JP2003127360A - Ink jet recording head and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head in which pressure-generating chambers are arranged with high-density, and defective discharging is prevented, and also to provide an ink jet recording device having the head. SOLUTION: The ink jet recoding head is provided with nozzle plates 20 each having a nozzle opening 21, a flow passage forming substrate 10 in which pressure generating chambers 12 communicating with the nozzle opening 21 are partitioned, and piezoelectric elements 300 arranged in an area corresponding to the pressure generating chambers 12 in the flow passage forming substrate 10 through diaphragms and imparting a pressure to discharge ink to the inside of the pressure generating chambers 12. The flow passage forming substrate 10 and the nozzle plates 20 are bonded through an adhesive agent 25. At least one groove 15 which communicates with an end of each pressure generating chamber 12 on the nozzle opening 21 side in longitudinal direction of the chamber and has the adhesive agent get in the groove is provided on a bonding surface between the flow passage forming substrate 10 and the nozzle plate 20. As a result, clogging of the nozzle opening 21 with the adhesive agent 25 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a vibrating plate which constitutes a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets, and a piezoelectric element is provided through the vibrating plate to displace the piezoelectric element. The present invention relates to an ink jet type recording head and an ink jet type recording apparatus for ejecting ink droplets.

[0002]

2. Description of the Related Art A part of a pressure generating chamber that communicates with a nozzle opening for ejecting ink droplets is composed of a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber to eject it from the nozzle opening. Two types of inkjet recording heads that eject ink droplets have been put into practical use: one that uses a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of a piezoelectric element, and one that uses a flexural vibration mode piezoelectric actuator. ing.

The former allows the volume of the pressure generating chamber to be changed by bringing the end face of the piezoelectric element into contact with the vibrating plate, and a head suitable for high-density printing can be manufactured. There is a problem in that the manufacturing process is complicated because a difficult process of matching the array pitch of the openings and cutting into comb teeth or a work of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required.

On the other hand, in the latter, the piezoelectric element can be formed on the vibration plate by a relatively simple process of sticking a green sheet of a piezoelectric material in conformity with the shape of the pressure generating chamber and firing it. However, due to the use of flexural vibration, a certain area is required, and there is a problem that high-density arrangement is difficult.

On the other hand, in order to eliminate the disadvantage of the latter recording head, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique as disclosed in Japanese Patent Laid-Open No. 5-286131. It has been proposed that the piezoelectric material layer is cut into a shape corresponding to the pressure generating chamber by a lithographic method and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

[0006]

As described above, in the ink jet recording head, in general, a nozzle in which a plurality of nozzle openings for ejecting ink droplets are formed on the flow path forming substrate in which the pressure generating chamber is formed. It has a structure in which the plates are joined by an adhesive.

For this reason, when the pressure generating chambers (piezoelectric elements) are arranged at a high density as described above, the adhesive area between the nozzle plate and the flow path forming substrate becomes small, and waste adhesive is excessively generated in the pressure generating chambers. There is a risk that it will flow out to. Then, the nozzle opening is closed by the adhesive flowing out into the pressure generating chamber,
There is a problem that defective ejection occurs.

In view of such circumstances, it is an object of the present invention to provide an ink jet type recording head and an ink jet type recording apparatus in which pressure generating chambers can be arranged at a high density and ejection defects can be prevented.

[0009]

A first aspect of the present invention for solving the above problems is a nozzle plate having a nozzle opening, and a flow path forming substrate defining a pressure generating chamber communicating with the nozzle opening. An inkjet recording head comprising: a piezoelectric element which is provided in a region corresponding to the pressure generating chamber of the flow path forming substrate via a vibration plate and applies a pressure for ejecting ink into the pressure generating chamber, The flow path forming substrate and the nozzle plate are bonded via an adhesive, and a longitudinal end portion of each pressure generating chamber on the side of communication with the nozzle opening, on the bonding surface of the flow path forming substrate with the nozzle plate. The ink jet recording head is characterized by being provided with at least one groove portion which is communicated with the above and into which the adhesive has entered.

In the first aspect, when the flow path forming substrate and the nozzle plate are bonded together, useless adhesive flows into the groove. As a result, the amount of adhesive flowing out into the pressure generating chamber can be significantly suppressed, and defects such as clogging of nozzle openings can be prevented.

According to a second aspect of the present invention, in the first aspect, the groove has a width of less than 20 μm and a depth of 5 μm.
The inkjet recording head is characterized by being smaller than μm.

In the second aspect, since the groove is made to have a predetermined size and the groove is filled with the adhesive agent for bonding the flow path forming substrate and the nozzle plate, air bubbles and the like do not remain in the groove. Deterioration of ink ejection characteristics is prevented.

A third aspect of the present invention is the ink jet recording according to the first or second aspect, characterized in that the groove portion is provided so as to communicate with a substantially central portion in the width direction of the pressure generating chamber. On the head.

In the third aspect, wasteful adhesive easily flows into the groove portion, and it is possible to effectively prevent the adhesive from flowing out into the pressure generating chamber.

A fourth aspect of the present invention is the ink jet system according to the first or second aspect, characterized in that the groove portion is provided so as to communicate with at least both widthwise end portions of the pressure generating chamber. It is on the recording head.

In the fourth aspect, since the waste adhesive is surely flown into the groove, it is possible to effectively prevent the adhesive from flowing out into the pressure generating chamber.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the groove portion is filled with an adhesive agent for adhering the flow path forming substrate and the nozzle plate. The inkjet recording head is characterized by

In the fifth aspect, it is possible to prevent the occurrence of ejection failure due to the accumulation of bubbles and the like in the groove.

A sixth aspect of the present invention is any one of the first to fifth aspects, wherein the arrangement density of the pressure generating chambers is 200d.
The inkjet recording head is characterized by having a pi or more.

In the sixth aspect, since the pressure generating chambers are arranged at a high density, the adhesive easily flows out into the pressure generating chamber, but the groove is provided to effectively prevent the adhesive from flowing out. You can

In a seventh aspect of the present invention according to any one of the first to sixth aspects, the flow path forming substrate is made of a silicon single crystal substrate, and the pressure generating chamber and the groove are formed by anisotropic etching. The inkjet recording head is characterized in that

In the seventh aspect, the pressure generating chamber and the groove can be formed with relatively high accuracy.

According to an eighth aspect of the present invention, in the ink jet recording head according to the seventh aspect, the flow path forming substrate is made of a silicon single crystal substrate whose main surface is a (110) plane. is there.

In the eighth aspect, the pressure generating chamber and the groove can be formed with relatively high accuracy. Further, when a silicon single crystal substrate having a (110) plane as a main surface is used, the nozzle opening is particularly likely to be clogged with an adhesive, but the provision of the groove portion can surely prevent the nozzle opening from being clogged. .

A ninth aspect of the present invention is the ink jet recording head according to the seventh or eighth aspect, characterized in that the pressure generating chamber and the groove are formed in separate steps.

In the ninth aspect, the pressure generating chamber and the groove can be formed with higher accuracy.

A tenth aspect of the present invention is an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to ninth aspects.

In the tenth aspect, it is possible to realize the ink jet recording apparatus which can prevent the ejection failure of the head and improve the reliability.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a sectional view of FIG.

As shown in the figure, the flow path forming substrate 10 is a silicon single crystal substrate having a plane orientation (110) in this embodiment. One surface of the flow path forming substrate 10 is an opening surface, and an elastic film 50 having a thickness of 1 to 2 μm made of silicon dioxide formed in advance by thermal oxidation is formed on the other surface.

In this flow path forming substrate 10, pressure generating chambers 12 partitioned by a plurality of partition walls 11 are arranged side by side in the width direction by anisotropically etching a silicon single crystal substrate. The arrangement density of the pressure generating chambers 12 is preferably 200 or more per inch, that is, 200 dpi or more. For example, in the present embodiment, it is 360.
It is dpi. Further, on the outside in the longitudinal direction, there is formed a communication portion 13 that communicates with a reservoir portion 31 of a reservoir forming substrate 30 described later and constitutes a part of the reservoir 100 that serves as a common ink chamber for each pressure generating chamber 12. Each pressure generation chamber 1
The two longitudinal ends are communicated with each other via the ink supply paths 14.

Further, the flow path forming substrate 10 is communicated with a longitudinal end portion of the pressure generating chamber 12 which is in communication with the nozzle opening 21, that is, an end portion of the pressure generating chamber 12 opposite to the communication portion 13. At least one groove portion 15 is formed in each pressure generating chamber 1
It is provided corresponding to each of the two. For example, in the present embodiment, one groove portion 15 that communicates with the substantially central portion in the width direction of the pressure generating chamber 12 is provided corresponding to each pressure generating chamber 12.

Here, a nozzle plate 20 described later is adhered to the opening surface side of the flow path forming substrate 10 with an adhesive 25. The groove portion 15 is formed in the flow path forming substrate 1
When the No. 0 and the nozzle plate 20 are bonded to each other with the adhesive 25, the unnecessary adhesive 25 is prevented from flowing out into the pressure generating chamber 12. That is, it is possible to prevent the adhesive 25 from flowing out into the pressure generating chamber 12 by the useless adhesive flowing into the groove 15. Therefore, the adhesive 25 that joins the flow path forming substrate 10 and the nozzle plate 20 flows into all the groove portions 15.

It is preferable that the adhesive 25 is completely filled in the groove 15. As a result, when the pressure generating chamber 12 is filled with ink and ink droplets are ejected, it is possible to prevent ejection failure from occurring.
If the groove 15 has a space without being filled with the adhesive 25, bubbles remain in this space when the pressure generating chamber 12 is filled with ink, and the bubbles are mixed in the ink to cause ejection failure. There is a risk of

The size of the groove 15 is such that the adhesive 25 for bonding the flow path forming substrate 10 and the nozzle plate 20 together.
The width of the groove 15 is preferably smaller than 20 μm, and the depth is 5 μm.
It is preferably smaller than m. Thereby, the groove 15
The adhesive 25 is completely filled in the inside, and it is possible to effectively prevent wasteful adhesive from flowing out into the pressure generating chamber 12.

Incidentally, such a groove portion 15 is also formed in the pressure generating chamber 1
It is formed by anisotropically etching the flow path forming substrate 10 in the same manner as 2 and the like.

Here, the anisotropic etching is performed by utilizing the difference in the etching rate of the silicon single crystal substrate. For example, in this embodiment, the silicon single crystal substrate is set to K.
When it is dipped in an alkaline solution such as OH, it is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane
Forms an angle of about 70 degrees with the (111) plane of
A second (111) plane that makes an angle of about 35 degrees with the (0) plane appears, and the etching rate of the (111) plane is about 1/180 of the etching rate of the (110) plane. Is done using. By such anisotropic etching, it is possible to perform precision machining based on the depth machining of the parallelogram shape formed by the two first (111) planes and the two diagonal second (111) planes. The pressure generating chambers 12 can be arranged in high density.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided in the flow path forming substrate 1
It is formed by etching through almost 0 to reach the elastic film 50. Here, the elastic film 50 is
The amount of the alkaline solution that etches the silicon single crystal substrate is extremely small. Further, each ink supply passage 14 communicating with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and keeps the flow resistance of the ink flowing into the pressure generation chamber 12 constant. That is, the ink supply path 14 is formed by etching the silicon single crystal substrate halfway in the thickness direction (half etching). Further, the groove portion 15 is also formed by half-etching the silicon single crystal substrate similarly to the ink supply passage 14. The half etching is performed by adjusting the etching time.

As for the thickness of the flow path forming substrate 10, an optimum thickness may be selected in accordance with the array density of the pressure generating chambers 12. For example, if the array density is about 180 dpi, the flow path forming substrate 10 is formed. The thickness of the substrate 10 may be about 220 μm, but the pressure generating chamber 12 may not be formed in the same manner as in the present embodiment.
When the flow passage forming substrate 10 is arranged in a relatively high density of 0 dpi or more, it is preferable that the thickness of the flow path forming substrate 10 is 100 μm or less. This is because the array density can be increased while maintaining the rigidity of the partition walls 11 between the adjacent pressure generating chambers 12.

Further, on the opening side of the flow path forming substrate 10,
As described above, the ink supply passage 14 of each pressure generating chamber 12
A nozzle plate 20 having a nozzle opening 21 that communicates with the opposite side thereof is joined by an adhesive 25. The nozzle plate 20 has a thickness of, for example, 0.
It is made of glass ceramics having a linear expansion coefficient of 1 to 1 mm and a linear expansion coefficient of 300 ° C. or lower, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], or rust-free steel. Nozzle plate 20
The one side entirely covers one surface of the flow path forming substrate 10 and also serves as a reinforcing plate that protects the silicon single crystal substrate from impact and external force. Further, the nozzle plate 20 may be formed of a material having a thermal expansion coefficient substantially the same as that of the flow path forming substrate 10. In this case, since the flow path forming substrate 10 and the nozzle plate 20 have substantially the same deformation due to heat, they can be easily joined using a thermosetting adhesive or the like.

Here, the size of the pressure generating chamber 12 that applies the ink droplet ejection pressure to the ink and the size of the nozzle opening 21 that ejects the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink drops per inch, it is necessary to accurately form the nozzle openings 21 with a diameter of several tens of μm.

On the other hand, on the elastic film 50 provided on the flow path forming substrate 10, the lower electrode film 60 having a thickness of, for example, about 0.2 μm and the piezoelectric film having a thickness of, for example, about 0.5 to 3 μm. Body layer 7
0 and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are laminated and formed by a process described later to form the piezoelectric element 30.
Configures 0. 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. Generally, 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 pressure generating chamber 12. Further, here, a portion which is composed of one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the lower electrode film 60 is the common electrode of the piezoelectric element 300, and the upper electrode film 80 is the individual electrode of the piezoelectric element 300.
There is no problem in reversing this due to the driving circuit and wiring.
In any case, the piezoelectric active portion is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by the driving of the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

Further, each upper electrode film 80, which is an individual electrode of the piezoelectric element 300, extends from the vicinity of the end opposite to the ink supply path 14 to the vicinity of the end of the flow path forming substrate 10.
For example, a lead electrode 90 made of gold (Au) or the like is connected, and the piezoelectric element 30 is provided near the end of the lead electrode 90.
An external wiring (not shown) connected to a drive circuit for driving 0 is connected.

Here, a method of manufacturing such an ink jet recording head, in particular, a method of forming a piezoelectric element and a pressure generating chamber will be described with reference to FIGS. 3 to 5 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction.

First, as shown in FIG. 3A, about 110 wafers of a silicon single crystal substrate to be the flow path forming substrate 10 are prepared.
An elastic film 50 made of silicon dioxide is formed by thermal oxidation in a 0 ° C. diffusion furnace.

Next, as shown in FIG. 3B, after the lower electrode film 60 is formed on the entire surface of the elastic film 50 by sputtering, the lower electrode film 60 is patterned to form an overall pattern. Platinum (Pt) or the like is suitable as a material for the lower electrode film 60. This is because the piezoelectric layer 70 described later, which is formed by the sputtering method or the sol-gel method, needs to be crystallized by baking at a temperature of about 600 to 1000 ° C. in the air atmosphere or the oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain the conductivity under such a high temperature and oxidizing atmosphere, and especially when lead zirconate titanate (PZT) is used as the piezoelectric layer 70. It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and platinum is preferable for these reasons.

Next, as shown in FIG. 3C, the piezoelectric layer 70 is formed. The piezoelectric layer 70 preferably has crystals oriented. For example, in the present embodiment, a so-called sol-gel method is used in which a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried, gelled, and fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. To form a piezoelectric layer 70 in which crystals are oriented. As a material for the piezoelectric layer 70, a lead zirconate titanate-based material is suitable for use in an inkjet recording head. The method for forming the piezoelectric layer 70 is not particularly limited, and may be formed by, for example, a sputtering method.

Further, after forming a lead zirconate titanate precursor film by a sol-gel method or a sputtering method,
A method of growing crystals at a low temperature by a high-pressure treatment method in an alkaline aqueous solution may be used.

In any case, in the piezoelectric body layer 70 thus formed, the crystals are preferentially oriented unlike the bulk piezoelectric body, and in the present embodiment, the piezoelectric body layer 70 has the crystals. It has a columnar shape. Note that the preferential orientation means that the crystal orientation direction is not disordered, and a specific crystal plane is oriented in a substantially constant direction. Further, a thin film having a columnar crystal means a state in which crystals having a substantially columnar body are aggregated in a plane direction with the central axes substantially aligned with the thickness direction to form a thin film. Of course, it may be a thin film formed of preferentially oriented granular crystals. The thickness of the piezoelectric layer manufactured in the thin film process is generally 0.2 to 5 μm.

Next, as shown in FIG. 3D, the upper electrode film 80 is formed. The upper electrode film 80 may be made of a material having high conductivity, and many metals such as aluminum, gold, nickel and platinum, and a conductive oxide can be used. In this embodiment, platinum is deposited by sputtering.

Next, as shown in FIG. 4A, only the piezoelectric layer 70 and the upper electrode film 80 are etched to etch the piezoelectric element 3.
00 patterning is performed. Further, a through hole 51 is formed so as to penetrate the lower electrode film 60 and the elastic film 50.

Next, as shown in FIG. 4B, the lead electrode 90 is formed. Specifically, for example, the lead electrode 90 made of gold (Au) or the like is formed over the entire surface of the flow path forming substrate 10, and is patterned for each piezoelectric element 300.

The above is the film forming process. After the film formation is performed in this manner, the flow path forming substrate 10 made of the silicon single crystal substrate is anisotropically etched by the above-described alkaline solution, and as shown in FIG. The communication section 13 and the ink supply path 14 are formed.

Next, as shown in FIG. 4 (d), the groove portion 15 is formed by anisotropically etching the flow path forming substrate 10 again in a step different from the pressure generating chamber 12 and the like.
By thus forming the groove 15 in a separate process from the pressure generating chamber 12, the groove 15 can be formed relatively easily and highly accurately by anisotropic etching.

Thereafter, as shown in FIG. 5A, the nozzle plate 20 having the nozzle openings 21 formed therein is bonded to the flow path forming substrate 10 with the adhesive 25. At this time, since the groove portion 15 communicating with the pressure generating chamber 12 is formed on the joint surface of the flow path forming substrate 10 with the nozzle plate 20,
The useless adhesive 25 flows into the groove 15 and the adhesive 2
5 excessively flows into the pressure generating chamber 12 and the nozzle opening 2
1 is not blocked by the adhesive 25. As a result, it is possible to prevent the occurrence of defective ink ejection, and to bond the flow path forming substrate 10 and the nozzle plate 20 well.

In particular, when a silicon single crystal substrate whose main surface is the (110) plane is used as the flow path forming substrate 10 as in this embodiment, defective ink ejection can be effectively prevented. That is, when the pressure generating chamber 12 is formed by anisotropically etching the flow path forming substrate 10 whose main surface is a (110) plane silicon single crystal substrate, the longitudinal end face of the pressure generating chamber 12 is the inner side thereof. 5B, the adhesive 25 that has flowed into the pressure generating chamber 12 becomes the inclined surface 12a that inclines toward the inclined surface 1a.
It collects between the nozzle 2a and the nozzle plate 20 and easily closes the nozzle opening 21. However, by providing the groove portion 15 that communicates with the longitudinal end portion of the pressure generating chamber 12, it is possible to suppress the wasteful adhesive 25 from flowing out to the pressure generating chamber 12, and thus it is possible to effectively prevent defective ink ejection. be able to.

Further, as in the present embodiment, the flow path forming substrate 1
When the pressure generating chambers 0 of 0 are arranged in a relatively high density,
Since the joining area with the nozzle plate 20 becomes smaller, the groove portion 15 can be provided to more effectively prevent the adhesive from flowing out.

The piezoelectric element 300, the pressure generating chamber 12 and the like described above are simultaneously formed as a large number of chips on one wafer by a series of film formation and anisotropic etching. After the process is completed, the channel forming substrate 10 of one chip size as shown in FIG. 1 is divided, and the divided channel forming substrate 10 is divided into the reservoir forming substrate 3 described later.
The ink jet recording head is obtained by sequentially bonding and integrating the 0 and the compliance substrate 40.

That is, as shown in FIGS. 1 and 2, a reservoir portion 31 forming at least a part of the reservoir 100 is provided on the piezoelectric element 300 side of the flow path forming substrate 10 in which the pressure generating chamber 12 and the like are formed. The reservoir forming substrate 30 that it has is joined. In this embodiment, the reservoir portion 31 penetrates the reservoir forming substrate 30 in the thickness direction and is formed across the width direction of the pressure generating chamber 12. Then, the reservoir portion 31 is provided with the passage forming substrate 10 through the through hole 51 that is provided to penetrate the elastic film 50 and the lower electrode film 60.
A reservoir 100 that communicates with the communication section 13 and serves as a common ink chamber for each pressure generating chamber 12 is configured.

On the other hand, the piezoelectric element 3 of the reservoir forming substrate 30.
In a region facing 00, a piezoelectric element holding portion 32 is provided that can seal the space while ensuring a space that does not hinder the movement of the piezoelectric element 300. The piezoelectric element 300 is sealed in the piezoelectric element holding portion 32,
Destruction due to the external environment such as atmospheric moisture is prevented.

As such a reservoir forming substrate 30, it is preferable to use a material having substantially the same coefficient of thermal expansion as that of the passage forming substrate 10 such as glass or a ceramic material. In this embodiment, the passage forming substrate 30 is used. It was formed using a silicon single crystal substrate of the same material as 10.

Further, the reservoir forming substrate 30 includes
A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is joined. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. Further, the fixing plate 42 is made of a hard material such as metal (for example, stainless steel having a thickness of 30 μm (SU
S) and the like). The reservoir 10 of this fixed plate 42
Since the region facing 0 is the opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only by the flexible sealing film 41, and the internal pressure changes. The flexible portion 33 is deformable by.

The ink jet recording head thus constructed takes in ink from an external ink supply means (not shown) and fills the interior from the reservoir 100 to the nozzle openings 21 with ink, and then an external drive circuit (not shown). A voltage is applied between the upper electrode film 80 and the lower electrode film 60 according to a recording signal from the elastic film 50, the lower electrode film 6
By flexurally deforming the piezoelectric layer 70 and the piezoelectric layer 70, the pressure inside the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 21.

(Embodiment 2) FIG. 6 is a plan view showing an essential part of an ink jet recording head according to Embodiment 2. As shown in FIG.

The present embodiment is an example in which a plurality of groove portions are provided so as to communicate with each other in the longitudinal direction of the pressure generating chamber 12, and FIG.
As shown in, the same as Embodiment 1 except that two groove portions 15A are provided so as to communicate with both widthwise end portions of each pressure generating chamber 12.

With this structure, as in the first embodiment, when the flow path forming substrate 10 and the nozzle plate 20 are bonded by the adhesive 25, useless adhesive flows into these groove portions 15A and pressure is applied. Since the outflow into the generation chamber 12 is prevented, the occurrence of defective ink ejection can be prevented.

The position at which the groove portion 15A is provided is not particularly limited. However, as in the present embodiment, by communicating with both ends of the pressure generating chamber 12 in the width direction, useless adhesive is provided in the groove portion 15A. It becomes easier to flow into the pressure generating chamber 12, and it is possible to more reliably prevent the pressure generating chamber 12 from flowing out.

(Other Embodiments) Although the respective embodiments of the present invention have been described above, the basic structure of the ink jet recording head is not limited to the above.

For example, as shown in FIG. 7, on the joint surface of the flow path forming substrate 10 with the nozzle plate 20, the recess 16 is formed together with the groove 15 communicating with the longitudinal end of the pressure generating chamber 12.
May be provided, and when the flow path forming substrate 10 and the nozzle plate 20 are bonded with the adhesive 25, useless adhesive may flow into the recess 16. Thereby, it is possible to more effectively prevent the waste adhesive from flowing out into the pressure generating chamber 12.

Further, for example, in the above-mentioned embodiment, the thin film type ink jet recording head manufactured by applying the film formation and the lithographic process is taken as an example, but the present invention is not limited to this and, for example, The present invention can also be applied to a thick film type ink jet recording head formed by a method such as attaching a green sheet.

Further, in the above-mentioned embodiment, the ink jet recording head having the flexural displacement type piezoelectric element has been described. For example, a vertical structure having a structure in which a piezoelectric material and an electrode forming material are alternately sandwiched and laminated. It can be applied to an ink jet recording head having a vibration mode piezoelectric element.

As described above, the present invention can be applied to ink jet recording heads having various structures as long as it does not violate the gist thereof.

Further, the ink jet recording head of the above-described embodiment constitutes a part of the recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on the ink jet recording apparatus. Figure 8
It is a schematic diagram showing an example of the ink jet type recording device.

As shown in FIG. 8, in the recording head units 1A and 1B having an ink jet recording head, the cartridges 2A and 2B constituting the ink supply means are detachably provided, and the recording head units 1A and 1B are provided.
The carriage 3 on which B is mounted is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B are, for example,
The black ink composition and the color ink composition are respectively discharged.

Then, the driving force of the drive motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, so that the carriage 3 having the recording head units 1A and 1B mounted thereon follows the carriage shaft 5. Be moved. On the other hand, a platen 8 is provided on the apparatus body 4 along the carriage 3. The platen 8 can be rotated by the driving force of a paper feed motor (not shown) so that the recording sheet S, which is a recording medium such as paper fed by a paper feed roller or the like, is conveyed on the platen 8. Has become.

[0077]

As described above, according to the present invention, a groove portion communicating with the longitudinal end of each pressure generating chamber on the side of communication with the nozzle opening is provided on the surface of the flow path forming substrate that is joined to the nozzle plate. Therefore, it is possible to prevent wasteful adhesive from flowing out into the pressure generating chamber, and prevent defective ink ejection due to clogging of the nozzle openings.

[Brief description of drawings]

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

2A and 2B are a plan view and a sectional view of the ink jet recording head according to the first embodiment of the invention.

FIG. 3 is a cross-sectional view showing the manufacturing process of the ink jet recording head according to the first embodiment of the invention.

FIG. 4 is a cross-sectional view showing the manufacturing process of the inkjet recording head according to the first embodiment of the invention.

FIG. 5 is a cross-sectional view showing the manufacturing process of the ink jet recording head according to the first embodiment of the invention.

FIG. 6 is a plan view showing a main part of an ink jet recording head according to a second embodiment of the invention.

FIG. 7 is a plan view showing a main part of an ink jet recording head according to another embodiment of the present invention.

FIG. 8 is a schematic diagram of an inkjet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

10 Flow path forming substrate 11 partitions 12 Pressure generation chamber 13 Communication 14 Ink supply path 15,15A groove 16 recess 20 nozzle plate 21 nozzle opening 50 elastic membrane 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 300 Piezoelectric element

Claims (10)

[Claims] 1. A nozzle plate having a nozzle opening,
A flow path forming substrate that defines a pressure generating chamber that communicates with the nozzle opening, and a region of the flow path forming substrate that corresponds to the pressure generating chamber is provided via a vibration plate to discharge ink into the pressure generating chamber. In the ink jet recording head including a piezoelectric element that applies a pressure for, the flow path forming substrate and the nozzle plate are bonded via an adhesive, and the bonding surface of the flow path forming substrate with the nozzle plate is bonded. An ink jet recording head, characterized in that at least one groove portion, which is in communication with the longitudinal end portion of each pressure generating chamber on the communication side with the nozzle opening, and in which the adhesive has entered, is provided. 2. The width of the groove portion according to claim 1,
An inkjet recording head having a size smaller than μm and a depth smaller than 5 μm. 3. The groove portion according to claim 1 or 2,
An ink jet recording head, which is provided so as to communicate with a substantially central portion in the width direction of the pressure generating chamber. 4. The groove according to claim 1 or 2,
An ink jet recording head, wherein the pressure generating chamber is provided so as to communicate with at least both ends in the width direction of the pressure generating chamber. 5. The ink jet recording head according to claim 1, wherein an adhesive that bonds the flow path forming substrate and the nozzle plate is filled in the groove. . 6. The ink jet recording head according to claim 1, wherein the pressure generating chambers have an arrangement density of 200 dpi or more. 7. The flow path forming substrate according to claim 1, wherein the flow path forming substrate is made of a silicon single crystal substrate, and the pressure generating chamber and the groove are formed by anisotropic etching. Inkjet recording head. 8. The ink jet recording head according to claim 7, wherein the flow path forming substrate is made of a silicon single crystal substrate whose main surface is a (110) plane. 9. The ink jet recording head according to claim 7, wherein the pressure generating chamber and the groove are formed in separate steps. 10. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.