JP3196800B2 - Multilayer inkjet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method in which a thin plate of a piezoelectric vibration plate is attached to a part of a pressure chamber communicating with a nozzle opening, and the pressure chamber is compressed by the piezoelectric vibration plate to generate ink droplets. More particularly, the present invention relates to an ink jet recording head in which a piezoelectric vibration plate, a pressure chamber forming member, and an elastic plate are integrally laminated.

[0002]

2. Description of the Related Art An ink jet type in which a piezoelectric vibrating plate is attached to a part of an elastic plate constituting a pressure generating chamber and the volume of the pressure chamber is changed by bending displacement of the piezoelectric vibrating plate to generate ink droplets. The recording head has a feature that a large area of the pressure generating chamber can be displaced, so that ink droplets can be generated stably. Such a recording head includes an elastic plate 31 having a piezoelectric vibrating plate 30 on its surface to form a vibrating member, as shown in FIG.
A pressure generating chamber forming member 33 that forms the pressure generating chamber 32;
The other surface of the pressure generating chamber forming member 33 is sealed, and the communication hole 35 connecting the pressure generating chamber 32 and the flow path restriction hole 34 and the communication hole 3 connecting the pressure generating chamber 32 and the nozzle opening 41 are formed.
6, a common ink chamber 38 communicating with each pressure generating chamber 32 via a flow path restriction hole 34, and a nozzle opening 4.
1 and a common ink chamber forming plate 40 having a communication hole 39 connecting the pressure generating chamber 32 and a common ink chamber forming plate 40.
And a nozzle plate 42 having a nozzle opening 41 for sealing the other surface, and are sequentially laminated to form an integral unit.

In order to minimize the loss of ink pressure when the pressure generating chamber 32 is compressed, such an ink jet type recording head has a nozzle substantially between the common ink chamber 38 and the pressure generating chamber 32. A flow path restriction hole 34 having a flow resistance of about the opening is provided, and this is a pressure generation chamber 32.
In order to replace the ink cartridge and recover the ejection ability, a cap is placed on the nozzle plate 42, and a negative pressure is applied through the cap to apply ink to the nozzle opening 41 so that the ink is discharged from the nozzle opening 41. When the ink is forcibly discharged, the ink in the common ink chamber 38 is sucked into the nozzle opening 41 through the flow path restriction hole 34, but the amount thereof is extremely small. As described above, the flow does not become a large flow that moves through the entire common ink chamber, and there is a problem that air bubbles that have entered the end of the common ink chamber are stagnant and cannot be eliminated. In order to solve such a problem, the end of the common ink chamber is configured to be tapered as shown in FIG. 2B so that ink stagnation at the end is reduced as much as possible. However, there is a problem in that the area of the common ink chamber is reduced, and it is not possible to ensure sufficient compliance for ink droplet ejection.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and an object of the present invention is to easily eliminate common ink chambers, especially air bubbles at the terminal end, and to provide a common ink chamber. It is an object of the present invention to provide a novel laminated ink jet recording head capable of giving sufficient compliance to the ink chamber of the present invention.

[0005]

According to the present invention, there is provided an elastic plate having a piezoelectric vibrating plate on its surface to form a vibrating member, and one surface of which is sealed by the elastic plate. A pressure generating chamber forming member that is formed to form a pressure generating chamber, while sealing the other of the pressure generating chamber forming member,
A lid member having a communication hole communicating with both ends of the pressure generation chamber, a communication path having a flow path restriction hole for providing flow path resistance to an ink supply path to the pressure generation chamber, and communicating with the pressure generation chamber; A flow path restricting plate having a hole, a common ink chamber communicating with each of the pressure generating chambers via the flow path restricting hole, and a common ink chamber forming plate having a communicating hole communicating with the pressure generating chamber A nozzle plate having a nozzle opening connected to the pressure generating chamber through each of the communication holes while sealing the other surface of the common ink chamber forming plate is sequentially laminated and integrally formed. In the ink jet type recording head, the flow path restricting hole is formed so as to be biased toward a wall surface of the common ink chamber away from the nozzle opening side, and a dummy pressure is generated at an end portion of the common ink chamber. Chamber formed It has been, and to form a plurality of flow path limiting hole in the width direction of the common ink chamber communicated with the pressure generating chamber of the dummy.

[0006]

When the ink is forcibly discharged, the flow path restricting holes communicating with the respective pressure generating chambers are provided adjacent to the wall surface of the common ink chamber. A flow is generated in a direction away from the wall surface, that is, in one direction. As a result, the bubbles in the common ink chamber ride on this flow, are sucked into the pressure generating chamber from the flow path restriction hole, and are discharged from the nozzle opening to the outside. In addition, since a plurality of flow path restriction holes are formed at the end of the common ink chamber, stagnation of the end is reduced, and therefore, the width of the end is increased so that the common ink chamber needs to discharge ink. It is possible to ensure sufficient compliance.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2 are an exploded perspective view showing an embodiment of the present invention and a cross-sectional view showing a structure near a pressure generation chamber connected to one common ink chamber. A driving electrode 5 is formed on a surface of an elastic plate 2 made of a thin plate of zirconia having a thickness of about 10 μm so as to face a pressure generating chamber 4 to be described later, and a piezoelectric vibration plate made of PZT is formed thereon. 3, 3, 3} are fixed.

Reference numeral 7 denotes a spacer, which has a thickness suitable for forming the pressure generating chamber 4, for example, zirconia (Z
pressure generation chambers 4, 4, 4
The through holes 6, 6, 6 which conform to the {shape} are formed at a constant pitch.

The end portion 19b of the common ink chamber 19
As shown in FIG. 3, a dummy pressure generating chamber 4 is formed, that is, a dummy pressure generating chamber 4 which is not particularly involved in printing but is used only for forcibly discharging ink from the nozzle openings. ing.

Reference numeral 8 denotes a lid member for sealing the other surfaces of the pressure generating chamber 4 and the dummy pressure generating chamber 4 '.
First communication holes 10, 10 'connected near the wall surface 4a at one end of the pressure generating chambers 4, 4, 4' and 4 ', and the pressure generating chambers 4, 4, 4'.
, And second communication holes 9 and 9 'communicating with each other at the other end of 4'.

As shown in FIG. 3, one end of each of the first communication holes 10, 10, 10 # has a pressure generating chamber 4, 4, 4 #.
連, 4 'communicate with each other in the vicinity of the wall surfaces 4a, 4a', and the other end protrudes outside the pressure generating chambers 4, 4, 4 ', 4' to form the pressure generating chambers 4, 4, 4 '. ‥ 4 'is formed to be slightly narrower than 4 ′, and the length is such that the liquid that has flowed as a jet at one end can flow out as a laminar flow at the other end, for example, the pressure generating chambers 4, 4, 4 ‥‥, 1 of the total length of 4 '
The length is about / 10.

The three members 1, 5, and 8 are each configured as a unit, and are attached to a flow path restricting plate 11, which will be described later.

Reference numeral 11 denotes a flow path limiting plate which also serves as a unit fixing plate on one surface of which the above-mentioned units are fixed at predetermined positions with an adhesive, and as shown in FIG.
Near the end of the ink chamber 19 and near the wall surface 19a of the common ink chamber 19, a flow path restriction hole 12 having a flow resistance substantially equal to that of the nozzle opening 24 and having the first communication hole 10 side expanded is provided. A communication hole 13 connected to the nozzle opening 31 is provided at a position facing the second communication hole 9, and an ink supply port for supplying ink to a common ink chamber 20 described later by connecting to an ink tank (not shown). 14 are provided.

The first communication hole 10 'communicating with the dummy pressure generation chamber 4' is generally smaller than the flow path restriction hole 12 of the pressure generation chamber 4 as shown in FIG. So that the flow path resistance of the plurality of flow path restriction holes 12 ′, 1 ′ is reduced so that the flow uniformly occurs in the width direction of the terminal end portion 19b.
2 ′ and 12 ′ are provided in the width direction of the end portion 19 b of the common ink chamber 19.

Reference numeral 15 denotes a common ink chamber constituting plate 18 described later.
, A heat-sealing film for joining the flow passage restricting plate 11 with the windows 16 corresponding to the common ink chamber 19, the nozzle openings 24, 24, 24 ° and the pressure generating chambers 4, 4, 4 °.
Communicating holes 17, 17, 17 # are formed.

Reference numeral 18 denotes the common ink chamber forming plate described above.
A thickness suitable for forming the common ink chamber 19, for example, 1
For plate material with corrosion resistance such as 50μm stainless steel,
Windows 20, 20, 20 分岐 branched in a substantially V-shape corresponding to the shape of the common ink chamber 19, and pressure generating chambers 4, 4, 4 ‥
‥ and the nozzle openings 31, 31, 31 ‥‥ are formed with communication holes 21, 21, 21 穿.

Reference numeral 23 denotes a nozzle plate, which has nozzle openings 24, 24, 24 通 communicating with the pressure generating chambers 4, 4, 4 よ り from one side of the pressure generating chamber 4, and a dummy pressure generating chamber 4. , A plurality of nozzle openings 24 ′ 24, 24 ′ communicating with the communication holes 9, 13, 17, 21, 26,.
Common to the adhesive layer 25 such as a heat-sealing film so that ink is supplied from each of the pressure generating chambers 4, 4, 4 'via the communication holes 9', 13 ', 17', 21 ', 26'. Is bonded to the ink chamber forming plate 18.

Reference numeral 27 in the figure denotes a piezoelectric vibrating plate 3, 3,.
Reference numeral 29 denotes a common electrode formed on the surface of 3 °, and 29 denotes a flexible cable for connecting each electrode to an external device.

In this embodiment, when a drive signal is applied to the piezoelectric vibrating plate 3, the elastic plate 2 bends so that the pressure generating chamber 4 side is convex, and the pressure generating chamber 4 is contracted. This allows the ink in the pressure generating chamber 4 to pass through the holes 9, 13, 17, 2
1 and reaches the nozzle opening 24, from which it is ejected as an ink droplet. Since no drive signal is applied to the dummy pressure generating chamber 4 ', no ink is ejected from the nozzle opening 24'.

When the drive signal is removed after the formation of the ink droplets, the piezoelectric vibration plate 3 returns to the original position and the pressure generating chamber 4
Expands. As a result, the ink consumed by the formation of the ink droplets is transferred from the common ink chamber 19 to the flow path restricting hole 12.
And flows into the pressure generating chamber 4 via. Hereinafter, the printing operation is performed by such repetition.

On the other hand, when the ink discharge performance is deteriorated or when the ink tank is replaced, the cap member 28 is pressed against the nozzle plate 23 as shown in FIG. Openings 24, 24, 24 °,
24 ', the ink is forcibly discharged from the nozzle opening 2
An operation is performed to eliminate clogging of the nozzle 4 and air bubbles that have entered the common ink chamber 19 and the pressure generating chamber 4 when the ink tank is replaced.

When the ink is forcibly discharged, the flow path restricting holes 12, 12, 12 発 生 communicating with the pressure generating chambers 4, 4, 4 ‥‥ are formed on the wall surface 1 of the common ink chamber 19.
Since the ink is provided adjacent to the surface 9a, the ink near the wall surface 19a flows from a direction away from the wall surface 19a due to adhesion viscous resistance.

As a result, a flow F1, F1, F1... (FIG. 3A) which is deflected to one side occurs in the common ink chamber 19, and the air bubbles entering the common ink chamber 19 ride on this flow. It is sucked into the pressure generation chambers 4, 4, 4} from the flow path restriction holes 12, 12, 12, and the nozzle openings 24, 24,
It is discharged to the outside from 24.

At the end 19b of the common ink chamber 19, the flow path restricting holes 12 ', 12', 12 'extend in the width direction.
Is formed, and flows into the dummy pressure generating chamber 4 'without stagnation despite the wide width of this region (FIG. 3 (b)). At the same time, a large flow F2 flowing in the axial direction of the common ink chamber 19 is also generated. As a result, air bubbles that are likely to stagnate at the end portion 19b of the common ink chamber 19 are sucked into the dummy pressure generating chamber 4 ', and
Discharged quickly from 4 ', 24', 24 '.

As described above, a flow is generated in the common ink chamber 19 in which the flow is synthesized in a specific direction, that is, toward the end portion 19b and the one wall surface 19a. Bubbles everywhere are formed by this flow, and the flow restricting holes 12, 12, 12 ', 12', 1 '
2 ′, 12 ′ and into the pressure generating chambers 4, 4, 4 ° and the dummy pressure generating chamber 4 ′, and the nozzle openings 24, 2
4, 24 ', 24', 24 ', 24'.

Therefore, it is possible to eliminate air bubbles that have entered the common ink chamber without narrowing the common ink chamber, particularly the end portion 19b thereof, so that sufficient compliance can be imparted to the common ink chamber.

[0027]

As described above, in the present invention,
An elastic plate having a piezoelectric vibration plate on the surface to form a vibration member,
A pressure generating chamber forming member having one surface sealed by an elastic plate to form a pressure generating chamber, the other of the pressure generating chamber forming member being sealed, and first and second communicating at both ends of the pressure generating chamber. A lid member having a communication hole, a flow path restriction plate having a flow path restriction hole for imparting flow path resistance to an ink supply path to the pressure generation chamber, and a flow path restriction plate having a communication hole communicating with the pressure generation chamber; A common ink chamber communicating with each pressure generating chamber via a restriction hole, a common ink chamber forming plate having a communication hole communicating with the pressure generating chamber, and the other surface of the common ink chamber forming plate are sealed. In addition, a nozzle plate having a nozzle opening connected to the pressure generating chamber via each communication hole is sequentially laminated and integrally formed, and a flow path restriction hole is formed in a common ink chamber. Wall away from nozzle opening side Side, and a plurality of flow path restricting holes are formed in the width direction of the common ink chamber in communication with the dummy pressure generating chamber. In the ink chamber, a one-sided flow is generated, and at the end portion, a full-width flow is generated, so that the bubbles in the common ink chamber can be quickly eliminated, so that the common ink chamber can be expanded. Sufficient compliance can be ensured.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are diagrams showing an embodiment of the present invention, respectively, with a sectional structure of a pressure generating chamber and a dummy pressure generating chamber.

FIG. 3 is a diagram illustrating a relationship between a pressure generation chamber and a dummy pressure generation chamber and a common ink chamber, and a flow of ink when ink is forcibly discharged.

FIGS. 4A and 4B are diagrams showing the flow of ink in a pressure generating chamber and a dummy pressure generating chamber when ink is forcibly discharged in the same apparatus, respectively.

FIGS. 5A and 5B are a cross-sectional view showing an example of a conventional laminated ink jet recording head, and a diagram showing the flow of ink in a common ink chamber at the time of forced ejection.

[Explanation of symbols]

 2 Elastic plate 3 Piezoelectric vibrating plate 4 Pressure generating chamber 4 'Dummy pressure generating chamber 7 Pressure generating chamber forming member 8 Cover member 9 Second communication hole 10 First communication hole 11 Flow path restriction plate 12 Flow path restriction hole 12 ′ Flow path limiting hole communicating with dummy pressure generating chamber 18 Common ink chamber forming plate 19 Common ink chamber 19a Wall surface 19b End portion 23 Nozzle plate 24 Nozzle opening 24 ′ Nozzle opening communicating with dummy pressure generating chamber

──────────────────────────────────────────────────続 き Continued on the front page (72) Kazuhiko Hara 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Takahiro Katakura 3-5-5 Yamato, Suwa City, Nagano Prefecture Say (72) Inventor Mari Sakai 3-5-5 Yamato, Suwa-shi, Nagano Prefecture Seiko Epson Corporation (56) References JP-A-5-57894 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055

Claims (2)

(57) [Claims] An elastic plate having a piezoelectric vibrating plate on its surface to form a vibrating member; a pressure generating chamber forming member having one surface sealed by the elastic plate to form a pressure generating chamber; A lid member that seals the other of the forming members and has communication holes that communicate with each other at both ends of the pressure generation chamber; and has a flow path restriction hole that provides flow path resistance to an ink supply path to the pressure generation chamber. A flow restricting plate having a communication hole communicating with the pressure generating chamber, a common ink chamber communicating with each of the pressure generating chambers via the flow restricting hole, and a communication hole communicating with the pressure generating chamber. A nozzle plate having a nozzle opening that seals the other surface of the common ink chamber forming plate and connects to the pressure generating chamber through the communication holes. Each is laminated in order and formed together. In the ink jet recording head having a shape, the flow path restricting hole is formed so as to be deviated toward a wall surface side of the common ink chamber away from the nozzle opening side, and a dummy is provided at an end portion of the common ink chamber. And a plurality of flow path restriction holes formed in the width direction of the common ink chamber in communication with the dummy pressure generation chamber. 2. The multilayer ink jet recording head according to claim 1, wherein a plurality of nozzle openings are formed so as to communicate with the dummy pressure generating chamber.