JP2001119968A - Vibration-type motor drive control device, drive control method, and record medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To blow out a fuse without allowing a device to malfunction, when one of vibration-type motors fails and an overcurrent flows. SOLUTION: In the drive control device of a plurality of vibration-type motors 102y, 102m, 102c, and 102k for driving each of a plurality of movable bodies (photorecept drums), a CPU 120 successively stats driving the plurality of vibration-type motors 102y, 102m, 102c, and 102k at a prescribed time interval, when it receives a command for simultaneously starting the plurality of movable bodies, thus separately starting each of the vibration-type motors, when the plurality of movable bodies are stated and hence suppressing the generation of the large inrush current of the vibration-type motors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration type motor drive control device, a drive control method, and a storage medium.
The present invention relates to a drive control device for a plurality of vibration motors that respectively drive a plurality of movable bodies, a drive control method applied to the drive control device, and a storage medium storing a program for executing the drive control method.

[0002] The vibration type motor drives a plurality of photosensitive drums constituting an image forming apparatus such as a copying machine.

[0003]

2. Description of the Related Art Conventionally, there is a vibration wave motor as a driving means having good rotation accuracy.

In a vibration wave motor, a piezoelectric element is bonded to one surface of an elastic body made of metal, for example, in an annular shape with an adhesive, and a driving piezoelectric element group formed on the piezoelectric element is provided with a phase shifter. By applying different AC voltages, two standing waves are excited on the elastic body, and a progressive vibration wave that is a bending vibration is formed by combining these standing waves. on the other hand,
On the other surface side of the elastic body, for example, a ring-shaped member is pressed through a pressing means such as a spring, and the member is moved by friction driving by a progressive vibration wave formed on the elastic body. Alternatively, the elastic body is moved. Further, the drive circuit has a drive pulse generation unit that generates an AC wave, and a control system that feeds back the rotation speed of the motor from an encoder attached to the motor.

[0005] This vibration wave motor has good rotation accuracy, has a strong property against transient load fluctuations, and is advantageous for color shift, pitch unevenness, and paper feed shock. It is being used for driving photosensitive drums and transfer belts.

Here, in a so-called four-drum type color image forming apparatus including a yellow image forming unit, a magenta image forming unit, a cyan image forming unit, and a black image forming unit, four drum driving units are driven. Conventionally, there is a device using a vibration type motor.

In such a conventional apparatus, four drum driving units are simultaneously driven when the apparatus is started.

[0008]

However, in the case where a vibration type motor is used for each of the drum driving units of the four-drum type color image forming apparatus, if these drum driving units are started up simultaneously, as shown in FIG. Thus, the inrush current increases. FIG. 4 is a diagram illustrating the rush current when the four photosensitive drums are simultaneously driven.

Therefore, it is necessary to set the rated capacity (fusing current value) of the fuse provided between the power supply and the drive control circuit of the vibration type motor to a value larger than the fusing current value required in a steady state. As a result, even if an abnormality occurs in one of the vibration type motors in the steady state and an overcurrent flows, the fuse may not be blown and a malfunction may occur in the device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and is designed to blow a fuse without causing a malfunction in a device when one of vibration type motors has an abnormality and an overcurrent flows. It is an object of the present invention to provide a vibration type motor drive control device, a drive control method, and a storage medium.

[0011]

According to a first aspect of the present invention, there is provided a drive control apparatus for a plurality of vibration type motors for driving a plurality of movable bodies, respectively. Receiving means for receiving a command for simultaneously activating the body, and driving for sequentially starting the drive with a predetermined time interval for each of the plurality of vibration-type motors when the receiving means receives the command. And a start control means.

According to a fifth aspect of the present invention, in the drive control method applied to a drive control device for a plurality of vibration type motors for driving a plurality of movable bodies, the plurality of movable bodies are simultaneously activated. A receiving step of receiving a command; and a drive start control step of, when receiving the command, sequentially starting driving of each of the plurality of vibration type motors at a predetermined time interval. And

Further, according to the present invention, a drive control method applied to a drive control device for a plurality of vibration type motors for driving a plurality of movable bodies is stored as a program and can be read by a computer. In the storage medium, the drive control method receives a command for simultaneously activating the plurality of movable bodies, and when receiving the command, sets a predetermined time interval for each of the plurality of vibration-type motors. Accordingly, a driving start control step of sequentially starting driving is provided.

[0014]

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

FIG. 3 is an internal configuration diagram showing the configuration of a four-drum type color copying machine.

In FIG. 3, reference numeral 401 denotes a printer unit;
Reference numeral 2 denotes a reader unit.

First, in the reader unit 402, 101 is a CCD (image pickup device), 300 is a liquid crystal panel which also serves as an operation unit and a display unit, 311 is a substrate on which the CCD 101 is mounted,
Reference numeral 312 denotes an image processing unit, 301 denotes a document table glass, 302 denotes a document feeder (DF), 303 and 304 denote light sources (halogen lamps or fluorescent lamps) for illuminating the document, and 305 and 3
Reference numeral 06 denotes a reflector for condensing the light from the light sources 303 and 304 on the original, reference numerals 307 to 309 denote mirrors, reference numeral 310 denotes a lens for condensing reflected light or projection light from the original on the CCD 101, and reference numeral 31 denotes a lens.
Reference numeral 4 denotes a carriage that houses the light sources 303 and 304, reflectors 305 and 306, and mirror 307. Reference numeral 315 denotes the mirror 30.
A carriage 313 for accommodating 8,309 is an interface unit with another intelligent processing unit (IPU) or the like. The carriage 314
Is speed V, carriage 315 is speed V / 2, CCD
The original 101 is mechanically moved in a direction perpendicular to the electrical scanning (main scanning) direction, thereby scanning (sub-scanning) the entire surface of the document.

Next, in the printer section, 317 is a yellow image forming section, 318 is a magenta image forming section, 319
Denotes a cyan image forming unit, and 320 denotes a black image forming unit. Since the respective structures are the same, the yellow image forming unit 317 will be described in detail, and the description of the other image forming units will be omitted.

In the yellow image forming section 317, 34
Reference numeral 2 denotes a photosensitive drum, and a vibration type motor (not shown) is installed behind the photosensitive drum 342.
Is driving. The photosensitive drum 342 is an LED array 2
The light from 10 forms a latent image on its surface.

Reference numeral 321 denotes a primary charger, which is a photosensitive drum 342.
Is charged to a predetermined potential to prepare for latent image formation. A developing device 322 develops the latent image on the photosensitive drum 342 to form a toner image. Note that the developing device 322 has a sleeve 3 for applying a developing bias to perform development.
45 are included. A transfer charger 323 discharges from the back of the transfer belt 333 to transfer the toner image on the photosensitive drum 342 to recording paper on the transfer belt 333. In the present embodiment, the transfer efficiency is good, so that the cleaner portion is not provided, but the cleaner portion may be attached.

Next, a procedure for forming an image on a recording paper or the like will be described.

The recording paper and the like stored in the cassettes 340 and 341 are taken out one by one by pickup rollers 338 and 339, and supplied onto the transfer belt 333 by paper feed rollers 336 and 337. The fed recording paper is charged by the adsorption charger 351. Reference numeral 352 denotes a transfer belt roller that drives the transfer belt 333 and
1 to charge the recording paper and the like, and transfer belt 333
To adsorb recording paper. A paper edge sensor 353 detects the edge of a recording sheet or the like on the transfer belt 333. In addition,
The detection signal from the paper edge sensor 353 is
Is sent to the reader unit 402 to be used as a sub-scanning synchronization signal when a video signal is sent from the reader unit 402 to the printer unit 401.

Thereafter, the recording paper or the like is conveyed by the transfer belt 333, and is transferred to the image forming units 317 to 320 in the Y direction.
A toner image is formed on the surface in the order of MCK. The recording paper or the like that has passed through the black image forming unit 320 is easily discharged from the transfer belt 333.
After the charge is removed in step 9, the sheet is separated from the transfer belt 333.
The separated recording paper or the like is discharged onto a paper discharge tray 335 after the toner image is thermally fixed by the fixing device 334.

Next, control of the vibration type motor for driving the photosensitive drums 342 to 345 will be briefly described.

The structure of the vibration type motor is disclosed in
Since it is publicly known from JP-A-3-73887, its description is omitted, but there are various methods for controlling the speed of the vibration type motor.

For example, there is a method in which the frequency of an applied AC wave is resonance-followed to keep the vibrator in a resonance state, and the amplitude of the voltage of the applied AC wave is controlled based on speed information of the vibration type motor detected by the speed detecting means. There is a method of fixing one of the amplitude and the frequency of the voltage of the applied AC wave and controlling the other based on the speed information.

FIG. 6 is a block diagram showing the configuration of a general drive control device for a vibration type motor.

In the figure, thick lines represent a plurality of bus lines. Reference numeral 105 denotes a CPU serving as a processing circuit, which determines a driving frequency and a pulse width of the vibration motor based on speed information of the vibration motor.

Reference numeral 100 denotes a driving circuit.
Is an oscillator such as a crystal oscillator, for example, which oscillates at a frequency of about 20 to 40 MHz and generates a reference clock for generating a drive frequency and a pulse width.
A frequency dividing circuit 903 divides the frequency of a reference clock generated by the oscillator 902 at a frequency dividing rate based on information from the CPU 105. 904 is a pulse width generator, CP
The pulse dividing circuit 90 has a pulse width commanded by U105,
2 and a pulse signal whose phase is shifted by 90 degrees with respect to the pulse signal.

FIG. 7 is a time chart showing two-phase pulse signals (pulse A and pulse B) generated by the pulse width generator 904. The period T in FIG.
3 and the pulse width D is set by the pulse width generator 904.

Returning to FIG. 6, reference numerals 905a and 905b denote boosters. The pulses A and B shown in FIG. 7 are input to each booster, boosted, and supplied to the vibration motor 102.
Thus, the vibration type motor 102 is rotated. 103
Reference numeral denotes a rotation number detector, which detects the rotation state of the vibration type motor 102 as a pulse signal, measures the time of one cycle of a pulse signal having a frequency corresponding to the rotation speed, and feeds back the speed to the CPU 105 as speed data. Then, based on the difference between the target speed and the actual speed, the frequency dividing circuit 903
To determine the frequency division ratio. Thus, the vibration type motor 102 is feedback-controlled so as to always maintain the rotation at the target speed.

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

As shown in FIG. 1, four photosensitive drums 34
2 to 345, respectively.
The driving circuits 110y, 101m, 101c, and 1 are independently provided to the driving device 110 for 102m, 102c, and 102k.
01k is provided. Hereinafter, one of them, the driving circuit 101y, will be described as an example.

The drive circuit 101y drives the vibration type motor 102y according to an ON / OFF signal sent from the CPU 120. That is, the high level of the ON / OFF signal is sent from the CPU 120, and the
1y starts the operation and rotates the vibration type motor 102y. Thereafter, the low level of the ON / OFF signal is
When sent from 0, the drive circuit 101y stops operating,
The vibration type motor 102y stops rotating.

The rotational speed detector 103y is a vibration type motor 10
The rotation speed of 2y is detected, and a signal is output to the comparator 104y. The comparator 104y compares the drive signal serving as a reference (target) with the signal input from the rotation speed detector 103y to perform feedback control to the drive circuit 101y.

When the CPU 120 sends the high level of the ON / OFF signal to each of the driving circuits 101y, 101m, 101c, and 101k at the time of starting the apparatus, as shown in FIG. 5, the CPU 120 sequentially shifts by a predetermined timing as shown in FIG. Send high levels. Thereby, the driving circuit 101
Small inrush currents are respectively generated by the rising edges of y, 101m, 101c, and 101k. However, since the generation timings are shifted, the inrush currents are not multiplied, and the generation of a large inrush current can be suppressed. it can. FIG. 5 is a diagram showing a current at the time of sequentially starting the vibration type motor.

Therefore, as shown in FIG.
107 provided between the motor 6 and the driving device 110
Can be set small. FIG.
Power supply 106 that supplies current to drive device 110 shown in FIG.
FIG.

That is, for example, in the simultaneous driving shown in FIG. 4, it was necessary to set the fuse blowing current value to about 7 A. However, the sequential driving shown in FIG. Can be about 3A. As a result, the vibration type motors 102y to 102y
When an abnormality occurs in any one of k and an overcurrent flows, the fuse is blown quickly and reliably, and therefore, it is possible to prevent a problem from occurring in the device. In other words, the rush current value when each of the vibration-type motors starts driving is lower than the detection level (the fusing current value) of the overcurrent flowing when one of the vibration-type motors becomes abnormal during steady-state driving. As described above, the drive timing interval between the respective vibration type motors is set, and thereby, the above-described problem can be prevented.

The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), or a device including one device (for example, a copier, Facsimile machine, etc.).

Further, the vibration motor drive control device in the above-described embodiment may be constituted by hardware or software. When the function of the vibration motor drive control device is realized by software, A storage medium storing a program code of software for realizing the function of the embodiment described above is supplied to a system or an apparatus, and a computer (or CPU or MPU) of the system or the apparatus reads out the program code stored in the storage medium and reads the program code. It goes without saying that the present invention is also achieved by executing the present invention.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, 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 disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS or the like running on the computer is actually executed based on the instructions of the program code. It is needless to say that the present invention also includes the case where the functions of the above-described embodiments are realized by performing a part or all of the processing described above.

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

[0045]

As described above in detail, according to the present invention, in a drive control device for a plurality of vibration type motors for driving a plurality of movable bodies, respectively, when a command for simultaneously activating a plurality of movable bodies is received, The driving of each of the plurality of vibration motors is sequentially started at predetermined time intervals.

Thus, when the plurality of movable bodies are activated, the respective vibration type motors for driving the respective movable bodies start up separately, so that a large inrush current of the vibration type motor can be suppressed.

Further, the breaking current value of the overcurrent prevention means (fuse) provided between the power supply and the drive control device can be set small, so that when an abnormality occurs in one of the vibration type motors and the overcurrent flows, In addition, the overcurrent prevention means works quickly and reliably without causing trouble in the device, and the power supply current is cut off.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a power supply for supplying a current to the driving device shown in FIG.

FIG. 3 is an internal configuration diagram showing the configuration of a four-drum type color copying machine.

FIG. 4 is a diagram illustrating an inrush current when four photosensitive drums are simultaneously driven.

FIG. 5 is a diagram showing a current at the time of sequentially starting a vibration type motor.

FIG. 6 is a block diagram showing a configuration of a general drive control device of a vibration type motor.

FIG. 7 is a time chart showing two-phase pulse signals (pulse A and pulse B) generated by the pulse width generator.

[Explanation of symbols]

101y, 101m, 101c, 101k Drive circuit 102y, 102m, 102c, 102k Vibration type motor 103y, 103m, 103c, 103k Rotation speed detector, 104y, 104m, 104c, 104k Comparator 106 Power supply 107 Fuse 110 Drive device 120 CPU ( Receiving means, drive start control means)

Claims (9)

[Claims] 1. A drive control device for a plurality of vibration-type motors for driving a plurality of movable bodies, respectively, a receiving unit receiving a command to simultaneously activate the plurality of movable bodies, and a receiving unit receiving the command. And a drive start control means for sequentially starting the drive of each of the plurality of vibration type motors at a predetermined time interval. 2. A drive control unit for individually controlling the driving of the plurality of vibration type motors; a rotation speed detection unit for detecting each rotation speed of the plurality of vibration type motors; and each detection by the rotation speed detection unit. A difference detection unit that detects each difference between the value and each target rotation speed of the plurality of vibration motors; and a feedback unit that feeds back each difference detected by the difference detection unit to the drive control unit. 2. The vibration type motor drive control according to claim 1, wherein said drive start control means controls each operation start of said drive control means, said rotation speed detection means, said difference detection means, and said feedback means. apparatus. 3. The vibration type motor drive control device according to claim 1, wherein the plurality of movable members are four photosensitive drums constituting an image forming apparatus. 4. When a current amount between the drive control device and a power supply is larger than a current amount supplied from the power supply when all of the plurality of vibration type motors operate steadily, a cutoff occurs. 4. An overcurrent protection means which does not perform the operation and interrupts an amount of current supplied from the power supply when an abnormality occurs in one of the plurality of vibration type motors. The vibration type motor drive control device according to any one of the above. 5. A drive control method applied to a drive control device for a plurality of vibration-type motors for driving a plurality of movable bodies, respectively, a receiving step of receiving a command for simultaneously activating the plurality of movable bodies; A drive start control step of, when received, sequentially starting each of the plurality of vibration-type motors at a predetermined time interval. 6. The drive control method according to claim 5, wherein said plurality of movable bodies are four photosensitive drums constituting an image forming apparatus. 7. A computer-readable storage medium storing, as a program, a drive control method applied to a drive control device for a plurality of vibration motors that respectively drive a plurality of movable bodies, wherein the drive control method comprises: A receiving step of receiving a command for simultaneously activating the plurality of movable bodies; and a drive for sequentially starting the drive with a predetermined time interval for each of the plurality of vibration-type motors when receiving the command. And a start control step. 8. The storage medium according to claim 7, wherein said plurality of movable bodies are four photosensitive drums constituting an image forming apparatus. 9. A vibration-type motor for applying a frequency signal to an electro-mechanical energy conversion element disposed on an elastic body to obtain a driving force, and activating the plurality of vibration-type motors simultaneously. In the drive control device for a motor, when starting the plurality of vibration type motors, the drive control unit starts driving each vibration type motor at a predetermined time interval, and the predetermined time interval is: The inrush current value generated when the respective vibration type motors are sequentially started by the drive control means,
A vibration-type motor drive control device, wherein a value is set so as not to exceed a fusing current value that flows when one vibration-type motor enters an abnormal state and shuts off power.