JP6497964B2 - Vibrating actuator, lens barrel, camera, and control method - Google Patents

Description

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

  As a driving source for cameras and lenses, an ultrasonic motor, which is one of vibration actuators, is widely used. The ultrasonic motor has features such as high torque output, high positioning accuracy, and quietness. In recent years, even in a multi-group zoom configuration, a device having a relatively simple structure and a small size 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 a plurality of ultrasonic motors are independently driven at the same time, a beat phenomenon occurs due to a difference in driving frequency, and driving efficiency is reduced. Patent Document 1 discloses a technique for reducing the beat phenomenon by matching the driving frequencies of a plurality of ultrasonic motors.

JP 2008-160913 A

  In the ultrasonic motor disclosed in Patent Document 1, since the drive frequencies input to the plurality of ultrasonic transducers are the same, the plurality of ultrasonic transducers cannot be independently driven at an arbitrary speed.

  The present invention provides a vibration type actuator capable of independently driving a plurality of ultrasonic vibrators and reducing a decrease in driving efficiency due to a beat phenomenon that occurs when driving a plurality of ultrasonic motors simultaneously. For the purpose.

A vibration type actuator according to an embodiment of the present invention includes a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact, and each of the plurality of vibrators is driven independently. It is a vibration type actuator, and the calculation means for calculating the difference between the driving frequencies of the plurality of vibrators and the difference between the driving frequencies of the plurality of vibrators do not approach the natural frequency of the friction member. Drive control means for driving and controlling the vibrator .

  According to the present invention, it is possible to drive a plurality of ultrasonic transducers independently and to reduce a decrease in driving efficiency due to a beat phenomenon that occurs when driving a plurality of ultrasonic motors simultaneously.

It is a figure which shows a vibration type actuator. It is a disassembled perspective view of an ultrasonic motor. It is a figure which shows the main components of an ultrasonic motor. It is a flowchart explaining the control processing of an ultrasonic motor. It is a figure which shows the relationship between the drive frequency and speed of an ultrasonic transducer | vibrator. 6 is a diagram illustrating a piezoelectric element applied in Example 2. FIG. 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 and the speed v of an ultrasonic transducer | vibrator.

Example 1
Below, this embodiment is described in detail based on an accompanying drawing. In the following description, an ultrasonic motor unitized as a vibration type actuator for driving a lens barrel of a digital camera will be described as an example. However, the intended use of the present invention is not limited to ultrasonic motors.

FIG. 1 is a diagram illustrating a vibration type actuator according to the 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. 1B is a partially enlarged view of the first ultrasonic motor 101a. FIG. 2 is an exploded perspective view of the ultrasonic motor.

  In this 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. Only the portion 101a is shown. Note that the vibration type actuator may have an ultrasonic motor having a different configuration.

  Also in FIG. 2, only the first ultrasonic motor 101a is shown in a disassembled state, and description of common parts is omitted. However, since it is necessary to distinguish the ultrasonic transducer, the ultrasonic transducer mounted on the first ultrasonic motor 101a is referred to as the first ultrasonic transducer 115a. In addition, an ultrasonic transducer mounted on the second ultrasonic motor 101b is referred to as a second ultrasonic transducer 115b.

  The ultrasonic vibrator 115a includes 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 pressure mechanism holding member 110a includes 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 pressurizing mechanism holding member 110a. Further, the pressure mechanism holding member 110a includes a holding hole for receiving the elastic member 107a. The spring 109a is sandwiched between the pressure mechanism holding member 110a and the spring guide 108a. As a result, the spring 109a applies pressure 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 pressure unit and the piezoelectric element 105a, and prevents damage to the piezoelectric element 105a.

  The diaphragm 104a includes a contact portion 116a. The contact portion 116a is in contact with the friction member 102 while being pressed by the pressure of the spring 109a. In a state where the diaphragm 104a and the piezoelectric element 105a are bonded, the piezoelectric element 105a excites ultrasonic vibration, thereby generating a substantially elliptical motion at the contact portion 116a of the diaphragm 104a. At this time, two vibration modes are generated in the ultrasonic transducer 115a.

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

  The pressure mechanism holding member 110a is provided with two V-groove moving side guides, into which three spherical rolling members 111a, 112a, and 113a are fitted. On the other hand, in the cover plate 112 as a fixed portion, two V-groove fixed-side guide portions having a predetermined length in the X-axis direction are provided. The rolling members 111a, 112a, and 113a are sandwiched between the moving side guide portion of the pressure mechanism holding member 110a and the fixed side guide portion of the cover plate 112. The moving side guide portion and the fixed side guide portion described above are provided with a movable range limiting portion for limiting the movable range of the rolling members 111a, 112a, and 113a. Omitted.

  The ultrasonic motor shown in FIG. The ground plate 103 and the cover plate 112 are fixed with 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. In addition, on the bottom surface side of the base plate 103, the friction member 102 is fixed with 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 applied pressure generated in the pressurizing unit will be described. The pressure applied by the spring 109a is an urging force that pressurizes the ultrasonic vibrator 115a against the friction member 102 via the elastic member 107a. The contact portion 116a of the diaphragm 104a contacts the friction member 102 in a pressurized state. On the other hand, the pressure 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 driving 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 retreat in the X-axis direction.

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

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

  In FIG. 1, the first ultrasonic motor 101 a and the second ultrasonic motor 101 b share the cover plate 112 as a fixing portion and are arranged in series, but the configuration is not limited thereto. For example, the form arrange | positioned in parallel may be sufficient.

  In the configuration shown in FIG. 1, the friction member has a contact surface in which the first ultrasonic transducer 115a and the second ultrasonic transducer 115b are in frictional contact in common. The beat phenomenon occurs due to the difference between the drive frequencies input to the first ultrasonic transducer 115a and the second ultrasonic transducer 115b. When the above difference becomes a value close to the natural frequency of the friction member 102 that is shared, the difference greatly resonates and the driving efficiency of the ultrasonic motor decreases. 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 determined based on the result. decide.

FIG. 3 is a diagram illustrating main components of the ultrasonic motor.
In this embodiment, the ultrasonic motor includes a first position encoder 131a that captures position information of the first ultrasonic transducer 115a and a second position encoder that captures position information of the second ultrasonic transducer 115b. 131b.

  The ultrasonic motor also includes a position deviation calculation circuit 132 that compares the position information output from the first position encoder 131a and the second position encoder 131b with each target position to calculate a position deviation. Yes. Further, the ultrasonic motor includes a drive frequency setting circuit 133 that sets the drive frequencies of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b. 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 has a drive control method determination circuit 135 that determines a drive control method based on the calculation result of the frequency calculation circuit 134, and a drive that outputs a drive signal to the drive method determined by the drive control method determination circuit 135. And a signal output circuit 136.

  The first position encoder 131a outputs the position information of the first ultrasonic transducer 115a to the position deviation calculation circuit 132. In addition, 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 second ultrasonic transducer 115b with the respective target positions, and compares the first ultrasonic transducer 115a and the second ultrasonic transducer 115a with the second ultrasonic transducer 115a. Each positional deviation of the ultrasonic transducer 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 115a and the second ultrasonic transducer 115b from the above positional deviation. For example, the drive frequency setting circuit 133 sets the drive frequency so as to increase the speed when the position deviation is large. The frequency calculation circuit 134 calculates the difference between the drive frequencies of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b set by the drive frequency setting circuit 133, respectively.

Here, when the drive 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 115a and the second ultrasonic transducer 115b are illustrated, the present invention is not limited to this, and when there are a large number of ultrasonic transducers, What is necessary is just to obtain | require the difference of a drive frequency.

  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 value considering the natural frequency of the friction member 102. Based on the comparison result, the drive control method determination circuit 135 determines the drive method of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b. This threshold value is set in advance to a value in the vicinity of the natural frequency of the friction member 102, for example. This is because a beat phenomenon occurs when the difference in drive frequency approaches the natural frequency.

  For example, the drive control method determination circuit 135 changes the duty ratio of the second ultrasonic transducer when the difference in drive frequency is equal to or greater than a threshold value. Then, the drive control method determination circuit 135 sets a drive frequency at which no beat phenomenon occurs based on the change in the relationship between the speed of the ultrasonic transducer and the drive frequency accompanying the change in the duty ratio. The drive signal output circuit 136 outputs a drive signal corresponding to the set drive frequency to the first ultrasonic transducer 115a and the second ultrasonic transducer 115b. According to the above configuration, the drive control method can be determined so that the difference in the drive frequency does not approach the natural frequency of the friction member 102, so that a reduction in drive efficiency due to the beat phenomenon can be reduced.

FIG. 4 is a flowchart for explaining control processing of the ultrasonic motor.
FIG. 4 shows only processing when a plurality of ultrasonic transducers are driven simultaneously, processing for checking whether or not a plurality of ultrasonic transducers are driven simultaneously, and driving only one ultrasonic transducer. The processing when doing so is omitted.

  First, a command value output circuit (not shown) generates a command value serving 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 output to the first ultrasonic transducer 115a and the second ultrasonic transducer 115b based on the calculated position 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, and determines the respective drive control methods for the first ultrasonic transducer 115a and the second ultrasonic transducer 115b (step). S6).

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

  Next, the first position encoder 131a and the second position encoder 131b take in the position information of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b, respectively (step S9). Subsequently, the position deviation calculation circuit 132 determines whether all the ultrasonic transducers have reached the target point based on the acquired position information (step S10). When 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 this flowchart, by repeating the above flow until the simultaneous driving is completed, it is possible to reduce a decrease in driving efficiency due to a beating phenomenon. Note that when (n−1) ultrasonic transducers reach the target point among the n ultrasonic transducers, the beat phenomenon stops, so the target of (n−1) ultrasonic transducers. The drive control may be terminated on condition that the point is reached.

FIG. 5 is a diagram showing the relationship between the driving frequency and the speed of the ultrasonic transducer.
In FIG. 5, the relationship between the driving frequency and the speed 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 described as a representative for the sake of simplicity.

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

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

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

  FIG. 5B shows, as an example, the relationship between the drive frequency and the speed when the duty ratio of the drive voltage is lowered. However, if the duty ratio of the drive voltage is changed, FIG. The example shown in FIG.

  When the duty ratio of the drive voltage is lowered, the drive voltage is lowered. As a result, the relationship between the driving 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. Thereby, the difference of the drive frequency of the 1st ultrasonic transducer | vibrator 115a and the 2nd ultrasonic transducer | vibrator 115b can be changed from dfa to dfb. In order to avoid a rapid decrease in speed, a predetermined drive frequency may be shifted in consideration of the frequency difference calculated in advance by the frequency calculation circuit 134.

FIG. 5 shows the result of changing the duty ratio of the drive voltage applied to the second ultrasonic transducer 115b, but the duty of the drive voltage applied to the first ultrasonic transducer 115a. The ratio may be changed. Further, the duty ratios of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b may be changed.
As described above, according to the present invention, it is possible to provide an ultrasonic motor capable of reducing the beat phenomenon due to the difference between the driving frequencies of a plurality of ultrasonic transducers and independently driving at any speed.

(Example 2)
Example 2 will be described below. In addition, about the ultrasonic motor of Example 2, the same code | symbol is attached | subjected to the location which has the same structure as the ultrasonic motor 101a and ultrasonic motor 101b of Example 1, and description is abbreviate | omitted.

FIG. 6 is a diagram illustrating a piezoelectric element applied in the second embodiment.
The piezoelectric element 201 includes a first electrode 202a and a second electrode 202b that are adjacent to each other. The piezoelectric element 201 and the vibration plate 104b are bonded to form a second ultrasonic vibrator 115b. Then, the ultrasonic transducer 115 b is in pressure contact with the friction member 102. At this time, two vibration modes can be generated by inputting a driving signal having a predetermined phase difference between the first electrode 202a and the second electrode 202b. By synthesizing these two vibration modes, the above-described substantially elliptical motion is generated. 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 of the substantially elliptical motion generated at the contact portion 116b of the diaphragm 104b is changed. This makes it possible to change the speed.

  In the present embodiment, when the first ultrasonic transducer 115b of the first ultrasonic transducer 115a and the second ultrasonic transducer 115b is composed of the piezoelectric element 201 and the diaphragm 104b described above. 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. In the present embodiment, the piezoelectric element 201 having the first electrode 202a and the second electrode 202b adjacent to each other is used. However, an ultrasonic wave that generates a substantially elliptical motion by using a combination of two vibration modes. Any vibrator may be used.

FIG. 7 is a diagram illustrating drive signals input to the electrodes of the piezoelectric elements that constitute the ultrasonic transducer in the second embodiment.
In FIG. 7, a description will be given by taking, as an example, drive signals input to the first electrode 202a and the second electrode 202b of the piezoelectric element 201 constituting the second ultrasonic transducer 115b. The electrode 1 and the electrode 2 shown 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, as an example of a suitable phase difference, the phase difference φa may be about 90 degrees, but is not limited thereto.

  In the example shown in FIG. 7B, a drive signal is input with a phase difference φb to the first electrode 202a and the second electrode 202b. In this 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 elliptical motion formed by the two vibration modes, the ellipticity ratio changes so that the speed becomes faster or slower. Thus, by changing the phase difference, it is possible to change the elliptical ratio of the substantially elliptical motion and change the speed.

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

  The first ultrasonic transducer 115a and the second ultrasonic transducer 115b are set with a driving frequency f1 and a driving frequency f2 in order to obtain a velocity v1 and a velocity v2, respectively, from the position deviation calculation results. 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 115b with the phase difference φa. A broken line 222 indicates the relationship between the drive frequency and the speed when two drive signals are applied to the second ultrasonic transducer 115b with a phase difference φb.

  In this embodiment, when the phase difference is increased, the ellipticity of the substantially elliptical motion changes as described above. 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. Thereby, the difference of the drive frequency of the 1st ultrasonic transducer | vibrator 115a and the 2nd ultrasonic transducer | vibrator 115b can be changed from dfa to dfb. In order to avoid a sudden decrease in speed, a predetermined drive frequency may be shifted in consideration of the frequency difference calculated in advance by the frequency calculation circuit 134. In this description, the case where the phase difference is increased is described as an example, but the present invention is not limited to this.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the beat phenomenon by the difference of the drive frequency of several ultrasonic transducer | vibrators, the ultrasonic motor which can be independently driven at arbitrary speeds can be provided. As mentioned above, although 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 (19)

A vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is driven independently;
A computing means for computing a difference between the driving frequencies of the plurality of vibrators;
A vibration type actuator comprising: drive control means for driving and controlling the vibrator so that a difference in driving frequency between the plurality of vibrators does not approach the natural frequency of the friction member . It said drive control means is adapted to change the duty ratio of the drive voltage of the vibrator according to a difference of a value of the driving frequency, according to claim 1, characterized in that changing the drive frequency of the oscillator Vibration type actuator. The vibrator has a diaphragm and a piezoelectric element fixed to the diaphragm,
Vibrating actuator according to claim 1 or 2 the piezoelectric element is characterized in that the elliptical motion is generated in a contact portion between the friction member of the vibrating plate by exciting the ultrasonic vibrations. 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 vibration type actuator according to claim 3 , wherein the drive control unit changes a drive frequency of the vibrator by changing a phase difference between the two drive signals. 5. The vibration type actuator according to claim 4 , wherein a piezoelectric element included in any one of the plurality of vibrators includes first and second electrodes to which the drive signal is applied. The drive control means drives and controls the vibrator so that a difference value of the drive frequency does not approach the natural frequency value from a threshold value that is separated from the natural frequency value by a preset value. Do
The vibration type actuator according to claim 1, wherein the vibration type actuator is provided. A vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is driven independently;
A computing means for computing a difference between the driving frequencies of the plurality of vibrators;
Drive control means for changing a duty ratio of the drive voltage of the vibrator according to a difference value of the drive frequency and changing the drive frequency of the vibrator.
A vibration type actuator characterized by that. A vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is driven independently;
A computing means for computing a difference between the driving frequencies of the plurality of vibrators;
Drive control means for performing drive control of the vibrator according to the value of the difference,
The vibrator has a diaphragm and a piezoelectric element fixed to the diaphragm,
When the piezoelectric element is excited, an elliptical motion is generated at the 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 means changes the drive frequency of the vibrator by changing a phase difference between the two drive signals.
A vibration type actuator characterized by that. A vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is driven independently;
Drive control means for driving and controlling the vibrator so that the difference between the driving frequencies of the plurality of vibrators does not approach the natural frequency of the friction member.
A vibration type actuator characterized by that. The drive control means drives and controls the vibrator so that a difference value of the drive frequency does not approach the natural frequency value from a threshold value that is separated from the natural frequency value by a preset value. Do
The vibration type actuator according to claim 9. The drive control means drives and controls the vibrator so that a difference value of the drive frequency does not coincide with a value of the natural frequency.
The vibration type actuator according to claim 9. The vibrator has a diaphragm and a piezoelectric element fixed to the diaphragm,
When the piezoelectric element is excited, elliptical motion is generated at the contact portion of the diaphragm with the friction member.
The vibration type actuator according to claim 9, wherein the vibration type actuator is provided. 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 means changes the drive frequency of the vibrator by changing a phase difference between the two drive signals.
The vibration type actuator according to claim 12. The vibration type actuator according to claim 1 is used as a drive source.
A lens barrel characterized by that. The vibration type actuator according to claim 1 is used as a drive source.
A camera characterized by that. A control method of a vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is independently driven,
A calculation step of calculating a difference between the driving frequencies of the plurality of vibrators;
And a drive control step of driving and controlling the vibrator so that a difference in driving frequency between the plurality of vibrators does not approach the natural frequency of the friction member . A control method of a vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is independently driven,
A calculation step of calculating a difference between the driving frequencies of the plurality of vibrators;
And a drive control step of changing a duty ratio of the driving voltage of the vibrator according to a value of the difference of the driving frequency and changing a driving frequency of the vibrator.
A control method characterized by that. A control method of a vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is independently driven,
A calculation step of calculating a difference between the driving frequencies of the plurality of vibrators;
A drive control step of performing drive control of the vibrator according to the value of the difference,
The vibrator has a diaphragm and a piezoelectric element fixed to the diaphragm,
When the piezoelectric element is excited, an elliptical motion is generated at the 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 step changes a drive frequency of the vibrator by changing a phase difference between the two drive signals.
A control method characterized by that. A vibration type actuator having a plurality of vibrators and a friction member in which the plurality of vibrators are in frictional contact in common, and each of the plurality of vibrators is driven independently;
A drive control step of driving and controlling the vibrator so that a difference between the driving frequencies of the plurality of vibrators does not approach the natural frequency of the friction member.
A control method characterized by that.

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