JPH09308273A - Controller of vibrating wave driving device and equipment using the controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a stable driving without installing monitor electrodes or searching for a resonance frequency before driving by providing a means for controlling a frequency signal when an actual driving speed is different from a target one. SOLUTION: In order to control a vibrating motor 9, it is necessary that the frequency of a frequency signal is so adjusted that a desired speed can be obtained at a higher frequency than a resonance frequency and a driving frequency region is so restricted that the frequency may not become lower than the resonance frequency. Therefore, the possible maximum speed is stored for each integrated value of driving time. When a revolutional speed of a motor 9 is higher than the stored maximum speed, the frequency is increased by a predetermined value to lower the speed. By this method, the driving frequency never become lower than the resonance frequency even if the resonance frequency changes with the lapse of time. Furthermore, a driving termination processing is conducted for the motor 9 and an up/down counter 13, a frequency divider/phase shifter 4, and a timer are stopped by the processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates a progressive vibration wave on the surface of a vibrating body by applying a frequency voltage to an electromechanical energy conversion element such as an electrostrictive element or a piezoelectric element, and moves by this vibration wave. The present invention relates to a control device for a vibration wave driving device that drives a body.

[0002]

2. Description of the Related Art In order to efficiently drive a vibration wave motor (vibration wave driving device), it is desirable to drive the motor at or near the mechanical resonance frequency. However, since the resonance frequency fluctuates according to environmental conditions such as temperature, load, and changes over time, if the drive frequency of the vibration wave motor is uniformly defined, it will not be possible to cope with changes in environmental conditions.

In other words, if the drive frequency is specified regardless of the change over time, the drive time was 10 hours or 20 even though the drive could be performed when there was no change over time (driving for only a few minutes). As the time increases, the resonance frequency becomes higher, the drive frequency becomes lower than the resonance frequency, and the number of revolutions (speed) suddenly decreases.

Therefore, for example, Japanese Patent Laid-Open No. 59-156168.
Japanese Patent Publication (Gazette 1) proposes a method of driving a motor at a resonance frequency according to changes in environmental conditions. In this method, first, the frequency of the frequency voltage applied to the vibration wave motor is sequentially changed, and the driving speed at each of the changed frequencies is measured. Then, the measured values are sequentially compared and calculated, the frequency at which the measured value is maximum is stored, and the vibration wave motor is driven at the stored frequency.

Further, Japanese Patent Publication No. 5-14511 (Patent Document 2) is provided with a monitor electrode for detecting a vibration state of a motor, and a resonance frequency is detected by a signal from the electrode and applied to a vibration wave motor. A method of adjusting the frequency of a frequency voltage is disclosed.

[0006]

However, in the method proposed in the above publication 1, the driving for obtaining the resonance frequency must be performed before the vibration wave motor is actually driven at the resonance frequency. Therefore, it takes time to drive at the resonance frequency, and it is necessary to perform the drive for obtaining the resonance frequency every time the environmental condition changes, which causes an inconvenience that power consumption increases.

Further, in the method disclosed in the above-mentioned publication 2, a monitor electrode must be provided separately from the electrode for applying the driving frequency voltage to the vibration wave motor, and the signal from the monitor electrode is further processed. Circuit is required.
For this reason, there is a problem that the structure becomes complicated and the cost increases.

Therefore, a first object of the present invention is to control a vibration wave driving device which can always realize stable driving without providing monitor electrodes and without searching for a resonance frequency before driving. It is to provide a device.

[0009]

In order to achieve the above object, in the first invention of the present application, a frequency signal is applied to the electro-mechanical energy conversion element to excite vibration in the vibrating body. In a control device of a vibration wave driving device that relatively drives a moving body, a time detection unit that detects a time state of the vibration wave driving device and a target drive speed is set according to the time state detected by the time detection unit. When the target speed setting means, speed detecting means for detecting the actual driving speed of the vibration wave driving device, and the target driving speed set by the target speed setting means and the actual driving speed detected by the speed detecting means are different, And a signal control means for controlling the frequency signal.

That is, when the actual drive speed is faster than the target drive speed set according to the elapsed time, the frequency of the frequency signal is increased in the region above the resonance frequency to decrease the speed of the vibration wave drive device. When the drive speed exceeds the target drive speed, it is prohibited to lower the frequency of the frequency signal in the region above the resonance frequency to prevent the speed of the vibration wave drive device from further increasing. Even if the resonance frequency changes, it is possible to always drive in a region higher than the resonance frequency.

In the second invention of the present application, the target drive speed for each aged state is stored in advance, and the target drive speed is selected by an integrated value such as the drive time and the number of times which is an index indicating the aged state. The configuration eliminates the need to perform a drive for searching the resonance frequency before the actual drive and to provide a monitor electrode for detecting the resonance frequency.

In each of the above inventions, the target drive speed is set to a speed higher than the resonance frequency, and stable drive control can be performed with some margin even when the actual drive speed is excessively increased. It is desirable to be able to do so.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a block diagram showing a control device for a vibration wave motor according to a first embodiment of the present invention. In the figure, 1 is a microcomputer, 2
Is a D / A converter. The D / A converter 2 has a function of converting a digital output signal (D / Aout) of the microcomputer 1 into an output voltage.

Reference numeral 3 is a voltage controlled oscillator (VCO), which is a D / A
The frequency voltage corresponding to the output voltage of the converter 2 is output.
A frequency divider / phase shifter 4 divides the frequency voltage of the VCO 3 to
Two rectangular wave frequency voltages (frequency voltage A and frequency voltage B) having a phase difference of / 2 are output.

Power amplifiers 5 and 6 amplify the frequency voltages A and B output from the frequency divider / phase shifter 4 to electric power (voltage and current) suitable for driving the vibration wave motor 9. Reference numerals 7 and 8 are matching coils.

Reference numeral 9 is a vibration wave motor, 9a is a rotor,
9b is a stator. 10 is a pulse plate, and as shown in the figure, a plurality of slits are opened in the radial direction,
It rotates integrally with the rotor 9a of the vibration wave motor 9. The output of the vibration wave motor 9 is transmitted to a film feeding device 21 such as a camera via a power transmission mechanism 20 composed of a gear train or the like, as shown in FIG. 1, and drives this. The output of the vibration wave motor 9 may drive a device other than the film feeding device.

A photo interrupter 11 detects the rotation of the pulse plate 10. Reference numeral 12 is a detection circuit for a signal output from the photo interrupter 11, which amplifies a minute signal from the interrupter 11 and converts it into a digital signal.

Reference numeral 13 is an up / down counter, which counts pulse signals generated by the rotation of the pulse plate 10. A memory circuit 14 stores a program for driving and controlling the vibration wave motor, a data table of the maximum drivable speed (target driving speed) for each number of times of driving, and the like.

Next, each terminal of the microcomputer 1 will be described. DIR1 is an output terminal for instructing the count direction of the up / down counter 13, and outputs an "H" signal when supporting the up direction, and outputs an "L" signal when supporting the down direction.

PULSE IN is an input terminal for the count value of the up / down counter 13. MON is a monitor input terminal that directly receives the output of the detection circuit 12.
RESET is a reset output terminal of the up / down counter 13, and outputs an “H” signal when resetting the counter 13.

CNT EN / DIS is up / down
The counter 13 is an output terminal of a signal for instructing the count enable / disable, and outputs the “H” signal when instructing the count enable and outputs the “L” signal when prohibiting the count.

D / Aout is an output terminal for a digital output signal to the D / A converter 2. Since the DIR 2 switches the rotation direction of the vibration wave motor 9, the phase difference between the frequency voltages A and B applied to the vibration wave motor 9 is 90 °, 270.
This is an output terminal of a signal for giving an instruction to change to the frequency divider / phase shifter 4.

USM EN / DIS is a frequency divider / phase shifter 4
Is an output terminal of a signal for turning ON / OFF the output of, and outputs an “H” signal when turned ON and outputs an “L” signal when turned OFF. ADDRESS is an output terminal of a signal for designating an address of the memory circuit 14, and designates which data of the data in the memory circuit 14 is input to DATA IN described below. DATA IN is an input terminal for the data stored in the address on the memory circuit 14 which is output to the ADDRESS terminal and designated.

Next, the vibration wave motor 9 will be described with reference to FIG. This figure shows the arrangement state of the electrostrictive elements arranged on the back surface of the stator 9b. A _{1 in} Fig. 2
And B ₁ are the first and second electrostrictive element groups arranged on the stator 9b, and have the illustrated phase and polarization relationship, respectively. Each of these electrostrictive element groups may be individually attached to the vibrating body, or may be integrally formed by polarization treatment. Motors A and B shown in FIG. 1 represent drive electrodes for the first and second electrostrictive element groups A ₁ and B ₁ , respectively, and a frequency voltage is applied to the electrode A via an amplifier 5 as well. A frequency voltage is applied to the electrode B via the amplifier 6. As a result, a progressive vibration wave is formed on the back surface of the stator 9b.

FIG. 3 is a flow chart showing the operation of the microcomputer 1 in this embodiment. This flowchart is built in the memory circuit 14, and is executed by the microcomputer 1 when the control of the vibration wave motor 9 enters a drive control routine.

[Step 1] In this step, up
The value of the / down counter 13 is input from the PULSE IN terminal, and the target stop position is calculated from the predetermined drive amount.

[Step 2] In this step, the initial frequency for driving the vibration wave motor 9 is output to the D / Aout terminal. As a result, the D / A converter 2 becomes D / Aou.
The digital voltage value output from the t terminal is converted into an analog voltage and output to the VCO 3. The VCO 3 converts the voltage output from the D / A converter 2 into a frequency and outputs the frequency to the frequency divider / phase shifter 4.

[Step 3] In this step, the drive rotation direction is determined. If it is normal rotation, proceed to step 4,
In the case of reverse rotation, proceed to step 5.

[Step 4] In this step (when the drive rotation direction is forward rotation), "H" is output to the DIR1 terminal to set the up / down counter 13 to the up direction. Further, "H" is output to the DIR2 terminal to set the phase difference between the frequency signals A and B output from the frequency divider / phase shifter 4 to 90 °, and the process proceeds to step 6.

[Step 5] In this step (when the driving rotation direction is reverse rotation), "L" is output to the DIR1 terminal to set the up / down counter 13 to the down direction. Also, "L" is input to the DIR2 terminal.
To output the frequency signals A and B output from the frequency divider / phase shifter 4.
The phase difference is set to 270 ° and the process proceeds to step 6.

[Step 6] In this step, CN
Outputs "H" to the T EN / DIS terminal, and up / dow
The n counter 13 is set to the count enable state.

[Step 7] In this step, US
"H" is output to the MEN / DIS terminal to enable the frequency signals A and B from the frequency divider / phase shifter 4. As a result, the frequency divider / phase shifter 4 outputs signals from A and B depending on the frequency according to the voltage output from the VCO 3 and the phase difference according to the level output from the DIR2 terminal.

Frequency signals A and B output from the frequency divider / phase shifter 4
Is amplified by the power amplifiers 5 and 6 and applied to the vibration wave motor 9 via the matching coils 7 and 8. As a result, the vibration wave motor 9 starts rotating.

[Step 8] In this step, a timer for measuring the driving time of the vibration wave motor is started. The timer stops counting each time the vibration wave motor is stopped, and is used to obtain an integrated value of the driving time of the vibration wave motor.

[Step 9] In this step, the maximum drivable speed data is read from the memory circuit 14 based on the integrated value of the timer.

Here, the characteristic of the rotational speed of the motor with respect to frequency is, as shown in FIG.
In the frequency range higher than that, the rotational speed gradually decreases as the frequency increases, and in the low frequency area, the rotational speed sharply decreases. The frequency at this boundary is the resonance frequency. Then, as shown in the figure, in the vibration wave motor 9, the characteristics with respect to the resonance frequency and the frequency of the rotational speed change with time. As can be seen from this figure, as the driving time increases, the resonance frequency increases and the maximum speed decreases.

As shown in the data table of FIG. 5, the memory circuit 14 has a value (Vm1, which is slightly lower than the original maximum speed (driving speed at the resonance frequency) according to the driving time.
Vm2, Vm3) are stored as a data table. The reason why a slightly lower value is stored instead of the maximum speed is to allow for a margin when the speed is mistakenly increased too much. In the present embodiment, V at each drive time (integrated value) is stored.
It is assumed that m1, Vm2, and Vm3 are the maximum driveable speeds. In this step, the maximum drivable speed is read from the data table of FIG. 5 according to the value of the timer started in step 8.

[Step 10] In this step, u
The actual speed of the motor is detected by calculating the count frequency of the p / down counter 13.

[Step 11] In this step, the maximum drivable speed read in step 9 is compared with the actual motor speed detected in step 10. If the actual motor speed is faster than the maximum drivable speed, Proceed to Step 12, otherwise proceed to Step 13.

[Step 12] In this step (when the actual motor speed is higher than the maximum drivable speed), the drive frequency of the vibration wave motor 9 is increased by a predetermined value to decrease the speed.

[Step 13] In this step, the target stop position calculated in step 2 and the current up / do
The remaining drive amount is calculated based on the value of the wn counter 13.

[Step 14] In this step, it is determined whether or not the remaining drive amount is greater than zero. That is, it is determined whether the remaining drive amount is still present, the target drive amount has already been driven, or whether the vehicle has overrun. If the remaining drive amount is still present, the process proceeds to step 9, otherwise the process proceeds to step 15. move on.

[Step 15] In this step (remaining drive amount ≦ 0, that is, when the target drive amount has been driven or overrun), “L” is output to the USM EN / DIS terminal to perform frequency division / phase shift. The frequency signals A and B of the container 4 are disabled. As a result, the motor 9 stops driving.

[Step 16] In this step, the timer for measuring the drive time of the vibration wave motor 9 is stopped.

[Step 17] In this step, C
Output "L" to NT EN / DIS terminal, and up / do
Set the wn counter 13 to the count disable state,
The drive processing of the motor 9 is completed.

The above operation will be described in summary. In steps 1 to 8, initialization is performed at the time of startup.
Specifically, confirmation of the initial state of the up / down counter 13, output of the initial frequency, determination and setting of the rotation direction,
Start the motor by starting the timer.

In steps 9 to 14, the motor rotation speed is controlled so as not to exceed the maximum drivable speed. These steps are repeatedly executed until the motor 9 reaches the target stop position.

Here, as a control method of the vibration wave motor 9, the frequency of the frequency signal is adjusted so that a desired rotation speed can be obtained at a frequency higher than the resonance frequency, and this frequency is not lower than the resonance frequency. It is necessary to limit the drive frequency range. Since the resonance frequency of the vibration wave motor 9 changes with time as shown in FIG.
If the drive frequency is defined as a drive frequency when there is no change over time, that is, regardless of the change over time, the resonance frequency increases as the drive time increases to 10 hours and 20 hours, and the drive frequency becomes equal to the resonance frequency. There is an inconvenience that the rotation speed decreases and the rotation speed suddenly decreases.

Therefore, in this embodiment, the maximum drivable speed is stored for each integrated value of the driving time, and if the motor rotation speed detected in step 10 is faster than the stored maximum speed, step 12 is performed. The frequency is increased by a predetermined value to reduce the speed. As a result, the drive frequency does not fall below the resonance frequency even if the resonance frequency changes due to aging.

Further, in steps 15 to 17, the drive end processing of the motor is performed, and the operations of the up / down counter 13, the frequency divider / phase shifter 4, and the timer are stopped. By performing the drive control process as described above, it is not necessary to search the resonance frequency of the vibration wave motor before driving or to provide the monitor electrode for monitoring the vibration state of the vibration wave motor, It becomes possible to drive and control the vibration wave motor in a high region.

Although the phase difference between the frequency voltages A and B applied to the vibration wave motor 9 is 90 ° in the present embodiment, the present invention can be applied even if the phase difference is other than 90 °. is there.

In the present embodiment, the case where the vibration wave motor has a ring shape has been described, but the present invention can be applied to motors having other shapes.

Further, in this embodiment, the photo interrupter is used for detecting the rotation of the vibration wave motor, but the present invention is applicable to any other detecting method such as reading the code pattern with a brush. It is possible.

Further, in the present embodiment, D /
The digital value output to the Aout terminal is converted into an analog voltage by the D / A converter 2, and this analog voltage is converted to V
Although the frequency is converted by CO3, the present invention may be applied to other conversion methods and can be applied as long as the frequency can be arbitrarily set.

Further, in the present embodiment, the table of the maximum drivable speed data corresponding to each driving time is set to the driving time 3
Although the data is divided into stages, the present invention can be applied to other stages.

(Second Embodiment) FIG. 6 is an operation flowchart in the control device of the second embodiment of the present invention. The present embodiment is different from the first embodiment only in that step 11 is step 21 and step 12 is step 22, so only different points will be described here.

[Step 21] In this step, the maximum drivable speed read in step 9 is compared with the actual motor speed detected in step 10. If they are equal, the process proceeds to step 13, otherwise, the process proceeds to step 22. Proceed to.

[Step 22] In this step (when the speed of the motor 9 has not reached the maximum drivable speed), the drive frequency of the vibration wave motor 9 is decreased by a predetermined value, and the speed of the motor is increased.

In the above operation, the first embodiment is also performed.
Similar to the embodiment, the maximum drivable speed is read from the data table according to the integrated value of the driving time. Then, if the speed of the motor 9 has not yet reached the maximum speed immediately after starting, the speed of the motor is increased by decreasing the frequency by a predetermined value in step 22.

When the speed of the motor 9 reaches the maximum drivable speed, by bypassing step 22, the shift operation in the direction of lowering the frequency is prohibited to prevent the frequency from exceeding the resonance frequency. ing.

By performing the drive control processing as described above,
Also in the present embodiment, as in the first embodiment, it is not necessary to search the resonance frequency of the vibration wave motor before driving or to provide a monitor electrode for monitoring the vibration state of the vibration wave motor, and it is always a region higher than the resonance frequency. Thus, it becomes possible to drive and control the vibration wave motor.

In this embodiment, the phase difference between the frequency voltages A and B applied to the vibration wave motor 9 is 90 °, but the present invention can be applied even if the phase difference is other than 90 °. is there.

In the present embodiment, the case where the vibration wave motor has a ring shape has been described, but the present invention can be applied to motors having other shapes. Further, in the present embodiment, the photo interrupter is used to detect the rotation of the vibration wave motor, but the present invention can be applied to any other detection method such as reading the code pattern with a brush. is there.

Further, in the present embodiment, the D /
The digital value output to the Aout terminal is converted into an analog voltage by the D / A converter 2, and this analog voltage is converted to VC.
Although the frequency is converted to O3, the present invention may be applied to other conversion methods, and can be applied as long as the frequency can be arbitrarily set.

Further, in the present embodiment, the table of the maximum drivable speed data corresponding to each driving time is set to the driving time 3
Although the data is divided into stages, the present invention can be applied to other stages.

(Third Embodiment) FIG. 7 is a flow chart showing the operation of the control device of the third embodiment of the present invention, showing a case where information on the passage of time is obtained by detecting the number of times the vibration wave motor is driven. There is.

This embodiment differs from the second embodiment in that
Step 8 is Step 41, Step 9 is Step 4
Since only the point 2 is omitted and step 16 is omitted, only the different points will be described here.

[Step 41] In this step, the variable DRVN is incremented. Where the variable DRV
N is a variable that stores the number of times the vibration wave motor 9 is driven, and the number of times of driving can be detected by incrementing this variable each time the vibration wave motor 9 is driven.

[Step 42] In this step, the maximum speed data that can be driven based on the value of the variable DRVN is read from the memory circuit 14.

Here, in this embodiment, the information regarding the passage of time is obtained not by the driving time of the vibration wave motor but by the integrated value of the number of times of driving, and as shown in FIG. 9, the maximum drivable speed according to the number of times of driving is obtained. It has data as a table.

The characteristic of the rotational frequency of the vibration wave motor with respect to the frequency changes depending on the number of times the vibration wave motor is driven, as shown in FIG. As can be seen from the figure, as the driving frequency increases, the resonance frequency increases and the maximum speed decreases. The memory circuit 14 stores values (Vm4, Vm5, Vm6) slightly lower than the maximum speed according to the number of driving as a data table. The reason why a slightly lower value is stored instead of the maximum speed is the same as in the first and second embodiments.

At step 42, the driving frequency of the vibration wave motor 9 is detected by the value of the variable DRVN, and the maximum drivable speed corresponding to the detected driving frequency is read from the data table of FIG. Then, by driving at the maximum speed or less, the vibration wave motor 9 can be controlled at a frequency not lower than the resonance frequency.

In this embodiment, since the integrated value of the number of driving times is detected, it is not necessary to use a timer, and the first
The control can be performed more easily than the control of the second embodiment.

(Fourth Embodiment) FIG. 10 is a flow chart showing the operation of the control device according to the fourth embodiment of the present invention.
A case will be described in which time-related information is obtained by detecting the driving distance of the vibration wave motor.

In the figure, the difference from the second embodiment is that
Since steps 8 and 16 are eliminated and step 9 is only step 31, only different points will be described here.

[Step 31] In this step, u
Maximum drivable speed data is read from the memory circuit 14 based on the count value of the p / down counter 13.

In this embodiment, the information regarding the passage of time is obtained not by the driving time or the number of times of driving of the vibration wave motor but by the integrated value of the driving distance, that is, the rotation distance, and the maximum drivable speed data corresponding to the driving distance is used as a table. have.

As shown in FIG. 11, the characteristic of the vibration wave motor with respect to the frequency changes with the driving distance of the vibration wave motor. As can be seen from the figure, as the driving distance increases, the resonance frequency increases and the maximum speed decreases. In the memory circuit 14, as shown in FIG. 12, a value (Vm7,
Vm8, Vm9) are stored as a data table. The reason why a slightly lower value is stored instead of the maximum speed is the same as in the first, second and third embodiments.

In step 31, the drive distance of the vibration wave motor is detected by reading the count value of the up / down counter 13, and the maximum drivable speed corresponding to the detected drive distance is read. By driving at a speed equal to or lower than that speed, the vibration wave motor can be controlled at a frequency not lower than the resonance frequency.

Since the integrated value of the driving distance is detected in this embodiment, it is not necessary to use a timer or count the number of driving times, and the control is simpler than in the first, second and third embodiments. Can be done.

(Correspondence between Invention and Embodiment) In the above embodiment, the microcomputer 1, the D / A converter 2 and the VCO are provided.
3 corresponds to the signal control means of the present invention, the microcomputer 1 (see step 8, step 41, etc.) corresponds to the elapsed time detection means of the present invention, the pulse plate 10, the photo interrupter 1
1, the detection circuit 12, the up / down counter 13 and the microcomputer 1 correspond to the speed detection means of the present invention, and the memory circuit 14 corresponds to the storage means of the present invention.

The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention. However, the present invention is not limited to the configurations of these embodiments, and a configuration capable of achieving the functions shown in the claims is provided. Anything will do as long as it is available.

[0083]

As described above, in the first invention of the present application, the target drive speed and the actual drive speed which are set according to the aging state of the vibration wave drive device are compared, and when both are different, the vibration is generated. The frequency of the frequency signal applied to the wave drive device is controlled. Therefore, according to the present invention, when the actual driving speed becomes faster than the target driving speed, the frequency of the frequency signal is increased to decrease the speed, or the frequency of the frequency signal is prohibited from being decreased to drive the vibration wave. It is possible to prevent further increase in the speed of the device. Therefore,
Even if the resonance frequency changes with time, it is possible to drive the vibration wave driving device at a frequency in a region higher than the resonance frequency.

In addition, in the second aspect of the present invention, the target drive speed for each aged state is stored in advance, and the target drive speed is selected by the integrated value of the drive time, the number of times, etc., which is an index indicating the aged state. Therefore, according to the present invention, it is not necessary to perform a drive for searching the resonance frequency before the actual drive, so that the main drive can be started quickly, the power consumption can be reduced, and the resonance frequency can be detected. It is possible to simplify the configuration and control process by eliminating the need to provide monitor electrodes.

In each of the above inventions, if the target drive speed is set to a speed higher than the resonance frequency,
Even if the actual drive speed increases too much, stable drive control can be performed with some margin.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a control device for a vibration wave motor that is a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an arrangement state of electrostrictive elements arranged on a back surface of a stator 9b in FIG.

FIG. 3 is a flowchart showing the operation of the control device according to the first embodiment of the present invention.

FIG. 4 is a graph showing that the characteristics of the rotational frequency of the vibration wave motor with respect to frequency vary with drive time.

FIG. 5 is a table showing a table of maximum drivable speed data according to driving time.

FIG. 6 is a flowchart showing the operation of the control device according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing an operation of the control device of the third exemplary embodiment of the present invention.

FIG. 8 is a graph showing that the characteristics of the vibration wave motor with respect to frequency are varied depending on the number of times of driving.

FIG. 9 is a table showing a table of maximum drivable speed data according to the number of times of driving.

FIG. 10 is a flowchart showing an operation of the control device of the fourth exemplary embodiment of the present invention.

FIG. 11 is a graph illustrating that the frequency characteristic of the rotational frequency of the vibration wave motor varies depending on the driving distance.

FIG. 12 is a table showing a table of maximum drivable speed data according to a driving distance.

[Explanation of symbols]

1 microcomputer 2 D / A converter 3 VCO 4 frequency divider / phase shifter 5,6 power amplifier 7,8 coil 9 vibration wave motor 9a rotor 9b stator 10 pulse plate 11 photo interrupter 12 detection circuit 13 up / down counter 14 memory Circuit A ₁ , B ₁ Electrostrictive element group A, B Frequency voltage

Claims (9)

[Claims] 1. A control device of a vibration wave driving device for applying a frequency signal to an electro-mechanical energy conversion element to excite a vibration in a vibration body to drive the vibration body and a moving body relative to each other. A time detecting means for detecting a time-dependent state of the device, a target speed setting means for setting a target drive speed in accordance with the time-dependent state detected by the time detecting means, and a speed for detecting an actual drive speed of the vibration wave driving device A detection means, and a signal control means for controlling the frequency signal when the target drive speed set by the target speed setting means and the actual drive speed detected by the speed detection means are different from each other. Control device for vibration wave drive device. 2. The signal control means increases the frequency of the frequency signal in a region equal to or higher than a resonance frequency when the actual drive speed is faster than the target drive speed. Control device for vibration wave drive. 3. The signal control means prohibits lowering the frequency of the frequency signal in a region equal to or higher than a resonance frequency when the actual drive speed is equal to or higher than the target drive speed. Item 3. A control device for a vibration wave driving device according to item 1 or 2. 4. The time-lapse detecting means detects an integrated drive time of the vibration wave drive device.
4. The control device for the vibration wave driving device according to any one of 1 to 3. 5. The time-lapse detecting means detects the cumulative number of driving times of the vibration wave driving device.
4. The control device for the vibration wave driving device according to any one of 1 to 3. 6. The time-lapse detecting unit detects an integrated drive distance of the vibration wave drive device.
4. The control device for the vibration wave driving device according to any one of 1 to 3. 7. The target speed setting means has a storage means for storing a plurality of target drive speeds corresponding to respective time-dependent states, and a target corresponding to the time-dependent state detected by the time-dependent detecting means from the storage means. The control device for the vibration wave driving device according to claim 1, wherein a driving speed is selected. 8. The vibration wave drive device according to claim 1, wherein the target drive speed is set to a speed at a frequency higher than a resonance frequency in each aging state. Control device. 9. A device using the control device according to claim 1.