JPH1028386A - Ultrasonic motor and method for controlling it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and cost of a rotation-detecting element, without deteriorating the detecting accuracy and characteristics of the element by providing the element on an elastic body which is elastically brought into contact with the projecting part of irregularities, provided in the rotational direction of either a vibrating body or vibrated body. SOLUTION: When AC voltages, having a 90 deg. phase difference between them, are respectively applied across two driving electrodes formed on a first piezoelectric body 2, primary or higher and tertiary or high elastic progressive waves are respectively excited in a vibrating body 3 in the radial and peripheral directions and a moving body 5 which is press-contacted with a projecting body 4 is frictionally driven by the wave fronts of the elastic progressive waves and makes revolving motions. The second piezoelectric body 14 of a rotation-detecting element 15 which is brought into contact with the irregularities of the moving body 15 generates induced charges, corresponding to the irregularities 12 due to the elastic deformation of a second elastic body 13 which is caused by the rotation of the moving body 5 and controls the rotating speed and rotational angle of the moving body 5, by using pulse signals obtained from the induced charges. Therefore, the information on the stoppage of rotation and the accuracy of rotating speed for the moving body 5 can be improved. In addition, the counting accuracy can also be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor that generates a driving force by using elastic vibrations excited by a piezoelectric effect of a piezoelectric body, and a control method thereof.

[0002]

2. Description of the Related Art In recent years, an ultrasonic motor that uses a piezoelectric body such as a piezoelectric ceramic having a piezoelectric effect to excite elastic vibrations in a vibrating body and uses this as a driving force has attracted attention. FIG.
FIG. 1 shows an example of the structure of a conventional ultrasonic motor disclosed in JP-A-63-287376. This figure shows a partial cross-sectional side view. In the figure, 32 is a moving body, 33 is a vibrating body having an electrostrictive element, 34a is a vibrating body 3
A number of vibrating reeds 34 b are provided on the vibrating reed 34.
The groove 35 formed between a is a light emitting diode phototransistor fixed to the moving body 32 as a position detecting device.

FIG. 35 is a diagram showing an example of a drive electrode structure of an electrostrictive element used in a ring-shaped ultrasonic motor. FIG. 1 shows an electrode structure in which six elastic waves are excited in the circumferential direction. A and B are electrode groups each composed of a small region corresponding to a half wavelength, C is an electrode corresponding to three quarter wavelengths, and D is an electrode corresponding to a quarter wavelength. The electrodes C and D position the electrode groups A and B in position by a quarter wavelength (= 90 degrees).
Is provided to cause a phase difference of The adjacent small electrode portions (a1 to a5, b1 to b5) in the electrodes A and B are polarized in the thickness direction opposite to each other. The bonding surface of the electrostrictive element with the elastic body is a surface opposite to the surface shown in FIG.
The electrodes are solid electrodes. During driving, the electrode groups A and B
Are short-circuited, as indicated by hatching in FIG.

The operation of the conventional ultrasonic motor configured as described above will be described below. First, voltages V1 and V2 expressed by the equations (1) and (2) are applied to the electrodes A and B of the electrostrictive element of the ultrasonic motor, respectively. V1 = V0 × sin (ωt) --- (1) V2 = V0 × cos (ωt) --- (2) where V0 is the instantaneous value of voltage, ω is angular frequency, and t is time.

As a result, a traveling wave of a bending vibration traveling in the circumferential direction expressed by the equation (3) is excited in the vibrator. ξ = ξ0 × ｛cos (ωt) × cos (kx) + sin (ωt) × sin (kx)｝ = ξ0 × cos (ωt-kx) --- (3) where ξ is the amplitude value of the bending vibration, ξ0 is the instantaneous value of the bending vibration, k is the wave number (2π / λ), λ is the wavelength, and x is the position.

Further, as shown in FIG. 5 for describing the invention described below, point A on the surface of the vibrating body indicates an elliptic motion of a vertical axis 2w and a horizontal axis 2u obtained by exciting a traveling wave, and is applied to the vibrating body. The moving body placed under pressure comes into contact near the apex of the elliptical motion, and in the direction opposite to the traveling direction of the wave due to frictional force (4)
Move at the speed v in the equation. v = ω × u --- (4) At this time, the position of the moving body 32 is detected by the vibrating piece 34 a relatively passing between the light emitting diode and the phototransistor 35 provided on the moving body 32. This is performed by an on / off signal.

As another method of detecting the number of revolutions of a conventional ultrasonic motor other than the above, as disclosed in Japanese Patent Application Laid-Open No. 01-85585, a mechanical arm current input to a piezoelectric body is used to detect the vibration of a vibrating body. A method of controlling the rotation speed by estimating the amplitude, a rotary encoder attached to a rotating shaft as disclosed in JP-A-03-117383, or a magnetic encoder as disclosed in JP-A-63-217980 Rotation detection configuration using a resistance element
As disclosed in Japanese Unexamined Patent Application Publication No. 2002-209, a method of directly forming a diffraction grating on a moving body and optically detecting rotation is disclosed.

[0008]

However, in the conventional ultrasonic motor using the rotation detection method based on the mechanical arm current, the rotation speed of the moving body is not directly detected.
There are problems that the detection accuracy is poor and it is difficult to control the low-speed rotation, and that detection is not possible even if the rotation of the moving body stops.

Also, an ultrasonic motor using a rotation detection method using an optical rotary encoder or the like has a problem that the device becomes large and power consumption increases due to a light emitting element, and further, the encoder itself becomes a load torque. ,
Deterioration of characteristics, low cost, and miniaturization of equipment,
This is a particularly big problem. Ultrasonic motors that use a rotation detection method based on a magnetoresistive element are expensive, are very difficult to use in a magnetic field, and are nonmagnetic. There is a problem that it cannot be utilized.

It is therefore an object of the present invention to provide an ultrasonic motor which solves the above-mentioned problems, has a high detection accuracy, does not deteriorate the characteristics, can reduce the size of the apparatus, and can reduce the cost.

[0011]

According to a first aspect of the present invention, there is provided an ultrasonic motor, comprising: a vibrating body having a first piezoelectric body and vibrating by inputting an electric signal; and a vibrating body coming into contact with the vibrating body. And an uneven body provided in one rotation direction of the vibrating body and the vibrated body, and an elastic body elastically deformed by rotation of the vibrating body or the vibrated body by elastically contacting the convex surface of the unevenness. A rotation detecting element provided with a second piezoelectric body that induces electric charge by elastic deformation of the elastic body, wherein one of the vibrating body and the vibrated body is rotated by the vibration of the vibrating body.

According to the ultrasonic motor of the first aspect, when an electric signal is input to the first piezoelectric body and the vibrating body vibrates,
The vibrated body or the vibrating body moves. As a result, the irregularities move, so that the second elastic body of the rotation detecting element vibrates,
When the piezoelectric body is deformed and distorted, electric charges are induced.
Therefore, the rotation speed and the rotation angle can be controlled by detecting and measuring this charge. As a result, the detection accuracy is higher than before, the characteristics are not reduced, the device can be downsized, and the cost can be reduced without the need to provide a detection device more expensive than the ultrasonic motor.

The ultrasonic motor according to the second aspect is the first aspect of the invention.
In the above, the unevenness is formed on the peripheral surface of the rotating shaft. According to the ultrasonic motor described in claim 2, claim 1 is provided.
In addition to the above-mentioned effects, the unevenness is formed on the rotating shaft with a small radius of rotation. Without deteriorating the characteristics.
The rotation speed and rotation angle can be controlled.

The ultrasonic motor according to the third aspect is the first aspect of the invention.
In the above, the rotating member of the vibrating body and the vibrated body has a rotation axis, and the non-rotating body of the vibrating body and the vibrated body has a supporting member that is inserted into the rotating shaft and has a convex shape portion at one end in the axial direction. The convex portion is slidably supported by the concave portion of the support means. According to the ultrasonic motor of the third aspect, in addition to the effect of the first aspect, the convex member slides in the concave portion so that the support member can rotate with respect to the support means and the vibrating member or the vibrating member can be pivoted. Since it can be tilted with respect to the direction, the contact state between the protrusion and the vibrating body that comes into contact with the protruding body against external load such as lateral pressure applied to the vibrating body or the vibrated body can be uniform, and Since an elastic member interposed between the fixed side of the body and the support means is not required, it is not necessary to consider a temporal change of the elastic member due to long-term use.

According to a fourth aspect of the present invention, there is provided a method for controlling an ultrasonic motor according to the first, second or third aspect of the present invention, wherein the electric charge induced in the second piezoelectric body is reduced. This is converted into an electric signal, the electric signal is counted for a unit time, and control is performed so that the count value of the unit time is equal to the command value of the speed or the rotation angle. Claim 4
According to the control method of the ultrasonic motor described above, stable rotation can be obtained with high accuracy.

An ultrasonic motor according to a fifth aspect of the present invention is the ultrasonic motor according to the first, second or third aspect, wherein the interval between adjacent projections is uneven. According to the ultrasonic motor of the fifth aspect, in addition to the effects of the first, second, and third aspects, the rotational speed can be detected and controlled without being restricted by the accuracy of forming the unevenness, thereby improving the productivity. Can be expected. In addition, control can be performed based on the time required for one rotation of the vibrating body, the vibrated body, or the rotating shaft, and the rotation can be detected with high accuracy.

According to a sixth aspect of the present invention, in the ultrasonic motor according to the first, second, or third aspect, the interval between adjacent projections of the unevenness monotonically increases within one rotation of the vibrating body or the vibrating body. It decreases monotonically. According to the ultrasonic motor of the sixth aspect, in addition to the effects of the first, second, and third aspects, it is possible to detect the rotation direction of the vibrating body or the vibrated body.

According to a seventh aspect of the present invention, there is provided a method of controlling an ultrasonic motor according to the first, second, third, fifth, or sixth aspect. The electric charge induced in the piezoelectric body is converted into an electric signal, and the time required for one rotation is measured based on the number of electric signals per rotation of the vibrating or vibrating body. Control is performed so that the values become equal.

According to the control method of the ultrasonic motor according to the seventh aspect, the same effect as the fourth aspect is obtained. An ultrasonic motor control method according to claim 8 is a method for controlling an ultrasonic motor according to claim 6, wherein the ultrasonic motor has at least N (N> 4) projections and depressions. To convert the electric charge induced in the second piezoelectric body of the rotation detecting element into an electric signal,
The time intervals of at least four or more N-1 consecutive electrical signals are sequentially compared, and the rotation direction of the vibrating body or the vibrated body is detected by detecting the number of times of increase or decrease of at least two or more N-2. , For controlling the rotation direction.

According to the control method of the ultrasonic motor according to the present invention, a simple configuration can be achieved without adding another sensor.
An ultrasonic motor capable of detecting and controlling a moving direction such as a rotating direction of a vibrating body or a vibrated body can be realized. According to a ninth aspect of the present invention, in the ultrasonic motor according to any one of the first, second, third, fifth, and sixth aspects, the contact portion that contacts the unevenness of the second elastic body has a convex portion or a curved portion. It has.

According to the ultrasonic motor of the ninth aspect, the first, second, third, fifth or sixth aspect of the present invention is applicable.
In addition to the effects described above, it is possible to prevent the second elastic body from being caught by the irregularities, and to reduce the rotational resistance due to the contact of the irregularities in the rotation direction. The ultrasonic motor according to claim 10 is
In claim 1, claim 2, claim 3, claim 5, claim 6, or claim 9, the gear-shaped uneven member having unevenness is fitted to a rotating body or a rotating shaft of the vibrating body or the vibrated body. It is what I wore.

According to the ultrasonic motor of the tenth aspect,
It has the same effect as claim 1, claim 2, claim 3, claim 5, claim 6, or claim 9. An ultrasonic motor according to claim 11, wherein the vibrating body has a piezoelectric body and vibrates by inputting an electric signal, a vibrating body that contacts the vibrating body, and one of the vibrating body and the vibrating body. Equipped with unevenness formed by slits arranged in the direction, and a rotation detecting element having a counter electrode opposed to the unevenness at both ends of the slit, and one of the vibrating body and the vibrated body is caused by the vibration of the vibrating body. It rotates.

According to the ultrasonic motor of the eleventh aspect,
Since the opposing electrode of the rotation detecting element opposes the unevenness in a non-contact manner, uniform contact between the protruding body and the vibrated body can be realized without the influence of a decrease in driving torque or side pressure. According to a twelfth aspect of the present invention, in the ultrasonic motor according to the eleventh aspect, the vibrating body and the vibrating body have a rotating shaft, and the non-rotating vibrating body and the vibrating body are inserted through the rotating shaft. A support member having a convex shape portion is provided at one end in the axial direction, and the convex shape portion is slidably supported by a concave portion of the support means.

According to the ultrasonic motor of the twelfth aspect,
In addition to the effect of claim 11, there is the same effect as claim 3. 14. The ultrasonic motor according to claim 13, wherein the vibrating body includes a piezoelectric body and vibrates by inputting an electric signal, a vibrating body that contacts the vibrating body, and one surface of the vibrating body and the vibrating body. And a conductive film in which portions without conductors are arranged in a row in the direction of rotation, and a conductive film is formed such that a portion where a conductor does not exist and a portion where a conductor exists alternately pass by rotation of a vibrating body or a vibrating body. A rotation detecting element having a counter electrode facing the film in a non-contact manner, wherein the vibrating body or the vibrating body on which the conductive film is formed is formed of a high-resistance material, and the vibrating body or the vibrating body is formed by the vibration of the vibrating body. Is one that rotates.

According to the ultrasonic motor of the thirteenth aspect,
In addition to having the effect of claim 11, the distance between the counter electrode and the conductive film can be made as small as possible, so that the detection capacitance that increases in proportion to the distance can be increased and the facing area can be increased, so that the capacitance can be further increased. , Detection accuracy can be improved. An ultrasonic motor according to a fourteenth aspect is the first aspect.
In 3, the rotating member of the vibrating body and the vibrated member has a rotating shaft, and the non-rotating member of the vibrating member and the vibrating member has a supporting member that is inserted through the rotating shaft and has a convex shape portion at one end in the axial direction. And the convex-shaped portion is slidably supported by the concave portion of the supporting means.

According to the ultrasonic motor of claim 14,
In addition to the effect of claim 13, the same effect as in claim 3 is obtained. An ultrasonic motor according to a fifteenth aspect of the present invention is the ultrasonic motor according to the eleventh or twelfth aspect, wherein the unevenness forming the slit is formed on a side surface of the vibrating body or the vibrating body, and a conductive film is formed on the convex surface. The existing portions are connected to each other, and provided so that a counter electrode of the rotation detecting element faces the convex surface.

According to the ultrasonic motor of claim 15,
This has the same effect as the eleventh or twelfth aspect. Claim 1
An ultrasonic motor according to claim 6, wherein the counter electrode of the rotation detecting element is provided so as to oppose the diametrical direction of the vibrating body or the vibrating body having irregularities in claim 11, 12 or 15. It is.

According to the ultrasonic motor of the sixteenth aspect,
The same effect as that of claim 11, 12, or 15 is obtained. An ultrasonic motor control method according to a seventeenth aspect is the ultrasonic motor control method according to the eleventh aspect, the twelfth aspect, the thirteenth aspect, or the fourteenth aspect, wherein the method corresponds to rotation of a vibrating body or a vibrated body. Then, the capacitance change induced in the rotation detecting element is converted into an electric signal, and the electric signal is counted for a unit time.
The present invention is characterized in that control is performed so that the count value per unit time is equal to a command value of a speed and a rotation angle.

According to the ultrasonic motor control method of the seventeenth aspect, the same effect as that of the fourth aspect is obtained. An ultrasonic motor according to an eighteenth aspect is the ultrasonic motor according to the eleventh aspect, the twelfth aspect, or the thirteenth aspect, wherein the interval between the uneven slits is made non-uniform. According to the ultrasonic motor of the eighteenth aspect, the same effect as that of the fifth aspect is obtained.

An ultrasonic motor according to a nineteenth aspect of the present invention is the ultrasonic motor according to the eleventh, twelfth, or thirteenth aspect, wherein an interval between adjacent slits of the unevenness monotonically increases or decreases within one rotation. It is. According to the ultrasonic motor of the nineteenth aspect, the same effect as the sixth aspect is obtained. The control method of the ultrasonic motor according to claim 20 is the method according to claim 11,
A control method of an ultrasonic motor according to claim 12, claim 13, claim 14, claim 18, or claim 19,
The capacitance change induced in the rotation detecting element is converted into an electric signal corresponding to the rotation of the vibrating body or the vibrated body, and the time required for one rotation is calculated from the number of electric signals per one rotation of the vibrating body or the vibrated body. It is characterized in that measurement is performed and control is performed so that the time per one rotation becomes equal to the command value of the speed and the rotation angle.

According to the ultrasonic motor control method of the twentieth aspect, the same effect as the seventh aspect is obtained. The control method of an ultrasonic motor according to the present invention has a portion in which at least N (N> 4) or more conductive film conductors exist.
The method of controlling an ultrasonic motor according to claim 1, wherein a change in capacitance induced in the rotation detecting element in response to the rotation is converted into an electric signal, and a time interval between at least four or more N-1 consecutive electric signals is calculated. The rotational direction of the vibrating body or the vibrated body is detected by detecting the number of times of increase or decrease of at least N−2 by sequentially comparing, and controlling the rotational direction.

According to the ultrasonic motor control method of the twenty-first aspect, the same effect as that of the eighth aspect is obtained. An ultrasonic motor according to a twenty-second aspect is the ultrasonic motor according to the first, second, or eleventh aspect.
In, the vibrating body is supported by supporting means via an elastic member, the supporting means is pressed by the vibrating body by the pressing means, thereby fixing the vibrating body by the frictional force of the elastic member,
The elastic member is an elastic body made of an insulating material including an air layer.

According to the ultrasonic motor described in claim 22,
The effects of claim 1, claim 2 or claim 11 are obtained. The ultrasonic motor according to claim 23, according to claim 22,
The elastic member is made of a felt material. Claim 23
According to the ultrasonic motor described above, the effect of claim 22 is obtained.

The ultrasonic motor according to claim 24 is the ultrasonic motor according to claim 1, claim 2, claim 3, claim 11, claim 12, claim 13, or claim 14, wherein The thickness on the side is not uniform. According to the ultrasonic motor of claim 24, in addition to the effects of claim 1, claim 2, claim 3, claim 11, claim 12, claim 13 or claim 14, the inner peripheral portion of the elastic body By reducing the bending stiffness of the vibrator, the resonance resistance of the vibrator can be reduced, and the amount of vibration displacement can be expanded for the same input power as a uniform vibrator that does not have an uneven thickness of the elastic body. realizable.

According to a twenty-fifth aspect of the present invention, in the ultrasonic motor according to the eleventh or twelfth aspect, a gear-shaped uneven member having unevenness is fitted to a vibrating member or a rotating member of a vibrating member. According to the ultrasonic motor of the twenty-fifth aspect, the same effect as the tenth aspect is obtained. An ultrasonic motor according to claim 26 is the ultrasonic motor according to claim 11 or 12, wherein the concave portion of the unevenness provided on the vibrating body or the vibrating body is filled with a substance having a relative permittivity different from that of the vibrating body or the vibrating body. is there.

According to the ultrasonic motor of claim 26,
This has the same effect as the eleventh or twelfth aspect. Claim 2
An ultrasonic motor according to a seventh aspect of the present invention is the ultrasonic motor according to the third, twelfth, or fourteenth aspect, wherein the concave portion of the support means has a conical shape, and the convex shape portion fitted to the concave portion has a spherical shape.

According to the ultrasonic motor of claim 27,
The same effects as those of the third, twelfth and fourteenth aspects are obtained. The ultrasonic motor according to claim 28 is the third or twelfth aspect.
Alternatively, the concave portion of the supporting means has a spheroidal shape, and the convex-shaped portion fitted to the concave portion has a spheroidal shape.

According to the ultrasonic motor of the twenty-eighth aspect,
In addition to the effects of the third, twelfth, and fourteenth aspects, a rotational reaction force of the vibrating body or the vibrated body can be easily prevented. In the ultrasonic motor according to claim 29, in claim 1, claim 2, claim 3, claim 11, claim 12, claim 13, or claim 14, the elastic body is excited by the first piezoelectric body. The velocity distribution, which is the time derivative of the radial vibration displacement distribution, and the radial direction generated as a reaction force on the elastic body with respect to the pressing force applied to the elastic body via the pressing means corresponding to the desired output torque A plurality of protrusions are arranged at positions on the circumference of the elastic body where the product of the generated force distribution and the maximum is obtained.

According to the ultrasonic motor of claim 29,
Claim 1, Claim 2, Claim 3, Claim 11, Claim 1
2. In addition to the effects of claim 13 or claim 14, the output of the ultrasonic motor can be maximized. The control method of the ultrasonic motor according to claim 30 is a method for controlling an ultrasonic motor according to claim 4, claim 7,
22. The method of controlling an ultrasonic motor according to claim 8, claim 17, claim 20, or claim 21, wherein an amplitude is detected from the first piezoelectric body, a signal of the amplitude detection and an output signal of the rotation detecting element. Thus, the rotation speed and the rotation angle of the vibrating body or the vibrated body are controlled.

According to the control method of the ultrasonic motor according to the thirtieth aspect, it is possible to prevent the destruction of the first piezoelectric body due to an abnormal input exceeding the distortion limit of the vibrating body beforehand, and the practical effect is obtained. Is big.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view showing the configuration of an ultrasonic motor according to a first embodiment of the present invention, FIG. 2 is an enlarged view of the configuration of a rotation detecting means used in the first embodiment, and FIG. FIG. 4 is a diagram illustrating an example of a vibration mode, FIG. 4 is a diagram illustrating an electrode configuration of a piezoelectric body, and FIG. 5 is a diagram illustrating an operation principle of an ultrasonic motor.

In FIG. 1, reference numeral 1 denotes a first elastic body made of a metal material such as iron, stainless steel, copper, brass, or aluminum, and reference numeral 2 denotes a piezoelectric ceramic or piezoelectric polymer material. The first piezoelectric body 3 is a vibrating body formed by fixing the first elastic body 1 to the first piezoelectric body 2. First
On the elastic body 1, a protrusion 4 is provided in the vicinity of the maximum position of the vibration displacement in the radial direction shown in FIG.

5 is, for example, Teflon, Duracon, PP
The protrusions 4 of the first elastic body 1 made of a plastic material such as S, PES, or PEEK, or a composite material of such a plastic and carbon fiber, graphite, and glass fiber, or a material obtained by bonding these with a metal material. A movable body 6 that is a vibrated body that is brought into contact with the pressure, a bearing 6 for rotatably supporting a rotating shaft 7 fixed integrally with the movable body 5, and a compression 8 between a spring retainer 9 and the bearing 6. This is a compression spring, which is a pressing means disposed in a state, and a disc spring is used in the drawing, but a coil spring or the like may be used. This compression spring 8
The moving body 5 is brought into pressure contact with the vibrating body 3 by the elastic force of. The vibrating body 3 is an elastic member 1 made of an insulating elastic material or the like.
0 and is fixed to the support base 11.

Here, a structure in which the moving body 5 is pressed against the vibrating body 3 is shown. For example, a compression spring 8 is arranged between the elastic member 10 and the support table 11 so that the vibrating body 3 is attached to the moving body 5. The structure which pressurizes may be sufficient. Further, as shown in FIG. 2, the moving body 5 is provided with irregularities 12 formed at regular intervals on its outer peripheral surface, and the irregularity 12 is a rotation detecting element which is a detecting means for detecting the speed and the moving amount of the moving body 5. 15 abuts near its free end. The rotation detecting element 15 includes, for example, a second elastic body 13 made of a metal material such as an iron-based, stainless-based, copper-based, brass-based, or aluminum-based material. A unimorph type having a cantilever structure in which a second piezoelectric body 14 made of a piezoelectric polymer material is attached and one end of which is fixed to a holding member 15a, or a second elastic body 13
Is a bimorph type in which the piezoelectric body 14 is provided.

In the ultrasonic motor constructed as described above, the A and B phases of the two drive electrodes formed on the first piezoelectric body 2 shown as an example in FIG. , Three or more elastic traveling waves are excited in the vibrating body 3 in the radial direction and three or more waves in the circumferential direction, and are applied to the protruding body 4 according to the driving principle shown in FIG. The moving body 5 in pressure contact performs frictional drive at the wave front 4A of the elastic traveling wave and performs rotational movement.

At this time, the second piezoelectric element 14 of the rotation detecting element 15 abutting on the irregularities 12 of the moving body 5 has the irregularities 12 due to the elastic deformation of the second elastic body 13 due to the rotation of the moving body 5.
In this case, a rotational speed and a rotational angle of the moving body 5 are controlled by a pulse signal obtained by generating an induced charge (piezoelectric effect) corresponding to. Next, a control method of the ultrasonic motor configured as described above will be described with reference to FIGS. FIG. 6 is a block diagram showing a control method of the rotation detecting means, and FIG. 7 shows an example of a pulse signal train for explaining the principle of detecting the rotation speed.

In FIG. 6, reference numeral 101 denotes the rotation detecting element 15.
The electric charge induced in the second piezoelectric body 12 corresponding to the irregularities 12 of the moving body 5 is converted into a voltage by, for example, a resistor, impedance-converted by a field-effect transistor, and a pulse voltage is output. A circuit 102 for counting the converted pulse trains per unit time; a comparison circuit 103 for comparing the count value output from the counter circuit 102 with a command value; and a driving circuit 104 based on the result of the comparison circuit 103. A control circuit 105 for controlling the rotation speed of the moving body 5 based on the voltage and the driving frequency. Based on the control circuit 104, a control circuit 105 generates a power amplifier for generating an AC voltage having a different phase to be applied to the first piezoelectric body 2 of the ultrasonic motor. Drive circuit.

That is, the control method of the ultrasonic motor is such that the electric charge induced in the second piezoelectric element 14 of the rotation detecting element in response to the rotation is converted by the conversion circuit by the irregularities 12 formed on the moving element 5 at regular intervals. The electric signal is converted into an electric signal by 101, the electric signal is counted by a counting circuit 102 for a unit time, and control is performed so that the count value of the counting circuit 102 per unit time is equal to a command value of a speed or a rotation angle.

That is, as shown in FIG. 7, since the interval and the total number of the irregularities 12 per one round of the moving body 5 formed at a constant interval are known, if the number of irregularities per unit time is counted, the rotation can be detected. The rotation angle and the number of rotations of the moving body 5 can be obtained by the means, and the rotation of the ultrasonic motor can be controlled by comparing and controlling the values with the command value (set value).

As described above, in the ultrasonic motor according to the first embodiment, the circular first elastic body 1 has the first surface on one side.
A vibrating body 3 having a plurality of projections 4 disposed on the other side of the first elastic body 1 and having a through hole 3a at the center thereof; The first elastic body 1 is disposed on the side of the protrusion 4 and is brought into pressure contact with the protrusion 4, so that at least a portion of the outer peripheral portion that does not contact the protrusion 4 is in contact with the rotation detecting element 15. The moving body 5 having the irregularities 12 formed at regular intervals, and the first piezoelectric body 2 of the first elastic body 1
A support base 11 which is provided on the side and is a support means having a through-hole 11a at the center for supporting the vibrating body 3 via the elastic member 10, and is fixed to the support base 11 by a holding member 15a. Rotation detecting element 15 having a cantilever structure and comprising a second piezoelectric body 14 bonded to a second elastic body 13
And the irregularities 1 formed on the rotation detecting element 15 and the moving body 5
Rotation detecting means for detecting a speed and a rotation angle of the moving body 5 by induced charges generated when the moving body 5 and the moving body 5 come into contact with each other in a tangential direction of the movement of the moving body 5; The rotating shaft 7 fixed to the moving body 5 and the rotating shaft 7 are rotatably supported by extending through the through hole 3a and the through hole 11a at the center of the support base 11, and
Acting on the bearing 6 provided in the through hole 11a of the support base 11 and the rotating shaft 7 to exert an axial force on the rotating shaft 7 to bring the moving body 5 into pressure contact with the protrusion 4 The moving body 5 has a compression spring 8 as pressure means.
Is driven by the first or higher order vibration mode in the radial direction and the three or more elastic traveling waves in the circumferential direction excited by the vibrating body 3 by the AC voltage applied to the vibrating body 3, and the speed and the rotation angle of the moving body 5 by the rotation detecting means. Is detected and controllable.

According to the first embodiment, the rotation speed of the moving body 5 can be directly detected with a simple structure in which the rotation detecting element 15 is brought into contact with the irregularities 12 formed on the outer periphery of the moving body 5, so that the moving The information of the rotation stop of the body 5 and the accuracy of the rotation speed can also be improved. Further, since the irregularities 12 have a constant interval, control can be performed by counting per unit time, and by making the interval of the unit time smaller, counting accuracy can be improved.

Further, since the rotation detecting element 15 has a unimorph or bimorph structure, the rotation detecting element 15 can be miniaturized. In addition, since a voltage is generated by the deformation distortion of the rotation detecting element 15 due to the piezoelectric effect, it is possible to drive the ultrasonic motor with low power consumption. And In the first embodiment, one rotation detecting element 15 is provided on the outer periphery of the moving body 5. However, another rotation detecting element is provided on the moving body 5 on the side opposite to the rotation detecting element 15. Moving body 5 having one rotation detecting element 15
And the uniform contact between the moving body 5 and the vibrating body 3 may be further stabilized, and another structure having the same effect may be adopted.

In the case where the moving body 5 which is the vibrated body is fixed and the vibrating body 3 is relatively moved with respect to the moving body 5, the unevenness 12 with which the rotation detecting element 15 elastically contacts the side surface of the vibrating body 3. To be provided. A second embodiment of the present invention will be described with reference to FIG. FIG. 8 shows an example of a pulse signal sequence for explaining the principle of detecting the rotation speed of the moving body 5 according to the second embodiment.

The configuration of the ultrasonic motor according to the second embodiment is the same as that of the first embodiment except that the circumferential intervals of the irregularities 12 formed on the outer periphery of the moving body 5 are not uniform (random). (Not shown), and the other configuration is the same as that of the first embodiment. The principle of measuring the rotational speed of the ultrasonic motor configured as described above is based on the fact that the number of irregularities 12 formed on the moving body 5 per rotation is known, and therefore the time required for one rotation of the moving body 5, that is, the specified irregularity By measuring the time required to count the number, the rotational speed of the moving body 5 is detected and compared with a command value (set value).

In the control method of the ultrasonic motor according to the second embodiment, the counting circuit 102 in the first embodiment is a time measuring circuit, and the time required for one rotation is determined by the number of electric signals per rotation. Is measured, and control is performed so that the time per one rotation becomes equal to the command value of the speed or the rotation angle, and the other components are the same as those of the first embodiment.

According to the second embodiment, the rotational speed can be detected and controlled without being restricted by the accuracy of forming the irregularities 12 formed on the moving body 5 as compared with the first embodiment. The improvement of the property can be expected. In addition, since the control is performed based on the time required for one rotation of the moving body 5, only the time required for one protrusion interval of the unevenness 12 is a measurement error, so that the rotation can be detected with high accuracy.

Of course, it goes without saying that the detection method of the second embodiment may be applied to the first embodiment or a modification thereof. A third embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a developed view of the outer periphery of the moving body 5 for explaining the principle of detecting the rotation speed of the moving body 5 according to the third embodiment, and FIG. 10 is an ultrasonic motor using the moving body 5 of FIG. Block diagram showing a control method of
FIG. 11 is a sectional view of the ultrasonic motor.

In the third embodiment, the structure of the ultrasonic motor is such that the interval between the irregularities 12 formed on the outer periphery of the moving body 5 is monotonously adjusted during one rotation of the moving body 5 as shown in FIG. It is formed so as to increase or decrease, and the other configuration is the same as that of the first embodiment or the second embodiment. As shown in FIG. 10, this ultrasonic motor control method includes a configuration in which a rotation direction determination circuit 106 is added to the block diagram of FIG. 6 of the first embodiment to determine a rotation direction and control. Has become.

In the third embodiment, the rotation speed and rotation angle of the moving body 5 can be detected by the control methods of the first and second embodiments, but if the rotation direction cannot be determined. It is to solve the problem. In other words, in a moving object having at least N or more convex portions, the time interval of the pulse voltage train continuously generated by the irregularities 12 is continuously measured up to N (N> 3) times, and the previous convex portion is sequentially measured. The rotation direction of the moving body 5 is determined based on the result of the increase or decrease of (N−2 times) in comparison with the time taken in between.

A specific description will be made with reference to FIG. 9 by taking N = 4 as an example. Assuming that the moving body 5 rotates in the direction of the arrow in the drawing, the time relationship between the intervals Δt1 to Δt4 is as follows: Δt1 <Δt2, Δt2> Δt3, Δt3 <Δt4, and N− The rotation direction can be determined by increasing 2 = 2 times, and in the case of the direction opposite to the arrow, the above relationship is reversed,
It can be determined that the rotation has been reversed by decreasing twice. The rotation direction is determined based on such a principle.

According to the third embodiment, it is possible to realize an ultrasonic motor that can detect and control the rotation direction of a moving body with a simple configuration without adding another sensor. In this respect, in the related art, the direction of the elastic traveling wave can be changed by changing the phase relationship between the two drive voltages, and the rotation direction of the moving body 5 can be changed. Even in driving, the rotation direction is reversed, so that the rotation direction cannot be detected and controlled, and a sensor for determining another rotation direction is required.

FIG. 11 further shows the first and second embodiments in the radial direction of the surface of the vibrating body 3 of the ultrasonic motor 3 on which the projections 4 of the first elastic body 1 are formed. The step 1a is formed, and the thickness of the first elastic body 1 is made non-uniform, and the same reference numerals are given to parts common to the first embodiment. With this configuration, the first
The resonance resistance of the vibrating body 3 is reduced by reducing the bending stiffness of the inner peripheral portion of the elastic body 1, and the vibration displacement with respect to the same input power as the uniform vibrating body without the thickness of the first elastic body 1 being non-uniform. Since the amount can be increased, a more efficient ultrasonic motor can be realized.

It goes without saying that the structure of the vibrating body 3 according to the third embodiment may be applied to each of the following embodiments. Further, although the example in which the thickness of the first elastic body 3 is different in the two portions in FIG. 11 is shown, the thickness may be continuously changed in the radial direction or may be changed in a plurality of places. A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a sectional view showing an ultrasonic motor according to the fourth embodiment. This fourth embodiment is different from the first to third embodiments in that a vibrator having a secondary vibration mode in the radial direction as shown in FIG. This is applied to a vibrating body 16 having a projection 17 formed at a position where the output from the motor can be taken out to a maximum when the vibrating body excited in the next vibration mode is miniaturized.

That is, in the case of the secondary vibration mode in the radial direction, the projection 17 is formed at the maximum displacement position shown in FIG.
The entire surface of the node (node) or the vibrating body 16 on the piezoelectric body side is elastic member 1
The vibrator has a structure that can be supported by zero. The determination of the position of the projection 17 in the case of a small ultrasonic motor driven in the primary vibration mode in the radial direction will be described with reference to FIG.

FIG. 14B shows that, when the primary vibration mode is excited in the radial direction, the vibration displacement curve θ _{1 in the} radial direction and the pressing force applied to the vibrating body 16 by the compression spring 8 are shown. The distribution of a radial force generated by the vibrating body 16 as a reaction force, that is, a relative generated force curve θ ₂ to an external load is shown. The pressing force applied to the vibrating body 16 by the compression spring 8 is determined by the output torque required as a characteristic of the ultrasonic motor.

The output that the vibrating body 16 can output can be obtained from the following relationship. Output = speed × force Since the speed is the time derivative of the vibration displacement, the vibration displacement curve (velocity curve) θ ₁ and the generated force distribution (relative generated force curve with respect to an external load) θ ₂ in FIG. The output curve θ ₃ is obtained from the product. The maximum point P of the output curve θ ₃
If the projections 17 are provided, the position of the projections 17 at which the output of the ultrasonic motor can be maximized with respect to the pressing force uniquely determined by the required torque can be determined.

By applying the first to third embodiments to the ultrasonic motor having the protrusion 17 determined by the above method, it is possible to reliably support and fix the vibration displacement at the node position. It is possible to arbitrarily control the rotation speed, the rotation angle, and the rotation direction of an ultrasonic motor including a vibrating body and a vibrating body capable of extracting maximum output from a small ultrasonic motor.

The support 11 is pressed by the compression spring 8 to press the vibrator 3 via the elastic member 10, and the vibrator 3 is fixed to the support 11 by the frictional force with the elastic member 10. The elastic member 10 fixed to the support base 11
An air layer that can fix the vibrating body 16 to the support 11 while maintaining electrical insulation from the support 11 without hindering the elastic vibration excited by the first piezoelectric body 2 is included. It is preferable to use a buffer made of an insulating material. Above all, it is more preferable to use felt as the cushioning material, and it goes without saying that the present invention is not limited to the fourth embodiment and can be applied to any of the other embodiments.

A fifth embodiment of the present invention will be described with reference to FIG. FIG. 15 is a sectional view of an ultrasonic motor according to a fifth embodiment of the present invention. In the figure,
The difference from the fourth embodiment is that the vibrating body 16 is
That is, the supporting member 18 is rotatably supported in a direction perpendicular to the direction, specifically, a point that a supporting member 18 is used. This support member 1
8 has one end in the axial direction fixed to the inner peripheral portion of the first elastic body 1 and the other end having a convex-shaped portion 18b forming a hemispherical surface. The convex shape portion 18b of the support member 18
As shown in the figure, it is in contact with a tapered inverted conical recess 19 a formed in the center of the support base 19.

A through hole 18a having an inner diameter slightly larger than the diameter of the rotating shaft 7 is formed at the center of the supporting member 18, and the rotating shaft 7 passing through the through hole 18a is rotatably held by a bearing. I have. In the fifth embodiment, unlike the fourth embodiment, no cushioning material is used between the vibrating body 16 and the support 19, and both are in a non-contact state.

As described above, in the ultrasonic motor according to the fifth embodiment, the circular first elastic body 1 has the first surface on one side.
A vibrating body 16 having a through-hole 16a at the center, comprising a plurality of projections 17 disposed on the other surface of the first elastic body 1; The elastic body 1 is disposed on the side of the projection 17 and is brought into pressure contact with the projection 17, and at an outer peripheral portion that does not come into contact with the projection 17, at least at a portion where the rotation detecting element 15 abuts, so as to have a predetermined interval. A movable body 5 having irregularities 12 formed thereon, and a first elastic body 1 disposed on the first piezoelectric body 2 side, and having a through hole 19b at the center thereof;
At the end on the side facing the vibrating body 16, a support base 19, which is a supporting means in which a concave portion 19 a having a tapered inclined surface whose hole diameter gradually increases, is formed. Is provided on the piezoelectric body 2 side, and has a through hole 18a at the center portion through which the rotating shaft 7 passes. One end of the through hole 18a is fixed to the elastic body 1, and the other end is provided with support means. A support member 18 for fixing and supporting the vibrating body 16 is formed with a convex-shaped portion 18b which is aligned with the concave portion 19a of the support base 19 which is
A rotation detecting element 15 having a cantilever structure, which is fixed to a support base 19 by a holding member 15a and is composed of a second piezoelectric body 14 bonded to a plate-like second elastic body 13; Rotation detecting means for detecting a speed and a rotation angle of the moving body 5 by induced charges generated when the element 15 and the unevenness 12 formed on the moving body 5 come into contact with each other in a tangential direction of the movement of the moving body 5; 5 from the center
6 and the through hole 1 at the center of the support base 19.
A rotating shaft 7 fixed to the moving body 5 extending so as to penetrate through the rotating shaft 9b, and a support base 1 rotatably supporting the rotating shaft 7;
Pressurizing means which acts on the bearing 6 disposed in the through hole 19 b of the ninth embodiment 9 and the rotating shaft 7 to exert a force in the axial direction on the rotating shaft 7 to bring the moving body 5 into pressure contact with the protrusion 4. And the convex shape portion 18b of the support member 18 is brought into pressure contact with the concave portion 19b of the support base 19 by the force of the compression spring 8, and the vibrating body 16 is supported by the support base 19, and the moving body 5 Is
The vibration body 16 is driven by a vibration mode of first or more order in the radial direction excited by the vibrating body 16 by the AC voltage applied to the piezoelectric body 2, and three or more elastic traveling waves in the circumferential direction.
This controls the speed and the rotation angle.

According to the fifth embodiment, the vibrating bodies 3 and 16 of the first to fourth embodiments come into contact with the support base 11 via the elastic member 10 made of a cushioning material. In the configuration, a loss occurs due to absorption of vibration energy, whereas in the fifth embodiment, FIGS.
Since the vibrating body 16 is supported at a position where it does not vibrate as shown in (1), there is almost no loss of vibration energy, the vibration energy can be effectively extracted from the vibrating body 16, and the efficiency of the ultrasonic motor can be improved.

Further, since the convex-shaped portion 18b of the support member 18 is in contact with the concave portion 19a of the support base 19, the support member 18 can be freely inclined in a state of contact with the concave portion 19a. Therefore, the vibrating body 16 fixed to the supporting member 18 can also be freely tilted, and as a result, the moving body 5 is not affected by an external load such as a lateral pressure applied to the moving body 5.
The contact state between the first elastic body 1 and the projection 17 can be made uniform.

In addition, the support member 18 can be tilted by appropriately setting the shape and size relationship of each part, for example, by setting the difference between the inner diameter of the support member 18 and the outer diameter of the rotating shaft 7 appropriately large. Since the angle range can be widened, it is more preferable to realize a uniform contact state between the moving body 5 and the vibrating body 16. In the fourth embodiment, the elastic member 10 made of the cushioning material is inevitably changed with time in the thickness of the supporting member 18 due to the influence of the pressing force in long-term use. In the embodiment, such a dimensional deformation does not occur, and an even more reliable ultrasonic motor can be realized.

It is needless to say that the projection 17 may be formed on the outer peripheral portion of the vibrator 16 in the same manner as described in the first embodiment. Further, the fifth aspect of the present invention.
The recess 19a of the support base 19 in the embodiment of FIG.
6 (a) and FIG. 16 (b), it has a tapered shape, but an inverted quadrangular pyramid-shaped concave portion 19b and an inverted triangular pyramid-shaped concave portion 1
9c, as long as it has a shape that contacts at least three points with the spherical convex shape portion 18b of the support member 18, the shape is not particularly limited.

In the fifth embodiment, FIG.
As shown in FIG. 3, the convex shape portion 20 of the support member 18 has a substantially half-spheroidal shape, and the concave portion 21 of the support base 19 has a long axis a and a short axis b.
May be fitted to each other as a substantially semi-spheroidal shape. This is because the vibrating body 16 is
Therefore, a force for rotating the vibrators 3 and 16 in a direction opposite to the rotation direction of the moving body 5 is received as a reaction. This reaction force is applied to the convex shape portion 18 b of the support member 18 and the concave portion 1.
9a is canceled out by the frictional force generated at the pressure contact portion with the convex shape portion 20 and the concave portion 2 as described above.
If 1 is a spheroidal shape that matches each other, the support member 18 cannot rotate, so that the rotation of the vibrating body 3 in the reverse direction due to the above-described reaction can be completely prevented.

In the first to fifth embodiments, the unevenness 12 is provided so as to penetrate the outer peripheral surface of the moving body 5, but a penetrating structure is not particularly required, and the rotation detecting element is not required. The same function can be realized if the unevenness 12 is provided in a portion where it comes into contact with 15. Also, as shown in FIG. 18, it is needless to say that the unevenness 12 may be formed on the surface of the moving body 5 which is not in contact with the projections 4 and 17, and the rotation detecting element 15 may contact the unevenness 12. If they do not come into contact with the moving body 5, the irregularities 12
May be formed.

Further, the first embodiment to the fifth embodiment
In the second elastic body 13 of the rotation detecting element 15 according to the embodiment, as shown in FIG. 19A, a convex portion 22 is formed on a surface of the moving body 15 which comes into contact with the unevenness 12, or as shown in FIG.
The curved portion 23 is formed as shown in FIG.
The rotation resistance may be reduced due to the contact in the rotation direction, and the tip portion may be prevented from being caught by the irregularities 12.

Further, the first embodiment to the fifth embodiment
It is not particularly necessary to form the unevenness 12 directly on the moving body 5 as in the embodiment described above, and the above-described function of the unevenness 12 is realized by fitting the unevenness member 24 to the moving body 5 as shown in FIG. It may be configured. The moving body 5 may be configured to be rotatable in a direction orthogonal to the rotation shaft 7.

A sixth embodiment of the present invention will be described with reference to FIGS. FIG. 21 is a sectional view showing the configuration of an ultrasonic motor according to a sixth embodiment of the present invention, and FIG. 22 is an enlarged view showing the configuration of the rotation detecting means.
In the figure, the difference from the first embodiment is that
The configuration and the control method are the same as those of the first embodiment.

According to the sixth embodiment, the unevenness 12 is formed on the rotating shaft 7 having a small rotating radius, and the rotation detecting element 1
5 is brought into contact with the irregularities 12 so that the rotation detecting element 15
Since the rotation resistance due to the contact of the moving body 5 can be reduced, the influence on the driving torque of the moving body 5 is small, and the rotation speed and the rotation angle of the moving body 5 can be controlled without deteriorating the characteristics.

Similarly, FIGS. 23 and 24 are sectional views showing the configuration when the sixth embodiment is applied to the structures of the fourth and fifth embodiments. Although the same reference numerals are given to the portions, it goes without saying that the same effect can be obtained. It should be noted that the irregularities 12 are provided on the rotating shaft 7 and the irregularities 12 on the outer peripheral portion of the moving body 5 are deleted, so that the first to fifth embodiments can be applied to the sixth embodiment. is there. Further, as shown in FIG. 20, a configuration in which the concavo-convex member 24 is directly fitted to the rotating shaft 7 may be employed.

FIG. 25 and FIG. 26 show a seventh embodiment of the present invention. FIG. 25 is a sectional view showing the configuration of an ultrasonic motor according to a seventh embodiment of the present invention, and FIG. 26 is an enlarged view of the configuration of the rotation detecting element. In these figures, a concave / convex slit 25 is formed in the outer peripheral portion of the moving body 5, and opposing electrodes 26 a, which are arranged opposite to the upper and lower surfaces of the moving body 5 so as to cover at least both ends of the slit 25.
This is an ultrasonic motor configuration including a rotation detecting element 26 composed of 26b, and the other configuration is the same as that of the first embodiment.

The counter electrode 26 of the rotation detecting element 26
a, 26b formed between the opposing electrodes 26a, 26b by passing the uneven slit 25 between
The rotation speed of the moving body 5 and the rotation speed of the moving body 5 are changed due to a change in the electrode spacing between the case where the protrusions 5 are provided and the slit 25 where the protrusions are not provided, and a change due to the rotation of the capacitance due to the presence or absence of a substance having a different dielectric constant. Detect and control the rotation angle.

As described above, in this ultrasonic motor, the piezoelectric body 2 is fixed to one surface of the circular elastic body 1 and the plurality of projections 4 are arranged on the other surface of the elastic body 1. Vibrating body 3 having a through hole 3a at the center, and elastic body 1
A moving body 5 which is provided on the side of the protrusion 4 and is press-contacted with the protrusion 4 and has slits 25 of irregularities formed at regular intervals in a thickness direction on an outer peripheral portion from a position where the protrusion 4 contacts the elastic body; 1
A support base 11 which is provided on the side of the piezoelectric body 2 for supporting the vibrating body 3 via the elastic member 10 and which is a support means having a through hole 11a in the center, and a holding member 2 provided on the support base 11
The counter electrode 26 fixed at 6a and opposed to the upper and lower slits 25 formed in the movable body 5 in a non-contact manner in the thickness direction.
a rotation detecting means for detecting the speed and rotation angle of the moving body 5 by a rotation detecting element 26 comprising
A rotating shaft 7 fixed to the moving body 5 and extending from a central portion of the vibrating body 3 so as to pass through the through hole of the vibrating body 3 and the through hole 11a of the central portion of the support base 11, and rotatably supports the rotating shaft 7. Bearing 6 disposed in the through hole 11a of the support base 11
And a compression spring 8 acting as pressure means for acting on the rotation shaft 7 to exert a force in the axial direction on the rotation shaft 7 to press the moving body 5 against the projection 4. 5 is a piezoelectric body 2
Is driven by the first or higher order vibration mode in the radial direction and the three or more elastic traveling waves in the circumferential direction excited by the vibrating body 3 by the AC voltage applied to the vibrating body 3, and the speed and the rotation angle of the moving body 5 by the rotation detecting means. Is controlled.

According to the seventh embodiment, since the rotation detecting element 26 can detect rotation without contacting the moving body 5,
An ultrasonic motor that achieves uniform contact between the moving body 5 and the projection 4 without being affected by a decrease in driving torque or side pressure can be obtained. Note that a structure may be used in which a conductive material is used as the material of the moving body 5 or a conductive film is formed on the upper and lower surfaces of the moving body 5 to short-circuit. According to these structures,
Since the capacitance of the protrusion is eliminated, the change in capacitance inversely proportional to the electrode interval of the rotation detecting element 26 can be further increased, and the S / S
Improvement of the detection accuracy can be realized by improvement of the N ratio, which is a more preferable embodiment.

In the seventh embodiment, the counter electrodes 26a and 26b are arranged above and below the unevenness formed on the outer periphery of the moving body 5 in the rotation detecting element 26. Needless to say, a rotation detecting element structure having opposing electrodes 26a and 26b opposite to the above may be used. Further, the uneven slit 25 formed in the moving body 5
There is no problem with a structure in which a substance made of a high dielectric constant material is filled. Of course, a structure in which the moving body 5 itself is formed of a high dielectric substance and the slit 25 is not filled may be used.

A control method of the ultrasonic motor according to the seventh embodiment will be described below. The basic configuration is the same as that of the first to third embodiments, and the conversion circuit 10
1 is different in that the capacitance is converted into a voltage. As a specific method, after converting into a voltage using a general balanced bridge circuit or the like, the rotation speed of the moving body 5 is controlled by the same control method. That is, the control method of the ultrasonic motor is such that the rotation detecting element 2
6 is converted into an electric signal by a conversion circuit, and the electric signal is counted for a unit time by a counting circuit;
The control is performed so that the count value of the counting circuit per unit time is equal to the command value of the speed and the rotation angle.

In addition, as in the case of the second embodiment, when the interval between the uneven slits is not uniform, the moving body 5
A conversion circuit for converting a change in capacitance induced in the rotation detecting element 26 into an electric signal corresponding to the rotation of the moving body 5, and a time measuring circuit for measuring a time required for one rotation from the number of electric signals per rotation of the moving body 5 The control is performed such that the time per one rotation becomes equal to the command value of the speed and the rotation angle.

Further, a rotation direction discriminating circuit is provided to detect the rotation direction in response to the case where the interval between adjacent slits of the concavo-convex increases or decreases within one rotation as in the third embodiment. Control. FIG. 27 and FIG. 28 are sectional views of the configuration when the seventh embodiment is applied to the fourth and fifth embodiments. Needless to say, the same effects can be obtained with these configurations.

That is, in the ultrasonic motor shown in FIG. 28, the piezoelectric body 2 is fixed to one surface of the circular elastic body 1 and the elastic body 1
A vibrating body 16 having a plurality of projections 17 disposed on the other surface thereof and having a through hole 16a in the center, and a projection disposed on the projection 17 side of the elastic body 1. The moving body 5 is provided on the piezoelectric body 2 side of the elastic body 1 and is provided with a concave and convex slit 25 at regular intervals on the outer peripheral portion from the position where the moving body 5 is in contact with the projecting body 17. A support base 19 having a hole 19a and having a concave portion 19a having a tapered slope formed at an end on the side facing the vibrating body 16 and having a gradually increasing hole diameter, and a piezoelectric body 2 of the elastic body 1 Arranged on the side,
The center portion has a through hole 18a through which the rotating shaft 7 penetrates. One end of the through hole 18a is fixed to the elastic body 1 and the other end has a convex shape matching the concave portion 19a of the support base 19. A support member 18 having a portion 18b formed therein for fixing and supporting the vibrating body 16 is fixed to a support base 19 by a holding member 26a, and is not in contact with the upper and lower slits 25 formed in the moving body 5 in the thickness direction. Electrodes 26a, 26 facing the
b, a rotation detecting means for detecting the speed and rotation angle of the moving body 5, and a through hole 16 a of the vibrating body 16 and a through hole at the center of the support base 19 from the center of the moving body 5. A rotating shaft 7 fixed to the moving body 5 extending so as to penetrate through the base 19b, and a bearing 6 disposed in a through hole 19b of the support base 19 for rotatably supporting the rotating shaft 7.
Acting on the rotating shaft 7 to exert a force in the axial direction on the rotating shaft 7 to press the moving body 5 against the protruding body 17. As a result, the convex shape portion 18 b of the support member 18 is
a, the vibrating body 16 is supported by the support base 19, and the moving body 5 is driven in the radial direction excited by the vibrating body 16 by the AC voltage applied to the piezoelectric body 2. , And is driven by three or more elastic traveling waves in the circumferential direction, and the speed and the rotation angle of the moving body 5 are controlled by the rotation detecting means.

FIG. 29 and FIG. 30 show an eighth embodiment of the present invention. FIG. 29 is a sectional view showing the configuration of an ultrasonic motor according to an eighth embodiment of the present invention, and FIG. 30 is an enlarged view of the configuration of the rotation detecting means. In FIG. 30, a conductive film 27 having an uneven shape is formed on the surface of the moving body 5 opposite to the protrusion 4, and the uncoated portion 2 corresponding to the concave portion of the conductive film 27 is formed.
A first opposing electrode 29 and at least a conductive film 27 which are disposed so as to cover at least
Of the second opposing electrode 3 which is arranged with a space between the projections 27a
This is an ultrasonic motor configuration including a rotation detection element 31 made of zero, the other configuration is the same as that of the first embodiment, and the control method is the same as that of the seventh embodiment.

Then, the capacitance between the first opposing electrode 29, the second opposing electrode 30 and the conductive film 27 of the rotation detecting element 31, and the non-adhesion of the first opposing electrode 29 and the second opposing electrode 30 The rotation speed and the rotation angle of the moving body 5 are detected and controlled based on a change accompanying the rotation with the capacitance when the opposing electrodes 29 and 30 are released when opposing the unit 28. That is, when the first opposing electrode 29 faces the protruding portion 27 a of the conductive film 27, the second opposing electrode 30 also protrudes from the protruding portion 2 of another conductive film 27.
7a, two capacitors are connected in series between the first counter electrode 29 and the conductive film 27 and between the second counter electrode 30 and the conductive film 27. Next, when the first opposing electrode 29 and the second opposing electrode 30 face the uncoated portion 28 corresponding to the concave portion of the conductive film 27, the first opposing electrode 29 and the second opposing electrode 30 During that time, the capacitor is electrically open and no capacity is generated. Based on these two states, the rotation speed and rotation angle of the moving body 5 are detected and controlled.

As described above, in this ultrasonic motor, the piezoelectric body 2 is fixed to one surface of the circular elastic body 1 and the plurality of protrusions 4 are provided on the other surface of the elastic body 1. Vibrating body 3 having a through hole 3a at the center, and elastic body 1
And a conductive film 27 having a plurality of conductor-free portions at regular intervals on the surface opposite to the surface that comes into contact with the protrusion 4 under pressure. And a center portion for supporting the vibrating body 3 disposed on the piezoelectric body 5 side of the elastic body 1 via the elastic member 10 and a moving body 5 formed of a material having a high resistivity. A support base 11 which is a support means having a through hole 11a, and a conductive film 2 fixed to the support base 11 by a holding member 31a and formed on the moving body 5
7 and a pair of opposing electrodes 2 provided in opposition to each other.
A rotation detection element 31 for detecting the speed of the moving body with a rotation detecting element 31 having a through-hole 3a of the vibrating body 3 and a through-hole 1 at the center of the support base 11;
1a, a rotating shaft 7 fixed to the moving body 5 extending therethrough, and a support base 1 rotatably supporting the rotating shaft 7.
Acting on the bearing 6 disposed in the through hole 11a and the rotating shaft 7 to exert a force in the axial direction on the rotating shaft 7,
A compression spring 8 which is a pressing means for bringing the moving body 5 into pressure contact with the protrusion 4, and the moving body 5 is moved in the radial direction excited by the vibrating body 3 by the AC voltage applied to the piezoelectric body 2. It is driven by three or more elastic traveling waves in the circumferential direction in the first or higher vibration mode, and the speed and the rotation angle of the moving body 5 are controlled by the rotation detecting means.

As a method of controlling the ultrasonic motor,
The first to third embodiments can be adopted. For example, similarly to the third embodiment, the conductive film 27 can be used.
The portion where the conductor exists and the portion where the conductor does not exist are configured to monotonically increase or decrease within one rotation, and at least N (N> 4) or more conductors of the conductive film 27 formed on the moving body 5 are formed. In the existing part, the capacitance change induced in the rotation detecting element 31 is converted into an electric signal by a conversion circuit in accordance with the rotation of the moving body 5, and at least four or more N-1 time intervals of the continuous electric signal are used. Are sequentially compared by a comparison circuit, and the rotation direction of the moving body 5 is detected and the rotation direction is controlled by detecting at least two or more N−2 increase or decrease times.

According to the eighth embodiment, the effects of the seventh embodiment can be obtained, and the opposing electrodes 29 and 3 can be obtained.
Since the distance between 0 and the conductive film 27 can be made as small as possible,
The detection capacity that increases in inverse proportion to the interval increases, and the detection accuracy can be improved. Further, the area can be increased as compared with the area of the counter electrode above and below the uneven slit 25, and the detection capacity can be further increased.

In this case, the moving body 5 is preferably made of a non-conductive material. However, the moving body 5 is not limited to this as long as it has a large difference in resistivity as compared with the conductive film 27. Although the conductive film 27 is formed on the upper surface of the moving body 5, the present invention is not limited to this. For example, as shown in FIG. To form a conductive film 27 on the surface of the protrusion on the outer peripheral side surface of the moving body 5 and on the upper surface of the moving body 5.
A configuration in which the first opposing electrode 29 and the second opposing electrode 30 are arranged side by side so as to face between the convex portions, It is needless to say that a configuration in which the counter electrodes 29 and 30 of the rotation detecting element 31 are opposed to each other in the diameter direction of the moving body 5 may be adopted.

FIGS. 32 and 33 are sectional views showing the configuration when the eighth embodiment is applied to the fourth and fifth embodiments. It is needless to say that the same effects as those of the seventh embodiment can be obtained in these configurations. For example, the ultrasonic motor shown in FIG.
A vibrating body 16 having a through-hole 16a at the center formed by fixing the piezoelectric body 2 on one surface of the elastic body 1 and arranging a plurality of protrusions 17 on the other surface of the elastic body 1. A portion which is disposed on the protrusion 17 side of the elastic body 1 and is brought into pressure contact with the protrusion 17 and has a plurality of conductor-free portions at regular intervals on the surface opposite to the surface in contact with the protrusion 17. A moving body 5 formed of a material having a high resistivity, on which a conductive film 27 having
The elastic body 1 is provided on the piezoelectric body 2 side, and a through hole 19 is provided at the center.
b, a support base 19 which is a support means in which a concave portion 19 a having a tapered slope is formed at an end portion on a side facing the vibrating body 16, the diameter of which gradually increases. It is provided on the piezoelectric body 2 side, and has a through hole 18a at the center portion through which the rotating shaft 7 penetrates. One end of the through hole 18a is fixed to the elastic body 1, and the other end is provided with a support base. 19 recesses 1
A support member 18 for fixing and supporting the vibrating body 19 is formed with a convex-shaped portion 18b fitted and aligned with the support base 9a.
9, a rotation detecting element 31 having a pair of opposed electrodes 29 and 30 provided opposite to each other without contacting the conductive film 27 formed on the moving body 5 with the holding member 26a.
Rotation detecting means for detecting the speed and rotation angle of the moving body 5, and the moving body 5 extending from the center of the moving body 5 so as to pass through the through hole 16a of the vibrating body 16 and the through hole 19b of the center of the support base 19. , A bearing 6 disposed in a through hole 19b of a support stand 19 for rotatably supporting the rotating shaft 7, and acting on the rotating shaft 7 so that the rotating shaft 7 The compression spring 8 is a pressing means for applying a force in the direction to press the moving body 5 against the projection 17, and the convex-shaped portion 18 b of the support member 18 is moved by the force of the pressing means.
9, the vibrating body 16 is supported by the support base 19, and the moving body 5 is first-order or higher in the radial direction excited by the vibrating body 16 by the AC voltage applied to the piezoelectric body 2. Is driven by three or more elastic traveling waves in the circumferential direction, and the speed and rotation angle of the moving body 5 are controlled by the rotation detecting means.

In each of the above embodiments, various rotation detecting means have been described. For example, the first piezoelectric member 2 used in each of the embodiments may be provided with a C portion or a D portion shown in FIG.
A vibration detecting electrode is formed in a portion or the like, and the rotation detecting element 15 or the like is used for detecting the rotation of the moving body 5, and at the same time, the amplitude of the vibrating body 3 or the like is monitored by the vibration detecting electrode of the first piezoelectric body 2. When the rotation is abnormal, for example, when the rotation detecting element 15 or the like detects the rotation stop state, the first applied to realize the command value
It is also possible to adopt a configuration in which the abnormal input to the piezoelectric body 2 is controlled so as to be restricted. With such a configuration, it is possible to prevent damage to the first piezoelectric body 2 due to an abnormal input exceeding the distortion limit of the vibrating body 3 or the like beforehand, which is extremely effective in practice. is there.

[0100]

According to the ultrasonic motor of the first aspect,
When an electric signal is input to the first piezoelectric body and the vibrating body vibrates, the vibrated body or the vibrating body moves. As a result, the second elastic body of the rotation detecting element vibrates because the unevenness moves,
An electric charge is induced by the deformation and distortion of the second piezoelectric body. Therefore, the rotation speed and the rotation angle can be controlled by detecting and measuring this charge. As a result, the detection accuracy is higher than before, the characteristics are not reduced, the device can be downsized, and the cost can be reduced without the need to provide a detection device more expensive than the ultrasonic motor.

According to the ultrasonic motor of the second aspect, in addition to the effect of the first aspect, the unevenness is formed on the rotating shaft having a small rotation radius. , The influence on the driving torque of the vibrating body or the vibrated body is reduced, and the rotation speed and the rotation angle can be controlled without deteriorating the characteristics. According to the ultrasonic motor of the third aspect, in addition to the effect of the first aspect, the convex member slides in the concave portion so that the support member can rotate with respect to the support means and the vibrating member or the vibrating member can be pivoted. Since it can be tilted with respect to the direction, the contact state between the protrusion and the vibrating body that comes into contact with the protruding body against external load such as lateral pressure applied to the vibrating body or the vibrated body can be uniform, and Since an elastic member interposed between the fixed side of the body and the support means is not required, it is not necessary to consider a temporal change of the elastic member due to long-term use.

According to the control method of the ultrasonic motor according to the fourth aspect, stable rotation can be obtained with high accuracy. According to the ultrasonic motor of the fifth aspect, in addition to the effects of the first, second, and third aspects, the rotational speed can be detected and controlled without being restricted by the accuracy of forming the unevenness, thereby improving the productivity. Can be expected. In addition, control can be performed based on the time required for one rotation of the vibrating body or the vibrated body or the rotating shaft, and rotation can be detected with high accuracy.

According to the ultrasonic motor of the sixth aspect, in addition to the effects of the first, second and third aspects, it is possible to detect the rotational direction of the vibrating body or the vibrated body. According to the control method of the ultrasonic motor according to claim 7,
This has the same effect as the fourth aspect. According to the ultrasonic motor control method of the eighth aspect, an ultrasonic motor capable of detecting and controlling a moving direction such as a rotating direction of a vibrating body or a vibrated body with a simple configuration without adding another sensor is provided. Can be realized.

According to the ultrasonic motor of claim 9, claim 1, claim 2, claim 3, claim 5, or claim 6
In addition to the effects described above, it is possible to prevent the second elastic body from being caught by the irregularities, and to reduce the rotational resistance due to the contact of the irregularities in the rotation direction. According to the ultrasonic motor of the tenth aspect, the same effect as the first, second, third, fifth, sixth or ninth aspects is obtained.

According to the ultrasonic motor of the eleventh aspect,
Since the opposing electrode of the rotation detecting element opposes the unevenness in a non-contact manner, uniform contact between the protruding body and the vibrated body can be realized without the influence of a decrease in driving torque or side pressure. According to the ultrasonic motor of the twelfth aspect, in addition to the effect of the eleventh aspect, there is the same effect as that of the third aspect.

According to the ultrasonic motor of the thirteenth aspect,
In addition to having the effect of claim 11, the distance between the counter electrode and the conductive film can be made as small as possible, so that the detection capacitance that increases in proportion to the distance can be increased and the facing area can be increased, so that the capacitance can be further increased. , Detection accuracy can be improved. According to the ultrasonic motor of the fourteenth aspect, in addition to the effect of the thirteenth aspect, the same effect as the third aspect is obtained.

According to the ultrasonic motor of the fifteenth aspect,
This has the same effect as the eleventh or twelfth aspect. Claim 1
According to the ultrasonic motor described in claim 6, claim 11 and claim 1
2 or the same effect as in claim 15. According to the ultrasonic motor control method of the seventeenth aspect, the same effect as that of the fourth aspect is obtained.

According to the ultrasonic motor of the eighteenth aspect,
This has the same effect as the fifth aspect. According to the ultrasonic motor of the nineteenth aspect, the same effect as the sixth aspect is obtained. According to the ultrasonic motor control method of the twentieth aspect, the same effect as that of the seventh aspect can be obtained. According to the ultrasonic motor control method of the twenty-first aspect, the same effect as the eighth aspect is obtained.

According to the ultrasonic motor of the twenty-second aspect,
The effects of claim 1, claim 2 or claim 11 are obtained. According to the ultrasonic motor of the twenty-third aspect, the effect of the twenty-second aspect is obtained. According to the ultrasonic motor described in claim 24, claim 1, claim 2, claim 3, claim 11, or claim 1
2. In addition to the effects of claim 13 or claim 14, the same as a uniform vibrating body that reduces the resonance resistance of the vibrating body by reducing the bending stiffness of the inner peripheral portion of the elastic body and does not make the thickness of the elastic body non-uniform. The amount of vibration displacement can be increased with respect to the input power, and a more efficient ultrasonic motor can be realized.

According to the ultrasonic motor of claim 25,
This has the same effect as the tenth aspect. According to the ultrasonic motor of the twenty-sixth aspect, the same effect as the eleventh or twelfth aspect is obtained. According to the ultrasonic motor of the twenty-seventh aspect, the same effects as those of the third, twelfth, and fourteenth aspects are obtained.

According to the ultrasonic motor of the twenty-eighth aspect,
In addition to the effects of the third, twelfth, and fourteenth aspects, a rotational reaction force of the vibrating body or the vibrated body can be easily prevented. According to the ultrasonic motor of claim 29, in addition to the effects of claim 1, claim 2, claim 3, claim 11, claim 12, claim 13 or claim 14, the output of the ultrasonic motor is Can be maximized.

According to the ultrasonic motor control method of the thirtieth aspect, it is possible to prevent the vibrating body from being broken by an abnormal input exceeding the distortion limit of the first piezoelectric body, thereby realizing a practical effect. Is big.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an ultrasonic motor according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing a rotation detecting unit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a radial primary vibration displacement distribution of an ultrasonic motor.

FIG. 4 is an electrode configuration diagram of a piezoelectric body used in an ultrasonic motor.

FIG. 5 is an explanatory diagram showing the operation principle of the ultrasonic motor.

FIG. 6 is a block diagram showing a control method of the ultrasonic motor according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating the principle of a method of controlling the ultrasonic motor according to the first embodiment of the present invention.

FIG. 8 is a diagram illustrating the principle of a method of controlling an ultrasonic motor according to a second embodiment of the present invention.

FIG. 9 is a diagram illustrating the principle of a method for controlling an ultrasonic motor according to a third embodiment of the present invention.

FIG. 10 is a block diagram illustrating a control method of an ultrasonic motor according to a third embodiment of the present invention.

FIG. 11 is a cross-sectional view of an ultrasonic motor showing a modification of the first embodiment or the like of the present invention.

FIG. 12 is a sectional view of an ultrasonic motor according to a fourth embodiment of the present invention.

FIG. 13 is an explanatory view showing a secondary vibration displacement distribution in the radial direction of the ultrasonic motor.

FIGS. 14A and 14B are explanatory diagrams of the principle for determining the position of the protrusion of the vibrating body, wherein FIG. 14A is a perspective view of the vibrating body, and FIG.

FIG. 15 is a sectional view of an ultrasonic motor according to a fifth embodiment of the present invention.

FIG. 16 is a perspective view showing the structure of another support base that can be used in the fifth embodiment.

FIG. 17 is a perspective view of another support base provided with a rotation stop mechanism usable in the fifth embodiment.

FIG. 18 is a perspective view showing a configuration of another moving body that can be used in the first to fifth embodiments of the present invention.

FIG. 19 is a perspective view showing a configuration of another rotation detecting element usable in the first to fifth embodiments of the present invention.

FIG. 20 is a perspective view showing a configuration of a moving body fitted with a concave-convex member usable in the first to fifth embodiments of the present invention.

FIG. 21 is a sectional view of an ultrasonic motor according to a sixth embodiment of the present invention.

FIG. 22 is an enlarged perspective view showing a rotation detecting means according to a sixth embodiment of the present invention.

FIG. 23 is a sectional view of an ultrasonic motor showing a modification of the sixth embodiment of the present invention.

FIG. 24 is a sectional view of an ultrasonic motor showing another modification of the sixth embodiment of the present invention.

FIG. 25 is a sectional view of an ultrasonic motor according to a seventh embodiment of the present invention.

FIG. 26 is an enlarged perspective view showing a rotation detecting means according to a seventh embodiment of the present invention.

FIG. 27 is a sectional view of an ultrasonic motor showing a modification of the seventh embodiment of the present invention.

FIG. 28 is a sectional view of an ultrasonic motor showing another modification of the seventh embodiment of the present invention.

FIG. 29 is a sectional view of an ultrasonic motor according to an eighth embodiment of the present invention.

FIG. 30 is an enlarged perspective view showing a rotation detecting means according to an eighth embodiment of the present invention.

FIG. 31 is an enlarged perspective view showing another rotation detecting means according to the eighth embodiment of the present invention.

FIG. 32 is a cross-sectional view of an ultrasonic motor showing a modification of the eighth embodiment of the present invention.

FIG. 33 is a sectional view of an ultrasonic motor showing another modification of the eighth embodiment of the present invention.

FIG. 34 is a partial sectional side view showing a conventional ultrasonic motor.

FIG. 35 is an explanatory diagram illustrating an example of a drive electrode used in a ring-type ultrasonic motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st elastic body 2 1st piezoelectric body 3, 16 vibrating body 4, 17 protrusion 5 moving body 6 bearing 7 rotation axis 8 pressurizing means 10 elastic member 11, 19 support base 12 unevenness 13 2nd elastic body 14 Second piezoelectric body 15, 26, 31 Rotation detecting element 18 Support member 22 Convex-shaped part 23 Curved part 24 Uneven member 101 Conversion circuit 102 Counting circuit 103 Comparison circuit 106 Rotation direction discrimination circuit

Claims (30)

[Claims] A vibrating body having a first piezoelectric body and vibrating by inputting an electric signal, a vibrating body that comes into contact with the vibrating body, and rotation of one of the vibrating body and the vibrating body And an elastic body elastically deformed by the rotation of the vibrating body or the vibrating body in elastic contact with the convex surface of the unevenness, provided on the elastic body, and by the elastic deformation of the elastic body. An ultrasonic motor, comprising: a rotation detecting element having a second piezoelectric body that induces electric charge; and wherein one of the vibrating body and the vibrated body is rotated by vibration of the vibrating body. 2. The ultrasonic motor according to claim 1, wherein the unevenness is formed on a peripheral surface of the rotating shaft. 3. A vibrating member and a vibrating member that rotate have a rotating shaft, and a non-rotating member of the vibrating member and the vibrating member are inserted through the rotating shaft and have a convex-shaped portion at one end in the axial direction. 2. The ultrasonic motor according to claim 1, further comprising a supporting member having the convex shape portion slidably supported by the concave portion of the supporting means. 4. The method of controlling an ultrasonic motor according to claim 1, wherein the electric charge induced in the second piezoelectric body is converted into an electric signal, and the electric signal is converted into a unit. A method of controlling an ultrasonic motor, comprising counting time, and controlling the count value per unit time to be equal to a command value of a speed or a rotation angle. 5. The ultrasonic motor according to claim 1, wherein an interval between adjacent protrusions is uneven. 6. The ultrasonic motor according to claim 1, wherein an interval between adjacent protrusions of the unevenness monotonically increases or decreases within one rotation of the vibrating body or the vibrating body. 7. An ultrasonic motor control method according to claim 1, wherein the electric charge induced in the second piezoelectric body is converted into an electric signal. An ultrasonic motor that converts and measures the time required for one rotation based on the number of electrical signals per rotation of the vibrating or vibrating body, and controls the time per rotation and the command value of speed or rotation angle to be equal. Control method. 8. The method of controlling an ultrasonic motor according to claim 6, wherein the control means has at least N (N> 4) or more projections and depressions. The electric charge induced in the piezoelectric body is converted into an electric signal, the time intervals of at least 4 or more N-1 consecutive electric signals are sequentially compared, and the number of times of increase or decrease of at least 2 or more N-2 is calculated. A method for controlling an ultrasonic motor that detects a rotation direction of a vibrating body or a vibrated body by detection and controls the rotation direction. 9. The ultrasonic motor according to claim 1, wherein the second elastic body has a convex portion or a curved portion at a contact portion that contacts the unevenness. . 10. A gear-shaped uneven member having unevenness is fitted to a rotating member or a rotating shaft of a vibrating member or a vibrating member. An ultrasonic motor according to claim 6 or claim 9. 11. A vibrating body that has a piezoelectric body and vibrates by inputting an electric signal, a vibrating body that comes into contact with the vibrating body, and a row in the rotational direction of one of the vibrating body and the vibrating body. And a rotation detecting element having opposing electrodes at both ends of the slit in non-contact with the unevenness, and one of the vibrating body or the vibrated body is provided by vibration of the vibrating body. Ultrasonic motor that rotates. 12. A vibrating member and a vibrating member that rotate have a rotating shaft, and a non-rotating member of the vibrating member and the vibrating member are inserted into the rotating shaft and have a convex-shaped portion at one end in the axial direction. The ultrasonic motor according to claim 11, further comprising a supporting member having the convex shape portion slidably supported by the concave portion of the supporting means. 13. A vibrating body having a piezoelectric body and vibrating by inputting an electric signal, a vibrating body in contact with the vibrating body, and a vibrating body formed on one surface of the vibrating body and the vibrating body. The conductive film in which the conductor-free portion is arranged in the rotational direction, and the conductive-free portion and the conductive-containing portion of the conductive film alternately pass by rotation of the vibrating body or the vibrated body. A rotation detecting element having a counter electrode opposed to the conductive film in a non-contact manner, wherein the vibrating body or the vibrated body on which the conductive film is formed is formed of a high-resistance material, and the vibration of the vibrating body is An ultrasonic motor in which one of the vibrating member and the vibrating member rotates. 14. A vibrating member and a vibrating member that rotate have a rotating shaft, and a non-rotating member of the vibrating member and the vibrating member are inserted through the rotating shaft and have a convex-shaped portion at one end in the axial direction. 14. The ultrasonic motor according to claim 13, further comprising a supporting member having the convex shape portion slidably supported by the concave portion of the supporting means. 15. An unevenness forming a slit is formed on a side surface of a vibrating body or a vibrating body, a conductive film is formed on the convex surface, and portions where the conductive film exists are connected to each other, and a counter electrode of a rotation detecting element is provided. The ultrasonic motor according to claim 11 or 12, wherein the motor is provided so as to face the convex surface. 16. The ultrasonic motor according to claim 11, wherein the counter electrode of the rotation detecting element is provided so as to face in a diametrical direction of the vibrating body having irregularities or the vibrating body. 17. The method of claim 11, claim 12, or claim 13.
15. The control method of an ultrasonic motor according to claim 14, wherein a change in capacitance induced in the rotation detecting element is converted into an electric signal in response to rotation of the vibrating body or the vibrated body, and the electric signal is converted into a unit. A method for controlling an ultrasonic motor, comprising counting time and controlling the count value of a unit time to be equal to a command value of a speed and a rotation angle. 18. The ultrasonic motor according to claim 11, wherein an interval between the concave and convex slits is not uniform. 19. The ultrasonic motor according to claim 11, wherein an interval between adjacent concave and convex slits monotonically increases or decreases within one rotation. 20. Claim 11, Claim 12, Claim 1
3. The method of controlling an ultrasonic motor according to claim 14, claim 18, or claim 19, wherein the capacitance change induced in the rotation detecting element corresponding to the rotation of the vibrating member or the vibrating member is represented by an electric signal. To measure the time required for one revolution from the number of electrical signals per revolution of the vibrating or vibrating body, and control the time per revolution to be equal to the command value of speed and rotation angle. Characteristic ultrasonic motor control method. 21. The control method of an ultrasonic motor according to claim 19, wherein the control method includes a portion where at least N (N> 4) or more conductive films exist. The capacitance change is converted into an electric signal, and the time intervals of at least 4 or more N-1 consecutive electric signals are sequentially compared, and by detecting at least 2 or more N-2 increase or decrease times, A method for controlling an ultrasonic motor, comprising detecting a rotation direction of a vibrating body or a vibrated body, and controlling the rotation direction. 22. The vibrating body is supported by a supporting means via an elastic member, and the supporting means is pressed against the vibrating body by a pressing means, whereby the vibrating body is moved by the frictional force of the elastic member. The ultrasonic motor according to claim 1, wherein the elastic member is fixed, and the elastic member is an elastic body made of an insulating material including an air layer. 23. The ultrasonic motor according to claim 22, wherein the elastic member is made of a felt material. 24. The elastic member according to claim 1, wherein the thickness of the inner peripheral side of the protrusion is made non-uniform.
The ultrasonic motor according to claim 12, 13 or 14. 25. The ultrasonic motor according to claim 11, wherein a gear-shaped uneven member having unevenness is fitted to a rotating one of the vibrating body and the vibrating body. 26. The ultrasonic motor according to claim 11, wherein the concave portion of the unevenness provided on the vibrating body or the vibrated body is filled with a substance having a different dielectric constant from the vibrating body or the vibrated body. 27. The supporting means according to claim 3, wherein the concave portion has a conical shape, and the convex-shaped portion fitted to the concave portion has a spherical shape.
An ultrasonic motor according to claim 12 or claim 14. 28. The ultrasonic motor according to claim 3, wherein the concave portion of the supporting means has a spheroidal shape, and the convex-shaped portion fitted to the concave portion has a spheroidal shape. 29. A speed distribution, which is a time derivative of a radial vibration displacement distribution excited by the first piezoelectric body to the elastic body, and a pressure distribution applied to the elastic body in response to a desired output torque. A plurality of projections are arranged at positions on the circumference of the elastic body where the product of the applied pressure and the distribution of radially generated force generated as a reaction force on the elastic body is maximum. Claim 1, Claim 2, Claim 3, Claim 11, Claim 1
2. The ultrasonic motor according to claim 13 or claim 14. 30. A method of controlling an ultrasonic motor according to claim 4, claim 7, claim 8, claim 17, claim 20, or claim 21, wherein the amplitude is detected from the first piezoelectric body. A method for controlling a rotation speed and a rotation angle of a vibrating body or a vibrating body based on a signal of the amplitude detection and an output signal of a rotation detecting element.