JP2000078867A - Controller for oscillatory wave driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To desirably control an oscillatory wave motor by properly controlling the phase of the motor even when the phase difference for controlling phase difference is inverted after the motor is started by waveform distortion, etc., by driving the motor in the speed increasing direction even when the phase different value falls in such a phase difference region that is not able to occur during normal operation at the time of starting the motor. SOLUTION: The count values corresponding to preset phase difference θ1, θ2, and θ3 are inputted to the other inputs of three comparator and, in the first, second, and third comparators, the phase differences between the phase differences between A and S-phases are respectively compared with the phase differences θ1, θ2, and θ3. When the phase difference between the A- and S-phases is inverted, the occurrence of such control that the driving speed of an oscillatory motor is decreased though the motor is just started by ignoring the phase status when a PLE3 is in an 'H' state, and so on, by judging that it is impossible that the PLE3 becomes the 'H' state under normal control, because it exceeds a resonance point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vibration wave driving device.

[0002]

2. Description of the Related Art A vibration wave driving device excites, for example, bending vibrations having different phases from each other by a piezoelectric element as an electro-mechanical energy conversion element, and drives a traveling wave by synthesizing these bending vibrations. A vibrating body is formed on the surface, and the vibrating body has a basic structure. For example, a driving means such as a paper feeder, a moving body of a vibrating linear motor (added to a fixed rail). Pressure contact and moves along the fixed rail), and is used for a stator of a vibration wave motor or the like.

As a control method for controlling the driving of such a vibration wave driving device, for example, as shown in Japanese Patent Application Laid-Open No. Hei 6-14565, a driving signal to a piezoelectric element for driving a vibrating body, a vibration detection A drive control based on a phase difference of an output signal from a piezoelectric element for use is disclosed.

The phase control is a method of detecting a phase difference between a driving signal to a driving piezoelectric element and an output signal from a vibration detecting piezoelectric element, and performing frequency control based on information on the obtained phase difference. .

[0005] As a characteristic of the vibration wave driving device, since a region having a frequency higher than the resonance frequency is used, when the vibration wave driving device, for example, the vibration wave motor is started, the driving frequency is gradually decreased from the higher one. When the speed gradually increases after the vibration wave motor starts rotating, the phase difference gradually approaches the resonance state. When the phase is in resonance,
The rotation speed of the vibration wave motor reaches near the highest speed.

When the frequency is further reduced from the resonance state, the rotation speed rapidly decreases, and the phase also deviates from the resonance state. Therefore, in order to prevent the phase from proceeding from the resonance state to a lower frequency, when the phase is detected and approaching the resonance state, control is performed to return the frequency to a higher frequency.

The relationship between the frequency and the frequency of the vibration wave motor and the phase difference is as shown in FIG. In the phase control, for example, phases θ1 and θ2 are set, and when the detected phase difference is smaller than θ1, the speed is increased by lowering the frequency. If the detected phase difference exceeds θ2, it is determined that resonance has been approached, and control is performed so as to decrease the speed by increasing the frequency.

[0008]

However, in the above-mentioned conventional example, a driving signal to a piezoelectric element as a driving electro-mechanical energy conversion element is generated due to the characteristics of the vibration wave motor.
In a vibration wave motor that starts with a phase difference of an output signal from a piezoelectric element serving as a vibration-detecting electro-mechanical energy conversion element substantially in phase, if the detection signal is blurred due to noise or uneven rotation, etc. Electricity for driving
Because the phase difference between the drive signal to the mechanical energy conversion element and the output signal from the vibration-detection electro-mechanical energy conversion element is inverted, and it is judged that the phase has approached the resonance state, the frequency is returned to the higher one. There has been a problem that it is impossible to increase the speed from the driving speed at the time of starting.

An object of the invention according to the present application is to provide a driving signal to a driving electro-mechanical energy conversion element and a level of an output signal from the vibration detecting electro-mechanical energy conversion element due to characteristics of a vibration wave driving device. When the phase difference is started in substantially the same phase, desired speed control can be performed even if the phase difference at the time of startup is inverted due to noise, uneven rotation, or blurring of a detection signal due to waveform distortion due to rotational twist of the vibrating body. It is an object of the present invention to provide a control device of a vibration wave driving device which enables the control device.

[0010]

A configuration for realizing an object of the present invention according to the present application is to convert a signal for detecting a phase difference from a driving signal applied to a driving electro-mechanical energy conversion element of a vibration wave driving device. First comparing means for generating, and second comparing means for generating a signal for detecting a phase difference from a vibration detection signal output from the vibration-detecting electro-mechanical conversion energy conversion element of the vibration wave driving device. And a phase difference detecting means for detecting a phase difference from outputs of the first comparing means and the second comparing means, and the driving electro-mechanical device based on phase difference information from the phase difference detecting means. In a control device of a vibration wave driving device which controls a drive signal applied to an energy conversion element and starts up with a phase difference between the drive signal and a vibration detection signal being substantially the same, a first position using the phase difference information is used. Difference And a second phase difference region that can occur during startup but cannot occur during normal operation, and drive is performed in the speed increasing direction even when the phase difference is the value of the second phase difference region at startup. Things.

In the above configuration, due to the characteristics of the vibration wave motor as the vibration wave driving device, the drive signal to the driving electro-mechanical energy conversion element and the output signal from the vibration detection electro-mechanical energy conversion element In the case of a vibration wave motor that starts up with substantially the same phase difference, when the phase difference at the time of startup is inverted due to noise, uneven rotation, or blurring of a detection signal due to waveform distortion or the like due to rotational distortion of the vibrating body,
When it is determined that a phase difference exists in the second phase difference region,
This means that a state in which the vibration wave motor is driven beyond the resonance point, which is impossible in actual vibration wave motor control, is detected.In this state, it is detected that the phase difference has been inverted due to noise or the like. By ignoring the result, the vibration wave motor can be controlled normally without the problem that the speed does not increase from the speed at the time of starting.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS.
Shows a first embodiment of the present invention.

FIG. 1 is a block diagram showing a case where a vibration wave motor is used as a motor for auto-focusing a photographic lens mounted on a camera according to the present invention. In FIG. 1, a lens CPU 1 is electrically connected to a camera CPU 19 through a contact point 18, and a lens CP 1 is connected through this terminal.
U communicates with the camera CPU to stop driving of the focus vibration wave motor and the diaphragm, and to request transmission of lens data from the camera. The lens CPU 1 performs a process according to a command from the camera CPU 19.

When the lens CPU 1 receives a drive command for the focus vibration wave motor from the camera CPU 19, the D / A conversion is performed so that a predetermined frequency is obtained in order to drive the focus vibration wave motor 13 at a predetermined frequency. Vessel 2
To send predetermined data. The D / A converter 2 is a lens C
The voltage value corresponding to the digital data from PU1 is
The signal is output to a frequency converter (hereinafter, VCO) 3.

The VCO 3 sends a signal having a frequency corresponding to the input voltage value to the frequency divider / phase shifter 4. The frequency divider / phase shifter 4 outputs a frequency signal from the VCO 3 as a rectangular wave having a phase difference of two 90 degrees or 270 degrees AOUT and BOUT.

The signal DIR sent from the lens CPU 1 to the frequency divider / phase shifter 4 determines the rotation direction of the vibration wave motor, and changes the phase difference between AOUT and BOUT to 90 degrees and 270 degrees according to this signal. It is to let.

Further, the lens CPU 1 to the frequency divider / phase shifter 4
The ON / OFF signal sent to the ON / OFF switch turns the vibration wave motor 13 ON and OFF, and the frequency divider / phase shifter 4 turns on / off the output of the AOUT and BOUT signals in response to this signal.
It operates to perform FF.

The rectangular wave AO output from the frequency divider / phase shifter 4
The UT and BOUT are amplified by the power amplifiers 5 and 6 into voltages and currents that can drive the vibration wave motor 13.

AOUT amplified by the power amplifiers 5 and 6,
The BOUT signal passes through the matching coils 7 and 8 and is supplied to each drive piezoelectric element of the vibration wave motor 13 by a drive signal (A phase,
(B-phase drive signal).

When the A-phase and B-phase drive signals are supplied to the vibration wave motor 13, the vibration wave motor 13 moves in pressure contact with a stator as a vibrating body in a direction corresponding to the A-phase and B-phase. The rotor as a body rotates.

When the rotor of the vibration wave motor rotates, for example, the pulse plate 15 that rotates integrally with the rotor rotates, and a signal corresponding to the rotation is output by the photo interrupter 16 and amplified and shaped by the pulse detection circuit 17. Lens C
Sent to PU1. The lens CPU 1 counts this pulse, determines whether or not the driving amount sent from the camera CPU 19 has been reached, and controls the driving and stopping of the vibration wave motor 13.

A phase, which is one of the drive signals for driving the vibration wave motor 13, is sent to the first comparison circuit 9 for waveform shaping to be used for phase control. Further, the vibration wave motor 13 is provided with a piezoelectric element for detecting vibration, and a detection signal (hereinafter referred to as S phase) is also sent to the second comparison circuit 10 for waveform shaping so as to be used for phase control.

One input terminal of each of the first and second comparison circuits 9 and 10 is connected to a certain reference voltage, and compares this reference voltage with A-phase and S-phase signals to output a rectangular wave. The outputs shaped by the first and second comparators 9 and 10 are sent to the phase detector 12.

The phase detector 12 outputs the signal of the second comparator 10 from the output signal of the first comparator 9 and the second comparator 10, for example, from the rise of the signal of the first comparator 9. By counting the number of clocks up to the rising edge and comparing it with a counter value corresponding to a preset first, second and third phase difference, the position of the output of the first and second comparison circuits 9 and 10 is obtained. The phase difference, that is, the range of the phase difference between the A phase and the S phase is determined, and the result is sent to the lens CPU 1 as signals PLE1, PLE2, and PLE3 described later, for example.

The lens CPU 1 changes the data to the D / A converter 2 according to the detected phase difference, and controls by changing the frequency of the drive signal for driving the vibration wave motor 13. Become.

Depending on the characteristics of the vibration wave motor 13, FIG.
As shown in FIG. 1A, when the vibration wave motor is started, the amplitude of the S-phase signal may not be sufficiently obtained, and an accurate phase difference may not be detected. As a countermeasure, for example, the capacitor 14 shown in FIG.
A slight overlap with the phase is mentioned.

When the A phase is superimposed on the S phase, FIG.
Is obtained, and the phase difference is correctly detected. In this case, the A phase and the S phase at the time of startup are substantially the same.

As shown in FIG. 11C, the relationship between the A phase and the S phase of the vibration wave motor 13 is such that the S phase gradually delays from the A phase when the speed increases after the start. I do.

If the delay of the S phase exceeds a certain phase difference, the rotational speed of the vibration wave motor 13 sharply decreases. Therefore, control is performed so that the A phase and the S phase do not exceed a predetermined phase difference (θ2 in FIG. 12). I do.

The phase detector 12 is constructed, for example, as shown in FIG. In FIG. 2, data from lens CPU1 to DATA
0 to 3 are sent to the latch circuits 202, 203, and 204. This data is a phase difference θ1, θ
2, a counter value corresponding to θ3.

The counter values corresponding to .theta.1, .theta.2, and .theta.3 are determined by the encoder 201. For example, data corresponding to .theta.1 is stored in the latch circuit 202, data corresponding to .theta.2 is stored in the latch circuit 203, and data corresponding to .theta.3 is stored in the latch circuit 2.
04 respectively.

S which is a select signal of the encoder 201
EL0 and SEL1 are selected by the lens CPU1.

The preset stored phase differences θ1, θ2,
Data corresponding to θ3 are compare 212, 213, 21
4 is connected to one of the inputs for comparison.

As shown in FIG. 13, the A-phase and the S-phase are, for example, a point where the A-phase signal crosses zero.
The number of clocks until the S-phase signal crosses zero is obtained by counting. The number of clocks of the preset phases θ ₁ , θ _2, etc. (for example, Lθ ₁ ,
Lθ ₂ ). For example, at some point A,
When the phase of the S phase is obtained, the number of clocks _Lx is obtained. To find the position of this phase with respect to the preset phases θ ₁ and θ ₂ , L _x , θ ₁ and θ ₂
Compare the magnitude relation of. If Lθ ₁ <L _x <Lθ ₂ , the current phase is between θ ₁ and θ ₂ . This L _x and Lθ ₁ , L
The comparison of θ ₂ is called a compare.

On the other hand, the first comparator 9 which shaped the A-phase signal
Is input to a clock terminal of the latch circuit 205. The input terminal of the latch circuit 205 is connected to the “H” voltage, and the output (CEN) of the latch 205 becomes “H” when the AIN signal rises.
This CEN signal is connected to the enable signal of the counter 210, and counts the clock input to the clock terminal while the enable signal is 'H'. The count values of the counter 210 are compared 212, 213, and 21.
4 are connected to one of the four comparison inputs.

The other inputs of the compare units 212, 213, and 214 have preset phase differences θ1, θ2.
2. A count value corresponding to θ3 is input, and a compare 2
At 12, the current phase difference between the A phase and the S phase and the phase difference of the phase difference θ1 are compared, and a result indicating whether or not the current phase difference exceeds θ1 is output as a COUT1 signal.

Similarly, a signal indicating whether or not the current phase difference between the A phase and the S phase exceeds θ2 is output from the compare 213.
It is output as a UT2 signal.

Also, a signal indicating whether or not the current phase difference between the A phase and the S phase exceeds θ3 is output from the compare 214.
It is output as a T3 signal.

On the other hand, the second comparator 1 which shaped the S-phase signal
The SIN signal, which is an output of 0, is input to the D terminal of the latch circuit 206. Due to the latch circuit 206 and the NAND gate 207, the output (CRA1) of the NAND gate becomes 'L' for one clock only when the SIN signal rises. When the CRA1 signal becomes "L", the latch circuit 2
05 is cleared, and the CEN signal becomes 'L'.

Accordingly, since the enable terminal of the counter 210 becomes “L”, the counter 210 stops the counting operation.

The AIN signal is supplied to the latch circuit 208.
D input. This latch circuit 208 and A
By the ND gate 209, the output (LAPLE) of the AND gate becomes “H” for one clock only when the AIN signal rises.

This LAPLE signal is supplied to the latches 215 and 21.
6, 217 are connected to the clock terminals. A latch circuit 215 latches the COUT1 signal. Similarly, a latch circuit 216 latches the COUT2 signal, and a latch 217 latches the COU1 signal.
Each of the T3 signals is latched at the rise of the LAPLE signal.

Therefore, the state of the phase difference (θ1, θ2, θ) from the previous rise of the A-phase to the rise of the S-phase
3 or not) is held at the rise of the current A-phase.

The LAPLE signal is output from the latch circuit 211.
As an inverted signal (CRA2) delayed by one clock,
It is input to the reset terminal of the counter 210.

Therefore, the count result of the counter 210 is cleared immediately after the rise of the AIN signal, and after the result of the compare is latched by the latch circuits 212, 213, and 214. At this time, the clock is originally counted from the rising of the AIN signal to the rising of the SIN signal. However, actually, two clocks are not counted. However, if there is a problem in performance, another circuit configuration is required. It is also possible to take.

FIGS. 3 to 6 show the signal states of the A and S phases and the waveforms of the main part of the phase detector 12. FIG.

FIG. 3 shows a case where the phase difference between the A phase and the S phase does not exceed the phase difference set value θ1. Since the count value from the rise of the AIN signal to the rise of the SIN signal does not exceed the counter values corresponding to θ1, θ2, and θ3 set in advance, PLE1, PLE2, PLE
All of the signals of No. 3 become 'L'.

FIG. 4 shows that the phase difference between the A phase and the S phase is the phase set value θ.
This is the case between 1 and θ2. When the count value from the rise of the AIN signal to the rise of the SIN signal exceeds the count set value corresponding to the phase difference θ1, C
OUT1 becomes 'H', and the result is latched at the next rising edge of the AIN signal, and PLE1 becomes 'H' and PLE2
Is "L" and PLE3 is "L".

FIG. 5 shows that the phase difference between the A phase and the S phase is the phase set value θ.
This is the case between 2 and θ3. Therefore, when the count value from the rise of the AIN signal to the rise of the SIN signal exceeds the count set value corresponding to the phase difference θ1, COUT1 becomes “H”, and when the count value exceeds the count value corresponding to the phase difference θ2, COUT2 becomes COUT2. Becomes 'H'. The result is latched at the next rising edge of the AIN signal, and PLE1 is latched.
Is 'H', PLE2 is 'H', and PLE3 is 'L'.

FIG. 6 shows an example in which the phase difference between the A phase and the S phase is inverted at the time of starting. When the phase difference between A phase and S phase is reversed,
The phase difference will exceed θ3.

However, from the rising edge of the AIN signal, SI
When the count value until the rise of the N signal exceeds the count set value corresponding to the phase difference θ1, COUT1 becomes 'H', and when the count value exceeds the count value corresponding to the phase difference θ2, COUT becomes
When OUT2 becomes “H” and further exceeds the count set value corresponding to the phase difference θ3, COUT3 becomes “H”.

The result is latched at the next rising edge of the AIN signal, PLE1 is at "H", PLE2 is at "H",
The result that PLE3 is 'H' is obtained.

Incidentally, the phase control of the vibration wave motor using the A phase and the S phase is performed as shown in FIG. If the phase difference between the A phase and the S phase does not exceed θ1, as shown in FIG.
Control is performed so that the drive frequency of the vibration wave motor is reduced and the drive speed is increased.

If the phase difference between the A phase and the S phase is between θ1 and θ2 as shown in FIG. 7B, the driving speed is maintained by maintaining the driving frequency.

Further, as shown in FIG.
Is exceeded, the drive frequency is increased to control the drive speed to decrease. Therefore, the phase control is performed so that the phase difference between the A phase and the S phase is between θ1 and θ2. This is because there is a resonance point of the vibration wave motor at a certain position exceeding θ2, and if the frequency is reduced to this point, the rotation speed of the vibration wave motor rapidly decreases.

Here, a case where the phase difference setting θ3, which is a conventional example, is not set will be described so that the effect of the present embodiment can be clearly understood.

At the start of the vibration wave motor, if the phase difference between the A phase and the S phase is obtained as shown in FIG.
Since both LE1 and PLE2 are “L”, it is determined that the phase difference between the A phase and the S phase does not exceed θ1, and the drive speed can be controlled to be increased by lowering the drive frequency.

However, when driving the vibration wave motor, noise is generated.
If the S-phase signal is blurred due to rotation unevenness or waveform distortion due to the rotation torsion of the vibrator or the like, and if the inversion of the originally impossible A-phase and S-phase as shown in FIG. Since both PLE2 are at “H”, the lens CPU 1 determines that the phase difference between the A phase and the S phase exceeds θ2, increases the drive frequency, and controls to decrease the drive speed.

Therefore, when the vibration wave motor is started, the speed is controlled to be reduced from the low speed state, so that the vibration wave motor keeps moving slowly.

On the other hand, as in the present embodiment, a third phase difference setting other than the first and second phase differences θ1 and θ2 for sandwiching the phase is performed, for example, by setting a lower frequency than the resonance point of the vibration wave motor. When the phase difference between the A-phase and the S-phase is reversed as shown in FIG. 6, the PLE3 becomes "H", and the PLE3 becomes "H" because it is beyond the resonance point, so that the normal control state is set. Then, it is determined that the driving speed cannot be reduced because the phase state when the PLE3 is “H” is ignored.

When PLE3 is "L", it is determined that the phase difference is correctly detected. When PLE1 is "L", the driving frequency is lowered. When PLE1 is "H" and PLE2 is "L", the driving frequency is lowered. Maintains the driving frequency, and PLE2 becomes “H”
In the case of, control is performed to increase the drive frequency.

FIG. 8 is a flowchart showing the above process. FIG. 8 is described below.

# 801: Vibration wave motor drive.

# 802: It is determined whether or not PLE3 is "H". If PLE3 is 'H', the process proceeds to # 808, and if it is 'L', the process proceeds to # 803.

# 803: It is determined whether or not PLE1 is "L". If PLE1 is 'L', go to # 804; if 'H', # 8
Go to 05.

# 804: Control is performed so as to increase the rotation speed by lowering the drive frequency. # 805: It is determined whether PLE2 is 'L'. PLE2
Is 'L', PLE1 is 'H' and PLE2 is 'L'
Therefore, it is determined that the phase difference is between θ1 and θ2, and the process proceeds to # 806. If it is determined that PLE2 is not "L", it means that PLE1 and PLE2 have been determined to be "H", and the process proceeds to # 807.

# 806: Since the phase difference is determined to be between θ1 and θ2, the drive frequency is maintained as it is.

# 807: Since it is determined that the phase difference exceeds θ2, control is performed to increase the driving frequency and decrease the rotation speed.

# 808: It is determined whether the first PLE signal check after driving the vibration wave motor this time. If it is determined that this is the first PLE check of the current drive, it is determined that the speed immediately after startup is in a low speed state and the phase difference is inverted,
Proceed to # 804, if not the first check, # 80
Go to 9.

# 809: It is determined whether or not the processing of the driving frequency by the previous PLE check is the processing of lowering the frequency.

If the previous process is a process for lowering the driving frequency, the process proceeds to step # 804. If the previous processing is not the processing for lowering the driving frequency, the process proceeds to # 810.

# 810: It is determined whether or not the processing by the previous PLE check is processing to increase the driving frequency. If the process is to increase the drive frequency, the process proceeds to step # 807. If the process is not to increase the drive frequency, the previous process is determined to be the process of maintaining the drive frequency, and the process proceeds to step # 806.

# 811: It is determined whether or not a predetermined amount has been driven. If the driving by the predetermined amount has been completed, the process proceeds to # 812, and if not, the process proceeds to # 801.

# 812: The driving of the vibration wave motor is stopped.

According to the above processing, when PLE3 is "H", the drive frequency is controlled in the same manner as the previous control (however, PLE3 becomes "H" in the first phase determination after startup). In this case, lower the driving frequency.)
In this case, control is performed so that the phase difference is between θ1 and θ2.

Further, if PLE3 becomes "H" only immediately after the start-up (the phase difference between the A phase and the S phase is inverted), if PLE3 is detected as "H", a certain predetermined time is required. The configuration may be such that the drive frequency is continuously lowered without checking the PLE signal.

According to the present embodiment, the first and second phase difference setting values for controlling the phase difference between the A phase and the S phase within a predetermined value in the phase difference detection circuit, and the vibration wave motor By providing the third phase difference setting value at a position corresponding to the phase difference beyond the resonance point, when the A phase and the S phase start in substantially the same phase due to the characteristics of the vibration wave motor, the speed is maintained even if the phase difference is reversed. The vibration wave motor control can be performed normally without the problem that the motor does not rise.

According to the present embodiment, the first, second,
Since the phase difference setting value of 3 is set in a hardware manner, the lens CPU 1 can determine the phase state only by reading “H” and “L” of the PLE1, PLE2, and PLE3 signals. Processing can be performed with a reduced, low-cost, low-speed CPU, and complicated other processing can be preferentially processed.

(Second Embodiment) FIG. 9 shows a second embodiment of the present invention.
An embodiment will be described.

FIG. 9 is a circuit block diagram of a drive control device when the present invention uses a vibration wave motor as a motor for auto-focusing a photographing lens, similarly to the first embodiment.

In FIG. 9, the difference from FIG. 1 is that the phase detector 1 directly counts the count value from the rise of the A phase to the rise of the S phase for calculating the phase difference between the A phase and the S phase. Since the other configuration is the same as that of the first embodiment, the description is omitted.

The phase detector 12 according to the present embodiment is configured, for example, as shown in FIG. In FIG. 10, 1005
The logic elements 1011 to 1011 perform the same operation as the logic elements 205 to 211 in FIG.

The latch circuit 1012 stores the count value corresponding to the current phase difference between the A-phase and the S-phase by using the LACOUT signal generated at the rising of the AIN signal.
The lens CPU 1 reads the stored count value.

The lens CPU 1 calculates θ1, θ described above.
2. The phase difference data corresponding to θ3 is stored in the ROM, or the RA is stored in an external storage unit such as an EEPROM.
Read in M.

The lens CPU 1 counts the count value corresponding to the phase difference read from the phase detector, and stores the count values θ1 and θ stored in the CPU or read from the EEPROM or the like.
2. Data corresponding to θ3 is compared, and for example, processing similar to the processing shown in FIG. 8 is performed to control the driving frequency of the vibration wave motor.

According to the present embodiment, the first, second, and third preset phase difference set values are stored in the CPU or in the external storage element. In the case where the A-phase and the S-phase are started in substantially the same phase due to the above characteristics, normal vibration wave motor control can be performed without causing a problem that the speed does not increase even if the phase difference is reversed.

In this embodiment, the phase difference detection circuit for counting the phase difference between the A phase and the S phase is provided as hardware. However, this function is provided in the lens CPU 1.
It is also possible to configure so that the outputs of the first and second comparators are directly input to the lens CPU 1.

The present invention is not limited to the control device of the vibration wave motor for driving the photographing lens described above, but can be applied to a device for driving a vibration wave driving device such as a vibration wave motor.

[0089]

According to the first to sixth aspects of the present invention,
Even if the phase difference for the phase difference control is inverted after startup due to noise or uneven rotation of the vibration wave motor as a vibration wave driving device, waveform distortion due to the rotation twist of the vibration body, etc.
There is an effect that the phase control of the vibration wave motor is correctly performed, and desired vibration wave motor control is realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a logic circuit diagram of the phase detector of FIG. 1;

FIG. 3 is a diagram showing A-phase and S-phase waveforms and operation waveforms of the phase difference detector at that time according to the first embodiment of the present invention.

FIG. 4 is a diagram showing A-phase and S-phase waveforms and operation waveforms of the phase difference detector at that time according to the first embodiment of the present invention.

FIG. 5 is a diagram showing A-phase and S-phase waveforms and operation waveforms of the phase difference detector at that time according to the first embodiment of the present invention.

FIG. 6 is a diagram showing A-phase and S-phase waveforms and operation waveforms of the phase difference detector at that time according to the first embodiment of the present invention.

FIGS. 7A to 7C are diagrams showing a phase relationship between an A phase and an S phase.

FIG. 8 is a flowchart illustrating a flow of phase control according to the first embodiment;

FIG. 9 is a block diagram of a second embodiment of the present invention.

FIG. 10 is a logic circuit diagram of the phase detector of FIG. 9;

11A to 11C are waveform diagrams illustrating an example of a relationship between A-phase and S-phase signals.

FIG. 12 is a diagram illustrating frequency characteristics of the phase and the number of rotations of the vibration wave motor.

FIG. 13 illustrates a compare.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens CPU 9 1st comparator 10 2nd comparator 11 Inverter 12 Phase detector 13 Vibration wave motor

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[Procedure amendment]

[Submission date] September 11, 1998 (1998.9.1)
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

Claims (6)

[Claims] A first comparing means for generating a signal for detecting a phase difference from a driving signal applied to a driving electro-mechanical energy conversion element of the vibration wave driving device; and a vibration detection of the vibration wave driving device. Second comparing means for generating a signal for detecting a phase difference from the vibration detection signal output from the electromechanical conversion energy conversion element for use, and a signal from the outputs of the first comparing means and the second comparing means. A phase difference detector for detecting a phase difference; controlling a drive signal to be applied to the driving electro-mechanical energy conversion element based on phase difference information from the phase difference detector; And a first phase difference region using the phase difference information, which can occur at startup but cannot occur during normal operation. Second retardation region is set, the control device for a vibration wave driving apparatus characterized by phase difference is driven to a second speed increasing direction be a value of the phase difference region at startup. 2. The control device for a vibration wave driving device according to claim 1, wherein when the start is started, it is first determined whether or not a phase difference exists in said second phase difference region. 3. A method of determining whether or not to drive in the speed increasing direction based on whether or not a determination as to whether or not a phase difference exists in the second phase difference area has been performed for the first time after the current startup. The control device for a vibration wave driving device according to claim 2, wherein: 4. The method according to claim 3, wherein when the phase difference exists in the second phase difference area, but the determination is not the first time after the current activation, the previous processing is performed. 5. The first phase difference area includes a first phase difference set value for limiting speed-up control and a second phase difference set value for maintaining steady speed control. The control device for a vibration wave driving device according to claim 1, 2, 3, or 4. 6. The second phase difference region, wherein the phase difference is set on a side different from the phase difference at the time of resonance and in a direction toward the first phase difference region. The control device of the vibration wave driving device according to any one of 2, 3, 4, and 5.