JP2000188889A - Device for driving vibrating actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a device for processing data from sensors incorporated in an encoder and to achieve it at a low cost. SOLUTION: Sensors 15a, 15b facing scales are used in a rotary encoder. The pulse edges to be outputted from these sensors 15a, 15b are detected by edge-detecting circuits 24a, 24b and the clock counts to be generated between the edges are each counted by counters 25a, 25b. The counted values are held by registers 26a, 26b and the values held by the registers 26a, 26b are added by an adder 27. Based on the values obtained by the adder 27, a microcomputer 20 determines the drive frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-type actuator driving device, and more particularly to a driving device for driving a vibration-type actuator mounted on a copying machine by a direct drive method.

[0002] In particular, a vibration type actuator is applied to a photosensitive drum or a transfer belt drive unit which requires high-precision rotation performance in a copying machine.

[0003]

2. Description of the Related Art Conventionally, in a device using a DC motor, a pulse motor, an ultrasonic motor or the like as a driving source, a rotary encoder is mounted on a motor shaft to reduce unevenness in the rotational speed of the motor, and output from the rotary encoder is reduced. A device configured to control the speed of a motor based on a signal to be transmitted has been put to practical use.

On the other hand, recent advances in control technology and low cost control circuits have enabled low-cost, high-precision speed control. There was a problem with the control performed based on the output signal. That is, the rotary encoder has a problem that the center between the center of the disk-shaped scale and the center of the rotating shaft of the motor, that is, the eccentricity and the pitch unevenness of the scale, cause speed unevenness.

In order to solve this problem, Japanese Patent Laid-Open Publication No.
In the device disclosed in Japanese Patent Application Laid-Open No. 0844, sensors are arranged at two positions symmetrical with respect to the center axis of a disk-shaped scale which is a component of an encoder, and information A and B obtained from the two sensors are provided. The effect of the eccentricity has been eliminated by performing the calculation of (A + B) / 2 by the calculation means of the control device and performing speed control using the obtained calculation result.

[0006]

However, Japanese Patent Application Laid-Open No. 7-140844 does not specifically disclose a method for detecting information from two sensors or the configuration of an arithmetic means. It was difficult to implement the means. In addition, there is a demand for realizing such a detection method and a calculation means at low cost, and it is also required to meet the demand.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an apparatus for processing information from a plurality of sensors provided in an encoder. The purpose is to provide.

[0008]

According to the first aspect of the present invention, there is provided a driving apparatus for driving a vibration-type actuator mounted on a copying machine by a direct drive system. A vibration-type actuator including an electro-mechanical energy conversion element, or a rotary scale that rotates integrally with a driven body that is rotationally driven by the vibration-type actuator, and is disposed at a position opposing an outer peripheral portion of the rotary scale,
A plurality of detecting means for respectively outputting a signal corresponding to a rotation state of the rotary scale; a pulse signal converting means for converting a signal output from each of the plurality of detecting means into a pulse signal; and the pulse signal converting means Time from rising edge to next rising edge, time from falling edge to next falling edge, time from rising edge to next falling edge, falling edge to next At least one of the times to the rising edge
A counter that measures each by the number of clock generations, a register that holds each count value of the counter at the end of the measurement of the time of each pulse signal,
An adder for adding a count value corresponding to the plurality of detection means respectively held in the register, and a control means for determining a frequency of a drive voltage supplied to the vibration-type actuator based on an output value from the adder; It is characterized by having.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 2 is a diagram showing a configuration of a color copying machine equipped with a vibration type actuator driving device according to a first embodiment of the present invention.

In FIG. 2, reference numeral 1 denotes a reader unit for reading a document. Reference numerals 2a, 2b, 2c, and 2d denote image forming units, each of which includes an LED array 3a, 3b, 3c, 3d, a charger, photosensitive drums 4a, 4b, 4c, 4d, and the like. Drums 4a, 4
b, 4c, and 4d. The image forming section 2a is developing for yellow, the image forming section 2b is developing for magenta, the image forming section 2c is developing for cyan, and the image forming section 2d is developing for black. By combining the four colors, full-color copying can be performed. Reference numeral 5 denotes a transfer belt, which is a belt for conveying recording paper. The recording paper is conveyed on the transfer belt 5, and the toner of each color is transferred while passing through the image forming units 2a, 2b, 2c, and 2d. A fixing unit 6 fixes the toner formed on the recording paper by a heated fixing roller.

In the color copying machine constructed as described above, the unevenness of the rotation speed of the photosensitive drums 3a, 3b, 3c, 3d in the image forming units 2a, 2b, 2c, 2d greatly affects the print quality. . Therefore, in the present embodiment, an ultrasonic motor is used to drive the photosensitive drums 3a, 3b, 3c, and 3d, and the photosensitive drums are driven by a direct drive. The ultrasonic motor is one of the vibration type actuators and generates a high torque at the time of low-speed driving, so that direct drive can be easily performed and high-precision drive control can be realized. Note that an ultrasonic motor may also be used to drive the transfer belt 5.

FIG. 3 is a sectional view showing the structure of the ultrasonic motor. Hereinafter, the ultrasonic motor will be described with reference to FIG.

Reference numeral 7 denotes an elastic body, on which a piezoelectric element 8 is fixed. The piezoelectric element 8 is subjected to polarization processing so that the polarity is alternately reversed in the circumferential direction. The elastic body 7 and the piezoelectric element 8 constitute a stator. When an AC voltage having a frequency near the resonance frequency of the stator is applied to the piezoelectric element 8, a relatively large vibration is generated in the stator. The ultrasonic motor used in this embodiment is called a traveling wave type, and a traveling wave is generated on the stator.

In the elastic member 7, a rotor 9 is pressed by a spring 10 on a surface opposite to a surface on which the piezoelectric element 8 is fixed. The rotor 9 receives a force in the rotation direction by a traveling wave generated on the stator. Rotational force received by the rotor 9 is transmitted to the shaft 11 via a spring 10 or the like,
The shaft 11 will rotate. The shaft 11 is rotatably supported by bearings 12a and 12b.

A scale 14 is attached to the shaft 11. As shown in FIG. 4, slits for transmitting light are formed radially at equal intervals on the scale 14. FIG. 4 is a view of the scale 14 as viewed from the axial direction of the shaft 11.

Reference numeral 15a denotes a sensor, which is constituted by a photo interrupter. The photointerrupter includes an LED as a light source and a light receiving element. An index scale having the same pitch as the slit of the scale 14 is attached to the light receiving element. The light of the LED passes through the scale 14 and reaches the light receiving element. Scale 14
When the light is rotating, the light from the LED may or may not reach the light receiving element depending on the position of the scale 14. The electric signal output from the light receiving element is converted into a pulse signal by the comparator. 15b is a sensor similar to 15a. In addition, 13 is a cover and 16 is a base.

FIG. 5 is a view of the ultrasonic motor viewed from the scale 14 side. As can be seen from FIG.
The sensor 15b and the sensor 15b are arranged at point-symmetric positions about the axis of the shaft 11.

FIG. 6 is a diagram showing the relationship between the frequency of the AC voltage applied to the piezoelectric element of the ultrasonic motor and the rotational speed of the ultrasonic motor. As shown in FIG. 6, when the frequency (drive frequency) of the AC voltage applied to the ultrasonic motor is the same as the resonance frequency fr of the stator, the ultrasonic motor rotates at the maximum speed. Further, the speed gradually decreases as the driving frequency becomes higher than the resonance frequency fr.
When the driving frequency becomes lower than the resonance frequency fr, the rotation speed sharply decreases. In the present embodiment, the rotational speed of the ultrasonic motor is controlled by adjusting the frequency in a frequency region higher than the resonance frequency fr using this characteristic.

FIG. 1 is a block diagram showing a driving device of a vibration type actuator (ultrasonic motor) according to a first embodiment of the present invention.

In FIG. 1, reference numeral 20 denotes a microcomputer, which detects a driving state of the ultrasonic motor, determines a driving frequency of the ultrasonic motor 23 based on the detected driving state, and sets a frequency command as a frequency command. Output. The detailed processing operation of the microcomputer 20 will be described later.

Reference numeral 21 denotes a waveform forming circuit constituted by a digital circuit or the like, which receives a frequency command output from the microcomputer 20, generates four-phase pulse signals A1, A2, B1, and B2 and outputs the pulse signals to the boosting circuit 22. I do.

FIG. 7 is a diagram showing four-phase pulse signals A1, A2, B1, and B2 output from the waveform forming circuit 21.

In FIG. 7, T is a pulse period,
This corresponds to the reciprocal of the frequency command f output from the microcomputer 20. The signal phases of all four phases output from the waveform forming circuit 21 are T.

W is a pulse width, which is a value set in consideration of the electro-mechanical energy conversion efficiency when driving the ultrasonic motor 23. Here, if the pulse width W is too large, the components of the booster circuit 22 will be damaged. On the other hand, if the pulse width W is too small, a sufficient output of the ultrasonic motor 23 cannot be obtained.

Ultrasonic motor 2 used in this embodiment
3 is driven by a two-phase AC signal having a phase difference of 90 ° or −90 °. These two phases will be referred to as A phase and B phase. Among the four-phase pulse signals shown in FIG. 7, the pulse signal A1 and the pulse signal A2 are used to generate an A-phase AC signal, and the pulse signal B1 and the pulse signal B
2 is used to generate a B-phase AC signal. The pulse signal A1 and the pulse signal A2 have a phase difference of 180 °. The pulse signal B1 and the pulse signal B2 are also 180 °
Has the following phase difference. In addition, the pulse signal B1 has a phase difference delayed by 90 ° or a phase difference advanced by 90 ° with respect to the pulse signal A1. The direction of rotation of the ultrasonic motor 33 is determined depending on whether the phase difference is delayed or advanced.
FIG. 7 shows a case where the B phase has a phase difference of 90 ° delayed from the A phase.

Returning to FIG. 1, the pulse signals A1, A2, B1, and B2 output from the waveform forming circuit 21 are boosted by the boosting circuit 22 to a voltage at which the ultrasonic motor 23 can be driven.

FIG. 8 is a circuit diagram showing the internal configuration of the booster circuit 22.

In FIG. 8, 30a, 30b, 30c,
Reference numeral 30d denotes an N-channel FET, which performs switching so that the pulse signal input from the waveform forming circuit 21 is ON when the pulse signal is at a high level and OFF when the pulse signal is at a low level. By this switching operation, the current flowing on the primary side of the transformers 31a and 31b with center taps is controlled. One end of each of the secondary sides of the transformers 31a and 31b is connected to the ground, and the other end is connected to the ultrasonic motor 2
3, and an A-phase or B-phase drive signal is supplied to the ultrasonic motor 23.

Thus, the ultrasonic motor 23 rotates according to the frequency command output from the microcomputer 20.

The rotation state of the ultrasonic motor 23 is determined by the sensor 1
Detected by 5a, 15b. That is, the sensor 15
a and 15b output a high-frequency pulse when the rotational speed of the ultrasonic motor 23 is high, and a low-frequency pulse when the rotational speed of the ultrasonic motor 23 is low.

When the scale 14 is eccentrically attached to the shaft 11, the sensor 15
a, the period of the pulse signal output from each of the 15b,
It changes with one rotation time of the shaft 11 as a cycle. That is, since the positions on the scale 14 detected by the sensor are not equidistant from the center of the scale 14, when the distance between the position on the scale 14 detected by the sensor and the center of the scale 14 is long, the pulse signal When the period is long and the distance is short, the period of the pulse signal is short. In other words, the frequency of the pulse signal output from each of the sensors 15a and 15b has a constant value if there is no eccentricity and the ultrasonic motor 23 is rotating at a constant speed. Of one rotation time.

FIG. 9 is a diagram showing how each value of the frequency of the pulse signal output from the sensors 15a and 15b fluctuates with one rotation time of the shaft 11 as a cycle.

As can be seen, if the scale 14 is eccentric with respect to the shaft 11, if the ultrasonic motor 23 is rotating at a constant speed, the sensors 15a and 15a
The value of the frequency of each pulse signal output from b is a sine wave whose phase is shifted by 180 °. Therefore, the sensor 15
When the speed control of the ultrasonic motor 23 is performed based on the speed information obtained only from the sensor a or only the sensor 15b, the rotational speed of the ultrasonic motor 23 includes a fluctuation component due to eccentricity. Therefore, the sensor 15a and the sensor 15
The eccentricity fluctuation component is canceled by adding the two pieces of speed information obtained from b and b.

Returning to FIG. 1, the circuits 24a to 26a, the circuits 24b to 26b, and the circuit 27 are all digital circuits. All the sequential circuits are synchronous circuits of the same clock.

24a and 24b are edge detection circuits. Each of the edge detection circuits 24a and 24b
The circuit outputs a high level for one clock period when the output pulse (encoder pulse) of the sensor 15a or the sensor 15b rises, and outputs a low level otherwise. Each of the edge detection circuits 24a and 24b has a configuration as shown in FIG.

The output terminals of the edge detection circuits 24a and 24b are connected to the synchronous clear input terminals of the counters 25a and 25b, respectively. Therefore, the counters 25a, 25
5b, upon receiving the high-level signals from the edge detection circuits 24a and 24b, respectively, clears the counter value to 0 by the input of the clock immediately thereafter. Thereafter, the counters 25a and 25b respectively output the edge detection circuits 24a and 24a.
The count-up based on the clock is continued until the next high-level signal is received from 24b.

In the registers 26a and 26b, output terminals of the counters 25a and 25b are connected to data input terminals, respectively, and output terminals of the edge detection circuits 24a and 24b are connected to enable input terminals. Therefore, each data of the counters 25a and 25b (data immediately before being cleared) when the high level signals are output from the edge detection circuits 24a and 24b, respectively, is written to the registers 26a and 26b at the next clock. become.

By such an operation, the register 26a sequentially stores the data representing the cycle of the pulse signal output from the sensor 15a in the number of clocks. Similarly, data representing the cycle of the pulse signal output from the sensor 15b in the number of clocks is sequentially stored in the register 26b.

FIG. 15 is a timing chart showing the above operation. FIG. 15 is a timing chart showing signals of respective parts of the driving device shown in FIG. FIG.
, A is a clock signal, B is a signal obtained by converting the output of the sensor into a pulse signal, C is an output signal from an edge detection circuit, D is a count value of a counter, and E is data held in a register.

Both data of the two registers 26a and 26b are added by an adder 27, and the obtained information is
At 0, the microcomputer 20 performs speed control based on the received information.

FIG. 11 is a flowchart showing the procedure of the control processing performed by the microcomputer 20.

The microcomputer 20 performs a calculation by a timer interrupt generated at equal time intervals to determine a drive frequency command for the ultrasonic motor 23. As a control method in this embodiment, PI control of speed, that is, proportional integral control is performed.

In FIG. 11, a timer interrupt has occurred in step 1. In step 2, the microcomputer 20
Captures the output data (Tc) from the adder 27. The data obtained from the adder 27 is two sensors 1
Since it is the sum of the period information of 51 and 15b, step 3
Then, the calculation of Vc = 2 / Tc is performed, whereby the speed information Vc is obtained. The speed information Vc is, to be precise, the number of encoder pulse cycles per clock cycle time in which the periodic fluctuation due to the eccentricity has been canceled.

In step 4, the speed information Vc and the target speed V
The difference between r, that is, the speed deviation Δv is calculated. Here, the target speed Vr is a speed determined based on the clock used in the present embodiment, and is not a unit value such as 1 / sec or rpm. Specifically, it is a value represented by the number of cycles per clock cycle time.

In step 5, the integration operation is performed by adding the newly obtained velocity deviation Δv to the value of the variable vi. The variable vi immediately after the activation of the ultrasonic motor 23 is set to zero.

In step 6, a calculation is performed based on the following equation to determine the drive frequency f of the ultrasonic motor 23.

F = fo + Kp.times..DELTA.v + Ki.times.vi Here, fo is an initial frequency, which is a predetermined drive frequency initially set immediately after the ultrasonic motor 23 is started.
Kp and Ki are a proportional gain and an integral gain, respectively, and are control gains of a proportional term and an integral term of PI control, which is a control method in the present embodiment.

In step 7, by outputting the frequency determined in step 6 to the waveform forming circuit 21, the drive frequency of the ultrasonic motor 23 is updated to the newly determined value. After that, the interrupt operation is completed in step 8,
It will wait for the next interrupt to occur.

The above processing is performed each time a timer interrupt occurs, whereby the rotational speed of the ultrasonic motor 23 is maintained at a speed corresponding to the target speed Vr.

In this embodiment, the microcomputer 2
Although the speed information is obtained by calculating the reciprocal of the cycle information of the sensor obtained from the adder 27 using 0, the present invention is not limited to this.
The deviation may be calculated without calculating the reciprocal, and the control may be performed based on the deviation.

Further, the control method is not limited to the PI control as in the above-described embodiment, and the control may be performed by PID control, PD control, fuzzy control, or modern control theory. Further, in the present embodiment, the microcomputer 2
However, the present invention is not limited thereto, and may be realized by hardware control using a digital circuit or an analog circuit.

(Second Embodiment) Next, a second embodiment will be described.

The configuration of the second embodiment is basically the same as the configuration of the first embodiment. Therefore, in the description of the second embodiment, the configuration of the first embodiment will be used, and a different configuration will be described. Only the part will be described.

FIG. 12 is a diagram showing a configuration of an ultrasonic motor according to a second embodiment of the present invention.

In the second embodiment, the scale 14 and the sensors 15a, 1 of the ultrasonic motor in the first embodiment are used.
A scale and a sensor having a configuration different from that of 5b are provided.

In FIG. 12, reference numeral 32 denotes a magnescale (magnetic disk) in which a plurality of magnetic poles are magnetized at equal pitches in the circumferential direction. 33a and 33b are magnetoresistive elements (MR elements) for detecting the magnetization pattern of the magnescale 33.

When the magnescale 32 rotates, the resistance values of the magnetoresistive elements 33a and 33b change according to the rotation. By detecting this resistance value by a bridge circuit (not shown), the same operation as the control device of the first embodiment shown in FIG. 1 is performed.

(Third Embodiment) Next, a third embodiment will be described.

The configuration of the third embodiment is basically the same as the configuration of the first embodiment. Therefore, in the description of the third embodiment, the configuration of the first embodiment will be used, and a different configuration will be described. Only the part will be described.

FIG. 13 is a view showing a configuration of an ultrasonic motor according to a third embodiment of the present invention.

In the third embodiment, the number of sensors is increased from two to four by adding sensors 15c and 15d to the sensors 15a and 15b in the ultrasonic motor of the first embodiment. . Sensors 15a to 15d
Are arranged at 90 ° intervals along the circumference of the scale 14. Further, a new configuration is added to the driving device as described below.

FIG. 14 is a block diagram showing a driving device according to the third embodiment.

FIG. 14 is different from the driving device according to the first embodiment shown in FIG.
Detection circuit 24c, counter 25c, register 26c, and edge detection circuit 24d
That is, a counter 25d, a register 26d, an adder 35, and an adder 36 are added.

The edge detection circuit 24c, the counter 25c,
The register 26c, the edge detection circuit 24d, the counter 25d, the register 26d, and the adder 35 are the edge detection circuit 24a, the counter 25a, the register 26a, the edge detection circuit 24b, the counter 25b, and the register 26b.
Then, the same operation as the adder 34 is performed. The adder 36 adds the information output from the adders 34 and 35 and adds
Send to 0.

The operation of the microcomputer 20 is almost the same as that of the first embodiment, except that the operation in step 3 (FIG. 11) is Vc = 4 / Tc. Here, Tc is the total value of the output values of the registers 26a to 26d. Other operations are the same as those of the first embodiment.

In the third embodiment, by setting the number of sensors to four, it is possible to reduce not only the error due to the periodic fluctuation component due to the eccentricity of the scale but also the pitch error generated at the time of manufacturing the scale. Also, in the present embodiment, the number of sensors is four, but the number of sensors is three, such as five.
Any number may be used as long as it is equal to or more than the number.

In each of the embodiments described above, the ultrasonic motor has been described as an example. However, the present invention can be applied to a rotary motor of another system, for example, an electromagnetic motor.

[0069]

As described above in detail, according to the first to third aspects of the present invention, a plurality of sensors facing the scale are used for the rotary encoder, and the edges of the pulses output from these sensors are detected. Each is detected, the number of clocks generated between edges is counted by a counter, the count value is held by a register, the value held by the register is added by an adder, and the drive is performed based on the value obtained by the adder. Determine the frequency.

As a result, a highly accurate speed control can be performed even if the scale has pitch unevenness, and a driving device can be realized with a simple and inexpensive configuration.

According to the fourth and fifth aspects of the present invention, two or four sensors are arranged symmetrically about the rotation axis of the rotary encoder. A detection error due to the generated eccentricity can be removed, and high-accuracy speed control can be realized.

According to the sixth aspect of the present invention, since an ultrasonic motor that generates a high torque at a low speed is used as the vibration type actuator, a high precision that requires a direct drive is particularly required. Also in the apparatus, it is possible to reduce the influence of eccentricity and pitch unevenness.

According to the seventh aspect of the present invention, since the vibration type actuator is used for driving the photosensitive drum or the transfer belt of the copying machine, high-precision printing can be performed in the copying machine. Becomes

[Brief description of the drawings]

FIG. 1 is a block diagram showing a driving device for a vibration-type actuator according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a color copying machine equipped with the vibration-type actuator driving device according to the first embodiment.

FIG. 3 is a sectional view showing a configuration of an ultrasonic motor.

FIG. 4 is a view of the scale as viewed from an axial direction of a shaft.

FIG. 5 is a view of the ultrasonic motor as viewed from a scale side.

FIG. 6 is a diagram illustrating a relationship between a frequency of an AC voltage applied to a piezoelectric element of the ultrasonic motor and a rotation speed of the ultrasonic motor.

FIG. 7 is a diagram illustrating four-phase pulse signals output from a waveform forming circuit;

FIG. 8 is a circuit diagram showing an internal configuration of a booster circuit.

FIG. 9 is a diagram showing how each value of the frequency of a pulse signal output from two sensors fluctuates with one rotation time of the shaft as a cycle.

FIG. 10 is a circuit diagram showing an internal configuration of an edge detection circuit.

FIG. 11 is a flowchart illustrating a procedure of a control process performed by the microcomputer.

FIG. 12 is a diagram showing a configuration of an ultrasonic motor according to a second embodiment of the present invention.

FIG. 13 is a diagram illustrating a configuration of an ultrasonic motor according to a third embodiment of the present invention.

FIG. 14 is a block diagram illustrating a driving device according to a third embodiment.

FIG. 15 is a timing chart showing signals of respective parts of the driving device shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reader part 2a, 2b, 2c, 2d Image formation part 5 Transfer belt 7 Elastic body 8 Piezoelectric element 9 Rotor 11 Shaft 14 Scale 15a, 15b, 15c, 15d Sensor (detection means) 20 Microcomputer (control means) 21 Waveform formation circuit 22 Step-up circuit 23 Ultrasonic motor 24a, 24b, 24c, 24d Edge detection circuit 25a, 25b, 25c, 25d Counter 26a, 26b, 26c, 26d Register 27, 34, 35, 36 Adder

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akio Atsuta 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tadashi Hayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Jun Ito 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H071 CA02 CA05 DA15 DA26 DA31 DA32 EA14 5H680 AA00 BB03 BB16 BC00 BC05 CC02 CC07 DD01 DD15 DD23 DD53 DD66 DD73 DD87 DD97 EE03 EE21 EE23 FF23 FF25 FF30 FF33 FF38

Claims (7)

[Claims] 1. A driving device for driving a vibration-type actuator mounted on a copying machine by a direct drive method, comprising: a vibration-type actuator having an electromechanical energy conversion element; A rotary scale that rotates integrally with the driven body; a plurality of detection units that are respectively disposed at positions opposing an outer peripheral portion of the rotary scale and output signals according to a rotation state of the rotary scale; A pulse signal converting means for converting a signal output from each of the detecting means into a pulse signal, and a time from a rising edge to the next rising edge of each pulse signal output from the pulse signal converting means, a falling edge. Time from the first falling edge to the next A counter for measuring at least one of a time from a rising edge to the next falling edge and a time from a falling edge to the next rising edge by the number of clock generations; and completion of measuring the time of each of the pulse signals. A register for holding each count value of the counter at the time, an adder for adding the count values corresponding to the plurality of detection means respectively held in the register, and a vibration type based on an output value from the adder. Control means for determining a frequency of a drive voltage to be supplied to the actuator. 2. The rotary scale has a plurality of slits arranged in an annular shape at a predetermined pitch, and the plurality of detecting means includes a plurality of photos arranged at equal intervals along an outer periphery of the rotary scale. The vibration-type actuator driving device according to claim 1, further comprising an interrupter. 3. The rotary scale has a plurality of magnetic poles arranged in an annular shape at a predetermined pitch, and the plurality of detecting means includes a plurality of magnetic poles arranged at equal intervals along an outer periphery of the rotary scale. 2. The vibration type actuator driving device according to claim 1, further comprising a resistance effect element. 4. The apparatus according to claim 1, wherein the plurality of detecting means are two detecting means, and are disposed at point-symmetric positions with respect to a rotation axis of the rotary scale. The vibration type actuator driving device according to the above. 5. The apparatus according to claim 1, wherein the plurality of detecting means are four detecting means, and are arranged at every 90 degrees along the outer circumference of the rotary scale. Vibration type actuator drive device. 6. The vibration type actuator driving device according to claim 1, wherein said vibration type actuator is an ultrasonic motor. 7. The apparatus according to claim 1, wherein the vibration type actuator is mounted on a member for driving a photosensitive drum or a transfer belt in the copying machine by a direct drive method. A vibration type actuator driving device according to any one of the above.