JP6971816B2 - Drive device, its control method, vibration wave motor device, and image pickup device - Google Patents

Description

The present invention relates to a drive device, a control method thereof, a vibration wave motor device, and an image pickup device, and more particularly to a drive device for driving a pan head device on which a surveillance camera, a network camera, or the like is mounted.

In general, a vibration wave motor (also referred to as an ultrasonic motor) has a low speed and a high torque, and is therefore often used in electronic devices that directly drive without using a speed reducer. In recent years, it has been proposed to use a vibration wave motor as a drive source of a pan head device that freely controls the direction of the optical axis in an image pickup device, which is one of electronic devices. In other words, the aim is to enhance the rotational operation of the pan head device by direct drive by taking advantage of the characteristics of the vibration wave motor, which is low speed and high torque. Further, since the vibration wave motor has a friction holding force when it is not energized, it is not necessary to separately provide a holding force generating mechanism such as a brake, and a compact configuration can be realized.

It is also proposed to mount the vibration wave motor on other rotating equipment by taking advantage of the above-mentioned characteristics of the vibration wave motor. For example, there is one that uses a vibration wave motor to open and close the door mirror (see Patent Document 1). Patent Document 1 describes a detection unit that detects that a disturbance is applied from the output side of the vibration wave motor when the vibration wave motor is held by the holding force when the vibration wave motor is not energized.

Specifically, when the frictional contact surface of the vibration wave motor slips due to disturbance, a detection unit for detecting the self-excited vibration of the vibrating body excited by the slip is provided. Then, the detection result by the detection unit is sent to the control unit, and the control unit requests the drive device to output a drive signal, and quickly drives the vibration wave motor so as not to cause wear of the friction surface and unpleasant noise.

In Patent Document 1, the direction in which the vibration wave motor operates is predetermined as the recovery operation after the occurrence of slippage.

Japanese Unexamined Patent Publication No. 4-779775

By the way, in a camera such as a surveillance camera or a network camera whose usage environment and usage method are different for each user, it is unknown in which axis and in what rotation direction the disturbance acts. Therefore, it is difficult to avoid damage to the frictional contact surface by the operation of the predetermined vibration wave motor. On the other hand, a mechanism is known that vibrates a standing wave to reduce the frictional force on the frictional contact surface only to avoid damage.

However, when the mechanism for reducing the frictional force is used, when the friction holding state is released, the device group attached to the driven body side of the pan head device suddenly changes its attitude under the influence of gravity. It ends up.

Therefore, an object of the present invention is a drive device capable of avoiding damage to the frictional contact surface when using a vibration wave motor and preventing a posture change when the friction holding state is released, and a control method thereof. , A vibration wave motor device, and an image pickup device.

In order to achieve the above object, the drive device according to the present invention has a vibrating body having an electric-mechanical energy conversion element, and is a drive device that drives and controls a vibration wave motor that relatively moves the vibrating body and the driven body. The electric-mechanical energy conversion element has a sensor electrode that outputs a detection signal corresponding to the vibration of the vibrating body, and the driving device has the vibrating body and the driven device based on the detection signal. have a determining means for determining a direction for relatively moving the body, the sensor electrodes, characterized in that it is also used as a driving electrode the drive signal is input.

According to the present invention, when the vibration wave motor is used, it is possible to avoid damage to the friction contact surface and prevent the posture change when the friction holding state is released.

It is a figure which shows the vibrating body used in the drive device by 1st Embodiment of this invention, and the vibration wave motor using the vibrating body. It is a figure for demonstrating the electrode pattern and the polarization direction of the piezoelectric element shown in FIG. It is a figure for demonstrating an example of the drive device by 1st Embodiment of this invention. It is a figure for demonstrating an example of the output signal of the sensor phase at the time of slip occurrence by forcibly rotating the output shaft of a vibration wave motor in the CW direction. It is a figure for demonstrating the output signal immediately after the slip occurrence of the sensor A phase and the sensor B phase when the output shaft of a vibration wave motor is forcibly rotated. It is a figure for demonstrating the mechanism which the phase difference occurs in the output signal of the sensor A phase and the sensor B phase according to the rotation direction of a driven body. It is a figure for demonstrating an example of the drive device by 2nd Embodiment of this invention. It is a figure for demonstrating an example of the drive device by the 3rd Embodiment of this invention. It is a figure which shows schematic the whole structure of the image pickup apparatus according to 4th Embodiment of this invention. It is a figure which shows schematic the internal structure of the image pickup apparatus of FIG.

Hereinafter, an example of the drive device according to the embodiment of the present invention will be described with reference to the drawings. In the following description, a drive device for driving a pan head device equipped with a surveillance camera, a network camera, or the like will be described.

[First Embodiment]
FIG. 1A is a perspective view showing a vibrating body of a vibration wave motor used in a driving device according to the first embodiment of the present invention.

The vibrator 5 shown, a metal elastic body 1 and the electric formed annular shape - and a pressure conductive element 2 Ru 1 Tsudea of mechanical energy conversion element. A radial groove 4 is formed on one surface side of the elastic body 1 in order to increase the displacement in the circumferential direction due to bending vibration. The piezoelectric element 2 is fixed to the surface opposite to the one surface on which the groove portion 4 is formed by adhesion or the like.

FIG. 1B is a cross-sectional view showing the overall configuration of the vibration wave motor.

The driven body 10 has a cylindrical contact body 11 and a mass portion 12. The driven body 10 is pressed against the elastic body 1 of the vibrating body 5 by the pressure spring 13, and the driven body 10 and the vibrating body 5 come into pressure contact with each other due to the applied pressure. The frictional force generated on the contact surface between the driven body 10 and the vibrating body 5 (hereinafter referred to as “friction contact surface”) becomes the driving force to drive the driven body 10, and the rotational torque of the driven body 10 is pressurized. It is transmitted to the shaft 15 via the spring 13 and the disc 14. The vibrating body 5 is provided with a thin plate supporting portion 16 for supporting the vibrating body 5.

FIG. 2 is a diagram for explaining an electrode pattern and a polarization direction of the piezoelectric element shown in FIG. 2 (a) is a diagram showing a pattern electrode surface, and FIG. 2 (b) is a diagram showing a common electrode surface located on the back surface of the electrode surface.

With reference to FIGS. 1 and 2, the common electrode surface shown in FIG. 2B is fixed to the elastic body 1, and the common electrode 3a is electrically conductive with the elastic body 1. On the other hand, the pattern electrodes 3 are formed radially on the pattern electrode surface shown in FIG. 2 (a). The pattern electrode 3 is composed of 28 electrodes having a width of 1/4 of the length of one wavelength (λ) of the drive vibration. That is, the vibrating body 5 uses the seventh-order bending vibration having seven peaks in one circumference as the drive vibration mode.

In this drive vibration mode, when the piezoelectric element 2 contracts in the thickness direction, it expands in the direction orthogonal to the thickness direction. On the other hand, when the piezoelectric element 2 extends in the thickness direction, shrinkage occurs in the direction orthogonal to the thickness direction. In the length of one wavelength (λ), the piezoelectric element 2 makes a quarter wavelength (λ / 4) extension and a quarter wavelength (λ / 4) contraction in the circumferential direction half a wavelength (λ / 2). ) At the same time to form a standing wave.

In FIG. 2A, the pattern electrodes 3 are formed all around at a pitch of a quarter wavelength (λ / 4), and the polarization direction of each pattern electrode 3 is shown in the + direction in FIG. 2A. All are formed in the same direction. Therefore, by applying an alternating voltage whose phase is inverted to the two electrodes whose positional phases are shifted by half a wavelength (λ / 2), a standing wave having a frequency of the alternating voltage is generated. At this time, if the pattern electrode 3 to which the alternating voltage of the same phase is applied is, for example, an electrode for generating a standing wave A, it is referred to as an A + phase and an A− phase, respectively.

In a general traveling wave type vibration wave motor, two standing waves having peaks at positions shifted by a quarter wavelength (λ / 4) are excited with a phase difference of 90 degrees in time to generate a traveling wave. do. If these two standing waves are called a standing wave A and a standing wave B, a traveling wave is generated in a total of four phases of A + phase, A-phase, B + phase, and B-phase.

FIG. 3 is a diagram for explaining an example of a drive device according to the first embodiment of the present invention.

In the illustrated drive device, when a disturbance acts on the output shaft side of the vibration wave motor, the friction contact surface is instantly detected and the friction contact surface is reduced. Reduces wear.

The drive device includes a controller 31, a drive signal generation unit 32, a slip detection unit 33, and a phase difference determination unit 34. The controller 31 outputs drive conditions such as the drive rotation speed, the drive amount, and the drive direction of the vibration wave motor as a drive command to drive and control the vibrating body 5 (that is, the vibration wave motor). The drive signal generation unit 32 generates a drive signal to be applied to the vibrating body 5 of the vibration wave motor based on the drive command.

The sensor phase converts the mechanical strain generated in the piezoelectric element 2 in response to the vibration generated in the elastic body 1 by the disturbance into an electric signal by the piezoelectric effect and outputs the signal. In the illustrated example, two of the 28 pattern electrodes 3 are the sensor A phase and the sensor B phase, respectively. On the other hand, the remaining 26 pattern electrodes 3 are used to input the drive signal 4 phase via the FPC substrate (not shown) to cause drive vibration.

The slip detection unit 33 receives the output signals of the sensor A phase and the sensor B phase, and sends the output signals to the phase difference determination unit 34 as first and second detection signals, respectively. When the vibration wave motor is stopped, the slip detection unit 33 stands by in a state where the output signals of the sensor A phase and the sensor B phase can be constantly monitored. Then, the occurrence of slip is detected by capturing the output signal having a minute amplitude when the frictional contact surface is slightly slipped due to the action of the disturbance. With the occurrence of slip, the slip detection unit 33 sends the output signals of the sensor A phase and the sensor B phase to the phase difference determination unit 34 as first and second detection signals, respectively.

The phase difference determination unit 34 compares the first and second detection signals and detects the phase relationship (that is, the phase difference) of the first and second detection signals. Then, the phase difference determination unit 34 determines the rotation direction (that is, the slip generation direction) of the vibration wave motor caused by the disturbance based on the detected phase difference. After that, the phase difference determination unit 34 sends an evaluation result (determination result) indicating the slip generation direction to the controller 31. The controller 31 sends a slip drive command for driving the vibration wave motor in the same direction as the slip generation direction based on the slip generation direction to the drive signal generation unit 32 to reduce the slip of the vibration wave motor.

In this way, by reducing the slippage of the vibration wave motor, it is possible to reduce the wear of the frictional contact surface.

Here, a method for determining the slip generation direction performed by the phase difference determination unit 34 shown in FIG. 3 will be described.

FIG. 4 is a diagram for explaining an example of the output signal of the sensor phase when slip occurs by forcibly rotating the output shaft of the vibration wave motor in the CW direction. 4 (a) is a diagram showing the output signal of the sensor A phase, and FIG. 4 (b) is a diagram showing the output signal of the sensor B phase. Here, the output signal was measured with an oscilloscope. Further, the CW direction means a clockwise direction when viewed from the forming surface (groove forming surface) of the groove portion 4 shown in FIG.

In FIG. 4, the horizontal axis represents time and the vertical axis represents voltage value. The output signal changes in both the sensor A phase (SA) and the sensor B phase (SB) from immediately after the occurrence of the slip (0 seconds) to the end of the slip (0.02 seconds). Then, it can be seen that the output signals of the sensor A phase and the sensor B phase have substantially the same waveforms. At the beginning of the slip, the output signal has a relatively small amplitude, the amplitude increases sharply from around 0.008 seconds, and the slip converges after about 0.01 seconds.

FIG. 5 is a diagram for explaining the output signals immediately after the occurrence of slippage of the sensor A phase and the sensor B phase when the output shaft of the vibration wave motor is forcibly rotated. 5 (a) is a diagram showing an output signal when forced rotation in the CW direction is applied, and FIG. 5 (b) is a diagram showing an output signal when forced rotation in the CCW direction is applied. The CCW direction is a counterclockwise direction when viewed from the groove forming surface shown in FIG.

In the forced rotation in the CW direction, the phase of the output signal in the sensor A phase (SA) lags behind the output signal in the sensor B phase (SB). On the other hand, in the forced rotation in the CCW direction, the phase of the output signal in the sensor A phase (SA) is ahead of the output signal in the sensor B phase (SB). That is, if the phase difference between the output signals of the sensor A phase and the sensor B phase is detected at the beginning of slipping, the slipping occurrence direction (rotational direction) can be determined immediately after slipping occurs.

Here, a mechanism in which a phase difference occurs in the output signals of the sensor A phase and the sensor B phase according to the rotation direction (that is, the relative movement direction) of the driven body 10 will be described.

Now, when a force for forcibly rotating the shaft 15 which is the output shaft of the vibration wave motor acts from the outside and slip occurs on the frictional contact surface between the driven body 10 and the vibrating body 5, the driven body is to relax the frictional force. A traveling wave is generated in the circumferential direction of the vibrating body 5 in the direction opposite to the forced rotation direction of 10. At this time, since the piezoelectric element is distorted by the peaks and valleys of the traveling wave, a sinusoidal output signal is output from the sensor A phase and the sensor B phase according to the piezoelectric effect.

As described above, since the traveling wave propagates in the circumferential direction of the vibrating body 5, the mountain of the traveling wave passes on the sensor electrode arranged at a position having a spatial distance in the propagating direction with a time lag. As a result, a phase difference is generated in the output signals of the sensor A phase and the sensor B phase according to the rotation direction of the driven body 10.

FIG. 6 is a diagram for specifically explaining a mechanism in which a phase difference occurs in the output signals of the sensor A phase and the sensor B phase according to the rotation direction of the driven body.

Now, when the driven body 10 is forcibly rotated in the CW direction indicated by the broken line arrow, a traveling wave in the CCW direction indicated by the solid line arrow is generated in the vibrating body 5. Since the traveling wave identical to the piezoelectric element 2 constituting the vibrator 5 has occurred, the mountain of the traveling wave passes with a time difference Oite sensor A-phase and sensor B phase pattern electrode surface.

As a result, as described with reference to FIG. 5A, the phase of the output signal in the sensor A phase lags behind the output signal in the sensor B phase. Similarly, in the forced rotation in the CCW direction, the traveling wave propagates in the opposite direction. Therefore, as described in FIG. 5B, the phase of the output signal in the sensor A phase is larger than that in the output signal in the sensor B phase. move on. Therefore, if the sensor electrodes are arranged at positions where the timing at which the mountain of the traveling wave passes is shifted in time to form a plurality of sensor phases, the phase difference can be detected.

As described above, it is desirable that the two pattern electrodes 3 close to the rotation direction (relative movement direction) of the driven body 10 are used as the sensor electrodes, but the sensor electrodes do not necessarily have to be adjacent to each other. Further, it is desirable that the plurality of sensor electrodes have the same shape. That is, if the mechanical distortions caused by the traveling waves are the same, the amplitude levels of the two output signals generated from the sensor phases are the same, so it is desirable that the plurality of sensor electrodes have the same shape. If the amplitude level of one of the two output signals to be compared is small, the determination accuracy at the time of phase difference determination may be lowered, and the timing of detecting the start of slip may be delayed.

Furthermore, it is desirable that the areas and arrangements of the plurality of sensor electrodes be designed so that the amplitude levels are the same, taking into consideration the vibration mode of the traveling wave generated by the occurrence of slippage. Further, even if one sensor phase is composed of a plurality of electrode groups, the phase difference can be detected in the same manner. In this case, it is difficult to predict the phase of the output signal of the electrode group. Therefore, the phase relationship of the output signal of the sensor phase due to the difference in the rotation direction is experimentally grasped in advance to configure the drive device. There is a need.

When the vibrating body 5 is driven by the driving device, the rotation direction of the vibrating body 5 (that is, the vibration wave motor) can be determined in the same manner.

Further, the illustrated drive device can be used as an electric assist during manual drive. For example, when a force for sliding the frictional contact surface is applied from the shaft 15 side of the vibration wave motor, the slip detection unit 33 detects a minute slip. Then, the direction in which the vibration wave motor is manually determined is manually determined by the phase difference determination unit 34, and the controller 31 sends a drive command to the drive signal generation unit 32 in order to assist the manual drive.

As described above, in the first embodiment of the present invention, when the friction contact surface of the vibration wave motor slips due to disturbance or the like, the rotation direction of the slip is detected and the vibration wave is in the same direction as the slip direction. Drive the motor. This makes it possible to reduce damage to the vibration wave motor due to disturbance or the like.

[Second Embodiment]
Subsequently, an example of the drive device according to the second embodiment of the present invention will be described.

FIG. 7 is a diagram for explaining an example of a drive device according to a second embodiment of the present invention. In FIG. 7, the same reference numbers are assigned to the same components as those shown in FIG.

Similarly to the drive device shown in FIG. 3, the drive device shown in FIG. 7 also prevents the frictional contact surface from being worn when a disturbance or the like acts on it. In the illustrated drive device, the electrodes used as the sensor phase are also used as the drive phase, as will be described later.

As shown in the figure, a switch 71 is arranged between the sensor A phase / drive phase and the sensor B phase / drive phase and the slip detection unit 33. The switch 71 includes a changeover switch, and switches the sensor phase to the drive phase as described later.

The switch 71 is connected to the controller 31 and the drive signal generation unit 32. When the switch 71 connects the changeover switch to the input side based on the switch command sent from the controller 31, the drive signal generation unit 32 is connected to the sensor A phase and the sensor B phase. As a result, the drive signal is input from the drive signal generation unit 32 to the sensor A phase and the sensor B phase, and the sensor A phase and the sensor B phase become the drive phase.

On the other hand, when the changer 71 connects the changeover switch to the output side based on the switch command, the slip detection unit 33 is connected to the sensor A phase and the sensor B phase, and the state is the same as that of the drive device described with reference to FIG. Will be.

As described above, in the second embodiment of the present invention, the sensor phase (sensor electrode) that does not contribute to the generation of vibration can be selectively used as an electrode for driving, and as a result, the performance of the vibration wave motor is improved. be able to.

When the vibration wave motor is driven, the sensor phase not used for driving causes unevenness in the traveling wave in the driving vibration, which contributes to the wear of the friction contact surface. Therefore, as described above, when driving the vibration wave motor, if the entire surface of the piezoelectric element 2 is used as the drive phase by the switch 71, the unevenness of the traveling wave can be reduced and the life of the vibration wave motor can be extended. Can be done.

When evaluating the output signal of the sensor phase by the current value, if the area of the sensor phase is widened, the mechanical strain can be efficiently converted into the amount of electric charge. Therefore, if the drive device shown in FIG. 7 is used, the sensitivity of disturbance detection can be increased by using all of the pattern electrodes 3 of the piezoelectric element 2 as the sensor phase when detecting disturbance or the like.

[Third Embodiment]
Next, an example of the drive device according to the third embodiment of the present invention will be described.

FIG. 8 is a diagram for explaining an example of a drive device according to a third embodiment of the present invention. In FIG. 8, the same reference numbers are assigned to the same components as those shown in FIG. Further, also in the drive device shown in FIG. 8, the frictional contact surface is prevented from being worn when a disturbance or the like acts, as in the drive device shown in FIG.

The illustrated drive device includes an encoder 81 and a movement amount detection unit 82, and the encoder 81 is a displacement sensor that outputs a mechanical displacement amount due to rotation of a driven body 10 driven by a vibration wave motor as a displacement signal. Is. When the slip detection unit 33 detects slip due to disturbance, the slip detection unit 33 sends an operation command to the encoder 81. Upon receiving the operation command, the encoder 81 outputs a displacement signal. The movement amount detection unit 82 acquires the rotation amount (that is, the drive amount) of the driven body 10 based on the displacement signal, and sends it to the controller 31 as a measurement result.

In the standby state in which the vibration wave motor is stopped, the encoder 81 is not energized, and when an operation command is received from the slip detection unit 33, the encoder 81 operates. The encoder 81 may be operated even in the standby state.

The controller 31 is based on the rotation direction (evaluation result) received from the phase difference determination unit 34 and the rotation amount (measurement result: detection result) received from the movement amount detection unit 82, and the initial position of the vibration wave motor before the disturbance action. Is calculated. Then, the controller 31 sends a drive command for returning the vibration wave motor to the initial position to the drive signal generation unit 32. The drive signal generation unit 32 sends a drive signal corresponding to the drive command to the vibrating body 5 (vibration wave motor), and returns the rotation position of the vibration wave motor to the initial position.

By the way, if the absolute encoder is used to constantly perform sensing to detect the rotational position of the vibration wave motor, the vibration wave motor can be returned to the initial position in the same manner. On the other hand, in the illustrated drive device, the cost can be reduced as a result of being able to use the incremental encoder. In addition, since the encoder does not always perform sensing, the standby power when the vibration wave motor is stopped can be reduced.

As described above, in the third embodiment of the present invention, in addition to the effect of the first embodiment described above, the rotational position of the vibration wave motor can be returned to the initial position with a simple configuration. In the third embodiment of the present invention, since the driven body 10 is moving, the encoder 81 detects the displacement of the driven body 10, but the vibrating body 5 is moving instead of the driven body 10. In this case, the encoder 81 may detect the displacement of the driven body 10 and execute the same drive control as described above.

[Fourth Embodiment]
Next, an example of the image pickup apparatus according to the fourth embodiment of the present invention will be described. In the present embodiment, the vibration wave motor device having the drive device and the vibration wave motor according to any one of the above-described first to third embodiments is used as a motor device for pan drive and tilt drive in the image pickup device. .. This image pickup device can be used for a surveillance camera, a network camera, and the like.

FIG. 9 is a diagram schematically showing the configuration of the entire image pickup apparatus 100 according to the present embodiment. The dome component 101 is integrally attached to the cover 102, and the integrated dome component 101 and the cover 102 constitute the dome cover. The cover 102 is attached to the case 103 and covers the image pickup apparatus 100. Further, an inner case 104 is attached inside the case 103.

FIG. 10 is a diagram schematically showing the internal configuration of the image pickup apparatus 100. The image pickup apparatus 100 is roughly divided into a camera unit 200 and a rotary table unit 300.

The camera unit 200 has the following configuration. The lens unit 201 having an optical system such as a lens and an image pickup element such as a CCD or CMOS is supported by a lens frame unit 202 having a tilt rotation axis. A camera cover 203 for covering the lens unit 201 is attached to the lens frame unit 202. Further, a vibration wave motor device 302, which will be described later, for rotationally driving the camera unit 200 in the tilt direction is fixed to the lens frame unit 202.

The rotary table unit 300 has the following configuration. The rotary table 301 supports the camera unit 200 so as to be rotatable in the tilt direction. The vibration wave motor device 302 can directly drive the camera unit 200 to rotate in the tilt direction. The vibration wave motor device 302 has a drive device and a vibration wave motor according to any one of the above-mentioned first to third embodiments. The control board (not shown) is fixed to the rotary table 301.

Further, a vibration wave motor device 303 for rotationally driving in the pan direction is attached to the rotary table 301. The vibration wave motor device 303 can directly drive the rotary table 301 to rotate in the pan direction. As the vibration wave motor device 303, a vibration wave motor device having the drive device and the vibration wave motor according to any one of the above-mentioned first to third embodiments can be used. The vibration wave motor device 303 is fixed to a fixed sheet metal (not shown) provided with a pan bearing unit. The fixed sheet metal is installed in the inner case 104 of FIG.

Although the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments, and various embodiments within the range not deviating from the gist of the present invention are also included in the present invention. ..

For example, the function of the above embodiment may be used as a control method, and the drive device may be made to execute this control method. Further, a program having the functions of the above-described embodiment may be used as a control program, and the control program may be executed by a computer included in the drive device. The control program is recorded on, for example, a computer-readable recording medium.

[Other embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1 Elastic body 2 Piezoelectric element 3 Pattern electrode 4 Groove 5 Vibrating body (vibration wave motor)
31 Controller 32 Drive signal generator 33 Slip detection unit 34 Phase difference determination unit 71 Switcher

Claims (11)

A drive device having a vibrating body having an electric-mechanical energy conversion element and driving and controlling a vibrating wave motor that relatively moves the vibrating body and the driven body.
The electric-mechanical energy conversion element has a sensor electrode that outputs a detection signal corresponding to the vibration of the vibrating body.
The drive device may have a determining means for determining a direction for relatively moving the said driven member and said vibrating member on the basis of the detection signal,
The sensor electrode is a drive device that is also used as a drive electrode into which a drive signal is input . The electric-mechanical energy conversion element has a drive electrode into which a drive signal is input.
The drive device according to claim 1, wherein the drive device includes a control means for controlling the vibration wave motor based on the drive signal according to the determination result by the determination means. The sensor electrode has a first sensor electrode and a second sensor electrode.
The determination means 1 or 2 is characterized in that the determination means determines the direction based on the phase difference between the detection signal output by the first sensor electrode and the detection signal output by the second sensor electrode. The drive device described in. Claims 1 to 3 are characterized in that the determination means determines the direction when a slip occurs between the vibrating body and the driven body when the vibration wave motor is stopped. The drive device according to any one of the above items. The drive device according to any one of claims 1 to 4, wherein the sensor electrode is used as the sensor electrode when the vibration wave motor is stopped. The drive device according to any one of claims 1 to 5, further comprising a switching means for switching the sensor electrode to the drive electrode. It has a moving amount detecting means for detecting the moving amount of the vibrating body or the driven body.
The drive device according to claim 2, wherein the control means controls the vibration wave motor based on the drive signal according to the determination result by the determination means and the detection result of the movement amount detecting means. .. A displacement sensor that detects the displacement of the vibrating body or the driven body, and
1. To claim 1, wherein the slip detecting unit operates the displacement sensor when a slip occurs between the vibrating body and the driven body when the vibration wave motor is stopped. 7. The drive device according to any one of 7. It is a control method of a drive device having a vibrating body having an electric-mechanical energy conversion element and driving and controlling a vibrating wave motor that relatively moves the vibrating body and the driven body.
A step of detecting a detection signal corresponding to the vibration of the vibrating body , which is output from a sensor electrode included in the electric-mechanical energy conversion element.
And Luz step to determine the direction of relative movement between the driven body and the vibrating body on the basis of the detection signal,
The step of switching the sensor electrode to the drive electrode to which the drive signal is input, and
A control method comprising: a step of using the sensor electrode as a drive electrode of the vibrating body. A vibration wave motor device comprising the vibration wave motor and the drive device according to any one of claims 1 to 8. An imaging device comprising a lens and the vibration wave motor device according to claim 10 , wherein the lens is moved.

Images