JP2002100820A - Electrochemical transducer, mechano-electrical transducer, ultrasonic motor, piezoelectric transformer and electronic apparatus with ultrasonic motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized electromechanical transducer which can extract energy of high output with little consumption power. SOLUTION: A piezoelectric element 1 is polarized in the thickness direction. A protruding member 2a is formed in the element 1. A first electrode 8, divided by a wavelength different from a wavelength which the element 1 drives, is formed on the surface of the element 1, where the protruding member 2a is formed. A second electrode 9, divided by the same wavelength as the first electrode 8, is formed on the surface of the element 1, which faces the surface where the protruding member 2a is formed. The second electrode 9 is positioned by shifting a prescribed interval, when the electrode 9 is overlapped in planar manner with the first electrode 8. An electric field is applied to either the first electrode 8 or the second electrode 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy conversion element using a piezoelectric element and a method for driving the energy conversion element. Further, the present invention relates to an electronic device using the energy conversion element. For example, a piezoelectric device, that is, an actuator, a sensor, a transformer, a buzzer, a speaker, a filter, and the like, and an electronic device using the piezoelectric device, and the like.

[0002]

2. Description of the Related Art In recent years, various piezoelectric devices (eg, actuators, sensors, transformers, filters, etc.) have been actively used in various electronic devices. For example, among motor actuators, ultrasonic motors have attracted attention, and applications in various fields have been attempted. As a driving method of the ultrasonic motor, a method of bonding a piezoelectric element to a plate-shaped vibrating body and converting expansion and contraction motion (by the piezoelectric transverse effect) of the piezoelectric element into bending vibration is generally widely used. For example, Japanese Patent Publication No. 8-1076
86 describes an example of such an ultrasonic motor. In this example, the piezoelectric element is divided into two regions, and the driving force is obtained by using one of the regions according to the driving direction of the moving body.

[0003] Other actuators, sensors, transformers,
In a case where a bending vibration (displacement) is generated in a buzzer, a speaker, or the like, or a signal is to be obtained by the bending vibration (displacement), the piezoelectric element is generally bonded to the elastic member as described above.

For example, in the case of a piezoelectric transformer, a predetermined performance is obtained by performing a polarization process (thickness direction and longitudinal direction) in which the direction is different in many cases, but is often constituted by the piezoelectric element itself.

[0005]

When the above method is adopted, a thin piezoelectric element must be adhered to the vibrating body, so that the workability is poor, and in some cases, the piezoelectric element may be damaged (cracked). It even happened. In addition, variations in characteristics among products due to uneven adhesive were likely to occur. Furthermore, since the movement of the piezoelectric element is transmitted to the vibrating body through the adhesive, energy loss has occurred in the adhesive. Also,
The use environment such as temperature and humidity was sometimes limited by the use of the adhesive. Further, there is a problem that high output driving is difficult due to peeling of the adhesive layer.

In the case of the above ultrasonic motor, the working part of the piezoelectric element actually used for driving is small,
There was a problem that the output was small.

In the conventional piezoelectric transformer, since the polarization direction is different, residual distortion occurs during polarization, and when used at a high output, there is a case where breakdown occurs, and electrodes are provided on the front and back surfaces and side surfaces (end surfaces) of the piezoelectric element. And the manufacturing process was complicated.

Accordingly, it is an object of the present invention to excite predetermined vibrations by using only a piezoelectric element and increase the number of actually used parts of the piezoelectric element to increase the output of actuators, sensors, transformers, and the like, and to simplify manufacturing. And

[0009]

SUMMARY OF THE INVENTION The present invention has a piezoelectric element polarized in a thickness direction, and is driven by applying an electric field between a plurality of electrodes provided on at least one surface of the piezoelectric element. An electro-mechanical conversion element characterized by obtaining force.

By providing an electrode on one surface, an electric field of the piezoelectric element can be applied on one surface.

According to the present invention, there is provided a mechanical-electrical conversion element having a piezoelectric element polarized in a thickness direction, wherein a signal is detected between a plurality of electrodes provided on at least one surface of the piezoelectric element. It is.

Since an electrode provided on one surface detects a signal, a detection signal can be extracted from one surface of the piezoelectric element.

[0013] The present invention is the electro-mechanical conversion element or the electro-mechanical conversion element, wherein the polarization directions are all the same.

The polarization can be easily performed by setting the polarization directions to the same direction.

According to the present invention, one surface of the electro-mechanical transducer has a plurality of electrodes provided at intervals of 1/2 wavelength of a vibration wave excited by the electro-mechanical transducer in a circumferential direction. The ultrasonic motor is characterized in that a moving body is driven by applying a driving signal between adjacent electrodes.

According to the present invention, there is provided an electro-mechanical conversion element comprising, on the other surface, a plurality of electrodes displaced by a quarter wavelength from the plurality of electrodes provided on the one surface in the circumferential direction. Ultrasonic motor having.

According to the present invention, one surface of the electro-mechanical transducer is provided with one-half of the vibration wave excited by the electro-mechanical transducer.
It has a plurality of electrodes provided at intervals of four wavelengths, constitutes a plurality of electrode groups in which two adjacent electrodes constitute one set, and applies a drive signal between the adjacent electrode groups to form a moving body. An ultrasonic motor characterized by being driven.

According to the present invention, in the electro-mechanical transducer, the polarization direction is reversed at an interval of a half wavelength of the vibration wave excited by the electro-mechanical transducer. Is an ultrasonic motor characterized in that a plurality of electrodes are provided at intervals of 1/4 wavelength of the vibration wave, and a moving body is driven by applying a drive signal between the adjacent electrodes.

The present invention relates to an ultrasonic motor for driving a moving body with a vibration wave excited by an electro-mechanical transducer, wherein the projection for transmitting the driving force of the vibration wave to the moving body has a base portion, An ultrasonic motor characterized in that a part of the part is guided and fixed by a guide part provided in the electro-mechanical conversion element.

The present invention has a piezoelectric element polarized in the thickness direction, and a driving signal is provided between a driving electrode provided on one surface of the piezoelectric element and a driving electrode provided on the other surface. , And an output signal is obtained from a detection electrode provided on one surface of the piezoelectric element.

The present invention is an electronic device with an ultrasonic motor, comprising an electromechanical conversion element or a electromechanical conversion element.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an energy conversion device, a driving method thereof, and an electronic device using the same according to the present invention will be described below in detail with reference to the drawings. In addition,
The present invention is not limited by the embodiment. Embodiment 1 First, a structural example of an ultrasonic motor applicable to the present invention will be described with reference to FIG. The vibrating body of the ultrasonic motor is composed of a disc-shaped piezoelectric element 1, and a through hole is made at the center of the piezoelectric element 1. The through hole is supported by a center shaft 3 having a center fixed to a support plate 4. A plurality of projecting members 2 are provided on the upper surface of the piezoelectric element.
The protruding member 2 enlarges the vibration displacement of the vibrating body including only the piezoelectric element 1 and gives the moving body 5 a rotational force. A plurality of protrusions 2a
Is composed of a base 2b joined at one end thereof and a protrusion 2c projecting from a part of the base 2b and housed in a guide surface 1a in the inner diameter of the piezoelectric element 1. These projecting members 2 are integrally formed of, for example, wear-resistant engineering plastic and are joined to the piezoelectric element 1 by bonding or the like. Here, the protrusions 2a may be directly joined to the piezoelectric element 1 individually. The piezoelectric element 1 serving as a vibrating body is fixed by a central shaft 3 via a protruding portion 2c. Here, the projecting member 2 is bonded to the piezoelectric element 1, but unlike the conventional method of bonding the piezoelectric element and the vibrating body, the bonding force here may be any value as long as a certain mechanical strength can be obtained. The protruding member 2 is bonded on the piezoelectric element 1 having a structure capable of obtaining a predetermined vibration, and does not cause imbalance in the vibration of the vibrating body and does not cause variation between products.

The moving body 5 is arranged above the piezoelectric element 1.
A through hole is made in the center of the moving body 5 and a bearing 6 is formed in the through hole.
Is fixed by fitting or bonding. The center of the bearing 6 is guided by the center shaft 3. Therefore, the moving body 5 can rotate around the central axis 3 as a rotation center. Also,
On the lower surface of the moving body 5, a friction member 5a that comes into contact with the projection member 2 of the piezoelectric element 1 is provided.

The spring member 7 is provided above the bearing 6 so as to guide the central shaft 3, and the upper portion is fixed with a screw matching a thread groove received in the center of the central shaft 3. By doing so, the inner ring of the bearing 6 can be pressurized, and the piezoelectric element 1
A suitable contact pressure can be applied between the projection 2a and the friction member 5a of the moving body 5. Therefore, the electric energy applied to the piezoelectric element 1 becomes a vibration wave excited by the vibrating body by the piezoelectric effect of the piezoelectric element 1. This vibration wave
The frictional force generated between the projection 2a and the friction member 5a of the moving body 5 becomes the rotational force of the moving body 5 and is converted into mechanical energy.

Next, the operating principle of the ultrasonic motor according to the first embodiment will be described with reference to FIGS. FIG.
Shows the electrode configuration of the piezoelectric element in this embodiment. 2A shows a first surface of the piezoelectric element 1, and FIG. 2B shows a second surface. Here, the first surface and the second surface have a front-back relationship.

On the first surface of the piezoelectric element 1, the electrodes 8a, 8a
b is arranged. The electrodes 8 a and 8 b are equally divided in the circumferential direction of the piezoelectric element 1 at a half wavelength interval of the vibration wave excited by the piezoelectric element 1. A certain interval is provided between the electrodes 8a and 8b so as not to contact each other.

The electrodes 9a and 9b are also provided on the second surface of the piezoelectric element 1 as in the first surface.

At this time, the electrodes 8a, 8 provided on the first surface
b and the electrodes 9a and 9b provided on the second surface have a half pitch (1/1 /) in the circumferential direction when viewed from the first surface or the second surface.
(4 wavelengths).

FIG. 3 shows the driving principle in this embodiment. The piezoelectric element 1 has an arrow P in the thickness direction.
Is polarized in one direction. The protrusion 2a is joined to the second surface side at equal intervals at a position shifted by 1/8 wavelength from a node of the standing wave excited by the electrodes 8a, 8b, 9a and 9b. When a drive signal is applied between the electrodes 8a and 8b on the first surface, an electric field is applied from the electrode 8b toward the electrode 8a as shown by an arrow 100 at a certain moment. With this electric field,
In the vicinity of the electrodes 8a and 8b with respect to the thickness direction of the piezoelectric element 1, that is, near the surface, the direction of the electric field acts in the thickness direction, and the piezoelectric element 1 expands and contracts according to the relationship between the direction of the electric field and the direction of polarization. Further, in the vicinity of the boundary between the electrode 8a and the electrode 8b, in particular, at a portion penetrating from the surface, the electric field acts in a direction perpendicular to the polarization direction P, so that sliding vibration also occurs. However,
The strength of the electric field is determined on the first surface of the piezoelectric element 1 (electrodes 8a and 8b).
Since only the first side is strong, the displacement associated therewith occurs only on the first surface side. Therefore, a bent standing wave is generated in which a portion bent upward from the stationary position and a portion bent downward from the stationary position as shown in FIG. 3B appear. At this time, since the protrusion 2a is located on the right side with respect to the vertex of the bending standing wave, the raised protrusion 2a is inclined to the right. On the other hand, the lowered projection 2a is inclined leftward. The protrusion 2a is in contact with the moving body 5 according to FIG.
The moving body 5 (not shown) moves or rotates from left to right in the figure.

FIG. 3C shows a case where a drive signal is applied between the electrodes 9a and 9b provided on the second surface. When an electric field is applied from the electrode 9b toward the electrode 9a, a bent standing wave is generated in which a portion bent upward from the stationary position and a portion bent downward from the stationary position appear. At this time, since the protrusion 2a is located on the left side with respect to the vertex of the bending standing wave, the raised protrusion 2a tilts to the left, while the lowered protrusion 2a tilts to the right. Therefore, the moving body 5 moves or rotates from right to left in the figure.

Thus, the moving direction of the moving body 5 can be changed depending on which of the electrodes 8a and 8b on the first surface and the electrodes 9a and 9b on the second surface the signal is applied. Although an example using a standing wave has been described above, a traveling wave may be generated in the piezoelectric element 1 serving as a vibrator. At this time, the phase of the signal applied between the electrodes 8a and 8b and the phase of the signal applied between the electrodes 9a and 9b may be changed, for example, by 90 degrees. Further, in this embodiment, the vibrating body is constituted only by the piezoelectric element 1, but it is needless to say that the vibrating body may be constituted by joining with another elastic member.

As described above, in the present embodiment, the bending vibration is generated only by the piezoelectric element 1 without bonding to the elastic member, and the polarization direction is the same.
Productivity can be improved. Further, by polarizing in the same direction, there is no boundary portion where the polarization direction is reversed, and the breaking strength is increased. In addition, by applying a drive signal to all the electrodes provided on one surface of the piezoelectric element 1 and driving the same, the expansion and contraction vibration of the piezoelectric element 1 due to the piezoelectric transverse effect,
In addition, since thickness-shear vibration having a high electro-mechanical coupling coefficient is used, it is possible to obtain a high-output and highly reliable ultrasonic motor. Furthermore, since a drive signal only needs to be applied to the entire electrode provided on one surface, a conductive structure for applying a signal to the piezoelectric element, that is, a lead extraction structure is simplified.

As described above, the piezoelectric element 1 of the present embodiment converts electric energy into mechanical energy.
Works as a mechanical conversion element. Embodiment 2 FIG. 4 shows Embodiment 2 of the present invention.
This will be described with reference to FIG. Hereinafter, the mechanism for generating the driving force and the effect thereof are almost the same as those described in the first embodiment, and therefore, only the parts such as the configuration that are different from the first embodiment will be described.

The piezoelectric element 1 is polarized in one direction in the direction of the arrow P with respect to the thickness direction. On the lower surface of the piezoelectric element 1, electrodes 8 c, 8 d equally divided at quarter wavelength intervals of the vibration wave excited by the piezoelectric element 1 in the circumferential direction of the piezoelectric element 1.
8e and 8f are provided. The electrodes 8c, 8d, 8e, 8
f may be provided on the upper surface of the piezoelectric element 1. The projection 2a is joined to a portion corresponding to the center of each of the electrodes 8d and 8f. Electrode 8
When a drive signal is applied between c and 8d and the electrodes 8e and 8f, a standing wave shown in FIG. 4B is generated. At this time, since the protrusion 2a is located on the right side with respect to the vertex of the bending standing wave, the raised protrusion 2a tilts to the right, and the moving body 5 moves or rotates from left to right in the figure.

When a drive signal is applied between the electrodes 8d and 8e and the electrodes 8c and 8f, a standing wave as shown in FIG. 4C is generated. At this time, since the protrusion 2a is located on the left side with respect to the vertex of the bending standing wave, the raised protrusion 2a tilts to the left, and the moving body 5 moves or rotates from right to left in the drawing.

Thus, the moving direction of the moving body 5 can be changed by selecting a combination of the electrodes with respect to the driving signal.

As described above, the piezoelectric element 1 of the present embodiment converts electric energy into mechanical energy.
Works as a mechanical conversion element. Embodiment 3 Embodiment 3 of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The piezoelectric element 1 is polarized in the direction of arrow P with respect to the thickness direction. At this time, the direction is symmetrical at every half wavelength of the vibration wave excited by the piezoelectric element 1. For example, when a certain portion is polarized from the lower surface toward the upper surface, a portion separated from the portion by 振動 wavelength of the vibration wave is polarized from the upper surface toward the lower surface. Piezoelectric element 1
On the lower surface of the piezoelectric element 1 in the circumferential direction of the piezoelectric element 1.
8 divided at quarter wavelength intervals of the vibration wave excited by
g and 8h are provided. Therefore, the polarization direction is electrode 8h,
Invert at half wavelength interval at the boundary between 8g.

For example, the projection 2a is joined to the center of the electrode 8h. When a drive signal is applied between the electrode 8g and the electrode 8h, a standing wave as shown in FIG. 5B is generated. At this time, since the protrusion 2a is located on the left side with respect to the vertex of the bending standing wave, the raised protrusion 2a tilts to the left, and the moving body 5 moves or rotates from right to left in the drawing.

Here, the length of the electrodes 8g and 8h is 1 /
It is short for four wavelengths, the electric field exerted by the drive signal on the piezoelectric element 1 is large, and it is possible to drive with low voltage and high output.

As described above, the piezoelectric element 1 of the present embodiment converts electric energy into mechanical energy.
Works as a mechanical conversion element. Embodiment 4 Embodiment 4 of the present invention is shown in FIG.
This will be described with reference to FIG. Embodiment 4 relates to an electro-mechanical conversion element including the piezoelectric element 1 of the present invention, a piezoelectric transformer using the mechanical-electric conversion element, and an electronic apparatus using the piezoelectric transformer.

In FIG. 6A, a rectangular plate-shaped piezoelectric element 1 is shown.
Are provided with electrodes 8i, 8j on the half surface from the center to one end of both surfaces. Electrodes 8k and 8l are provided on one side of the piezoelectric element 1 from the center where the electrode 8i is not provided to the other end. In the figure, the arrow P indicates the polarization direction, and the polarization direction is reversed with the dotted line interposed. When a drive signal is applied to the electrodes 8i and 8j by the drive circuit 10, a displacement distribution shown by a curve 21 in FIG. 6B is obtained. The piezoelectric element 1 expands and contracts in the longitudinal direction with the longitudinal center as a node. At this time, a voltage higher than the input voltage is output from the electrodes 8k and 8l to drive the driving target 11. The drive target 11 corresponds to, for example, a backlight of a liquid crystal display and a circuit for driving the backlight, and is mounted inside, for example, a personal computer (not shown).

Here, since all the polarization treatments are performed in the thickness direction, the voltage required for the polarization can be reduced, the restriction on the production equipment and the like is less likely to occur, and the production becomes easier. The electrodes 8m and 8n are electrodes used for polarization, and
j. In some cases, the voltages 8m and 8n after polarization may be removed. Furthermore, since the polarization direction is constant even near the center where the stress is maximum, it is resistant to destruction even when used at high output. Further, since the size and position of the electrodes 8k and 8l and the gap between them can be freely set, the driving object 1 serving as a load can be set.
The output impedance can be adjusted to match the impedance of 1 and an arbitrary boost ratio can be set. Also, since the polarization direction is only the thickness direction,
The electrodes may be provided only on the front and back surfaces of the piezoelectric element 1, and the stacking of the piezoelectric element 1 can be easily realized. By doing so,
Various characteristic parameters such as input impedance, output impedance, and step-up ratio can be freely set, and the degree of freedom in design can be expanded. Embodiment 5 FIG. 7 shows an example of another embodiment. In the fifth embodiment, description of portions common to those described in the fourth embodiment will be omitted, and only different points will be described. As shown by the curve 22 in FIG. 7A, the rectangular plate-shaped piezoelectric element 1 is provided with electrodes 8i and 8j on the half surface from the center to one end of both the front and back surfaces. In addition, electrodes 8k and 8l are provided on one surface of the piezoelectric element 1 from the center where the electrode 8i is not provided to the other end.
The arrow P in the figure indicates the polarization direction, and the entire piezoelectric element 1 is polarized in one direction in the thickness direction. Drive circuit 10
When drive signals are applied to the electrodes 8i and 8j by the
The piezoelectric element 1 vibrates in the longitudinal direction with two nodes in the longitudinal direction as nodes, as shown in the displacement distribution shown in FIG. At this time, the electrode 8
k, 8 output a voltage higher than the input voltage,
The driving object 11 is driven. The drive target 11 corresponds to, for example, a backlight of a liquid crystal display and a circuit for driving the backlight, and is mounted inside a personal computer (not shown), for example.

Here, since all the polarization treatments are performed in the thickness direction, the voltage required for the polarization can be low, and the production equipment and the like are less likely to be restricted, and the production is facilitated. Furthermore, since the polarization direction is uniform and has no boundaries, it is strong against destruction, and high output driving is possible.

The G of the driving circuit 10 and the driving object 11
A common electrode may be provided on the piezoelectric element 1 so that the ND is common. Further, the modification of the present embodiment is optional. For example, the drive electrodes 8i, 8j and the detection electrodes 8k, 8l are provided on the left and right with the center of the piezoelectric element 1 as a boundary, but the drive electrodes 8i, 8j May be provided at a position including the central portion of the piezoelectric element 1, and the detection electrodes 8k and 8l may be provided at other portions.

As described above, the piezoelectric element 1 of the present embodiment
Has both an electro-mechanical conversion element that converts electrical energy into mechanical energy and a mechanical-electric conversion element that converts mechanical energy into electrical energy.
Therefore, a sensor for measuring acceleration and pressure can be easily realized by using the electromechanical transducer in the present embodiment. Embodiment 6 FIG. 8 shows a block diagram of Embodiment 5 in which an ultrasonic motor using an electro-mechanical transducer according to the present invention is applied to an electronic device.

The electronic apparatus comprises a vibrating body composed of the above-described piezoelectric element 1, a moving body 5 driven by the vibrating body, and a moving body 5
And a transmission mechanism 12 that moves in conjunction with the moving body 5, and an output mechanism 13 that moves based on the operation of the transmission mechanism 12.

Here, as the transmission mechanism 12, for example, a transmission wheel such as a gear wheel or a friction wheel is used, and this is formed directly on the moving body 5. The transmission mechanism 12 may be omitted and the direct output mechanism 13 may be provided. For example, in the case of a pointing device or an electronic timepiece, the output mechanism 12 includes a pointer, a pointer driving mechanism, a display plate such as a calendar, or a display plate driving mechanism as shown in FIG. For cameras and video cameras, shutters, aperture drives, lens drives, film winding mechanisms, etc. are used for measuring instruments and manufacturing equipment that use lasers and light. A slit plate or a filter that transmits only light of a specific wavelength is used, a contact mechanism or a gap plate that changes a resistance value or a capacitance value is used for a volume of an audio device, and a pickup driving mechanism is used for a hard disk or an optical disk.

If the output shaft is attached to the movable body 5 and a power transmission mechanism for transmitting torque from the output shaft is provided, the driving mechanism can be realized by the ultrasonic motor itself.

By applying the ultrasonic motor of the present invention to an electronic device, lower voltage, lower power consumption, smaller size, and lower cost of the electronic device can be realized. The use of an ultrasonic motor naturally has the characteristics that it is not affected by magnetism and no harmful magnetic noise is generated.

[0050]

As described above, according to the present invention, an actuator is obtained such that a driving force is obtained by applying an electric field between a plurality of electrodes provided on at least one surface of a piezoelectric element polarized in a thickness direction. Constitute. According to this, since the bending vibration can be generated by the piezoelectric element alone, it is not necessary to bond to another elastic member, and the product is excellent in reliability and less in variation between products, so that an inexpensive product can be obtained. Furthermore, since no adhesive is used, the mechanical strength is increased and, in addition, the output is increased because the drive signal is applied to all the electrodes provided on one surface of the piezoelectric element.

In the case of a sensor or a transformer, the same configuration is adopted. In this case, a signal is detected from between electrodes (in the case of a transformer, there is a case where an input is made), so that it is small and large (in the case of a transformer, a booster is used). (High ratio) signal.

Further, according to the present invention, an electronic device having the above-described electro-mechanical conversion element or the electro-mechanical conversion element can be realized, and the electronic device can be reduced in size and power consumption.

[Brief description of the drawings]

FIG. 1 shows an example of the structure of an ultrasonic motor according to the present invention.

FIG. 2 shows an electrode pattern of a piezoelectric element of the ultrasonic motor according to the present invention.

FIG. 3 shows a first example of a driving principle of an ultrasonic motor according to the present invention.

FIG. 4 shows a second example of the driving principle of the ultrasonic motor according to the present invention.

FIG. 5 shows a third example of the driving principle of the ultrasonic motor according to the present invention.

FIG. 6 shows an example of the structure and operation principle of the piezoelectric transformer of the present invention.

FIG. 7 shows another example of the structure and operation principle of the piezoelectric transformer of the present invention.

FIG. 8 is a block diagram showing an electronic apparatus using the ultrasonic motor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Projection member 3 Center axis 4 Support plate 5 Moving body 6 Bearing 7 Pressing mechanism 8, 9 Electrode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04R 17/02 G01S 7/52 A // H02M 3/24 H01L 41/08 U A (72) Inventor Kosaka Takayuki 1-8 Nakase, Mihama-ku, Chiba-shi F-term (reference) in Seiko Instruments Inc. DD85 DD92 DD95 EE03 EE10 EE12 EE24 FF05 FF08 FF32 5H730 AA15 ZZ19 5J083 CB01 CB07 CB14 CB19

Claims (10)

[Claims] A piezoelectric element polarized in a thickness direction;
An electro-mechanical conversion element, wherein a driving force is obtained by applying an electric field between a plurality of electrodes provided in at least one surface of the piezoelectric element. 2. It has a piezoelectric element polarized in a thickness direction,
A mechanical-electrical conversion element for detecting a signal between a plurality of electrodes provided on at least one surface of the piezoelectric element. 3. The electro-mechanical conversion element or the electro-mechanical conversion element according to claim 1, wherein the polarization directions are all the same. 4. A plurality of electro-mechanical conversion elements according to claim 3, provided on one surface thereof at intervals of one-half wavelength of a vibration wave excited by the electro-mechanical conversion elements in a circumferential direction. An ultrasonic motor having electrodes and driving a moving body by applying a driving signal between adjacent electrodes. 5. On the other surface of the electro-mechanical conversion element, there are provided a plurality of electrodes whose positions are shifted by / wavelength from the plurality of electrodes provided on the one surface in the circumferential direction. The ultrasonic motor according to claim 4, wherein: 6. An electro-mechanical conversion device according to claim 3, wherein one surface of the electro-mechanical conversion device has a plurality of electrodes provided at intervals of 波長 wavelength of a vibration wave excited by the electro-mechanical conversion device. Configure a plurality of electrode groups with a pair of two adjacent electrodes,
An ultrasonic motor for driving a moving body by applying a driving signal between adjacent electrode groups. 7. The electro-mechanical conversion element according to claim 1, wherein the polarization direction is inverted at an interval of a half wavelength of a vibration wave excited by the electro-mechanical conversion element, and one of the electro-mechanical conversion elements is provided. A plurality of electrodes are provided on the surface at intervals of 1/4 wavelength of the vibration wave, and the moving body is driven by applying a drive signal between the adjacent electrodes. 8. An ultrasonic motor for driving a moving body with a vibration wave excited by an electro-mechanical transducer, wherein the projection for transmitting the driving force of the vibration wave to the moving body has a base, and An ultrasonic motor, wherein a part is guided and fixed by a guide portion provided on the electro-mechanical conversion element. 9. It has a piezoelectric element polarized in the thickness direction,
A driving electrode provided on one surface of the piezoelectric element and a drive signal input between the driving electrodes provided on the other surface, and a detection electrode provided on one surface of the piezoelectric element. A piezoelectric transformer characterized by obtaining an output signal. 10. An electronic device with an ultrasonic motor, comprising the electro-mechanical conversion device or the electro-mechanical conversion device according to claim 1.