JP2003037984A - Vibration wave motor drive control device, drive voltage control method, program and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong a service life of a vibration wave motor by preventing partial wear of a friction member in an elastic body (vibration body) to be connected to a moving member. SOLUTION: Booster parts 102, 103 generate a plurality of alternative signals having different phases based on a plurality of pulse signals having different phases to be generated by a pulse generating part 101 and impresses the alternative signals to piezoelectric elements in the vibration wave motor 106. While, detection parts 107, 108 detect each peak voltage of the plurality of alternative signals, a comparison unit 109 compares each detected peak voltage and the power voltage to be supplied to the booster part 103 by a variable power supply part 105 is controlled based on the compared result so that the differences of the respective peak voltages become equal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration wave motor drive control device, a drive voltage control method, a program, and a storage medium, and in particular, excites a vibrating body by applying an AC signal to an electromechanical energy conversion element. A drive control device for a vibration wave motor configured to obtain a driving force, a drive voltage control method applied to the vibration wave motor drive control device, a program for causing a computer to execute the drive voltage control method, and the program. The present invention relates to a stored storage medium.

The vibration wave motor is used as a driving means for driving a photosensitive drum, a transfer belt and the like in an image forming apparatus such as a printer, a copying machine and a facsimile machine.

[0003]

2. Description of the Related Art Conventionally, a vibration wave motor has a piezoelectric element adhered to one surface of an elastic body (vibration body) made of metal, for example, in an annular shape by an adhesive, and is used for driving the piezoelectric element. Two standing waves are excited on the elastic body by applying alternating voltages having different phases to the piezoelectric element groups, and by combining these standing waves, a progressive vibration wave that is a bending vibration is generated by the elastic body. Formed on. On the other hand, on the other side of the elastic body,
For example, a ring-shaped member is pressed by a pressing means such as a spring, and the member or the elastic body is moved by frictional driving by a progressive vibration wave formed on the elastic body.
In addition, the drive circuit that drives the piezoelectric element includes a drive signal generation unit that generates an AC wave and a rotation speed of the vibration wave motor based on the rotation speed of the vibration wave motor detected by the encoder attached to the vibration wave motor. And a control unit for performing feedback control of the.

This vibration wave motor has good rotation accuracy and resistance to transient load fluctuations, and can reduce color misregistration, pitch unevenness, and paper feed shock. It is being used for driving a photosensitive drum and a transfer belt of a forming apparatus.

A vibration wave motor is disclosed in Japanese Patent Laid-Open No. 58-14682.
As proposed in Japanese Patent Publication, a motor is generally designed to excite a plurality of vibrations in an oscillating body by an AC voltage having a frequency exceeding the audible range, and to obtain a driving force by combining them. Regarding driving, JP-A-63-1379, JP-A-60-176470, and JP-A-59-
As described in detail in Japanese Patent No. 204477, etc.,
It achieves stable rotation at a constant speed.

[0006]

In the above conventional vibration wave motor, two standing waves are excited on the elastic body by applying alternating voltages having different phases to the driving piezoelectric element groups. The progressive vibration wave, which is a bending vibration, is formed by synthesizing the standing wave of, and the member joined to the other surface side of the elastic body or the elastic body is moved, and thereby the rotation is performed. If the peak values of the alternating voltage having different phases do not match, the progressive vibration wave becomes uneven.

Due to the unevenness of the traveling wave, there is a problem that the friction material on the other surface side of the elastic body joined to the member is unevenly worn, and as a result, the life of the vibration wave motor is shortened.

The present invention has been made in view of the above problems, and an elastic body (vibrating body) joined to a moving member.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration wave motor drive control device, a drive voltage control method, a program, and a storage medium that prevent uneven wear of the friction material in the above and extend the life of the vibration wave motor.

[0009]

In order to achieve the above object, according to the invention of claim 1, an AC signal is applied to the electromechanical energy conversion element to excite the vibrating body to obtain a driving force. In the drive control device of the vibration wave motor thus configured, a plurality of AC signals having different phases are generated based on the pulse generating means for generating a plurality of pulse signals having different phases and the plurality of pulse signals generated by the pulse generating means. AC signal generating means for generating and applying to the electro-mechanical energy conversion element, detecting means for detecting each peak voltage of the plurality of AC signals, and each peak voltage detected by the detecting means are equal. In addition, there is provided a vibration wave motor drive control device comprising: a control unit that controls the AC signal generation unit.

According to the second aspect of the present invention, in the drive control apparatus for the vibration wave motor, which applies the AC signal to the electromechanical energy conversion element to excite the vibrating body to obtain the driving force, A pulse generating means for generating four different pulse signals and a first AC signal based on the first and second pulse signals generated by the pulse generating means are applied to the electric-mechanical energy conversion element. A second alternating current signal generating means, and a second alternating current signal for generating a second alternating current signal based on the third and fourth pulse signals generated by the pulse generating means and applying the second alternating current signal to the electric-mechanical energy conversion element. The signal generating means, the detecting means for detecting the respective peak voltages of the first and second alternating current signals, and the difference between the respective peak voltages detected by the detecting means are zero. 1 and the vibration wave motor drive control apparatus characterized by a control means for controlling at least one operation of the second AC signal generating means.

According to the invention of claim 8, a plurality of pulse signals having different phases are generated based on the pulse generating means for generating a plurality of pulse signals having different phases, and the plurality of pulse signals generated by the pulse generating means. Generates an AC signal to generate electricity
In a drive voltage control method applied to a vibration wave motor drive control device including an AC signal generating means for applying to a mechanical energy conversion element, a detection step of detecting each peak voltage of the plurality of AC signals, and the detection So that each peak voltage detected in the step is equal,
And a control step of controlling the AC signal generating means.

According to the invention described in claim 9, pulse generating means for generating four pulse signals having different phases, and the first alternating current based on the first and second pulse signals generated by the pulse generating means. A first alternating current signal generating means for generating a signal and applying it to the electro-mechanical energy conversion element, and a second alternating current signal based on the third and fourth pulse signals generated by the pulse generating means, A drive voltage control method applied to a vibration wave motor drive control device comprising: a second AC signal generating means for applying to the electro-mechanical energy conversion element, wherein each peak voltage of the first and second AC signals. Of at least one of the first and second AC signal generating means so that the difference between the respective peak voltages detected in the detecting step and the respective peak voltages detected in the detecting step becomes zero. Driving voltage control method characterized by a control step of controlling is provided.

According to the twelfth aspect of the present invention, a plurality of pulse signals having different phases are generated based on the pulse generating means for generating a plurality of pulse signals having different phases and the plurality of pulse signals generated by the pulse generating means. Generates an AC signal to generate electricity
In a program for causing a computer to execute a drive voltage control method applied to an oscillatory wave motor drive control device including an AC signal generating unit for applying to a mechanical energy conversion element, the drive voltage control method includes: A program comprising a detection step of detecting each peak voltage of an AC signal and a control step of controlling the AC signal generating means so that the peak voltages detected in the detection step become equal to each other. Provided.

According to the thirteenth aspect of the present invention, the pulse generating means for generating four pulse signals having different phases and the first alternating current based on the first and second pulse signals generated by the pulse generating means. A first alternating current signal generating means for generating a signal and applying it to the electro-mechanical energy conversion element, and a second alternating current signal based on the third and fourth pulse signals generated by the pulse generating means, A program for causing a computer to execute a drive voltage control method applied to an oscillatory wave motor drive control device, comprising: a second AC signal generating means for applying to the electro-mechanical energy conversion element; The method reduces the difference between the peak voltage detected in each of the peak voltages of the first and second AC signals and the peak voltage detected in the detection step to zero. As such, program characterized by a control step for controlling at least one operation of said first and second AC signal generating means.

Further, according to the invention of claim 14,
Pulse generating means for generating a plurality of pulse signals having different phases, and a plurality of AC signals having different phases are generated based on the plurality of pulse signals generated by the pulse generating means and applied to the electro-mechanical energy conversion element. In a computer-readable storage medium that stores a drive voltage control method applied to a vibration wave motor drive control device having an AC signal generating means as a program, the drive voltage control method stores the plurality of AC signals. A storage medium is provided which has a detection step of detecting each peak voltage and a control step of controlling the AC signal generating means so that the peak voltages detected in the detection step become equal. It

According to the fifteenth aspect of the present invention, the pulse generating means for generating four pulse signals having different phases and the first alternating current based on the first and second pulse signals generated by the pulse generating means. A first alternating current signal generating means for generating a signal and applying it to the electro-mechanical energy conversion element, and a second alternating current signal based on the third and fourth pulse signals generated by the pulse generating means, A computer-readable storage medium that stores, as a program, a drive voltage control method applied to an oscillatory wave motor drive control device that includes a second AC signal generation unit that applies the electro-mechanical energy conversion element, The drive voltage control method detects a peak voltage of each of the first and second AC signals, and a detection step detected in the detection step. So that the difference of over click voltage is zero,
And a control step for controlling the operation of at least one of the first and second AC signal generating means.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 5 is a sectional view showing an overall schematic structure of a color image forming apparatus having a vibration wave motor mounted therein.

First, the structure of the color reader section will be described.

401 is a CCD (charge coupled device), 411
Is a substrate on which a CCD 401 is mounted, 412 is a printer processing unit, 400 is a platen glass (platen), 402 is a document feeder (in addition to the document feeder 402, a mirror surface plate or a white plate is mounted). 40)
Reference numerals 3 and 404 denote light sources composed of halogen lamps or fluorescent lamps for illuminating the original, and 405 and 406 denote light sources 403 and 4
Reflector for converging 04 light on the original, 407-40
Reference numeral 9 is a mirror, 410 is a lens for collecting reflected light or projection light from the original on the CCD 401, and 414 is a light source 40.
3, 404, a carriage for housing the reflectors 405, 406, and the mirror 407; 415, a carriage for housing the mirrors 408, 409; Is. The carriage 414 is at the speed V and the carriage 415 is at the speed V / 2, and the CCD 40
The entire surface of the original is scanned (sub-scanned) by mechanically moving in the direction perpendicular to the first electrical scanning (main-scanning) direction.

Next, the structure of the printer section will be described.

Reference numeral 417 is a magenta (M) image forming unit, 41
8 is a cyan (C) image forming unit, and 419 is yellow (Y)
The image forming unit 420 is a black (K) image forming unit, and since the respective configurations are the same, the M image forming unit 417 will be described in detail, and the description of the other image forming units will be omitted.

In the M image forming section 417, a photosensitive drum 442 forms a latent image on its surface by the light from the LED recording head 453. A primary charger 421 charges the surface of the photosensitive drum 442 to a predetermined potential to prepare for latent image formation. A developing device 422 develops the latent image on the photosensitive drum 442 to form a toner image. The developing unit 422 includes a sleeve 460 for applying a developing bias and developing.

A transfer charger 423 discharges from the back surface of the transfer material transport belt 433 to transfer the toner image on the photosensitive drum 442 to a recording paper or the like on the transfer material transport belt 433. In this embodiment, since the transfer efficiency is high, the cleaner portion is not arranged, but the cleaner portion may be attached.

Next, the procedure for transferring a toner image onto a transfer material such as recording paper will be described.

Transfer materials such as recording papers stored in the cassettes 440 and 441 are supplied one by one by the pickup rollers 439 and 438 to the transfer material conveying belt 433 by the paper feed rollers 436 and 437. The supplied recording paper is charged by the adsorption charger 446. Reference numerals 448a to 448d denote transfer material transport belt rollers, of which the transfer material transport belt roller 448a drives the transfer material transport belt 433 and charges the recording paper or the like by forming a pair with the adsorption charger 446 to charge the transfer material. Recording paper or the like is adsorbed to the conveyor belt 433.
Note that the transfer material transport belt rollers 448b to 448d may also operate as drive rollers for driving the transfer material transport belt 433.

A paper edge sensor 447 detects the edge of recording paper or the like on the transfer material conveying belt 433. The detection signal of the paper leading edge sensor 447 is sent from the printer unit to the color reader unit, and is used as a sub-scanning synchronization signal when sending a video signal from the color reader unit to the printer unit.

Thereafter, the recording paper or the like is transferred onto the transfer material conveying belt 4
The toner images are formed on the surface of the image forming units 417 to 420 in the order of MCYK. The transfer material such as recording paper that has passed through the K image forming section 420 is separated from the transfer material conveying belt 433 after being discharged by the discharging charger 449 in order to facilitate separation from the transfer material conveying belt 433. 450 is a peeling charger,
This prevents image disturbance due to peeling discharge when the recording paper or the like is separated from the transfer material transport belt 433. The separated recording paper or the like is charged by the pre-fixing charger 451 in order to supplement the toner suction force and prevent image distortion, and then the toner image is thermally fixed by the fixing device 434, and the discharge tray 435.
Is ejected.

In this embodiment, a vibration wave motor is used to rotate the photosensitive drums 442 to 445, and a vibration wave motor is used to rotate the transfer material conveying belt roller 448a. As described above, the vibration wave motor generates a vibration wave on the surface of the elastic body by applying an AC signal to an electro-mechanical energy conversion element such as a piezoelectric element fixed to the elastic body (vibration body). The motor drives the moving body by bringing the moving body (rotor) into contact with the elastic body. Here, a case where a vibration wave motor is connected to the photosensitive drums 442 to 445 will be described as an example.

FIG. 6 is a diagram showing a connection state between the photosensitive drum and the vibration wave motor.

In FIG. 6, 502 is a photosensitive drum and 501 is a vibration wave motor. Vibration wave motor 501
A rotary encoder 500 is connected to the rotary encoder 500, and the rotary encoder 500 generates and outputs a pulse signal at a predetermined rotation position of the output shaft of the vibration wave motor 501.

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

The target value command section 120 sends a speed command to the vibration wave motor drive control device 100. The command speed (target speed) of the vibration wave motor 106 includes standard speed v [rpm] and 4v, 2v, 1 / 2v, 1 / 4v. Here, for example, the speed v is input as the speed command from the target value command unit 120 to the frequency setting unit 112 and the speed difference detection unit 111.

The frequency setting unit 112 is used for the vibration wave motor 10
At the start of driving of No. 6, a start signal having a predetermined frequency is sent to the pulse generator 101, and the pulse generator 101 generates four-phase pulse signals A1, A2, B1, B2 based on the start signal.

FIG. 2 shows four-phase pulse signals A1, A2, B.
2 is a timing chart showing B1 and B2.

The pulse generator 101 includes a frequency setting section 11
Based on the start signal sent from 2, the pulse signal A has a cycle four times as long as that of the start signal and has a predetermined pulse width.
1, A2, B1, B2 are generated. Then, a phase difference of 180 ° is provided between the pulse signal A1 and the pulse signal A2 and between the pulse signal B1 and the pulse signal B2, respectively, and further, the pulse signal A1 and the pulse signal B1 and the pulse signal A2 and the pulse signal A2 are provided. A phase difference of 90 ° is provided for each of B2 and B2.

Of the four-phase pulse signals A1, A2, B1, B2 output from the pulse generator 101, the pulse signal A
1, 1 and A2 are input to the booster 102, and pulse signals B1 and B2 are input to the booster 103.

FIG. 3 is a circuit diagram showing the internal structure of the boosting units 102 and 103.

The booster 102 generates an A-phase AC wave for driving the vibration wave motor 106 based on the pulse signals A1 and A2 sent from the pulse generator 101, and the booster 103 generates the pulse. Based on the pulse signals B1 and B2 sent from the device 101, a B-phase AC wave for driving the vibration wave motor 106 is generated. The AC waves of the A phase and the B phase are drive voltage signals having the same frequency and a phase difference of 90 °, and the voltage amplitude is about 300V.

In FIG. 3, 700a, 700b, 700
c and 700d are FETs for switching. FET
The 700a and the FET 700b are FEs for generating an A-phase drive signal.
FET 700c and FET 700d are FETs for generating a B-phase drive signal. The pulse signals A1, A2, B1 and B2 are supplied to the gates of the FETs 700a to 700d, and the sources are grounded.

701a and 701b are transformers with a center tap. The power source voltage 1 is applied to the center tap electrode on the primary side of the transformer 701a,
A power supply voltage 2 is applied to the center tap electrode on the primary side of 1b. The power supply voltage 1 is a DC voltage output from the fixed power supply unit 104 shown in FIG. 1, and is 24V in the present embodiment. The power supply voltage 2 is a DC voltage output from the variable power supply unit 105 shown in FIG. 1, and has a configuration in which the voltage value can be changed. Transformer 701
FETs 700a, 700b, 700c and 7 are provided on the two electrodes other than the center tap electrodes of a and 701b, respectively.
The drain of 00d is connected.

The pulse signal A1 output from the pulse generator 101 drives the FET 700a, and the pulse signal A2 drives the FET 700b. As a result, a current alternately flows from the center tap electrode to the other two electrodes on the primary side of the transformer 701a. An AC signal corresponding to the step-up rate of the transformer 701a is generated on the secondary side of the transformer 701a. This becomes the A-phase AC wave output. Similarly, a B-phase AC wave output is also generated.

A four-phase pulse signal A as shown in FIG.
By using 1, A2, B1, and B2 as the gate signals of the FETs 700a to 700d, the A-phase AC wave and the B-phase AC wave having a phase difference of 90 ° with each other on the secondary sides of the transformers 701a and 701b. And are output.
The A-phase AC wave output and the B-phase AC wave output are input to the vibration wave motor 106 shown in FIG.

Returning to FIG. 1, the vibration wave motor 106 is driven by the above-described principle by the A-phase and B-phase AC wave signals having such a phase difference of 90 °.

Reference numeral 111 is a speed difference detecting section, which uses the pulse signal output from the encoder 110 connected to the output shaft of the vibration wave motor 106.
Detects the rotation speed of. Then, the speed difference Δv between the detected rotation speed and the command speed sent in advance from the target value command unit 120 is detected and output to the frequency setting unit 112.

Frequency setting unit 11 to which the speed difference Δv is input
2 creates a frequency increasing / decreasing manipulated variable according to the speed difference Δv. That is, in general, the vibration wave motor has a characteristic that the rotation speed gradually decreases as the frequency increases in a frequency range in which the frequency of the applied AC wave signal is higher than the resonance frequency. Used for control. Specifically, if the detected rotation speed is faster than the command speed, the frequency increase / decrease operation amount that changes the frequency of the AC wave signal to the higher side and to the lower frequency is created to make the detected rotation speed approach the command speed. In this way, the frequency increasing / decreasing manipulated variable is sent to the pulse generator 101. The pulse generator 101 changes the predetermined frequency of the start signal sent from the frequency setting unit 112 after starting the driving of the vibration wave motor 106 by this frequency increasing / decreasing operation amount, and based on the changed frequency, the four-phase Pulse signals A1, A2, B
Create 1 and B2.

Thus, the closed loop control is performed, and the rotation speed of the vibration wave motor 106 converges to the command speed at a speed according to the control parameter.

In this embodiment, the vibration wave motor 10
In addition to the drive frequency, the pulse widths of the four-phase pulse signals A1, A2, B1, and B2 are used as the manipulated variables for controlling the rotation speed of No. 6.

By the way, as described above, the application of the A-phase and B-phase AC wave signals to the elastic body of the vibration wave motor 106
Two standing waves are generated, and a traveling wave is generated by combining these standing waves, and the vibration wave motor 106 is driven. The two standing waves have different peak values of the two standing waves due to the deviation of the boosting ratio of the transformers 701a and 701b in the boosting units 102 and 103, the variation in the characteristics of the piezoelectric element in the vibration wave motor 106, and the like. As a result, the traveling wave becomes uneven. The unevenness of the traveling wave may cause uneven wear of the rotor in the vibration wave motor 106, resulting in shortening the life of the vibration wave motor 106.

In the present embodiment, the following control is added in order not to reduce the life of the vibration wave motor 106.

In FIG. 1, booster 102 and booster 10
The A-phase and B-phase AC wave signals respectively output from 3 are
It is input to the vibration wave motor 106, and is also input to the detection unit 107 and the detection unit 108 that detect the peak value. Since the amplitudes of these AC wave signals are about 300 V, the detection unit 107 and the detection unit 108 detect the peak value by resistance voltage division or voltage conversion by a transformer. The peak values of the A-phase and B-phase AC wave signals respectively detected by the detection unit 107 and the detection unit 108 are calculated by the comparison unit 1.
It is compared with 09. When the peak value of the B-phase AC wave signal output from the booster 103 is larger than the peak value of the A-phase AC wave signal output from the booster 102 as a result of the comparison in the comparator 109, the variable power supply unit The power supply voltage 2 supplied to the boosting unit 103 is reduced by controlling 105. On the contrary, when the peak value of the A-phase AC wave signal output from the booster 102 is larger than the peak value of the B-phase AC wave signal output from the booster 103, the variable power supply unit 105 is controlled to boost the voltage. The power supply voltage 2 supplied to the unit 103 is increased. By this closed loop, the peak value of the AC wave signal of the A phase and the peak value of the AC wave signal of the B phase are controlled to be equal, and as a result, it is possible to prevent the life of the vibration wave motor 106 from being shortened.

The variable power supply unit 105 can be simply constructed, for example, by combining a switching regulator and a variable resistor provided at the output of the switching regulator.

The operation of the vibration wave motor drive control device having such a configuration will be described below with reference to FIG.

FIG. 4 is a flow chart showing the operation procedure of the vibration wave motor drive control device in the first embodiment.

When this operation is started in step S201, the rotational speed control operation of the vibration wave motor 106 after step S202 and each peak value control operation of the A-phase and B-phase AC wave signals after step S208 are performed in parallel. Is done.

In step S202, the target value command unit 12
The frequency setting unit 112 which has been sent a speed command from 0 sends a signal having a frequency corresponding to the command speed (target speed) to the pulse generator 101.

In step S203, the pulse generator 10
1 is a 4-phase pulse signal A1, A2, B based on the received signal
1 and B2 are generated and the pulse signals A1 and A2 are output to the booster unit 10.
2, the pulse signals B1 and B2 are sent to the booster 103. The booster 102 generates an A-phase AC wave signal, and the booster 103
Generates a B-phase AC wave signal, which drives the vibration wave motor 106.

In step 204, the speed difference detecting section 111
Is an encoder 1 attached to the vibration wave motor 106
Using the pulse signal from 10, the oscillatory wave motor 106
Of the detected rotation speed and the speed difference Δ between the detected rotation speed and the command speed previously sent from the target value command unit 120.
v is detected and output to the frequency setting unit 112.

In step S205, if the detected speed difference Δv is positive, that is, if the rotation speed of the vibration wave motor 106 is faster than the speed instructed by the target value command unit 120, the process proceeds to step S206 and the frequency setting unit 112 is operated.
However, the rotation speed of the vibration wave motor 106 is reduced by setting the frequency of the signal sent to the pulse generator 101 high. On the contrary, when the detected speed difference Δv is negative, that is, when the rotation speed of the vibration wave motor 106 is slower than the speed commanded by the target value command unit 120, step S2
07, the frequency setting unit 112 causes the pulse generator 10
The rotation speed of the vibration wave motor 106 is increased by setting the frequency of the signal sent to 1 to low.

After executing steps S206 and S207, the process returns to step S203.

On the other hand, in step S208, the detection unit 10
Reference numerals 7 and 108 detect the peak values of the A-phase and B-phase AC wave signals output from the boosting units 102 and 103, respectively.

In step S209, the detected peak values are compared with each other.

In step S210, as a result of the comparison, if the difference between the peak values is positive, that is, if the peak value of the B-phase AC wave signal is larger than the peak value of the A-phase AC wave signal, the process proceeds to step S211, and the variable power supply is supplied. The power supply voltage 2 output from the unit 105 is set low. On the contrary, when the difference between the peak values is negative, that is, when the peak value of the A-phase AC wave signal is larger than the peak value of the B-phase AC wave signal, step S2
In step 12, the power supply voltage 2 output from the variable power supply unit 105 is set high.

After executing steps S211, S212, the process returns to step S208.

As described above, in the first embodiment, the peak value of the A-phase AC wave signal and the peak value of the B-phase AC wave signal are controlled to be equal to each other. It is possible to prevent the life of the motor 106 from being shortened.

(Second Embodiment) FIG. 7 is a block diagram showing the configuration of a second embodiment of a vibration wave motor drive control device according to the present invention. Since the configuration of the second embodiment is basically the same as that of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

In the vibration wave motor drive control device 300 according to the second embodiment, the peak value of the A-phase AC wave signal and the peak value of the B-phase AC wave signal are detected inside the vibration wave motor 302. It is like this.

That is, in a vibration wave motor, generally, an AC voltage is applied to the piezoelectric element to distort the piezoelectric element, thereby causing the elastic body to vibrate and rotate the rotor. By the way, such a piezoelectric element generally has the property of generating a voltage according to the amount of strain when mechanical strain is applied. Therefore, when the A-phase and B-phase AC wave signals are applied to the piezoelectric element in the vibration wave motor 302, and the strain corresponding to the applied voltage occurs in the piezoelectric element, the piezoelectric element outputs A
A weak voltage proportional to each peak value of the AC wave signals of the phase B and the phase B can be detected. If these weak voltages are sent to the comparison unit 109, the peak value of the A-phase AC wave signal and the peak value of the B-phase AC wave signal can be made equal, as in the first embodiment. As a result, it is possible to prevent the life of the vibration wave motor 302 from being shortened.

(Other Embodiments) In the first and second embodiments, the vibration wave motor drive control device 10 is used.
Although 0 and 300 are configured by hardware, instead of this, the vibration wave motor drive control device is configured by a control device including a processor, and the control device controls the first or second embodiment. You may make it implement | achieve the function in.

When the function of the vibration wave motor drive control device is realized by software, a storage medium storing a program code of software for realizing the function of each of the above-described embodiments is supplied to the system or device. It goes without saying that the present invention can also be achieved by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. .

As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk,
Hard disk, optical disk, magneto-optical disk, CD-
ROM, CD-R, magnetic tape, non-volatile memory card, ROM, etc. can be used.

Further, by executing the program code read by the computer, not only the functions of the above-described respective embodiments are realized, but also the OS and the like running on the computer based on the instructions of the program code. Does some or all of the actual processing, and the functions of the above-described embodiments are realized by the processing,
Needless to say, it is included in the present invention.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code, It is needless to say that the present invention also includes a case where the CPU or the like included in the function expansion board or the function expansion unit performs a part or all of the actual processing and the processing realizes the functions of the above-described embodiments. Yes.

[0075]

As described above in detail, according to the present invention, a plurality of AC signals having different phases are generated on the basis of a plurality of pulse signals having different phases, and an AC signal is generated to be applied to the electric-mechanical energy conversion element. Means for detecting the respective peak voltages of the plurality of alternating current signals, and controlling the alternating current signal generating means so that the detected respective peak voltages become equal.

As a result, uneven wear of the friction material on the rotor in the vibration wave motor can be prevented, and the life of the vibration wave motor can be extended.

[Brief description of drawings]

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

FIG. 2 is a timing chart showing four-phase pulse signals A1, A2, B1, B2.

FIG. 3 is a circuit diagram showing an internal configuration of a booster unit.

FIG. 4 is a flowchart showing an operation procedure of the vibration wave motor drive control device in the first embodiment.

FIG. 5 is a cross-sectional view showing an overall schematic configuration of a color image forming apparatus equipped with a vibration wave motor.

FIG. 6 is a diagram showing a connection state between a photosensitive drum and a vibration wave motor.

FIG. 7 is a second vibration wave motor drive control device according to the present invention.
3 is a block diagram showing the configuration of the embodiment of FIG.

[Explanation of symbols]

100 Vibration Wave Motor Drive Control Device 101 Pulse Generator (Pulse Generating Means) 102 Boosting Unit (AC Signal Generating Means, First AC Signal Generating Means) 103 Boosting Unit (AC Signal Generating Means, Second AC Signal Generating Means) 104 Fixed Power Supply Unit 105 Variable Power Supply Unit (Control Means, Variable Means) 106 Vibration Wave Motor 107 Detection Unit (Detection Means) 108 Detection Unit (Detection Means) 109 Comparison Unit (Control Means) 110 Encoder 111 Speed Difference Detection Unit 112 Frequency setting unit 120 Target value command unit 700a FET (first switching element) 700b FET (second switching element) 700c FET (third switching element) 700d FET (fourth switching element) 701a Transformer (first Transformer) 701b Transformer (second transformer)

Claims (15)

[Claims] 1. A drive control device for a vibration wave motor in which an AC signal is applied to an electromechanical energy conversion element to excite a vibrating body to obtain a driving force, and a plurality of pulse signals having different phases are generated. Pulse generating means, based on the plurality of pulse signals generated by the pulse generating means, a plurality of AC signals having different phases, AC signal generating means for applying to the electro-mechanical energy conversion element, the plurality of An oscillating wave characterized by having detection means for detecting each peak voltage of the AC signal and control means for controlling the AC signal generation means so that the peak voltages detected by the detection means become equal. Motor drive controller. 2. A drive control device for a vibration wave motor in which an AC signal is applied to an electric-mechanical energy conversion element to excite a vibrating body to obtain a driving force, and four pulse signals having different phases are generated. Pulse generation means, and first AC signal generation means for generating a first AC signal based on the first and second pulse signals generated by the pulse generation means and applying it to the electro-mechanical energy conversion element. Second AC signal generating means for generating a second AC signal based on the third and fourth pulse signals generated by the pulse generating means and applying the second AC signal to the electro-mechanical energy conversion element; Detecting means for detecting the respective peak voltages of the first and second alternating current signals, and the first and second alternating current signal generating means so that the difference between the respective peak voltages detected by the detecting means becomes zero. Vibration wave motor drive control apparatus characterized by a control means for controlling at least one operation of the means. 3. The first pulse signal and the second pulse signal have a phase difference of 180 degrees, and the third pulse signal and the fourth pulse signal have a phase difference of 180 degrees. 3. The vibration wave motor drive control device according to claim 2, wherein the first pulse signal and the third pulse signal have a phase difference of 90 degrees. 4. The first alternating-current signal generating means inputs the first pulse signal and the second pulse signal to each control terminal, and grounds one end of each controlled terminal, First and second switching elements that perform switching by the first and second pulse signals, respectively, and the other terminals of the controlled terminals of the first and second switching elements at both terminals on the primary side. A first transformer that is connected to each other and is supplied with a first predetermined voltage to the center tap terminal on the primary side and that outputs the first AC signal from the secondary side. The vibration wave motor drive control device according to claim 2 or claim 3. 5. The second AC signal generating means is configured such that the third pulse signal and the fourth pulse signal are input to each control terminal, and one end of each controlled terminal is grounded. Third and fourth switching elements that perform switching by the third and fourth pulse signals, respectively, and both terminals of the primary side have respective other ends of the controlled terminals of the third and fourth switching elements. A second transformer that is connected to each other and is supplied with a second predetermined voltage to the center tap terminal on the primary side, and outputs the second AC signal from the secondary side. The vibration wave motor drive control device according to any one of claims 2 to 4. 6. The vibration wave according to claim 5, wherein the control unit includes a variable unit that changes the second predetermined voltage based on a difference between peak voltages detected by the detection unit. Motor drive controller. 7. The detecting means is associated with strains respectively generated in the electro-mechanical energy conversion element by applying the first and second AC signals to the electro-mechanical energy conversion element. 3. Each of the voltages generated in the electro-mechanical energy conversion element is detected, and each peak voltage of the first and second AC signals is detected based on each voltage. 7. The vibration wave motor drive control device according to any one of 6 above. 8. A pulse generating means for generating a plurality of pulse signals having different phases, and a plurality of alternating current signals having different phases based on the plurality of pulse signals generated by the pulse generating means to generate electro-mechanical energy. In a drive voltage control method applied to a vibration wave motor drive control device comprising an AC signal generating means for applying to a conversion element, a detection step of detecting each peak voltage of the plurality of AC signals, and in the detection step And a control step of controlling the AC signal generating means so that the detected peak voltages become equal to each other. 9. A pulse generating means for generating four pulse signals having different phases, and a first AC signal based on the first and second pulse signals generated by the pulse generating means, and an electro-mechanical device. A first alternating current signal generating means applied to the energy converting element, and a third alternating current signal generating means generated by the pulse generating means.
And a second AC signal generating means for generating a second AC signal based on the fourth pulse signal and applying the second AC signal to the electro-mechanical energy conversion element. In the control method, a detection step of detecting each peak voltage of the first and second AC signals, and a difference between the peak voltages detected in the detection step are zero, And a control step of controlling the operation of at least one of the AC signal generating means. 10. The first pulse signal and the second pulse signal have a phase difference of 180 degrees, and the third pulse signal and the fourth pulse signal have a phase difference of 180 degrees. 10. Further, the first pulse signal and the third pulse signal have a phase difference of 90 degrees.
The drive voltage control method described. 11. The detecting step is according to strains respectively generated in the electro-mechanical energy conversion element by applying the first and second AC signals to the electro-mechanical energy conversion element. Each voltage generated in the electro-mechanical energy conversion element is detected, and the first voltage is detected based on each voltage.
10. The drive voltage control method according to claim 9, wherein each peak voltage of the second AC signal is detected. 12. A pulse generating means for generating a plurality of pulse signals having different phases, and a plurality of alternating current signals having different phases based on the plurality of pulse signals generated by the pulse generating means to generate electro-mechanical energy. In a program for causing a computer to execute a drive voltage control method applied to an oscillatory wave motor drive control device including an AC signal generation unit that applies to a conversion element, the drive voltage control method, the plurality of AC signals And a control step of controlling the alternating-current signal generating means so that the peak voltages detected in the detection step are equal to each other. 13. A pulse generating means for generating four pulse signals having different phases, and a first alternating current signal based on the first and second pulse signals generated by the pulse generating means to generate an electro-mechanical device. First AC signal generating means applied to the energy converting element, and second AC signals are generated based on the third and fourth pulse signals generated by the pulse generating means, and the electric-mechanical energy converting element is generated. A program for causing a computer to execute a drive voltage control method applied to a vibration wave motor drive control device comprising a second AC signal generating means for applying, the drive voltage control method comprising: A detection step of detecting each peak voltage of the AC signal of No. 2, and the first and second so that the difference between the peak voltages detected in the detection step becomes zero. And a control step for controlling the operation of at least one of the AC signal generating means. 14. A pulse generating means for generating a plurality of pulse signals having different phases, and a plurality of alternating current signals having different phases based on the plurality of pulse signals generated by the pulse generating means to generate electro-mechanical energy. In a computer-readable storage medium, which stores a drive voltage control method applied to an oscillatory wave motor drive control device having an AC signal generating unit for applying to a conversion element as a program, the drive voltage control method includes: It is characterized by further comprising a detection step of detecting each peak voltage of a plurality of AC signals, and a control step of controlling the AC signal generation means so that the peak voltages detected in the detection step become equal to each other. Storage medium. 15. A pulse generator for generating four pulse signals having different phases, and a first AC signal based on the first and second pulse signals generated by the pulse generator, and an electro-mechanical device. First AC signal generating means applied to the energy converting element, and second AC signals are generated based on the third and fourth pulse signals generated by the pulse generating means, and the electric-mechanical energy converting element is generated. A computer-readable storage medium storing, as a program, a drive voltage control method applied to an oscillatory wave motor drive control device having a second AC signal generating means for applying, the drive voltage control method comprising: The detection step of detecting the respective peak voltages of the first and second AC signals, and the difference between the respective peak voltages detected in the detection step become zero. As described above, a storage medium having a control step of controlling the operation of at least one of the first and second alternating-current signal generating means.