JP2003341057A - Liquid ejection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection head equipped with a reservoir capable of enhancing the strength of a region facing the ejecting liquid inlet of a spacer by such an extent as not causing a decrease in yield. <P>SOLUTION: A recess 18 for making an opening 18a on the reservoir side is formed in the region of the spacer 15 not forming a channel, and a supporting part 19 is formed of a totally thick part facing a holder 6 in the region of the reservoir 3. Opening of an ejecting liquid introduction passage 12 is secured oppositely to the recess 18. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejecting head that pressurizes a liquid in a pressure generating chamber to eject liquid droplets by a pressurizing means, and more particularly to a structure of a spacer as a flow path forming substrate that constitutes the liquid ejecting head. .

[0002]

2. Description of the Related Art A recording head used in an image recording device such as a textile printing device, a microdispenser, a printer, a coloring agent jetting head used for manufacturing a color filter of a liquid crystal display, an organic EL display, a surface emitting display
Liquid ejecting heads for ejecting liquid, such as electrode forming agent ejecting heads used for forming electrodes such as (FED) and bio-organic substance ejecting heads used for manufacturing biochips, and liquid ejecting heads as liquid droplets generate pressure that communicates with nozzles. An elastically deformable sealing plate is laminated on the wall surface of the chamber, and the liquid droplets to be ejected are ejected by pressing the sealing plate with a piezoelectric vibrator. For example, as shown in Patent Document 1, it has a nozzle. A nozzle plate, a pressure generating chamber, a spacer member in which a reservoir and an injection liquid flow path are formed, and a sealing plate are laminated in a sandwich shape, and the sealing plate is elastically deformed by a piezoelectric vibrator to generate the pressure generating chamber. Is configured to expand and contract. The reservoir is formed with a through hole so as to extend in the direction in which the pressure generating chambers are arranged, and is connected to the liquid injection port at the center of the through hole. For this reason, there is a problem that the strength of the region in contact with the injection liquid introduction port is small, and defective adhesion is likely to occur. In order to solve such a problem, as seen in Patent Document 2, at least the outer circumference of the opening of the injection liquid guide path is provided around the region of the spacer facing the injection liquid introduction port in the direction crossing the reservoir. It has also been proposed to form a region that supports two points.

[Patent Document 1] JP-A-7-323543

[Patent Document 2] Japanese Patent Laid-Open No. 11-245399

[0003]

According to this, although the strength is increased to some extent, the injection liquid introducing port is formed as a through hole similarly to the reservoir, so that bending is likely to occur and sufficient strength is obtained. Can't be said to have. The present invention has been made in view of such a problem, and an object of the present invention is to sufficiently increase the strength of a region of a spacer that faces an injection liquid inlet of a spacer to such an extent that yield does not decrease. A liquid ejecting head having a reservoir capable of

[0004]

In order to solve such a problem, according to the present invention, a plurality of pressure generating chambers are formed in a row, and the pressure generating chambers in each row are provided with an injection liquid supply port. Is formed by stacking a spacer forming a reservoir communicating with the pressure generating chamber, a nozzle plate having a nozzle opening communicating with the pressure generating chamber, and a sealing plate sealing the pressure generating chamber and the reservoir. A flow path unit, and a head holder that fixes the flow path unit and that has an injection liquid guide path that supplies an injection liquid to the reservoir, and in the spacer non-formation region, A concave portion opening to the reservoir side is formed, and a support portion having a full thickness is formed in the region of the reservoir and in a region facing the holder, and the opening of the injection liquid guiding path faces the concave portion. Fixed To have.

[0005]

The liquid to be injected flows into the reservoir from the liquid guide path for the liquid to be injected through the opening on the reservoir side of the recess. The periphery of the opening of the liquid injection guide path is in contact with the non-etched portion of the spacer and the full-thickness portion of the reservoir, and the area facing the opening of the liquid injection guide path is a continuous body. Maintain strength. Thereby, the liquid to be ejected necessary for printing can be supplied to the reservoir from the liquid to be ejected guide path through the opening on the reservoir side of the concave portion, and the opening of the liquid to be ejected guide has a peripheral edge in the non-etched portion of the spacer. In addition, it is possible to maintain a sufficient strength by contacting the entire thickness portion of the reservoir and the region facing the opening of the liquid injection guide path is a continuous body.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows an embodiment of a liquid ejecting head of the present invention by taking a recording head as an example, in which a nozzle opening 1, an ejected liquid supply port 2, a reservoir 3 and a pressure generating chamber 4 are formed. The flow path forming unit 5 is fixed to one end of the head holder 6, and the tips of the piezoelectric vibrators 7, 7, 7, ... Abut on the positions of the units 5 facing the pressure generating chambers 4 in each row. The piezoelectric vibrator unit 8 is fixed to the head holder 6 and configured.

As shown in FIG. 2, the head holder 6 has a window 9 for exposing the piezoelectric vibrators 7, 7, 7 at a position facing the pressure generating chamber 4, and a region facing the reservoir 3,
The piezoelectric vibrator 7 forms a recess 11 that elastically deforms a later-described sealing plate 10 that is elastically deformable, and further, a liquid ejection guide path 12 is provided at a position facing the center of the reservoir.
Is formed by forming an opening 13 at the tip.

The flow path unit 5 includes at least a nozzle plate 14 having a nozzle opening 1 communicating with the pressure generating chamber 4, a reservoir 3, a jetted liquid supply port 2, and a spacer 15 forming the pressure generating chamber 4. The opening 13 of the head holder 6 and the reservoir 3 are formed in an elastic film that seals the reservoir 3, the liquid to be injected 2 and the pressure generating chamber 4 and that is elastically deformable in the region of the reservoir 3 and the pressure generating chamber 4. It is configured by laminating a sealing plate 10 formed by forming an injection liquid introducing port 16 to be connected, in a sandwich shape.

In this embodiment, the sealing plate 10 is provided with an island portion 17 having rigidity in the center line of each pressure generating chamber in order to convert the displacement of the piezoelectric vibrator 7 into a change in volume of the pressure generating chamber. ing.

FIG. 3 shows an embodiment of the spacer 15, which is made of a material capable of chemically etching a pattern formed by photolithography, such as a metal or silicon single crystal substrate. . In this embodiment, a silicon single crystal substrate having a thickness suitable for forming a spacer is used, and the pressure generating chambers 4, 4, 4, ... Are arranged in two rows at a constant pitch so that the center line is a symmetry line. Formed by
Outside the injection liquid supply ports 2, 2, 2, ... In each row, reservoirs 3 and 3 are independently formed as through holes, that is, by full etching, leaving a supporting portion described later,
The pressure generating chambers 4, 4, 4, ... Of each row are connected to the reservoirs 3, 3 via the liquid injection ports 2, 2, 2.

In this embodiment, the reservoir 3 is formed such that both sides thereof are slightly narrowed so that the center point is the symmetry point, passes through the center line, and is exposed to the non-etching region side, that is, the region outside the reservoir. A recess 18 is formed by half etching so as to face the opening 13 of the liquid guide path 12 (see FIG.
Cross-hatched area) is formed, and the support portion 1 having the same thickness as the total thickness of the spacer 15 is formed so as to face the recess 18.
9 is formed.

As shown in FIG. 4B, the recess 18 is formed with an opening large enough to supply the jetted liquid from the jetted liquid guiding path 12 in accordance with the consumption of the jetted liquid during printing. The depth d is set so that the strength can be maintained as much as possible.

In this embodiment, the nozzle plate 14 is provided on one surface of the spacer 15 and the sealing plate 1 is provided on the other surface.
0 is liquid-tightly fixed with an adhesive or the like to form the flow path forming unit 5
Make up.

The liquid injection port 16 of the flow path forming unit 5 is connected to the opening 13 of the liquid injection guide path 12 of the head holder 6.
Is fixed to the head holder 6 with an adhesive or the like, and the piezoelectric vibrator unit 8 is fixed to the head holder 6 so that the tip of the piezoelectric vibrator 7 contacts the island portion 17 of the sealing plate 10, Further, the recording head is completed by attaching the jetted liquid supply needle 21 and the filter 22 to the other surface of the head holder 6 and fixing the outer side with a frame 23 which also serves as a shield member.

By the way, in the process of adhering the flow path unit 5 and the head holder 6, the region of the jetted liquid introduction path 12 facing the opening 13 is formed as a half-etched portion,
Moreover, since the support portion 19 is formed in the reservoir 3,
The sealing plate 10 around the opening 13 of the liquid to be ejected guide path 12 is reliably adhered to the head holder 6 and a liquid-tight structure is secured.

When a drive signal is applied to the recording head thus constructed, the piezoelectric vibrator 7 contracts and the pressure generating chamber 4
Expands. As a result, the liquid to be ejected (ink when used as a recording head) in the reservoir 3 flows into the pressure generating chamber 4 from the liquid to be ejected supply port 2. When the piezoelectric vibrator 7 is discharged after a predetermined time has elapsed, the piezoelectric vibrator 7 expands and returns to the original state. In this process, the pressure generating chamber 4 is compressed and the liquid to be ejected in the pressure generating chamber 4 is ejected from the nozzle opening 1 as ejected liquid droplets (ink droplets).

When the liquid to be ejected in the reservoir 3 is consumed in this manner, the liquid to be ejected from the liquid to be ejected cartridge (not shown) connected by the liquid to be ejected needle 21 is guided to the liquid to be ejected path of the head holder 6. The liquid to be ejected (12) from the liquid to be ejected inlet 16 through the opening 18a of the recess 18 (see FIG.
The arrow K in (b) flows into the reservoir 3.

Further, in the above-described embodiment, one connection flow path between the opening 13 of the liquid injection guide path 12 of the head holder 6 and the reservoir 3 is formed in the extension direction of the reservoir 3. In the reservoir 3, the above-mentioned concave portion 18 and supporting portion 19 are provided.
By forming a plurality of pairs, the flow path resistance of the connection flow path can be reduced.

FIG. 5 shows another embodiment of the present invention in a region facing the opening 13 of the liquid injection guide path 12 of the head holder. In this embodiment, the recess 1 is formed.
A wall 18 b ′ that partitions 8 ′ is formed inside the opening 13 of the liquid injection guide path 12, that is, at a position retracted from the reservoir 3, and a recess 18 is formed in a region facing the opening 13 of the liquid injection guide path 12. 'And a through-hole 20 having an opening on the reservoir side, that is, a region having the same depth as the reservoir 3 is present.

According to this embodiment, the injection liquid guide path 12
Since there is a recess 18 ′ that is continuous with non-etching in a region facing the opening 13 of the
As compared with the case where the region facing 3 is formed as a complete through hole, it is reinforced. As a result, the outer peripheral portion of the opening 13 of the liquid to be ejected guide path 12 comes into contact with the non-etching region of the spacer 15 and the support portion 19, and the sealing plate 10 is reliably bonded to the head holder 6. On the other hand, since the opening 13 of the injected liquid guiding path 12 faces the penetrating portion 20 of the spacer 15, the injected liquid K flowing from the injected liquid guiding path 12 flows into the reservoir 3 with a small flow resistance. The position of the wall 18b 'that defines the recess 18', that is, the recess 1
The ratio between 8 ′ and the penetrating portion 20 can be appropriately set in consideration of the flow path resistance and the strength. In addition, this penetrating portion 2
0 can be easily formed by performing etching such that the etching surface 18c ′ is exposed when the reservoir 3 formed of the through hole is formed.

Further, in the above-mentioned embodiment, the silicon single crystal substrate which is easy to form a recess by deeply etching with a high precision is used. However, a metal or glass which can be etched and has corrosion resistance against the liquid to be jetted is used. Using a plate material such as
To form a through region or a recess in this by etching,
Further, it can be configured by disassembling into a plurality of layers in the thickness direction so that at least the bottom surface of the concave portion serves as a boundary, and laminating an etching film having a through hole corresponding to the through hole of each layer.

Further, in the above-mentioned embodiment, the piezoelectric vibrator which expands and contracts in the axial direction is used as the pressurizing means, but a piezoelectric vibrator which flexibly oscillates is provided so as to face each pressure generating chamber 4. The same effect can be obtained by applying a heating element capable of evaporating and vaporizing the liquid to be ejected to the recording head provided in each pressure generating chamber 4.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a liquid jet head of the present invention.

FIG. 2 is an assembled perspective view of the above recording head.

FIG. 3 is a plan view showing an example of a spacer.

4 (a) and 4 (b) are enlarged plan views showing a region (region A in FIG. 3) of the spacer, which is opposed to the opening of the jetted liquid guiding path of the head holder, and FIG. It is sectional drawing in the A line.

5 (a) and 5 (b) are plan views showing, in an enlarged manner, a region of another embodiment facing the opening of the jetted liquid guiding path of the head holder, and a cross section taken along line BB. It is a figure.

[Explanation of symbols]

3 Reservoir 4 Pressure Generation Chamber 5 Flow Path Unit 6
Head holder 7 Piezoelectric vibrator 10 Sealing plate 12
Injection liquid guide path 13 Opening 14 Nozzle plate
15 Spacer 16 Injection Liquid Inlet Port 18 Recess
18a Opening 19 Supporting part 20 Penetrating part

Claims (3)

[Claims] 1. A spacer having a plurality of pressure generating chambers formed in a row and having a reservoir communicating with the pressure generating chambers of each row via an injection liquid supply port, and a nozzle communicating with the pressure generating chambers. A flow path unit configured by stacking a nozzle plate having an opening, a pressure generation chamber, and a sealing plate for sealing the reservoir, and fixing the flow path unit to the reservoir. A head holder provided with an ejected liquid guide path for supplying the ejected liquid, wherein a recessed portion that opens toward the reservoir is formed in a region of the spacer where the flow passage is not formed, and in the region of the reservoir, and A liquid ejecting head, wherein a support portion having a full thickness is formed in a region facing the holder, and an opening of the liquid to be ejected guide path is fixed so as to face the recess. 2. The region where the recess is formed is located inside the region facing the opening of the liquid injection guide path and is the same as the reservoir in the region facing the opening of the liquid injection guide path. The liquid jet head according to claim 1, wherein a region having a depth of is present. 3. The spacer comprises a silicon single crystal substrate, and the reservoir is anisotropic full-etched,
The liquid jet head according to claim 1, wherein the recess is formed by anisotropic half etching.