JP3254863B2 - Ink jet recording 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 on-demand type ink jet recording head for ejecting ink droplets according to input information and forming characters and figures on a recording medium by dots.

[0002]

2. Description of the Related Art A number of ink jet recording heads have been proposed in which a vibration plate is displaced by deformation of a piezoelectric element and ink droplets are ejected by increasing ink pressure in a pressure chamber. It has been proposed in recent years. For example, there has been proposed a method in which a pressure chamber is formed by binder removal processing using an ink jet recording head in which a vibration plate and a nozzle are integrally fired with a piezoelectric material itself (Japanese Patent Application Laid-Open No. 62-1014).
No. 55).

[0003] In such an integral firing type ink jet recording head, it is not necessary to process and form the piezoelectric elements into a predetermined size, and to adhere each of them with an adhesive, and to simultaneously form the pressure chambers and nozzles by debinding. This greatly simplifies the assembly process.

[0004]

However, in the above-described integral firing type ink jet recording head,
It has been found that the following problems occur. That is, in the integrally fired ink jet recording head in which the diaphragm and the nozzle are made of a piezoelectric material, even if mechanical processing or laser processing is performed on the piezoelectric material, the cross-sectional shape of the nozzle cannot be made to be a perfect circle, There was a problem that the processing accuracy could not be improved.

The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to integrally form a vibration plate, a pressure chamber forming plate and a nozzle plate by firing , and thereafter to form a signal applying electrode and a piezoelectric element. In the ink jet recording head for forming the ink supply path, a press working or a laser processing can be used as a processing method of the ink supply path or the nozzle by providing the ink supply path penetrating through the pressure chamber forming plate. And to improve the processing accuracy of the nozzle. Ultimately, the object is to stabilize the flight of ink droplets and to form uniform characters and graphics on a recording medium without unevenness.

[0006]

SUMMARY OF THE INVENTION An ink jet recording head according to the present invention comprises a ceramic nozzle having a nozzle formed thereon.
Hole and a plurality of pressure chambers communicating with the nozzle.
A pressure chamber forming plate made of ceramic,
Ceramic laminated on the chamber forming plate and sealing the through hole
Diaphragm formed at a position corresponding to the pressure chamber
Having a piezoelectric element, the nozzle plate, the pressure chamber forming plate,
The vibration plate and the piezoelectric element are sequentially laminated and fired.
An integrally formed inkjet recording head
The pressure chamber communicates with an ink reservoir chamber connected to ink storage means via a communication passage formed in the nozzle plate and an ink supply passage formed in the pressure chamber formation plate. It is assumed that.

[0007]

According to the present invention, the ink supply path and the nozzle are press-formed into a green sheet material in advance by providing the ink supply path in the pressure chamber forming plate and providing the nozzle plate with a communication path connecting the pressure chamber and the ink supply path. Alternatively, it can be formed by laser processing. In addition, after firing the vibration plate, pressure chamber forming plate, nozzle plate, signal application electrode, and piezoelectric element integrally, the ink supply path and nozzle can be formed by laser processing, so that the processing cross section can be made circular. In addition, good processing accuracy can be ensured.

[0008]

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

FIG. 1 is an exploded perspective view showing the overall configuration of an embodiment of the ink jet recording head of the present invention. Pressure chamber forming plate 4 having a plurality of piezoelectric elements 1, electrodes 7, diaphragm 2, a plurality of pressure chambers 3 corresponding to piezoelectric elements 1, and nozzle 5
An FPC 110 for sending an applied signal is joined to the ink jet recording head 10 constituted by the nozzle plate 6 having the nozzles 6 so that the electrodes 7 can be electrically connected, and then a fixing plate 120 having a filter (not shown) is joined. The ink cartridge 130 has a foam inside and holds the ink, and is joined to the fixing plate 120 while ensuring a sealing property. The ink jet recording head 10 is generally fired integrally, but can be joined by a method other than firing. Also, in FIG.
Although the ink jet recording heads 10 are arranged in rows, the number of nozzles and the number of rows are not limited to any combination.

Next, a more detailed configuration will be described with reference to FIG. 2 which is a plan view seeing through the pressure chamber and FIG. 3 which is a sectional view of the pressure chamber.

In FIG. 3, one of the pressure chamber forming plates 4 has a vibration plate 2 and the other has a nozzle plate 6 having a nozzle 5 to form the pressure chamber 3. An electrode 7 for applying a print signal is formed on the surface of the diaphragm 2 and a plurality of piezoelectric elements 1
Are formed corresponding to the plurality of pressure chambers 3. The ink supply passage 8 penetrates at right angles to the plane of the pressure chamber forming plate, and passes through the communication passage 9 formed in the nozzle plate 6 to form the pressure chamber 3.
Is in communication with Inside the ink reservoir 121 formed integrally with the fixing plate 120, the ink reservoir chamber 12 is provided.
2 are provided and communicate with the inlet 8A of the ink supply path. In FIG. 2, the electrodes 7 are alternately arranged at positions not overlapping the inlet 8A of the ink supply path.
In the portion corresponding to the electrode 7, the ink reservoir 121 and the diaphragm 2 are joined so that the electrode 7 is bent in the height direction. This prevents the electrodes from being short-circuited by the ink. FIG. 4 shows a second embodiment of the present invention, in which an ink reservoir chamber 90 is provided in the pressure chamber forming plate 4. Incubator room 9
Ink is supplied from the ink cartridge 130 through the fixing plate 120 and the ink reservoir 121 to 0.

In such a configuration, the ink guided from the ink cartridge 130 is supplied to the ink reservoir chamber 122,
The ink passes through the ink supply path 8 and the communication path 9 and reaches the pressure chamber 3. Initially, auxiliary means such as suction from a nozzle may be used, but once filled, ink is replenished as needed by the capillary force of the channel itself. When a printing operation is performed, a driving circuit (not shown) supplies an FPC
A voltage of 15 to 50 V according to the input signal is applied to the piezoelectric element 1 via 110. The piezoelectric element 1 is displaced and presses the ink in the pressure chamber 3 by bending the deformable diaphragm 2 . The ink in the pressure chamber 3 instantaneously moves in the direction of the nozzle 5 and the ink supply path 8 in response to this, but ink droplets are ejected from the nozzle 5 to the outside.
When the piezoelectric element 1 is displaced in the opposite direction, ink flows into the pressure chamber 3 to prepare for the next ejection. Repeating the above operation enables continuous recording. Also, an ink jet recording head that ejects ink droplets corresponding to the recording data, an ink image holding unit that receives the ink droplet and is elastically deformable, and a pressing roller that can advance and retreat to a transfer area of the ink image holding unit. The ink image holding means and the pressing roller are provided with a predetermined rotational speed difference so that the ink image holding means is slid when a nip pressure is applied to the ink image holding means.

Next, a method of manufacturing the above-described ink jet recording head will be described with reference to FIG.

A ceramic material having a thickness suitable for the diaphragm 2 when fired and having a through hole formed by pressing, in this embodiment, a zirconia green sheet 2
And a zirconia green sheet 4 having a thickness suitable for forming the pressure chamber 3 and punching through the pressure chamber 3 and the ink supply passage 8 pierced by a press, and punching out a nozzle 5 pierced by the press. A zirconia green sheet 6 having a communication path 9 formed by applying pressure with a mold to a depth suitable for 9 is prepared. The method of applying pressure to a zirconia green sheet with a mold is much easier than the processing of metal or resin (FIG. 5).
(A)).

The three green sheets 2, 4, and 6 are stacked and uniformly fired at a temperature of 800 ° C. to 1500 ° C. by applying a uniform pressure. The ceramic material is generally a material mainly containing at least one of aluminum oxide, zirconium oxide, magnesium oxide, aluminum nitride, and silicon nitride. As a result, each sheet changes to ceramics, and at the same time, at the boundary surface of each sheet, the three sheets are united by the sintering action as if they were originally composed of one sheet. (FIG. 5 (b).

In this state, a conductive paste material for forming the electrode 7 is formed on the surface of the vibration plate 2 at a portion corresponding to the pressure chamber 3 by a thick film printing method, and baked. The material of the electrode 7 is a material mainly composed of at least one of platinum, palladium, silver-palladium, silver-platinum, and platinum-palladium alloy. Next, the material for the piezoelectric element 1 is formed by printing, and is baked to finish. The material of the piezoelectric element 1 is a material mainly containing lead zirconate titanate, lead magnesium niobate, lead nickel niobate, lead zinc niobate, lead manganese niobate, lead antimony stannate, and lead titanate. (FIG. 5 (c)).

When the piezoelectric element 1 is formed, an insulating layer 320 as shown in FIG. 7 is formed between the piezoelectric elements 1. Thereafter, when the common electrode 300 is formed by a film forming technique such as sputtering so as to cover the piezoelectric element 1, all the above-described members are integrally formed.

FIG. 6 shows another embodiment of the method for manufacturing an ink jet recording head according to the present invention.

A ceramic material having a thickness suitable for the diaphragm 2 when fired, in this embodiment a green sheet 2 of zirconia, and a pressure chamber having a thickness suitable for forming the pressure chamber 3 and penetrated by a press 3 and a zirconia green sheet 6 in which a communication passage 9 is formed by applying pressure with a mold to a depth suitable for the communication passage 9 by pressing to prepare a zirconia green sheet 4. The layers 4 and 6 are stacked, and a uniform pressure is applied, and the layers are integrally fired at a temperature of 800 ° C. to 1500 ° C. as in the manufacturing method of FIG. As a result, each sheet changes to ceramics, and at the same time, at the boundary surface of each sheet, the three sheets are united by the sintering action as if they were originally composed of one sheet. The difference from FIG. 5 is that the ink supply path and the nozzle are not provided in advance. (FIG. 6 (a)).

In this state, similarly to FIG. 5, a conductive paste material to be the electrode 7 is formed on the surface of the vibration plate 2 in a portion corresponding to the pressure chamber 3 by a thick film printing method, and baked. Next, the material for the piezoelectric element 1 is formed by printing, and is baked to finish.

(FIG. 6B).

After being integrally fired until the piezoelectric element is formed, the diaphragm 2 is first processed by laser processing A.
And an ink supply path 8 penetrating the pressure chamber forming plate 4. Next, the nozzle 5 penetrating through the diaphragm 2 and the nozzle plate 6 is formed by laser processing A. Since the pressure chamber 3 in the pressure chamber forming plate 4 has been processed to the position corresponding to the nozzle when processing in advance, it is not necessary to perform laser processing. The hole processed in the diaphragm 2 is finally sealed. Further, the nozzle 5 can be processed by laser processing from the direction B. (FIG. 6
(C)).

[0023]

According to the present invention, in the ink-jet recording head of the integral firing type, the ink supply passage is provided in the pressure chamber forming plate, and the nozzle plate is provided with a communication passage for communicating the pressure chamber with the ink supply passage. As a result, it has become possible to employ press processing or laser processing in which the ink supply path and the nozzle have a perfect cross section and a high precision with a perfect cross section. In addition, since the integrally fired ink jet recording head has been made possible, all the flow paths can be made of ceramics without using an adhesive, so that the degree of freedom of the ink used can be greatly expanded.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing the entire configuration of the present invention.

FIG. 2 is a plan view seen through a pressure chamber of the present invention.

FIG. 3 is a sectional view showing a pressure chamber of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a view showing a manufacturing method of the present invention.

FIG. 6 is a view showing another manufacturing method in the present invention.

FIG. 7 is a sectional view showing an electrode part of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Vibration plate 3 Pressure chamber 4 Pressure chamber forming plate 5 Nozzle 6 Nozzle plate 7 Electrode 8 Ink supply path 9 Communication path 10 Ink jet recording head

Claims (3)

(57) [Claims] 1. A ceramic nozzle having a nozzle formed thereon.
The plate and a plurality of pressure chambers communicating with the nozzles have through holes.
A formed pressure chamber forming plate made of ceramic;
Ceramic layered on the forming plate to seal the through hole
And a pressure plate formed at a position corresponding to the pressure chamber.
The nozzle plate, the pressure chamber forming plate, the vibrating plate, the pressure
And the elements were laminated in order, and formed integrally by firing.
An ink jet recording head, wherein the pressure chamber has a communication passage formed in the nozzle plate,
The ink is supplied through an ink supply passage formed in the force chamber forming plate.
In communication with an ink reservoir chamber connected to the storage means
An ink jet recording head, characterized in that: 2. An ink jet recording head according to claim 1,
In the method of manufacturing, suitable for forming a step constituting the diaphragm bored a hole penetrating the green sheet of ceramic material having a thickness suitable for forming a vibration member, a pressure chamber A step of forming a pressure chamber forming plate by piercing the pressure chamber penetrating a green sheet of a ceramic material having a thickness, and a penetrating ink supply path, and a ceramic having a thickness suitable for forming a nozzle Forming a nozzle plate by piercing the penetrating nozzle in a green sheet of material, and further forming a communication path for communicating the pressure chamber with the ink supply path; and forming the vibration plate comprising a green sheet of ceramic material. Laminating a plate, the pressure chamber forming plate, and the nozzle plate in the above order and firing them integrally; and forming an electrode material corresponding to the pressure chamber to form a signal applying electrode. And a step of forming a piezoelectric material on the signal applying electrode and firing the piezoelectric element. 3. An ink jet recording head according to claim 1,
In the method for manufacturing a metal plate, a step of laminating a vibrating plate, a pressure chamber forming plate and a nozzle plate made of a green sheet of a ceramic material and firing them integrally, forming an electrode material corresponding to the pressure chamber and applying a signal Baking an electrode, forming a piezoelectric material on the signal applying electrode and baking a piezoelectric element, and forming the vibrating plate, the pressure chamber forming plate, the nozzle plate, the signal applying electrode, and the piezoelectric element. Forming an ink supply path on the vibrating plate and the pressure forming plate, and forming a nozzle on the nozzle plate after integrally firing.