JP2003326723A - Method of inspecting actuator device and method of inspecting inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of inspecting an actuator device and a method of inspecting an inkjet recording head capable of discriminating comparatively accurately a displacement characteristic of a diaphragm driven by a piezoelectric element. <P>SOLUTION: The displacement characteristic is discriminated by performing at least a driving/measuring process for measuring an electrostatic capacitance of a piezoelectric material layer by applying a predetermined voltage to the piezoelectric element under condition that the piezoelectric element can be driven. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting an actuator device having a piezoelectric element that is displaced by applying a voltage to a piezoelectric material layer, and more particularly to a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets. The present invention relates to a method for inspecting an ink jet recording head in which a part of a diaphragm is formed, a piezoelectric element is formed on the surface of the diaphragm, and ink droplets are ejected by displacement of the piezoelectric element.

[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. As an ink jet recording head for ejecting ink droplets, for example, one using a flexural vibration mode actuator device is known.

In such an ink jet recording head, for example, a green sheet of a piezoelectric material is attached according to the shape of the pressure generating chamber, or the piezoelectric material is applied by printing and then baked. Although the piezoelectric element can be built in the diaphragm by a simple process, there is a problem that high frequency ejection is difficult. And
In order to solve such a problem, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent No. 289352, a piezoelectric layer having a two-layer structure in which the amount of deformation of the piezoelectric element is increased is disclosed.

The ink jet type recording head provided with this multilayer laminated piezoelectric element is capable of relatively high frequency ejection. However, since the thickness of the piezoelectric layer causes an error when the piezoelectric element is formed, its characteristics. There is a problem that is not uniform. In particular, when the piezoelectric layer is applied by printing or the like, the error in the thickness tends to be particularly large. For this reason,
When forming a piezoelectric element, the capacitance of the piezoelectric layer and the resonance frequency of the piezoelectric element are measured to identify the characteristics of the piezoelectric element, and the piezoelectric element is driven with a drive waveform suitable for the characteristics.

[0005]

However, in the ink jet recording head including the piezoelectric element having such a multilayer structure, for example, the positional relationship between the pressure generating chamber and the piezoelectric element is caused by a dimensional error when the piezoelectric element is formed. When the optimum drive waveform is selected by identifying the characteristics of the piezoelectric element based on the measurement results of the resonance frequency of the piezoelectric element, etc. However, there is a problem in that the displacement characteristic due to the driving of is not obtained.

Further, such a problem also exists in an actuator device mounted on a liquid ejecting head such as a liquid crystal ejecting head or a color material ejecting head.

In view of such circumstances, the present invention provides an inspection method for an actuator device and an inspection method for an ink jet recording head, which are capable of identifying displacement characteristics of a diaphragm caused by driving a piezoelectric element relatively accurately. Is an issue.

[0008]

A first aspect of the present invention for solving the above problems is to provide a flow path forming substrate in which a pressure generating chamber is formed, and the pressure generating chamber on one side of the flow path forming substrate. A piezoelectric element provided in a region opposite to the piezoelectric element via a vibration plate, and causing a pressure change in the pressure generating chamber by flexibly displacing the piezoelectric element. An actuator device characterized in that a characteristic is identified by performing at least a drive measurement step of applying a predetermined voltage to the piezoelectric element under a condition in which the element can be driven to measure the capacitance of the piezoelectric layer. The inspection method is.

In the first aspect, the characteristics of the actuator device, that is, the displacement characteristics of the piezoelectric element and the diaphragm can be accurately identified.

A second aspect of the present invention is the actuator according to the first aspect, wherein in the drive measuring step, a predetermined voltage having a frequency lower than the resonance frequency of the piezoelectric element is applied to the piezoelectric element. It is in the inspection method of the device.

In the second aspect, the characteristics of the actuator device can be identified while reliably driving the piezoelectric element.

A third aspect of the present invention is the static measurement step according to the first or second aspect, in which a predetermined voltage is applied at a frequency at which the piezoelectric element is not driven to measure the capacitance of the piezoelectric layer. Is further performed, and the characteristics thereof are identified based on the measurement results of the drive measurement step and the static measurement step.

In the third aspect, the characteristic of the actuator device caused by the capacitance of the piezoelectric layer, that is, the characteristic of each piezoelectric element can be accurately identified by the static measurement step.

According to a fourth aspect of the present invention, in the third aspect, in the static measurement step, a predetermined voltage having a frequency higher than a resonance frequency of the piezoelectric layer is applied to the piezoelectric element. It is in the inspection method of the actuator device.

According to the fourth aspect, the piezoelectric element can be surely kept in a stationary state, and the characteristics of the piezoelectric element can be identified more accurately.

According to a fifth aspect of the present invention, in the third aspect, a voltage lower than the resonance frequency of the piezoelectric element and not driving the piezoelectric element is applied in the static measurement step. It is a method of inspecting a characteristic actuator device.

In the fifth aspect, the static measurement step can be executed also by changing the voltage applied to the piezoelectric element.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the voltage applied to the piezoelectric element is 1/10 or more of the drivable voltage of the piezoelectric element. There is a method of inspecting an actuator device for the same.

In the sixth aspect, the characteristics of the actuator device can be identified relatively easily and accurately by applying a predetermined voltage to the piezoelectric element.

A seventh aspect of the present invention is the piezoelectric element according to any one of the first to sixth aspects, wherein the piezoelectric element is composed of a lower piezoelectric layer and an upper piezoelectric layer laminated on each other. , An individual electrode provided between the lower piezoelectric layer and the upper piezoelectric layer and independent for each piezoelectric element, and a plurality of piezoelectric elements provided between the vibrating plate and the lower piezoelectric layer. A method of inspecting an actuator device, comprising: a common lower common electrode and a common upper electrode provided on the upper piezoelectric layer and electrically connected to the common lower electrode.

In the seventh aspect, the displacement characteristics of the piezoelectric element and the diaphragm can be accurately identified even when the piezoelectric element has a piezoelectric layer composed of a plurality of layers.

An eighth aspect of the present invention oscillates in a flow passage forming substrate in which a pressure generating chamber communicating with the nozzle opening is formed, and in a region facing the pressure generating chamber on one side of the flow passage forming substrate. An ink jet recording apparatus comprising: an actuator device having a piezoelectric element provided via a plate, wherein the piezoelectric element is flexibly displaced to generate a pressure change in the pressure generating chamber, thereby ejecting an ink droplet from the nozzle opening. A method for inspecting a head, the characteristic of which is obtained by at least performing a drive measurement step of applying a predetermined voltage to the piezoelectric element under a condition in which the piezoelectric element can be driven to measure the capacitance of the piezoelectric layer. Is a method for inspecting an inkjet recording head.

In the eighth aspect, the characteristic of the actuator device, that is, the displacement characteristic of the piezoelectric element and the diaphragm can be accurately identified.

A ninth aspect of the present invention is characterized in that, in the eighth aspect, a predetermined voltage having a frequency lower than a resonance frequency of the piezoelectric layer is applied to the piezoelectric element in the drive measuring step. It is in the method of inspecting an inkjet recording head.

In the ninth aspect, the characteristics of the actuator device can be identified while reliably driving the piezoelectric element.

In a tenth aspect of the present invention, in the eighth or ninth aspect, the capacitance of the piezoelectric layer is measured by applying a predetermined voltage to the piezoelectric element at a frequency that does not drive the piezoelectric element. The method for inspecting an ink jet recording head is characterized in that the static measurement step is further executed, and the characteristics thereof are identified based on the measurement results of the drive measurement step and the static measurement step.

In the tenth aspect, the characteristic of the actuator device caused by the capacitance of the piezoelectric layer, that is, the characteristic of each piezoelectric element can be accurately identified by the static measurement step.

An eleventh aspect of the present invention is characterized in that, in the tenth aspect, in the static measuring step, a predetermined voltage having a frequency higher than a resonance frequency of the piezoelectric layer is applied to the piezoelectric element. It is in the method of inspecting an inkjet recording head.

In the eleventh aspect, the static measurement step can be executed also by changing the voltage applied to the piezoelectric element.

According to a twelfth aspect of the present invention, in the tenth aspect, a voltage lower than a resonance frequency of the piezoelectric element and not driving the piezoelectric element is applied in the static measurement step. It is a characteristic method for inspecting an inkjet recording head.

In the twelfth aspect, the static measurement step can be executed also by changing the voltage applied to the piezoelectric element.

A thirteenth aspect of the present invention is any of the eighth to twelfth aspects, in which the voltage applied to the piezoelectric element is
A method of inspecting an ink jet recording head is characterized by applying a piezoelectric of 1/10 or more of a drivable voltage to the piezoelectric element.

In the thirteenth aspect, the characteristic of the actuator device can be identified relatively easily and accurately by applying the predetermined voltage to the piezoelectric element.

A fourteenth aspect of the present invention is the piezoelectric element layer according to any one of the eighth to thirteenth aspects, wherein the piezoelectric element is composed of a lower piezoelectric layer and an upper piezoelectric layer laminated on each other. ,
An individual electrode provided between the lower piezoelectric layer and the upper piezoelectric layer and independent for each piezoelectric element, and provided between the diaphragm and the lower piezoelectric layer and common to a plurality of piezoelectric elements And a common upper electrode that is provided on the upper piezoelectric layer and is electrically connected to the common lower electrode. .

In the fourteenth aspect, the displacement characteristics of the piezoelectric element and the diaphragm can be accurately identified even when the piezoelectric element has a piezoelectric layer composed of a plurality of layers.

[0036]

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 outline of an ink jet recording head according to Embodiment 1 of the present invention, FIG. 2 is a sectional view thereof, and FIG. FIG. 3 is a sectional view in the longitudinal direction of the chamber, FIG. 3B is an enlarged sectional view in the width direction of the pressure generating chamber, and FIG. 3 is a plan view of the ink jet recording head.

As shown in the figure, the ink jet recording head 10 of this embodiment comprises a plurality of, for example, four actuator units 20 and one flow path unit 30 to which these four actuator units 20 are fixed. Has been done.

Each actuator unit 20 is an actuator device having a piezoelectric element 40, and includes a flow path forming substrate 22 in which a pressure generating chamber 21 is formed, and a vibrating plate 23 provided on one side of the flow path forming substrate 22. And a pressure generating chamber bottom plate 24 provided on the other surface side of the flow path forming substrate 22.

The flow path forming substrate 22 is, for example, 150 μm
It is made of a ceramic plate such as zirconia (ZrO ₂ ) having a certain thickness, and in this embodiment, a plurality of pressure generating chambers 21 are arranged in parallel in the width direction to form two rows. Then, on one surface of the flow path forming substrate 22,
For example, a vibrating plate 23 made of a zirconia thin plate having a thickness of 10 μm is fixed, and one surface of the pressure generating chamber 21 is sealed by the vibrating plate 23.

The pressure generating chamber bottom plate 24 is the flow path forming substrate 22.
Supply that is fixed to the other surface side of the pressure generating chamber 21 to seal the other surface of the pressure generating chamber 21 and that is provided in the vicinity of one end of the pressure generating chamber 21 in the longitudinal direction to communicate the pressure generating chamber 21 with a reservoir described later. It has a communication hole 25 and a nozzle communication hole 26 which is provided in the vicinity of the end portion of the pressure generating chamber 21 on the other side in the longitudinal direction and communicates with a nozzle opening 34 described later.

The piezoelectric element 40 is provided in each of the regions on the vibrating plate 23 facing the pressure generating chambers 21. For example, in this embodiment, the pressure generating chambers 21 are arranged in two rows.
Since the piezoelectric elements 40 are provided in two rows, the piezoelectric elements 40 are also provided in two rows.

Here, each piezoelectric element 40 has a piezoelectric layer 46 composed of a lower piezoelectric layer 44 and an upper piezoelectric layer 45 laminated on each other, and a common lower electrode common to a plurality of piezoelectric elements 40. 47 and a common upper electrode 48, and a drive electrode 49 serving as an individual electrode of each piezoelectric element 40.

That is, a common lower electrode 47 common to the plurality of piezoelectric elements 40 is formed on the surface of the vibration plate 23, and on the common lower electrode 47, the lower piezoelectric layer 44 independent for each pressure generating chamber 21 is formed. And the upper piezoelectric layer 45 are sequentially laminated. A drive electrode 49 which is an individual electrode of each piezoelectric element 40 is formed between the lower piezoelectric layer 44 and the upper piezoelectric layer 45. A common upper electrode 48 common to a plurality of piezoelectric elements is formed on the upper piezoelectric layer 45, and the common upper electrode 48 and the common lower electrode 47 are wire-bonded,
Alternatively, it is conducted by soldering or the like.

In such a piezoelectric element 40, since the lower piezoelectric layer 44 and the upper piezoelectric layer 45 have different polarization directions, a space between the drive electrode 49 and the common lower electrode 47 and the common upper electrode 48 is provided. When a voltage is applied at the same time, the lower piezoelectric layer 44
The upper piezoelectric layer 45 is flexibly deformed in the same direction to deform the vibrating plate 23 and apply pressure to the pressure generating chamber 21.

The actuator unit 20 as described above includes the ceramic flow path forming substrate 22 and the vibrating plate 2.
3 and each member of the pressure generating chamber bottom plate 24 are laminated and sintered to be integrated, and then the piezoelectric element 40 is formed on the vibrating plate 23. The method of forming the piezoelectric element 40 will be described later in detail.

On the other hand, the flow path unit 30 is provided with an ink supply port forming substrate 31 joined to the pressure generating chamber bottom plate 24 of the actuator unit 20 and a reservoir 32 serving as a common ink chamber for the plurality of pressure generating chambers 21. It comprises a reservoir forming substrate 33 and a nozzle plate 35 having nozzle openings 34 formed therein. And this flow path unit 30 is
In this embodiment, four actuator units 20 are formed so that they can be fixed.

The ink supply port forming substrate 31 has a thickness of 150.
A nozzle communication hole 36, which is made of a zirconia thin plate having a thickness of μm, connects the nozzle opening 34 and the pressure generating chamber 21, and an ink supply port 37 that connects the reservoir 32 and the pressure generating chamber 21 together with the supply communication hole 25 described above. In addition, an ink introduction port 38 that is connected to each reservoir 32 and supplies ink from an external ink tank is provided.

The reservoir forming substrate 33 is a plate material suitable for forming an ink flow path and having a corrosion resistance such as 150 μm of stainless steel, and is supplied with ink from an external ink tank (not shown) to apply pressure. It has a reservoir 32 that supplies ink to the generation chamber 21, and a nozzle communication hole 39 that connects the pressure generation chamber 21 and the nozzle opening 34.

The nozzle plate 35 is formed, for example, on a thin plate made of stainless steel by forming nozzle openings 34 at the same arrangement pitch as the pressure generating chambers 21. For example, in the present embodiment, since the four actuator units 20 are fixed to the flow path unit 30, the nozzle plate 35 has eight rows of nozzle openings 34. The nozzle plate 35 is bonded to the surface of the reservoir forming substrate 33 opposite to the flow passage forming substrate 22 to seal one surface of the reservoir 32.

The flow path unit 30 is formed by bonding the ink supply port forming substrate 31, the reservoir forming substrate 33 and the nozzle plate 35 with an adhesive. Although the reservoir forming substrate 33 and the nozzle plate 35 are formed of stainless steel in this embodiment, they are formed of, for example, ceramics, and the passage unit 30 is integrally formed like the actuator unit 20. You can also

A predetermined number of such flow passage units 30, that is, four actuator units 20 are provided.
The ink jet recording head 10 of the present embodiment is formed by joining the above.

Now, a method of manufacturing an ink jet recording head, particularly a method of manufacturing an actuator unit, will be described in detail in this embodiment.

First, the flow path forming substrate 22, the vibrating plate 23 and the pressure generating chamber bottom plate 24, which are formed in a predetermined shape, are integrated by firing to form a bonded body, and then, as shown in FIG. The common lower electrode 47 is formed on the surface of the plate 23. In this embodiment, the common lower electrode 47 is formed by applying the common lower electrode 47 by printing and then firing. That is, a mask is placed at a predetermined position on the diaphragm 23, and platinum paste is applied to the surface of the diaphragm 23 through this mask. Then, after the platinum paste is applied by printing in this manner, the joined body to which the platinum paste is applied is placed in a firing furnace and fired at a predetermined temperature for a predetermined time. By this firing, the surface of the diaphragm 23 has a predetermined shape, in the present embodiment,
The comb-shaped common lower electrode 47 is formed.

As the material of the common lower electrode 47, various conductors such as a simple metal, an alloy, an alloy of electrically insulating ceramics and a metal can be used, but there is no problem such as alteration at the firing temperature. Preferably, for example, platinum is used in this embodiment. The common upper electrode 48 and the drive electrode 49 may be made of the same material as the common lower electrode 47. For example, in the present embodiment, gold is used for the common upper electrode 48 and platinum is used for the drive electrode 49. There is.

Next, as shown in FIG. 4B, the lower piezoelectric layer 44 is formed. That is, after a mask is placed at a predetermined position on the vibration plate 23, a paste of a piezoelectric material (for example, lead zirconate titanate) is overlaid on the common lower electrode 47 and applied. Then, the applied piezoelectric material in paste form is fired to form the lower piezoelectric layer 44.

Thereafter, the driving electrode 49,
The upper piezoelectric layer 45 and the common upper electrode 48 are sequentially formed. That is, as shown in FIG. 4C, the drive electrode 4 is formed by applying and baking platinum paste on the lower piezoelectric layer 44.
9 is formed, and as shown in FIG. 4D, an upper piezoelectric layer 45 is formed by applying a paste of a piezoelectric material on the lower piezoelectric layer 44 so as to cover the drive electrode 49 and baking the paste. Further, as shown in FIG. 4E, a common upper electrode 48 is formed by applying a gold paste on the surface of the upper piezoelectric layer 45 and firing it.

Although not shown, the actuator unit 20 is formed by electrically connecting the common lower electrode 47 and the common upper electrode 48 by wire bonding, soldering, or the like.

When the actuator unit 20 is formed in this manner, next, an inspection process is performed to inspect that each layer forming the piezoelectric element 40 is normally produced and to identify its characteristics. In the present embodiment, the characteristics of the actuator unit 20 are identified by measuring the capacitance of each piezoelectric element 40, which has a correlation with the dimension (for example, thickness or width) of the piezoelectric layer 46. Specifically, the piezoelectric elements 40 when a voltage is applied to each piezoelectric element 40
And the variation of the displacement amount of the diaphragm 23 is identified.

In such an inspection process, each piezoelectric element 40
At least a drive measurement step of applying a predetermined voltage having a frequency at which the piezoelectric layer 46 can be driven to the piezoelectric layer 46 to measure the capacitance of the piezoelectric layer 46. That is, in this drive measurement step, the piezoelectric element 40 is moved under the condition that the piezoelectric element 40 is slightly displaced.
A voltage is applied to and the characteristic change of the piezoelectric layer 46 at that time is measured. Then, based on this measurement result, the degree of variation in the displacement amount of each piezoelectric element 40 and the diaphragm 23 is identified.

For example, in this embodiment, 1/10 of the voltage at which the piezoelectric element 40 can be driven at a frequency lower than the resonance frequency of the piezoelectric layer 46, preferably at a frequency of 3 kHz or less.
By applying the above voltage, for example, a voltage of about 5 V, the change with time of the capacitance of each piezoelectric layer 46 is measured, and based on the measurement result, each piezoelectric element 40 and the diaphragm 23 are measured.
The degree of variation in the amount of displacement is identified.

In this embodiment, each piezoelectric element 40
Is a common lower electrode 47 and a common upper electrode 4 as shown in FIG.
8 is electrically connected to the drive electrode 49 and the common lower electrode 4
7 or the common upper electrode 48, if the capacitance is measured, it is necessary to measure the total capacitance of the entire piezoelectric layer 46, that is, the lower piezoelectric layer 44 and the upper piezoelectric layer 45. become.

As described above, the characteristics of the actuator unit 20 can be reliably identified by measuring the electrostatic capacitance of the piezoelectric layer 46 while actually displacing the piezoelectric element 40. That is, not only the characteristic variation caused by the difference in the electrostatic capacitance of the piezoelectric layer 46 itself but also other factors, for example, the characteristic variation of the actuator unit 20 due to the displacement of the piezoelectric element 40 and the like can be identified.

Further, in the present embodiment, a static measurement step of applying a predetermined voltage having a frequency not driving the piezoelectric element 40 to the piezoelectric element 40 and measuring the capacitance of the piezoelectric layer 46 at that time is further executed. Then, the characteristics of the actuator unit 20 are identified based on the measurement results of the drive measurement process and the static measurement process.

In this static measurement step, specifically, a frequency higher than the resonance frequency of the piezoelectric element 40, preferably 1
A predetermined voltage having a frequency of 0 kHz or higher is applied to the piezoelectric layer 46, and the capacitance of the piezoelectric layer 46 is measured. That is,
In the static measurement step, the electrostatic capacitance of the piezoelectric layer 46 when the piezoelectric element 40 is stationary is measured.

By performing such a static measurement step, it is possible to ensure the variation in the characteristics of the actuator unit 20 due to the difference in the capacitance of the piezoelectric layer 46 itself, that is, the variation in the displacement characteristics of each piezoelectric element 40. Can be identified. Then, the characteristics of the actuator unit 20 can be identified extremely accurately by referring to the measurement results of the drive measurement step and the static measurement step.

In this embodiment, in the static measurement step, the capacitance of the piezoelectric layer 46 is measured by applying a predetermined voltage having a frequency higher than the resonance frequency of the piezoelectric element 40. There is no limitation, and for example, the piezoelectric element 40
Even if the frequency is lower than the resonance frequency of
0 is applied to the piezoelectric layer 4 by applying a low voltage that does not drive it.
The capacitance of 6 may be measured. In any case, in the static measurement step, a voltage may be applied under the condition that the piezoelectric element 40 is not driven and the capacitance of the piezoelectric layer 46 may be measured.

When such an inspection process is completed, each actuator unit 2 is based on the measurement result.
It is determined whether 0 is a non-defective product or a defective product, and the actuator unit 20 determined to be a non-defective product is classified based on the measurement result. For example, the ranking based on the average capacitance of each actuator unit 20 or the ranking based on the variation range of the capacitance is performed. For example, in the present embodiment, the rank is divided into 10 levels based on the average capacitance.

In this embodiment, the resonance frequency of each piezoelectric element 40 is used, for example, to divide the rank into four stages. Therefore, each actuator unit 20
Are ranked in 40 steps.

After classifying the actuator units 20 in this manner, a polarization step of polarizing each piezoelectric element 40 is performed. In this polarization step, for example, the common upper electrode 48 and the common lower electrode 47 are grounded, the drive electrode 49 is connected to a power source, and a voltage (polarization voltage) sufficiently higher than the drive voltage to be used is applied to the piezoelectric element 40. It is done by doing. In the present embodiment, the drive voltage is around 30V and the polarization voltage is set around 70V. After the polarization process is completed, the ink jet recording head 10 is formed by selecting the actuator units 20 of the same rank and adhering them to the flow path unit 30.

As described above, in the present embodiment, since the actuator unit that has undergone the above-described inspection process is mounted on the ink jet recording head, desired ink ejection characteristics can be surely obtained and the yield is remarkably improved. . Further, since the inkjet recording head 10 is formed by combining the actuators 20 of the same rank, by supplying the same drive waveform to each piezoelectric element 40, the same ink ejection characteristic is obtained from each nozzle opening 34. Ink droplets can be ejected, and the print quality is greatly improved.

(Other Embodiments) Although one embodiment of the present invention has been described above, the configuration of the present invention is not limited to the above.

For example, in the above-mentioned embodiment, the piezoelectric element has been described by exemplifying one having a piezoelectric layer composed of a plurality of layers (a lower piezoelectric layer and an upper piezoelectric layer), but the present invention is not limited to this. Of course, the piezoelectric element may have one piezoelectric layer.

Further, for example, in the above-described embodiment, four actuator units are fixed to one flow path unit, but of course, one actuator unit is fixed to one flow path unit. Good.

Further, in the above embodiment, the ink jet type recording head provided with the actuator device has been described, but the present invention is, for example, an actuator device mounted on a liquid ejecting device such as a liquid crystal ejecting head or a color material ejecting head. Can also be applied to.

[0076]

As described above, according to the present invention, a predetermined voltage is applied to the piezoelectric element under the condition that the piezoelectric element can be driven, that is, the characteristics of the actuator device are identified while the piezoelectric element is slightly driven. Therefore, the characteristics of the actuator device can be identified very accurately.

[Brief description of drawings]

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

FIG. 2 is a sectional view of the ink jet recording head according to the first embodiment of the invention.

FIG. 3 is a plan view 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 piezoelectric element according to the first embodiment of the present invention.

FIG. 5 is a sectional view illustrating the outline of the inspection process according to the first embodiment of the present invention.

[Explanation of symbols]

10 Inkjet recording head 20 actuator unit 21 Pressure generation chamber 22 Flow path forming substrate 23 diaphragm 24 Pressure generation chamber bottom plate 30 flow path unit 31 Ink supply port forming substrate 32 reservoir 33 Reservoir formation substrate 34 nozzle opening 35 nozzle plate 40 Piezoelectric element 44 Lower piezoelectric layer 45 Upper piezoelectric layer 46 Piezoelectric layer 47 Common lower electrode 48 common upper electrode 49 Drive electrode

Claims (14)

[Claims] 1. A flow path forming substrate in which a pressure generating chamber is formed, and a piezoelectric element provided in a region opposite to the pressure generating chamber on one surface side of the flow path forming substrate via a vibration plate. A method of inspecting an actuator device for causing a pressure change in the pressure generating chamber by flexibly displacing the piezoelectric element, wherein a predetermined voltage is applied to the piezoelectric element under a condition in which the piezoelectric element can be driven, A method for inspecting an actuator device, which comprises identifying a characteristic of the piezoelectric layer by performing at least a drive measurement step of measuring a capacitance of the piezoelectric layer. 2. The method for inspecting an actuator device according to claim 1, wherein in the drive measuring step, a predetermined voltage having a frequency lower than a resonance frequency of the piezoelectric element is applied to the piezoelectric element. 3. The drive measurement according to claim 1, further comprising a static measurement step of measuring a capacitance of the piezoelectric layer by applying a predetermined voltage at a frequency that does not drive the piezoelectric element. A method for inspecting an actuator device, wherein the characteristics of the actuator device are identified based on the measurement results of the process and the static measurement process. 4. The method of inspecting an actuator device according to claim 3, wherein in the static measurement step, a predetermined voltage having a frequency higher than a resonance frequency of the piezoelectric layer is applied to the piezoelectric element. 5. The inspection method for an actuator device according to claim 3, wherein in the static measurement step, a voltage having a frequency lower than a resonance frequency of the piezoelectric element and not driving the piezoelectric element is applied. . 6. The method for inspecting an actuator device according to claim 1, wherein a voltage applied to the piezoelectric element is 1/10 or more of a drivable voltage of the piezoelectric element. 7. The piezoelectric element according to claim 1, wherein the piezoelectric element is composed of a lower piezoelectric layer and an upper piezoelectric layer which are laminated on each other, and the lower piezoelectric layer and the upper piezoelectric layer. An individual electrode provided between the piezoelectric layer and independent for each piezoelectric element; a common lower electrode provided between the vibration plate and the lower piezoelectric layer and common to a plurality of piezoelectric elements; A method for inspecting an actuator device, comprising: a common upper electrode provided on the upper piezoelectric layer and electrically connected to the common lower electrode. 8. A flow path forming substrate in which a pressure generating chamber communicating with the nozzle opening is formed, and a region facing the pressure generating chamber on one surface side of the flow path forming substrate is provided via a vibration plate. A method for inspecting an ink jet recording head, comprising: an actuator device having a piezoelectric element, wherein the piezoelectric element is flexibly displaced to generate a pressure change in the pressure generating chamber to eject an ink droplet from the nozzle opening. A characteristic is identified by performing at least a drive measurement step of applying a predetermined voltage to the piezoelectric element under a condition in which the piezoelectric element can be driven to measure the capacitance of the piezoelectric layer. Method for inspecting inkjet recording head. 9. The method for inspecting an ink jet recording head according to claim 8, wherein in the drive measuring step, a predetermined voltage having a frequency lower than a resonance frequency of the piezoelectric layer is applied to the piezoelectric element. 10. The static measurement step according to claim 8 or 9, further comprising applying a predetermined voltage to the piezoelectric element at a frequency at which the piezoelectric element is not driven to measure the capacitance of the piezoelectric layer. A method for inspecting an ink jet recording head, characterized in that its characteristics are identified based on the measurement results of the drive measurement step and the stationary measurement step. 11. The method for inspecting an ink jet recording head according to claim 10, wherein in the static measurement step, a predetermined voltage having a frequency higher than a resonance frequency of the piezoelectric layer is applied to the piezoelectric element. 12. The ink jet recording head according to claim 10, wherein in the static measurement step, a voltage having a frequency lower than a resonance frequency of the piezoelectric element and not driving the piezoelectric element is applied. Inspection method. 13. The ink jet recording head according to claim 8, wherein a voltage applied to the piezoelectric element is a piezoelectric that is 1/10 or more of a drivable voltage of the piezoelectric element. Inspection method. 14. The piezoelectric layer according to claim 8, wherein the piezoelectric element is composed of a lower piezoelectric layer and an upper piezoelectric layer that are stacked on each other, and the lower piezoelectric layer and the upper piezoelectric layer. An individual electrode provided between the piezoelectric layer and independent for each piezoelectric element; a common lower electrode provided between the vibration plate and the lower piezoelectric layer and common to a plurality of piezoelectric elements; A method of inspecting an ink jet recording head, comprising: a common upper electrode provided on the upper piezoelectric layer and electrically connected to the common lower electrode.