JP2007336685A - Vibrator, piezoelectric actuator, electronic apparatus, and manufacturing method of vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibrator which can remarkably be reduced in size and easily manufactured, and is prevented from being deteriorated in energy efficiency, and to provide a piezoelectric actuator, an electronic apparatus and a manufacturing method of the vibrator, related to conductive structures of piezoelectric elements. <P>SOLUTION: Electrode patterns 311 to 315 formed at the piezoelectric elements 30A, 30B, respectively, are made to be conductive by conductive patterns 415 to 419 via the side face 20B of the vibrator 20A. These conductive patterns 415 to 419 are formed by making conductive particles contact with one another by drying and solidifying a liquefied substance containing the conductive particles at a normal temperature at a temperature higher than the normal temperature, and thus, this contributes to reduction in size and thickness, an improvement in energy efficiency, and easy manufacturing. Here, it suffices for wiring to be formed from only the side of the piezoelectric element 30A which is arranged on the front side, whereby allowing mounting directions to be aligned in the same directions, making conduction work between the vibrator 20A and an external circuit board easily executable, and allowing the thickness of the vibrator 20A smaller as a whole. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibrating body, a piezoelectric actuator, an electronic device, and a method for manufacturing the vibrating body.

  Piezoelectric elements are excellent in conversion efficiency and responsiveness from electrical energy to mechanical energy, and are suitable for miniaturization and thinning. Therefore, in the field of microelectronics, the vibration of a piezoelectric element due to vibration when an AC voltage is applied to the piezoelectric element. Development of a piezoelectric actuator (ultrasonic motor) for driving a driven body is in progress.

  Here, Patent Document 1 shows an example of a structure of a piezoelectric actuator that is a standing wave system suitable for miniaturization and thinning and has a rectangular vibrating body. The piezoelectric actuator of Patent Document 1 includes two rectangular plate-shaped piezoelectric elements, a conductive reinforcing plate interposed between the piezoelectric elements, a lead substrate that conducts the piezoelectric element and an external substrate, and It is configured with. Each piezoelectric element is polarized in the direction opposite to each other in the thickness direction, and a reinforcing plate to which the back side of each piezoelectric element is joined is used as a common electrode of each piezoelectric element, and the reinforcing plate and the front side of each piezoelectric element are plated or the like. A drive voltage is applied along the polarization direction between each of the formed electrodes, and the piezoelectric elements simultaneously expand and contract due to the piezoelectric lateral effect.

  With regard to conductive mounting in such a piezoelectric actuator, in Patent Document 1 in which a plurality of electrodes are formed on a piezoelectric element, an overhang portion formed on a lead substrate is used, and after all the electrodes are pulled out to the lead substrate at the overhang portion. Continuity in the external circuit. Since each electrode formed on the surface of each piezoelectric element on the front and back sides of the reinforcing plate has substantially the same potential, the lead board provided on the piezoelectric element on the front side of the reinforcing plate and the piezoelectric element on the back side of the reinforcing plate are provided. The lead substrates thus formed are electrically connected to each other and connected to the voltage application device. Here, in Patent Document 1, it is unnecessary to connect the lead substrates by bending one substrate toward both the front and back sides of the vibrating body. And the flexible overhang pattern which protrudes toward the electrode of each piezoelectric element surface from the both ends edge of this bent lead substrate is arrange | positioned, and the front-end | tip of an overhang part is attached to an electrode by heat welding etc. FIG.

Note that wire bonding may be used as shown in FIG. 37 instead of conduction by the overhang pattern. In this case, the same lead substrate 990 can be electrically connected by the wires 993 from the surface electrodes of the piezoelectric elements 991 and 992.
Further, regarding the conductive structure of the piezoelectric actuator, FIG. 16 of Patent Document 2 shows a wire wiring structure, and FIG. 32 of the same document uses a flexible substrate (FPC; flexible printed wiring board). A conducting structure is shown.

Japanese Patent Laying-Open No. 2004-289965 (FIG. 3) WO2003 / 75446 international publication (FIGS. 16 and 32)

However, there is a problem that the thickness of the piezoelectric actuator is increased in the above-described conductive mounting. That is, with reference to FIG. 3B of Patent Document 1, when mounting the lead substrate 46, the overhang portion 461 is arranged so that the overhang portion 461 and the electrode on the surface of the piezoelectric element do not contact each other. The lead substrate 46 needs to be arranged with a predetermined distance from the surface of the piezoelectric element in accordance with the dimensions, and the lead substrate 46 is thickened by such an interval. In particular, it is necessary to set a gap that does not cause an electrical short between the electrode of the piezoelectric element and the conducting portion (wiring) even when subjected to an external impact.
Note that the wire 37 in FIG. 16 in Patent Document 2 and the substrate 15 in FIG. 32 in the same document are also bent in a U-shape on the front surface side and the back surface side of the piezoelectric element, and therefore it is necessary to provide a similar gap. Yes, it gets thick as well.
In addition, as in Patent Documents 1 and 2, when the electrodes on the surface of the piezoelectric element are divided into a plurality, the distance between them prevents the overhang portion from being bent and short-circuited to other electrodes by dropping or vibration. Need to be larger.
In this way, even if only the piezoelectric element on one side of the reinforcing plate is seen, there is a factor that the piezoelectric actuator becomes thick. Since the thickness twice as large as that of the mounting structure is required, the entire piezoelectric actuator is considerably bulky. In addition, a single-plate type piezoelectric actuator composed of only one piezoelectric element also requires a lead substrate for conducting the electrodes on the front surface side and the back surface side. The point that appears and becomes bulky is the same. Piezoelectric actuators are often mounted on small electronic devices because they can provide a large driving force with respect to dimensions such as thickness and length compared to other motors, etc. Further downsizing is desired in the future.
In addition to the problem of the thickness dimension, there is also a problem that the assembling work for joining the overhang portion to the electrode on the surface of the piezoelectric element while maintaining a predetermined distance between the lead substrate and the piezoelectric element is complicated. Furthermore, parts such as spacers and pins for holding such a lead substrate are required, and the assembly work in manufacturing the piezoelectric actuator is complicated and leads to an increase in cost in terms of an increase in the number of parts.

On the other hand, in the mounting structure by wire bonding as shown in FIG. 37 or FIG. 16 of Patent Document 2, the lead substrate 990 can be provided at a position adjacent to the vibrating body in a plane due to the flexibility of the wire 993. Although this has a certain effect of reducing the thickness, the position of the wire 993 is not determined because of its flexibility, or the wire 993 is also separated from the surface of the piezoelectric elements 991, 992 by a predetermined distance due to the rise of the solder. Need to be placed.
In addition, if the wire 993 is thin enough not to affect vibration, its position is very difficult to determine, and it is necessary to set an interval that allows for work variations, so the thickness further increases.
In addition, when the electrode on the surface of the piezoelectric element is divided into a plurality of parts, it is necessary to increase the interval so that the wire is not bent and short-circuited to other electrodes due to dropping or vibration, or two piezoelectric elements are provided. In the case of a case or a single plate type, the thickness is doubled when conducting both front and back, as in the case of the overhang portion.

  In the case of wire bonding, the position of the already bonded wire is determined when holding the side of one piezoelectric element that has already been bonded and performing bonding to the other piezoelectric element on the opposite side. Because of the variation, the area where these wires can reliably hold the piezoelectric element is narrow. For this reason, the piezoelectric element cannot be stably held, and vibration and heat from the bonding tool cannot be reliably transmitted, so that the connection quality of the wire becomes extremely unstable.

  In addition, the bonding wires mentioned above and foils, even overhangs, hinder the vibration of piezoelectric elements due to their drag and solder weight, and these wires and overhangs themselves vibrate separately from the piezoelectric elements. As a result, an unnecessary vibration mode is generated and the energy efficiency of the piezoelectric actuator is lowered. In particular, in the case of a wire, there is a risk of disconnection due to vibration, and there is a concern about a decrease in reliability.

  In view of such a problem, an object of the present invention relates to a conductive structure, a vibration body, a piezoelectric actuator, an electronic device, and a method for manufacturing the vibration body that can be remarkably reduced in size and can be easily manufactured without reducing energy efficiency. It is to provide.

  The vibrating body according to the first aspect of the present invention includes a piezoelectric element that is substantially plate-shaped and has electrodes formed on the front surface portion and the back surface portion, respectively, and a partial electrode is provided on a part of either the front surface portion or the back surface portion. A conductive portion is formed to electrically connect the partial electrode and the electrode formed on the side opposite to the side where the partial electrode is formed through the side surface of the piezoelectric element. A liquid material containing conductive particles at room temperature on the body surface portion of the piezoelectric element including the electrode portion on which the partial electrode and the electrode are formed, and the side surface portion of the piezoelectric element. Then, the liquid particles are dried and solidified at a temperature higher than normal temperature to form the conductive particles in contact with each other.

  The vibrating body according to the second aspect of the present invention is configured by laminating two piezoelectric elements having a substantially plate shape and electrodes formed on at least one of a front surface portion and a back surface portion, and stacking the multilayer body by the piezoelectric elements. The laminate front surface portion and the laminate back surface portion on both ends in the direction are respectively electrode flat portions on which the electrodes are formed, and one of the electrode flat portions, the piezoelectric element side surface portions of the respective piezoelectric elements, and the electrode planes. The body surface portion of the piezoelectric element including the other of the portions is formed with a conductive portion that electrically connects the electrodes in each electrode plane portion to each other, and the conductive portion contains conductive particles at room temperature. After the liquid material is provided on the body surface, the conductive particles are formed in contact with each other by drying and solidifying the liquid material at a temperature higher than room temperature.

According to these first and second inventions, the conductive portion that conducts the electrodes through the side surface portion of the piezoelectric element, and by using such a liquid material, the conductive material is conducted as a thin film along the electrode plane portion and the side surface portion. It is possible to form a portion, and the conductive portion is also integrated with the piezoelectric element in substantially the same manner as the electrode is integrated with the piezoelectric element. For this reason, the piezoelectric element can be significantly reduced in size without increasing the thickness of the piezoelectric element by conducting means such as a wire or an overhang portion. The conduction part formed in this way can provide a conduction structure of a piezoelectric element that is fundamentally different from the conventional one.
Here, since the liquid material is used, it is possible to form a fine conductive pattern that could not be realized in the past, and fine wiring can be realized, so that further miniaturization and thinning can be further promoted.
Further, by drying and solidifying the liquid material on the body surface portion of the piezoelectric element, the position of the conductive portion is not fixed, and the conductive portion is precisely patterned. Furthermore, since the assembly of the conducting portion is unnecessary, the manufacturing becomes extremely easy. Furthermore, since the conductive portion is directly formed in the piezoelectric element in this way, a conventional lead substrate that conducts to the electrode can be eliminated, and a structure for holding such a substrate is also unnecessary. Therefore, it becomes easier to manufacture. In addition, the substrate cost can be reduced and the cost can be reduced.
And there is no possibility that reliability will fall due to wiring and assembly.
Furthermore, since wiring is integrally made with the vibrating body using a liquid material, the planar size of the entire vibrating body and the space occupation necessary for arranging the vibrating body are compared with the configurations described in Patent Documents 1 and 2 above. The area can be downsized. As described above, the gap between the electrode and the (wiring) is not necessary.

In addition, since the conducting portion is integrated into the piezoelectric element as a thin film, the efficiency of mutual conversion between the electrical energy and mechanical energy of the piezoelectric element is good, and the energy efficiency does not decrease. When the piezoelectric element is used for a piezoelectric actuator, since the conducting portion is displaced integrally with the piezoelectric element, the displacement is not hindered by the conducting portion, and driving efficiency is improved.
The use of the vibrating body is not particularly limited, and electronic parts such as an oscillator, a filter, and a transformer, a non-contact measuring device such as an article size and shape, an article displacement measuring apparatus, a living body diagnostic apparatus, and a flow meter It can be widely used as an information device such as a power device such as a processing machine, a treatment device, and a piezoelectric actuator.

  Here, according to the first aspect of the present invention, a partial electrode that is electrically connected to the electrode on the other side is provided on one of the front surface portion and the back surface portion of the piezoelectric element. With respect to the side electrode, wiring may be performed from one side of the piezoelectric element, and the mounting direction can be aligned in the same direction. This facilitates the conductive mounting operation of the piezoelectric element, and it is only necessary to provide a conductive mounting structure for conducting the electrode to an external circuit board or the like on one side, thereby reducing the thickness of the entire piezoelectric element. . Even in the case where the conduction means on one side is an overhang portion connected to the lead substrate, the lead substrate and the overhang portion may be provided on one side of the piezoelectric element, so that the thickness can be reduced. .

Further, according to the second invention, the two piezoelectric elements are electrically connected through the side surface portion of the multilayer body, so that wiring can be performed from one side of the two piezoelectric elements as in the first invention. The direction can be aligned in the same direction. This facilitates the conductive mounting operation of these piezoelectric elements, and it is only necessary to provide a conductive mounting structure on one side of the piezoelectric element for conducting the electrodes formed on the piezoelectric elements to an external circuit board or the like. Therefore, the thickness of the entire vibrating body can be reduced. Even when the conduction means of this one piezoelectric element is an overhang portion connected to the lead substrate, the lead substrate and the overhang portion need only be provided on one surface side of the piezoelectric element. Can be
Furthermore, since the piezoelectric element is provided on both sides of the reinforcing plate, it vibrates stably, and the thickness of each piezoelectric element is suppressed by the conductive portion described above, so that the thickness of the vibrating body can be reduced both front and back. Since the thickness can be reduced, the above-described effect can be increased.

The electrodes of the piezoelectric element can be formed by plating with Au, Ni, etc., sputtering, vapor deposition, or the like.
Moreover, Ag, Au, Cu etc. can be illustrated as a conductive particle which forms a conduction | electrical_connection part.
Here, the liquid substance means a conductive particle dispersion medium, that is, a medium in which conductive particles are dispersed in a medium. This liquid material includes a gel or paste in which conductive particles such as Ag having a particle size of about several μm are dispersed in a medium such as water using an epoxy resin as a dispersant. In addition, by using a dispersant or the like, the liquid material includes nano ink in which very fine ultrafine particles of about several nanometers are dispersed at a high metal content at room temperature. That is, any material having fluidity that can be discharged, applied, ejected, dropped, etc. on the body surface of the piezoelectric element can be used as the liquid material of the present invention. In the following, “liquid material” has the same meaning as this.
Further, examples of means for providing the liquid material include tampo (pat) printing, screen printing, and application by a dispenser, in addition to the inkjet method described later.
The planar shape of the piezoelectric element can be exemplified by a rectangular shape, an annular shape, a circular shape, a truss shape, a trapezoidal shape, and the like.

  The vibrating body according to a second aspect of the present invention includes a conductive reinforcing plate interposed between the piezoelectric element and the piezoelectric element, and the body surface portion includes the reinforcing plate side surface portion, It is preferable that an insulating layer is interposed between the side surfaces of the reinforcing plate.

  According to the present invention, a voltage is applied between the electrode flat portion on which the electrode is formed and the reinforcing plate by using a conductive reinforcing plate and insulation between the side surface portion of the reinforcing plate and the conductive portion. That is, a reinforcing plate can be used as an electrode. Here, even if an insulating layer or the like is formed between the conductive portion and the side surface portion of the reinforcing plate, the wire bonding and overhang are much thinner than a gap of a predetermined dimension is necessary to prevent a short circuit. Can be

  In the vibrator according to the second aspect of the invention, the insulating layer is formed by providing an insulator that is liquid at room temperature on the side surface of the reinforcing plate, and then drying and solidifying the insulator at a temperature higher than room temperature. Is preferred.

According to the present invention, since the insulating layer is also formed by the same means as that of the conductive portion, it is possible to reduce the size, facilitate the manufacture, and not reduce the energy efficiency as compared with the case where an insulating plate is provided. The effect can be made larger.
In addition, regarding the formation of this insulating layer, an ink jet method, which will be described later, can be used. As an insulator that can be used as ink, an epoxy insulating resin can be exemplified.

  In the vibrating body according to the second aspect of the invention, it is preferable that a concave portion recessed in a direction intersecting the stacking direction is formed on the side surface of the reinforcing plate.

  According to the present invention, when the insulating layer is formed, the liquid insulator accumulates in the concave portion, and the liquid material is less likely to sagg at the corner portion formed by the electrode flat surface portion and the piezoelectric element side surface portion. For this reason, when forming a conduction | electrical_connection part on this insulating layer, a liquid substance is stabilized also in a corner | angular part and it becomes easy to form a conduction | electrical_connection part. Thereby, the conduction | electrical_connection quality of a conduction | electrical_connection part can be made more favorable.

Here, as one form of the concave portion, for example, the reinforcing plate side surface portion is arranged to be offset inward from the piezoelectric element side surface portion, and is formed by being surrounded by the reinforcing plate side surface portion and the plane portion of each piezoelectric element. Concave portions and the like are also included.
Further, when the reinforcing plate is formed by removing the metal plate by etching on both the front and back surfaces of the metal plate, such a recess can be formed by proceeding with the etching. In addition, the concave portion can be formed by cutting and polishing a reinforcing plate side surface portion formed by wire cutting or press punching of a metal plate.

  In the vibrating body according to the second aspect of the present invention, it is preferable that a step portion having a substantially L-shaped cross section is formed at a corner portion between the electrode plane portion and the side surface portion of the piezoelectric element.

According to this invention, when the insulating layer is formed, the liquid material accumulates inside the stepped portion, so that the liquid material does not sag at the corners of the vibrating body, and the insulating layer is formed smoothly on the side surface portion of the vibrating body. Easy to do. When the conductive portion is formed over the insulating layer, since the liquid material is easily deposited on the outer peripheral portion of the insulating layer accumulated inside the stepped portion, the conductive portion is easily formed. Thereby, the conduction | electrical_connection quality of a conduction | electrical_connection part can be made better like the structure in which the above-mentioned recessed part was formed.
Such a stepped portion can be formed by so-called step cut or the like.

  In the vibrating body according to the second aspect of the present invention, it is preferable that a corner between the electrode plane portion and the side surface portion of the piezoelectric element is chamfered obliquely with respect to the thickness direction of the piezoelectric element.

  According to the present invention, when the insulating layer is formed, the chamfering causes a sagging to the corner portion of the liquid insulator as compared with a case where the corner portion between the electrode plane portion and the side surface portion of the piezoelectric element is a right angle. Therefore, it is easy to form the insulating layer smoothly. When the conductive portion is formed over the insulating layer, the liquid material is stabilized even at the corner portion, and the conductive portion is easily formed. Thereby, the conduction | electrical_connection quality of a conduction | electrical_connection part can be made better like the structure in which the above-mentioned recessed part and level | step-difference part were formed.

  In the vibrating body according to the second aspect of the present invention, it is preferable that an insulating reinforcing plate interposed between the piezoelectric element and the piezoelectric element is provided, and the body surface portion includes the reinforcing plate side surface portion.

  According to this invention, since the reinforcing plate is insulative, it is not necessary to provide an insulating means such as an insulating layer between the side surface portion of the reinforcing plate and the conducting portion.

  The piezoelectric actuator of the present invention includes the above-described vibrating body, and drives the driven body by transmitting the vibration of the vibrating body to the driven body.

According to this invention, since the above-described vibrating body is provided, the same operations and effects as described above can be enjoyed.
The type of driving the driven body by vibration (ultrasonic motor), regardless of the driving method of the piezoelectric actuator, is, for example, a standing wave driving method in which the position of the vibration node and the antinode is unchanged, the node and antinode A traveling wave driving method in which the position of the transition is appropriately adopted. Further, the polarization direction of the piezoelectric element, the direction of voltage application, and the like can be arbitrarily configured.
As the driven body, a rotor that is rotationally driven, a linear driven body that is linearly driven, or the like can be adopted, and the driving direction of the driven body can be arbitrarily configured.

  The piezoelectric actuator of the present invention is a piezoelectric actuator comprising the vibrating body having a reinforcing plate in the second invention, and driving the driven body by transmitting the vibration of the vibrating body to the driven body, A protrusion projecting toward the driven body is formed on the side surface portion of the reinforcing plate, and the side surface portion and the conducting portion are formed on the side surface portion of the reinforcing plate opposite to the side on which the protrusion is formed. An insulating mold member is provided between the two.

  According to the present invention, it is possible to cause the mold member to function as a projection counter by appropriately forming the mold member. Moreover, when a reinforcement board is electroconductive, insulation with a conduction | electrical_connection part and a reinforcement board side part is achieved by the mold member. In addition, when the recessed part is formed in the reinforcement board side part as mentioned above, a mold member can be favorably hold | maintained in this recessed part.

  An electronic apparatus according to the present invention includes the above-described vibrator or the above-described piezoelectric actuator.

According to the present invention, since the vibration body or the piezoelectric actuator described above is provided, the same operations and effects as described above can be enjoyed.
Here, as the electronic device of the present invention, various electronic devices such as a camera, a printer, a portable information device, a movable toy, and a measuring device are targeted. The above-described piezoelectric element is incorporated as a drive mechanism or an oscillator in these electronic devices.

  The electronic device of the present invention is preferably a timepiece including a timekeeping section and a time information display section for displaying information timed by the timekeeping section.

According to this invention, by replacing a general stepping motor or the like as a driving means in a timepiece and adopting a piezoelectric actuator using the piezoelectric element of the present invention, it is not affected by magnetism and has a high response and a minute response. Feeding is possible, which is advantageous for downsizing and thinning, and offers many advantages such as high torque and large holding torque (the rotor position is maintained even when no power is supplied).
Here, the piezoelectric actuator can be incorporated in a calendar driving mechanism or a driving mechanism for a pointer indicating time. In this case, the time and calendar information can be displayed by driving a gear with a rotor or the like sent by vibration of the piezoelectric element and driving a pointer, a rotating plate, or the like via the gear.

  The method for manufacturing a vibrating body according to the present invention includes an electrode forming step of forming a plurality of electrodes on each of the piezoelectric elements constituting the vibrating body, and a liquid containing conductive particles at room temperature including the side surface of the piezoelectric element. A conductive part that forms a conductive part that electrically connects the electrodes by bringing the conductive particles into contact with each other by drying and solidifying the liquid material at a temperature higher than normal temperature after being provided on the body surface part of the body And a forming step.

  According to the present invention, the conductive portion can be formed as a thin film along the side surface portion of the piezoelectric element by using the liquid material. Therefore, as described above, downsizing, ease of manufacture, and energy efficiency can be achieved. Effects such as improvement can be obtained.

  In the vibrating body manufacturing method according to the aspect of the invention, it is preferable that, in the conduction portion forming step, the conduction portion is formed by ejecting ink as the liquid material onto the body surface portion.

According to the present invention, by using such an ink jet method, a necessary amount of ink is ejected only to a portion where the conductive portion needs to be formed, and the conductive portion can be formed more finely and thinly. It is done. Moreover, since the integrity of the vibrating body and the conductive portion is increased by the thinness, energy efficiency can be improved. Furthermore, the film thickness can be easily controlled by controlling the injection amount (discharge amount), and the film can be formed with different film thicknesses and materials at different locations on the body surface portion of the vibrator.
Note that the ink jet method has an advantage that the amount of material used can be reduced as compared with the case where the conductive portion is formed using photolithography or the like because the ink is ejected only in a necessary portion without excess or deficiency.
In addition, since no mask is used, high-mix low-volume production is possible and equipment costs can be greatly reduced. In addition, there is almost no chemical waste.

  Here, since the ink jet method is a method that does not contact the surface to be ejected, it is possible to easily form a conductive portion at the corner portion between the electrode plane portion and the side surface portion of the piezoelectric element as compared with other printing means. .

  According to the above-described present invention, a piezoelectric element, a piezoelectric actuator, and an electronic device that can be remarkably reduced in size and easy to manufacture with no reduction in energy efficiency can be provided regarding the conduction structure of the piezoelectric element.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As an embodiment of the electronic apparatus, a printer incorporating a piezoelectric actuator and an electronic timepiece (9th embodiment) will be exemplified.

[First Embodiment]
[1. Overall schematic configuration]
FIG. 1 is a schematic diagram of a printer 1 according to the present embodiment. The printer 1 includes a paper tray 2 on which printing paper is set, a discharge unit 3 from which printed paper PP is discharged, and a paper feed roller 5 installed inside the housing 4.
The roller 5 sends the paper PP printed by a print driving unit (not shown) to the discharge unit 3.

[2. Paper feed roller drive mechanism]
The driving mechanism for driving the roller 5 includes a piezoelectric actuator (ultrasonic motor) 20, a rotor 28 that is rotationally driven by the vibration of the piezoelectric actuator 20, and a reduction wheel train 29 that transmits the rotation of the rotor 28 while reducing the rotation. It is prepared for.
The reduction gear train 29 includes a gear 291 that is provided coaxially with the rotor 28 and rotates integrally with the rotor 28, and a gear 292 that meshes with the gear 291 and is fixed to the rotation shaft of the roller 5. ing.
The piezoelectric actuator 20 and the rotor 28 are unitized as a piezoelectric actuator unit 10 as shown in FIG.

[3. Configuration of piezoelectric actuator unit]
The piezoelectric actuator unit 10 includes a rectangular support plate 11 attached to a frame or the like of the housing 4, a piezoelectric actuator 20 attached to each of the support plates 11, and a rotor 28 as a driven body by the piezoelectric actuator 20. It is configured. Thus, the piezoelectric actuator unit 10 is thin because the piezoelectric actuator 20 and the rotor 28 are arranged adjacent to each other in a plane.

At the four corners of the support plate 11, holes 11 </ b> A for attaching to the frame side of the housing 4 and screw pins 11 </ b> B for attaching a cover member (not shown) are formed. The piezoelectric actuator 20 is substantially at the center of the support plate 11. Are fixed by fixing means such as screws 11C. A positioning pin 11D for fixing the piezoelectric actuator 20 is formed in the vicinity of the screw 11C.
In addition, a concave portion 11E that is recessed in the thickness direction of the support plate 11 is formed in a portion of the support plate 11 facing the piezoelectric actuator 20 with a larger planar dimension than the piezoelectric actuator 20, and the piezoelectric actuator 20 has sufficient amplitude. Vibration is possible.

[4. Configuration of piezoelectric actuator]
FIG. 3 is a perspective view of the piezoelectric actuator 20, and FIGS. 4 and 5 are cross-sectional views of the piezoelectric actuator 20.
3 to 5, the piezoelectric actuator 20 includes two rectangular plate-shaped piezoelectric elements 30A and 30B, and a plate-shaped reinforcing plate 21 interposed between the piezoelectric elements 30A and 30B. It has. The piezoelectric element 30A, the reinforcing plate 21, and the piezoelectric element 30B are laminated to each other, and are configured as a vibrating body (piezoelectric element, laminated body) 20A that vibrates with expansion and contraction of the piezoelectric elements 30A and 30B.

  The reinforcing plate 21 is a conductive member such as stainless steel, and is a pair of substantially rectangular main bodies 211 on which the piezoelectric elements 30 </ b> A are stacked and a pair of both sides of the main body 211 that extend to the outside of the main body 211. Arm portions 212 and 213 as extending portions.

At approximately the center of one short side of the main body 211, a protrusion 211A that is in contact with the outer peripheral surface of the rotor 28 (FIG. 2) (in the present embodiment, a cross-sectional arc shape) is formed integrally with the main body 211, and the protrusion 211A Are arranged along the radial direction of the rotor 28 when the piezoelectric actuator 20 is incorporated into the unit 10.
The relative position between the protrusion 211A and the rotor 28 is adjusted so that the protrusion 211A abuts against the outer peripheral surface of the rotor 28 with a predetermined force, and an appropriate frictional force is provided between the protrusion 211A and the rotor 28 side surface. Is generated, the vibration of the vibrating body 20A is efficiently transmitted to the rotor 28. Note that a protrusion substantially the same as the protrusion 211A may be formed as a counter on the other short side of the main body 211.
Further, the main body 211 is slightly shorter than the piezoelectric elements 30A and 30B, and both side surface portions 211C (FIG. 8) on the short side of the main body 211 are located inside the short side surface portions 353 of the piezoelectric elements 30A and 30B. It is arranged offset. Thereby, the recessed part 201 enclosed by the side part 211C of the main body 211 and each plane part of each piezoelectric element 30A, 30B is formed (FIG. 8).

The arm portion 212 has holes 212A and 212C through which the positioning pins 11D (FIG. 2) are inserted, and a hole 212B through which the screw 11C is inserted, and the arm portion 213 has similar holes 213A to 213C. Has been. These arm portions 212 and 213 are fixed to the support plate 11 by screws 11C (FIG. 2), respectively. In addition, the support plate 11 shall be insulated.
One arm portion 212 is electrically connected to a circuit board outside the piezoelectric actuator 20 by conduction means (not shown), and the reference potential in the circuit block of the circuit board is supplied to the arm portion 212.
Since the portions of the arm portions 212 and 213 that are connected to the main body 211 are neck-shaped constricted portions 212D and 213D, dissipation of vibration energy of the vibrating body 20A to the arm portions 212 and 213 is suppressed. The

[5. Configuration of piezoelectric element]
Piezoelectric elements 30A and 30B are composed of lead zirconate titanate (PZT (registered trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, lead zinc niobate, scandium niobate. It is made of a material arbitrarily selected from lead or the like, polarized in the thickness direction, and firmly bonded to the reinforcing plate 21 with an epoxy adhesive or the like. Note that the polarization directions of the piezoelectric elements 30 </ b> A and 30 </ b> B are opposite to each other and are symmetric with respect to the reinforcing plate 21.
Further, both long side surface portions 352 along the longitudinal direction of the piezoelectric elements 30A and 30B are inclined with respect to the thickness direction of the piezoelectric elements 30A and 30B. As a result, the corner between the surface portion (electrode plane portion 351) and the long side surface portion 352 at the end portions in the width direction of the piezoelectric elements 30A and 30B is chamfered, and as shown in FIG. As θ1 is increased, the angle θ2 between the long side surface portion 352 and the surfaces of the arm portions 212 and 213 is also increased.

  In the piezoelectric elements 30A and 30B, assuming that the outer surface that does not overlap the reinforcing plate 21 is the front surface and the surface that overlaps the reinforcing plate 21 is the back surface, at least substantially the entire surface of the piezoelectric elements 30A and 30B has nickel (Ni). Electrodes 31 are formed by plating with metal gold (Au) or the like, sputtering, vapor deposition, or the like. In the present embodiment, an electrode (not shown) substantially the same as the electrode 31 is formed on the entire back surface of the piezoelectric elements 30A and 30B, and the electrode and the reinforcing plate 21 are in contact with each other. , 30B, such an electrode may not be formed and may be directly stacked on the reinforcing plate 21.

Here, since the configuration of the piezoelectric element 30A and the configuration of the piezoelectric element 30B are substantially similar to each other, the configuration common to the piezoelectric elements 30A and 30B may be collectively referred to as the piezoelectric element 30 below.
Further, in the present embodiment, as will be described later, the electrode flat surface portion 351 in which the electrode 31 is formed in the piezoelectric elements 30A and 30B, the short side surface portions (piezoelectric element side surface portions) 353 of these piezoelectric elements 30A and 30B, It is characterized in that a conduction pattern or the like is formed on the body surface portion 35 of the vibrating body 20A including.

The electrode 31 formed on the surface of the piezoelectric element 30 is divided by a groove 32 formed by etching or the like, and five electrode patterns 311 to 315 that are insulated from each other are formed.
The division pattern of these electrode patterns 311 to 315 is generally such that the rectangular electrode 31 is divided into three equal parts in the width direction by the grooves 32 along the longitudinal direction of the piezoelectric element 30 and divided into three equal parts. The electrode is further divided into two at substantially the center in the longitudinal direction. These electrode patterns 311 to 315 are point-symmetric with respect to the center line along the longitudinal direction of the piezoelectric element 30 and with respect to the plane center. They are arranged symmetrically.

  Specifically, these electrode patterns 311 to 315 have a reduced width dimension at the center in the longitudinal direction of the piezoelectric element 30, and the electrode patterns 311 and 312 respectively disposed on both sides of the piezoelectric element 30 in the longitudinal direction are Alternatively, the electrode pattern 314 and the electrode pattern 315 protrude alternately beyond the longitudinal center of the piezoelectric element 30. As a result, all of the electrode patterns 311 to 315 are arranged with a width substantially equal to the longitudinal central portion of the piezoelectric element 30, and any of these electrode patterns 311 to 315 can be electrically connected to the longitudinal central portion of the piezoelectric element 30. it can.

[5-1. About conduction structure (wiring)]
FIG. 6 is a plan view showing a state in which the piezoelectric actuator 20 is wired.
In the present embodiment, by appropriately using the electrode patterns 311 to 315, the rotor 28 (FIG. 2) is driven in the forward direction R + and the reverse direction R-, and the paper feed roller 5 (FIG. 1) is moved in the forward direction and in the reverse direction. Can also be driven.

Specifically, a voltage is applied to the central electrode pattern 313 extending substantially in the longitudinal direction at the approximate center of the piezoelectric element 30 when the rotor 28 rotates in the forward direction R + and in the reverse direction R−. In addition, a voltage is applied to the symmetrical electrode patterns (electrode pairs) 311 and 315 arranged on one diagonal line only when the rotor 28 rotates in the positive direction R +, and the symmetrical electrode pattern arranged on the other diagonal line. A voltage is applied to the (electrode pairs) 312 and 314 only when the rotor 28 rotates in the positive direction R−.
The electrode pattern (symmetric electrode patterns 311 and 315 or symmetrical electrode patterns 312 and 314) to which no voltage is applied according to the forward and reverse rotations of the rotor 28 is used as a detection electrode that extracts the vibration state of the piezoelectric actuator 20 as a voltage signal. Is done. The vibration detection signal is a differential signal that is a potential difference between the symmetrical electrode patterns 311 and 315 with respect to the reference signal or a potential difference between the symmetrical electrode patterns 312 and 314 with respect to the reference signal. Detected.

The central electrode pattern 313 is provided around the hole 212B through the constricted portion 212D of one arm portion 212 by an L-shaped conductive pattern (conductive portion) 411 formed by drying and solidifying the liquid material. Conductive to the foil-like pad 452 is conducted from the pad 452 to a drive control device mounted on a circuit board (not shown) by an arbitrary conducting means. The central electrode pattern 313 is continuously formed over the electrode plane portion 351, the long side surface portion 352, and the surface portion of the arm portion 212 of the piezoelectric element 30.
Here, an insulating layer 511 using a liquid insulator is formed in a region where the substantially rectangular portion at the substantially central portion in the longitudinal direction of the piezoelectric element 30 and the surface of the arm portion 212 are combined. The insulating layer 511 prevents the central electrode pattern 313 from being electrically connected to the electrode patterns 314 and 315 on the path of the conductive pattern 411.
Such an insulating layer 511 is necessary when the intermediate portion 411B between the contacts 411A at both ends of the conductive pattern 411 overlaps with a portion having a different potential. That is, when viewed from the center electrode pattern 313, the symmetrical electrode patterns 312 and 314 become different potential portions when the rotor 28 rotates forward, and the symmetrical electrode patterns 311 and 315 become different potential portions when the rotor 28 rotates backward. It is necessary to insulate 411 and electrode patterns 311 to 315 from each other. The conductive pattern described below also has an intermediate portion that overlaps with the different potential portion between the contact points, and therefore the insulating layer is necessary, and therefore, the description regarding the contact points and the intermediate portion is simplified or omitted hereinafter. To do.

The insulating layer 511 is continuously formed along the surfaces of the electrode plane portion 351, the long side surface portion 352, and the arm portion 212 of the piezoelectric element 30, and three pieces are provided on the arm portion 212 by the insulating layer 511. Pads 451-453 are insulated from each other.
In addition, since it is electrically connected from the one side of the piezoelectric actuator 20 to the exterior of the piezoelectric actuator 20 via the pads 451-453 provided in one arm part 212, wiring work becomes easy. However, the present invention is not limited thereto, and any one of the electrode patterns 311 to 315 may be conducted to the outside of the piezoelectric actuator 20 via the other arm portion 213.

  The conductive patterns 411 to 414 and the like formed on the piezoelectric element 30 and the insulating layer 511 and the like are all dried / solidified after discharging a liquid / liquid insulator toward the piezoelectric element 30 (specifically, The ink jet method (ink jet method), which will be described later, is formed.

The symmetrical electrode patterns 311 and 315 are the same in-plane mutual conductive electrodes that are electrically connected to each other, and are electrically connected to each other by the substantially L-shaped conductive pattern (in-plane conductive portion) 412 to have the same potential. That is, although the symmetrical electrode patterns 311 and 315 are located at positions separated from each other, the insulating layer 511 is formed so that the symmetrical electrode patterns 311 and 315 are electrically connected to each other across the other electrode patterns 313 and 314. It becomes possible.
The conduction pattern 412 passes through the constricted portion 212D of the arm portion 212, is conducted to the pad 453 provided around the hole 212C, and is conducted to the drive control device. Note that the insulating layer 511 is not formed in a portion where the conductive pattern 412 of the electrode pattern 315 passes.

The symmetrical electrode patterns 312 and 314 are also the same in-plane mutual conductive electrodes, and are electrically connected to each other by a U-shaped conductive pattern (same-plane conductive portion) 413 across the central electrode pattern 313 at the portion where the insulating layer 511 is formed. As a result, the electric potential is made the same, and the electric potential is conducted to the drive control device through the L-shaped conductive pattern 414 (the same in-plane conductive portion) provided on one electrode pattern 314 and the pad 451 of the arm portion 212.
In addition, by adjusting the film thickness and length of the conductive patterns 413 and 414 and the film thickness and length of the conductive pattern 412 described above, the electric resistance by the sum of the conductive patterns 413 and 414 and the conductive pattern 412 are adjusted. The electrical resistance is adjusted to be substantially the same and is equivalent wiring.

  The conductive patterns 411 to 414 and the insulating layer 511 described above are formed only on the piezoelectric element 30A, and the electrode patterns 311, the electrode patterns 312, the electrode patterns 313, and the electrode patterns 314 in each of the piezoelectric elements 30A and 30B. The electrode patterns 315 (each mutual conductive electrode) are electrically connected to each other by the conductive patterns 415 to 419 passing through the short side surface portions 353 of the piezoelectric elements 30A and 30B to have the same potential.

FIG. 7 shows the side surface portion 20B on the short side of the vibrating body 20A. The conductive patterns 416, 417, and 419 include an electrode plane portion 351 of the piezoelectric element 30A, a short side surface portion 353 of the piezoelectric element 30A, a side surface portion (reinforcement plate side surface portion) 211C of the reinforcing plate 21, and a short side surface of the piezoelectric element 30B. It is formed along the body surface portion 35 including the portion 353 and the electrode plane portion 351 of the piezoelectric element 30B.
Here, an insulating layer 512 obtained by drying and solidifying a liquid insulator is interposed between the conductive patterns 416, 417, and 419 and the side surface portion 211C of the reinforcing plate 21. The insulating layer 512 and the conductive pattern 417 are shown in the sectional view of FIG. The insulating layers 512 are formed on both short sides of the vibrating body 20A, and the insulating layers 512 are interposed between the conductive patterns 415 and 418 and the side surface portion 211C of the reinforcing plate 21, respectively.

Such an insulating layer 512 covers the side surface portion 211C of the reinforcing plate 21 by discharging a liquid material into the concave portion 201 formed in the side surface portion 211C of the reinforcing plate 21 (the back surfaces of the piezoelectric elements 30A and 30B). It is formed so as to cover an electrode (not shown) formed on the side. The short side surface portions 353 of the piezoelectric elements 30A and 30B may not be covered with these insulating layers 512, but the bases of the piezoelectric elements 30A and 30B, which are generally porous structures (porous), are generally insulating layers. Since the short side surface portion 353 is smoothed by being covered with 512, the conductive patterns 415 to 419 can be easily formed over the insulating layer 512.
These insulating layers 512 insulate the electrode patterns formed on the electrode plane portions 351 of the piezoelectric elements 30 </ b> A and 30 </ b> B from the reinforcing plate 21.

  7 and 8, the electrode patterns 311 to 315, the conductive patterns 411 to 419, the insulating layers 511 and 512, etc. are shown to be thicker than the actual thickness. The electrode patterns 311 to 315 are about several μm to several tens of μm, and the conductive patterns 415 to 417 are about several nm to several μm. The film thicknesses of the insulating layers 511 and 512 are appropriately set according to the voltage applied to the piezoelectric elements 30A and 30B, the vibration voltage output from the symmetrical electrode pattern 311 and the like.

  As described above, the piezoelectric elements 30A and 30B are connected in parallel with the reinforcing plate 21 as a common electrode, and between the electrode patterns 311 to 315 formed on the surface of the piezoelectric element 30A and the reinforcing plate 21, and the piezoelectric elements. An AC voltage is applied between each of the electrode patterns 311 to 315 formed on the surface of the element 30 </ b> B and the reinforcing plate 21 by a drive control device (not shown). Then, the piezoelectric elements 30A and 30B are simultaneously expanded and contracted by the piezoelectric lateral effect that is displaced in the direction orthogonal to the polarization direction and the electric field direction. That is, when the piezoelectric element 30A expands, the piezoelectric element 30B also expands, and when the piezoelectric element 30A contracts, the piezoelectric element 30B also contracts.

[6. Configuration of Drive Control Device]
The drive control device for the piezoelectric actuator 20 mounted on a circuit board (not shown) will be briefly described. The drive control device includes a voltage application unit that applies an AC voltage to the piezoelectric elements 30A and 30B, and vibration of the vibrating body 20A. A vibration detecting unit for detecting a state. Further, a selector is provided for energizing the symmetric electrode patterns 311 and 315 and the symmetric electrode patterns 312 and 314 to either the voltage application device or the vibration detection device according to the rotation direction of the rotor 28. The waveform of the voltage applied by the voltage application unit is not particularly limited, and for example, a sine wave, a rectangular wave, a trapezoidal wave, or the like can be employed.

In the present embodiment, the phase of the drive signal oscillated by the voltage application unit is a single phase, and the drive signals having the same phase are supplied to the electrode patterns 311 to 315 and the reinforcing plate 21.
Here, the vibration body 20A of the piezoelectric actuator 20 has the length ratio and thickness of the piezoelectric elements 30A and 30B such that the protrusion 211A draws a good vibration locus and the rotor 28 can be driven with high efficiency. The frequency of the drive voltage is set for the vibrator 20A designed as described above. This drive frequency is set so that the longitudinal vibration resonance point and the bending resonance point when the vibrating body 20A vibrates are close to each other.

[7. Operation of piezoelectric actuator]
The operation of the piezoelectric actuator 20 described above will be described with reference to FIG.
When the central electrode pattern 313 and the symmetrical electrode patterns 311 and 315 are fed from the voltage application unit of the drive control device, the piezoelectric elements 30A and 30B expand and contract in the longitudinal direction in the region of the electrode patterns 311 313 and 315, and vibrate. The body 20A excites longitudinal primary vibration along the longitudinal direction. At this time, due to the arrangement of the symmetric electrode patterns 311, 315, a moment is generated clockwise in FIG. 6 around the plane center of the vibrating body 20A, and the vibrating body 20A induces a bending secondary vibration that is bent and displaced in the width direction. . The piezoelectric actuator 20 is driven in a mixed mode of these longitudinal vibration and bending vibration. Due to the phase difference between the longitudinal vibration and the bending vibration, the protrusion 211A draws an elliptical orbit (+). The rotor 28 (FIG. 2) is finely fed in the positive direction (R +) in a direction tangential to the elliptical orbit (+), and the protrusion 211A continues to move elliptically at a predetermined drive frequency, thereby feeding the paper through the rotation of the rotor 28. The roller 5 is rotationally driven in the forward direction.
At this time, the symmetrical electrode patterns 312 and 314 are energized to the vibration detection unit of the drive control device, and the drive control device variably controls the frequency of the drive voltage generated by the voltage application unit based on the detected vibration state. The

On the other hand, when the paper feed roller 5 is rotated in the reverse direction, the central electrode pattern 313 and the symmetrical electrode patterns 312 and 314 are fed from the voltage application unit of the drive control device, and the symmetrical electrode patterns 311 and 315 are driven and controlled. The vibration detection unit of the apparatus is energized.
Here, due to the arrangement of the symmetrical electrode patterns 312, 314, a moment is generated in the vibrating body 20A in the counterclockwise direction in FIG. 6 opposite to the above, and the protrusion 211A is opposite to the above-described elliptical orbit (+). Draw a surrounding elliptical orbit (-). As a result, the rotor 28 is rotationally driven in the reverse direction R-, and the paper feed roller 5 is rotationally driven in the reverse direction.

FIG. 9 is a schematic diagram illustrating bending vibration of the vibrating body 20A. The node A of the vibrating body 20A is at the center in the vibration plane of the vibrating body 20A, and B is the antinode of the vibrating body 20A.
Here, as shown in FIG. 3 and the like, each of the electrode patterns 311 to 315 and the constricted portions 212D and 213D of the arm portions 212 and 213 are all arranged at the approximate center in the longitudinal direction of the piezoelectric element 30. 411 to 414 are also formed in accordance with the positions of these electrode patterns 311 to 315 and the constricted portions 212D and 213D, respectively. That is, the conductive patterns 411 to 414 are formed in the vicinity of the node A of the vibrating body 20A.

[8. Configuration of inkjet means]
Next, an ink jet unit used when forming the conductive patterns 411 to 419 and the insulating layers 511 and 512 will be described.
FIG. 10 is an enlarged view of an inkjet head 110 as an inkjet means. The inkjet head 110 includes an ink chamber 111 that accumulates ink, a plurality of nozzles 112 that eject ink from the ink chamber 111 to the vibrating body 20A, and ink. A plurality of pressure generation chambers 113 that communicate with the chamber 111 and the nozzle 112 and whose flow paths can contract (the same number as the nozzles 112), and a piezoelectric vibrator 114 that compresses the pressure generation chamber 113 and contracts the flow path. I have.

The nozzles 112 are constituted by nozzle holes formed in the nozzle plate 1121 by press working or the like, and are arranged at a predetermined interval.
FIG. 11 shows an enlarged cross-sectional view of the nozzle 112. In FIG. 11, a plating layer 1122 by plating of nickel or the like is provided on the outer surface 1121A of the nozzle plate 1121, and this plating layer 1122 is formed with a predetermined distance around the nozzle 112 opening. Thus, a step 1122A is formed around the nozzle 112.
Further, a plating layer 1123 is further formed on the outer surface of the plating layer 1122 by composite plating. The plating layer 1123 is also formed on the inner periphery of the nozzle 112.
By this plating layer 1123, the outer surface of the nozzle plate 1121 is subjected to ink repellent treatment. Further, a hydrophilic treatment is applied to a portion of the inner surface of the nozzle 112 where the plating layer 1123 is not formed. By these ink repellent treatment and hydrophilic treatment, the ink 120 (FIG. 12) ejected from the nozzle 112 is well prevented from adhering to the nozzle plate 1121, and a substantially spherical droplet is stably ejected ( (Discharge amount). Further, the ink 120 is ejected straight along the direction in which the nozzle 112 is formed by this ink repellent treatment.

Outside the pressure generation chamber 113, piezoelectric vibrators 114 that contract the pressure generation chamber 113 are provided according to the number of pressure generation chambers 113. These piezoelectric vibrators 114 excite longitudinal vibration that expands and contracts in the longitudinal direction when a voltage is applied. The tip of the piezoelectric vibrator 114 is fixed to the outer wall of the pressure generating chamber 113.
Thin portions 113A are formed on both sides of the piezoelectric vibrator 114 on the outer wall of the pressure generating chamber 113, respectively. Due to the thin portion 113A, the outer wall is easily deformed by the vibration of the piezoelectric vibrator 114.
In such an ink jet head 110, when a predetermined voltage is applied to the piezoelectric vibrator 114 and vibrated, the piezoelectric vibrator 114 presses the outer wall of the pressure generating chamber 113 to contract the pressure generating chamber 113. As a result, the ink in the pressure generation chamber 113 is pushed out and ejected as fine droplets from the nozzle 112.

12A and 12B are diagrams showing the ink 120 ejected from the nozzle 112. FIG. As shown in FIG. 12, the ink 120 ejected from the nozzle 112 has a substantially spherical shape and is ejected straight along the direction in which the nozzle 112 is drilled. When the piezoelectric vibrator 114 is returned to its original position and then slightly contracted after the ink 120 droplets are ejected, the pressure generating chamber 113 expands and protrudes into a hemisphere due to surface tension at the nozzle 112 opening. Ink 120 is drawn into nozzle 112. As a result, problems such as the ink 120 spilling from the nozzle 112 are reliably eliminated. Further, by controlling the displacement of the piezoelectric vibrator 114 to positively control the behavior of the ink 120 in the nozzle 112 opening, the droplet discharge amount is stabilized.
In addition, by adjusting the displacement amount and displacement speed of the piezoelectric vibrator 114, the ejection amount of the ink 120, the size of the droplets, and the ejection speed can be adjusted.

Such an inkjet head 110 has an in-plane direction (X direction, Y direction) and an out-of-plane direction (Z direction) of the surface on which the ink 120 is ejected in the piezoelectric elements 30A and 30B and the reinforcing plate 21 by a moving mechanism (not shown). Each can be moved. The ink jet head 110 directly draws the conductive patterns 411 to 419 and the insulating layers 511 and 512 on the piezoelectric elements 30A and 30B with a determined film thickness and length while adjusting the discharge amount of the ink 120 and the like.
Here, the adjustment of the ink discharge amount is performed by adjusting the film thickness and length determined for each of the conductive patterns 411 to 419, the film thickness and the area of the range required for each of the insulating layers 511 and 512, and the solvent in the ink. This is performed based on the evaporation speed of the ink jet head 110, the distance from the inkjet head 110 to the ink ejection surface of the vibrating body 20A, and the like.
Alternatively, the discharge amount of the ink discharged from the ink jet head 110 may be monitored and adjusted to discharge a predetermined discharge amount set in advance. That is, since the discharge amount discharged from the ink jet head 110 at one time is set in advance by the displacement amount of the piezoelectric vibrator 114, the number of liquid discharges from the nozzle 112 is set in advance. A fixed amount can be discharged. The predetermined discharge amount is preferably set in consideration of the amount of solvent added during preparation.

[9. Method for manufacturing vibrator]
Next, a manufacturing method of the vibrating body 20A will be described with reference to FIGS. As shown in the flowchart of FIG. 13, the manufacturing process of the vibrating body 20 </ b> A includes an electrode forming process S <b> 1, an individualizing process S <b> 2, a stacking process S <b> 3, an insulating layer forming process S <b> 4, and a conduction part forming process S <b> 5. Have.
[9-1. Electrode formation process]
14A and 14B show a substrate 300 on which a large number of piezoelectric elements 30 are formed. In the present embodiment, a base material 300 formed in a rectangular plate shape as shown in FIG. Then, electrodes 31 are formed on both the front and back surfaces of the substrate 300 by plating, sputtering, vapor deposition, or the like (FIG. 14A), and grooves 32 are formed on the surface of the electrodes 31 by etching (FIG. 14B). ).
FIG. 15 is an enlarged view of FIG. The piezoelectric elements 30 to be individually separated later are arranged so as to alternate between the front and back in the direction along the short direction. On the other hand, in the direction along the longitudinal direction, the front and back directions of each piezoelectric element 30 are aligned, and a groove 32 extending in the longitudinal direction is continuously formed in each piezoelectric element 30.

[9-2. Individualization process]
Next, the substrate 300 is diced along the alternate long and short dash line in FIG. 15, and is divided into individual piezoelectric elements 30 (individualization step S2). Here, as shown in the side view of the substrate 300 in FIG. 16, the long side of each piezoelectric element 30 is diced diagonally along the dashed line in FIG. An inclined long side surface portion 352 is formed.

[9-3. Lamination process]
In the next lamination step S3, the piezoelectric elements 30A and 30B are joined to a reinforcing plate 21 (FIG. 3) separately formed by press punching of a stainless steel plate or the like, and a vibrating body 20A as a laminated body is manufactured. In this case, as shown in the schematic view of FIG. 17, an epoxy-based conductive adhesive is applied to the bonding surface in the order of the piezoelectric element 30B, the reinforcing plate 21, and the piezoelectric element 30A on the support member 100 having the positioning pins 101 to 103. Application and lamination are performed, and pressure is applied by the pressurizing means 105 along the lamination direction. Note that a sheet 106 made of Teflon (registered trademark) or the like is preferably interposed between the pressurizing means 105 and the piezoelectric element 30A. By this pressurization, the piezoelectric element 30A, the reinforcing plate 21, and the piezoelectric element 30 are accurately bonded in parallel to each other and firmly bonded to each other.
The support member 100 is provided with one pin 101 on the short side of the vibrating body 20A and two pins 102 and 103 on both sides of the arm portion 212 on the long side of the vibrating body 20A. Further, when the adhesive is cured, it can be quickly cured by using hot air or the like.

[9-4. Insulating layer formation process]
In the next insulating layer forming step S4, the above-described inkjet head 110 (FIG. 10) is used. The ink used in the insulating layer forming step S4 is prepared as an insulator that is liquid at room temperature.
A resin material such as an epoxy-based insulating resin can be employed for the liquid insulator.

FIG. 18 shows the insulating layers 511 and 512 formed by the insulating layer forming step S4.
In the insulating layer forming step S4, the surface of the electrode plane portion 351 and the arm portion 212 of the piezoelectric element 30 on which the insulating layers 511 and 512 are formed while moving the inkjet head 110 using the liquid insulator as described above as ink. The ink is ejected onto the side portion 20B of the vibration portion 20A. Here, the nozzle 112 that ejects ink is selected by the control means inside the ink jet head 110, and the ink is ejected in an amount that is not excessive or deficient only at the location where the insulating layers 511 and 512 need to be formed.
The angles θ1 and θ2 (FIG. 5) are made obtuse by the inclination of the long side surface portion 352, and the step between the piezoelectric element 30 and the reinforcing plate 21 arranged in parallel to each other is relaxed. The insulating layer 511 can be easily formed from the 30 electrode flat surface portions 351 to the surface of the arm portion 212 via the long side surface portion 352.

  Further, when the insulating layer 512 is formed by ejecting ink to the side surface portion 20B on the short side of the vibrating body 20A, as shown in FIG. 8, since the ink accumulates in the concave portion 201, the ink enters the corner portion 35C. It ’s hard to sag. For this reason, it is easy to form the insulating layer 512 smoothly on the side surface portion 20B of the vibrating body 20A. The posture of the vibrating body 20A when forming the insulating layer 512 may be a state in which the side surface portion 20B stands up depending on the ink curing speed or the like, or a state in which the electrode flat surface portion 351 is the upper surface. It is good.

  After the ink is ejected, the insulating layers 511 and 512 are formed by drying and solidifying the liquid insulator at a temperature higher than normal temperature using hot air or the like.

[9-5. Conducting part forming step]
Next, conductive patterns 411 to 419 are formed over the insulating layers 511 and 512. Also in this conducting portion forming step S5, the above-described inkjet head 110 is used, and a liquid material containing conductive particles is used as ink at room temperature. In addition, it is better in terms of production efficiency to prepare the ink jet head 110 for each of the insulating layer forming step S4 and the conduction portion forming step S5.

As the conductive fine particles contained in the ink used in this step S5, in addition to metal fine particles containing any of gold, silver, copper, palladium, nickel, conductive polymer and superconductor fine particles can be exemplified, A liquid material in which these fine particles are dispersed in a solvent can be used. In order to disperse the fine particles, the surface of the fine particles can be coated with an organic substance. An organic binder or the like can also be used as a bonding agent to the ink ejection surface.
In addition, from the viewpoint of easy dispersion in a solvent and application to an ink jet method, the particle diameter of the fine particles is preferably about 1 nm or more and about 0.1 μm or less.

Here, by using a gas evaporation method or the like and a dispersant, very fine ultrafine particles of about several nanometers can be obtained. Since such ultrafine particles are covered with the dispersant, Even if the metal content is high, it does not aggregate and behaves as a liquid. According to the liquid material (called nano ink) containing such ultrafine particles, a sufficient number of ultrafine particles are fused and fusion-bonded in the thickness, width and length directions of the conductive patterns 411 to 419, so that the conductivity is improved. Can be good.
For this reason, in this embodiment, a liquid material in which such ultrafine particles are dispersed is used as ink. This liquid is prepared so as to contain a trapping substance for trapping the dispersant and an organic binder (resin).

In FIG. 19, the conduction | electrical_connection patterns 411-419 formed by conduction | electrical_connection part formation process S5 are shown.
Also in this step S5, as in the insulating layer forming step S4 described above, the electrode plane portion 351, the long side surface portion 352, and the arm portion 212 on which the conductive patterns 411 to 419 are formed are moved while moving the inkjet head 110. The ink in which the ultrafine particles are prepared in a dispersed state as described above is ejected onto the surface portion and the side surface portion 20B. Here, the ink is ejected while the positions, film thicknesses, lengths, and the like of the respective conductive patterns 411 to 419 are controlled only by the control means inside the ink jet head 110 where the conductive patterns 411 to 419 need to be formed. The

Here, since the insulating layer 512 is formed smoothly on the side surface portion 20B on the short side of the vibrating body 20A, when the conductive patterns 415 to 419 are formed over the insulating layer 512, as shown in FIG. Also, the ink is stable at the corner portion 35C between the electrode plane portion 351 and the short side surface portion 353, and the conductive patterns 415 to 419 are easily formed.
Further, regarding the conductive patterns 411 to 414, the long side surface portion 352 is inclined and the angles θ1 and θ2 (FIG. 5) are large, so this length from the electrode flat surface portion 351 of the piezoelectric element 30 to the arm portion 212 is long. The conductive patterns 411 to 414 can be easily formed via the side surface portion 352.

After the ink is ejected, the liquid is dried and solidified at a temperature higher than normal temperature using hot air or the like. At this time, for example, the dispersant trapping material is activated at a relatively low temperature of about 200 ° C., the dispersant is chemically removed, and the organic binder is cured and contracted, so that the ultrafine particles are fused and fusion bonded. .
Here, since the particle diameter of the nano ink used in this embodiment is on the order of nm, the metal surface is melted at a relatively low temperature due to an increase in the surface energy of the ink, and a metal bond is generated. For example, the melting point of macroscopic Ag is 912 ° C. When the particle diameter is on the order of nm, it is possible to cause melting of the metal even at 150 ° C. This is the most important feature and advantage of nanotechnology. Since the bonding temperature is low, the thermal shock to the piezoelectric element 30 can be reduced.

Conductive patterns 411 to 419 are formed by bringing the conductive particles into contact with each other by drying and solidifying as described above, and the vibrator 20A is completed.
Then, the vibrating body 20A is assembled to the support plate 11 (FIG. 2), the pads 451 to 453 of the arm portion 212 are connected to the drive control device by an arbitrary conduction means, and the arm portion 212 is connected to the drive portion of the printer 1. By conducting to the reference potential circuit block, the assembly of the piezoelectric actuator 20 is completed.

[10. Effects of this embodiment]
According to this embodiment, the following effects can be obtained.
(1) Concerning the wiring of the piezoelectric element 30 of the piezoelectric actuator 20, the conductive patterns 411 to 419 and the insulating layers 511 and 512 are formed using the liquid ink 120, whereby the conductive patterns 411 to 419 and the insulating layers 511 and 512 are formed. Can be formed as a thin film along the body surface portion 35 of the piezoelectric element 30, and the conductive patterns 411 to 419 and the insulating layers 511 and 512 are integrated with the piezoelectric element 30 and the reinforcing plate 21. For this reason, size reduction can be promoted remarkably, without the thickness of the piezoelectric actuator 20 becoming bulky like conducting means, such as a wire and an overhang part. Further, by using the ink 120, fine patterning such as the conductive patterns 411 to 419 is possible, and fine wiring is possible. Therefore, further downsizing and thinning can be further promoted.

Further, in the method using the liquid ink 120 as described above, there is a method in which the positions of the conductive patterns 411 to 419 are controlled by the inkjet head 110 and the discharged ink 120 is dried and solidified by the body surface portion 35 of the piezoelectric element 30. Therefore, the positions of the conductive patterns 411 to 419 are not fixed, and the conductive patterns 411 to 419 are precisely patterned. Furthermore, the assembly of the electrode patterns 311 to 315 to the outside of the piezoelectric element 30 is not required, so that the manufacturing becomes extremely easy. Furthermore, since the conductive patterns 411 to 419 are directly formed on the piezoelectric element 30 and the reinforcing plate 21 as described above, a lead substrate is unnecessary and a structure for holding the substrate is also unnecessary. It becomes. In addition, the substrate cost can be reduced and the cost can be reduced.
And there is no possibility that reliability will fall due to wiring and assembly.

  In addition, since the conductive patterns 411 to 419 and the insulating layers 511 and 512 are integrated into the piezoelectric element 30 and the reinforcing plate 21 as a thin film, the efficiency of mutual conversion between the electrical energy and the mechanical energy of the piezoelectric element 30 is good. Efficiency does not decrease. That is, when the vibrating body 20A vibrates, the conduction patterns 411 to 419 and the insulating layers 511 and 512 are displaced together with the piezoelectric element 30, so that the vibration is not hindered by the conduction patterns 411 to 419, and the driving efficiency can be improved. .

(2) Since the ink-jet method is employed as a method for adhering the ink 120 and drying and solidifying it, it is possible to easily eject the ink 120 to a necessary amount only at a necessary portion, and the conductive patterns 411 to 419 and the insulating pattern are insulated. The layers 511 and 512 can be more uniformly and thinly formed. This contributes to a further reduction in thickness, and due to the thinness, the integrity of the conductive patterns 411 to 419 and the insulating layers 511 and 512, the piezoelectric element 30, and the reinforcing plate 21 is increased, so that energy efficiency can be improved.

(3) The ink-jet head 110 is configured to eject the ink 120 by the vibration of the piezoelectric vibrator 114 and enables a small amount of ink 120 to be ejected, so that the conductive patterns 411 to 419 and the like can be patterned more precisely. Thereby, the dispersion | variation in the vibration characteristic of 20 A of vibrating bodies can be suppressed.
Further, since the ink jet head 110 ejects the ink 120 by compressing the liquid flow path by the vibration of the piezoelectric vibrator 114, for example, compared with a method in which ink droplets are ejected by heating the ink, Performance degradation is reduced.

(4) Since the electrode patterns 311 to 315 formed on the two piezoelectric elements 30A and 30B are electrically connected to each other via the side surface portion 20B of the vibrating body 20A, the front side of the reinforcing plate 21, that is, one piezoelectric element 30A. It is sufficient to perform wiring from the side, and the mounting direction can be aligned in the same direction. Thereby, even after the vibration body 20A is incorporated in the support plate 11, the conduction work between the pads 451 to 453 and the external circuit board can be easily performed. In addition, since the conductive patterns 411 to 414, the pads 451 to 453, the insulating layer 511, and the like need only be provided on the one piezoelectric element 30A side, the thickness of the entire vibrating body 20A can be further reduced.

(5) Since the concave portion 201 is formed in the side surface portion 211C on the short side of the reinforcing plate 21, ink at the time of forming the insulating layer 512 is accumulated in the concave portion 201, and it is difficult for the ink to be dripped into the corner portion 35C. . For this reason, when the conductive patterns 415 to 419 are formed over the insulating layer 512, the ink is stable at the corner portion 35C, and the conductive patterns 415 to 419 are easily formed. Thereby, the conduction quality of the conduction patterns 415 to 419 can be improved.
In addition, since the insulating layer 512 is formed smoothly on the side surface portion 20B of the vibrating body 20A, the adhesiveness of the insulating layer 512 and the conductive patterns 415 to 419 to the electrode flat surface portion 351 and the side surface portion 20B increases. The integrity of the insulating layer 512 and the conductive patterns 415 to 419 to the vibrating body 20A is further improved.

(6) Since the conductive patterns 411 to 414 and the insulating layer 511 are formed in the vicinity of the vibration node A of the vibrating body 20A, the conductive patterns 411 to 414 and the insulating layer 511 greatly affect the vibration of the vibrating body 20A. Can be small. For this reason, the vibration of the vibrating body 20A is not attenuated, and energy efficiency can be improved. Moreover, since wiring is performed in the vicinity of the node A in this way, disconnection during disturbance can be prevented.

(7) The nano ink used for the conductive patterns 411 to 419 has a characteristic that the connection resistance is lower than that of the conductive paste or the like due to the bonding mechanism, and this characteristic enables inkjet, dispenser, screen printing, etc. It can be used in any application method. Here, in particular, the ink jet has characteristics that are not found in other coating methods in which material efficiency is high and fine coating can be performed at an extremely fine level. According to inkjet, for example, the minimum width of patterns can be about 10 μm, and the minimum distance between patterns (the distance at which adjacent patterns are not coupled to each other) can be about 10 μm. For this reason, the use of nano ink becomes more effective by this ink jet method, and the synergistic effect of the ink jet method and the use of nano ink can contribute to further fine wiring.

  Here, a commercially available nano ink and a commercially available conductive paste are compared for each item in the following table. In the table, “IJ” means inkjet. In addition, the pattern width when fine wiring is performed in the case of using nano ink and IJ printing can be about 10 μm, for example, whereas in the case of other printing, it is about 100 μm.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. The present embodiment is configured in substantially the same manner as the first embodiment, but the ink at the corners of the vibrating body is stabilized by means different from the first embodiment.
In the following description, the same reference numerals are given to the same configurations as those in the embodiment described above, and the description is omitted or simplified.

  FIG. 20 is a side sectional view of the piezoelectric actuator 22 in the present embodiment, and corresponds to FIG. 8 of the first embodiment. The vibrating body 22A of the piezoelectric actuator 22 in the present embodiment is configured as a substantially rectangular laminated body, similar to the vibrating body 20A of the first embodiment shown in FIG. 3 and the like, but as shown in FIG. The position of the side surface portion 261 on the short side of the reinforcing plate 26 in the vibrating body 22A is aligned with the position of the short side surface portion 353 of the piezoelectric elements 33A and 33B. Instead, a step portion 331 having a substantially L-shaped cross section is formed at the corner portion 35C on the short side of the piezoelectric elements 33A and 33B.

  In the present embodiment, the step portion 331 is formed by a so-called step cut at a corner portion 35C between the electrode flat surface portion 351 and the short side surface portion 353. In the present embodiment, the stepped portion 331 is formed over the entire short side of the piezoelectric elements 33A and 33B.

  Such a vibrating body 22A is manufactured in substantially the same manner as steps S1 to S5 (FIG. 13) described in the first embodiment. Here, when the insulating layer 512 is formed in the insulating layer forming step S4, since the ink is accumulated inside each stepped portion 331, the ink is unlikely to rise at the corner portion 35C, and the insulating layer 511 is the side surface portion 22B of the vibrating body 22A. It is easy to form smoothly. When the conductive patterns 415 to 419 (FIG. 6) are formed over the insulating layer 512, the conductive patterns 415 to 419 are formed because the ink easily deposits on the outer peripheral portion of the insulating layer 512 accumulated inside the stepped portion 331. It becomes easy to do.

According to this embodiment, in addition to the above-described effects, the following effects can be obtained.
(8) When the insulating layer 512 is formed by forming the step portion 331 at the corner portion 35C of each of the piezoelectric elements 33A and 33B, ink is accumulated in the step portion 331, and the insulating layer 512 can be formed smoothly. Thereby, when forming the conduction patterns 415 to 419, the ink in the corner portion 35C is stabilized, and the conduction quality of these conduction patterns 415 to 419 can be improved.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. The present embodiment is configured in substantially the same manner as each of the above embodiments, but the ink at the corners of the vibrating body is stabilized by means different from the above embodiments.
FIG. 21 is a side sectional view of the piezoelectric actuator 23 in the present embodiment.
The vibrating body 23A in the piezoelectric actuator 23 includes piezoelectric elements 34A and 34B having a substantially rectangular shape in plan view, and a reinforcing plate 26 interposed between the piezoelectric elements 34A and 34B.
Both short sides of the piezoelectric elements 34A and 34B are inclined surface portions 341 formed by so-called oblique dicing. These inclined surface portions 341 are formed symmetrically with respect to the piezoelectric element 34A and the piezoelectric element 34B with the reinforcing plate 26 interposed therebetween, whereby corner portions 35C (illustrated by two-dot chain lines) of the piezoelectric elements 34A and 34B are formed. It is chamfered. That is, the angle θ1 formed by the electrode plane portion 351 and the inclined surface portion 341 of the piezoelectric element 34A is an obtuse angle. Similarly, the angle θ2 formed by the electrode plane portion 351 and the inclined surface portion 341 of the piezoelectric element 34B is an obtuse angle.

When manufacturing such a vibrating body 23A, oblique dicing is performed on both the short side and the long side of the piezoelectric elements 34A and 34B in the above-described individualization step S2 (FIGS. 13 and 15).
Then, the insulating layer 512 is formed on each inclined surface portion 341 of the piezoelectric elements 34A and 34B and the side surface portion 261 of the reinforcing plate 26 in the insulating layer forming step S4 through the stacking step S3. At this time, since the angles θ1 and θ2 are obtuse, ink sagging is suppressed. Therefore, when the conductive patterns 415 to 419 (FIG. 6) are formed over the insulating layer 512 in the subsequent conductive portion forming step S5, the corner portions of the piezoelectric elements 34A and 34B (the portions of the chamfered angles θ1 and θ2). However, the ink is stable and the conductive patterns 415 to 419 can be easily formed.

That is, according to the present embodiment, the conduction quality of the conduction patterns 415 to 419 can be further improved, as in the second embodiment.
(9) In addition, since the inclined surface portion 341 is formed through the singulation of the piezoelectric elements 34A and 34B (individualization step S2), other processing such as cutting the piezoelectric elements 34A and 34B can be made unnecessary.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
FIG. 22 is a side sectional view of the vibrating body 24A of the piezoelectric actuator 24 in the present embodiment. The vibrating body 24A includes piezoelectric elements 30A and 30B and a reinforcing plate 27 interposed between the piezoelectric elements 30A and 30B.

  Unlike the reinforcing plate in each of the above embodiments, the reinforcing plate 27 is an insulating one formed of an insulating resin or the like. That is, in this embodiment, the insulation between the conductive patterns 415 to 419 that conduct the electrode patterns 311 to 315 (FIG. 6) formed on the electrode plane portions 351 of the piezoelectric elements 30 </ b> A and 30 </ b> B and the reinforcing plate 27 is unnecessary. Thus, the insulating layer 512 and the like in each of the embodiments are not formed on the side surface 24B of the vibrating body 24A. Conductive patterns 415 to 419 are formed directly on the side surface portion 271 of the reinforcing plate 27.

  Electrodes (not shown) formed on the back surfaces of the piezoelectric elements 30A and 30B, that is, on the surface facing the reinforcing plate 27, are connected to a reference potential circuit block outside the vibrating body 24A by any conduction means, The point that the piezoelectric elements 30A and 30B are connected in parallel is the same as in each of the above embodiments. In order to establish conduction with the electrodes (not shown) on the back surfaces of the piezoelectric elements 30A and 30B, for example, an overload is provided between the reinforcing plate 27 and the piezoelectric elements 30A and 30B near the vibration node in the vibrating body 24A. It may be possible to interpose a hang member.

According to this embodiment, in addition to the above-described effects, the following effects can be obtained.
(10) Since the insulating reinforcing plate 27 is used, it is not necessary to form an insulating layer on the short side of the vibrating body 24A in the vicinity of the vibration antinode B (FIG. 9). Efficiency can be improved.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS.
FIG. 23 is a plan view of a vibrating body 25A of the piezoelectric actuator 25 in the present embodiment, and FIG. 24 is a long side sectional view of the piezoelectric actuator 25.
The piezoelectric actuator 25 of the present embodiment is configured in substantially the same way as the piezoelectric actuator 20 (FIG. 6) of the first embodiment, but the short side surface portion 353 of the vibrating body 25A that is opposite to the protrusion 211A side. The point from which the mold member 513 which protrudes from the said side part 353 is provided differs from 1st Embodiment.

  As shown in FIGS. 23 and 24, the mold member 513 protrudes from the short side surface portion 353 of the vibrating body 25 </ b> A, and is formed in a mountain shape in the present embodiment with the short side center as a substantial center. The shape of the mold member 513 is an arbitrary shape that can function as a counter of the protrusion 211A. Further, the mold member 513 is insulative, and also functions to insulate between the conductive patterns 415 to 419 and the side surface portion 211C (FIG. 24) of the reinforcing plate 21.

  The mold member 513 is formed, for example, by discharging a mold prepared with an epoxy-based insulating resin or the like with a dispenser or the like.

According to this embodiment, in addition to the above-described effects, the following effects can be obtained.
(11) With such a mold member 513, the startability of the piezoelectric actuator 25 can be improved, and more stable driving of the piezoelectric actuator 25 can be realized.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, unlike the above embodiments, a piezoelectric actuator constituted by one piezoelectric element is shown.
FIG. 25 is a perspective view of the piezoelectric actuator 38 of the present embodiment. The vibrating body 38A in the piezoelectric actuator 38 includes a single rectangular plate-shaped piezoelectric element 380, and is configured by forming an electrode pattern, a conduction pattern, and the like on the piezoelectric element 380. The vibrating body 38A is incorporated in a device by providing a pressing plate or the like on a stepped pin (not shown) that is inserted through the through hole 380B at a substantially central plane.

  The piezoelectric element 380 has a protruding member 381 that is in contact with the rotor 28 (FIG. 23, etc.) at the approximate center of one short side. The protruding member 381 is inserted into a not-shown notch formed on the side surface of the piezoelectric element 380 and is firmly joined to the main body of the piezoelectric element 380.

On the surface of the piezoelectric element 380, a front side electrode 390 having Ni as a base layer and Au as an upper layer is formed. The electrode 390 is divided by engraving the groove 390A, and is formed on electrode patterns 391 to 394 corresponding to regions divided into approximately four portions in the vertical and horizontal directions, and on a part on the short side opposite to the protrusion 381 side. A partitioned partial electrode 395 is formed.
The electrode patterns 391 to 394 are respectively paired on the diagonal line of the piezoelectric element 380, the electrode patterns 391 and 394 are electrically connected to each other by the conductive pattern 441, and the electrode patterns 392 and 393 are electrically connected to the conductive pattern 442. They are connected to each other and have the same potential. Note that portions where these conductive patterns 441 and 442 overlap with electrode patterns having different potentials are insulated by forming insulating layers 521 and 522.

On the other hand, a back side electrode 396 similar to the electrode 390 is also formed on the entire back surface side of the piezoelectric element 380. The piezoelectric element 380 is polarized in the thickness direction, and expands and contracts in the plane direction due to a piezoelectric lateral effect when a voltage is applied between the front side electrode 390 and the back side electrode 396.
Here, the partial electrode 395 and the back side electrode 396 are set to the same potential by the conductive pattern 443 passing through the side surface portion 382 of the piezoelectric element 380.

  With such a configuration, when the piezoelectric element 380 is conductively mounted, it is only necessary to establish conduction with respect to each electrode formed on the front side of the piezoelectric element 380, and it is not necessary to establish direct conduction with the back side electrode 396. Thus, since it is only necessary to conduct electricity only to the front side of the piezoelectric element 380, the direction of conduction mounting is aligned in the same direction. Thereby, even after the vibrating body 38A is incorporated in the support body or the like, the conduction work to the external circuit board can be easily performed. Further, since the conductive patterns 441 to 443 and the like need only be provided on the front side of the piezoelectric element 380, the thickness of the entire vibrating body 38A can be further reduced.

All of the conductive patterns 441 to 443 are formed by the inkjet method described above. The insulating layers 521 and 522 are also formed by the inkjet method in the same manner.
The conductive pattern 443 is formed on the body surface portion 35 of the piezoelectric element 380 including the electrode plane portion 385 on which the electrode 390 is formed, the side surface portion 386 of the piezoelectric element 380, and the electrode plane portion 387 on which the electrode 396 is formed. ing.
In the present embodiment, the side surface portion 386 of the piezoelectric element 380 is provided with a mold member 514, the corner portion 386 </ b> A between the side surface portion 386 and the electrode flat surface portion 385, and the side surface portion 386 and the electrode flat surface portion 387. The sharpness in each of the corner portions 386B between the two is relaxed. As a result, when the conductive pattern 443 is formed, the ink at the corners 386A and 386B is stabilized, and the conductive pattern 443 can be easily formed.
Instead of providing such a mold member 514, for example, chamfering the corner portions 386A and 386B of the piezoelectric element 380 is also effective.

  In this embodiment, each of the electrode pattern 391 (or 394), the electrode pattern 392 (or 393), and the partial electrode 395 requires conduction means (three systems) to the outside of the vibrating body 38A. Means are arbitrary. For example, these three systems may be electrically connected to a lead substrate (not shown) disposed in the vicinity of the piezoelectric element 380 by a wire, an overhang, or the like, and the lead substrate may be electrically connected to a voltage applying device in the circuit substrate. Instead of such a lead substrate, a pin inserted into the through hole 380B may be used, and these three systems of lead wires, wires, etc. may be put on the outer peripheral surface of this pin. Alternatively, it is also conceivable to form a conductive pattern continuous with the conductive patterns 441, 442, 443 on the outer peripheral surface of the pin by inkjet or the like.

  The operation of the piezoelectric actuator 38 is substantially the same as that of the piezoelectric actuator 20 of each of the embodiments described above. Either one of the electrode patterns 391, 394 or the electrode patterns 392, 393 is selected and the back side electrode 396 is selected. By applying a voltage, it vibrates in a mixed mode of longitudinal primary vibration and bending secondary vibration. Depending on the selection of the electrode pattern 391, 394 or the electrode pattern 392, 393, the direction of the elliptical orbit of the protrusion 381 is switched, and the driven body such as the rotor 28 is driven in the forward direction and the reverse direction.

  This embodiment is common to the configuration of the first embodiment in that the electrodes formed on the front side and the back side of the vibrating body are made conductive by a conductive pattern, and this conductive pattern is formed by inkjet. Therefore, there are substantially the same effects as in the first embodiment.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described with reference to FIGS.
FIG. 26 is a side sectional view of the piezoelectric actuator 36 in the present embodiment. The piezoelectric actuator (ultrasonic motor) 36 includes a disk-shaped elastic body 360 on which the piezoelectric elements 361 are stacked, and a holding body 365 that supports and supports the elastic body 360. The holding body 365 includes the elastic body 360 and the holding body 365. A rotor 368 as a driven body provided coaxially is rotationally driven. In the piezoelectric actuator 36, a vibrating body 36 </ b> A is configured by the elastic body 360, the piezoelectric element 361, and the holding body 365.

The rotor 368 is provided with a spring member 369 via a pivot 369P, and the vibrating member 36A and the rotor 368 are assembled by the spring member 369 while being pressed against each other.
Note that a hole stone 365B is provided around the distal end portion 365A of the holding body 365 on which the rotor 368 is pivoted to reduce the frictional resistance when the rotor 368 rotates.

The elastic body 360 is made of a conductive material, and protrusions 360A are formed on the surface of the elastic body 360 opposite to the piezoelectric element 361 so as to protrude at equal intervals in the circumferential direction. These protrusions 360 </ b> A are in contact with the rotor 368.
Further, as shown in FIG. 27, a cutout 360 </ b> B that opens to the piezoelectric element 361 side is formed in a part of the outer peripheral portion of the elastic body 360.
The holding body 365 is subjected to a surface treatment for ensuring insulation.

FIG. 28 is a perspective view showing the elastic body 360 from the holding body 365 side. FIG. 29 is a plan view showing the piezoelectric element 361 provided on the elastic body 360.
The piezoelectric element 361 has a circular plate shape, and electrodes 3611 and 3612 (FIG. 27) formed by plating, sputtering, vapor deposition, or the like are formed on both front and back surfaces of the piezoelectric element 361. The electrode 3611 on the side not laminated with the elastic body 360 is roughly divided into a first electrode 362A and a second electrode 362B by a groove 362D formed by etching or the like, as shown in FIG. A partial electrode 362C in which a part of the outer peripheral portion of the conductive film is partitioned is formed.
The first electrode 362A has a shape in which every other region obtained by dividing the piezoelectric element 361 into eight equal parts in the radial direction is connected on the shaft portion 361Z side inside the groove 362D, and the second electrode 362B is formed outside the groove 362D. Thus, every other region obtained by dividing the piezoelectric element 361 into eight equal parts in the radial direction is connected to the outer peripheral portion 361Y side. In addition, it is not restricted to 8 division of this embodiment, For example, 6 division, 10 division, 12 division, etc. may be sufficient.

In such first and second electrodes 362A and 362B, conductive patterns 421 and 422 are formed on the shaft portion 361Z side of the piezoelectric element 361 as shown in FIGS. The first and second electrodes 362A and 362B are led out of the piezoelectric actuator 36 by the conductive patterns 421 and 422 through the body surface portion of the holding body 365, respectively. These conduction patterns 421 and 422 are finally conducted to a drive control device mounted on a circuit board (not shown).
Further, the partial electrode 362 </ b> C and the electrode 362 </ b> B on the side laminated with the elastic body 60 are electrically connected to each other by the conductive pattern 423 through the outer peripheral side surface of the piezoelectric element 361. Although not shown, this partial electrode 362C is provided with any conduction means such as a wire, and the reference potential on the circuit board is supplied to the elastic body 360 through this partial electrode 362C. With such a configuration, the elastic body 360 and the electrode 3612 (FIG. 27) are used as a common electrode for the first and second electrodes 362A and 362B, and between the first electrode 362A and the elastic body 360 and between the second electrode 362B and the elastic body. A voltage is applied to the piezoelectric elements 361 between the bodies 360.

As shown in FIG. 28, the conductive patterns 421 and 422 extend from the electrode plane portion 3620 on which the first and second electrodes 362A and 362B are formed, along the outer peripheral surface 365C of the shaft portion 365Z of the holding body 365, respectively. Further, it is formed along the surface 365D of the base portion 365X of the holding body 365.
Note that the position of the shaft portion 365Z of the holding body 365 corresponds to a position in the vicinity of a node of respiratory vibration (described later) in the substantially disk-shaped vibrating body 36A, and the conductive patterns 421 and 422 are wired in the vicinity of this node. The influence of the formation of the conductive patterns 421 and 422 on the vibration of the vibrating body 36A is suppressed.

  Further, a three-dimensional chamfered three-dimensional R-shaped chamfered portion 365E is formed on the surface portion of the base portion 365X through which the conductive patterns 421 and 422 pass. Furthermore, insulating mold members 515A and 515B are provided in a fillet shape inside the electrode flat surface portion 3620 and the outer peripheral surface 365C of the shaft portion of the holder 365.

Here, also in the present embodiment, the conductive patterns 421, 422, and 423 are formed by ink jetting, and the formation of the conductive patterns 421 to 423 is performed after the piezoelectric element 361 is stacked on the elastic body 360. When the conductive pattern 423 is formed, ink is ejected to the body surface portion 35 of the piezoelectric element 361 including the side surface portion 361C of the piezoelectric element 361 through the notch 360B of the elastic body 360.
Also, the conductive patterns 421 and 422 can be stably formed by the mold members 515A and 515B and the chamfered portion 365E.

By the way, as shown in FIG. 29, the piezoelectric element 361 has a configuration in which the portions 362a of the first electrode 362A and the portions 362b of the second electrode 362B are arranged along the circumferential direction. As shown, the polarization process is alternately performed in the same direction for every two parts 362a and 362b. That is, the polarization directions in the adjacent regions among the four regions 369A to 369D divided along the radial direction of the piezoelectric element 361 are opposite to each other. For example, the charge direction in one region is the surface of the piezoelectric element 361 (the electrode plane). Portion 3620) to the back surface (the side on which the elastic body 360 is provided), the charge direction in the other region is set in the direction from the back surface to the front surface.
A total of four protrusions 360A are arranged at the boundaries of the regions 369A to 369D.

Hereinafter, the operation of the piezoelectric actuator 36 will be described.
FIG. 30 is a schematic diagram showing the operation of the piezoelectric actuator 36. The piezoelectric actuator 36 selectively drives the rotor 368 in both the forward direction shown in FIG. 30A and the reverse direction shown in FIG. 30B by selectively using the first and second electrodes 362A and 362B. It is possible. That is, the drive control device (not shown) is configured to be able to switch the power supply to the first and second electrodes 362A and 362B that are conducted through the conduction patterns 421 and 422.

  FIG. 30A shows a case where an AC voltage is applied to the piezoelectric element 361 between the first electrode 362A and the elastic body 360 to drive the rotor 368 in the positive direction. When only the first electrode 362A is to be applied with voltage, the second electrode 362B restrains against spreading vibration (breathing vibration) to both ends in the radial direction of the piezoelectric element 361 generated in the portion where the first electrode 362A is formed. Flexural vibrations are induced by the force and the polarization treatment described above. This bending vibration behaves like a solid line and a two-dot chain line schematically showing the elastic body 360 in FIG. 30A. At this time, a locus drawn by the protrusion 360A of the elastic body 360 is indicated by an arrow. The rotor 368 is driven in a direction tangential to the protrusion 360A.

  On the other hand, FIG. 30B shows a case where an AC voltage is applied to the piezoelectric element 361 between the second electrode 362B and the elastic body 360 to drive the rotor 368 in the reverse direction. When only the second electrode 362B is a voltage application target, bending vibration that bends with respect to respiratory vibration of the piezoelectric element 361 is induced by the restraining force in the first electrode 362B and the polarization treatment described above. The phase of this bending vibration is different from that in FIG. 30A, and the locus drawn by the protrusion 360A by this bending vibration is indicated by an arrow. The rotor 368 is driven in a direction tangential to the protrusion 360A. This bending vibration behaves like a solid line and a two-dot chain line showing the elastic body 360 in FIG. 30B, and the locus drawn by the protrusion 360A of the elastic body 360 is indicated by an arrow. The rotor 368 is driven in a direction tangential to the protrusion 360A.

As described above, the protrusion 360A arranged at the boundary between the first and second electrodes 362A and 362B converts the vibration of the vibrating body 36A into the rotational motion of the rotor.
Here, since the elastic body 360 and the piezoelectric element 361 do not rotate, and the positions of the nodes and the antinodes of the bending vibration are not changed as shown in the figure, the piezoelectric actuator 36 is a standing wave drive system.

The piezoelectric actuator 36 of the present embodiment is different in shape and structure from the piezoelectric actuators of the above embodiments, but is the same in that a conducting portion that conducts an electrode formed on the piezoelectric element is formed by inkjet. This configuration produces substantially the same effect as described above.
In other words, the formation of the conductive patterns 421 to 423 does not make the conductive mounting in the piezoelectric element 361 bulky, and can facilitate downsizing and thinning and can also be easily manufactured. In addition, since the vibration patterns can be reduced as much as possible due to the integration of the conductive patterns 421 to 423, the piezoelectric element 361, and the holding body 365, the vibration energy efficiency can be improved.
Furthermore, since the first and second electrodes 362A and 362B and the partial electrode 362C are formed on one surface of the piezoelectric element 361, only the first and second electrodes 362A and 362B and the partial electrode 362C can be electrically connected. It is sufficient that the opposite electrode 362B is not electrically connected. As described above, since the direction of the conductive mounting is one direction, the work related to the conductive mounting is easy, and since the conductive mounting can be arranged only on one side of the piezoelectric element 361, the entire piezoelectric actuator 36 can be downsized.

[Eighth Embodiment]
Next, an eighth embodiment of the present invention will be described with reference to FIGS.
FIG. 31 is a side sectional view of the piezoelectric actuator 37 in the present embodiment. The piezoelectric actuator (ultrasonic motor) 37 is similar in structure to the piezoelectric actuator 36 according to the seventh embodiment. However, unlike the piezoelectric actuator 36, a traveling wave driving system is employed.

The piezoelectric actuator 37 includes an annular conductive elastic body 370 on which the piezoelectric elements 371 are stacked, and a holding body 365 that pivotally supports the elastic body 370, and is provided on the holding body 365 coaxially with the elastic body 370. The rotor 368 as the driven body is driven to rotate. In the piezoelectric actuator 37, the elastic body 370, the piezoelectric element 371, and the holding body 365 constitute a vibrating body 37 </ b> A.
On the surface of the elastic body 370, a friction material 370A for ensuring appropriate friction with the rotor 368 is laminated.

FIG. 32 is a plan view of the piezoelectric element 371. In the piezoelectric element 371, a plurality of electrodes 372A to 372N are formed by dividing a conductive film formed by plating or the like along the radial direction. Of these, a portion where the electrodes 372A to 372L are formed 32, as shown by + and-in FIG. 32, the adjacent ones are polarized in the thickness direction so as to have opposite polarities.
A partial electrode 372P is formed on a part of the outer periphery of the piezoelectric element 371. In the piezoelectric element 371, an electrode 372Q is formed over substantially the entire surface on the side opposite to the side where the electrodes 372A to 372N are formed (FIG. 33).

A conductive pattern 431 extending over the electrodes 372A to 372F is formed on the electrode flat surface portion 3720 of the piezoelectric element 371. The conductive pattern 431 extends along the outer peripheral surface 365C of the shaft portion 365Z of the holding body 365, and the surface of the base portion 365X. It is formed to extend to 365D.
Similarly, a conductive pattern 432 extending over the electrodes 372G to 372L is formed in the electrode plane portion 3720 of the piezoelectric element 371, and the conductive pattern 432 is also the electrode plane portion 3720 and the outer peripheral surface of the shaft portion 365Z in the same manner as the conductive pattern 431. 365C and the surface 365D of the base portion 365X.
In addition, as shown in FIG. 33, a conductive pattern 433 is formed to connect the electrode 372Q and the partial electrode 372P through the side surface portion 371C of the piezoelectric element 371. The elastic body 370 has a notch 370 </ b> B that serves as a relief when the conductive pattern 433 is formed.

These conductive patterns 431 to 433 are formed by an ink jet method, and the electrodes 372A to 372F are electrically connected to each other by the conductive pattern 431 and drawn out of the piezoelectric element 371. The electrodes 372G to 372L are mutually connected by the conductive pattern 432. It is conducted and pulled out of the piezoelectric element 371. These conduction patterns 431 and 432 are finally conducted to a drive control device mounted on a circuit board (not shown).
Further, the electrode 372Q and the partial electrode 372P, which are set to the same potential by the conductive pattern 433, are electrically connected to the outside by using any conductive means such as a wire on the partial electrode 372P formed on the same surface as the electrodes 372A to 372L. Conduct externally.

In such a piezoelectric actuator 37, the first and second electrode groups 379A and 379A configured by the electrodes 372A to 372F and the second electrode group 379B configured by the electrodes 372G to 372L are respectively substantially 90 by a drive control device (not shown). Supply AC voltage with a phase difference of °. Thereby, the standing wave generated by the voltage application between the first electrode group 379A and the elastic body 370 and the standing wave generated by the voltage application between the second electrode group 379B and the elastic body 370 are combined, A deflection traveling wave that travels in the circumferential direction of the elastic body 370 is generated on the surface of the elastic body 370. At this time, the rotor 368 is driven in the direction opposite to the traveling direction of the traveling wave by friction with the friction material 370A.
The drive control device switches the phase difference between the drive voltages supplied to the first and second electrode groups 379A and 379B to + 90 ° or −90 °, whereby the rotor 368 is driven in both the forward direction and the reverse direction.

  The present embodiment is also the same as the above embodiments in that the conductive part that conducts the electrodes formed on the piezoelectric element is formed by inkjet, and this configuration has substantially the same effect as the above embodiments. Play.

[Ninth Embodiment]
Next, a ninth embodiment of the present invention will be described with reference to FIGS. This embodiment shows an example of incorporation into an electronic timepiece that is an electronic device.

[1. overall structure]
FIG. 34 is an external view of the electronic timepiece 7 according to the present embodiment. The electronic timepiece 7 includes a movement 131 as a timekeeping portion and a dial 132, hour hand 133, minute hand 134 and second hand 135 as a timekeeping information display portion for displaying hour, minute and second, as well as a window provided on the dial 132. It is a wristwatch provided with a date display device 140 that displays the date from the section 132A.

[2. Configuration of date display device]
FIG. 35 is a plan view showing the date display device 140 supported by the bottom plate 131A. The date display device 140 includes a piezoelectric actuator 20 (FIG. 3) according to the first embodiment, a rotor 28 as a driven body that is rotationally driven by the piezoelectric actuator 20, and a reduction wheel that transmits the rotation of the rotor 28 while reducing the rotation. The vehicle is generally configured to include a row 141 and a date wheel 142 that is rotated by a driving force transmitted through the reduction wheel train 141.
The rotor 28 is rotationally driven by the piezoelectric actuator 20 at the turn of the day or at the time of date correction. In the present embodiment, a spring member 281 that biases the rotor 28 toward the vibrating body 20A of the piezoelectric actuator 20 is provided.
The reduction wheel train 141 includes a gear 1411 that is arranged coaxially with the rotor 28 and rotates integrally with the rotor 28, a date turning intermediate wheel 1412 that meshes with the gear 1411, and a date turning wheel 1413.

  Below the bottom plate 131A (behind) is a stepping motor (not shown) that operates with a pulse signal oscillated by a crystal resonator, and a hand movement that is connected to the stepping motor to drive the hour hand 133, the minute hand 134, and the second hand 135. A train wheel (not shown), a battery 131B, and the like are provided. The battery 131B supplies power to each circuit such as a stepping motor, the piezoelectric actuator 20, and a drive circuit (not shown) that applies an AC voltage to the piezoelectric actuator 20.

  The date indicator driving intermediate wheel 1412 includes a large diameter portion 1412A and a small diameter portion 1412B. The small-diameter portion 1412B has a cylindrical shape slightly smaller in diameter than the large-diameter portion 1412A, and a substantially square-shaped notch portion 1412C is formed on the outer peripheral surface thereof. The small diameter portion 1412B is fixed so as to be concentric with the large diameter portion 1412A. Since the gear 1411 on the upper portion of the rotor 28 is engaged with the large diameter portion 1412 </ b> A, the intermediate date wheel 1412 rotates in conjunction with the rotation of the rotor 28.

  A leaf spring 1414 is provided on the bottom plate 131A on the side of the intermediate date wheel 1412. A base end portion of the leaf spring 1414 is fixed to the bottom plate 131A, and a distal end portion is bent into a substantially V shape. Has been. The tip of the leaf spring 1414 is provided so as to be able to enter and leave the notch 1412C of the intermediate date wheel 1412. A contact 1415 is disposed at a position close to the leaf spring 1414. The contact 1415 is moved when the intermediate date wheel 1412 rotates and the tip of the leaf spring 1414 enters the notch 1412C. It comes into contact with the spring 1414. A predetermined voltage is applied to the leaf spring 1414, and when the leaf spring 1414 contacts the contact 1415, the voltage is also applied to the contact 1415. Therefore, by detecting the voltage of the contact 1415, the date feeding state can be detected, and the amount of rotation of the date indicator 142 for one day can be detected.

  The rotation amount of the date dial 142 is not limited to that using the leaf spring 1414 or the contact 1415, but the rotation amount of the rotor 28 or the date turning intermediate wheel 1412 is detected and a predetermined pulse signal is output. Specifically, various rotary encoders such as known photo reflectors, photo interrupters, and MR sensors can be used.

  The date dial 142 has a ring shape, and an internal gear 1421 is formed on the inner peripheral surface thereof. The date indicator driving wheel 1413 has a five-tooth gear and meshes with the internal gear 1421 of the date indicator 142. A shaft 1413A is provided at the center of the date driving wheel 1413, and the shaft 1413A is loosely inserted into a through hole 131C formed in the bottom plate 131A. The through hole 131 </ b> C is formed long along the circumferential direction of the date dial 142. The date indicator driving wheel 1413 and the shaft 1413A are urged in the upper right direction in FIG. 35 by a leaf spring 1413B fixed to the bottom plate 131A. The urging action of the leaf spring 1413B prevents the date dial 142 from swinging.

[3. Configuration of piezoelectric actuator]
FIG. 36 is a partially enlarged view of FIG.
The piezoelectric actuator 20 is activated at the change of date or at the time of date correction, and drives the rotor 28 by being supplied with an AC voltage by a drive circuit (not shown).
Note that all the piezoelectric actuators described above can be incorporated into the date display device 140 of the present embodiment.

According to this embodiment, in addition to the above-described effects, the following effects can be obtained.
(12) The electronic timepiece 7 employs the piezoelectric actuator 20 instead of a general stepping motor or the like as driving means in the timepiece, and is not affected by magnetism. Furthermore, it is possible to enjoy advantages such as high responsiveness, fine feed, advantageous for downsizing and thinning, high torque, and large holding torque (the rotor position is maintained even when no power is supplied).

(13) Further, since the piezoelectric actuator 20 is particularly thin, it is suitable for incorporation into a timepiece where thinning is a major issue, and a large displacement is obtained at a low voltage by parallel connection in the piezoelectric elements 30A and 30B. Therefore, a configuration suitable for a portable device driven by a battery such as a watch can be obtained.

[Modification of the present invention]
Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. In addition, the manufacturing method of the piezoelectric element and the manufacturing method of the vibrating body of the present invention can be applied to these manufacturing apparatuses.

The gist of the present invention is to form the conductive portion directly on the body surface portion of the piezoelectric element using a liquid material containing conductive particles at room temperature. In addition to the inkjet method exemplified in the embodiment, tampo (pat) printing, screen printing, application by a dispenser, and the like can be exemplified.
Further, as with the conductive portion, the present invention also includes forming the insulating layer by an ink jet method using a liquid insulator, tampo (pat) printing, screen printing, application by a dispenser, or the like.
In each of the above embodiments, the insulating layer is also formed on the surfaces of the arm portions 212 and 213 of the reinforcing plate by inkjet. However, in the present invention, the insulating layers are formed on the arm portions 212 and 213 by other means. May be. That is, surface processing for ensuring insulation may be separately performed on the arm portions 212 and 213, or an insulating sheet or the like may be installed on the surfaces of the arm portions 212 and 213.

In the above-described embodiment, the vibrating body having the pair of arm portions 212 and 213 and fixed to the support member or the like on both sides is shown. However, the present invention is not limited to this, and the vibrating body of the present invention is supported and fixed on one side. May be. In this case, the abutting portion (projection) draws one elliptical orbit by shifting the position of the abutting portion (projection) with the driven body in the width direction to the side opposite to the side where the support is fixed. The driven body may be sent in one direction. Here, the electrodes on the front surface and the back surface of the piezoelectric element may not be divided.
Further, regarding the incorporation of the piezoelectric actuator into an electronic device, biasing means such as a spring may be provided on the piezoelectric actuator or the rotor, and the contact between the contact portion (protrusion) of the piezoelectric actuator and the rotor may be pressurized. Here, a slide may be used as the biasing means, that is, the piezoelectric actuator may be slidably held by the slider and may be assembled to the support member.

  In each of the above embodiments, a piezoelectric element that vibrates when an AC voltage is applied is exemplified. However, a displacement of the piezoelectric element when a DC voltage is applied may be used. As such an example, a piezoelectric valve to which a DC voltage is applied can be cited.

  Furthermore, the layout of the electrode pattern of the piezoelectric actuator, the arrangement of the conductive pattern, the lamination mode of the piezoelectric elements and the reinforcing plate, the number of piezoelectric elements laminated on the reinforcing plate, and the like can be arbitrarily configured. The displacement direction of the piezoelectric element may be appropriately set according to the polarization direction and the direction of the electric field, and may exhibit a piezoelectric longitudinal effect, a piezoelectric transverse effect, a piezoelectric thickness shear effect, or the like.

  The reinforcing plate is not essential and can be used alone. In this case, a contact portion with the driven body is integrally formed on the piezoelectric element, a protruding member formed separately is fixed to the piezoelectric element, or a rectangular shape of the piezoelectric element is formed. What is necessary is just to contact | abut a part to a to-be-driven body.

The present invention is not limited to those applied to the printer and the electronic timepiece of the embodiment, but can be applied to various electronic devices, and is particularly suitable for portable electronic devices that are required to be downsized.
Here, examples of various electronic devices include a phone having a clock function, a mobile phone, a non-contact IC card, a personal computer, a personal digital assistant (PDA), a camera, and the like.
The present invention can also be applied to electronic devices such as a camera without a clock function, a digital camera, a video camera, and a mobile phone with a camera function. When applied to these electronic devices having a camera function, the piezoelectric actuator of the present invention can be used to drive a lens focusing mechanism, a zoom mechanism, an aperture adjustment mechanism, and the like.
Further, the driving mechanism of meter pointers of measuring instruments, the driving mechanism of instrument pointers of instrument panels of automobiles, etc., the piezoelectric vibrators of inkjet heads used in piezoelectric buzzers, printers, etc. (also the piezoelectric vibrator 114 of FIG. 13). Yes), paper feed mechanism of printer, drive mechanism and posture correction mechanism of movable toys such as vehicles and dolls, ultrasonic motor, hard disk drive, ultrasonic cleaner, ultrasonic humidifier, ultrasonic welding / welding device, ultra The piezoelectric actuator of the present invention may be used in a sonic therapy device, an ultrasonic cutter, a tube pump, or the like.

Moreover, in the said embodiment, although the piezoelectric actuator 20 was used for the drive of the display apparatus which shows a calendar | calendar, you may use the piezoelectric actuator of this invention for the drive of the hand which shows not only this but the time information measured. .
In each of the above embodiments, a wristwatch is shown as an application example of a piezoelectric actuator. However, the present invention is not limited to this, and the present invention can also be applied to a pocket watch, a table clock, a wall clock, and the like. In these various timepieces, for example, it can be used as a mechanism for driving a mechanism doll or the like.

  In each of the above embodiments, a piezoelectric actuator that uses a piezoelectric element as a driving device has been described. However, the usage range of the piezoelectric element is not limited to this, and a voltage that indicates the state of distortion (displacement) of the piezoelectric element due to the positive piezoelectric effect. Informational use of signals, for example, underwater communication devices (sonar), fish detectors (deepening devices), distance meters, nondestructive inspection devices (ultrasonic flaw detectors), ultrasonic diagnostic equipment, ultrasonic thickness gauges, flow meters Piezoelectric elements can also be used for such as.

The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

1 is a schematic diagram of a printer according to a first embodiment of the present invention. The perspective view of the piezoelectric actuator unit in the said embodiment. The perspective view of the piezoelectric actuator in the said embodiment. The long side sectional view of the piezoelectric actuator in the embodiment. The short side sectional view of the piezoelectric actuator in the embodiment. The top view which shows the wiring of the piezoelectric actuator in the said embodiment. The perspective view which shows the side surface of the vibrating body in the said embodiment. Sectional drawing which shows the insulating layer by the side of the vibrating body in the said embodiment. The schematic diagram shown about the bending vibration of the vibrating body in the said embodiment. FIG. 2 is a cross-sectional perspective view showing a part of the ink jet head in the embodiment. The expanded sectional view of the nozzle of the ink-jet head. Sectional drawing which shows the droplet discharge of the said nozzle. The flowchart which shows the manufacturing process of the vibrating body in the said embodiment. The figure which shows the electrode formation process with respect to the base material in the said embodiment. The elements on larger scale of FIG. FIG. 16 is a side sectional view of the base material shown in FIG. 15. The figure shown about the lamination process in the said embodiment. The figure shown about the insulating layer formation process in the said embodiment. The figure shown about the conduction | electrical_connection part formation process in the said embodiment. The short side sectional view of the piezoelectric actuator in a 2nd embodiment of the present invention. The short side sectional view of the piezoelectric actuator in a 3rd embodiment of the present invention. The short side sectional view of the piezoelectric actuator in a 4th embodiment of the present invention. The top view of the piezoelectric actuator in 5th Embodiment of this invention. The long side sectional view of the piezoelectric actuator in the embodiment. The perspective view of the piezoelectric actuator in 6th Embodiment of this invention. The sectional side view of the piezoelectric actuator in 7th Embodiment of this invention. The elements on larger scale of FIG. The perspective view which shows the piezoelectric element and elastic body in the said embodiment. The top view which shows the electrode plane part of the piezoelectric element in the said embodiment. The schematic diagram which shows operation | movement of the piezoelectric actuator in the said embodiment. The sectional side view of the piezoelectric actuator in 8th Embodiment of this invention. The top view which shows the electrode plane part of the piezoelectric element in the said embodiment. The elements on larger scale of FIG. The external view of the timepiece in 9th Embodiment of this invention. The top view which shows the date display apparatus in the said embodiment. The elements on larger scale of FIG. The figure which shows the piezoelectric actuator of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer (electronic device), 5 ... Paper feed roller, 7 ... Electronic timepiece (electronic device), 11E ... Recessed part, 20 ... Piezoelectric actuator, 20A ... Vibrating body, 20B ... Side part (side part of vibrating body), 21 ... reinforcing plate, 22 ... piezoelectric actuator, 22A ... vibrating body, 22B ... side part, 23 ... piezoelectric actuator, 23A .. Vibrating body, 24... Piezoelectric actuator, 24A... Vibrating body, 24B... Side surface part, 25... Piezoelectric actuator, 25A. Reinforcing plate, 28 ... rotor (driven body), 30A, 30B ... piezoelectric element, 30 ... piezoelectric element, 33A, 33B ... piezoelectric element, 34A, 34B ... piezoelectric element, 35 ... Body surface part, 35C ... Corner, 36 Piezoelectric actuator, 36A ... vibrating body, 37 ... piezoelectric actuator, 37A ... vibrating body, 38 ... piezoelectric actuator, 38A ... vibrating body, 110 ... inkjet head, 120 ... Ink (liquid or liquid insulator), 131... Movement (time measuring means), 132... Dial (time information display section), 133... Hour hand (time information display section), 134. Minute hand (time information display part), 135... Second hand (time information display part), 201... Recess, 211 A... Projection, 211 C .. side part (reinforcement plate side part), 261. Part, 271 ... side part, 311 to 315 ... electrode pattern, 331 ... step part, 341 ... inclined face part, 351 ... electrode flat part, 353 ... short side part (piezoelectric) Element side) 361 ... Piezoelectric element, 361C ... Side face, 362A, 362B ... Electrode, 362C ... Partial electrode, 368 ... Rotor (driven body), 371 ... Piezoelectric element, 371C ... Side surface, 372A to 372N ... electrode, 372Q ... electrode, 372P ... partial electrode, 380 ... piezoelectric element, 381 ... projection member, 380A ... vibrating body, 385 ... Electrode plane part, 386 ... side part, 386A, 386B ... corner part, 387 ... electrode plane part, 390 ... electrode, 391-394 ... electrode pattern, 395 ... partial electrode, 396 ... back side electrode, 411-419 ... conduction pattern, 421-423 ... conduction pattern, 431-433 ... conduction pattern, 441-443 ... conduction pattern, 511, 512 ... absolute Edge layer, 513 ... mold member, 514 ... mold member, 515A, 515B ... mold member, 521,522 ... insulating layer, A ... node, S1 ... electrode forming step, S5 ... Conducting part forming step.

Claims (14)

A piezoelectric element having a substantially plate shape and electrodes formed on the front surface portion and the back surface portion,
A partial electrode is formed on a part of either the front surface portion or the back surface portion,
A conductive portion is formed that electrically connects the partial electrode and the electrode formed on the side opposite to the side where the partial electrode is formed through the piezoelectric element side surface portion,
The conducting portion contains conductive particles at room temperature on the body surface portion of the piezoelectric element including the partial electrode and the electrode plane portion on which the electrodes are respectively formed and the piezoelectric element side surface portion. After the liquid material is provided, the liquid material is dried and solidified at a temperature higher than normal temperature to form the conductive particles in contact with each other. Two piezoelectric elements having a substantially plate shape and electrodes formed on at least one of the front surface portion and the back surface portion are laminated,
Each of the laminate surface portion and the laminate back surface portion on both sides in the lamination direction of the laminate by the piezoelectric element is an electrode plane portion on which the electrode is formed,
On the body surface portion of the laminate including one of the electrode plane portions, each piezoelectric element side surface portion of each of the piezoelectric elements, and the other of the electrode plane portions, the electrodes in the electrode plane portions are electrically connected to each other. A conductive portion connected to the
The conducting portion is formed by providing a liquid material containing conductive particles at normal temperature on the body surface portion, and then bringing the liquid material into contact with each other by drying and solidifying the liquid material at a temperature higher than normal temperature. A vibrating body characterized by The vibrator according to claim 2,
A conductive reinforcing plate interposed between the piezoelectric element and the piezoelectric element;
The body surface portion includes the reinforcing plate side surface portion,
An insulating layer is interposed between the conduction portion and the side surface portion of the reinforcing plate. The vibrating body according to claim 3,
The insulating layer is formed by providing an insulator that is liquid at room temperature on the side surface of the reinforcing plate, and then drying and solidifying the insulator at a temperature higher than room temperature. The vibrating body according to claim 4,
The vibrating body is characterized in that a concave portion that is recessed in a direction intersecting the stacking direction is formed on the side surface of the reinforcing plate. The vibrating body according to claim 4,
A step portion having a substantially L-shaped cross section is formed at a corner portion between the electrode plane portion and the side surface portion of the piezoelectric element. The vibrating body according to claim 4,
A corner portion between the electrode plane portion and the side surface portion of the piezoelectric element is chamfered obliquely with respect to the thickness direction of the piezoelectric element. The vibrator according to claim 2,
An insulating reinforcing plate interposed between the piezoelectric element and the piezoelectric element;
The body surface portion includes the reinforcing plate side surface portion. A vibration body according to any one of claims 1 to 8,
A piezoelectric actuator, wherein the driven body is driven by transmitting the vibration of the vibrating body to the driven body. The vibrator according to any one of claims 3, 5, and 8, comprising:
A piezoelectric actuator that drives the driven body by transmitting the vibration of the vibrating body to the driven body,
A protrusion projecting toward the driven body is formed on a side surface portion of the reinforcing plate,
A piezoelectric actuator characterized in that an insulating mold member is provided between the side surface portion and the conducting portion on the side surface portion of the reinforcing plate opposite to the side on which the protrusion is formed. . An electronic device comprising any one of the vibrator according to claim 1 and the piezoelectric actuator according to claims 9 and 10. The electronic device according to claim 11 is:
An electronic device, comprising: a timepiece; and a timepiece information display section for displaying information timed by the timepiece. An electrode forming step of forming a plurality of electrodes on each of the piezoelectric elements constituting the vibrating body;
After providing a liquid material containing conductive particles at room temperature on the body surface portion of the vibrating body including the side surface portion of the piezoelectric element, the conductive particles are mutually solidified by drying and solidifying the liquid material at a temperature higher than normal temperature. And a conductive part forming step of forming a conductive part for bringing the electrodes into electrical contact with each other. In the manufacturing method of the vibrator according to claim 13,
In the conducting part forming step, the conducting part is formed by ejecting ink as the liquid material onto the body surface part.

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