JP2002187271A - Ink jet recording head and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head and an ink jet recording device, which prevent a diaphragm from being destroyed by the drive of a piezoelectric element. SOLUTION: The ink jet recording head is provided with a pressure generating chamber 12 communicating with a nozzle opening, a lower electrode 60 provided via the diaphragm in a region corresponding to the chamber 12, and the piezoelectric element 300 composed of a piezoelectric body layer 70 and an upper electrode 80. A lead electrode 90, which is extended from the upper electrode 80 to a section on a peripheral wall, is provided on the side of one longitudinal end of the chamber 12. In a region facing the chamber 12, there are provided a piezoelectric body active part 320, wherein the piezoelectric element 300 serves as a substantial drive part, and a piezoelectric body inactive part 330 which is installed at least on the side of the other longitudinal end of the chamber 12 and not driven substantially in spite of the possession of the layer 70 continuing from the active part 320. In addition, the inactive part 330 is extended outside the region facing the chamber 12. Consequently, stiffness is enhanced in the diaphragm near the longitudinal end of the chamber 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets, which is constituted by a vibrating plate. TECHNICAL FIELD The present invention relates to an ink jet recording head and an ink jet recording apparatus for ejecting ink droplets by using an ink jet recording head.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber to pass through the nozzle opening. Two types of ink jet recording heads that eject ink droplets have been commercialized, one using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and the other using a flexural vibration mode piezoelectric actuator. ing.

In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric element into contact with the diaphragm, so that a head suitable for high-density printing can be manufactured. There is a problem in that a difficult process of cutting into a comb shape in accordance with the arrangement pitch of the openings and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required, and the manufacturing process is complicated.

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

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

[0006]

However, the above-described ink jet recording head has a problem that cracks or the like are generated on the diaphragm due to repeated deformation by driving of the piezoelectric element. In particular, in the region near the longitudinal end of the pressure generating chamber, the amount of deformation due to the driving of the piezoelectric element is large, so that cracks and the like are likely to be broken.

[0007] In view of such circumstances, an object of the present invention is to provide an ink jet type recording head and an ink jet type recording apparatus which prevent breakage of a diaphragm due to driving of a piezoelectric element.

[0008]

According to a first aspect of the present invention for solving the above-mentioned problems, a pressure generating chamber communicating with a nozzle opening and a region corresponding to the pressure generating chamber are provided via a diaphragm. In an ink jet recording head including a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode, a lead electrode extending on the peripheral wall from the upper electrode on one end side in the longitudinal direction of the pressure generating chamber, The piezoelectric element has a piezoelectric active portion serving as a substantial driving portion and a piezoelectric layer provided at least on the other end side in the longitudinal direction of the pressure generating chamber and continuous from the piezoelectric active portion, but is not substantially driven. An ink jet recording method comprising: a piezoelectric non-active portion in a region facing the pressure generating chamber; and the piezoelectric non-active portion extending to an area outside the pressure generating chamber. H Located in.

In the first aspect, since the piezoelectric non-active portion which is not driven is formed on the diaphragm near the longitudinal end of the pressure generating chamber, the rigidity of the diaphragm is improved. Thus, the destruction of the diaphragm is prevented.

According to a second aspect of the present invention, in the first aspect, a piezoelectric non-active member extending from a region facing the pressure generating chamber to an outside of the region at both longitudinal ends of the piezoelectric member. And an ink jet recording head comprising:

In the second aspect, the diaphragm is prevented from being broken at both ends in the longitudinal direction of the pressure generating chamber.

According to a third aspect of the present invention, there is provided an ink jet recording head according to the first or second aspect, wherein the piezoelectric layer has crystals preferentially oriented.

In the third aspect, as a result of the piezoelectric layer being formed in the thin film process, the crystals are preferentially oriented.

According to a fourth aspect of the present invention, there is provided an ink jet recording head according to the third aspect, wherein the piezoelectric layer has a columnar crystal.

In the fourth aspect, as a result of the piezoelectric layer being formed in the thin film process, the crystals are columnar.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the piezoelectric layer has a thickness of 0.5 to 3 μm.
m, and m is m.

According to the fifth aspect, the head can be downsized by making the thickness of the piezoelectric layer relatively thin.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the piezoelectric inactive portion on the other end side in the longitudinal direction of the piezoelectric active portion removes the lower electrode. An ink jet recording head is characterized by being formed by:

In the sixth aspect, by removing the lower electrode, the inactive portion of the piezoelectric body can be easily formed.

According to a seventh aspect of the present invention, in any one of the first to fifth aspects, the piezoelectric inactive portion on the other end side in the longitudinal direction of the piezoelectric active portion removes the upper electrode. An ink jet recording head is characterized by being formed by:

In the seventh aspect, the piezoelectric inactive portion can be easily formed by removing the upper electrode.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, a boundary between at least an end of the pressure generating chamber and a peripheral wall of the piezoelectric layer constituting the piezoelectric inactive portion. The width in the vicinity of a portion crossing the pressure generating chamber is wider than the width of the pressure generating chamber.

In the eighth aspect, the diaphragm at the boundary between the longitudinal end of the pressure generating chamber and the peripheral wall is completely covered by the piezoelectric inactive portion, so that the rigidity of the diaphragm is more reliably improved. I do.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the piezoelectric inactive portion on one end side in the longitudinal direction of the piezoelectric active portion removes the lower electrode. An ink jet recording head is characterized by being formed by:

In the ninth aspect, by removing the lower electrode, the non-active portion of the piezoelectric body can be easily formed, and the lead electrode can be easily extended.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each of the layers constituting the piezoelectric element is formed by film formation. An ink jet recording head is formed by a lithography method.

In the tenth aspect, the pressure generating chamber can be formed relatively easily with high precision and high density.

According to an eleventh aspect of the present invention, there is provided an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to tenth aspects.

According to the eleventh aspect, it is possible to realize an ink jet recording head having improved durability and reliability of the head.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail 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 single crystal silicon substrate having a plane orientation of (110) in this embodiment. 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 formed in advance by thermal oxidation.

In the flow path forming substrate 10, pressure generating chambers 12 divided by a plurality of partition walls 11 are provided in parallel in the width direction by anisotropically etching a silicon single crystal substrate, and the pressure generating chambers 12 are provided on the outside in the longitudinal direction. Is a communication part 13 which constitutes a part of a reservoir 100 which communicates with a reservoir part of a reservoir forming substrate which will be described later and serves as a common ink chamber of each pressure generating chamber 12.
Are formed, and are communicated with one end in the longitudinal direction of each pressure generating chamber 12 via the ink supply path 14.

Here, in the anisotropic etching, when the 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 depth processing of a parallelogram formed by the 1) plane and two oblique second (111) planes, and the pressure generating chambers 12 can be arranged at high density. it can.

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 on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic film 50 almost through 0. Here, the elastic film 50 is
The amount attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small. Each of the ink supply passages 14 communicating with one end of each of the pressure generating chambers 12 is formed shallower than the pressure generating chambers 12 and maintains a constant flow resistance of the ink flowing into the pressure generating chambers 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.

The thickness of the flow path forming substrate 10 is selected to be optimal according to the density of the pressure generating chambers 12. For example, when the pressure generating chambers 12 are arranged so as to obtain a resolution of 180 dpi, the thickness of the flow path forming substrate 10 is preferably about 180 to 280 μm, and more preferably about 220 μm. Further, for example, when the pressure generating chambers 12 are arranged so as to obtain a resolution of 360 dpi, the thickness of the flow path forming substrate 10 is
The thickness is preferably 100 μm or less. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

On the other side of the flow path forming substrate 10,
A nozzle plate 20 provided with a nozzle opening 21 communicating with the pressure supply chamber 12 on the side opposite to the ink supply path 14 is fixed via an adhesive or a heat welding film. The thickness of the nozzle plate 20 is, for example, 0.1 to 1
mm, the coefficient of linear expansion is 300 ° C. or less, for example, 2.5 to
It is made of 4.5 [× 10 ⁻⁶ / ° C.] glass-ceramic or non-rusting steel. The nozzle plate 20 entirely 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. Further, the nozzle plate 20 is connected to the flow path forming substrate 10.
May be formed of a material having substantially the same thermal expansion coefficient as that of the material. In this case, since the deformation of the flow path forming substrate 10 and the nozzle plate 20 due to heat become substantially the same, it is possible to easily join them using a thermosetting adhesive or the like.

Here, the size of the pressure generating chamber 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 21 for ejecting 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 droplets per inch, the nozzle openings 21 need to be formed with a diameter of several tens of μm with high accuracy.

On the other hand, on the elastic film 50 provided on the flow path forming substrate 10, a lower electrode film 60 having a thickness of, for example, about 0.2 μm and a lower electrode film 60 having a thickness of, for example, about 0.5 to 3 μm. A piezoelectric layer 70 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, and the piezoelectric element 30 is formed.
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. 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 of the pressure generating chambers 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric layer 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present 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 an individual electrode of the piezoelectric element 300. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Also, here
The combination of the piezoelectric element 300 and the diaphragm whose displacement is generated by driving the piezoelectric element 300 is referred to as a piezoelectric actuator.

Here, the structure of such a piezoelectric element 300 will be described in detail.

As shown in FIGS. 3A and 3B, the lower electrode film 60 constituting a part of the piezoelectric element 300 is continuously formed in a region facing a plurality of pressure generating chambers 12 arranged in parallel. It is provided and is patterned in the vicinity of both ends in the longitudinal direction in a region facing the pressure generating chamber 12. That is, the piezoelectric element 3
00 is a piezoelectric active part 320 which is a substantial driving part;
The piezoelectric inactive portion 330, which is provided at each longitudinal end of the piezoelectric active portion 320 and has the piezoelectric layer 70 continuous with the piezoelectric active portion 320 but is not substantially driven, faces the pressure generating chamber 12. In the area you want. Further, in the present embodiment, each of the piezoelectric inactive portions 330 extends from a region facing the pressure generating chamber 12 to a peripheral wall outside both ends in the longitudinal direction of the pressure generating chamber 12.

It should be noted that the upper electrode film 80 is
0, the piezoelectric layer 70 and the elastic film 5
It is connected to an external wiring (not shown) via a lead electrode 90 extending on the reference numeral 0.

As described above, in the present embodiment, the piezoelectric non-active portions 330 are provided on both sides in the longitudinal direction of the piezoelectric active portion 320, and the piezoelectric non-active portions 330 extend to the outside of the pressure generating chamber 12. Therefore, the vibrating plate near the longitudinal end of the pressure generating chamber 12 is covered by the non-driven piezoelectric inactive portion 330. Therefore, the rigidity of the diaphragm is improved, and cracks and the like are not generated in the diaphragm even by repeated displacement due to driving of the piezoelectric element 300, and durability is improved.

Since the rigidity of the diaphragm is improved, the diaphragm is not broken even when the piezoelectric element 300 is driven at a relatively high voltage. Therefore, the amount of ink ejected by driving the piezoelectric element 300 at a relatively high voltage is increased,
Printing speed can be improved.

In the present embodiment, the piezoelectric inactive portions 330 are provided at both ends in the longitudinal direction of the pressure generating chamber 12, respectively. However, the present invention is not limited to this. As shown in FIG. Alternatively, the piezoelectric non-active portion 330 may be provided only on the end of the piezoelectric active portion 320 opposite to the side from which the lead electrode 90 is pulled out, that is, only on the tip end of the piezoelectric element 300. In such a configuration, the rigidity of the diaphragm on the tip end side of the piezoelectric element 300 is improved by the piezoelectric inactive portion 330, and the lead electrode 90 extends on the diaphragm on the lead-out side of the lead electrode 90. Therefore, the rigidity of the diaphragm is improved by the lead electrodes 90.

The method of manufacturing such an ink jet recording head is not particularly limited, but one example thereof will be described below with reference to FIGS. 4 and 5
Is a longitudinal sectional view of the pressure generating chamber 12. FIG.

First, as shown in FIG. 4A, a wafer of a silicon single crystal substrate serving as a flow path forming
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG. 4B, after forming the lower electrode film 60 on the entire surface of the elastic film 50 by sputtering, the lower electrode film 60 is patterned to form an entire pattern. Preferable material for the lower electrode film 60 is platinum (Pt) or the like. This is because it is necessary to crystallize a piezoelectric layer 70 described later formed by a sputtering method or a sol-gel method by firing at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. In particular, when the piezoelectric layer 70 is made of lead zirconate titanate (PZT), It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and for these reasons, platinum is preferred.

Next, as shown in FIG. 4C, a piezoelectric layer 70 is formed. In the piezoelectric layer 70, it is preferable that crystals are oriented. For example, in the present embodiment, a so-called sol-gel method in which a so-called sol in which a metal organic substance is dissolved and dispersed in a catalyst is applied and dried to form a gel, and then 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 when used in an ink jet recording head. The method for forming the piezoelectric layer 70 is not particularly limited, and may be, for example, a sputtering method.

Further, after forming a precursor film of lead zirconate titanate 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, unlike the bulk piezoelectric material, the crystal is preferentially oriented in the piezoelectric layer 70 formed in this way, and in the present embodiment, the piezoelectric layer 70 is It is formed in a column shape. Note that the preferential orientation refers to a state in which a crystal orientation direction is not disordered and a specific crystal plane is oriented in a substantially constant direction. In addition, a crystal having a columnar thin film refers to a state in which substantially columnar crystals are gathered in a plane direction with their central axes substantially aligned in 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. 4D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as aluminum, gold, nickel, and platinum, and a conductive oxide. In the present embodiment, platinum is formed by sputtering.

Next, as shown in FIG. 5A, only the piezoelectric layer 70 and the upper electrode film 80 are etched to form a piezoelectric element 3 comprising a piezoelectric active portion 320 and a piezoelectric non-active portion 330.
00 patterning is performed. That is, by patterning the piezoelectric layer 70 and the upper electrode film 80 for each pressure generating chamber 12, the region where the lower electrode film 60 of the piezoelectric element 300 is formed becomes the piezoelectric active portion 320, and the lower electrode film 6
The region where 0 is removed becomes the piezoelectric inactive portion 330.

In this embodiment, the elastic film 50 is etched simultaneously with the piezoelectric layer 70 and the upper electrode film 80,
A communication hole 51 that connects the communication portion 13 and a reservoir portion 31 described later is formed.

Next, as shown in FIG. 5B, a lead electrode 90 is formed. Specifically, for example, a lead electrode 90 made of, for example, gold (Au) 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 forming the film in this manner, anisotropic etching of the silicon single crystal substrate was performed using the above-described alkali solution, and FIG.
As shown in (c), the pressure generating chamber 12, the communication section 13, the ink supply path 14, and the like are formed.

In practice, a large number of chips are simultaneously formed on a single wafer by such a series of film formation and anisotropic etching. After the process, one chip as shown in FIG. It is divided for each flow path forming substrate 10 having a size. Then, a reservoir forming substrate 30 and a compliance substrate 40, which will be described later, are sequentially bonded and integrated with the divided flow path forming substrate 10 to form an ink jet recording head.

That is, as shown in FIGS. 1 and 2, a reservoir section 31 constituting 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 chambers 12 and the like are formed. The reservoir forming substrate 30 is joined. In the present embodiment, the reservoir portion 31 is formed so as to penetrate the reservoir forming substrate 30 in the thickness direction and to extend in the width direction of the pressure generating chamber 12. Then, the reservoir portion 31 is formed through the elastic film 50 and the lower electrode film 60 through a through hole 51 provided through the flow path forming substrate 10.
The reservoir 100 is configured to communicate with the communication portion 13 of the pressure generating chamber 12 and serve as a common ink chamber for each pressure generating chamber 12.

As the reservoir forming substrate 30, for example, it is preferable to use a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10, such as glass or a ceramic material. It was formed using a silicon single crystal substrate of the same material. As a result, as in the case of the nozzle plate 20 described above, both can be securely bonded to each other even at a high temperature using a thermosetting adhesive. Therefore, the manufacturing process can be simplified.

Further, the reservoir forming substrate 30 includes:
The compliance substrate 40 including the sealing film 41 and the 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 31. Has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SU) having a thickness of 30 μm.
S) etc.). The reservoir 10 of the fixing plate 42
Since the region opposing to 0 is an opening 43 completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with the sealing film 41 having flexibility, and the internal pressure changes. Thus, the flexible portion 32 is deformable.

Further, an ink inlet 35 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 substantially outside the central portion in the longitudinal direction of the reservoir 100. Further, the reservoir forming substrate 30 is provided with an ink introduction path 36 that communicates the ink introduction port 35 with the side wall of the reservoir 110.

On the other hand, the piezoelectric element 3 of the reservoir forming substrate 30
A piezoelectric element holding portion 33 capable of sealing the space is provided in a region opposed to 00 while securing a space that does not hinder the movement of the piezoelectric element 300. At least the piezoelectric active portion 320 of the piezoelectric element 300 is sealed in the piezoelectric element holding portion 33 to prevent the piezoelectric element 300 from being destroyed due to an external environment such as moisture in the atmosphere.

The ink jet recording head thus constructed takes in ink from an ink inlet 35 connected to an external ink supply means (not shown) and fills the interior from the reservoir 110 to the nozzle opening 21 with ink. By applying a voltage between the upper electrode film 80 and the lower electrode film 60 in accordance with a recording signal from an external drive circuit (not shown), the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are flexibly deformed. Then, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle opening 21.

(Embodiment 2) FIGS. 6A and 6B are a plan view and a sectional view showing a main part of an ink jet recording head according to Embodiment 2. FIG.

As shown in FIG. 6, in the present embodiment, the piezoelectric body non-active portion 330A provided at the end of the pressure generating chamber 12 opposite to the lead electrode 90, that is, at the tip of the piezoelectric element 300 is provided. This is an example formed by removing the upper electrode film 80.

That is, in the present embodiment, the lower electrode film 60
Are formed continuously on the outer peripheral wall of the pressure generating chamber 12 without being patterned in the pressure generating chamber 12 on the tip end side of the piezoelectric element 300. On the tip end side of the piezoelectric element 300, the upper electrode film 80 is patterned in a region facing the pressure generating chamber 12, and the ends of the upper electrode film 80 are divided into the piezoelectric active portion 320 and the piezoelectric non-active portion. 3
It is the boundary with 30.

As described above, even when the piezoelectric inactive portion 330A is formed by removing the upper electrode film 80, the diaphragm near the longitudinal end of the pressure generating chamber 12 can be formed similarly to the first embodiment. Of the diaphragm can be prevented, and the occurrence of cracks or the like in the diaphragm can be prevented.

(Embodiment 3) FIG. 7 is a plan view showing a main part of an ink jet recording head according to Embodiment 3. FIG.

In this embodiment, as shown in FIG. 7, a portion of the piezoelectric inactive portion 330 that crosses the boundary between the pressure generating chamber 12 and the peripheral wall has a wide portion 330 wider than the width of the pressure generating chamber 12.
It is the same as the first embodiment except that a is provided.

In the structure of this embodiment, the vibrating plate near the longitudinal end of the pressure generating chamber 12 is completely covered by the non-piezoelectric member 330, so that the rigidity of the vibrating plate is more reliably improved. In addition, the occurrence of cracks and the like due to the driving of the piezoelectric element 300 can be reliably prevented.

In this embodiment, the piezoelectric non-active portion 330 is formed by removing the lower electrode film 60. However, the piezoelectric non-active portion 330 is formed by removing the upper electrode film 80. May be formed.

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

For example, in the above embodiment, the lower electrode film 6
The piezoelectric non-active portion 330 is formed by removing the zero or upper electrode film 80, but the present invention is not limited to this. For example, a low dielectric insulating material is provided between the piezoelectric layer 70 and the upper electrode film 80. It may be formed by providing a layer, or may be formed by partially doping the piezoelectric layer 70 to make it inactive.

In each of the embodiments described above, a thin film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example.
Of course, the present invention is not limited to this. For example, a structure in which substrates are stacked to form a pressure generating chamber, a structure in which a green sheet is attached or a piezoelectric layer is formed by screen printing, or a crystal formed by a hydrothermal method or the like The present invention can be applied to ink jet recording heads having various structures, such as one that forms a piezoelectric layer by growth.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the spirit of the present invention is not contradicted.

The ink jet recording head of each of these embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. FIG. 8 is a schematic view showing an example of the ink jet recording apparatus.

As shown in FIG. 8, the recording head units 1A and 1B having ink jet recording heads are provided with detachable cartridges 2A and 2B constituting ink supply means.
The carriage 3 on which B is mounted is provided movably in the axial direction on a carriage shaft 5 attached to the apparatus main body 4. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. Moved. On the other hand, the apparatus main body 4 is provided with a platen 8 along the carriage 3. The platen 8 can be rotated by a driving force of a paper feed motor (not shown), and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller, is wound around the platen 8 and conveyed. It has become so.

[0079]

As described above, according to the present invention,
By providing a piezoelectric inactive portion continuous from the piezoelectric active portion at least on the end side of the pressure generating chamber opposite to the lead electrode extraction side, the rigidity of the diaphragm near the longitudinal end of the pressure generating chamber is increased. Thus, cracks and the like can be prevented from being generated in the diaphragm even by repeated deformation due to driving of the piezoelectric element.

[Brief description of the drawings]

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

FIG. 2 is a plan view and a cross-sectional view of the inkjet recording head according to the first embodiment of the present invention, showing the same.

FIGS. 3A and 3B are a plan view and a cross-sectional view illustrating a main part of the inkjet recording head according to the first embodiment of the invention.

FIG. 4 is a cross-sectional view illustrating a thin-film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a thin-film manufacturing process according to the first embodiment of the present invention.

FIG. 6 is a plan view and a cross-sectional view illustrating a main part of an ink jet recording head according to a second embodiment of the present invention.

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flow path forming substrate 11 Partition wall 12 Pressure generating chamber 20 Nozzle plate 21 Nozzle opening 50 Elastic film 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 300 Piezoelectric element 320 Piezoelectric active part 330, 330A Piezoelectric non-active Part 330a wide part

Claims (11)

[Claims] 1. An ink jet type comprising: a pressure generating chamber communicating with a nozzle opening; and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode provided in a region corresponding to the pressure generating chamber via a vibration plate. In the recording head, a lead electrode extending from the upper electrode to the peripheral wall is provided on one end side of the pressure generating chamber in the longitudinal direction, and the piezoelectric element is a piezoelectric active part that is substantially a driving part, and at least the piezoelectric active part. A piezoelectric non-active portion which is provided on the other longitudinal end side of the pressure generating chamber and has a piezoelectric layer continuous from the piezoelectric active portion, but is not substantially driven, in a region opposed to the pressure generating chamber; An ink jet recording head, wherein the non-active portion of the piezoelectric body extends to an outside of a region facing the pressure generating chamber. 2. The piezoelectric element according to claim 1, further comprising: a piezoelectric non-active portion extending from a region facing the pressure generating chamber to an outside of the region at both longitudinal ends of the piezoelectric active portion. Ink jet recording head. 3. The ink jet recording head according to claim 1, wherein crystals of the piezoelectric layer are preferentially oriented. 4. The ink jet recording head according to claim 3, wherein the piezoelectric layer has a columnar crystal. 5. The ink jet recording head according to claim 1, wherein the thickness of the piezoelectric layer is 0.5 to 3 μm. 6. The piezoelectric active portion according to claim 1, wherein the piezoelectric non-active portion on the other end in the longitudinal direction of the piezoelectric active portion is formed by removing the lower electrode. Inkjet recording head. 7. The piezoelectric active part according to claim 1, wherein the piezoelectric non-active part on the other end side in the longitudinal direction of the piezoelectric active part is formed by removing the upper electrode. Inkjet recording head. 8. The piezoelectric device according to claim 1, wherein a width of at least a portion of the piezoelectric layer constituting the non-piezoelectric active portion in the vicinity of a portion crossing a boundary between an end of the pressure generating chamber and a peripheral wall is: An ink jet recording head, which is wider than the pressure generating chamber. 9. The piezoelectric non-active portion at one end in the longitudinal direction of the piezoelectric active portion according to any one of claims 1 to 8, wherein the piezoelectric non-active portion is formed by removing the lower electrode. Inkjet recording head. 10. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed by anisotropic etching on a silicon single crystal substrate, and each layer constituting the piezoelectric element is formed by film formation and lithography. An ink jet recording head, characterized in that: 11. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.