JPH11178370A - Vibration-type drive device and image-forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the wasteful wear in the frictional pretrial of a sliding part, and to attain long life by stopping a control means for driving, based on the speed detection information of a vibration-type actuator via phased deceleration within the allowable driving range of emergency stop in accordance with to the input of an emergency stop command. SOLUTION: Two drive circuits are used for driving a single vibration actuator 25, and each of pulses with phases of 0, 180, 90, and 270 degrees is added to primary-side MOSFETs 19-22 of transformers 23 and 24. A pulse with a phase difference of 90 degrees is outputted from a pulse formation circuit 7 to each of the two circuits. Based on speed information from a speed detection means 26 of an actuator (a body to be driven), the pulse control circuit 7 is controlled so as to reach the value of a speed command (target speed) by a speed control circuit 8. At emergency stop, a pulse width is changed so that the stop is made through the change in a plurality of pulse widths until the stop, thus reducing the speed difference between the actuators at stop action and the stresses given among the actuators and equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus including at least one of a vibration type driving device, a printing device, an image capturing device, and an image processing device.

[0002]

2. Description of the Related Art In general, a vibration type actuator has a piezoelectric element disposed at a position spatially having a phase difference of 90 ° with respect to an elastic body such as a metal, and these piezoelectric elements have a phase difference of 90 ° with each other. By applying a two-phase alternating signal having the following, a traveling wave is generated on the elastic body, and the elastic body and a contact body that comes into pressure contact with the elastic body via a pressurizing unit by frictional force. It is made to move relatively, and as the elastic body, there is a shape such as a ring shape, a rod shape,
When the vibrator is made of an elastic body and a piezoelectric element, and the vibrator is fixed, the contact body functions as a moving body.

[0003] A friction material for obtaining an appropriate frictional force is adhered, applied or formed on a contact portion between the vibrating body and the contact body.

[0004] The characteristics of such a vibration type actuator are that, compared to an actuator using electromagnetic force, the driving torque at low speed is large, the response is good, and human beings use vibrations beyond the audible range. The point that it is quiet because there is no driving noise is raised.

For this reason, a vibration type actuator is used as a drive source of a photosensitive drum as an image carrier of an image forming apparatus such as an electrophotographic copying machine, and a transfer material for transferring a transfer material such as transfer paper to a transfer position with the photosensitive drum. It has been proposed to use it as a drive source for a transport means.

Incidentally, since an image forming apparatus generally has a driving section and a high voltage section, the image forming apparatus has a housing which is isolated from the outside so that a user cannot touch these sections during driving.

[0007] When the user operates these devices for handling a paper jam or the like, the user opens the door provided on the housing. At this time, as disclosed in Japanese Patent Application Laid-Open No. 9-106126, a sensor for detecting opening / closing is provided on the door, and when it is detected that the door is opened, the power supply for power supply is shut off to drive the driving unit. It stops so that no voltage is generated in the high voltage section.

[0008]

In such an image forming apparatus, when an actuator (electromagnetic motor) using electromagnetic force is used as a drive source,
Even if a stop command is issued in response to the detection of the opening of the door, since the electromagnetic motor does not use frictional force as a driving principle, wear due to sudden stop does not substantially affect the life.

However, in such an image forming apparatus, when a vibration type actuator is used as a drive source, when a stop command is issued in response to the detection of the opening of the door, the power supply for power supply is cut off simultaneously with the detection of the opening of the door. Therefore, power is not supplied to the drive circuit of the vibration type actuator, and the vibration type actuator is suddenly stopped from the steady driving speed.

On the other hand, a vibration-type actuator transmits a driving force between a moving body and a vibration body via a frictional material. Therefore, unlike a conventional actuator using an electromagnetic force, the frictional material is rapidly stopped. May be stressed to shorten the life of the actuator. In other words, there is a problem that the sudden stop greatly affects the life.

In an apparatus using a plurality of actuators for the same drive system (for example, as shown in FIG. 4 where a plurality of image transfer apparatuses are arranged in parallel in the paper traveling direction), when each actuator is stopped, If there are variations in the constants, for example, when power supply to the drive circuit is cut off or each actuator stops suddenly, the time to stop differs, resulting in stress on other actuators or the transport system. There was a fear of giving.

An object of a first invention according to the present application is to reduce useless wear of a friction material in a sliding portion in response to a sudden stop command to a vibration type actuator without affecting the state of the sudden stop. Another object of the present invention is to provide a vibration-type driving device that can achieve a long life.

An object of a second invention according to the present application is to provide a vibration-type driving device in which stop timings of all vibration-type actuators are not shifted in response to a sudden stop command to a plurality of vibration-type actuators. What you want to do.

An object of a third invention according to the present application is to provide a vibration type actuator as a driving source, in response to a command for a sudden stop, without wasting the frictional material in the sliding portion without affecting the state of the sudden stop. It is an object of the present invention to provide an image forming apparatus that can reduce wear and extend the life.

An object of a fourth invention according to the present application is to provide an image forming apparatus in which, in response to a command for abrupt stop to a plurality of vibrating actuators as a driving source, all the vibrating actuators are not shifted in stop timing. It is intended to provide a device.

[0016]

SUMMARY OF THE INVENTION A vibration type driving apparatus for realizing the object of the first invention according to the present invention comprises a vibration type actuator and a driving means for outputting an alternating signal having a different phase to the vibration type actuator. And speed control means for detecting the speed of the vibration-type actuator, and control means for controlling the drive means based on the detection information of the speed detection means, wherein the control means ,
The vibration-type actuator is stopped after stepwise deceleration within a driving range in which sudden stop is allowed.

The configuration of the vibration type driving apparatus for realizing the object of the second invention according to the present application includes a plurality of vibration type actuators, a driving means for outputting alternating signals having different phases to the vibration type actuators, Speed detecting means for detecting the speed of the vibration-type actuator, and control means for controlling the plurality of driving means based on each detection information of the plurality of speed detecting means. With this input, the plurality of vibration-type actuators are stopped through a stepwise deceleration while being synchronized within a drive range in which sudden stop is allowed.

Further, when the sudden stop command is provided in a housing having a door together with a high voltage section and a drive section,
The output is a door sensor that detects the opening of the door.

In such a case, the control means sets the vibration type actuator within a predetermined time from when the door open detection output of the door sensor is input to when the drive unit or the high voltage unit becomes accessible. The driving power of the device is turned off when the driving speed becomes lower than the predetermined value.

An image forming apparatus for realizing the object of the third invention according to the present application is provided with the vibration type driving device having the above-described configuration, and drives the image carrier by the vibration type actuator. .

A first configuration of an image forming apparatus for realizing the object of the fourth invention according to the present application is provided with a vibration type driving device having the above-described configuration, and a plurality of image carriers are respectively controlled by the vibration type actuator. It is designed to be driven.

A second configuration of the image forming apparatus for realizing the object of the fourth invention according to the present application is provided with the vibration type driving device having the above configuration, and drives the transfer material conveying means by the vibration type actuator. In addition, a plurality of image carriers that are arranged in parallel in the transport direction of the transfer material transport unit are each driven by the vibration type actuator.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a flowchart showing the operation of a first embodiment of the present invention, FIG. 2 is a sectional view of a vibration type actuator according to the present embodiment, and FIG. FIG. 4 is a schematic cross-sectional view of a driving circuit of the vibration type actuator of FIG. 2, and FIG. 4 is a schematic sectional view of an image forming apparatus equipped with a vibration type driving device including the vibration type actuator, its driving circuit and a driven body.

In FIG. 2, the vibration type actuator is
A piezoelectric element 4 as an electro-mechanical energy conversion element is bonded to the ring-shaped elastic body 3 at a position having a phase difference of 90 ° from each other spatially, and a piezoelectric element (having a position shift of an odd multiple of half a wavelength) The two-phase alternating signal having a phase difference of 90 ° is applied to the A-phase drive unit and the B-phase drive unit 4). It is generating waves.

Further, the rotor 1 as a moving body is pressed against the driving portion of the elastic body 3 by the spring force of the spring member 2 also serving as a transmission member, so that the elastic body 3 is moved by the traveling wave.
, The rotor 1 is driven by friction. A friction member 5 having a predetermined friction coefficient different from that of the base material is provided at a contact portion between the vibrator and the rotor.

Reference numeral 6 denotes an output shaft which is fixed to a spring member 2 integral with the rotor 1 so that the rotational force of the rotor 1 can be taken out. A is a base member that also serves as one of the motor cases. The ring-shaped elastic body 3 is fixed by screws, and a bearing that rotatably supports the output shaft 6 is mounted. B is a case member that constitutes the other of the motor case, and is attached to the base member A with screws.

FIG. 3 shows a driving circuit for driving the vibration type actuator. Since the driving of the vibration type actuator requires a voltage of several hundred volts, a transformer 23 for A-phase driving and a B-phase driving DC power supply circuit 27 is connected to each center tap on the primary side of transformer 24 for power supply, and MOSFETs are connected to both ends on the primary side of transformers 23 and 24.
19, 20, 21 and 22 are connected, and a booster circuit for obtaining a high voltage by switching is used. Transformer 2 when driving
MOSFET 19 connected to both ends of the primary side of 3, 24
And 20 gates are connected by 180 ° phase shifter 9 and M
A 180 ° phase shifter 1 is connected to the gates of OSFETs 21 and 22.
With 0, a pulse having an arbitrary pulse width and frequency having a phase difference of 180 ° from each other is added. In order to drive one vibration type actuator, two drive circuits as shown in FIG. 3 are used, and the phases of the pulses applied to the gates of the MOSFETs 19, 20, 21, 22 are 0 ° and 180 °, respectively. °, 9
It is driven to be 0 ° and 270 °. Pulses having a phase difference of 90 ° are output from the two circuits for driving and the pulse shaping circuit 7 to these two circuits.

Reference numeral 7 denotes a speed control circuit, which is a pulse shaping circuit for obtaining a speed command (target speed) value based on speed information from speed detecting means 26 for detecting the speed of the vibration type actuator (or driven body). 7 is controlled.

In the circuit shown in FIG.
By changing the pulse width of the pulse applied to the gates 9 to 22, the amount of current flowing into the transformer can be adjusted as shown in FIG. 5, so that the voltage output to the secondary side of the transformer can be changed.

Since the driving speed of the vibration type actuator and the applied voltage have a relationship as shown in FIG. 6, the speed can be finally changed by the pulse width.

FIG. 4 shows a color image forming apparatus using such a vibration type actuator as a drive source. The vibration type actuator is an image forming process unit 3 for each color.
The photosensitive drums 342 to 345 serving as image carriers of 17, 318, 318 and 320 are used for driving a driving roller 348 for driving a transfer material conveying belt 333.

The image forming process units are arranged in parallel along the transfer material transfer direction, that is, along the transfer material transfer direction of the transfer material transfer belt 333, and transfer the cyan, magenta, yellow, and black images, respectively. Do.

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

In FIG. 4, reference numeral 101 denotes a CCD, 311 denotes a substrate on which the CCD 101 is mounted, 312 denotes a printer processing unit, 301 denotes a platen glass (platen), and 302 denotes a document feeder (DF). There is also a configuration in which a mirror pressure plate (not shown) is mounted instead of the paper device 302), 30
3 and 304 are light sources (halogen lamps or fluorescent lamps) 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,
Reference numeral 310 denotes a lens for condensing reflected light or projection light from the original on the CCD 101, and 314 denotes a halogen lamp 303.3.
Reference numeral 315 denotes a carriage that houses the mirrors 308 and 309, and 313 denotes an interface (I / F) unit with another CPU or the like. Note that the carriage 314 has a speed V and the carriage 315 has a speed V / 2.
The entire surface of the document is scanned (sub-scanning) by mechanically moving in the direction perpendicular to the electrical scanning (main scanning) direction of
I do.

Next, the configuration of the printer unit will be described. 4, an M (magenta) image forming unit 317, a C (cyan) image forming unit 318, a Y (yellow) image forming unit 319, and K as image forming process units
(Black) Since the configuration of the image forming unit 320 is the same, the M image forming unit 317 will be described in detail, 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. A developing device 322 develops the latent image on the photosensitive drum 342 to form a toner image. Note that the developing device 322 includes a sleeve 345 for applying a developing bias to perform development. A transfer charger 323 discharges the toner image on the photosensitive drum 342 from the back surface of the transfer material transport belt 333 to transfer the toner image on the photosensitive drum 342 to the transfer material transport belt 3.
The image is transferred to a recording paper on the recording medium 33. In the present embodiment, since the transfer efficiency is good, no cleaner section is provided. Needless to say, there is no problem even if the cleaner is mounted.

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 and 341 are picked up by pickup rollers 339 and 338.
The transfer material transport belt 33 is fed by the sheet feed rollers 336 and 337 for each sheet.
3 is supplied. The fed recording paper is supplied to the adsorption charger 3
Charged at 46. 348 is a transfer belt roller,
The transfer material transport belt 333 is driven, and the attraction charger 3
The recording paper and the like are charged in pairs with the recording material and the recording paper and the like are attracted to the transfer material transport belt 333.

A paper edge sensor 347 detects the edge of a recording sheet or the like 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 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 recording paper or the like is separated from the transfer material transport belt 333. The separated recording paper and the like are charged by pre-fixing chargers 351 and 352 in order to compensate for the toner attraction force and prevent image disturbance, and then the fixing device 334.
After the toner image is heat-fixed at, the paper is discharged to a paper discharge tray at 335.

The photosensitive drums 342 to 345 of the image transfer apparatus according to the present embodiment are directly connected to a rotary shaft which is an output shaft of a rotary vibration type actuator as shown in FIG. By 4
The transfer portions (outer circumferences) of the two photosensitive drums are driven at the same rotational speed (peripheral speed). Also, a vibration type actuator is used for driving a driving roller 348 for driving the transfer material conveying belt 333, and is driven in synchronization with the above four transfer portions.

In such an image forming apparatus, the apparatus has the above-described driving portion, the transfer device, and the high-voltage portion for driving the vibration type actuator. Therefore, during normal use, a housing is provided to cover these parts so that a general user does not touch these parts during driving. An operation door for operating the inside of the device when a user performs processing such as paper jam, replacement of toner or a print cartridge, or the like is installed in the housing. An open / close sensor is attached to this operation door. An opening / closing hook is attached to the opening / closing door, and the opening / closing sensor is linked to the hook.

Since the operator opens the door after pulling the hook, there is a time lag of several seconds from when the sensor detects that the door is opened to when the operator can operate the internal device. During this time, the control unit of the image forming apparatus performs the operation shown in FIG. 1 to complete the operation of stopping the actuator.

That is, when the control unit detects that the door is about to be opened by the open / close sensor (# 1), the pulse widths of the drive pulses of the five actuators are simultaneously changed to a predetermined value smaller than that in the steady drive (# 1). 2). Thereafter, the pulse width is reduced at predetermined time intervals so that the pulse width finally becomes 0 or lower than a predetermined speed (# 3). Then, the power supply for supplying power to the actuator is cut off (#
4).

The width and interval at which the operation of the pulse is performed may use predetermined values, or may be adjusted so that the speed detected by the speed detecting unit falls within a predetermined range.

In the present embodiment, as shown in FIG.
The pulse width is reduced by a predetermined time T1 from the state (a) showing the pulse width giving the speed during the image forming process. (B) shows this state, in two stages (for two pulses).
The pulse width has been reduced. If the speed does not become lower than the predetermined value even in this state, the pulse width is further reduced by the predetermined time T2. (C) shows this state.
The pulse width is reduced in stages (for two pulses). If the speed still does not fall below the predetermined value in this state, the pulse width is reduced by the predetermined time T3. (D) shows this state. Similarly, the pulse width is reduced by two stages (two pulses). Then, the pulse width is sequentially reduced so as to be equal to or lower than a predetermined speed.

Here, when stopping from the state shown in FIG. 12A as a normal stop method, if an operation of reducing the pulse width by one pulse is performed, it is not possible to make an emergency stop.
However, if the pulse width that is reduced at a time is increased, a sudden stop may be caused. Therefore, the pulse width during the emergency stop operation is determined to a value at which the speed of the actuator does not suddenly become zero. That is, at the time of an emergency stop, the pulse width is changed so as to stop after a plurality of pulse width changes until the stop.

Since these operations are performed simultaneously for all the actuators driven in synchronization, the speed difference between the actuators is reduced even during the stop operation, and the stress applied to each other and the equipment is reduced. can do.

The time for completing these operations is set to a value sufficiently smaller than the time when the operator is expected to be able to touch the device after the opening / closing sensor detects the operation of the door.

Further, as shown in FIG. 1, in the above embodiment, the power supply for power supply is cut off when the pulse width becomes 0. In general, however, the drive circuit of the vibration type actuator is stabilized with respect to the power supply. Has a capacitive element to measure
When the power is turned off, the voltage decreases with a time constant as shown in FIG. 7.
Alternatively, the actuator speed can be changed by the pulse width even if the power is turned off at an appropriate time during the reduction of the pulse width.

Therefore, even in this case, an operation for preventing the actuator from suddenly stopping can be performed as in the above embodiment.

(Second Embodiment) FIG. 8 is a flowchart showing the operation of the second embodiment.

The drive frequency and the speed of the vibration type actuator as shown in FIG. 2 have a relationship as shown in FIG. 9 and a gentle curve region on the higher frequency side than the frequency at the peak resonance point is defined as the drive region. Therefore, when the driving circuit as shown in FIG. 3 is used, the speed can be reduced by increasing the frequency of the pulse input to the gate of the MOSFET.

Also in the second embodiment, the vibration type actuator is used for the drive unit of the image forming apparatus similar to the first embodiment. When the control unit of the image forming apparatus detects that the door is about to be opened by the open / close sensor (# 81), 5
The frequencies of the drive pulses of the two actuators are simultaneously changed to a predetermined value higher than that during the steady drive (# 82). Thereafter, the frequency of the pulse is increased at predetermined time intervals until the speeds of all the vibration type actuators become 0 or lower than a predetermined value (# 2, # 3).

Thereafter, the pulse width is set to 0 (# 4), and the power supply for supplying power to the actuator is cut off. The width and interval at which the operation of the frequency of the pulse is performed may use predetermined values, or may be adjusted so that the speed detected by the speed detection unit falls within a predetermined range. The value of the frequency during the operation is adjusted to a value at which the speed of the actuator does not become zero. Since these operations are simultaneously performed on all the actuators driven in synchronization, the speed difference between the actuators can be reduced even during the stop operation, and the stress applied to each other and the equipment can be reduced.

The time for completing these operations is set to a value sufficiently smaller than the time when the operator is expected to be able to touch the device after the opening / closing sensor detects the operation of the door.

Further, as shown in FIG. 8, in the above embodiment, the power supply for power supply is cut off when the operation of the frequency is completed. In general, however, the drive circuit of the vibration actuator stabilizes the power supply. Because the voltage drops with a time constant when the power is turned off as shown in FIG. 7, depending on the configuration, the power may be supplied simultaneously with the detection of the open / close sensor or at an appropriate time during the change of the frequency. It is possible to change the speed of the actuator depending on the frequency even if the frequency is cut off. Therefore, even in this case, the operation for preventing the sudden stop of the actuator can be performed as in the above embodiment.

(Third Embodiment) FIG. 10 is a flowchart showing the operation of the third embodiment. The vibration type actuator as shown in FIG. 2 has a relationship as shown in FIG. 11 between the phase difference between two driving phases (A phase and B phase) and the speed. That is, when two driving circuits as shown in FIG. 3 are used, the speed can be reduced by increasing or decreasing the phase difference of the pulse input to the gate of the MOSFET of each circuit to more than 90 °.

Also in the third embodiment, the vibration type actuator is used for the driving section of the image forming apparatus similar to the first embodiment. When the control unit of the image forming apparatus detects that the opening / closing sensor is about to open the door (# 10)
1) The phase difference between the drive pulses of the five actuators is simultaneously changed to a predetermined value larger than 90 ° (# 102).
In the normal driving, it is assumed that driving is performed with a phase difference of 90 degrees. Thereafter, the phase difference of the pulse width is increased (or decreased) at predetermined time intervals, and when the speeds of all the vibration type actuators become 0 or less than a predetermined value (# 10).
2, # 103) Then, the pulse width is set to 0 and the power supply for supplying power to the actuator is cut off.

The width and interval at which the operation of the pulse phase difference is performed may use predetermined values, or may be adjusted so that the speed detected by the speed detecting unit falls within a predetermined range. The value of the phase difference during the operation is adjusted to a value at which the speed of the actuator does not become zero.

In the above-described embodiment, an example is shown in which the phase difference is increased, but the phase difference may be reduced. Since these operations are simultaneously performed on all the actuators driven in synchronization, the speed difference between the actuators can be reduced even during the stop operation, and the stress applied to each other and the equipment can be reduced.

The time for completing these operations is set to a value sufficiently smaller than the time when the operator is expected to be able to touch the device after the opening / closing sensor detects the operation of the door.

Further, in the third embodiment shown in FIG. 10, the power supply for power supply is cut off when the operation of the phase difference is completed. In order to stabilize, the capacitor has a capacitance element. When the power is turned off, the voltage decreases with a time constant as shown in FIG. 7. Even if the power is turned off at an appropriate time, the speed of the actuator can be changed by the phase difference.

Therefore, even in this case, an operation for preventing sudden stop of the actuator can be performed as in the above embodiment.

[0065]

According to the first to ninth aspects of the present invention, even when the vibration type actuator is suddenly stopped, the vibration type actuator is not stopped immediately but is decelerated and stopped within an allowable range. This has the effect of preventing abrupt wear of the part and prolonging the life of the vibration type actuator.

In a system using a plurality of vibration-type actuators interlocked with each other, there is an effect that stress applied to each other and a device at the time of stoppage is reduced, and their life is extended.

According to the tenth and eleventh aspects of the present invention, the driving of the vibration type actuator is stopped and the power is turned off before the door is opened and the high voltage section or the driving section enters and the power is turned off. Various operations can be performed.

According to the twelfth, thirteenth, and fourteenth aspects of the present invention, even when the door of the image forming apparatus is opened, a high load is applied to the friction sliding portion of the vibration type actuator for driving the image carrier and the transfer material conveying means. Can be prevented from abruptly abrading due to the addition of water, and the life of the vibration type actuator can be extended.

A system using a plurality of vibration-type actuators interlocked with each other has the effect of reducing the stress applied to each other and the equipment at the time of stoppage and prolonging their life.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the operation of a first embodiment of the present invention.

FIG. 2 is a sectional view of a vibration type actuator used in the embodiment of the present invention.

FIG. 3 is a drive circuit diagram of the vibration-type actuator according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram of an image forming apparatus using the vibration type actuator according to the first embodiment.

5 is a diagram showing the relationship between the pulse width of the circuit of FIG. 3 and the current flowing through the primary side of the transformer.

FIG. 6 is a diagram showing a relationship between an applied voltage and a driving speed of a vibration type actuator.

FIG. 7 is a diagram illustrating a state of a voltage change when a power supply power supply of a vibration type actuator drive circuit having a capacitive element is cut off.

FIG. 8 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 9 is a diagram illustrating a relationship between a frequency of a pulse applied to the drive circuit according to the second embodiment and a drive speed;

FIG. 10 is a flowchart showing the operation of the third embodiment of the present invention.

FIG. 11 is a diagram illustrating a relationship between a phase difference between two-phase pulses applied to the drive circuit according to the third embodiment and a drive speed.

FIGS. 12A to 12D are diagrams illustrating a method of reducing a drive pulse during a stop operation according to the first embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2 Spring member 3 Elastic body 4 Piezoelectric element 5 Friction material 6 Output shaft 7 Pulse shaping circuit 8 Speed control circuit 9,10 180 degree phase shift circuit 19-22 MOSFET 23,24 Step-up transformer 25 Vibration type actuator 26 Speed detection Means 27 DC power supply 317 to 320 Image forming unit 342 to 345 Photosensitive drum 333 Transfer material transport belt 348 Drive roller

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinji Yamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (14)

[Claims] 1. A vibration type actuator, a driving unit for outputting an alternating signal having a different phase to the vibration type actuator, a speed detection unit for detecting a speed of the vibration type actuator, and based on detection information of the speed detection unit. Control means for controlling the driving means.The control means stops the vibration-type actuator through a stepwise deceleration within a driving range in which the sudden stop is allowed by inputting a sudden stop command. Characteristic vibration type driving device. 2. A plurality of vibration-type actuators, a driving unit that outputs alternating signals having different phases to the vibration-type actuator, a speed detection unit that detects speeds of the plurality of vibration-type actuators, and the plurality of speed detections Control means for controlling the plurality of drive means based on each detection information of the means, the control means, upon input of a sudden stop command,
A vibration-type driving device, wherein the plurality of vibration-type actuators are stopped through a stepwise deceleration while being synchronized within a drive range in which sudden stop is allowed. 3. The drive unit has a drive circuit unit that varies the speed of the vibration-type actuator according to an applied voltage, and the control unit includes a control unit that gradually reduces the applied voltage in response to a sudden stop command. 2. The method according to claim 1, wherein
Or the vibration type driving device according to 2. 4. The driving unit includes a driving circuit unit that varies the speed of the vibration-type actuator according to a frequency, and the control unit includes a control unit that gradually increases the frequency in response to a sudden stop command. 2. The method according to claim 1, wherein
Or the vibration type driving device according to 2. 5. The control means has a drive circuit section for varying the speed of the vibration-type actuator in accordance with a phase difference between two drive phases, and the control means controls the two-phase drive phase in response to a sudden stop command. 3. The vibration-type driving device according to claim 1, further comprising a control unit configured to make the phase difference larger or smaller than 90 degrees. 6. The vibration-type driving device according to claim 3, wherein the driving circuit changes a voltage applied to the vibration-type actuator by changing an output pulse width of a pulse generation circuit. . 7. The vibration-type driving device according to claim 4, wherein the driving circuit changes a frequency of the vibration-type actuator by changing a frequency of an output pulse of a pulse generation circuit. . 8. The vibration according to claim 5, wherein the drive circuit unit changes a phase difference to the vibration type actuator by changing an output pulse width of a two-phase pulse generation circuit. Mold drive. 9. The vibration type driving device according to claim 6, wherein the control unit reduces the output pulse of the driving circuit unit at a predetermined step interval of at least two pulses. . 10. An output of a door sensor, which is provided in a housing having a door together with a high-voltage section and a driving section, and detects opening of the door, is used as the sudden stop command to the control means. Item 10. The vibration type driving device according to any one of Items 1 to 9. 11. The control means sets a drive speed of the vibration-type actuator within a predetermined time from when a door open detection output of the door sensor is input to when the drive unit or the high-pressure unit becomes accessible. 11. The vibration type driving apparatus according to claim 10, wherein the power supply is turned off when the driving speed becomes lower than a predetermined value so that the power supply of the device including the housing is turned off. 12. An image forming apparatus comprising the vibration type driving device according to claim 10 or 11, wherein the image carrier is driven by the vibration type actuator. 13. An image forming apparatus comprising the vibration type driving device according to claim 10 and driving a plurality of image carriers by the vibration type actuator. 14. A plurality of vibration type driving devices according to claim 10 or 11, wherein a transfer material conveying means is driven by said vibration type actuator and arranged in parallel in a conveying direction of said transfer material conveying means. An image forming apparatus, wherein each of the image carriers is driven by the vibration type actuator.