JPH04281375A - Driver for ultrasonic motor - Google Patents

Abstract

PURPOSE:To reduce in size a circuit configuration and to improve operability by providing drive circuits so as to bring dynamic characteristics of a plurality of stators in coincidence, controlling a plurality of motors and driving one rotor. CONSTITUTION:A drive signal is generated from an oscillator 1 controlled by detectors 4, 5 in a first drive circuit oscillator 1, and amplified by drive signal amplifiers 2, 3 to apply a drive voltage to drive electrodes 11a, 11b of stators 11, 12. The signal from the oscillator 1 is so corrected by an output corrector 7 that the dynamic characteristics of the stators 11, 12 coincide with those of stators 21, 22 in a second drive circuit, amplified by the amplifiers 2, 3 to apply a drive voltage to stator drive electrodes 21a, 21b. A circuit configuration can be reduced in size without necessity of providing oscillators and detectors in a plurality of motors, respectively, and the number of regulating steps is reduced to improve operability. Since the signal is so corrected that the dynamic characteristics of the stators coincide, drive efficiency and control accuracy of the motor are 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 drive device.

0002

[Prior Art] Conventionally, the phase difference between the drive voltage waveform applied to the drive electrode of an ultrasonic motor and the voltage waveform of a monitor electrode that generates a frequency voltage corresponding to the vibration of the elastic body of the ultrasonic motor has been stabilized. There is known an ultrasonic motor drive device that controls the drive frequency to a predetermined value that provides the desired drive state (see, for example, Japanese Patent Laid-Open No. 61-251490).

FIG. 9 shows the configuration of this type of ultrasonic motor driving device. A drive signal with a frequency f1 generated by the oscillation unit 1 is converted into two drive signals having a phase difference of π/2 by a phase shifter 2, and each of these drive signals is separately amplified by an output amplification unit 3. and is applied to the drive electrodes 11a and 11b of the piezoelectric body 11 of the ultrasonic motor 10.

When the piezoelectric body 11 of the ultrasonic motor 10 is excited by these drive signals, progressive vibration waves are generated on the drive surface of the elastic body 12 joined to the piezoelectric body 11. The mover 1 is brought into pressure contact with the driving surface of the elastic body 12.
3 is driven by this progressive vibration wave to rotate.

The output detection unit 4 detects the phase difference between the frequency voltage (hereinafter referred to as monitor voltage) generated at the monitor electrode 11c in response to the vibration of the elastic body 12 and the drive voltage applied to the drive electrodes 11a and 11b. is detected, and the output control section 5 controls the oscillation section 1 so that this phase difference becomes a predetermined value that provides a stable driving state. That is, the output detection section 4 and the output control section 5 constitute a feedback circuit of the ultrasonic motor drive device.

By the way, by using a plurality of ultrasonic motors, one
When driving two rotating shafts or rotating cylinders, the dynamic characteristics of each ultrasonic motor in response to the drive signal are different, so it has been proposed to provide an independent drive device for each ultrasonic motor (for example, (Refer to Japanese Patent Application Laid-Open No. 1-227669).

[0007]

However, if an ultrasonic motor drive device having a feedback circuit shown in FIG. 9 is used for each of a plurality of ultrasonic motors that drive one rotating shaft or rotating cylinder, the circuit In addition to the large scale of the device, it is necessary to make adjustments for each ultrasonic motor, resulting in poor operability.

An object of the present invention is to control a plurality of ultrasonic motors to drive one rotary body, achieve miniaturization with a minimum circuit configuration, reduce adjustment man-hours, and improve operability. An object of the present invention is to provide a driving device for a sonic motor.

[0009]

[Means for Solving the Problems] The present invention will be explained in conjunction with FIG. 1 showing the configuration of an embodiment. at least two stators (11,
12), (21, 22) and at least one mover 13, 23 driven by progressive vibration waves, an oscillating unit 1 that generates a drive signal; Drive that amplifies the drive signal and applies a drive voltage to the drive electrodes 11a, 11b of any one of the stators 11, 12 among at least two stators (11, 12), (21, 22). Signal amplification sections 2 and 3 and ultrasonic motor 1
a first drive circuit consisting of detection units 4 and 5 that control the oscillation unit 1 so as to detect an output of 0 and obtain a stable drive state; a stator 11 driven by the first drive circuit; 12
a drive signal correction unit 7 (7A) that corrects the drive signal from the oscillation unit 1 so that the dynamic characteristics of the stators match those of the other stators 21 and 22; 1st
and a second drive circuit comprising drive signal amplification units 2 and 3 that apply drive voltages to drive electrodes 21a and 21b of stators 21 and 22 other than stators 11 and 12 driven by the drive circuit. This achieves the above objective. Further, in the ultrasonic motor of claim 2, there are a plurality of sets 10, 20 of ultrasonic motors in which one moving element is provided for one stator, and each moving element 13, 23 is connected to the same rotating body 6. directly connected via. Further, in the ultrasonic motor according to a third aspect of the present invention, stators are arranged on both sides of the movable element, and the ultrasonic motor includes a plurality of stators and a plurality of movable elements.

0010

According to claim 1, in the first drive circuit, the oscillation section 1 generates a drive signal, and the drive signal amplification sections 2 and 3 amplify the drive signal from the oscillation section 1 to generate at least two A driving voltage is applied to the driving electrodes 11a, 11b of any one of the stators 11, 12. The detection units 4 and 5 detect the output of the ultrasonic motor 10 and control the oscillation unit 1 so as to obtain a stable driving state. On the other hand, the second
In the drive circuit shown in FIG. Part 1
The drive signal amplifiers 2 and 3 amplify the corrected drive signals to drive the stators 21 and 22 other than the stators 11 and 12 driven by the first drive circuit. A driving voltage is applied to the electrodes 21a and 21b. Also, claim 2
The ultrasonic motor drive device of
There are multiple sets of ultrasonic motors each equipped with a number of movers.
Each moving element drives ultrasonic motors 10 and 20 that are directly connected via the same rotating body 6. Further, in the ultrasonic motor driving device according to the third aspect of the present invention, stators are arranged on both sides of the movable element, and an ultrasonic motor including a plurality of stators and a plurality of movable elements is driven.

[0011] In the section of means and effects for solving the above-mentioned problems that describes the structure of the present invention, figures of embodiments are used in order to make the present invention easier to understand. It is not limited to.

0012

Embodiments - First Embodiment - FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. Note that devices similar to those of the conventional device shown in FIG. 9 are given the same reference numerals, and the explanation will focus on the differences. 20 is
The ultrasonic motor has the same configuration as the ultrasonic motor 10, and its mover 23 is the same as the mover 13 of the ultrasonic motor 10.
and is directly connected via the rotating body 6. In addition, the ultrasonic motor 10
, 20 are respectively shown in FIG. 2(a) with respect to the frequency of the driving voltage.
), it has rotational speed characteristics as shown in Fig. 2(b).

As the drive circuit for the ultrasonic motor 10, a circuit similar to the drive circuit shown in FIG. 9 is used. On the other hand, the drive circuit of the ultrasonic motor 20 includes an output correction section 7 that corrects the frequency of the drive signal from the oscillation section 1, and converts the corrected drive signal into two drive signals having phases different from each other by π/2. and an output amplification section 3 that amplifies the signals and applies them to the drive electrodes 21a and 21b of the ultrasonic motor 20.

FIG. 3 shows the configuration of the output correction section 7. In the figure, 71 is a differentiation circuit that performs differential operation on the drive signal;
72 is a rectifier circuit that rectifies the drive signal after the differential operation;
3 is a constant positive voltage + supplied from a constant voltage source (not shown)
This is a switch that switches between Vd and a constant negative voltage -Vd. 74 is a non-inverting type amplifier circuit to be described later, which amplifies the input voltage selected by the switch 73 and adjusts the voltage ±△.
Outputs V. Note that when the positive constant voltage +Vd is selected by the switch 73, the amplifier circuit 74 outputs the positive voltage +△
When the constant negative voltage -Vd is selected, the amplifier circuit 74 outputs a negative voltage -ΔV. Reference numeral 75 denotes an adder circuit that adds the output voltage V of the rectifier circuit 72 and the output voltage ±ΔV of the amplifier circuit 74. Furthermore, 76 is a voltage controlled oscillator (hereinafter referred to as VCO), which outputs a frequency voltage having a frequency proportional to the input voltage, as shown in FIG.

FIG. 5 shows a detailed circuit diagram of the amplifier circuit 74. The amplifier circuit 74 includes a non-inverting amplifier AMP1 and a resistor R.
s and Rf, and its output voltage ΔV is calculated by the following equation. △V=(+Vd or -Vd)×(1+Rf/
Rs) (1) That is, by adjusting the resistance value of the resistor Rf, the output voltage ΔV can be changed.

FIG. 6 shows the voltage waveforms of each part of the circuit of the output correction section 7, (a) shows the drive signal waveform of the oscillation section 1, and (
b) shows the waveform of the output voltage fD of the differentiating circuit 71, and (c
) shows the waveform of the output voltage V of the rectifier circuit 72, (d) shows the waveform of the output voltage V+ΔV of the adder circuit 75, and (e) shows the waveform of the output voltage V+ΔV of the adder circuit 75.
shows the output voltage waveform of the VCO 76. The operation of the output correction section 7 will be explained with reference to these figures. Drive signal A・sin(2π・f1・
t) is input to the differentiation circuit 71 via the terminal IN of the output correction section 7. The differentiating circuit 71 performs a differential operation on the input drive signal to obtain a signal fD=2π·f1 shown in FIG. 6(b).
・Output A・cos(2π・f1・t). Note that the amplitude of this signal fD increases as the frequency f1 of the drive signal increases. Next, the rectifier circuit 72 converts the differentiated drive signal into a DC voltage V shown in FIG. 6(c) and outputs it to the adder circuit 75. On the other hand, the amplifier circuit 74
Amplify the constant positive voltage +Vd selected by
ΔV is output to the adder circuit 75. The adder circuit 75 adds these voltages V and +ΔV and outputs an output voltage V+ΔV shown in FIG. 6(d) to the VCO 76. As shown in FIG. 4, the VCO 76 outputs a square wave frequency voltage (FIG. 6(e)) with a frequency f1+Δf proportional to the input voltage V+ΔV, and further outputs a square wave frequency voltage (FIG. 6(e)) with a frequency f1+ after passing through a waveform shaping circuit (not shown). △
A sine wave voltage of f is output to the terminal OUT. That is, the drive signal from the oscillator 1 has a signal frequency of f1+△f
It is corrected to Conversely, when -Vd is selected by switch 73, amplifier circuit 74 outputs -ΔV, and adder circuit 75 outputs voltage V-ΔV. As a result, the frequency of the drive signal is corrected to f1-Δf. Note that the switch 73
The output voltage ±ΔV of the amplifier circuit 74 can also be changed by changing the positive and negative constant voltages ±Vd that are switched by.

In this output correction section 7, the amount of correction is
Since it is set separately from the drive signal input from the drive signal, it is not affected by changes in the voltage and frequency of the drive signal.

Next, the operation of the apparatus of the first embodiment will be explained. First, in the drive circuit of the ultrasonic motor 10, the oscillation section 1
A drive signal with a frequency f1 generated from
They are amplified separately by the output amplifying section 3 and applied to the drive electrodes 11a and 11b of the ultrasonic motor 10. As a result, progressive vibration waves are generated on the driving surface of the elastic body 12 of the ultrasonic motor 10, and the moving element 13 is driven, as shown in FIG.
As shown in (a), it rotates at a rotational speed n1. The monitor voltage generated at the monitor electrode 11c of the ultrasonic motor 10 and the drive voltage at the drive electrode 11a are detected by the output detection section 4, and the phase difference between these voltage waveforms is calculated. This phase difference is input to the output control section 5, and the frequency f1 of the oscillation section 1 is corrected so that it becomes a predetermined phase difference that provides a stable driving state of the ultrasonic motor 10. by this,
The oscillator 1 generates a drive signal of an optimal frequency for the ultrasonic motor 10.

Note that, as shown in, for example, Japanese Patent Laid-Open No. 63-206171, a pulse generator is provided on the rotating body 6, and the output detecting section 4 counts the number of pulses to detect the number of pulses in the moving element.
The output controller 5 detects the rotational speed of the ultrasonic motor 10.
The oscillator 1 may be controlled so that the driving state is stable.

The drive signal of the oscillator 1, which has been corrected by detecting the output of the ultrasonic motor 10 and is corrected so as to obtain a stable drive state, is also supplied to the output corrector 7 of the drive circuit of the ultrasonic motor 20. The output correction unit 7, as shown in FIG. 2(a),
The drive signal is corrected so that the rotational speed characteristics of the ultrasonic motor 20 match those of the ultrasonic motor 10. That is,
The frequency of the drive signal output from the output correction section 7 is f1-
The switch 73 shown in FIG. 3 selects a negative constant voltage -Vd so that Δf, and the resistor Rf of the amplifier circuit 74
Adjust. After that, the output drive signal of the output correction section 7 is
The phase shifter 2 converts the signal into two drive signals having a phase difference of π/2, and the output amplifier 3 amplifies them separately and applies them to the drive electrodes 21a and 21b of the ultrasonic motor 20. . As a result, as shown in FIG. 2(a), the dynamic characteristics of both ultrasonic motors 10 and 20 match, and the ultrasonic motor 2
0 is driven with a driving voltage of frequency f2=f1-△f,
The moving element 23 is driven and controlled to have the same rotational speed n1 as the moving element 13 of the ultrasonic motor 10.

In the above embodiment, the output correction section 7 corrects the frequency of the drive signal of the oscillation section 1 and controls the ultrasonic motor 20 to match the rotational speed of the ultrasonic motor 10. It is known that the rotational speed in the driving frequency range of the ultrasonic motor 10 is proportional to its driving voltage, and the driving voltage of the ultrasonic motor 20 may be corrected and controlled to match the rotational speed of the ultrasonic motor 10. FIG. 7 shows a circuit of an output correction section 7A that corrects only the voltage of the drive signal while keeping the frequency of the drive signal generated by the oscillation section 1 as f1. This output correction section 7A is an inverting amplifier circuit composed of an amplifier AMP2 and resistors Rs and Rf,
The output Vout of the oscillation unit 1 with respect to the drive signal input Vin is expressed by the following equation. Vout=Vin・(-Rf/Rs)
(2) That is, by adjusting the resistor Rf, the output voltage Vout of the output correction section 7A, that is, the voltage of the drive signal is corrected. As described above, the corrected drive signal is applied to the drive electrodes 21a and 21b of the ultrasonic motor 20 via the phase shifter 2 and the output amplification unit 3 of the drive circuit of the ultrasonic motor 20.
is applied to As a result, as shown in FIG. 2(b), the dynamic characteristics of both ultrasonic motors 10 and 20 match, and the ultrasonic motor 20 has a rotational speed n2 before correction at the drive frequency f1.
From there, the rotation speed is increased to a rotational speed n1 equal to that of the ultrasonic motor 10, and the drive is controlled.

Since this output correction section 7A is composed only of an operational amplifier circuit, it does not require a complicated circuit configuration like the output correction section 7 shown in FIG. With this configuration, an optimal drive signal for the ultrasonic motor 20 can be generated. Note that the method of correcting the frequency or voltage of the drive signal in the output correction units 7, 7A is not limited to the above embodiment, and may be a method of controlling the drive so that the dynamic characteristics of the ultrasonic motor 20 match those of the ultrasonic motor 10. That's fine.

In this way, for the two sets of ultrasonic motors 10 and 20 having a pair of stators and movers, the oscillating section 1 generates drive signals, and the drive signals are separated by π/2 from each other. A phase shifter 2 and an output amplifier 3 convert the signals into two drive signals having different phases, amplify them, and apply a drive voltage to the drive electrodes 11a and 11b of the stator of one of the ultrasonic motors 10; A first drive circuit includes an output detection section 4 and an output control section 5 that detect the output of the sonic motor 10 and control the oscillation section 1 so as to obtain a stable driving state, and a rotational speed of the ultrasonic motor 20. An output correction unit 7 (7A) that corrects the drive signal from the oscillation unit 1 so as to match the rotational speed of the ultrasonic motor 10, and two drive units that output the corrected drive signals with a phase difference of π/2 from each other. Since a second drive circuit consisting of an output amplifying section 3 that converts the signals into signals, amplifies them, and applies them to the drive electrodes 21a and 21b of the stator of the ultrasonic motor 20 is provided, each ultrasonic wave The oscillating unit 1 is separately provided for each of the motors 10 and 20.
There is no need to provide a feedback circuit consisting of the output detection section 4 and the output control section 5, the circuit configuration becomes small-scale, the device is miniaturized, the number of adjustment steps is reduced, and the operability is improved.

Further, the oscillation unit 1 generates an optimal drive signal for obtaining a stable driving state for the ultrasonic motor 10, and the output correction unit 7 (7A) adjusts the rotational speed of the ultrasonic motor 20. Since the drive signal of the oscillator 1 is corrected so that the rotational speed of the ultrasonic motor 10 matches the rotational speed of the ultrasonic motor 10, even if the ultrasonic motors 10 and 20 have different control characteristics, their dynamic characteristics almost match. In addition to improving drive efficiency,
The control accuracy of the rotating body 6 driven by both the ultrasonic motors 10 and 20 is improved.

In the first embodiment, two sets of ultrasonic motors 10 and 20 each having a pair of stators and a mover were explained as an example. The present invention can also be applied to an ultrasonic motor that drives stators by bringing them into pressure contact with each other, and similar effects can be obtained.

-Second Embodiment- Next, a second embodiment will be described in which three sets of ultrasonic motors each consisting of a pair of stators and a movable element are driven. FIG. 8 is a block diagram showing the configuration of this second embodiment. In addition,
Devices similar to those in FIG. 1 showing the configuration of the first embodiment are given the same reference numerals, and the explanation will focus on the differences. The movers 13, 23, 33 of each ultrasonic motor 10, 20, 30 are directly connected to the same rotating body 6. Ultrasonic motor 10, 20
The drive circuit for the ultrasonic motor 30 is similar to the circuit shown in FIG.
This is similar to the drive circuit of That is, the ultrasonic motor 30
The output correction section 7 (7A) is connected to the oscillation section 1 and is supplied with a drive signal from the oscillation section 1.

The drive signal generated by the oscillator 1 is supplied to the phase shifter 2 of the ultrasonic motor 10 and the output corrector 7 (7A) of the ultrasonic motor 20 and the ultrasonic motor 30. In the drive circuit of the ultrasonic motor 10, as described above, a drive signal is converted into two drive signals having a phase difference of π/2 in the phase shifter 2, and these are then separately converted in the output amplification part 3. The drive electrode 1 of the ultrasonic motor 10 is amplified.
1a and 11b. Further, in the drive circuit of the ultrasonic motor 20, as described above, the output correction section 7 (7A)
The drive signal is corrected so that the drive speed of the ultrasonic motor 20 matches the drive speed of the ultrasonic motor 10, and the corrected drive signals are transferred to the phase shifter 2, which has a phase difference of π/2 from each other.
The output amplifier 3
The signals are amplified separately and applied to the drive electrodes 21a and 21b of the ultrasonic motor 20. Furthermore, in the drive circuit of the ultrasonic motor 30, similarly to the drive circuit of the ultrasonic motor 20, the output correction unit 7 (7A) adjusts the drive speed of the ultrasonic motor 30 to match the drive speed of the ultrasonic motor 10. The drive signal is corrected, and the corrected drive signal is converted into two drive signals having phases different from each other by π/2 in a phase shifter 2,
Further, they are each amplified separately by the output amplifying section 3 and applied to the drive electrodes 31a and 31b of the ultrasonic motor 30.

In this way, three ultrasonic motors 10, 2
Even when driving the same rotary body 6 at 0.0, 30, each ultrasonic motor 10, 20, 30 has a separate oscillation section 1, an output detection section 4, and an output control section 5 that constitute a feedback circuit. There is no need to provide a circuit, the circuit configuration becomes small-scale, the device becomes smaller, and the number of adjustment steps is reduced, improving operability.

Further, the oscillation unit 1 generates an optimal drive signal for the ultrasonic motor 10 to obtain a stable driving state, and the output correction unit 7 (7A) of the drive circuit of the ultrasonic motor 20 generates an optimal drive signal. , corrects the drive signal of the oscillation unit 1 so that the rotation speed of the ultrasonic motor 20 matches the rotation speed of the ultrasonic motor 10, and similarly, the output correction unit 7 (7A) of the drive circuit of the ultrasonic motor 30. Then, since the drive signal of the oscillator 1 is corrected so that the rotational speed of the ultrasonic motor 30 matches the rotational speed of the ultrasonic motor 10, the driving signal of the oscillator 1 is corrected so that the rotational speed of the ultrasonic motor 30 matches that of the ultrasonic motor 10. Sonic motor 10, 20, 30
However, their dynamic characteristics almost match, improving drive efficiency and control accuracy.

[0030]Although the above embodiments have been explained using drive devices for two and three ultrasonic motors as examples, the present invention can also be applied to four or more ultrasonic motors. , the same effect as described above can be obtained.

Furthermore, in the above embodiment, the ultrasonic motor 10
Although the oscillation section 1, the output detection section 4, and the output control section 5 are provided in the embodiment, they may be provided in the ultrasonic motor 20 or the ultrasonic motor 30.

In the configuration of the above embodiment, the piezoelectric body 11
and the elastic body 12, the piezoelectric body 21 and the elastic body 22, the piezoelectric body 31 and the elastic body 32 serve as the stator, and the movers 13, 23, 3 respectively.
3 is a moving element, oscillation part 1 is an oscillation part, phase shift part 2 and output amplification part 3 are a drive signal amplification part, output detection part 4 and output control part 5 are a detection part, output correction part 7 or 7A constitute a drive signal correction section.

[0033]

Effects of the Invention As described above, according to the invention of claim 1, an oscillating section that generates a drive signal for an ultrasonic motor consisting of at least two stators and at least one mover is provided. , a drive signal amplification unit that amplifies the drive signal and applies a drive voltage to the drive electrode of any one of the at least two stators, and a drive signal amplification unit that detects the output of the ultrasonic motor to ensure stable drive. a first drive circuit comprising a detection section that controls the oscillation section so as to obtain the desired state; and a first drive circuit that controls the oscillation section so that the dynamic characteristics of the stator driven by the first drive circuit match those of other stators. , a drive signal correction unit that corrects the drive signal from the oscillation unit, and a drive signal that amplifies the corrected drive signal and applies a drive voltage to the drive electrodes of the stators other than the stator driven by the first drive circuit. Since a second drive circuit consisting of a drive signal amplification section is provided, there is no need to separately provide an oscillation section and a detection section for each ultrasonic motor, and the circuit configuration is miniaturized. , the number of adjustment steps is reduced and operability is improved. In addition, the drive signal correction section corrects the drive signal of the oscillation section so that the dynamic characteristics of each stator match, so even if the ultrasonic motors have different dynamic characteristics, their dynamic characteristics will almost match. , driving efficiency and control accuracy are improved. Further, according to the invention of claim 2, even for a plurality of sets of ultrasonic motors in which one stator is provided with one mover, the oscillation unit and the detection unit are separately provided for each ultrasonic motor. There is no need to provide a section, and the same effect as above can be obtained. Furthermore, according to the invention of claim 3, stators are arranged on both sides of the mover, and even for an ultrasonic motor consisting of a plurality of stators and a plurality of movers, each stator is separately provided. There is no need to provide an oscillating section and a detecting section, and the same effects as above can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a first embodiment.

FIG. 2 is a diagram showing the rotational speed characteristics of the ultrasonic motor with respect to the frequency of the drive voltage; (a) shows the drive frequency of one of the two ultrasonic motors corrected to drive both ultrasonic motors; A drive signal correction method for matching speed characteristics is shown, (b
) shows a drive signal correction method in which the drive voltage of one of two ultrasonic motors is corrected to match the drive speed characteristics of both ultrasonic motors.

FIG. 3 is a block diagram showing the configuration of an output correction section.

FIG. 4 is a diagram showing output frequency characteristics with respect to input voltage of a voltage controlled oscillator (VCO).

FIG. 5 is a detailed circuit diagram of a non-inverting amplifier circuit.

FIG. 6 is a diagram showing voltage waveforms of various parts of the circuit of the output correction section,
(a) shows the drive signal waveform of the oscillator, (b) shows the waveform of the output voltage fD of the differentiating circuit, (c) shows the waveform of the output voltage V of the rectifier circuit, and (d) shows the waveform of the output voltage V of the adding circuit. Output voltage V
The waveform of +△V is shown, and (e) is the voltage controlled oscillator (VCO).
) shows the output voltage waveform.

FIG. 7 is a circuit diagram of another output correction section.

FIG. 8 is a block diagram showing the configuration of a second embodiment.

FIG. 9 is a block diagram showing a conventional ultrasonic motor drive device.

[Explanation of symbols]

1 Oscillation section 2 Phase shift section 3 Output amplification section 4 Output detection section 5 Output control section 6 Rotating body 7, 7A Output correction section 10, 20, 30 Ultrasonic motor 11, 21, 31 Piezoelectric body 11a, 11b, 21a, 21b , 31a, 31b
Drive electrode 11c Monitor electrodes 12, 22, 32 Elastic bodies 13, 23, 33 Mover 71 Differentiator circuit 72 Rectifier circuit 73 Switch 74 Amplifier circuit 75 Adder circuit 76 Voltage controlled oscillator (VCO) AMP1, AMP2 Amplifier Rs, Rf Resistor

Claims (3)

[Claims] 1. An ultrasonic motor comprising at least two stators that generate progressive vibration waves in an elastic body by excitation of a piezoelectric body, and at least one mover that is driven by the progressive vibration waves. The drive device includes an oscillator that generates a drive signal, and a drive signal that amplifies the drive signal and applies a drive voltage to a drive electrode of any one of the at least two stators. a first drive circuit including an amplifier section and a detection section that detects the output of the ultrasonic motor and controls the oscillation section so as to obtain a stable driving state; and a drive circuit driven by the first drive circuit. a drive signal correction unit that corrects the drive signal from the oscillation unit so that the dynamic characteristics of the stator match the dynamic characteristics of other stators; and a drive signal correction unit that amplifies the corrected drive signal and An ultrasonic motor drive device comprising: a second drive circuit including a drive signal amplification section that applies a drive voltage to drive electrodes of stators other than the stator driven by the drive circuit. 2. The ultrasonic motor driving device according to claim 1, wherein the ultrasonic motor includes a plurality of sets of ultrasonic motors each having one mover for one stator. . An ultrasonic motor driving device, wherein each of the movable elements is directly connected via the same rotating body. 3. The ultrasonic motor drive device according to claim 1, wherein the ultrasonic motor has a stator disposed on both sides of a movable element, and the ultrasonic motor comprises a plurality of stators and a plurality of movable elements. An ultrasonic motor drive device characterized by being a motor.