JP2019080490A - Vibration type actuator, lens barrel, camera, and control method - Google Patents

Abstract

[Problem] To provide a vibration type actuator capable of reducing the decrease in drive efficiency when multiple vibrators are driven simultaneously. [Solution] A vibration type actuator having a first vibrator, a second vibrator, a friction member with which the first vibrator and the second vibrator are in contact in common, and a drive control means for controlling the drive of the first vibrator and the second vibrator, in which the first vibrator and the second vibrator are vibrated to cause relative movement between the first vibrator and the second vibrator and the friction member, and the drive control means controls the drive of the first vibrator and the second vibrator so that the difference between the drive frequency of the first vibrator and the drive frequency of the second vibrator does not match the natural frequency of the friction member. [Selected Figure] Figure 1

Description

  The present invention relates to a vibration type actuator, a lens barrel, a camera and a control method.

  An ultrasonic motor, which is one of vibration type actuators, is widely adopted as a drive source for cameras and lenses. Ultrasonic motors have features such as high torque output, high positioning accuracy, and quietness. In recent years, even in a multi-group zoom configuration, a compact device having a relatively simple structure is desired, and a configuration in which a friction member is shared by a plurality of ultrasonic motors is considered.

  In a normal ultrasonic motor, when driving a plurality of ultrasonic motors independently at the same time, a difference in driving frequency causes a beat phenomenon to lower the driving efficiency. Patent Document 1 discloses a technique for reducing the beat phenomenon by matching the drive frequencies of a plurality of ultrasonic motors.

JP, 2008-160913, A

  In the ultrasonic motor disclosed in Patent Document 1, the drive frequencies input to the plurality of ultrasonic transducers coincide with each other, and therefore, the plurality of ultrasonic transducers can not be independently driven at an arbitrary speed.

  An object of the present invention is to provide a vibration-type actuator capable of reducing a decrease in drive efficiency when simultaneously driving a plurality of vibrators.

  The vibration-type actuator according to one embodiment of the present invention includes a first vibrator, a second vibrator, a friction member in common contact with the first vibrator and the second vibrator, and the friction member. Driving control means for performing driving control of the first vibrator and the second vibrator, and vibrating the first vibrator and the second vibrator to perform the first vibration The vibration type actuator in which the element and the second vibrator and the friction member move relative to each other, wherein the drive control means has a driving frequency of the first vibrator and a driving frequency of the second vibrator. The drive control of the first vibrator and the second vibrator is performed so that the difference does not coincide with the natural frequency of the friction member.

  According to the present invention, it is possible to reduce the decrease in drive efficiency when simultaneously driving a plurality of vibrators.

It is a figure showing a vibration type actuator. It is an exploded perspective view of an ultrasonic motor. It is a figure which shows the main structure parts of an ultrasonic motor. It is a flowchart explaining control processing of an ultrasonic wave motor. It is a figure which shows the relationship between the drive frequency and speed of an ultrasonic transducer. FIG. 7 is a view showing a piezoelectric element applied in Example 2; It is a drive signal input to the electrode of the piezoelectric element which comprises an ultrasonic transducer | vibrator. It is a figure which shows the relationship between the drive frequency f of an ultrasonic transducer, and the speed v.

Example 1
Hereinafter, the present embodiment will be described in detail based on the attached drawings. In the following description, an ultrasonic motor unitized as a vibration-type actuator for driving a lens barrel or the like of a digital camera will be described as an example. However, the use application of the present invention is not limited to the ultrasonic motor.

FIG. 1 is a view showing a vibration-type actuator of a first embodiment.
The vibration-type actuator shown in FIG. 1 functions as one ultrasonic motor including a first ultrasonic motor 101a and a second ultrasonic motor 101b. FIG. 1A is a cross-sectional view of a vibration-type actuator. In FIG. 1A, a first ultrasonic motor 101a and a second ultrasonic motor 101b are shown. FIG. 1 (B) is a partially enlarged view of the first ultrasonic motor 101a. FIG. 2 is an exploded perspective view of the ultrasonic motor.

  In the present embodiment, the first ultrasonic motor 101a and the second ultrasonic motor 101b have the same configuration, and in order to simplify the description, the first ultrasonic motor is representatively shown in FIG. 1 (B). Only the portion 101a is shown. The vibration type actuator may have ultrasonic motors of different configurations.

  Further, also in FIG. 2, only the first ultrasonic motor 101 a portion is in a disassembled state, and the description of the common portions will be omitted. However, since the ultrasonic transducers need to be distinguished, the ultrasonic transducers mounted on the first ultrasonic motor 101a are referred to as the first ultrasonic transducers 115a. Also, an ultrasonic transducer mounted on the second ultrasonic motor 101b is referred to as a second ultrasonic transducer 115b.

  The ultrasonic transducer 115a has a diaphragm 104a and a piezoelectric element 105a. The diaphragm 104a and the piezoelectric element 105a are fixed by a known adhesive or the like, and the piezoelectric element 105a excites ultrasonic vibration by applying a voltage.

  The pressing mechanism holding member 110a is provided with a holding hole for receiving the spring guide 108a. One end of the spring 109a is in contact with the spring guide 108a. The other end of the spring 109a is in contact with the pressing mechanism holding member 110a. The pressing mechanism holding member 110a also has a holding hole for receiving the elastic member 107a. The spring 109a is sandwiched between the pressing mechanism holding member 110a and the spring guide 108a. Thus, the spring 109a applies a pressing force in the Z-axis direction. An elastic member 107a is disposed between the piezoelectric element 105a and the spring 109a. The elastic member 107a prevents direct contact between the pressing portion and the piezoelectric element 105a, thereby preventing damage to the piezoelectric element 105a.

  The diaphragm 104a includes a contact portion 116a. The contact portion 116 a is in contact with the friction member 102 in a state of being pressed by the pressing force of the spring 109 a. In a state where the vibration plate 104a and the piezoelectric element 105a are bonded to each other, the piezoelectric element 105a excites ultrasonic vibration to generate substantially elliptical motion in the contact portion 116a of the vibration plate 104a. At this time, two vibration modes are generated in the ultrasonic transducer 115a.

  The ultrasonic transducer 115a and the transducer holding member 106a are fixed by a known adhesive or the like, but the method is not limited as long as they are fixed. Further, the vibrator holding member 106a is fitted to the pressing mechanism holding member 110a so as not to inhibit the power of the elliptical motion excited by the ultrasonic vibration.

  The pressing mechanism holding member 110a is provided with two V-groove moving side guides, and three spherical rolling members 111a, 112a, 113a are fitted in each. On the other hand, in the cover plate 112 as the fixing portion, two V-groove fixed side guiding portions having a predetermined length in the X-axis direction are provided. The rolling members 111a, 112a, and 113a are held by the moving side guide portion of the pressing mechanism holding member 110a and the fixed side guide portion of the cover plate 112. Although the movable side guide portion and the fixed side guide portion described above are provided with movable range restricting portions for restricting the movable range of the rolling members 111a, 112a, 113a, in the description of this embodiment, I omit it.

  The ultrasonic motor shown in FIG. 2 further includes a ground plate 103. The ground plate 103 and the cover plate 112 are fixed by screws (not shown) or the like from the upper side in the Z-axis direction, but the method is not limited as long as they are fixed. Further, on the bottom surface side of the main plate 103, the friction member 102 is fixed by a screw or the like (not shown) from the lower side of the Z-axis, but the method is not limited as long as it is fixed.

  Next, the pressing force generated in the pressing unit will be described. The pressing force of the spring 109 a is an urging force that presses the ultrasonic transducer 115 a against the friction member 102 via the elastic member 107 a. The contact portion 116 a of the diaphragm 104 a contacts the friction member 102 in a pressurized state. On the other hand, the pressing reaction force from the friction member 102 is received by the cover plate 112 via the moving part 120a and the rolling members 111a, 112a, 113a. When a drive voltage is applied to the piezoelectric element 105 a in this pressure contact state, the elliptical motion generated in the ultrasonic transducer 115 a is efficiently transmitted to the friction member 102. As a result, the moving unit 120a can advance and retract in the X-axis direction.

  In the present embodiment, the moving unit 120a is configured by the ultrasonic transducer 115a, the transducer holding member 106a, the elastic member 107a, the spring guide 108a, the spring 109a, and the pressing mechanism holding member 110a. Further, a base portion is formed by the cover plate 112, the base plate 103, and the friction member 102.

  The first ultrasonic motor 101 a and the second ultrasonic motor 101 b share the friction member 102 as shown in FIGS. 1 and 2. The first ultrasonic motor 101a and the second ultrasonic motor 101b each include a frequency calculation circuit 134 and a drive control method determination circuit 135 which will be described later, but are omitted in this figure.

  Although in FIG. 1 the first ultrasonic motor 101a and the second ultrasonic motor 101b share the cover plate 112 as the fixing portion and are arranged in series, the present invention is not limited to this configuration. For example, it may be in a form arranged in parallel.

  In the configuration shown in FIG. 1, the friction member has a contact surface with which the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b make frictional contact in common. A beat phenomenon occurs due to the difference between the respective drive frequencies input to the first ultrasonic transducer 115a and the second ultrasonic transducer 115b. When the above difference is close to the natural frequency of the friction member 102 shared, the resonance is largely generated, and the driving efficiency of the ultrasonic motor is lowered. In this embodiment, in order to prevent the beat phenomenon, the difference between the drive frequencies input to the first ultrasonic transducer 115a and the second ultrasonic transducer 115b is calculated, and the drive control method is calculated from the result. decide.

FIG. 3 is a diagram showing the main components of the ultrasonic motor.
In this embodiment, the ultrasonic motor includes a first position encoder 131a for acquiring position information of the first ultrasonic transducer 115a, and a second position encoder for acquiring position information of the second ultrasonic transducer 115b. And 131b.

  Also, the ultrasonic motor includes a position deviation calculation circuit 132 that calculates position deviation by comparing the position information output from the first position encoder 131a and the second position encoder 131b with the respective target positions. There is. Furthermore, the ultrasonic motor includes a drive frequency setting circuit 133 that sets the drive frequency of the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b. The ultrasonic motor also includes a frequency calculation circuit 134 that calculates the difference between the drive frequencies set by the drive frequency setting circuit 133. The ultrasonic motor also outputs a drive signal to the drive method determined by the drive control method determination circuit 135 which determines the drive control method based on the calculation result of the frequency calculation circuit 134 and the drive control method determination circuit 135. And a signal output circuit 136.

  The first position encoder 131 a outputs the position information of the first ultrasonic transducer 115 a to the position deviation calculation circuit 132. Further, the second position encoder 131 b outputs the position information of the second ultrasonic transducer 115 b to the position deviation calculation circuit 132. The position deviation calculation circuit 132 compares the position information of the first ultrasonic transducer 115a and the position information of the second ultrasonic transducer 115b with the respective target positions to obtain the first ultrasonic transducer 115a and the second ultrasonic transducer 115a. The positional deviation of each of the ultrasonic transducers 115 b is output to the drive frequency setting circuit 133.

  The drive frequency setting circuit 133 sets the drive frequency to be output to the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b from the above-described positional deviation. For example, when the position deviation is large, the drive frequency setting circuit 133 sets the drive frequency to increase the speed. The frequency calculation circuit 134 calculates the difference between the drive frequencies of the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b set by the drive frequency setting circuit 133.

Here, assuming that the driving frequencies of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b are f1 and f2, respectively, and the difference between f1 and f2 is df, the following calculation is performed.
df = | f1-f2 |
Although the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b are illustrated, the present invention is not limited to this, and when there are many ultrasonic transducers, the respective ultrasonic transducers may be used. The difference in drive frequency may be determined.

  The drive control method determination circuit 135 compares the difference between the drive frequencies of the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b with a predetermined threshold in consideration of the natural frequency of the friction member 102. Then, based on the comparison result, the drive control method determination circuit 135 determines the drive method of the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b. This threshold value is preset to, for example, a value near the natural frequency of the friction member 102. When the difference in drive frequency is close to the natural frequency, a beat phenomenon occurs.

  The drive control method determination circuit 135 changes the duty ratio of the second ultrasonic transducer, for example, when the difference in drive frequency is equal to or greater than the threshold. Then, the drive control method determination circuit 135 sets the drive frequency at which the beat phenomenon does not occur, based on the change in the relationship between the speed of the ultrasonic transducer and the drive frequency accompanying the change in duty ratio. The drive signal output circuit 136 outputs a drive signal according to the set drive frequency to the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b. According to the above configuration, since the drive control method can be determined so that the difference in drive frequency does not approach the natural frequency of the friction member 102, it is possible to reduce the decrease in drive efficiency due to the beat phenomenon.

FIG. 4 is a flowchart illustrating control processing of the ultrasonic motor.
In FIG. 4, only the process when simultaneously driving a plurality of ultrasonic transducers is illustrated, the process of confirming whether or not the plurality of ultrasonic transducers are simultaneously driven, and only one ultrasonic transducer is driven. The process in the case of performing is omitted.

  First, a command value output circuit (not shown) generates a command value as a target point (step S1). Subsequently, the first position encoder 131a and the second position encoder 131b output the position information of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b to the position deviation calculation circuit 132, respectively (Step S2).

  Next, the position deviation calculation circuit 132 compares the command value with the position information to calculate the position deviation (step S3). Subsequently, the drive frequency setting circuit 133 sets the drive frequency to be output to the first ultrasonic transducer 115a and the second ultrasonic transducer 115b based on the calculated positional deviation (step S4). .

  Next, the frequency calculation circuit 134 calculates the difference between the drive frequency of the first ultrasonic transducer 115a and the drive frequency of the second ultrasonic transducer 115b (step S5). Then, the drive control method determination circuit 135 compares the calculation result with a predetermined threshold value to determine the drive control method of each of the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b (Step S6).

  The drive signal output circuit 136 inputs drive signals to the first and second ultrasonic transducers in accordance with the drive control method determined by the drive control method determination circuit 135 (step S7). Thereby, each ultrasonic transducer is driven (step S8).

  Next, the first position encoder 131a and the second position encoder 131b respectively capture position information of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b (step S9). Subsequently, the positional deviation calculation circuit 132 determines whether all the ultrasonic transducers have reached the target point based on the acquired positional information (step S10). If all the ultrasonic transducers have reached the target point, the drive control ends (step S10). If there is an ultrasonic transducer that has not reached the target point, the process returns to step S4. According to the present flowchart, it is possible to reduce the decrease in drive efficiency due to the beat phenomenon by repeating the above flow until the simultaneous drive is finished. When (n-1) ultrasonic transducers reach the target point among n ultrasonic transducers, the beat phenomenon stops, so the target of (n-1) ultrasonic transducers The drive control may be ended on the condition that the point is reached.

FIG. 5 is a diagram showing the relationship between the drive frequency and the velocity of the ultrasonic transducer.
In FIG. 5, the relationship between the driving frequency and the velocity of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b will be described as an example. In this embodiment, the first ultrasonic motor 101a and the second ultrasonic motor 101b have the same configuration, and the first ultrasonic motor 101a will be representatively described in order to simplify the description.

  The ultrasonic motor 101a excites ultrasonic vibration by applying a drive voltage to the piezoelectric element 105a, whereby the ultrasonic transducer 115a resonates. As a result, an elliptical motion occurs in the ultrasonic transducer 115 a to obtain a driving force. That is, since the ultrasonic motor 101a uses the resonance of the ultrasonic transducer 115a, the speed changes according to the relationship between the drive frequency input to the piezoelectric element 105a and the resonant frequency of the ultrasonic transducer 115a. Therefore, the desired velocity v can be obtained by changing the drive frequency f input to the piezoelectric element 105a.

  5A and 5B respectively show the relationship between the driving frequency and the velocity of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b. The first ultrasonic transducer 115a has a drive frequency f1 set to obtain a velocity v1 from the result of position deviation calculation. The second ultrasonic transducer 115b has a drive frequency f2 set to obtain the velocity v2 from the result of position deviation calculation. The frequency calculation circuit 134 calculates the difference between the drive frequency f1 and the drive frequency f2. Based on the calculation result of this difference, the drive control method determination circuit 135 changes the duty ratio of the drive voltage applied to the second ultrasonic transducer 115 b. Specifically, the duty ratio of the drive voltage of the vibrator is changed according to the value of the difference of the drive frequency, and the drive frequency of the vibrator is changed.

  In FIG. 5B, the solid line 151a shows the relationship between the drive frequency and the speed before the duty ratio of the drive voltage applied to the second ultrasonic transducer 115b is changed. Further, a broken line 151b indicates the relationship between the drive frequency and the speed after the duty ratio of the drive voltage is changed.

  Although FIG. 5B shows, as an example, the relationship between the drive frequency and the speed when the duty ratio of the drive voltage is reduced, if the duty ratio of the drive voltage is changed, FIG. It is not limited to the example shown to).

  When the duty ratio of the drive voltage is reduced, the drive voltage is reduced. As a result, the relationship between the drive frequency and the speed changes from the solid line 151a to the broken line 151b, and the frequency for outputting the desired speed v2 changes from f2a to f2b. As a result, the difference in drive frequency between the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b can be changed from dfa to dfb. Further, in order to avoid a rapid decrease in speed, a predetermined drive frequency may be shifted in consideration of the difference in frequency calculated by the frequency calculation circuit 134 in advance.

Although FIG. 5 shows the result of changing the duty ratio of the drive voltage applied to the second ultrasonic transducer 115b, the duty of the drive voltage applied to the first ultrasonic transducer 115a is shown. You may change the ratio. Furthermore, the respective duty ratios of the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b may be changed.
As described above, according to the present invention, it is possible to provide an ultrasonic motor capable of independently driving at an arbitrary speed while reducing the beating phenomenon due to the difference in the driving frequency of the plurality of ultrasonic transducers.

(Example 2)
Example 2 will be described below. In the ultrasonic motor of the second embodiment, the same reference numerals are given to the portions having the same configuration as the ultrasonic motor 101a and the ultrasonic motor 101b of the first embodiment, and the description will be omitted.

FIG. 6 is a view showing a piezoelectric element applied in the second embodiment.
The piezoelectric element 201 has an adjacent first electrode 202a and a second electrode 202b. The piezoelectric element 201 and the vibrating plate 104b are bonded to each other to constitute a second ultrasonic transducer 115b. Then, the ultrasonic transducer 115 b is brought into pressure contact with the friction member 102. At this time, two vibration modes can be generated by inputting a drive signal having a predetermined phase difference between the first electrode 202a and the second electrode 202b. The combination of the two vibration modes causes the above-mentioned approximately elliptic motion. In this state, by changing the phase difference between the drive signals input to the first electrode 202a and the second electrode 202b, the ellipticity ratio of the substantially elliptic motion generated in the contact portion 116b of the diaphragm 104b is changed. This makes it possible to change the speed.

  In the present embodiment, in the case where the first ultrasonic transducer 115b of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b is constituted by the piezoelectric element 201 and the above-mentioned diaphragm 104b. However, the present invention is not limited to this configuration. Both the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b may be configured by the piezoelectric element 201. Moreover, in the present embodiment, although the piezoelectric element 201 having the first electrode 202a and the second electrode 202b adjacent to each other is used, an ultrasonic wave that generates a substantially elliptical motion by using a combination of two vibration modes It may be a vibrator.

FIG. 7 is a diagram showing a drive signal input to the electrode of the piezoelectric element constituting the ultrasonic transducer in the second embodiment.
In FIG. 7, a drive signal input to the first electrode 202a and the second electrode 202b of the piezoelectric element 201 constituting the second ultrasonic transducer 115b will be described as an example. The electrode 1 and the electrode 2 described in FIG. 7 are synonymous with the first electrode 202a and the second electrode 202b, respectively.

  In the example shown in FIG. 7A, a drive signal is input with a phase difference φa to the first electrode 202a and the second electrode 202b. When two vibration modes are used, the phase difference φa may be about 90 degrees as an example of a suitable phase difference, but it is not limited thereto.

  In the example illustrated in FIG. 7B, a drive signal is input with a phase difference φb to the first electrode 202a and the second electrode 202b. In the present embodiment, the phase difference is determined by the drive control method determination circuit 135, and the phase difference changes from φa to φb. At this time, in the substantially elliptic motion formed by the two vibration modes, the ellipticity ratio is changed so that the velocity becomes faster or slower. Thus, by changing the phase difference, it is possible to change the elliptic ratio of the substantially elliptic motion and to change the speed.

FIG. 8 is a diagram showing the relationship between the driving frequency f of the ultrasonic transducer and the velocity v in the second embodiment.
FIG. 8A shows the relationship between the driving frequency of the first ultrasonic transducer 115a and the velocity. FIG. 8B shows the relationship between the drive frequency of the second ultrasonic transducer 115 b and the velocity.

  The first ultrasonic transducer 115a and the second ultrasonic transducer 115b set the drive frequency f1 and the drive frequency f2 to obtain the velocity v1 and the velocity v2, respectively, from the results of position deviation calculation. Then, the frequency calculation circuit 134 calculates the difference between the drive frequency f1 and the drive frequency f2. The drive control method determination circuit 135 changes the phase difference between the two drive signals applied to the second ultrasonic transducer 115b based on the difference between the drive frequency f1 and the drive frequency f2.

  In FIG. 8B, the solid line 221 shows the relationship between the drive frequency and the speed when two drive signals are applied to the second ultrasonic transducer 115 b with the phase difference φa. The broken line 222 shows the relationship between the drive frequency and the speed when two drive signals are applied to the second ultrasonic transducer 115 b with a phase difference φb.

  In the present embodiment, when the phase difference is increased, as described above, the ellipticity ratio of the substantially elliptic motion changes. As a result, the relationship between the drive frequency and the speed changes from the solid line 221 to the broken line 222, and the frequency for outputting the desired speed v2 changes from fφa to fφb. As a result, the difference in drive frequency between the first ultrasonic transducer 115 a and the second ultrasonic transducer 115 b can be changed from dfa to dfb. Further, in order to avoid a rapid decrease in speed, a predetermined drive frequency may be shifted in consideration of the difference in frequency calculated by the frequency calculation circuit 134 in advance. In addition, although the case where a phase difference becomes large is demonstrated as an example in this description, it does not restrict to this.

  According to the present invention, it is possible to provide an ultrasonic motor capable of independently driving at an arbitrary speed while reducing the beating phenomenon due to the difference in driving frequency of a plurality of ultrasonic transducers. As mentioned above, although the preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  101a Ultrasonic motor

Claims (12)

A first oscillator,
A second oscillator,
A friction member in common contact with the first vibrator and the second vibrator;
Drive control means for performing drive control of the first vibrator and the second vibrator;
A vibration-type actuator in which the first vibrator, the second vibrator, and the friction member move relative to each other by vibrating the first vibrator and the second vibrator.
The drive control means is configured to set the first vibrator and the second vibrator so that the difference between the drive frequency of the first vibrator and the drive frequency of the second vibrator does not match the natural frequency of the friction member. A vibration-type actuator that performs drive control of the vibrator of 2. The drive control means is configured to calculate the first vibrator and the second vibrator based on the difference between the drive frequency of the first vibrator and the drive frequency of the second vibrator obtained by calculation. The vibration-type actuator according to claim 1, wherein drive control is performed. The vibration type actuator according to claim 1 or 2, wherein the first vibrator and the second vibrator, and the friction member move relative to each other in a straight direction. The relative movement direction of the said 1st vibrator | oscillator with respect to the said friction member is as substantially equal as the relative movement direction of the said 2nd vibrator | oscillator with respect to the said friction member. Vibration type actuator. The first vibrator and the second vibrator are arranged in series with respect to the relative movement direction of the first vibrator or the relative movement direction of the second vibrator. The vibration type actuator according to claim 3 or 4. The first vibrator and the second vibrator are arranged in parallel with respect to the relative movement direction of the first vibrator or the relative movement direction of the second vibrator. The vibration type actuator according to claim 3 or 4. Each of the first vibrator and the second vibrator includes a diaphragm and a piezoelectric element fixed to the diaphragm.
The vibration type actuator according to any one of claims 1 to 6, wherein the piezoelectric element excites ultrasonic vibration to generate an elliptical motion at a contact portion of the diaphragm with the friction member. . The elliptical motion generated at the contact portion of the diaphragm is formed by combining two vibration modes generated by applying at least two drive signals to the piezoelectric element,
The drive control unit changes the phase difference between the two drive signals with respect to each of the first vibrator and the second vibrator, thereby the first vibrator and the second vibrator. The vibration type actuator according to claim 7, wherein the drive frequency of is changed. The vibration type according to claim 8, wherein each of the piezoelectric elements included in the first vibrator and the second vibrator has first and second electrodes to which the drive signal is given. Actuator. A lens barrel using the vibration-type actuator according to any one of claims 1 to 9 as a drive source. A camera using the vibration-type actuator according to any one of claims 1 to 9 as a drive source. A first vibrator and a second vibrator, and a friction member with which the first vibrator and the second vibrator are in common contact, and the first vibrator and the second vibrator A control method of a vibration-type actuator in which the first and second vibrators and the friction member move relative to each other by vibrating the vibrator.
Driving of the first vibrator and the second vibrator such that the difference between the driving frequency of the first vibrator and the driving frequency of the second vibrator does not match the natural frequency of the friction member A control method comprising a drive control step of performing control.

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