JP2002086714A - Ink-jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording head whose substrate is effectively prevented from breaking by realizing an arrangement for letting out a stress. SOLUTION: There are provided a nozzle plate 20 where a plurality of nozzle openings 21 are formed in an array and a substrate member 10 adjacent to the nozzle plate 20. There are formed to the substrate member 10, a plurality of cavity parts 12 which communicate with nozzle openings 21 respectively, extend in a direction nearly orthogonal to a direction of the array of the nozzle openings 21 and are arranged to be parallel to each other in a direction nearly parallel to the array direction of the nozzle openings 21, and a common ink reservoir 13 communicating with each of the cavity parts. A fragile part 23 is formed to one side of the cavity part of one most lateral end of the plurality of cavity parts 12.

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 head, and more particularly to an ink jet recording head in which a substrate is effectively prevented from being broken.

[0002]

2. Description of the Related Art A conventional ink jet recording head is:
A plurality of nozzle openings arranged in a row, a plurality of cavities provided adjacent to each nozzle opening, and a reservoir communicating with each cavity are provided.

In general, a nozzle opening is formed in a nozzle plate, and a cavity and a reservoir are formed in a substrate member such as a silicon substrate. Then, the substrate member and the nozzle plate are joined by, for example, a thermosetting adhesive.

[0004] Further, a plurality of cavities are usually arranged in parallel, and as shown in FIG.
A dummy cavity 222 having the same shape as the cavity 212 is formed in parallel in two or three rows. The dummy cavity 222 is provided to stabilize the ink ejection characteristics in consideration of the fact that the ink supply from the end of the reservoir 213 is likely to vary.

[0005]

Usually, since the substrate member and the nozzle plate are manufactured from different materials, the substrate member and the nozzle plate have different coefficients of linear expansion. As a result, stress may be generated at a joint portion between the substrate member and the nozzle plate due to heating (up to about 200 ° C.) at the time of assembling and mounting the printhead or a rise in temperature at the time of using the printhead. . Such stress caused by heating or temperature rise can cause cracking of the substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an ink jet recording head which realizes a configuration for releasing stress and effectively prevents breakage of a substrate. I do.

[0007]

According to the present invention, there is provided a nozzle plate in which a plurality of nozzle openings are formed in rows, a substrate member adjacent to the nozzle plate, and a substrate member, each of which communicates with each nozzle opening. And a plurality of cavities extending in a direction substantially orthogonal to the row direction of the nozzle openings, and substantially parallel to each other in the row direction of the nozzle openings, and a common ink formed in the substrate member and communicating with each cavity section. An ink jet recording head comprising: a reservoir; and a fragile portion formed in a substrate member and further provided on one side of an endmost cavity on one side of the plurality of cavities. .

According to the present invention, by actively providing the fragile portion to the substrate member, the stress that can be generated at the end of the nozzle row can be effectively released, and the destruction of the substrate can be effectively prevented. can do. Further, when excessive stress is applied, the fragile portion of the substrate member is destroyed first, so that other portions, for example, the dummy cavity portion and the cavity portion are prevented from being broken, and leakage of ink and the like can be prevented. .

Alternatively, the present invention provides a nozzle plate in which a plurality of nozzle openings are formed in two rows of a first row and a second row which are substantially parallel and adjacent to each other, a substrate member adjacent to the nozzle plate, and a substrate member. The first cavity group is formed and communicates with each of the nozzle openings forming the first row and extends in a direction substantially orthogonal to the row direction of the nozzle openings. A plurality of first cavities, a first common ink reservoir formed in the substrate member, communicating with one longitudinal end of each first cavity portion, and a first common ink reservoir formed in the substrate member, each of which is formed in a second row. And extending in a direction substantially orthogonal to the row direction of the nozzle openings, and substantially parallel to each other in the row direction of the nozzle openings to be substantially parallel to and adjacent to the first cavity group. A plurality of second cavities forming a group of cavities, a second common ink reservoir formed in the substrate member and communicating with the other longitudinal end of each second cavity portion, and a plurality of second cavities formed in the substrate member; An ink jet recording head comprising: a fragile portion further provided on one side of the endmost one of the first cavity portion and the second cavity portion.

In this case, it is preferable that the fragile portion is provided only in a portion from the one side area in the nozzle row direction to the first common ink reservoir to the one side area in the nozzle row direction to the second common ink reservoir. . That is, it is preferable that the fragile portion is not formed at the edge of the substrate member. This is to secure the rigidity of the substrate member.
On the other hand, it is preferable that the fragile portion is more easily broken than the partition portion that partitions the adjacent first cavity portion and second cavity portion. The fragile part breaks first when applying excessive stress, preventing breakage of other parts,
This is because leakage of the ink and the like can be prevented.

It is preferable that a dummy cavity is formed between the endmost cavity on one side and the fragile part in order to adjust the ink discharge characteristics.

In the substrate member, a positioning hole may be formed on one side of the fragile portion for positioning or the like at the time of assembling the recording head.

As a specific mode of the fragile portion, for example,
A plurality of, for example, slit-shaped through holes can be formed in a perforated shape. Alternatively, a plurality of, for example, slit-shaped thin portions may be formed in a perforated shape.

Preferably, the surface of the substrate member opposite to the nozzle plate is provided with a pressure variation device for varying the pressure of ink in each cavity, and the pressure variation device together with a partial area of the substrate member. And a sealing member for defining a surrounding sealing space, and the fragile portion is formed in a region outside a partial region of the substrate member that defines the sealing space. In this case, the breakage of the fragile portion does not affect the sealing space.

[0015] The fragile portion can usually be formed parallel to the cavity portion.

More specifically, the substrate member has a plane orientation (11
In the case of the silicon single crystal substrate of 0), the fragile portion is
It may be formed in a first (111) plane perpendicular to the (110) plane.

However, the fragile portion is approximately 7 mm in the first (111) plane perpendicular to the (110) plane and the first (111) plane.
It may be formed in a second (111) plane that forms an angle of 0 degrees and forms an angle of about 35 degrees with the (110) plane.

[0018]

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

FIG. 1 is an exploded perspective view of a first embodiment of an ink jet recording head according to the present invention, and FIG.
FIG. 2 is a plan view and a cross-sectional view of FIG. FIG. 3 is a plan view of the entire flow path substrate (substrate member) of the present embodiment.

The flow path forming substrate 10 shown in FIG. 1 and FIG.
In the present embodiment, it is composed of a silicon single crystal substrate having a plane orientation (110). As the flow path forming substrate 10, usually, 15
Thickness of about 0 to 300 μm is used, preferably about 180 to 280 μm, more preferably 220 μm.
Thicknesses of the order of magnitude are preferred. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent cavity portions.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with an elastic film 50 having a thickness of 1 to 2 μm and made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on a silicon single crystal substrate,
Cavities (pressure generating chambers) 12 partitioned by a plurality of partition walls 11 are arranged side by side in the width direction, and on the outside in the longitudinal direction, a common part of each cavity 12 communicates with a reservoir of a reservoir forming substrate described later. Reservoir 1 which becomes ink chamber
A reservoir portion 13 that forms a part of the cavity portion 00 is formed and communicates with one longitudinal end portion of each cavity portion 12 via an ink supply path 14. The ink supply path 14 is also partitioned by the partition 11 like the cavity 12.

Here, in the anisotropic etching, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, it is gradually eroded, and the first (111) plane perpendicular to the (110) plane and the first (111) plane A second (1) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the (110) plane.
11) plane, and the etching rate of the (111) plane is about 1/1 compared to the etching rate of the (110) plane.
This is performed using the property of being 80.
By such anisotropic etching, two first (11
Precision processing can be performed based on the depth processing of a parallelogram formed by the 1) plane and two oblique second (111) planes, and the cavities 12 can be arranged at a high density. .

In the illustrated example, the long side of each cavity 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The cavity 12 is formed by etching until it reaches the elastic film 50 substantially through the flow path forming substrate 10. Here, the elastic film 50
Is extremely small in the amount attacked by an alkaline solution for etching a silicon single crystal substrate. Each cavity 1
Each of the ink supply passages 14 communicating with one end of the ink passage 2 is formed shallower than the cavity portion 12, and maintains a constant flow resistance of the ink flowing into the cavity portion 12. That is, the ink supply path 14 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. Note that the half etching is performed by adjusting the etching time.

On the opening side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle opening 21 communicating therewith on the side opposite to the ink supply path 14 of each cavity 12 is formed.
Are fixed via an adhesive or a heat-sealing film. The thickness of the nozzle plate 20 is, for example, 0.0
5 to 0.2 mm, made of non-rusting steel. Nozzle plate 2
Numeral 0 completely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force.

Here, the size of the cavity portion 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 21 for ejecting the ink droplet are optimal according to the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Be transformed into

On the other hand, a lower electrode film 60 having a thickness of, for example, about 0.2 μm and a piezoelectric material having a thickness of, for example, about 1 μm are formed on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10. Layer 70
And an upper electrode film 80 having a thickness of about 0.1 μm, for example, are laminated to form the piezoelectric element 300. here,
The piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each cavity 12. The piezoelectric active portion 3 is constituted by one of the patterned electrodes and the piezoelectric layer 70, and generates a piezoelectric strain by applying a voltage to both electrodes.
Twenty. In this embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300, and the upper electrode film 80 is used as the piezoelectric element 30.
Although the number of the individual electrodes is 0, there is no problem even if the relationship is reversed for convenience of the drive circuit and wiring. In any case, the piezoelectric active portion is formed for each cavity portion. The piezoelectric element 300 and the piezoelectric element 30
A combination of the vibration plate and the vibration plate, which is displaced by the drive of 0, is referred to as a piezoelectric actuator (pressure fluctuation unit).

In this embodiment, the lead electrode 90
Extends from the vicinity of one end in the longitudinal direction of the upper electrode film 80 of the piezoelectric element 300 to a region facing the peripheral wall of the cavity 12, and the tip is located outside the joining member 40 described later. .

The piezoelectric element 300 of the flow path forming substrate 10
The portion corresponding to the reservoir section 13 on the side of
The reservoir forming substrate 30 having the reservoir portion 31 constituting at least a part of the “0” is joined. Reservoir part 3
1 is formed so as to penetrate the reservoir forming substrate 30 in the thickness direction and extend in the width direction (side-by-side direction) of the cavity portion 12. Then, as described above, the flow path forming substrate 1
0 reservoir portion 13 and through hole 5 formed in elastic film 50
1, the reservoir 100 is formed as a common ink chamber of each cavity 12.

As the reservoir forming substrate 30, glass,
It is preferable to use a material that is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10 such as a ceramic material. In the present embodiment,
It is formed using a silicon single crystal substrate of the same material as the flow path forming substrate 10. Thereby, both can be reliably bonded by bonding at a high temperature using a thermosetting adhesive.

Further, a sealing plate 35 made of a metal 35b such as stainless steel (SUS) and a flexible film 35a is joined to the reservoir forming substrate 30, and the reservoir 100 is sealed. . In addition, the sealing plate 35 outside the substantially central portion in the longitudinal direction of the reservoir 100 includes:
An ink inlet 36 and an ink inlet 32 for supplying ink to the reservoir 100 are formed (see FIG. 2).

In a region corresponding to the piezoelectric element 300, a piezoelectric element surrounding portion 41 capable of sealing the space with a space secured so as not to hinder the movement of the piezoelectric element 300.
Is joined.
The joining member 40 is provided with a communication hole 42 for communicating the piezoelectric element surrounding portion 41 with the outside.

As shown in FIG. 1, the joining member 40 of the present embodiment is constituted by an integral member that is continuous with the reservoir forming substrate 30. That is, the penetrating reservoir portion 31 is formed on a single substrate member, and the thin (half-etched) piezoelectric element surrounding portion 41 is formed. However, the joining member 40 and the reservoir forming substrate 30 may be configured as independent substrate members.

A driving circuit 110 such as a semiconductor integrated circuit (IC) for driving the piezoelectric element 300 is mounted on the joining member 40. The driving circuit 120 is composed of a bonding wire. And is electrically connected to the distal end of the lead electrode 90 extending therefrom.

The piezoelectric element surrounding portion 41 of the joining member 40
The inside is filled with a drying fluid such as an inert gas through the communication hole 42, and the communication hole 42 is sealed by a sealing member 45 made of resin. Preferably, the inside of the piezoelectric element surrounding portion 41 is sealed at a pressure lower than the atmospheric pressure. Thus, the piezoelectric element 300 is securely sealed in the dry fluid atmosphere in the piezoelectric element surrounding portion 41 and is shut off from the external environment.

For further details regarding the above-mentioned type of ink jet recording head, see Japanese Patent Application No. 2000-84772.
No. The contents described in Japanese Patent Application No. 2000-84772 are incorporated herein by reference. The pitch of the nozzle openings is, for example, 180
In the case of dpi, it is about 141 μm.

As shown in FIGS. 1 and 2, the plurality of nozzle openings 21 of the present embodiment are provided on the nozzle plate 20 in a right row (first row) and a left row (second row) substantially parallel and adjacent to each other. Are formed in two rows. In the present embodiment, the nozzle openings 21a in the left column and the nozzle openings 21b in the right column are staggered, but other arrangements may be adopted.

The plurality of cavities 12 of the present embodiment
Is formed on the flow path forming substrate (substrate member) 10,
Each of the first cavity groups A communicates with each of the nozzle openings 21a forming the left row and extends in a direction substantially perpendicular to the row direction of the nozzle openings 21a. Are formed (see FIG. 3).

The plurality of cavities 12 communicate with the respective nozzle openings 21b forming the right row and extend in a direction substantially perpendicular to the row direction of the nozzle openings 21b. It has a plurality of second cavity portions 12b that are substantially juxtaposed in the column direction to form a second cavity group B substantially parallel to and adjacent to the first cavity group A (see FIG. 3).

In the flow path forming member 10, a first common ink reservoir 13a communicating with each first cavity 12a and a second common ink reservoir 13b communicating with each second cavity 12b are formed. ing.

Further, each of the flow path forming members 10 extends in a direction substantially orthogonal to the row direction of the nozzle openings 21a.
Further one side (upper side) of the end of one side (upper side in FIG. 3) of the plurality of first cavity sections 12a.
A plurality of nozzles arranged in parallel in the row direction of the nozzle openings 21a substantially in parallel with each other and in parallel with each other,
A first dummy cavity portion 22a in a row is formed.

Further, each of the flow path forming members 10 extends in a direction substantially orthogonal to the row direction of the nozzle openings 21b.
One further side (upper side) of the endmost side (upper side in FIG. 3) of one side of the plurality of second cavity sections 12b.
A plurality of nozzles arranged in parallel in the row direction of the nozzle openings 21b substantially in parallel with each other and in parallel with each other,
A second dummy cavity portion 22b in a row is formed.

The length of the first dummy cavity portion 22a is
The length is the same as the length of the first cavity portion 12a.

Similarly, the length of the second dummy cavity 22b is the same as the length of the second cavity 12b.

In this embodiment, the first cavity 12
a and the second cavity portion 12b have the same length, and therefore, the first dummy cavity portion 22a and the second dummy cavity portion 22b have the same length.

The other end in the nozzle row direction is provided with a dummy cavity symmetrically with the one end.

That is, in the case of the present embodiment, each of the flow path forming substrates 10 extends in a direction substantially orthogonal to the row direction of the nozzle openings 21a, and the other of the plurality of first cavities 12a. On the other side (lower side) of the cavity part at the sidemost end (lower side in FIG. 3), a plurality of juxtaposed in the row direction of the nozzle openings 21a substantially parallel to each other and parallel to each other, in this case 3 A row of opposing first dummy cavity portions 22a 'are formed.

Similarly, each of the flow path forming substrates 10 extends in a direction substantially perpendicular to the row direction of the nozzle openings 21b, and is the other end of the plurality of second cavity portions 12b (FIG. 3). On the other side (lower side) of the cavity section
A plurality of nozzles arranged in parallel in the row direction of the nozzle openings 21b substantially in parallel with each other and in parallel with each other,
A row of opposing second dummy cavities 22b 'is formed.

The opposed first dummy cavity portion 22a '
The length of the first dummy cavity 22a is the same as that of the second dummy cavity 22b, and the length of the opposing second dummy cavity 22b 'is the same as that of the second dummy cavity 22b.

In the present embodiment, each first cavity 1
2a communicates with the nozzle row 21a in the left column at one end (right side) in the longitudinal direction (left-right direction in FIG. 3), and the first common ink reservoir 13a at the other end (left side) in the longitudinal direction. Is in communication with Similarly, each second cavity portion 12b is
The left end in the longitudinal direction communicates with the nozzle openings 21b in the right row, and the right end in the longitudinal direction communicates with the second common ink reservoir 13b.

In this embodiment, each first dummy cavity 22a and each opposing first dummy cavity 2a
2a 'communicates with the first common ink reservoir 13a at the left end in the longitudinal direction, and each second dummy cavity 2
2b and each opposing second dummy cavity portion 22b 'communicate with the second common ink reservoir 13b at the right end in the longitudinal direction.

Then, each first dummy cavity portion 22a
Both ends of each opposing first dummy cavity 22a 'and both ends of each first cavity 12a are linearly aligned in the row direction of the nozzle openings 21a.

Similarly, each second dummy cavity portion 22b
Both ends of each opposing second dummy cavity 22b 'and both ends of each second cavity 12b are linearly aligned in the row direction of the nozzle openings 21b.

Now, the flow path forming substrate 10 of the present embodiment
As shown in FIG. 3, the fragile portion 23 is further provided on one side (upper side in FIG. 3) of the end of the plurality of first dummy cavity portions 22a and second dummy cavity portions 22b. Are formed.

In this case, the fragile portion 23 is moved from one side of the first common ink reservoir 13a in the nozzle row direction to the second common ink reservoir 13a.
It is formed up to one side area in the nozzle row direction with respect to the common ink reservoir 13b. That is, the flow path forming substrate 10
The fragile portion 23 is not formed in the left and right edge regions E of FIG.

The flow path forming member 10 has a positioning hole 24 formed on one side of the fragile portion 23 for assembling and the like.

The fragile portions 23 and the positioning holes 24 are provided symmetrically at both ends in the nozzle row direction. That is, as shown in FIG.
A fragile portion 23 ′ is formed on the other side (lower side in FIG. 3) of the a ′ and the opposing second dummy cavity portion 22 b ′, on the other side.

The fragile portion 23 'also extends from the other side of the first common ink reservoir 13a in the nozzle row direction to the other side of the second common ink reservoir 13b in the nozzle row direction.
Is formed. That is, the fragile portions 23 'are not formed in the left and right edge portions F of the flow path forming substrate 10.

Then, on the other side of the fragile portion 23 ',
A positioning hole 24 'for assembly or the like is formed.

In the present embodiment, the fragile parts 23, 23 '
Are formed parallel to the cavities 12a and 12b. As a result, the fragile parts 23 and 23 ′ are (11
It is formed in the first (111) plane perpendicular to the (0) plane. As described above, by forming the fragile portion along the first (111) plane, the strength of the fragile portion is further reduced.

The fragile portions 23 and 23 'have a plurality of slit-shaped through holes formed in a perforated shape. Alternatively, it has a plurality of slit-shaped thin portions formed in a perforated shape. These through-holes or thin-walled portions are the first portions where the strengths of the fragile portions 23, 23 'are adjacent.
It is formed with a void density that is weaker than the partition 11 that partitions the cavity 12a and the second cavity 12b, and that the fragile portions 23 and 23 ′ are more easily broken than the partition 11. The fragile portions 23, 23 'can be formed by anisotropic etching, like the cavities 12a, 12b. That is, a through hole can be formed by full etching, and a thin portion can be formed by half etching.

Here, the fragile portions 23, 23 'and the joining member 4
One relationship with 0 (sealing member) will be described with reference to FIG. FIG. 4 is a schematic sectional view in the nozzle row direction of FIG.

As shown in FIG. 4, the fragile portions 23, 23 '
Is formed outside the region of the flow path forming substrate 10 facing the piezoelectric element surrounding portion 41 of the joining member 40. Thereby, breakage of the fragile parts 23 and 23 ′
The sealing state inside the piezoelectric element surrounding portion 41 is not affected.

According to the present embodiment as described above, the provision of the dummy cavities 22a, 22b, 22a 'and 22b' makes it possible to stabilize the ink discharge characteristics of the recording head.

On the other hand, the fragile portions 23 and 23 ′ are positively provided in the flow path forming member 10, so that stress that may be generated at both ends of the nozzle row during head assembly or head mounting can be effectively released. Can be. Further, when excessive stress is applied, the weak portions 23, 2
Since 3 ′ is destroyed first, the other portions, for example, the dummy cavities 22a and 22b, are prevented from being destroyed, and the leakage of ink is prevented.

Next, an ink jet recording head according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a plan view of the entire flow path forming substrate (substrate member) in the ink jet recording head according to the second embodiment.

As shown in FIG. 5, the fragile portions 23 and 23 'of the present embodiment include portions 23a and 23a' parallel to the cavities 12a and 12b, and cavities 12a and 23 '.
It has portions 23b and 23b 'inclined with respect to 12b. In this case, the fragile parts 23 and 23 'are (110)
The first (111) plane (parallel portion) perpendicular to the plane and the first
At an angle of about 70 degrees with the (111) plane of (110)
It is formed in the second (111) plane (inclined portion) forming an angle of about 35 degrees with the plane.

The other structure is substantially the same as the structure of the ink jet recording head according to the first embodiment shown in FIGS. In the second embodiment, FIG.
The same parts as those in the first embodiment shown in FIG. 4 to FIG. 4 are denoted by the same reference numerals, and detailed description is omitted.

Also in this embodiment, the first (11)
By forming the fragile portion along the 1) plane and the second (111) plane, the strength of the fragile section is actively reduced.

As in the present embodiment, the first (111)
Vulnerable part 2 using not only surface but also second (111) surface
By forming 3, 23 ', the fragile portions 23, 23'
Can be expanded to a mode other than the mode parallel to the cavities 12a and 12b, and the design flexibility is remarkably improved.

In each of the above embodiments, the first
The end positions of the common ink reservoir 13a and the second common ink reservoir 13b are aligned with the dummy cavities at both ends in the nozzle row direction, but are not limited thereto, and may be appropriately changed so as to be favorable for ink ejection characteristics. Can be done.

In addition, the number and arrangement pitch of the nozzle openings, the shape of each reservoir, the arrangement of the cavities, the number of dummy cavities, and the like are suitable for the stress characteristics and ink discharge characteristics required for the recording head. In addition, it can be appropriately selected within the scope of each claim in the claims so as to be more suitable for manufacturing convenience.

A feature of the present invention resides in that a fragile portion is positively provided on a substrate member. Therefore, other components of the recording head, for example, a configuration (piezoelectric element) for generating the ink ejection pressure are not limited by the above-described embodiment.

[0074]

As described above, according to the present invention, the stress that may be generated at the end of the nozzle row can be effectively released by providing the fragile portion on the substrate member positively. Can be effectively prevented from being destroyed. Further, when excessive stress is applied, the fragile portion of the substrate member is destroyed first, so that other portions, for example, the dummy cavity portion and the cavity portion are prevented from being broken, and leakage of ink and the like can be prevented. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment of an ink jet recording head according to the present invention.

FIG. 2 is a plan view and a cross-sectional view of FIG.

FIG. 3 is an overall plan view of a flow path forming member of the first embodiment of the ink jet recording head according to the present invention.

FIG. 4 is a sectional view of a flow path forming member and a joining member in a nozzle row direction.

FIG. 5 is an overall plan view of a flow path forming member of a second embodiment of the ink jet recording head according to the present invention.

FIG. 6 is a schematic diagram showing a positional relationship between a conventional cavity portion and a dummy cavity portion.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 11 partition wall 12 cavity section 12a first cavity section 12b second cavity section 13 reservoir section 13a first common ink reservoir section 13b second common ink reservoir section 14 ink supply path 20 nozzle plate 21, 21a, 21b nozzle Opening 22 Dummy cavity part 22a First dummy cavity part 22b Second dummy cavity part 22a 'Opposite first dummy cavity part 22b' Opposite second dummy cavity part 23 Weak part 24 Positioning hole 30 Reservoir forming substrate 32 Ink introduction path 35 Sealing Plate 36 Ink inlet 40 Joining member 41 Piezoelectric element surrounding part 45 Sealing member 50 Elastic film 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 100 Reservoir 110 Drive circuit 120 Drive wiring 300 Piezoelectric element

Claims (12)

[Claims] 1. A nozzle plate having a plurality of nozzle openings formed in a row, a substrate member adjacent to the nozzle plate, a substrate member formed on the substrate member, each communicating with each nozzle opening, and in a row direction of the nozzle openings. A plurality of cavities extending in a direction substantially orthogonal to each other and arranged substantially parallel to each other in a row direction of the nozzle openings; a common ink reservoir formed in the substrate member, communicating with each cavity portion; and a plurality of cavities formed in the substrate member. An ink-jet recording head, further comprising a fragile portion provided on one side of an endmost cavity on one side of the plurality of cavities. 2. A nozzle plate having a plurality of nozzle openings formed in two rows of a first row and a second row, which are substantially parallel and adjacent to each other, a substrate member adjacent to the nozzle plate, and a plurality of nozzle openings formed on the substrate member. Are communicated with the respective nozzle openings forming the first row and extend in a direction substantially perpendicular to the row direction of the nozzle openings, and are arranged substantially parallel to each other in the row direction of the nozzle openings to form a first cavity group. A first common ink reservoir formed in the substrate member and communicating with one longitudinal end of each first cavity portion; and a first common ink reservoir formed in the substrate member, each forming a second row. A second cavity group which is communicated with the nozzle openings and extends in a direction substantially perpendicular to the row direction of the nozzle openings and is substantially parallel to each other and substantially juxtaposed in the row direction of the nozzle openings to form a second cavity group substantially parallel to and adjacent to the first cavity group. A plurality of second cavities, a second common ink reservoir formed in the substrate member and communicating with the other longitudinal end of each second cavity portion, and a plurality of the first cavity portions formed in the substrate member And a fragile portion provided on one side of the one endmost cavity portion of the second cavity portion. 3. The device according to claim 2, wherein the fragile portion is provided from a region on one side of the first common ink reservoir in the nozzle row direction to a region on one side of the second common ink reservoir in the nozzle line direction. Inkjet recording head. 4. The method according to claim 1, wherein the fragile portion is apt to be broken more easily than a partition portion that separates the adjacent first cavity portion and second cavity portion. The ink jet recording head according to the above. 5. The ink jet recording head according to claim 1, wherein a dummy cavity is formed between the one endmost cavity and the weakened part. 6. The ink jet recording head according to claim 1, wherein the substrate member has a positioning hole formed on one side of the fragile portion. 7. The ink jet recording head according to claim 1, wherein the fragile portion has a plurality of perforations formed in perforations. 8. The ink jet recording head according to claim 1, wherein the fragile portion has a plurality of thin portions formed in a perforated shape. 9. A pressure change means for changing the pressure of ink in each cavity on a surface of the substrate member opposite to the nozzle plate, and the pressure change means is surrounded together with a partial region of the substrate member. A sealing member for partitioning the sealing space, wherein the fragile portion is formed in a region outside a partial region of the substrate member that partitions the sealing space. 9. The ink jet recording head according to any one of 1 to 8. 10. The ink jet recording head according to claim 1, wherein the fragile portion is formed parallel to the cavity. 11. The substrate member is made of a silicon single crystal substrate having a plane orientation of (110), and the fragile portion is formed in a first (111) plane perpendicular to the (110) plane. The inkjet recording head according to claim 10. 12. The substrate member is composed of a silicon single crystal substrate having a plane orientation of (110), and the fragile portion is formed in a first (111) plane and a first (111) plane perpendicular to the (110) plane. A second (111) forming an angle of about 70 degrees and forming an angle of about 35 degrees with the (110) plane;
10. The light emitting device according to claim 1, wherein the light emitting device is formed in a plane.
The inkjet recording head according to any one of the above.