JP2021197864A - Vibration type actuator driving device, driving method, and program - Google Patents

Abstract

To provide a vibration type actuator driving device capable of reducing the power consumption of a device by appropriately controlling a vibration type actuator according to the usage condition of the device.SOLUTION: A vibration type actuator driving device (1) drives a unit to be driven (2). The vibration type actuator driving device (1) has a plurality of vibrators (5, 6), at least one mover (7, 8), driving circuits (9, 10) for driving the plurality of vibrators, and control means (12), which controls the driving circuits on the basis of a load in moving the unit to be driven.SELECTED DRAWING: Figure 1

Description

The present invention relates to a drive device for a vibration type actuator and a control method thereof, and more particularly to a drive device for a vibration type actuator used for driving a device such as an interchangeable lens for a camera or a robot hand.

An interchangeable lens for a camera that drives a focus lens by using a vibration type actuator that obtains a driving force by applying an AC voltage to an electric-mechanical energy conversion element has been proposed. A large driving force is required to move a focus lens having a large mass. Patent Document 1 discloses a driving device for a vibrating actuator configured to transmit the driving force of a plurality of vibrators to the same driven unit in order to obtain a large driving force.

Japanese Unexamined Patent Publication No. 2018-68112

In the drive device disclosed in Patent Document 1, in order to move the mover at a predetermined speed, substantially the same vibration is excited to a plurality of oscillators. For example, when the mover is driven at a speed v1, if the electric power consumed when one oscillator is used is w1, the electric power consumed when two oscillators are used is about twice the electric power w1. It becomes 2w1. In this way, the oscillating actuator consumes power depending on the moving speed, that is, the driving frequency.

Therefore, in the vibration type actuator disclosed in Patent Document 1, when the driven portion is driven at a predetermined speed, substantially the same vibration is always excited to a plurality of oscillators regardless of the load applied to the driven portion. The power consumption increases by the number of oscillators used.

Therefore, the present invention provides a drive device, a drive method, and a program for a vibrating actuator that can reduce the power consumption of the device by appropriately controlling the vibrating actuator according to the usage status of the device. With the goal.

The driving device for a vibrating actuator as one aspect of the present invention is a driving device for a vibrating actuator that drives a driven portion, and includes a plurality of vibrators, at least one mover, and the plurality of vibrators. It has a drive circuit to be driven and a control means for controlling the drive circuit based on a load when moving the driven unit.

Other objects and features of the present invention will be described in the following examples.

INDUSTRIAL APPLICABILITY According to the present invention, a drive device, a drive method, and a program for a vibrating actuator capable of reducing the power consumption of the device by appropriately controlling the vibrating actuator according to the usage status of the device are provided. be able to.

It is a block diagram of the interchangeable lens provided with the vibration type actuator in Example 1. FIG. It is a block diagram of the focus lens group moving mechanism and the vibration type actuator in Example 1. FIG. It is explanatory drawing of the driving principle of the vibration type actuator in each Example. It is a flowchart which shows the operation of the vibration type actuator in each Example. It is a flowchart of the subroutine which calculates the load of the drive target in each embodiment. It is a figure which shows the relationship between the frequency, the speed and the electric power when the vibration type actuator is used in each Example. It is a block diagram of the interchangeable lens provided with the vibration type actuator in Example 2. FIG. It is a block diagram of the focus lens group moving mechanism and the vibration type actuator in Example 2. FIG.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

First, with reference to FIGS. 1 and 2, a driving device for a vibration type actuator according to the first embodiment of the present invention and an interchangeable lens provided with the driving device will be described. FIG. 1 is a block diagram of an interchangeable lens (lens device) 1 provided with a vibration type actuator. FIG. 2 is a configuration diagram of a focus lens group moving mechanism and a vibration type actuator.

The interchangeable lens 1 includes a focus lens group 2, a guide shaft 3, 4, a vibrator 5, 6, a mover 7, 8, a drive circuit 9, 10, a power supply unit 11, a lens microcomputer 12, a position sensor 13, an acceleration sensor 14, and so on. And has a temperature sensor 15. The focus lens group (driven unit) 2 has an optical system 21 for adjusting the focus. Further, the focus lens group 2 has a focus lens holding cylinder 22 for holding the optical system 21. The focus lens holding cylinder 22 engages with the guide shafts 3 and 4 and is guided straight ahead.

The movers 7 and 8 are fixed (connected) to the focus lens holding cylinder 22. In this embodiment, the movers 7 and 8 are directly fixed to the focus lens holding cylinder 22, but the moving elements 7 and 8 are not limited thereto. For example, the focus lens holding cylinder 22 may be configured to move as the movers 7 and 8 move between the movers 7 and 8 and the focus lens holding cylinder 22 via a component. The guide shaft 3 guides the focus lens holding cylinder 22 in a straight line. The guide shaft 4 regulates the rotation of the focus lens holding cylinder 22 around the optical axis (rotation around the optical axis O).

The vibrator 5 includes a piezoelectric element 51 and an elastic body 52. Similarly, the vibrator 6 includes a piezoelectric element 61 and an elastic body 62. The mover 7 is in pressure contact with the vibrator 5 by a pressure mechanism (not shown). Similarly, the mover 8 is in pressure contact with the vibrator 6 by a pressure mechanism (not shown).

The drive circuits 9 and 10 include a booster circuit using a transformer, a coil, or the like. The drive circuits 9 and 10 perform a switching operation at the timing of the pulse signal sent from the pulse generation unit 16 and the pulse generation unit 17 of the lens microcomputer 12, and obtain a desired DC voltage (DC voltage) supplied from the power supply unit 11. It boosts to a voltage and outputs a substantially sine wave AC voltage. The power supply unit 11 supplies a DC voltage to the drive circuits 9 and 10.

The lens microcomputer 12 controls the components in the interchangeable lens 1. The lens microcomputer 12 includes a pulse generation unit 16, a pulse generation unit 17, a PID control unit 18, a storage unit 19, and a load calculation unit 20. The lens microcomputer 12 is electrically connected to the position sensor 13, the acceleration sensor 14, and the temperature sensor 15.

The position sensor 13 detects the position of the focus lens group 2. The position sensor 13 is an optical encoder that reads the reflection pattern of the reflection type scale attached to the focus lens group 2. However, this embodiment is not limited to this, and the position sensor 13 may be configured by a magnetic scale and a magnetic sensor. The position sensor 13 outputs a voltage signal according to the position of the focus lens group 2. The lens microcomputer 12 acquires a voltage signal output by the position sensor 13 and converts it into a position signal.

The acceleration sensor 14 outputs a voltage signal according to the acceleration applied to the interchangeable lens 1 (gravitational acceleration when stationary). Thereby, the direction in which the interchangeable lens 1 is facing, that is, the angle formed by the focus lens group 2 and the ground can be detected. The lens microcomputer 12 acquires the voltage signal output by the acceleration sensor 14 and converts it into an angle formed by the optical axis O of the interchangeable lens 1 and the ground.

The temperature sensor 15 outputs a voltage signal according to the temperature inside the interchangeable lens 1 (that is, the temperature of the outside air). The lens microcomputer 12 acquires the voltage signal output by the temperature sensor 15 and converts it into the temperature inside the interchangeable lens 1.

The pulse generation units 16 and 17 generate pulse signals having a predetermined phase difference and frequency for vibrating the vibrators 5 and 6 based on the control amount (phase difference, frequency) sent from the PID control unit 18. The pulse signal is sent to the drive circuits 9 and 10, respectively.

The PID control unit 18 calculates the position deviation based on the target position commanded by a camera or an operation unit (not shown) and the current position of the focus lens group 2 detected by the position sensor 13. Then, the PID control unit 18 appropriately vibrates the vibrators 5 and 6 based on the position deviation, calculates the control amount (phase difference and frequency) for moving the focus lens group 2, and pulses the control amount. It is sent to the generators 16 and 17.

The storage unit 19 is, for example, a rewritable non-volatile memory. The storage unit 19 stores control data for controlling the components in the interchangeable lens 1. The control data stored in the storage unit 19 is read out by the lens microcomputer 12 as needed. The load calculation unit 20 estimates the load applied when the focus lens group 2 is moved from the acceleration sensor 14 and the temperature sensor 15 (corresponding to the force required for the movement of the focus lens group 2). The details will be described later.

Next, the driving principle of the vibration type actuator will be described with reference to FIG. FIG. 3A is a perspective view showing a schematic configuration of a vibration type actuator including the vibrator 5 and the mover 7. FIG. 3B is an explanatory diagram of an electrode pattern and a polarization region formed on the piezoelectric element 51. FIG. 3C is an explanatory diagram of the first vibration mode excited by the vibrator 5. FIG. 3D is an explanatory diagram of the second vibration mode excited by the vibrator 5. Since the same applies to the vibration type actuator provided with the vibrator 6 and the mover 8, the description thereof will be omitted.

The vibrator 5 includes a piezoelectric element 51 and an elastic body 52. The piezoelectric element 51 and the elastic body 52 are adhesively fixed. The oscillator 5 is fixed to a fixing means (not shown), and the mover 7 moves in the moving direction indicated by the arrow in FIG. 3 (a). The mover 7 may be fixed and the vibrator 5 may be moved. In that case, the oscillator 5 is connected to the focus lens group 2 which is the driven unit.

The elastic body 52 is made of, for example, a stainless steel thin plate-shaped member. A protrusion 52a is integrally formed on the surface of the elastic body 52 on the mover 7 side. The vibrator 5 and the mover 7 are in pressure contact with each other on the upper surface of the protrusion 52a in the Z direction indicated by the arrow in FIG. 3 (c) by a pressure means (not shown). The piezoelectric element 51 is formed with electrode regions 511 and 512 divided into two equal parts in the X direction connecting the two protrusions 52a, and the polarization directions in each electrode region are the same direction (+). Of the two electrode regions 511 and 512 of the piezoelectric element 51, the AC voltage VB is applied to the right electrode region 512 in FIG. 3B, and the AC voltage VA is applied to the left electrode region 511.

When the AC voltages VB and VA are set to a frequency near the resonance frequency of the first vibration mode and have the same phase, vibration in the first vibration mode is generated in the vibrator 5. In the first vibration mode, as shown in FIG. 3C, the vibration is performed in the Z direction, which is the protrusion direction of the protrusion 52a, and the driving force for moving the mover 7 in the movement direction of the mover 7 is applied. Does not occur. The vibration in the first vibration mode is called "push-up vibration".

Assuming that the AC voltages VB and VA are frequencies near the resonance frequency of the second vibration mode and the phase is shifted by 180 °, the vibrator 5 generates vibration in the second vibration mode. In the second vibration mode, as shown in FIG. 3D, the protrusion 52a vibrates in the X direction and generates a driving force for moving the mover 7 in the moving direction of the mover 7. The vibration in the second vibration mode is called "feed vibration".

By applying an AC voltage having a frequency close to each resonance frequency of the first vibration mode and the second vibration mode to the electrode of the piezoelectric element 51, it is possible to excite the vibration in which the push-up vibration and the feed vibration are combined. .. By combining the push-up vibration and the feed vibration, the protrusion 52a makes an elliptical motion in the Z-X plane, and the mover 7 in pressure contact moves in the X direction due to the elliptical motion. ..

Next, the operation of moving the focus lens group 2 of the interchangeable lens 1 (the operation of the vibration actuator) will be described with reference to FIGS. 4 and 5. FIG. 4 is a flowchart showing an operation of moving the focus lens group 2. FIG. 5 is a flowchart of a subroutine that calculates a load L when moving the focus lens group 2. Each step of FIGS. 4 and 5 is mainly executed by each part of the lens microcomputer 12.

First, in step S1, the lens microcomputer 12 determines whether or not there is a position command (drive command) from the camera or the operation unit. If there is no position command (drive command), the determination in step S1 is repeated. On the other hand, if there is a position command (drive command), the process proceeds to step S2.

In step S2, the lens microcomputer 12 acquires the current position of the focus lens group 2 from the position sensor 13. Subsequently, in step S3, the PID control unit 18 in the lens microcomputer 12 calculates the position deviation based on the position commanded in step S1 and the current position acquired in step S2. Then, the PID control unit 18 calculates the control amount (phase difference, frequency) based on the position deviation.

Subsequently, in step S4, the load calculation unit 20 of the lens microcomputer 12 starts a subroutine that calculates the load L applied when the focus lens group 2 is moved. Here, with reference to FIG. 5, a subroutine for calculating the load L applied when moving the focus lens group 2 will be described.

First, in step S41, the lens microcomputer 12 acquires a voltage signal from the acceleration sensor 14 and calculates an angle A between the moving direction of the focus lens group 2 and the ground. Subsequently, in step S42, the lens microcomputer 12 acquires a voltage signal from the temperature sensor 15 and calculates the temperature (outside air temperature) T of the environment to which the interchangeable lens 1 is exposed.

Subsequently, in step S43, when the load calculation unit 20 in the lens microcomputer 12 moves the focus lens group 2 based on the angle A obtained in step S41 and the temperature T obtained in step S42. The load L of is calculated. After that, the program returns to the original program (to step S5 in FIG. 4). The load L can be expressed as a function of the angle A formed by the moving direction of the focus lens group 2 and the ground and the temperature T of the environment to which the interchangeable lens 1 is exposed. For example, when moving in a direction against gravity, a larger driving force is required. Further, at low temperatures, a large driving force is required due to changes in characteristics such as grease.

Therefore, the load L can be expressed as a function of the angle A formed by the moving direction of the focus lens group 2 and the ground and the temperature T of the environment to which the interchangeable lens 1 is exposed. Functions are derived experimentally or theoretically in the process of developing a product. A look-up table may be used instead of the function. In this embodiment, the load L is estimated based on the information obtained from the two sensors, but any number of factors that affect the load L may be considered. For example, the load L may be estimated by calculating the inertial force from the moving acceleration.

In step S5 of FIG. 4, the lens microcomputer 12 reads out the load threshold value LT stored in the storage unit 19. The load threshold LT is set to be equal to or greater than the driving force that can be generated by the pair of oscillators 5 and the mover 7, or the combination of the pair of oscillators 6 and the mover 8. Then, the lens microcomputer 12 determines whether or not the load L calculated in step S4 is larger than the load threshold value LT.

When the load L is larger than the load threshold LT, it is determined that it is necessary to generate a driving force in the pair of oscillators 5 and the mover 7 and the oscillator 6 and the mover 8 in order to move the focus lens group 2. Then, the process proceeds to step S6. In step S6, the lens microcomputer 12 sends the control amount (phase difference θd and frequency Fd) calculated in step S3 to the pulse generation units 16 and 17. Subsequently, in step S7, the pulse generating units 16 and 17 send pulse signals to the drive circuits 9 and 10, respectively. The pulse signal sent from the pulse generation unit 16 and the pulse generation unit 17 is boosted by the drive circuit 9 and the drive circuit 10, and outputs a substantially sinusoidal AC voltage. The output AC voltage is applied to the piezoelectric element 51 of the vibrator 5 and the piezoelectric element 61 of the vibrator 6, and the vibrators 5 and 6 start to vibrate.

On the other hand, when the load L is smaller than the load threshold LT in step S5, it is determined that the driving force should be generated only by the pair of oscillators 5 and the mover 7 in order to move the focus lens group 2. The process proceeds to step S8. In step S8, the lens microcomputer 12 sends the control amount (phase difference θd and frequency Fd) calculated in step S3 to one pulse generating unit 16, and generates the other pulse with a phase difference of 0 ° and a predetermined frequency Fs. Send to department 17. It should be noted that θd> 0 and Fd <Fs. Subsequently, in step S9, the pulse generating units 16 and 17 send pulse signals to the drive circuits 9 and 10, respectively. The pulse signals sent from the pulse generation units 16 and 17 are boosted by the drive circuits 9 and 10, respectively, and a substantially sinusoidal AC voltage is output. The output AC voltage is applied to the piezoelectric element 51 of the vibrator 5 and the piezoelectric element 61 of the vibrator 6, and the vibrators 5 and 6 start to vibrate, respectively.

When the load L is larger than the load threshold LT, the vibrators 5 and 6 have vibrations (that is, movement of the mover 7) in which substantially the same push-up vibration and feed vibration for moving the focus lens group 2 are combined. Vibration) in which a driving force is generated in the direction is excited. The focus lens group 2 moves in the direction along the optical axis O (optical axis direction) due to the resultant force of the driving force generated by the vibrator 5 and the mover 7 and the driving force generated by the vibrator 6 and the mover 8. do.

On the other hand, when the load L is smaller than the load threshold LT, the vibrator 5 is driven in the movement direction of the mover 7 by combining the push-up vibration and the feed vibration for moving the focus lens group 2. Vibration that generates force) is excited. The focus lens group 2 moves in the optical axis direction only by the driving force generated by the vibrator 5 and the mover 7. On the other hand, since an AC voltage having a phase difference of 0 ° is applied to the vibrator 6, push-up vibration (that is, vibration in which no driving force is generated in the driving direction) is excited. By vibrating in this way, the frictional force acting between the protrusion 62a of the elastic body 62 of the vibrator 6 and the driven portion (moving element 8) is made substantially 0, and the vibrator 5 and the moving element 7 are generated. It is configured so as not to interfere with the driving force.

Next, the effect of this embodiment will be described with reference to FIG. FIG. 6 is a diagram showing the relationship between frequency, speed, and electric power when a vibration type actuator is used. FIG. 6 shows the speed and power consumption (power consumption) of a focus lens group when an AC voltage is applied to an interchangeable lens having the same configuration as that of the present embodiment while changing the frequency with a phase difference of 90 °. Is shown. In FIG. 6, the horizontal axis represents frequency, and the vertical axis represents speed and power, respectively.

In a situation where the interchangeable lens 1 is used for shooting in a horizontal position and in a normal temperature environment (a situation where the load is light), the phase difference θ = 90 ° between the oscillator 5 and the oscillator 6 and the AC voltage of the drive frequency Fd as in the past. When driving by applying the above, the power Wp consumed at the speed v1 is Wp≈W1 + W1.

On the other hand, as in this embodiment, the oscillator 5 is driven by applying an AC voltage having a phase difference θ = 90 ° and a drive frequency Fd, and the oscillator 6 has a phase difference of 0 ° and a drive frequency Fs (> Fd). When only the push-up vibration is excited by applying an AC voltage, the result is as follows. The power consumption of the oscillator 5 and the mover 7 is W1, and the power consumption of the oscillator 6 and the mover 8 is about W0 (if the frequencies are the same, the phase difference is 90 ° and the phase difference is 0). There is virtually no power difference at °). Therefore, the total power consumption Wf of the vibrating actuator composed of the two pairs of oscillators and the mover is Wf≈W1 + W0. Here, since Fd <Fs, W1> W0. Therefore, Wp> Wf, and power saving can be realized.

As described above, in the present embodiment, the driving device (interchangeable lens 1) of the vibration type actuator that drives the driven portion includes a plurality of vibrators 5 and 6, a plurality of movers 7 and 8, and a plurality of vibrations. It has drive circuits 9 and 10 for driving the child, and control means (lens microcomputer 12). The control means controls the drive circuit based on the load L when moving the driven unit.

Preferably, the plurality of oscillators are arranged so as to be able to generate a driving force in the moving direction of the mover. More preferably, the control means controls the drive circuit to excite vibrations that do not generate a driving force for at least one of the plurality of oscillators based on the load.

Preferably, the plurality of oscillators include a first oscillator (oscillator 5) and a second oscillator (oscillator 6). When the load is larger than a predetermined load (load threshold LT) (L> LT), the control means so as to excite the vibration that generates the driving force for the first oscillator and the second oscillator. Control the drive circuit. On the other hand, when the load is smaller than a predetermined load (L <LT), the control means excites a vibration that generates a driving force with respect to the first vibrator, and applies the driving force to the second vibrator. The drive circuit is controlled to excite vibrations that do not occur.

Preferably, the control means has an estimation means (load calculation unit 20) for estimating the load. More preferably, the estimation means estimates the load based on signals from at least one of the position sensor 13, the acceleration sensor 14, or the temperature sensor 15.

According to the interchangeable lens 1 (driving device of the vibration type actuator) of the present embodiment, it is possible to estimate the load according to the usage conditions and appropriately control a plurality of oscillators. Therefore, it is possible to reduce the power consumption of the interchangeable lens 1.

Next, with reference to FIGS. 7 and 8, the drive device and the interchangeable lens provided with the drive device according to the second embodiment of the present invention will be described. FIG. 7 is a block diagram of an interchangeable lens (lens device) 100 provided with a vibration type actuator. FIG. 8A is a schematic view of the focus lens group moving mechanism and the vibration type actuator. FIG. 8B is a perspective view of the vibration type actuator. In this embodiment, the description of the parts common to the first embodiment will be omitted.

The guide cylinder 30 is formed with three straight guide grooves 70 for guiding the cam follower 60 fixed to the focus lens holding cylinder 22 in the optical axis direction. The cam cylinder 40 is rotatable with respect to the guide cylinder 30 and is supported in a state where movement in the optical axis direction is restricted, and the cam follower 60 fixed to the focus lens holding cylinder 22 moves in the optical axis direction. Three cam grooves 40a for making the cam groove 40a are formed. The cam cylinder 40 is connected to the mover 7, and rotates around the optical axis as the mover 7 rotates.

The cam follower 60 is connected to the focus lens holding cylinder 22. Further, the cam follower 60 is engaged with the cam groove 40a of the cam cylinder 40. When the cam cylinder 40 is rotated, the intersection of the straight guide groove 70 provided in the guide cylinder 30 and the cam groove 40a provided in the cam cylinder 40 moves. When the cam follower 60 fixed to the focus lens holding cylinder 22 engages with this intersection, the focus lens group 2 moves in the optical axis direction.

The vibrator 50 includes a piezoelectric element and an elastic body. The vibrator 50 is in pressure contact with the mover 7 by using a pressure mechanism (not shown). In this embodiment, there are a total of three oscillators 50, but the number of oscillators 50 is not limited to this. The oscillator 50 is connected to the drive circuit 9. The three oscillators 5, 6 and 50 are in pressure contact with the common mover 7. The driving force generated by the vibrators 5, 6, 50 and the mover 7 acts to rotate the mover 7 around the optical axis.

In this embodiment, the driving principle of the vibration type actuator and the operation of moving the focus lens group 2 are the same as those in the first embodiment, and therefore the description thereof will be omitted.

When the load L is larger than the load threshold LT, the vibrators 5, 50, and 6 have vibrations (movement of the mover 7) in which substantially the same push-up vibration and feed vibration for moving the focus lens group 2 are combined. Vibration) in which a driving force is generated in the direction is excited. The focus lens group 2 is formed by the resultant force of the driving force generated by the vibrator 5 and the mover 7, the driving force generated by the vibrator 50 and the mover 7, and the driving force generated by the vibrator 6 and the mover 7. Move in the optical axis direction.

On the other hand, when the load L is smaller than the load threshold LT, the vibrator 5 and the vibrator 50 have vibrations (moving direction of the mover 7) in which the push-up vibration and the feed vibration for moving the focus lens group 2 are combined. Vibration) that generates a driving force is excited. The focus lens group 2 moves in the optical axis direction due to the driving force generated by the vibrator 5 and the mover 7 and the resultant force generated by the vibrator 50 and the mover 7.

On the other hand, since an AC voltage having a phase difference of 0 ° is applied to the vibrator 6, push-up vibration (vibration in which no driving force is generated in the moving direction of the mover 7) is excited. By vibrating in this way, the frictional force acting between the protrusion 62a of the elastic body 62 of the vibrator 6 and the driven portion is made substantially 0, and the vibrator 5 and the mover 7 and the vibrator 50 and the mover 7 are made substantially zero. It is configured so as not to interfere with the driving force generated by.

Next, the effect of this embodiment will be described with reference to FIG. When the interchangeable lens 100 is used in a horizontal position and in a normal temperature environment (when the load is light), an AC voltage with a phase difference of θ = 90 ° and a drive frequency of Fd is applied to the vibrators 5, 50, and 6 as in the conventional case. The power Wp consumed at the speed v1 is Wp≈W1 + W1 + W1.

On the other hand, as in this embodiment, the oscillator 5 and the oscillator 50 are driven by applying an AC voltage having a phase difference θ = 90 ° and a drive frequency Fd, and the oscillator 6 is driven with a phase difference of 0 ° and a drive frequency Fs ( > When an AC voltage of Fd) is applied to excite only the push-up vibration, the result is as follows. The power consumption consumed by the vibrator 5 and the mover 7 and the vibrator 50 and the mover 7 is W1 + W1. The power consumption consumed by the oscillator 6 and the mover 7 is about W0 (if the frequencies are the same, there is substantially no power difference when the phase difference is 90 ° and the phase difference is 0 °). Therefore, the total power consumption of the vibration type actuator is Wf≈W1 + W1 + W0. Here, since Fd <Fs, W1> W0. Therefore, Wp> Wf, and power saving can be realized.

As described above, in the present embodiment, the drive device of the vibration type actuator that drives the driven portion is a drive that drives a plurality of vibrators 5, 50, 6, one mover 7, and a plurality of vibrators. It has circuits 9 and 10 and control means (lens microcomputer 12). The control means controls the drive circuit based on the load L when moving the driven unit. According to the interchangeable lens 100 (driving device of the vibration type actuator) of this embodiment, it is possible to estimate the load according to the usage conditions and appropriately control a plurality of oscillators. Therefore, it is possible to reduce the power consumption of the interchangeable lens 100.

Next, Example 3 of the present invention will be described. In the second embodiment, only one load threshold value LT is provided, but in this embodiment, a plurality of load threshold values LT1 and LT2 (LT1> LT2) are provided.

As a result of step S5 in FIG. 4, when the load L is larger than the load threshold value LT1 (L> LT1), the process proceeds to step S6. In step S6, the lens microcomputer 12 sends the control amount (phase difference θd and frequency Fd) calculated in step S3 to the pulse generation units 16 and 17. As a result, three oscillators 5, 50 and 6 are driven.

On the other hand, as a result of step S5, when the load L is smaller than the load threshold value LT1 and larger than the load threshold value LT2 (LT1> L> LT2), the process proceeds to step S8. In step S8, the lens microcomputer 12 sends the control amount (phase difference θd and frequency Fd) calculated in step S3 to the pulse generation unit 16. Further, the lens microcomputer 12 sends a phase difference of 0 ° and a predetermined frequency Fs to the pulse generation unit 17. As a result, the two oscillators 5 and 50 are driven.

Further, as a result of step S5, when the load L is smaller than the load threshold value LT2 (L <LT2), the process proceeds to step S8. In step S8, the lens microcomputer 12 sends the control amount (phase difference θd and frequency Fd) calculated in step S3 to the pulse generation unit 17. Further, the lens microcomputer 12 sends a phase difference of 0 ° and a predetermined frequency Fs to the pulse generation unit 16. As a result, only one oscillator 6 is driven.

As described above, in the present embodiment, the plurality of vibrators in the drive device of the vibration type actuator are the first vibrator (vibration 5), the second vibrator (vibration 50), and the third vibration. Includes a child (oscillator 6). When the load L is larger than the first load (load threshold value LT1) (L> LT1), the control means has a driving force with respect to the first oscillator, the second oscillator, and the third oscillator. The drive circuit is controlled so as to excite the vibration that generates. Further, when the load is smaller than the first load and larger than the second load (load threshold value LT2) (LT1> L> LT2), the control means refers to the first oscillator and the second oscillator. It excites the vibration that generates the driving force, and excites the vibration that does not generate the driving force to the third oscillator. Further, when the load is smaller than the second load (L <LT2), the control means excites a vibration that generates a driving force with respect to the third oscillator, and the first oscillator and the second oscillator It excites vibrations that do not generate driving force. According to the interchangeable lens 100 (driving device of the vibration type actuator) of this embodiment, it is possible to estimate the load according to the usage conditions and appropriately control a plurality of oscillators. Therefore, it is possible to reduce the power consumption of the interchangeable lens 100.

(Other examples)
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.

According to each embodiment, the drive device, the drive method, and the program of the vibration type actuator capable of reducing the power consumption of the device by appropriately controlling the vibration type actuator according to the usage condition of the device. Can be provided.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these examples, and various modifications and modifications can be made within the scope of the gist thereof.

For example, in each embodiment, the case where the driving device of the vibrating actuator is used for the lens moving mechanism of the interchangeable lens has been described, but the present invention is not limited to this, and the driving device of the vibrating actuator is the driving device of the robot hand. It can also be applied to other devices such as.

5, 6 Oscillator 7, 8 Mover 9, 10 Drive circuit 12 Lens microcomputer (control means)

Claims (11)

It is a drive device for a vibrating actuator that drives a driven unit.
With multiple oscillators,
With at least one mover,
The drive circuit that drives the plurality of oscillators and
A drive device for a vibration type actuator, comprising: a control means for controlling the drive circuit based on a load when the driven portion is moved. The driving device for a vibration type actuator according to claim 1, wherein the plurality of vibrators are arranged so as to be able to generate a driving force in a moving direction of the moving element. The control means is characterized in that the drive circuit is controlled so as to excite vibration that does not generate the driving force for at least one of the plurality of oscillators based on the load. The driving device for the vibration type actuator according to claim 2. The plurality of oscillators include a first oscillator and a second oscillator, and the plurality of oscillators include a first oscillator and a second oscillator.
The control means is
When the load is larger than a predetermined load, the drive circuit is controlled so as to excite the vibration that generates the driving force for the first oscillator and the second oscillator.
When the load is smaller than the predetermined load, the vibration that generates the driving force is excited to the first vibrator, and the vibration that does not generate the driving force is excited to the second vibrator. The drive device for a vibration type actuator according to claim 2 or 3, wherein the drive circuit is controlled so as to be used. The plurality of oscillators include a first oscillator, a second oscillator, and a third oscillator.
The control means is
When the load is larger than the first load, the first oscillator, the second oscillator, and the third oscillator are excited to vibrate to generate the driving force. Control the drive circuit,
When the load is smaller than the first load and larger than the second load, the vibration that generates the driving force is excited to the first vibrator and the second vibrator, and the vibration is excited. The drive circuit is controlled so as to excite the vibration that does not generate the driving force with respect to the third vibrator.
When the load is smaller than the second load, the vibration that generates the driving force is excited to the third vibrator, and the vibration is excited to the first vibrator and the second vibrator. The driving device for a vibration type actuator according to claim 2 or 3, wherein the driving circuit is controlled so as to excite vibration that does not generate a driving force. The driving device for a vibration type actuator according to any one of claims 1 to 5, wherein the control means further includes an estimation means for estimating the load. The driving device for a vibration type actuator according to claim 6, wherein the estimation means estimates the load based on a signal from at least one of a position sensor, an acceleration sensor, or a temperature sensor. The driving device for a vibration type actuator according to any one of claims 1 to 7, wherein the load corresponds to a force required for movement of the driven portion. The driving device for a vibration type actuator according to any one of claims 1 to 8, wherein the driven unit is connected to the mover or the plurality of vibrators. It is a driving method of a vibration type actuator which includes a plurality of vibrators, at least one mover, and a drive circuit for driving the plurality of vibrators to drive a driven unit.
The step of estimating the load when moving the driven unit, and
A method for driving a vibration type actuator, which comprises a step of controlling the drive circuit based on the load. A program comprising causing a computer to execute the driving method of the vibration type actuator according to claim 10.

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