JP3313089B2 - Inkjet head - 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 recording apparatus such as a printer which forms an ink image on a medium such as recording paper by flying ink droplets, and more particularly to an ink jet printer head.

[0002]

2. Description of the Related Art A pressure generating member in which both ends in the longitudinal direction of a beam-like member composed of a pressure member such as PZT, a metal plate, and a laminated material of ceramic are supported, an ink as a flying medium, and this ink Japanese Patent Publication No. 60-8953 discloses an on-demand type ink jet head which has a nozzle which is a discharge port, and which generates pressure from a pressure generator by an applied voltage and discharges ink from the nozzle. In the inkjet head having this structure, since the piezoelectric transducer is displaced almost perpendicularly to the nozzle forming substrate and the ink flow path of the nozzle meniscus is short, even when foreign matters such as bubbles, dust and the like are mixed in the ink, There is an advantage that normal operation is possible without being affected by this.

[0003]

In the conventional head, since the cavity and the ink tank for supplying ink to the cavity are formed by different members, there is a problem that the head becomes large. In addition, if the cavity and the ink tank are arranged on the same surface in order to reduce the size of the head, there is a problem in that the size increases in the width direction of the head. However, in the conventional head structure, the ink ejection speed,
There has been a limit in reducing the width of the pressure generating member due to restrictions for maintaining various characteristics such as the discharge amount. Therefore,
SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet head capable of maintaining various characteristics such as an ink discharge speed and a discharge amount as desired and reducing the size of the head.

[0004]

In order to achieve the above object, a plurality of nozzles for ejecting ink, a plurality of cavities communicating with each nozzle, and a pressure generating member for applying pressure to the ink in the cavities are provided. An ink jet head comprising an ink tank on one surface side of a flow path substrate forming an ink flow path, and a plurality of cavities on the other surface side arranged to overlap in a plane direction of the flow path substrate, A plurality of ink supply paths corresponding to the plurality of cavities are provided from one surface of the flow path substrate to the other surface, and the ink supply paths are communicated with the ink tank. In the ink jet head, the cavity is formed on a side close to the pressure generating member. Further, in the ink jet head, a nozzle communication hole communicating with the nozzle is arranged at one end of the cavity, and an ink supply path communicating with the ink tank is arranged at the other end. In addition, the ink jet head further includes a nozzle plate having a plurality of nozzles, and the ink tank is configured on a side close to the nozzle plate. In the ink jet head, the length of the cavity in the longitudinal direction is longer than the length of the ink tank in the width direction. Further, in the ink jet head, the ink supply path communicates an end of the ink tank with an end of the cavity. Further, the inkjet head of the present invention includes a plurality of nozzles for discharging ink, a plurality of cavities communicating with each nozzle,
An ink jet head comprising a pressure generating member for applying pressure to ink in the cavity, wherein an ink tank is provided on one surface side of a flow path substrate constituting an ink flow path, and a plurality of cavities are provided on the other surface side. The positions of the end of the ink tank and the end of the cavity are substantially equal, and the ink tank and the cavity are arranged so as to overlap in the surface direction of the flow path substrate. In the ink jet head, a communication hole communicating with the nozzle is arranged at one end of the cavity, and an ink supply path communicating with the ink tank is arranged at the other end. In addition, the inkjet head further includes a nozzle plate provided with a plurality of nozzles, the ink tank is configured on a side closer to the nozzle plate, and the cavity is configured on a side closer to a pressure generating member side. It is characterized by being. In the ink jet head, the cavity and the ink tank are communicated with each other by an ink supply path at an end of the ink tank in a direction away from the nozzle.

[0005]

According to the present invention, an ink tank is arranged on one side of a flow path substrate constituting an ink flow path, and a plurality of cavities are arranged on the other side of the flow path substrate so as to overlap in a plane direction of the flow path substrate. Since a plurality of ink supply paths are provided from one side of the flow path substrate to the other side, and the ink supply paths are communicated with the ink tanks, even if an ink jet head having a high-density cavity structure is formed, the size of the head can be reduced. Can be achieved.

[0006]

FIG. 1 is an overall top view of an ink jet head according to an embodiment of the present invention. Reference numeral 18 denotes a cavity, and the piezoelectric material 12 is formed above the cavity 18 so as to cover the entire head. Piezoelectric material 12
The elastic material 16 is formed on the upper part of the upper surface of the elastic member 16 so as to face the cavity 18, and the pressure generating member 20 is formed.
Reference numeral 14 denotes an ink supply path that leads from the cavity 18 to the ink tank 24. The nozzles 22 are arranged in a diamond shape at the center, and 10 is a nozzle plate on which the nozzles 22 are formed. As shown in the figure, the cavities 18 communicating with the nozzles 22 arranged in a diamond shape, respectively.
Are arranged outside the nozzles arranged in a diamond shape so as to correspond to the respective sides of the diamond shape, and ink is applied to each cavity 18 on the side of the cavity 18 opposite to the side on which the pressure generating member 20 is formed. An ink tank 24 to be supplied is formed.

FIG. 2 shows an aa cross-sectional view in FIG. The piezoelectric material 12 having an Au or nichrome film formed by sputtering on the side facing the cavity 18 is formed as a common electrode 26 on the upper part of the cavity 18. An elastic material 16 is formed on the upper part thereof. When an applied voltage is applied to the elastic material 16 and the common electrode 26, pressure is generated in the pressure generating member 20 which is a laminated material of the piezoelectric material 12 and the elastic material 16, As a result, the pressure of the ink in the cavity 18 increases, and the ink is ejected from the nozzle 22. The ink is stored in the ink tank 24.
From the ink supply path 14. Reference numeral 10 denotes a nozzle plate.

FIG. 3 is an enlarged view of a portion where the nozzles 22 are arranged in FIG. Distance A between nozzles 22
Is 0.28 mm. At this time, the distance B between the outermost nozzles is 3.25 mm. When the nozzles arranged in a diamond shape are divided into sections I and II, the nozzles of section I are designated as 22I and the nozzles of section II are designated as 22II. At this time, 2
Arranged such that 22II is located at the center of 2I. Since this head moves in the X direction in the figure, the density of the nozzles can be increased. This means that the size can be reduced by 88% as compared with the conventional head.

The printing method is based on performing a discharge operation from a nozzle by a conventionally known control means.

As described above, since the density of the nozzles can be increased without reducing the size of the pressure generating member, the printing quality can be improved while securing sufficient power.

FIG. 4 shows a method of manufacturing a head according to an embodiment of the present invention. Cavity 18
And the substrate 30 on which the ink tank 24 is formed (FIG.
In (a)), holes are formed in the ink supply path 14 and the cavity path 32 leading to the nozzles by a laser.
(FIG. 4 (b)). The nozzle plate 10 is fixed thereto by bonding, and a nozzle hole 22 is formed by using a laser. Further, the piezoelectric material 1 is formed so as to cover the entire cavity.
2 is adhered, and the elastic material 16 cut into a predetermined width in advance facing the cavity 18 is fixed with a conductive adhesive or the like to obtain the head shown in FIG.

[0012]

According to the present invention, an ink tank is arranged on one side of a flow path substrate constituting an ink flow path, and a plurality of cavities are arranged on the other side of the flow path substrate so as to overlap in a plane direction of the flow path substrate. A plurality of ink supply paths corresponding to the plurality of cavities are opened from one surface of the flow path substrate to the other surface, and the ink supply paths are communicated with the ink tank, so that an ink jet head having a high-density cavity structure is formed. However, the size of the head can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall top view of an inkjet head according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line aa in FIG.

FIG. 3 is an enlarged view of a nozzle unit in FIG.

FIG. 4 is a diagram illustrating a method for manufacturing an ink jet head according to an embodiment of the present invention.

FIG. 5 is an overall top view of a conventional inkjet head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Nozzle plate 12 Piezoelectric material 14 Ink supply path 16 Elastic material 18 Cavity 20 Pressure generating member 22 Nozzle 24 Ink tank 26 Common electrode 30 Substrate 32 Cavity path

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Noriko Oyama 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (56) References JP-A-1-283153 (JP, A)

Claims (10)

(57) [Claims] 1. An ink jet head comprising: a plurality of nozzles for discharging ink; a plurality of cavities communicating with each of the nozzles; and a pressure generating member for applying pressure to the ink in the cavities. An ink tank is provided on one surface side of a flow path substrate constituting a path, and the plurality of cavities are arranged on the other surface side so as to overlap in a surface direction of the flow path substrate, and a plurality of inks corresponding to the plurality of cavities An ink jet head, wherein a supply path is provided from one surface of the flow path substrate to another surface, and the ink supply path communicates with the ink tank. 2. The ink jet head according to claim 1, wherein the cavity is formed on a side close to the pressure generating member. 3. The ink jet printer according to claim 1, wherein a nozzle communication hole communicating with the nozzle is arranged at one end of the cavity, and an ink supply path communicating with the ink tank is arranged at the other end. Item 3. The inkjet head according to item 1 or 2. 4. The ink jet head according to claim 3, further comprising a nozzle plate provided with the plurality of nozzles, wherein the ink tank is formed on a side close to the nozzle plate. 5. The ink jet head according to claim 1, wherein the length of the cavity in the longitudinal direction is longer than the length of the ink tank in the width direction. 6. The ink jet head according to claim 1, wherein the ink supply path communicates an end of the ink tank with an end of the cavity. 7. An ink jet head comprising: a plurality of nozzles for discharging ink; a plurality of cavities communicating with each of the nozzles; and a pressure generating member for applying pressure to the ink in the cavities. An ink tank provided on one surface side of the flow path substrate constituting the path, and the plurality of cavities provided on the other surface side, wherein the positions of the end portions of the ink tank and the cavities are substantially equal; And the cavity is arranged so as to overlap in a surface direction of the flow path substrate. 8. A method according to claim 7, wherein a communication hole communicating with the nozzle is arranged at one end of the cavity, and an ink supply path communicating with the ink tank is arranged at the other end. The inkjet head according to the above. 9. The ink jet recording apparatus according to claim 1, further comprising a nozzle plate provided with the plurality of nozzles, wherein the ink tank is formed on a side near the nozzle plate, and the cavity is formed on a side near the pressure generating member side. The inkjet head according to claim 7 or 8, wherein: 10. The ink tank according to claim 7, wherein the cavity and the ink tank are communicated with each other by an ink supply path at an end of the ink tank in a direction away from a nozzle. Ink jet head.