JP2006060127A - Actuator, ink-jet recording head, ink-jet printer, actuator pump, and method for manufacturing actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator having an electrostrictive polymer film whose amount of displacement is large. <P>SOLUTION: This actuator contains a substrate, a lower electrode formed above the substrate, the electrostrictive polymer film formed above the lower electrode, and an upper electrode formed above the electrostrictive polymer film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an actuator having an electrostrictive polymer film, a manufacturing method thereof, an ink jet recording head, an ink jet printer, and an actuator pump.

  Conventionally, as an actuator for controlling a fluid, there are, for example, a piezoelectric element using a ceramic material, an electromagnetic force, and an air pressure. However, such an actuator has problems such as small displacement and large energy consumption.

  An ink jet printer is known as an application device using such an actuator. The ink jet printer includes an ink jet recording head having a cavity whose internal volume changes. An ink jet printer performs printing by ejecting ink droplets from its nozzles while scanning an ink jet recording head.

  In recent years, there has been a demand for higher image quality in such inkjet printers. In order to meet such demands, it has become an indispensable technique to increase the density of nozzles in an ink jet recording head.

Conventionally, as a head actuator in an ink jet recording head for an ink jet printer, a piezoelectric element using a piezoelectric film typified by PZT (Pb (Zr, Ti) O ₃ ) has been used (for example, Japanese Patent Laid-Open No. 2001). -223404).

  However, when the cavity is made small in order to increase the density of the nozzles in the ink jet recording head, the amount of change in the internal volume of the cavity becomes insufficient due to the limited amount of displacement in the piezoelectric element, and the ink ejection performance is reduced. It may get worse.

In addition, since improvement in the characteristics of the piezoelectric pump is also desired, it is desired to provide a good pump using a new material.
JP 2001-223404 A

  An object of the present invention is to provide an actuator having a large displacement and a method for manufacturing the actuator. Another object of the present invention is to provide an ink jet recording head, an ink jet printer, and an actuator pump using the actuator.

The actuator according to the present invention is
A substrate,
A lower electrode formed above the substrate;
An electrostrictive polymer film formed above the lower electrode;
An upper electrode formed above the electrostrictive polymer film.

The actuator according to the present invention is
An elastic body film may be formed above the substrate and below the lower electrode.

  In the actuator according to the present invention, the elastic film may have a hard film containing at least one of yttria-stabilized zirconia, cerium oxide, zirconium oxide, and a solid solution containing these.

  In the actuator according to the present invention, the elastic film can include a silicon oxide film.

  In the actuator according to the present invention, the substrate may be made of single crystal silicon.

  In the actuator according to the present invention, the lower electrode may be made of a conductive polymer.

  In the actuator according to the present invention, the upper electrode may be made of a conductive polymer.

  In the actuator according to the present invention, the electrostrictive polymer film may be made of at least one of silicone rubber, polyurethane, fluoroelastomer, and polybutadiene.

  An ink jet recording head according to the present invention has the actuator described above.

  An ink jet printer according to the present invention has the above-described ink jet recording head.

  The actuator pump according to the present invention has the above-described actuator.

The manufacturing method of the actuator according to the present invention includes:
(A) applying a solution containing the material of the lower electrode above the substrate and performing a heat treatment to form the lower electrode;
(B) applying a solution containing an electrostrictive polymer above the lower electrode and performing a heat treatment to form an electrostrictive polymer film;
(C) applying a solution containing the material of the upper electrode above the electrostrictive polymer film and heat-treating to form an upper electrode;
including.

  In the actuator manufacturing method according to the present invention, at least one of the steps (a) to (c), the solution can be applied by a droplet discharge method.

  In the method for manufacturing an actuator according to the present invention, before the step (a), the step of thermally oxidizing at least the surface of the substrate made of silicon to form an elastic film made of silicon oxide on the substrate; Can further be included.

  In the method for manufacturing an actuator according to the present invention, the solution containing the material of the upper electrode may be a liquid containing metal fine particles or a solution containing a conductive polymer.

  In the method for manufacturing an actuator according to the present invention, the solution containing the material of the lower electrode may be a liquid containing metal fine particles or a solution containing a conductive polymer.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

1.1. Actuator FIG. 1 is a sectional view showing an actuator according to the present embodiment. The actuator 1 includes a silicon substrate 2, a silicon oxide film 3 formed on the silicon substrate 2, a hard film 4 formed on the silicon oxide film 3, a lower electrode 5 formed on the hard film 4, An electrostrictive polymer film 6 formed on the lower electrode 5 and an upper electrode 7 formed on the electrostrictive polymer film 6 are included. In the present embodiment, the elastic film 8 includes the silicon oxide film 3 and the hard film 4.

  The material of the electrostrictive polymer film 6 is an electrostrictive polymer that is compressed in the film thickness direction when a voltage is applied and extends in the plane direction. For example, at least one of silicone rubber, polyurethane, fluoroelastomer, and polybutadiene is used. It consists of seeds. Thereby, the electrostrictive polymer film 6 has a function of expanding in a direction parallel to the surface of the film and contracting in a direction perpendicular to the surface when a voltage is applied. As a result, the electrostrictive polymer film 6 bends downward in the figure when a voltage is applied.

  The material of the elastic film 8 is preferably made of a material harder than the electrostrictive polymer film 6. The electrostrictive polymer film 6 is made of a soft electrostrictive polymer. By providing the elastic film 8 made of a material harder than the electrostrictive polymer film 6, the actuator 1 can improve the fluid controllability compared to the case where the elastic film 8 is not provided. Therefore, for example, when such an actuator 1 is used in an ink jet recording head, the ink ejection speed can be improved.

  The elastic film 8 may be formed of only one of the silicon oxide film 3 and the hard film 4. For example, when the elastic film 8 is formed only of the silicon oxide film 3, the elastic film 8 can be formed by oxidizing the silicon substrate 2, so that the manufacturing process can be simplified. . When the elastic body film 8 has both the silicon oxide film 3 and the hard film 4, the fluid controllability is higher than when the elastic body film 8 has only one of the silicon oxide film 3 and the hard film 4. Can be improved.

  As the silicon substrate 2, for example, a (100) -oriented or (110) -oriented single crystal silicon substrate is used. The silicon oxide film 3 is a film obtained by oxidizing the silicon substrate 2 as described above. The hard film 4 is made of at least one of yttria-stabilized zirconia, cerium oxide, zirconium oxide, and a solid solution containing these.

  The lower electrode 5 is one electrode for applying a voltage to the electrostrictive polymer film 6. As the material of the lower electrode 5, a metal such as Pt, Ir, Ru, Cu, Al, Au, or Ag, or a conductive polymer such as polyethylene dioxane thiophene (hereinafter PEDOT) or polyaniline is used.

  The upper electrode 7 is the other electrode for applying a voltage to the electrostrictive polymer film 6. As the material of the upper electrode 7, for example, metal Pt, Ir, Ru, Cu, Al, Au, Ag, or a conductive polymer such as polyethylene dioxane thiophene (hereinafter PEDOT) or polyaniline is used as in the lower electrode 5. it can.

  As a material for the lower electrode 5 and the upper electrode 7, a conductive polymer is preferably used. Since the electrode using the conductive polymer is softer than the electrode using the metal, the electrostrictive polymer film 6 can be bent at the same time as it is bent. Moreover, since the electrode using a conductive polymer is soft, the actuator 1 having such an electrode has good operability.

1.2. Next, a method for manufacturing the actuator 1 according to the present embodiment will be described.

  (1) First, as the silicon substrate 2, a (100) -oriented or (110) -oriented single crystal silicon substrate is prepared.

  (2) Next, as shown in FIG. 2, a silicon oxide film 3 is formed on the silicon substrate 2. The silicon oxide film 3 is obtained, for example, by thermally oxidizing the surface of the silicon substrate 2.

  (3) Next, as shown in FIG. 3, a hard film 4 is formed on the silicon oxide film 3. As a method for forming the hard film 4, a vapor phase method such as a CVD method, a sputtering method, or a vapor deposition method is appropriately employed depending on the material to be formed.

  (4) Next, as shown in FIG. 4, the lower electrode 5 is formed on the hard film 4. The lower electrode 5 is formed by applying a liquid containing metal fine particles in which metal fine particles are dispersed in a solvent or a liquid containing a conductive polymer on the hard film 4 and drying by applying heat. Examples of the method for applying the liquid onto the hard film 4 include a spin coating method and a droplet discharge method. Examples of the droplet discharge method include an inkjet method. Further, as a method of forming the lower electrode 5 using a metal, a sputtering method, a vapor deposition method, or the like can be used.

  (5) Next, as shown in FIG. 5, an electrostrictive polymer film 6 is formed on the lower electrode 5. The electrostrictive polymer film 6 is formed by applying a solution containing an electrostrictive polymer to the surface of the lower electrode 5, heat-treating, and drying. Examples of the method for applying the solution include droplet discharge methods such as spin coating, dip coating, and ink jet method.

  (6) Next, as shown in FIG. 1, the upper electrode 7 is formed on the electrostrictive polymer film 6. The upper electrode 7 is formed by applying a liquid containing metal fine particles in which metal fine particles are dispersed in a solvent or a liquid containing a conductive polymer on the hard film 4, heat-treating, and drying. Examples of the method for applying the liquid onto the hard film 4 include a spin coating method and a droplet discharge method. The particle diameter of the metal fine particles contained in the solution to be applied is preferably 50 nm or more and 0.1 μm or less from the viewpoint of ease of dispersion in a solvent and application of the inkjet method.

1.3. Action and Effect of Actuator Since the actuator 1 according to the present embodiment is formed using an electrostrictive polymer, the displacement is large and the energy consumption is small, so that the fluid can be controlled efficiently. The actuator 1 includes a silicon oxide film 3 and a hard film 4 that are elastic films 8. Thereby, when the actuator 1 is used in an ink jet recording head, the ink ejection speed can be improved.

2.1. Inkjet Recording Head Next, an inkjet recording head to which the actuator 1 shown in FIG. 1 is applied will be described. 6 is a side sectional view showing a schematic configuration of an ink jet recording head using the actuator 1 shown in FIG. 1, and FIG. 7 is an exploded perspective view of the ink jet recording head. In addition, FIG. 7 is shown upside down from the state normally used.

  As shown in FIG. 6, an ink jet recording head (hereinafter also referred to as “head”) 50 includes a nozzle plate 51, an ink chamber substrate 52, an elastic plate 55 provided on the ink chamber substrate 52, and an elastic plate. An electrostrictive polymer element 54 provided on 55. The electrostrictive polymer element 54 shown in FIG. 6 includes the electrostrictive polymer film 6 and the upper electrode 7 in the actuator 1 shown in FIG. Further, the elastic plate 55 shown in FIG. 6 includes the silicon oxide film 3, the hard film 4, and the lower electrode 5 in the actuator 1 shown in FIG.

  That is, as shown in FIG. 7, the head 50 includes a nozzle plate 51, an ink chamber substrate 52, an elastic plate 55, and an electrostrictive polymer element (vibration source) 54 joined to the elastic plate 55. Is housed in the base 56. The head 50 constitutes an on-demand piezo jet head.

  The nozzle plate 51 is composed of, for example, a stainless steel rolling plate or the like, and has a large number of nozzles 511 for ejecting ink droplets formed in a line. The pitch between these nozzles 511 is appropriately set according to the printing accuracy.

  An ink chamber substrate 52 is fixed (fixed) to the nozzle plate 51. The ink chamber substrate 52 is formed by the silicon substrate 2 described above. The ink chamber substrate 52 has a plurality of cavities (ink cavities) 521, a reservoir 523, and a supply port 524 formed by a nozzle plate 51, side walls (partition walls) 522, and an elastic plate 55 described later. . The reservoir 523 temporarily stores ink supplied from the ink cartridge 631 (see FIG. 14). Ink is supplied from the reservoir 523 to each cavity 521 through the supply port 524.

  The cavities 521 are each formed in a strip shape. As shown in FIGS. 8 and 9, the planar shape of the cavity 521 is a rectangular shape (parallelogram shape) having a major axis and a minor axis. Typical scales of the major axis and the minor axis of the cavity 521 are 2 mm and 60 μm, respectively. As shown in FIGS. 6 and 7, the cavity 521 is disposed corresponding to each nozzle 511. The cavities 521 each have a variable volume due to vibration of an elastic plate 55 described later. The cavity 521 is configured to eject ink by this volume change.

  The average thickness of the ink chamber substrate 52, that is, the thickness including the cavity 521 is not particularly limited, but is preferably about 10 to 1000 μm, and more preferably about 100 to 500 μm. Further, the volume of the cavity 521 is not particularly limited, but is preferably about 0.1 to 100 nL, and more preferably about 0.1 to 10 nL.

  An elastic plate 55 is disposed on the side of the ink chamber substrate 52 opposite to the nozzle plate 51. Further, a plurality of electrostrictive polymer elements 54 are provided on the side of the elastic plate 55 opposite to the ink chamber substrate 52. As shown in FIG. 7, a communication hole 531 is formed at a predetermined position of the elastic plate 55 so as to penetrate in the thickness direction of the elastic plate 55. Ink is supplied from an ink cartridge 631 to be described later to the reservoir 523 through the communication hole 531.

  Each electrostrictive polymer element 54 includes the electrostrictive polymer film 6 and the upper electrode 7 as described above. As shown in FIG. 9, each electrostrictive polymer element 54 has a rectangular shape in plan view and is disposed corresponding to the substantially central portion of each cavity 521. Each of these electrostrictive polymer elements 54 is electrically connected to a drive circuit, which will be described later, and is configured to operate (vibrate, deform) based on a signal from the drive circuit. That is, each electrostrictive polymer element 54 functions as a vibration source (head actuator). The elastic plate 55 vibrates (deflection) due to the vibration (deflection) of the electrostrictive polymer element 54 and functions to instantaneously increase the internal pressure of the cavity 521.

2.2. Operation of Inkjet Recording Head Next, the operation of the inkjet recording head 50 in the present embodiment will be described. FIG. 10 shows the head 50 in a state where no voltage is applied between the lower electrode 5 and the upper electrode 7.

  As described above in the description of the manufacturing method of the actuator 1, the lower electrode 5, the electrostrictive polymer film 6, and the upper electrode 7 are formed by applying a solution containing a material and drying the solution by heat treatment. Here, as the solvent evaporates and the film contracts, the lower electrode 5, the electrostrictive polymer film 6 and the upper electrode 7 are subjected to compressive stress in the in-plane direction. Due to this stress, even when no voltage is applied, the elastic plate 55, the electrostrictive polymer film 6, and the upper electrode 7 are bent toward the cavity 521 as shown in FIG.

  FIG. 11 shows the head 50 in a state where a voltage is applied between the lower electrode 5 and the upper electrode 7. When a voltage is applied to the electrostrictive polymer film 6, the electrostrictive polymer film 6 extends in a direction parallel to the surface, and thus bends in a direction perpendicular to the surface. Here, as shown in FIG. 10, the electrostrictive polymer film 6 is already bent toward the cavity 521 in a state where no voltage is applied. Therefore, when a voltage is applied, the cavity 521 is applied as shown in FIG. Bend further to the side. As a result, the elastic plate 55 bends and the volume of the cavity 521 changes. At this time, the pressure in the cavity 521 increases instantaneously, and an ink droplet is ejected from the nozzle 511.

  Here, the larger the displacement amount (absolute value) of the electrostrictive polymer film 6 in the cavity 521, the larger the deflection amount of the elastic plate 55, making it possible to eject ink droplets more efficiently. Here, “efficient” means that the same amount of ink droplets can be ejected with a smaller voltage. That is, the driver circuit can be simplified and the power consumption can be reduced at the same time, so that the pitch of the nozzles 511 can be formed with higher density. Alternatively, since the length of the long axis of the cavity 521 can be shortened, the entire head can be reduced in size. Further, when the voltage applied to the electrostrictive polymer film 6 is increased, the amount of deflection of the electrostrictive polymer film 6 is increased. Therefore, the amount of ink droplets ejected by the head 50 can be adjusted by changing the applied voltage.

  When the ejection of one ink is completed, the drive circuit stops applying the voltage between the lower electrode 5 and the upper electrode 7. Thereby, the electrostrictive polymer element 54 returns to the original shape shown in FIG. 10, and the volume of the cavity 521 increases. At this time, the pressure (pressure in the positive direction) from the ink cartridge 631 described later toward the nozzle 511 is applied to the ink. For this reason, air is prevented from entering the cavity 521 from the nozzle 511, and an amount of ink corresponding to the amount of ink discharged is supplied from the ink cartridge 631 to the cavity 521 through the reservoir 523.

  In this manner, arbitrary (desired) characters, figures, etc. are printed by sequentially inputting ejection signals to the electrostrictive polymer film 6 at the position where ink droplet ejection is desired via the drive circuit. be able to.

2.3. Method for Manufacturing Inkjet Recording Head Next, an example of a method for manufacturing the inkjet recording head 50 in the present embodiment will be described.

  (1) First, a base material to be the ink chamber substrate 52 and a silicon substrate 2 made of silicon single crystal are prepared. As the silicon substrate 2, a (110) -oriented or (100) -oriented silicon single crystal substrate is used.

  (2) Next, as shown in FIGS. 2 to 5 and 1, the silicon oxide film 3, the hard film 4, the lower electrode 5, the electrostrictive polymer film 6, and the upper electrode 7 are formed on the silicon substrate 2. Sequentially formed. Here, the electrostrictive polymer film 6 and the upper electrode 7 can be formed in a predetermined pattern using a droplet discharge method. In this embodiment mode, an inkjet method is preferably used as a droplet discharge method. This is because the ink jet method can effectively use materials and can simplify the patterning process as compared with other methods. In particular, the ink jet method can finely adjust the discharge amount and the landing position of droplets, and is therefore suitable for manufacturing an actuator used for an ink jet recording head having high-density nozzles. In this case, before applying the solution, a liquid repellent treatment or a lyophilic treatment may be applied to a predetermined position on the hard film 4 or a bank may be formed. Thereby, a highly accurate pattern of the electrostrictive polymer film 6 can be formed by a simple method.

  (3) Next, as shown in FIG. 12, the electrostrictive polymer film 6 and the upper electrode 7 are processed into a predetermined shape. Specifically, after spin-coating a resist on the upper electrode 7, exposure and development are performed and patterning is performed in accordance with the position where the cavity 521 is to be formed. Using the remaining resist as a mask, the upper electrode 7 and the electrostrictive polymer film 6 are etched by ion milling or the like.

  Here, the lower electrode 5 is one electrode for applying a voltage to the electrostrictive polymer thin film layer 43, and silicon oxide so as to function as a common electrode for a plurality of actuators formed on the ink chamber substrate 20. Although formed in the same region as the film 3 and the hard film 4, it may be formed in the same shape as the electrostrictive polymer film 6 and the upper electrode 7 instead.

  (4) Next, as shown in FIG. 13 and FIG. 7, the base material (silicon substrate 2) to be the ink chamber substrate 52 is then processed (patterned), and cavities are respectively formed at positions corresponding to the electrostrictive polymer elements 54. A recess to be 521 and a recess to be a reservoir 523 and a supply port 524 are formed at predetermined positions.

  Specifically, a mask layer is formed in accordance with the position where the cavity 521, the reservoir 523, and the supply port 524 are to be formed. Next, for example, parallel plate type reactive ion etching, inductively coupled method, electron cyclotron resonance method, helicon wave excitation method, magnetron method, plasma etching method, ion beam etching method or other dry etching, or 5 to 40% by weight Wet etching is performed with a high-concentration alkaline aqueous solution such as potassium hydroxide and tetramethylammonium hydroxide.

  In this embodiment, since a (110) -oriented silicon substrate is used as a base material, wet etching (anisotropic etching) using a high-concentration alkaline aqueous solution is preferably employed. In wet etching with a high concentration aqueous alkali solution, the silicon oxide film 3 can function as an etching stopper. Therefore, the ink chamber substrate 52 can be formed more easily.

  In this way, the ink chamber substrate 52 is formed by removing the base material (silicon substrate 2) by etching until the silicon oxide film 3 is exposed in the thickness direction. At this time, a portion left without being etched becomes the side wall 522. The exposed silicon oxide film 3, hard film 4, and lower electrode 5 are in a state where the function as the elastic plate 55 can be exhibited.

  (5) Next, as shown in FIG. 6, the nozzle plate 51 on which the plurality of nozzles 511 are formed is aligned so that each nozzle 511 corresponds to the recess that becomes each cavity 521, and is joined in that state. . Thereby, a plurality of cavities 521, a reservoir 523, and a plurality of supply ports 524 are formed. For the joining of the nozzle plate 51, for example, an adhesive method using an adhesive or a fusion method may be used. Next, the ink chamber substrate 52 is attached to the base 56.

  Through the above steps, the ink jet recording head 50 according to the present embodiment can be manufactured.

2.4. Action / Effect According to the ink jet recording head 50 according to the present embodiment, as described above, since the electrostrictive polymer is used, the displacement amount is large. Accordingly, it is possible to efficiently discharge ink, and it is possible to increase the density of the nozzles 511. Therefore, high-density printing and high-speed printing are possible. Furthermore, the entire head can be reduced in size. Further, it does not contain harmful substances such as lead used as a material for piezoelectric elements.

3.1. Inkjet Printer Next, an inkjet printer including the above-described inkjet recording head 50 will be described. FIG. 14 is a schematic configuration diagram showing an embodiment in which the inkjet printer 600 of the present invention is applied to a general printer that prints on paper or the like. In the following description, the upper side in FIG. 14 is referred to as “upper part” and the lower side is referred to as “lower part”.

  The ink jet printer 600 includes an apparatus main body 620, has a tray 621 for setting the recording paper P in the upper rear, has a discharge port 622 for discharging the recording paper P in the lower front, and has an operation panel 670 in the upper surface. Have

  The operation panel 670 is composed of, for example, a liquid crystal display, an organic EL display, an LED lamp, and the like. The operation panel 670 includes a display unit (not shown) for displaying an error message and the like, and an operation unit (not shown) including various switches. )).

  Inside the apparatus main body 620, there are mainly a printing apparatus 640 provided with a reciprocating head unit 630, a paper feeding apparatus 650 for feeding the recording paper P one by one to the printing apparatus 640, the printing apparatus 640 and the paper feeding apparatus. A control unit 660 for controlling the 650 is provided.

  Under the control of the control unit 660, the paper feeding device 650 intermittently feeds the recording paper P one by one. The recording paper P that is intermittently fed passes near the lower portion of the head unit 630. At this time, the head unit 630 reciprocates in a direction substantially perpendicular to the feeding direction of the recording paper P, and printing on the recording paper P is performed. That is, the reciprocation of the head unit 630 and the intermittent feeding of the recording paper P are the main scanning and the sub-scanning in printing, and ink jet printing is performed.

  The printing apparatus 640 includes a head unit 630, a carriage motor 641 serving as a drive source for the head unit 630, and a reciprocating mechanism 642 that receives the rotation of the carriage motor 641 to reciprocate the head unit 630.

  The head unit 630 includes an ink jet recording head 50 provided with the above-described many nozzles 511, an ink cartridge 631 for supplying ink to the ink jet recording head 50, an ink jet recording head 50, and an ink cartridge 631 at a lower portion thereof. And a carriage 632 mounted thereon.

  By using an ink cartridge 631 filled with yellow, cyan, magenta, and black (black) inks, full color printing is possible. However, the type and number of ink cartridges are not particularly limited. There may be 5-8 colors or more types and types. The head unit 630 is provided with the ink jet recording head 50 corresponding to each color.

  The reciprocating mechanism 642 includes a carriage guide shaft 643 whose both ends are supported by a frame (not shown), and a timing belt 644 extending in parallel with the carriage guide shaft 643. The carriage 632 is supported by the carriage guide shaft 643 so as to reciprocate and is fixed to a part of the timing belt 644. When the timing belt 644 travels forward and backward through a pulley by the operation of the carriage motor 641, the head unit 630 reciprocates while being guided by the carriage guide shaft 643. During this reciprocation, ink is appropriately discharged from the ink jet recording head 50 and printing on the recording paper P is performed.

  The sheet feeding device 650 includes a sheet feeding motor 651 serving as a driving source thereof, and a sheet feeding roller 652 that rotates by the operation of the sheet feeding motor 651. The paper feed roller 652 includes a driven roller 652 a and a drive roller 652 b that are opposed to each other across the feeding path (recording paper P) of the recording paper P, and the driving roller 652 b is connected to the paper feeding motor 651. Has been. With such a configuration, the paper feed roller 652 can feed a large number of recording sheets P set on the tray 621 one by one toward the printing apparatus 6400. Note that, instead of the tray 621, a configuration in which a paper feed cassette for storing the recording paper P can be detachably mounted can be employed.

  The control unit 660 performs printing by controlling the printing device 640, the paper feeding device 650, and the like based on print data input from a host computer such as a personal computer or a digital camera.

  Although not shown, the control unit 660 mainly stores a memory for storing a control program for controlling each unit, a drive circuit for driving the actuator 1 to control ink ejection timing, and a printing device 640 (carriage motor 641). , A drive circuit for driving the paper feeding device 650 (paper feed motor 651), and a communication circuit for obtaining print data from the host computer, and various controls in each part are electrically connected to these. CPU to perform.

  For example, various sensors capable of detecting a printing environment such as the remaining amount of ink in the ink cartridge 631, the position of the head unit 630, temperature, and humidity are electrically connected to the CPU. The control unit 660 obtains print data via the communication circuit and stores it in the memory. The CPU processes the print data and outputs a drive signal to each drive circuit based on the process data and input data from various sensors. The ink jet recording head 50, the printing device 640, and the paper feeding device 650 are operated by this drive signal. Thus, desired printing is performed on the recording paper P.

3.2. Operation and Effect According to the ink jet printer 600 according to the present embodiment, as described above, since the ink jet recording head 50 capable of increasing the nozzle density with high performance is provided, high density printing and high speed printing can be performed. It becomes possible.

  The ink jet printer 600 of the present invention can also be used as a droplet discharge device used industrially. In that case, as the ink to be ejected (liquid material), various functional materials can be used by adjusting them to an appropriate viscosity with a solvent or a dispersion medium.

4.1. Next, the actuator pump according to the present embodiment will be described with reference to the drawings. 15 and 16 are schematic sectional views of an actuator pump 20 using the actuator 1 shown in FIG. The electrostrictive polymer element 22 shown in FIGS. 15 and 16 includes the lower electrode 5, the electrostrictive polymer film 6, and the upper electrode 7 in the actuator 1 shown in FIG. 1, and the actuator 1 shown in FIG. In FIG. 15 and FIG. 16, the silicon oxide film 3 and the hard film 4 in FIG. Further, the silicon substrate 2 (see FIG. 1) serves as a base 21 that constitutes a main part of the actuator pump 20. The actuator pump 20 includes a base 21, an electrostrictive polymer element 22, a pump chamber 23, a diaphragm 24, a suction side check valve 26a, a discharge side check valve 26b, a suction port 28a, and a discharge port 28b. Including.

4.2. Next, the operation of the above-described actuator pump will be described. First, when a voltage is supplied to the electrostrictive polymer element 22, a voltage is applied in the film thickness direction of the electrostrictive polymer film 6 (see FIG. 1). And as shown in FIG. 15, the electrostrictive polymer element 22 bends in the direction (direction of arrow a shown in FIG. 15) where the pump chamber 23 spreads. Further, the diaphragm 24 together with the electrostrictive polymer element 22 bends in the direction in which the pump chamber 23 extends. For this reason, the pressure in the pump chamber 23 changes, and the fluid flows from the suction port 28a into the pump chamber 23 by the action of the check valves 26a and 26b (in the direction of arrow b shown in FIG. 15).

  Next, when the supply of voltage to the electrostrictive polymer element 22 is stopped, the application of voltage in the film thickness direction of the electrostrictive polymer film 6 (see FIG. 1) is stopped. And as shown in FIG. 16, the electrostrictive polymer element 22 bends in the direction (direction of arrow a shown in FIG. 16) where the pump chamber 23 narrows. Further, the diaphragm 24 as well as the electrostrictive polymer element 22 bends in the direction in which the pump chamber 23 is narrowed. For this reason, the pressure in the pump chamber 23 changes, and the fluid is discharged from the discharge port 28b to the outside by the action of the check valves 26a and 26b (in the direction of arrow b shown in FIG. 16).

  The drive voltage of the actuator pump 20 can be about 100 V (AC), for example. Moreover, the drive frequency of the actuator pump 20 can be set to about several tens Hz to several tens kHz, for example.

  The actuator pump 20 can be used as a water cooling module for electronic equipment, for example, a personal computer, preferably a notebook personal computer. The water cooling module uses the above-described actuator pump 20 for driving the coolant, and has a structure including the actuator pump 20 and a circulating water channel.

4.3. Operation and Effect According to the actuator pump 20 according to the present embodiment, as described above, since it is formed using the electrostrictive polymer, the displacement amount is large. Therefore, the fluid can be sucked and discharged efficiently. Therefore, the actuator pump 20 according to the present embodiment can have a large discharge pressure and discharge amount. In addition, the actuator pump 20 can be operated at high speed. Furthermore, the entire actuator pump 20 can be reduced in size.

Sectional drawing which shows the actuator concerning this Embodiment. Sectional drawing which shows the manufacturing process of an actuator. Sectional drawing which shows the manufacturing process of an actuator. Sectional drawing which shows the manufacturing process of an actuator. Sectional drawing which shows the manufacturing process of an actuator. 1 is a schematic configuration diagram of an ink jet recording head. FIG. 2 is an exploded perspective view of an ink jet recording head. The top view of a cavity. The top view of an electrostrictive polymer element. FIG. 4 is a diagram for explaining the operation of an ink jet recording head. FIG. 4 is a diagram for explaining the operation of an ink jet recording head. FIG. 4 is a diagram illustrating a manufacturing process of an ink jet recording head. FIG. 4 is a diagram illustrating a manufacturing process of an ink jet recording head. 1 is a schematic configuration diagram of an ink jet printer according to an embodiment. The schematic sectional drawing of the actuator pump using the actuator shown in FIG. The schematic sectional drawing of the actuator pump using the actuator shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Actuator, 2 Silicon substrate, 3 Silicon oxide film, 4 Hard film, 5 Lower electrode, 6 Electrostrictive polymer film, 7 Upper electrode, 20 Actuator pump, 21 Base, 22 Electrostrictive polymer element, 23 Pump chamber, 24 Diaphragm 50, ink jet recording head, 51 nozzle plate, 52 ink chamber substrate, 54 electrostrictive polymer element, 55 elastic plate, 56 base, 511 nozzle, 521 cavity, 522 side wall, 523 reservoir, 524 supply port, 531 communication hole, 600 Inkjet printer, 620 device main body, 621 tray, 622 discharge port, 630 head unit, 631 ink cartridge, 632 carriage, 640 printing device, 641 carriage motor, 642 reciprocating mechanism, 643 carriage guide shaft, 644 tie Nguberuto, 650 sheet feeding apparatus, 651 a sheet feeding motor, 652 feed roller, 660 control unit, 670 operation panel

Claims (16)

A substrate,
A lower electrode formed above the substrate;
An electrostrictive polymer film formed above the lower electrode;
An upper electrode formed above the electrostrictive polymer film;
Including an actuator. In claim 1,
An actuator comprising an elastic film formed above the substrate and below the lower electrode. In claim 2,
The said elastic body film | membrane is an actuator which has a hard film | membrane containing at least 1 sort (s) among yttria stabilized zirconia, cerium oxide, a zirconium oxide, and the solid solution containing these. In claim 2 or 3,
The actuator is an actuator in which the elastic film includes a silicon oxide film. In claim 4,
The substrate is an actuator made of single crystal silicon. In any of claims 1 to 5,
The lower electrode is an actuator made of a conductive polymer. In any one of Claims 1 thru | or 6.
The upper electrode is an actuator made of a conductive polymer. In any one of Claims 1 thru | or 7,
The electrostrictive polymer film is an actuator comprising at least one of silicone rubber, polyurethane, fluoroelastomer, and polybutadiene.   An ink jet recording head comprising the actuator according to claim 1.   An ink jet printer comprising the ink jet recording head according to claim 9.   An actuator pump comprising the actuator according to claim 1. (A) applying a solution containing the material of the lower electrode above the substrate and performing a heat treatment to form the lower electrode;
(B) applying a solution containing an electrostrictive polymer above the lower electrode and performing a heat treatment to form an electrostrictive polymer film;
(C) applying a solution containing the material of the upper electrode above the electrostrictive polymer film and heat-treating to form an upper electrode;
A method for manufacturing an actuator, comprising: In claim 12,
A method for manufacturing an actuator, wherein in at least one of the steps (a) to (c), the solution is applied by a droplet discharge method. In claim 12 or 13,
Before the step (a),
A method of manufacturing an actuator, further comprising: forming an elastic film made of silicon oxide on the substrate by thermally oxidizing at least a surface of the substrate made of silicon. In any of claims 12 to 14,
The actuator manufacturing method, wherein the solution containing the material of the upper electrode is a liquid containing metal fine particles or a solution containing a conductive polymer. In any of claims 12 to 15,
The method for manufacturing an actuator, wherein the solution containing the material of the lower electrode is a liquid containing metal fine particles or a solution containing a conductive polymer.

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