block 3 consisting of a Si base material. When voltage is impressed to a required signal electrode 6, a laminated piezoelectric element 7 is deformed, and a vibrating plate part of the covering plate component 2 corresponding to the piezoelectric element 7 is deformed. Variation in pressure is generated in a corresponding pressure chamber 15b, and a liquid drop is jetted from an orifice 17. Since the passage block 3 is composed of a Si base material and the silicon base material is of low cost because of a comparatively great amount of production thereof, reduction of cost of the liquid drop jetting device which uses such a passage block 3 can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a droplet ejecting device applied to, for example, a drop-on-demand inkjet head that ejects ink droplets to record on paper.

[Conventional technology]

Droplet ejecting devices applied to inkjet heads have traditionally utilized heating elements to generate droplets (
(see Japanese Patent Laid-Open No. 60-204374), and those using piezoelectric elements are known. Furthermore, a member using a Si base material as a member having an orifice for ejecting droplets is known (see Japanese Patent Laid-Open No. 116656/1983).

A droplet ejecting device that uses a piezoelectric element uses the piezoelectric element to cause a change in the volume of a liquid chamber filled with ink, and a pressure change in the liquid chamber due to this change in volume causes a droplet to flow through the liquid chamber to the outside. Ink droplets are ejected from an open orifice.

For example, as shown in FIG. 4, a droplet ejecting device including a piezoelectric element includes a base block 31 made of a PZT (zircon lead titanate) substrate, a cover plate member 32 made of glass or stainless steel, and a photosensitive material. The channel block 33 is made of glass.

In the base block 31, the first PZT substrate 3
4 is covered with a ground electrode 41, and comb-like protrusions 35 are formed on this ground electrode 41. Among the protrusions 35, those having the signal electrodes 36 become the laminated piezoelectric elements 37.

A cover plate member 32 is fixed to the base block 31 with an epoxy adhesive. The cover plate member 32 is formed to have a thickness of approximately 50 μm in order to function well as a diaphragm.

The cover plate member 32 has a passage block 33 made of ultraviolet curing resin.
is fixed. As shown in FIG. 5, a groove 43 is formed in the channel block t7 33.
is covered with the cover plate member 32, thereby forming a liquid chamber 45.

Micro grooves are formed on the tip side of the channel block 33 at positions corresponding to the respective liquid chambers 45, and are covered with the cover plate member 32 to form orifices 47. It has become.

The grooves 43 that will become the liquid chamber 45 and the minute grooves that will become the orifice 47 are formed by selectively irradiating ultraviolet rays onto the parts of the photosensitive glass that will become the flow path block 33 that correspond to the grooves 43, etc. Easily soluble (formed by etching, etc.)

[Problem to be solved by the invention]

However, in the conventional droplet ejecting device, photosensitive glass is used for the flow path block 33 in consideration of ease and accuracy of etching, as described above, but this photosensitive glass Since it incorporates metals such as Au, Ag, and Ce into the metal, and the etching rate can be changed, it is relatively expensive, and has the disadvantage that the droplet jetting device is relatively expensive. ing.

[Means to solve the problem]

In order to solve the above-mentioned problem, the droplet ejecting device according to the present invention uses one wall of the liquid chamber formed by the groove of the flow path block and the cover plate member that covers the groove as a diaphragm. A droplet ejecting device that vibrates this with a piezoelectric element and causes a pressure change in a liquid chamber by the vibration to eject droplets, characterized in that the flow path block is made of a Sil material. .

[For production]

In the above configuration, the flow path block is made of a Si base material, and this Si base material is produced in relatively large quantities and is inexpensive. It is possible to reduce the −
In particular, when used as an inkjet recording head in a color printer, several droplet ejecting devices are provided, so the cost reduction in the color printer is significant.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 2, the droplet jetting device according to the present invention has P
It is composed of a base block 1 made of a ZT (zircon lead titanate) substrate, a cover plate member 2 made of photosensitive glass or stainless steel, and a flow path block 3 made of a Si base material.

In the base block 1, as shown in FIG. 1, the first PZT substrate 4 is covered with a ground electrode 11, and the ground electrode 11 is covered with comb-like protrusions 5... is formed. Among the convex portions, those having the signal electrodes 6 constitute the laminated piezoelectric elements 7.

This laminated piezoelectric element 7 includes a second PZT substrate 8 and a signal electrode 6.
, a third PZT substrate 1°, and an upper ground electrode 11' formed in the form of an electrical connection rod to the ground electrode 11. Base block l has a thickness of 200
The first second PZT substrate 8 and the third PZT are sheet-like in the order of μm.
between the substrate 10 and the third PZT substrate 10.

After laminating the electrode layers and firing them, the convex portion 5 is
Dicing process to obtain signal electrode 6...
It can be obtained by performing electrode etching and insulating coating etc. to obtain this.

A cover plate member 2 is fixed to the base block 1 with an epoxy adhesive. The cover plate member 2 is formed to have a thickness of approximately 50 μm in order to function well as a diaphragm.

A channel block 3 is fixed to the cover plate member 2 using an ultraviolet curing resin. As shown in FIG. 3, a groove 13 having a depth of about 20 to 100 μm is formed in the channel block 3, and by covering this groove 13 with the cover plate member 2, the liquid can be removed. A chamber 15 is formed, and a liquid chamber 15 is formed in the cover plate member 2.
The portion constituting the diaphragm functions as a diaphragm section.

The liquid chamber 15 consists of a liquid distribution chamber 15a and a pressure chamber 15b. The liquid distribution chamber 15a is communicated with a liquid supply device (not shown) through a liquid supply hole 16 formed in the channel block 3. Each pressure chamber 15b is formed at a position corresponding to the laminated piezoelectric element 7, and communicates with the liquid distribution chamber 15a via the constricted portion 15c to receive liquid supply, while being By forming a closed space, the volume of the liquid distribution chamber 15a and other pressure chambers 15b can be changed independently.

On the front end surface side of the flow path block 3, a minute groove with a depth of about 20 to 100 μm is formed at a position corresponding to each pressure chamber 15b, and is covered with the cover plate member 2. An orifice 17 is adapted to be formed.

To obtain the flow path block 3, portions corresponding to the minute grooves that will become the grooves 13 and orifices 17 are formed by anisotropic etching of Si.

In the droplet ejecting device having the above configuration, by applying a voltage to a desired signal electrode 6, only the corresponding laminated piezoelectric element 7 is deformed, and the cover plate member corresponding to this laminated piezoelectric element 7 is deformed. Only the second diaphragm portion is deformed, a pressure change occurs only in the corresponding pressure chamber 15b, and droplets are ejected only from the orifice 17 corresponding to this pressure chamber 15b.

In such a droplet ejecting device, the wave path block 3
is made of a Si base material, and this Si base material is produced in relatively large quantities and is inexpensive. Therefore, it is desirable to reduce the cost of a droplet ejecting device using such a flow path block 3. I can do it.

In this embodiment, the orifices 17 are formed by minute grooves in the flow path block 3, but instead of this, the wide state of the pressure chamber 15b is extended to the tip surface of the flow path block 3. In addition to extending the flow path block 3, an orifice plate having orifices formed in predetermined positions may be attached on the front end surface of the flow path block 3.

Moreover, as a piezoelectric element, PZT substrates are laminated to form a laminated piezoelectric element 7, but a single PZT substrate is used. A piezoelectric element may be formed by T.

〔Effect of the invention〕

As described above, the droplet ejecting device according to the present invention has a structure in which the flow path block is made of a Si base material.

This has the effect of reducing the cost of the droplet jetting device.

FIG. 3 is a perspective view of the channel block.

4 and 5 show conventional examples.

FIG. 4 is a longitudinal sectional view of the droplet ejecting device.

FIG. 5 is a perspective view of the channel block.

1 is a base block, 2 is a cover plate member, 3 is a channel block, 7 is a laminated piezoelectric element, 13 is a groove, 15 is a liquid chamber, and 17 is an orifice.

Claims (1)

[Claims] 1. One wall of the liquid chamber formed by the groove of the flow path block and the cover plate member covering the groove is used as a vibration plate and is vibrated by a piezoelectric element. A droplet ejecting device that ejects droplets by causing a pressure change in a liquid chamber, characterized in that the flow path block is made of a Si base material.