JPH11215861A - Driving control equipment of vibrating motor and equipment using vibration type motor as driving source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption at the time of start and prevent damage of a driving circuit, by controlling the output of an AC signal for driving in order that an electric-mechanical energy transducer for driving may be gently charged at the time of start of a vibrating motor. SOLUTION: Monitoring a result obtained by a resistance element 49 and a differential amplifier 29, and preventing a detected current from exceeding a value, a microcomputer 21 gives a command to a 4-phase oscillator 22 in such a manner that width of input pulses at the time of starting is gradually increased. The 4-phase oscillator 22 gives a signal whose phase is shifted by 90 deg. to each of the switching elements 23-26. The elements 23-26 are switched and switch the primary side of a transformer whose one side is connected with a power source Vcc. The secondary side drives a vibration wave motor USM, with a voltage stepped up in accordance with the switching width. While the input current is monitored, the width of input pulses are gradually increased, so that a usual large current can be restrained to be small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a vibration type motor and a device using the vibration type motor as a driving source.

[0002]

2. Description of the Related Art As is well known, a vibration type motor such as a vibration wave motor applies a high frequency signal to a piezoelectric element as an electro-mechanical energy conversion element of a vibrating body by applying an alternating signal to the element. A non-electromagnetic drive motor configured to generate vibration and extract its vibration energy as a continuous mechanical motion.This operating principle has already been described in many patents.
By applying a drive alternating signal to a piezoelectric element as an electro-mechanical energy conversion element for driving a vibrating body of a vibrating wave motor, a predetermined vibration mode (standing by one or more bending vibrations) is applied to the vibrating body. (Wave) is excited, and the vibration mode generated at a position different from the vibration mode has an appropriate time phase difference to form an elliptical motion on the surface particles of the vibration body, and the vibration body and the vibration body The contact body that comes into pressure contact with the contact body is frictionally driven relatively by the elliptical motion.

FIG. 10 shows a cross-sectional view of a conventional vibration wave motor. In the drawing, reference numeral 1 denotes a ring-shaped metal elastic body made of a flexible material such as stainless steel or phosphor bronze, and a piezoelectric element group in which two groups of a plurality of polarized piezoelectric elements are formed in a ring shape on one end surface thereof. 2 are concentrically bonded to each other, and a slider member 3 made of resin, metal, ceramic or the like bonded to the other end surface is used as a vibrator, and both ends of the piezoelectric element group 2 are generated so that traveling waves are generated on the surface of the elastic body 1. Electrodes are arranged on the surface and subjected to polarization processing. On the surface of the elastic body 1 on the slider material side, a plurality of comb-shaped grooves are regularly formed in the circumferential direction to increase motor efficiency.

A flexible substrate 4 for taking out a drive signal and a signal from a sensor unit for detecting a vibration state of a motor provided on the piezoelectric element is fixed to a surface opposite to the piezoelectric element group 2. The inner peripheral portion of the elastic body 1 has a thin disk shape, and is fixed to the base 5 on the inner peripheral side by bonding or screws. A moving body 6 is brought into pressure contact with the surface of the slider member 3 via a vibration isolating rubber 7 on the same axis as the elastic body 1 by a leaf spring 8. The inner diameter of the leaf spring 8 is tightly fitted with a shaft 10. Disc flange 9
Has been fixed by. The shaft 10 is fitted and inserted into the bearings 11 and 12 fitted to the base, and retains the pressing force by the retaining ring 13. The spacer 14 applies a preload to the bearing 11 to reduce the amount of whirling of the shaft.

FIG. 11 shows a drive circuit when such a vibration wave motor is used. A-phase and B-phase signals are applied via a flexible substrate 4. 21 is a control circuit for driving and controlling the motor (hereinafter referred to as a control microcomputer), 22 is a four-phase oscillator for generating a four-phase alternating voltage,
23, 24, 25, and 26 are switching elements for switching a power supply voltage with an alternating voltage from the oscillator 22;
Reference numerals 7 and 28 denote transformers for boosting the power supply voltage while matching the impedance with the motor.

Reference numeral 40 denotes a capacitor for smoothing the voltage of the power supply, and reference numerals 41 to 48 denote resistance elements for controlling the drive current of the switching elements 23 to 26.

[0007] Then, as shown in FIG. 12, a high alternating voltage is applied to the vibration wave motor by switching the power supply voltage with the switching elements 23 to 26 using the four-phase signal output from the four-phase oscillator 22. , The motor is driven.

[0008]

In such a driving circuit for a vibration wave motor, when a switching voltage is applied to the motor and started immediately as in the conventional example, the electromechanical energy conversion element is a capacitive element. At startup, when the charge is not yet fully charged,
Since the rapid charging of the electric charge is started, a sudden current flows in the drive power supply, and a large amount of power is consumed, and sometimes the circuit components are damaged.

An object of the first invention according to the present application is to provide a driving apparatus for a vibration-type motor that can reduce power consumption at the time of starting the vibration-type motor and can prevent damage to a driving circuit. It is.

A second object of the present invention is to provide an apparatus for driving a driven body by using one or a plurality of vibration type motors as a driving source, and to drive a vibration type motor which consumes less power and does not cause circuit breakage. It is intended to provide a source device.

[0011]

A first configuration for realizing the object of the first invention according to the present application is to output a driving alternation signal applied to a driving electro-mechanical energy conversion element of a vibration type motor. A driving device for a vibration-type motor, comprising a control unit for controlling the output of the driving alternation signal so that the electric charge to the driving electro-mechanical energy conversion element becomes slower when the vibration-type motor is started. is there.

A second configuration for realizing the object of the first invention according to the present invention is a driving device for a vibration type motor for outputting a driving alternation signal applied to an electro-mechanical energy conversion element for driving a vibration type motor. And a control means for controlling the output of the driving alternation signal to gradually increase based on a current value of a driving power supply at the time of starting the vibration type motor.

A third configuration for realizing the object of the first invention according to the present application is a driving apparatus for a vibration type motor for outputting a driving alternation signal applied to a driving electro-mechanical energy conversion element for the vibration type motor. , A first frequency higher than a resonance frequency at which the vibration type motor does not operate, and a second frequency at which the vibration type motor operates are set, and
And control means for driving at the second frequency when the output of the driving alternation signal at the start of the start at the frequency of not more than a predetermined value.

A fourth configuration for realizing the object of the first invention according to the present application is a driving apparatus for a vibration type motor which outputs a driving alternation signal applied to an electro-mechanical energy conversion element for driving a vibration type motor. At startup, one of the two-phase driving alternating signals applied with a phase difference to the driving electric-mechanical energy
After the application to the mechanical energy conversion element, there is provided control means for applying the other to the electro-mechanical energy conversion element.

As the configuration of the control means, the pulse width of the alternating signal at the time of starting is gradually widened, and the voltage of the alternating signal at the time of starting is gradually increased.

A first configuration for realizing the object of the second invention according to the present application includes a driving device for a vibration type motor having any one of the above-described configurations, and a driven body using the vibration type motor as a driving source. Is driven.

A second configuration for realizing the object of the second invention according to the present application is an apparatus using a vibration type motor for driving a driven body by using a plurality of vibration type motors as a drive source. At the time of starting, the starting of the plurality of vibration type motors is shifted.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a circuit diagram of a driving device for a vibration type motor according to a first embodiment of the present invention.

Reference numeral 21 denotes a control circuit (hereinafter referred to as a control microcomputer) for driving and controlling a vibration wave motor USM as a vibration type motor; 22, a four-phase oscillator for generating a four-phase alternating voltage; , 26 are switching elements for switching the power supply voltage with the alternating voltage from the oscillator 22, and 27, 28 are transformers for boosting the power supply voltage while matching the impedance with the vibration wave motor USM.

Reference numeral 40 denotes a capacitor for smoothing the voltage of the power supply, and reference numerals 41 to 48 denote resistance elements for controlling the drive current of the switching elements 23 to 26.

The present embodiment is different from the conventional circuit shown in FIG.
A resistance element 49 for detecting a current flowing into the circuit 8 and a differential amplifier 29 are provided.

The microcomputer 21 of the drive circuit is configured to give a command value to the four-phase oscillator 22 in accordance with the pulse width of the pulse signal determined based on the detection result.

In FIG. 2, I indicates a pulse input signal at the time of starting the vibration wave motor used in the present embodiment. The state of the current flowing at this time is shown in comparison with the conventional (dotted line). .

As can be seen from FIG. 1, the microcomputer 21 gradually increases the pulse width of the input pulse at the time of startup so that the detected current does not exceed a certain value while observing the results obtained by the resistance element 49 and the differential amplifier 29. To spread to 4
A command is given to the phase oscillator 22. Then four-phase oscillator 2
2, the switching elements 23 to 26 are switched at the timing, and the primary side of the transformer connected to the power supply (Vcc) is switched at one of the switching elements 23 to 26 at the timing. I do. Then, on the secondary side, the vibration wave motor USM is driven by the voltage boosted according to the switching width.

As described above, in this embodiment, by gradually increasing the pulse width of the input pulse while observing the state of the input current, it is possible to suppress the current that has conventionally flown large.

(Second Embodiment) FIG. 3 is a drive circuit diagram of a vibration wave motor used in a second embodiment.

The difference between the present embodiment shown in FIG. 3 and the conventional drive circuit shown in FIG. 11 is that a power supply voltage control circuit for controlling the voltage of the power supply (Vcc) in accordance with a command from the microcomputer 21 in the present embodiment. The output from 30 is supplied to the transformers 27 and 28 via the resistance element 49,
The transformers 27 and 2 are formed by the resistance element 49 and the differential amplifier 29.
8 is detected, and the detection result is sent to the microcomputer 21.
Output to

FIG. 4 shows a pulse signal (without changing the pulse width) at the time of starting the vibration wave motor used in the present embodiment. The state of the current flowing at this time is compared with that of the conventional (dotted line). Is shown.

As shown in FIG. 4, the microcomputer 21 gradually increases the pulse voltage of the input pulse at the time of startup so that the detected current does not exceed a certain value while observing the results detected by the resistance element 49 and the differential amplifier 29. Is given to the power supply voltage control circuit 30 so as to increase the power supply voltage. Then, a switching voltage as shown in FIG. 4 is applied to the primary sides of the transformers 27 and 28, and a frequency voltage obtained by boosting the switching voltage is applied to the vibration wave motor.

As described above, by gradually increasing the pulse voltage of the input pulse on the primary side of the transformer while observing the state of the input current, it is possible to reduce the current that has conventionally flowed large.

(Third Embodiment) FIG. 5 shows frequency and rotation speed characteristics for illustrating a method of driving a vibration wave motor according to a third embodiment. FIG. 6 shows a pulse signal when the vibration wave motor used in the third embodiment is started.
The state of the current flowing at this time is also shown in comparison with the conventional (dotted line). Note that the circuit configuration is the same as that of the first embodiment shown in FIG. 1, and the difference lies in the processing described below by the microcomputer 21.

As shown in FIGS. 5 and 6, the microcomputer 21 has a frequency f higher than the frequency at which the motor starts rotating.
₁ is set as the starting frequency. Then, while viewing the result detected by the resistor element 49 and the differential amplifier 29, without common sweep control to reduce the drive frequency continuously, to jump to a frequency f ₀ used in ordinary driving.

In such a case, since there is no power consumed for driving the motor as compared with the case where the motor is started at the normal frequency f ₀ , the rush current to the circuit (transformer) and, consequently, the piezoelectric element of the vibration wave motor is reduced. Can be reduced. Also,
It means that the charge is charged to the driving piezoelectric element and Starting frequency f ₁ is started, then the driving frequency f
Even if it is _0, there is almost no inrush current in the driving piezoelectric element.

Therefore, after starting at the frequency f ₁ higher than the frequency at which the vibration wave motor USM rotates, it is confirmed that the value of the rush current is equal to or less than a certain value.
Since start at _0, it is possible to start the vibration wave motor USM without increasing the rush current compared with driving circuit of the conventional example shown in FIG. 11.

(Fourth Embodiment) FIG. 7 shows a pulse signal when the vibration wave motor used in the fourth embodiment is started. The state of the current I flowing at this time is also shown in comparison with the conventional case (dotted line). The circuit configuration is the same as that of FIG. 1 except for the processing of the microcomputer 21.

As shown in FIG. 7, in this embodiment, the two-phase voltage applied to the driving piezoelectric element of the vibration wave motor USM is monitored while observing the result of the detection current detected by the resistance element 49 and the differential amplifier 29. After applying one of the voltages (A phase, B phase), the other voltage is applied. For example, a driving pulse is generated one cycle ahead only for A and ΔA, and thereafter a driving pulse is generated for B and ΔB.

As described above, by inputting one of the voltages to be applied to the two drive phases and then inputting the other while observing the state of the input current, the rush current to the circuit is divided and the current is reduced as compared with the conventional case. The motor can be driven by the current.

According to the present embodiment, the inrush current at the time of starting can be easily reduced without changing the pulse width, the power supply voltage and the starting frequency.

(Fifth Embodiment) FIG. 8 is a schematic diagram showing an embodiment of a paper feeder using a vibration wave motor. Reference numeral 51 denotes a roller for feeding paper, and a bearing 52 having an appropriate preload applied to the end on the opposite side to where the vibration wave motor is coupled.
Has been arranged. Also, on the opposite side of the motor roller,
A pulse plate 53 for detecting the rotation speed and rotation angle of the motor, an optical detection element 54, and a detection element mounting case 55 are provided. Since the pulse plate 53 is directly attached to the motor shaft, the accuracy is good.

For coupling the motor and the roller, the motor shaft 10 is lightly pressed into a hole provided in the roller 51 and further fixed from the side with a set screw 56. By using the drive circuit of the present invention with such a device configuration, a device with high circuit efficiency can be provided.

(Sixth Embodiment) FIG. 9 shows a sixth embodiment of the present invention.
1 is a schematic diagram of an image forming apparatus using a plurality of vibration wave motors according to an embodiment.

Hereinafter, the configuration of the color image forming apparatus will be described with reference to FIG.

First, the configuration of the reader unit will be described.

In FIG. 9, 101 is a CCD, 311 is a substrate on which the CCD 101 is mounted, 312 is a printer processing unit, 301 is a platen glass, 302 is a document feeder,
03 and 304 are light sources for illuminating the original, 305 and 306 are reflectors for condensing light from the light sources (303 and 304) on the original, 307 to 309 are mirrors, 310 is reflected light or projected light from the original on the CCD 101. 314 are light sources 303 and 304 and reflectors 305 and 30
Reference numeral 315 denotes a carriage accommodating the mirrors 308 and 309, and 313 denotes an interface unit with another IPU or the like.

The carriage 314 is moved at a speed V, and the carriage 315 is mechanically moved at a speed V / 2 in a direction perpendicular to the electrical scanning (main scanning) direction of the CCD 101, thereby scanning the entire surface of the document (sub scanning). ).

Documents on the platen glass are light sources 303 and 30
4 is reflected, and the reflected light is guided to the CCD 101 and converted into an electric signal. Then, the electric signal (analog image signal) is input to the image processing unit 312 and converted into a digital signal. After the converted digital signal is processed, it is sent to a printer unit described later and used for image formation.

Next, the configuration of the printer unit will be described.

In FIG. 9, 317 is a magenta color (M)
An image forming unit 318 is a cyan (C) image forming unit, 31
9 is a yellow (Y) image forming unit, 320 is black (K)
Since the respective configurations of the image forming units are the same, the M image forming unit 317 will be described, and the description of the other image forming units will be omitted.

In the M image forming unit 317, reference numeral 342 denotes a photosensitive drum, on which a latent image is formed by light from the LED array 210. A primary charger 321 charges the surface of the photosensitive drum 342 to a predetermined potential to prepare for forming a latent image. Reference numeral 322 denotes a developing device, and the photosensitive drum 342
The upper latent image is developed to form a toner image. The developing device 322 includes a sleeve 345 for applying a developing bias to develop. Reference numeral 323 denotes a transfer charger which discharges from the back of the transfer material transport belt 333 to transfer the toner image on the photosensitive drum 342 to the transfer material transport belt 33.
3. Transfer to a transfer material such as recording paper on 3. In this embodiment, the transfer efficiency is good, so that the conventionally used cleaner portion is not provided, but it goes without saying that there is no problem even if the cleaner portion is attached.

Next, a procedure for forming an image on a recording paper or the like will be described. The recording papers and the like stored in the cassettes (340, 341) are supplied onto the transfer material transport belt 333 by sheet feed rollers 336, 337 one by one by pickup rollers 339, 338. The fed recording paper is charged by the adsorption charger 346. Reference numeral 348 denotes a transfer belt roller which drives the transfer belt 333 and
6, the recording paper or the like is charged, and the recording paper or the like is attracted to the transfer material transport belt 333. A paper edge sensor 347 detects the edge of the recording paper on the transfer material transport belt 333. The detection signal of the paper leading edge sensor is sent from the printer unit to the color reader unit, and is used as a sub-scan synchronization signal when a video signal is sent from the color reader unit to the printer unit.

Thereafter, the recording paper and the like are transferred to the transfer material transport belt 33.
3, the toner image is formed on the surface of the image forming units 317 to 320 in the order of MCYK.
The recording paper or the like that has passed through the K image forming unit 320 is separated from the transfer material transport belt 333 after the charge is removed by the charge removing charger 349 in order to facilitate separation from the transfer material transport belt 333. Reference numeral 350 denotes a peeling charger which prevents image disturbance due to peeling discharge when the recording paper or the like is separated from the transfer material transport belt 333. The separated recording paper or the like is charged by pre-fixing chargers 351 and 352 and then heat-fixed by a fixing device 334 to fix the toner image 335 in order to compensate for toner attraction and prevent image disturbance. Is discharged to the paper discharge tray.

Here, a vibration wave motor is used as a drive motor for rotating the photosensitive drums 342 to 345 and the transfer material conveying belt roller 348. In the image forming apparatus using such a plurality of vibration wave motors, the respective motors are not started at the same time, but are started at slightly different times. With such a starting method, a large current can be prevented from flowing from the power supply. And the first one
By using the configuration of the fourth embodiment, a device with higher circuit efficiency can be provided.

[0053]

According to the inventions according to the first to thirteenth aspects, at the time of startup, the electric-to-mechanical energy conversion element for driving the vibration type motor is not suddenly charged at once, and the driving power supply Current value does not increase, power can be saved, and breakage of the circuit can be prevented.

According to the fourteenth and fifteenth aspects of the present invention, it is possible to reduce the power consumption of the device and to prevent damage to the circuit.

[Brief description of the drawings]

FIG. 1 is a drive circuit diagram of a vibration wave motor according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing a pulse input signal and a current when the vibration wave motor of FIG. 2 is started.

FIG. 3 is a drive circuit diagram of a vibration wave motor according to a second embodiment of the present invention.

FIG. 4 is a waveform diagram showing a pulse input signal and a current when the vibration wave motor of FIG. 3 is started.

FIG. 5 is a diagram illustrating frequency and rotation speed characteristics according to a third embodiment of the present invention.

FIG. 6 is a waveform diagram showing a pulse input signal and a current when the vibration wave motor of FIG. 5 is started.

FIG. 7 is a waveform chart showing a pulse input signal and a current when the vibration wave motor according to the fourth embodiment is started.

FIG. 8 is a sectional view of a fifth embodiment of the present invention.

FIG. 9 is a schematic diagram of an image forming apparatus according to a sixth embodiment of the present invention.

FIG. 10 is a sectional view of a vibration wave motor.

FIG. 11 is a drive circuit diagram of a conventional vibration wave motor.

FIG. 12 is a waveform diagram showing a pulse input signal and a current when the vibration wave motor of FIG. 11 is started.

[Explanation of symbols]

 1: Elastic body 2: Piezoelectric element group 3: Slider material 4: Flexible substrate 5: Base 6: Moving body 7: Anti-vibration rubber 8: Leaf spring 9: Disk flange 10: Shaft 11, 12: Bearing 13: Retaining ring 14 : Spacer 21: Microcomputer 22: Four-phase oscillator 23, 24, 25, 26: Switching element 27, 28: Transformer 29: Differential amplifier 30: Power supply voltage control circuit 40: Capacitors 41 to 48: Resistance element 49: Resistance element 51 : Roller 52: bearing 53: pulse plate 54: optical detection element 55: detection element mounting case 56: set screw

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sada Hayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Jun Ito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the corporation

Claims (15)

[Claims] 1. A driving apparatus for a vibration type motor for outputting a driving alternation signal applied to a driving electro-mechanical energy conversion element for a vibration type motor, wherein the driving electro-mechanical energy conversion is performed when the vibration type motor is started. A driving device for a vibration-type motor, comprising: control means for controlling the output of the driving alternation signal so that the charge of the element is reduced gradually. 2. A vibration motor driving apparatus for outputting a driving alternation signal to be applied to a driving electro-mechanical energy conversion element for a vibration motor, wherein the vibration motor is activated based on a current value of a driving power supply. And a control means for controlling the output of the driving alternation signal so as to gradually increase. 3. A driving apparatus for a vibration-type motor for outputting a driving alternation signal applied to a driving electro-mechanical energy conversion element for driving the vibration-type motor, wherein the vibration-type motor has a first frequency higher than an inoperative resonance frequency.
And a second frequency at which the vibration type motor operates are set, and when the output of the driving alternation signal at the start of the start at the first frequency is equal to or less than a predetermined value, the second frequency is set. A driving device for a vibration-type motor, comprising: a control unit that drives the vibration-type motor. 4. A driving apparatus for a vibration-type motor for outputting a driving alternation signal to be applied to a driving electric-to-mechanical energy conversion element for a vibration-type motor. A control means for applying one of the two-phase driving alternating signals applied to the electro-mechanical energy conversion element and then applying the other to the electro-mechanical energy conversion element. A driving device for a vibration type motor. 5. The vibration motor driving device according to claim 1, wherein the control unit gradually widens a pulse width of the alternating signal at the time of starting. 6. A driving apparatus for a vibration-type motor, wherein the control means gradually increases the voltage of the alternating signal at the time of starting. 7. The driving apparatus for a new Ozu type motor according to claim 2, wherein the control means gradually increases the output of the alternating signal whose current value of the driving power supply does not exceed a predetermined value. . 8. The alternation signal is applied to the driving electro-mechanical energy conversion element via a transformer, and the control means detects a value of a current flowing through the transformer, and detects a primary current of the transformer. 3. A pulse width or a pulse voltage of an input pulse to the side is controlled.
4. A driving device for a vibration type motor according to claim 1. 9. The driving apparatus according to claim 8, wherein the control unit gradually increases a pulse width or a pulse voltage. 10. The method according to claim 8, wherein the control unit controls the pulse width or the pulse voltage such that a current value flowing to a primary side of the transformer does not exceed a predetermined value. Drive device for vibration motor. 11. A vibration type motor driving device for outputting a driving alternation signal applied to a driving type electro-mechanical energy conversion device for a vibration type motor, wherein the electro-mechanical energy conversion device is based on a current value of a driving power supply. A driving device for a vibration-type motor, further comprising control means for controlling a voltage of an alternating signal applied to the motor. 12. The apparatus according to claim 11, wherein said control means gradually increases the voltage of said alternating signal at the time of starting.
4. A driving device for a vibration type motor according to claim 1. 13. The driving device according to claim 11, wherein the control unit controls the voltage of the alternating signal so that the current value of the driving source does not exceed a predetermined value. . 14. A driving device for a vibration type motor according to claim 1, wherein a driven body is driven by using the vibration type motor as a driving source. A device that uses a vibration motor as a drive source. 15. An apparatus using a plurality of vibration-type motors as a drive source and a vibration-type motor for driving a driven body as a drive source, wherein the start-up of the plurality of vibration-type motors is shifted when the apparatus is started. A device using a vibration type motor as a driving source.