JP2021013219A - Oscillatory driver, lens barrel, and electronic apparatus - Google Patents

Abstract

To achieve a resonance circuit capable of efficiently driving an oscillatory motor.SOLUTION: A resonance circuit has: a step-up transformer; a first inductor connected to one end of a primary winding of the step-up transformer; and a second inductor connected to the other end. The first and second inductors are magnetically coupled, When a current in a reverse phase flows in the first inductor and the second inductor, an in-phase magnetic energy is generated.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vibration type drive device using an electric-mechanical energy conversion element.

The vibration type motor generates high-frequency vibration in an electric-mechanical energy conversion element such as a piezoelectric element coupled to an elastic body by applying an AC voltage to the element, and extracts the vibration energy as continuous mechanical motion. It is a non-electromagnetically driven motor configured as described above.

The circuit that drives the vibration type motor includes a pulse signal generation circuit that generates a pulse signal and a resonance circuit that applies an AC voltage amplified by a coil or a transformer to a piezoelectric element included in the vibrating body. The vibration type motor can control the speed by the frequency, amplitude, and phase difference of the AC voltage applied to the piezoelectric element.

The vibration type motor is used, for example, for driving the autofocus of a camera. High-precision and high-speed positioning control is required for autofocus drive, and for example, position feedback control using a position sensor is performed. The focus lens driven by the vibration type motor is accelerated from the start position to a predetermined speed by the control device, driven at a constant speed, and then controlled to stop while decelerating as it approaches the target position.

Here, in order to drive the focus lens in a short time and at high speed, it is important to design a resonance circuit that maximizes the performance of the vibration type motor. That is, a resonance circuit that efficiently drives the vibration type motor based on the frequency, phase difference, and voltage output by the control calculation is desired. However, when the mechanical arm current flows through the vibrating motor, the impedance on the output side changes, so that the resonance characteristics of the circuit are affected, and waveform distortion occurs in the drive current and drive voltage. In particular, the more a transformer having a high boost rate of 10 to 20 times is used, the more remarkable the tendency becomes, and the performance of the vibration type motor may be impaired.

Patent Document 1 describes a drive circuit for an ultrasonic motor, and specifically discloses a filter circuit for a DC voltage source. That is, by connecting the primary coil of the transformer, the switching element, and the filter element that does not allow high frequency components to pass through in series, the high frequency oscillation generated when the switching element is turned on is suppressed, and the generation of radio noise is generated. It is decreasing.

Further, Patent Document 2 describes a technique for further improving the LC filter circuit, and partially discloses a transducer drive circuit using a coupling inductor. By using a coupled inductor that generates in-phase magnetic energy with respect to in-phase current, it is possible to reduce current ripple and common mode noise due to the switching signal of the class D amplifier.

JP-A-11-1978 Patent No. 5475793

However, the above-mentioned conventional technique is limited to removing noise generated in the circuit, and the effect of improving the performance of the vibration type motor is not sufficient. An object of the present invention is to drive a vibrating motor efficiently.

The means to solve the above problems are
A vibrating body having an electric-mechanical energy conversion element and an elastic body,
With the contact body in contact with the vibrating body,
It comprises a first and second inductors of opposite polarity that are magnetically coupled to each other and are arranged so that the magnetic flux generated by the flowing current strengthens each other.
This is a vibration type drive device in which a resonance circuit is formed by the first inductor, the second inductor, and the electric-mechanical energy conversion element.

According to the present invention, the vibration type motor can be driven efficiently.

It is a figure which shows the drive circuit which concerns on embodiment of this invention. It is a figure explaining the driving principle of the linear drive vibration type motor. It is a figure explaining the drive mechanism part of the lens of a lens barrel. It is a block diagram which shows the schematic structure of the vibration type drive device which concerns on embodiment of this invention. It is a figure which shows the drive circuit which concerns on other embodiment of this invention. It is a figure which shows the drive circuit which concerns on other embodiment of this invention. It is a figure which shows the example of the conventional drive circuit. It is a figure which shows the timing chart of the pulse signal output from the oscillator in the embodiment of this invention. It shows the result of measuring the arrival speed and the average power of a vibrating motor using the phase difference of a two-phase AC signal as an operation parameter, and compares the result with the present invention and a conventional drive circuit. It shows the measurement results of the voltage waveform, the current waveform, and the current differential waveform when the vibration type motor is driven with a phase difference of 90 degrees between the two-phase AC signals, and is compared between the present invention and the conventional drive circuit. .. As another embodiment of the present invention, an example of a drive circuit in which two surface-mounted inductors are magnetically coupled by arranging them facing each other is shown. This is a comparison of the control result for the step signal in the drive circuit of the present invention with the conventional circuit.

As a mode for carrying out the present invention, the vibration type drive device includes a vibrating body having an electric-mechanical energy conversion element and an elastic body, and a contact body in contact with the vibrating body. Further, it includes a first inductor and a second inductor having opposite polarities, which are magnetically coupled to each other and arranged so that the magnetic flux generated by the flowing current strengthens each other. Under such a configuration, a resonance circuit is formed by the first inductor, the second inductor, and the electric-mechanical energy conversion element.

The configuration in which the voltage is applied to the electric-mechanical energy conversion element is not limited, and examples include those using transformer boosting and those using coil boosting.

As a configuration using transformer boosting, a boosting transformer is further provided, and a first inductor is on one end side of the primary winding of the boosting transformer, and a second inductor is on the other end side. It is advisable to take a connected configuration. In that case, the electro-mechanical energy conversion element is connected to one end side and the other end side of the secondary winding of the step-up transformer.

On the other hand, as a configuration using coil boosting, a first inductor is connected to one end of the electro-mechanical energy conversion element, and a second inductor is connected to the other end.

Hereinafter, details will be given with reference to the drawings.

(Overall configuration of vibration type drive device)
FIG. 4 is a block diagram showing a schematic configuration of the vibration type drive device 20 according to the embodiment of the present invention. The vibration type drive device 20 includes a vibration type motor 23, a control device 21, and a position sensor 24. The control device 21 has a control unit 110 and a drive circuit 120. The control unit 110 includes a command unit 111, a control calculation unit 112, and a relative position detection unit 113. The drive circuit 120 has a pulse signal generation circuit 104 and a resonance circuit 105. The vibrating motor 23 has a vibrating body 1 and a contact body 2.

The command unit 111 generates a command value for each time of the relative position. For example, the difference between the relative position of the vibrating body 1 and the contact body 2 detected by the relative position detecting unit 113 composed of an encoder or the like is used as the position deviation. It is calculated by the control calculation unit 112. The control calculation unit 112 that performs feedback control outputs a control signal to the drive circuit 120 as a calculation result based on the position deviation. For the control calculation unit 112, for example, a PID calculation unit or the like is used, but the control calculation unit 112 is not limited to this. Further, a speed control configuration in which the speed deviation is feedback-controlled may be used.

The control signal is obtained by converting the calculation result into the phase difference, frequency, and pulse width, which are the control parameters of the AC voltage. The speed and drive direction of the vibrating motor are controlled based on the control amounts of the phase difference, frequency, and pulse width. In the pulse signal generation circuit 104, two-phase pulse signals having different phases are generated based on the information of the phase difference, the frequency, and the pulse width.

An AC voltage boosted to a desired amplitude by a resonance circuit 105 composed of a coupling inductor and a boosting transformer, which will be described later, is applied to the piezoelectric element of the vibrating body 1 to drive the contact body 2. The position sensor 24 attached to the contact body 2 detects the relative position or relative speed of the vibrating body 1 and the contact body 2. The detected relative position is fed back to the control calculation unit 112, and the vibration type motor is controlled so as to follow the command value for each time. As will be described later, the present invention improves the performance of the vibration type motor by devising the configuration of the resonance circuit 105.

FIG. 2 is a diagram illustrating a driving principle of a linear drive type vibrating motor. The vibrating motor shown in FIG. 2A includes a vibrating body 205 in which a piezoelectric element 204 is adhered to an elastic body 203, and a moving body 201 driven by the vibrating body 205. By applying an AC voltage to the piezoelectric element 204, two vibration modes as shown in FIGS. 2C and 2D are generated, and the moving body 201 in pressure contact with the protrusion 202 is moved in the direction of the arrow. .. FIG. 2B is a diagram showing an electrode pattern of the piezoelectric element 204. For example, the piezoelectric element 204 of the vibrating body 205 is formed with an electrode region divided into two equal parts in the longitudinal direction. Further, the polarization directions in each electrode region are the same direction (+). Of the two electrode regions of the piezoelectric element 204, an AC voltage (VB) is applied to the electrode region located on the right side of FIG. 2 (b), and an AC voltage (VA) is applied to the electrode region located on the left side. .. Assuming that VB and VA have a frequency near the resonance frequency of the first vibration mode and an AC voltage having the same phase, the entire piezoelectric element 204 (two electrode regions) is stretched at one moment and stretched at another moment. It will shrink. As a result, the vibrating body 205 generates vibration in the first vibration mode shown in FIG. 2C. Further, assuming that VB and VA are AC voltages having a frequency near the resonance frequency of the second vibration mode and a phase shift of 180 °, at a certain moment, the electrode region on the right side of the piezoelectric element 204 shrinks and the electrode region on the left side shrinks. The electrode area extends. Also, at another moment, the relationship is reversed. As a result, vibration in the second vibration mode shown in FIG. 2D is generated in the vibrating body 205. By synthesizing the two vibration modes in this way, the moving body 201 is driven in the direction of the arrow in FIG. 2A. Further, the generation ratio of the first vibration mode and the second vibration mode can be changed by changing the phase difference of the AC voltage input to the electrode divided into two equal parts. In this vibration type motor, it is possible to change the speed of the moving body by changing the generation ratio.

In this embodiment, a two-phase drive control device for driving a piezoelectric element, which is an electric-mechanical energy conversion element, by dividing it into two phases will be described as an example, but the present invention is not limited to two-phase drive. It can also be applied to vibration type motors with two or more phases.

FIG. 3 is a diagram illustrating a drive mechanism portion of the lens of the lens barrel. The drive mechanism of the contact body by the vibration type drive device of the present embodiment slidably holds the vibrating body, the contact body, and the contact body, and the "contact body" is in contact with the vibrating body. A member that moves relative to a vibrating body due to vibration generated in the vibrating body. The contact between the contact body and the vibrating body is not limited to the direct contact in which no other member is interposed between the contact body and the vibrating body. The contact between the contact body and the vibrating body is an indirect contact in which another member intervenes between the contact body and the vibrating body if the contact body moves relative to the vibrating body due to the vibration generated in the vibrating body. May be good. The "other member" is not limited to a member independent of the contact body and the vibrating body (for example, a high friction material made of a sintered body). The "other member" may be a surface-treated portion formed on the contact body or the vibrating body by plating, nitriding treatment, or the like.

It has a first guide bar and a second guide bar arranged in parallel. Then, a relative moving force is generated between the vibrating body and the second guide bar by the elliptical motion of the protrusion of the vibrating body generated by applying the driving voltage to the electric-mechanical energy conversion element. As a result, the contact body is configured to be movable along the first and second guide bars. Specifically, the contact body driving mechanism 300 by the vibration type driving device of this embodiment mainly includes a lens holder 302 and a lens 306 which are lens holding members. In addition, it is composed of a vibrating body 301 to which a flexible printed circuit board (not shown) is bonded, a pressurizing magnet 305, two guide bars 304, and a substrate (not shown). Here, the vibrating body 301 will be described as an example.

In the first guide bar 303 and the second guide bar 304 composed of two guide bars, both ends of each of the guide bars are held and fixed by a substrate (not shown) so as to be arranged in parallel with each other. .. The lens holder 302 is formed from a cylindrical holder portion 302a, a holding portion 302b that holds and fixes the vibrating body 301 and the pressurizing magnet 305, and a first guide portion 302c that is fitted with the first guide bar 303 to act as a guide. It is composed. The pressurizing magnet 305 for forming the pressurizing means is a permanent magnet. A magnetic circuit is formed between the pressurizing magnet 305 and the guide bar 304, and an attractive force is generated between these members. The pressurizing magnet 305 is arranged at a distance from the guide bar 304, and the guide bar 304 is arranged so as to be in contact with the vibrating body 301. A pressing force is applied between the guide bar 304 and the vibrating body 301 by the suction force. The two protrusions of the elastic body come into pressure contact with the second guide bar 304 to form the second guide portion. The second guide portion forms a guide mechanism by utilizing the attractive force by magnetism, and the vibrating body 301 and the guide bar 304 may be separated from each other by receiving an external force or the like. Has been dealt with. That is, the fall prevention portion 302d provided on the lens holder 302 hits the guide bar, so that the lens holder 302 returns to a desired position. By giving a desired AC voltage signal to the vibrating body 301, a driving force is generated between the vibrating body 301 and the guide bar 304, and the lens holder is driven by this driving force.

(Configuration of drive circuit)
FIG. 1 is a diagram showing a drive circuit 120 according to an embodiment of the present invention.

The drive circuit 120 includes a pulse signal generation circuit 104 that generates a pulse signal, and a resonance circuit 105 that applies an amplified two-phase AC voltage to a piezoelectric element included in the vibrating body. For convenience of explanation, a drive unit that outputs an AC voltage for one phase will be described here. The pulse signal generation circuit 104 has an oscillator that outputs a pulse signal A + that operates in response to a control signal (not shown) and an A− that is 180 degrees out of phase. In addition, it is composed of a switching circuit (H-bridge circuit) that outputs an AC voltage by controlling the switching element on and off by this pulse signal. A DC-DC converter circuit (not shown) that supplies DC power is connected to the switching circuit, and a rectangular AC voltage pulse is generated by on / off operation. The rectangular pulse signal is adjusted by PWM (pulse width modulation) control so that the pulse width (pulse duty) can obtain a desired AC voltage amplitude. The pulse width is set according to the control signal.

The AC voltage output from the switching circuit is boosted to a desired voltage by forming the capacitance 106 of the piezoelectric element and the resonance circuit 105 by the coupling inductor 101 having the opposite polarity and the boosting transformer 102. The opposite polarity means that the two inductors function to strengthen each other's magnetic flux when a current of opposite phase flows. The polarity of the transformer 102 may be either. The SIN wavy AC voltage boosted by the step-up transformer 102 is applied to the piezoelectric element 103. The vibration type motor can control the speed by the frequency, amplitude, phase difference, etc. of the AC voltage applied to the piezoelectric element 103.

The equivalent circuit of the piezoelectric element 103 will be described. The equivalent circuit of the piezoelectric element 103 includes an RLC series circuit (equivalent coil 107 having a self-inductance Lm, an equivalent capacitor 108 having a capacitance Cm, and an equivalent resistance 109 having a resistance value Rm) of the mechanical vibration portion of the vibrating body. In addition, it is composed of a capacitor 106 as an intrinsic capacitance Cd of the piezoelectric element 103 connected in parallel to this RLC series circuit. The resonance frequency fm of the vibrating body is determined by Lm and Cm. The electric resonance frequency fe of the resonance circuit 105 is determined by the step-up transformer 102, the coupling inductor 101, and the capacitance Cd.

Here, the coupling inductor 101 used in the present invention will be described in detail. The coupling inductor 101 is an inductor in which a first inductor 101a and a second inductor 101b are magnetically coupled. It is desirable that the two inductors have equivalent inductances, but the same effect can be obtained as long as they are within the range of general element variation of ± 30%. In the present invention, the coupling inductor is configured so that the two inductors act as opposite polarities. When driving a vibration type motor, a switching operation is performed by A + pulse and A-pulse having different phases of 180 degrees, and a current of opposite phase flows through the first inductor 101a and the second inductor 101b. For example, when the A + pulse is High and the A-pulse is Low, a current flows from the power supply to the primary side of the transformer via the first inductor 101a. Then, the current returns to the second inductor 101b via the transformer primary winding 102a and operates so as to flow to the ground side. Therefore, a current of opposite phase flows through the first and second inductors while the vibration type motor is being driven. At that time, since the coupling inductor 101 is connected so as to strengthen each other's magnetic flux, the total value (series inductance) of the inductances of 101a and 101b acts as a resonance circuit. With this configuration, magnetic energy is generated so as to stabilize the mechanical arm current flowing through the capacitance of the piezoelectric element, so even if the mechanical arm current flows through the vibration type motor, the resonance characteristics of the circuit are not easily affected and the impedance. A resonance circuit that is resistant to fluctuations can be formed. Further, since the time derivative of the reverse phase current becomes small due to the mutual induction action due to the magnetic coupling of the inductor, the surge current generated in the switching operation can be reduced. As a result, the waveform distortion of the drive current and the drive voltage can be reduced, and the vibration type motor can be driven efficiently. Further, along with the reduction of the time derivative of the anti-phase current, the magnetic flux generated by the in-phase current cancels each other in the coupling inductor, so that the effect of reducing the magnetic noise leaking to the outside can be obtained.

That is, the induced current generated in the second inductor 101b generated by the magnetic flux generated by the current flowing in the first inductor 101a acts to further promote the current flowing in the second inductor 101b.

If the coupling inductor is connected so as to operate in the opposite direction to the present invention, the performance of the vibration type motor is significantly impaired. That is, it is a coupled inductor of the same polarity connected so as to generate a magnetic flux of the same phase when a current of the same phase flows through the two inductors. In this case, the magnetic fluxes generated in the reverse-phase current cancel each other out, so that the inductance becomes invalid, the resonance characteristics of the circuit are disrupted, the distortion of the current and voltage waveforms increases, and the power increases.

The frequency characteristics of the AC voltage output from the resonant circuit can be calculated from the following equation. The electric resonance frequency fe of the resonance circuit is calculated by the equation 1-1.

Here, L is the inductance calculated by Equation 1-2, N is the winding ratio of the step-up transformer 102, and Cd is the capacitance 106 of the piezoelectric element.

L is calculated using Lcp1, Lcp2, and Ltr1. Lcp1 is the inductance of the first inductor 101a, and Lcp2 is the inductance of the second inductor 101b. In this embodiment, the inductances of 101a and 101b are both 4.7 μH. Ltr1 indicates the inductance of the transformer primary winding coil, which is 30 μH. The transformer winding ratio N is 16 times, and the capacitance Cd is 0.5 nF. The power supply is 3V, and an AC voltage of around 120Vpp is output.

When an alternating current of 75 kHz or more and 110 kHz or less flows through the first inductor and the second inductor, it is suitable as a drive frequency band of the vibration type motor. More preferably, it is operated between 87 and 95 kHz. Here, the resonance frequency fm of the vibrating body is 86 kHz. From the above calculation formula, the electric resonance frequency fe is 160 kHz.

FIG. 8 is a diagram showing a timing chart of a pulse signal output from an oscillator in the embodiment of the present invention. FIG. 8A shows a two-phase AC pulse signal output from the oscillator. The oscillator generates an A-phase pulse signal, an A-phase inversion pulse signal, a B-phase pulse signal, and a B-phase inversion pulse signal according to the phase difference, frequency, and pulse width information output from the control calculation unit 112. FIG. 8B shows the time change of the A-phase and B-phase pulse signals when the pulse width is 50%. From t to t4 is one cycle of the frequency for driving the vibrating actuator. The pulse of each phase is output at the Hi level for a time corresponding to 50% of the period. When the phase difference is set to +90 degrees, the pulse rise of each phase is output so as to be shifted by t0 and t1.

FIG. 9 shows the results of measuring the arrival speed and the average power of the vibrating motor using the phase difference of the two-phase AC signals as operating parameters, and compares the results with the present invention and the conventional drive circuit. .. FIG. 9A shows the phase difference on the horizontal axis, the motor speed (left) and the circuit power consumption (right) on the vertical axis. In the range of the phase difference of 0 ° to 180 °, open drive was performed at 10 ° intervals, and the average speed and average power from the start to 10 ms later were calculated. The drive frequency is fixed at 93 kHz. In the phase difference range of 0 to 90 ° used for control, the drive circuit of the present invention tends to have a high motor speed and a low electric power. FIG. 9B shows the motor speed on the horizontal axis and the circuit power consumption on the vertical axis. The present invention has lower power when compared at the same speed. That is, it can be seen that the drive efficiency of the vibration type motor is improved. FIG. 7 shows the configuration of the conventional drive circuit used for comparison. As shown in the figure, the conventional circuit has a configuration in which one inductor 110 is connected in series on the primary side of the step-up transformer 102. The inductance of the inductor 110 is 10 μH, which is set to a value substantially equal to the series inductance value of the two inductors of the coupled inductor 101 of the present invention. This is because the electric resonance frequencies of both resonance circuits are aligned and compared.

FIG. 10 shows the measurement results of the voltage waveform, the current waveform, and the current differential waveform when the vibration type motor is driven with a phase difference of 90 degrees between the two-phase AC signals, and is compared between the present invention and the conventional drive circuit. It was done. It can be seen that the results of the present invention show that the waveform distortion is reduced for both the voltage waveform (first stage) and the current waveform (second stage). This is because magnetic energy is generated so as to stabilize the electric arm current flowing through the capacitance of the piezoelectric element, so that the resonance characteristics of the circuit are not easily affected even if the mechanical arm current flows through the vibration type motor. That is, it can be said that it is a resonance circuit that is resistant to changes in resonance characteristics that occur when driving a vibration motor. Further, when a reverse-phase current flows through the two inductors, the time derivative component of the current can be reduced by the magnetic mutual induction action. The current differential waveform (third stage) has a correlation with the magnetic noise leaking to the outside, and since the peak value is reduced in the present invention, the effect of reducing the magnetic noise can also be obtained.

FIG. 12 compares the control results for the step signal in the drive circuit of the present invention with the conventional circuit. The position feedback control of the vibrating motor was performed so as to follow a step signal (command value) having a minute amplitude of 2 μm. The horizontal axis shows time, and the vertical axis shows position (left) and phase difference (right). FIG. 12A is the result of the conventional circuit, and FIG. 12B is the result of the drive circuit of the present invention. In the conventional circuit, it takes 46 ms for the actual position to reach the command value. The phase difference at that time exceeds 15 °, which means that the vibrating motor did not move until then. On the other hand, the present invention is started in 22 ms, and the response time is shortened. The reason is that the driving performance of the vibrating motor is improved in the region where the phase difference is small, and the phase difference at the time of response is 10 ° or less. Since the feed vibration is small in the region where the phase difference is small, the drive voltage applied to the piezoelectric element has a small waveform distortion, and the drive performance can be improved by the resonance circuit which is not easily affected by the fluctuation of the vibration type motor.

The above-described embodiment of the present invention is a switching circuit driven by a full bridge, but other switching circuits may be used. For example, the effect of the present invention can be obtained by using a switching circuit driven by a half bridge as shown in FIG. In the figure, the switching circuit 501 is configured to perform half-bridge drive. A charge charging capacitor 503 is connected between the coupling inductor 101b and ground, and an AC voltage corresponding to the power supply voltage is applied to the primary side of the step-up transformer 102.

Although the example in which the control device for the vibration type motor of this embodiment is used for driving a lens for autofocus of an image pickup device has been described, the application example of the present invention is not limited to this. For example, it can also be used to drive a lens holder for moving a zoom lens. Therefore, the control device of the present invention can be mounted on an interchangeable lens in addition to the image pickup device for driving the lens. It can also be used to drive an image sensor, and can also be used to drive a lens or an image sensor during image stabilization. It can also be applied to linear drive and rotary drive of surveillance camera lenses and interchangeable lenses.

Further, as a general-purpose actuator, it is possible to provide an electronic device including a member and the above-mentioned vibration type driving device for driving the member.

An example of another resonance circuit in the driving device of the vibration type motor of this invention is shown.

FIG. 6 shows a circuit in which the resonance circuit is composed of only the coupling inductor 101, and no step-up transformer is used. The electrical resonance circuit is formed by the inductance of the coupling inductor and the capacitance 106 of the piezoelectric element. Even if the resonance circuit of this embodiment is used, the waveform distortion of the drive current and the drive voltage can be reduced, and the vibration type motor can be driven efficiently.

The frequency characteristics of the AC voltage output by the resonant circuit can be calculated from the following equation. The electric resonance frequency fe of the resonance circuit is calculated by Equation 2-1.

Here, Lcp1 is the inductance of the first inductor 101a, and Lcp2 is the inductance of the second inductor 101b. Cd is the capacitance 106 of the piezoelectric element. In this embodiment, the inductances of 101a and 101b are both 15 μH, and the series inductance is 30 μH. The capacitance Cd is 33 nF. The power supply is 10V, and an AC voltage of around 30Vpp is output.

The drive frequency is operated between 87 and 95 kHz. Here, the resonance frequency fm of the vibrating body is 86 kHz. From the above calculation formula, the electric resonance frequency fe is 160 kHz.

FIG. 11 shows an example of a drive circuit in which two surface-mounted inductors are magnetically coupled by arranging them so as to face each other as another embodiment of the present invention. Surface-mounted inductors are mounted on the front and back surfaces of the board, and are connected so that they have opposite polarities by arranging them facing each other with the board sandwiched between them. A current of opposite phase flows through the two terminals on the transformer connection side, and the magnetic fluxes generated in the two inductors at that time strengthen each other, so that the series inductance functions as a resonance coil.

If the two inductors forming the resonant circuit are magnetically coupled as in the present embodiment, the effect of the present invention can be obtained in the same manner.

As described above, according to the present invention, it is possible to realize a resonance circuit capable of efficiently driving a vibration type motor.

1 Vibrator 2 Contact 20 Vibrating drive device 21 Control device 23 Vibration type motor 24 Position sensor 110 Control unit 120 Drive circuit 104 Pulse signal generation circuit 105 Resonance circuit 103 Piezoelectric element 106 Capacitance of piezoelectric element Cd
107 Equivalent coil with self-inductance Lm 108 Equivalent capacitor with capacitance Cm 109 Equivalent resistance with resistance value Rm

Claims (10)

A vibrating body having an electric-mechanical energy conversion element and an elastic body,
With the contact body in contact with the vibrating body,
It comprises a first and second inductors of opposite polarity that are magnetically coupled to each other and are arranged so that the magnetic flux generated by the flowing current strengthens each other.
A vibration type drive device in which a resonance circuit is formed by the first inductor, the second inductor, and the electric-mechanical energy conversion element. It also has a step-up transformer,
The first inductor, on one end side of the primary winding of the step-up transformer,
A second inductor, is connected to the other end side,
The vibration type drive device according to claim 1, wherein the electric-mechanical energy conversion element is connected to one end side and the other end side of the secondary winding of the step-up transformer. The vibration type drive device according to claim 1, wherein a first inductor is connected to one end of the electric-mechanical energy conversion element, and a second inductor is connected to the other end. The vibration type drive device according to any one of claims 1 to 3, wherein the series inductance of the first inductor and the second inductor forms a resonance circuit with the capacitance of the conversion element. The vibration according to any one of claims 1 to 4, wherein an alternating current having a frequency of 75 kHz or more and 110 kHz or less flows through the first inductor and the second inductor to drive a vibration type motor. Mold drive. The vibration type drive device according to any one of claims 1 to 5, wherein the inductance values of the first inductor and the second inductor are in the range of ± 30%. The vibration type drive device according to claim 6, wherein the inductance values of the first inductor and the second inductor are equivalent. The vibration type drive device according to any one of claims 1 to 7, wherein magnetic energy of opposite phase is generated when a current of the same phase flows through the first inductor and the second inductor. With the lens
A lens barrel comprising the vibration-type drive device according to any one of claims 1 to 8, which drives a lens holding member that holds the lens. Members and
An electronic device comprising the vibration type driving device according to any one of claims 1 to 8 for driving the member.

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