JP2001037268A - Vibrating wave driving gear, image forming apparatus and apparatus driven by vibrating motor used as driving source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly start or stop a vibrating motor, when a photoreceptor drum driven by the oscillating wave motor is driven synchronously with the rotation of a polygon mirror. SOLUTION: For a stationary state in which drive control is performed so as to cause an encoder pulse of a vibrating motor 3 to have a specified phase difference from a BD signal generated by the rotation of a polygon mirror, false timing pulses having a period approximately the same as or different from that of BD signals are generated, and drive of the vibrating motor is controlled by these false timing pulses when the motor 3 is started or stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration wave drive in which a plurality of driving means including a vibration wave device cooperate with each other, and drives and controls the vibration wave device in synchronization with one of the driving means in a cooperative relationship. The present invention relates to an apparatus and an image forming apparatus.

[0002]

2. Description of the Related Art In recent years, a vibration wave device such as a vibration wave motor or the like, which generates a vibration wave on a vibrating body by a piezoelectric element as an electro-mechanical energy conversion element and gives a driving force to a moving body by the vibration energy. There has been proposed a control device for controlling the vibration wave device, which is applied to a driving source of a focal length adjusting mechanism of an autofocus lens, a positioning actuator of a semiconductor manufacturing apparatus, and the like.

Further, as an example of the configuration of an image forming apparatus, the image forming apparatus has an exposure unit that converts an image signal into a light signal, scans and exposes the photosensitive drum, forms an electrostatic latent image on the photosensitive drum, and forms the electrostatic latent image on the photosensitive drum. An electrophotographic image forming method in which a latent image is developed by a developing device, a visible toner image is formed on a photosensitive drum, then transferred onto a sheet, and the toner image is fixed on the sheet by a fixing device such as a fixing roller. Although a device has been proposed,
Driving sources such as a DC brushless motor and a stepping motor have been used for driving the photosensitive drum.

[0004] In the case of a DC brushless motor, it is general that the motor is driven at high speed and decelerated by a gear or a timing belt. In driving the photosensitive drum, unevenness in rotation due to uneven driving (wow and flutter) generated at a constant period of the motor, vibration in the deceleration means, meshing of gears, etc. affects the image quality. The unevenness in the rotational speed of the photosensitive drum due to the drive unevenness causes the line intervals in the sub-scanning direction to be non-uniform when raster-scanning the photosensitive drum to form an image.

[0005] In particular, in a color image forming apparatus for superimposing multi-color images, not only realization of uniformity of image recording of each color but also accurate registration of images of each color can be achieved, and reproduced images of high image quality can be obtained. It is important to get. That is, in image formation,
When density unevenness or image expansion and contraction occurs, even if the image quality is deteriorated at a level that is not conspicuous in a single-color image, when a plurality of colors are superimposed, an unsightly image such as color unevenness or moiré is generated. For example, 60 DPI (dot per i
In the nch) raster line, unevenness in line intervals every 42.3 μm is detected as density unevenness by human eyes, and is perceived as color shift, color unevenness, and density unevenness in the case of a color image. Further, in the driving means of the intermediate recording medium or the recording medium carrier, the unevenness in driving also causes the line intervals in the sub-scanning direction to be non-uniform, or causes registration deviation of each color.

In particular, it is often not easy to remove vibrations caused by the deceleration means and rotational unevenness of gears or the like in a meshing cycle, and various driving modes have been proposed. For example, a direct drive system has been proposed in which a motor drive shaft is directly connected to a photosensitive drum without using a deceleration unit. Such a direct drive can significantly reduce the rotation unevenness in the mechanical drive transmission means, and can significantly reduce the rotation unevenness in the mechanical drive transmission means. This is effective in reducing rotation unevenness caused by the above.

However, in general, when the DC brushless motor is operated at a low speed, the drive unevenness is worse than at a high speed. In recent years, increasing the speed of an image forming apparatus has been studied, but the process speed is 100 to 250 mm / S.
Assuming that the process speed is 250 mm / S and the diameter of the photosensitive drum is 60 mm, the motor rotation speed when directly driving the photosensitive drum recording medium carrier is 79.6 r.
pm and low-speed driving are required. Furthermore, when various materials such as cardboard and OHP are used for the printing paper, image formation is performed at a speed reduced to about 1/2 to 1/4 of a normal process speed in order to prevent deterioration of image quality in a fixing process. It is possible. In such a case, the rotation speed of the photosensitive drum also needs to be reduced to 1/2 to 1/4, and the motor rotation speed is 39.8 to 19.9 rpm. At such a low speed, when the photosensitive drum is directly driven by the DC motor, the rotation unevenness is not negligible,
The reproduced image causes a remarkable deterioration of image quality.

Conventionally, a D (Digital Phase Locked Loop) control system which detects the number of rotations and performs PLL (phase lock loop) control using a magnet magnetized on a rotor of a drive motor of a photosensitive drum or a recording material holding means.
C motor control is being performed. In general, the rotation speed used in a DC brushless motor is from 1,000 to 2,000 rpm, but it is difficult to realize sufficiently small drive unevenness when driving at an extremely low speed of 39.8 to 19.9 rpm. .

Various proposals have also been made regarding the use of a stepping motor for driving the photosensitive drum. As in the case of the DC brushless motor, a type in which the photosensitive drum is driven by using a deceleration unit, or a type in which the photosensitive drum is directly driven are used. In particular, in the case of a stepping motor, it is relatively easy to change the rotation speed to low-speed driving,
Usually, this is realized by setting the phase signal to be driven to a low frequency. However, at the time of low-speed driving such as used in direct driving or the like, vibration at the step angle increases, and rotation unevenness increases. Therefore, especially at the time of low-speed driving, image unevenness has occurred. For such low-speed driving, a driving current control method such as a micro-step driving method has been proposed, but a sufficient effect has not been obtained.

The scanning exposure means converts an image signal into a pulse width modulation signal of laser light, rotates a polygon mirror, and scans the photosensitive drum with laser light to form a latent image. A device has been proposed. Such a laser scanning type image forming apparatus has a beam detecting unit (hereinafter, referred to as a BD detecting unit) for detecting a laser beam to be scanned outside the image area of the photosensitive drum, and performs detection from the BD detecting unit. In synchronization with the signal (BD signal), the laser light is modulated into a laser beam corresponding to the image signal to form a latent image. If the paper transport direction is the sub-scanning direction,
By scanning the laser beam in a direction substantially perpendicular to the sub-scanning direction (referred to as a main scanning direction), a latent image is sequentially formed in units of one line. In a laser scanning type image forming apparatus, the line pitch in the sub-scanning direction becomes non-uniform due to uneven rotation of the photosensitive drum, resulting in an unsightly image such as uneven pitch. In an apparatus for forming a color image by forming toner images of respective colors and superimposing them sequentially, slight rotation unevenness of the photosensitive drum causes significant color unevenness.

Many proposals have been made for a method of controlling a vibration wave device such as a vibration wave motor, and a typical method is to apply a method to a piezoelectric element as an electro-mechanical energy conversion element of a vibration wave device. There is a method of controlling the operation speed by changing the frequency and amplitude of a voltage signal (drive signal).

Here, the relationship between the frequency and amplitude of the drive signal and the operation (rotation) speed is as shown in FIG. In other words, the rotational speed has a characteristic that the resonance frequency of the vibrating body has a peak, gradually decreases toward the high frequency side, and sharply decreases toward the low frequency side. In addition, the rotation speed has a characteristic that the rotation speed increases as the amplitude of the drive signal increases.

In the case of controlling the speed by changing the frequency (hereinafter referred to as frequency speed control), a VCO capable of obtaining a relatively fine frequency resolution with respect to the input piezoelectric material.
(Voltage-controlled oscillator) is often used. However, in terms of cost, it is preferable to use a digital circuit (gate array) without using an analog circuit such as a VCO. However, when a gate array is used, the frequency of the drive signal is determined by the frequency of the clock signal, and the clock frequency is limited, so that the frequency resolution cannot be increased as much as the VCO. However, there is a disadvantage that speed unevenness is likely to increase.

On the other hand, when the speed is controlled by changing the amplitude (hereinafter, referred to as amplitude speed control), it is possible to perform control with less speed unevenness as compared with frequency speed control using a digital circuit. However, in order to perform accurate speed control by the amplitude speed control, the drive frequency must always be set to a frequency higher than the resonance frequency and close to the resonance frequency. There is a drawback that accurate speed control is difficult because it fluctuates due to changes.

Therefore, for example, (1) JP-A-3-239
Japanese Patent Application Laid-Open Publication No. 168/168 and Japanese Unexamined Patent Application Publication No. 4-222476 disclose a method of detecting a vibration frequency of a vibration wave device such as a vibration wave motor and controlling the frequency of a drive signal to be always near a resonance frequency. A control method has been proposed in which the amplitude of the drive signal is changed so as to reduce the difference from the target speed while detecting the actual operation speed.

(2) Japanese Patent Application Laid-Open No. 6-237584 discloses a control method in which only the frequency is changed at the time of starting to bring the operating speed close to the target speed, and thereafter the operating speed is controlled by controlling only the amplitude of the drive signal. Has been proposed. According to these conventional control methods, it is possible to perform control with less speed unevenness in the digital circuit.

By the way, a vibration wave motor is used for applications in which a plurality of motors continue to operate for a long time with high rotational accuracy based on a series of operation sequences, such as an electrophotographic image forming apparatus. There was no example in which such a vibration wave device was used. Among image forming apparatuses, in a color image forming apparatus that needs to superimpose a plurality of color toner images sequentially and very accurately, a photosensitive drum as an image carrier for carrying color toner, and a plurality of photosensitive drums are used. In particular, there is a need for a motor that has extremely small rotation unevenness of a transfer material transport belt as a transfer material transport means for transporting the transfer material to a transfer position of the transfer position, and that eliminates image position deviation.

For such applications, it is very effective to apply an inexpensive, small-sized vibration wave device having extremely small rotational speed unevenness, and the present applicant has studied its practical use.

[0019]

However, in a conventional vibration wave device, which is a device using a vibration wave device such as a vibration wave motor as a driving source, there is a problem in that the speed and position accuracy as a single motor or actuator are not sufficient. In many cases, speed fluctuation among a plurality of vibration wave devices such as a vibration wave motor did not cause a problem, and there was almost no application example of driving for a long time.

Therefore, when a vibration wave device such as a plurality of vibration wave motors is applied as a high precision motor,
In applications that need to work in concert with each other,
A vibration wave motor is mounted when the driving state of at least one vibration wave device such as a vibration wave motor (hereinafter abbreviated as a vibration wave motor) is slightly different from the driving state of another driving motor or another vibration wave motor. It is conceivable that the performance of the entire device is significantly reduced.

For example, when the vibration wave motor is applied to an electrophotographic color image forming apparatus, the vibration wave motor is used to drive an image carrier such as a photosensitive drum and a recording material handling means such as a transfer material conveying belt for conveying the recording material. A vibration wave motor is used. In particular, eliminating uneven rotation and position control errors
This is because it is indispensable for remarkable improvement in image quality.

Further, since the laser exposure scanning system requires a high-speed rotation of about 10,000 to 30,000, a DC using a bearing or an air bearing without using a bearing is used for the rotation axis of the polygon mirror. Brushless motors are often used. It is necessary to operate the driving means other than such a vibration wave motor and at least one or more vibration wave motors in a coordinated manner.

As described above, in the conventional image forming apparatus, there is a problem that image deterioration is caused due to uneven rotation when the photosensitive drum is driven at a low speed.

In a laser scanning type image forming apparatus,
There is a problem that it is difficult to change the laser scanning cycle, and pitch unevenness in the sub-scanning direction is conspicuous.
In particular, in the color image forming apparatus, there is a problem that the uneven rotation of the photosensitive drum of each color causes significant image deterioration such as uneven color of a reproduced color image.

Particularly, in a color image forming apparatus which has an image forming section for each color corresponding to the Y, M, C, and K toner colors and forms a color image at high speed, recently,
A system having four photosensitive drums and four laser scanning means has been proposed, and it is an important subject to precisely match the registration of images of each color. That is, when the registration of the toner images of the respective colors is not precise, a toner image portion protruding particularly at the character portion or the edge portion of the fine line is generated, and it becomes very difficult to see. Also, regarding the gradation image, since the overlapping of the toner images of the respective colors does not become uniform, the image becomes unnatural as uneven color and becomes unsightly.

With respect to the registration in the main scanning direction, if there is a registration deviation, an area will be formed in the overlapping portion of the toner images of the respective colors.
There has been proposed a method of precisely matching color toner images.

As for the registration in the sub-scanning direction, there has been proposed a method of precisely adjusting the registration in the sub-scanning direction in the unit of one line by adjusting the writing timing of the image signal in the unit of one line.

However, in the laser scanning type image forming apparatus, it is difficult to finely adjust the registration of less than one line in the sub-scanning direction. For example, a method has been proposed in which a sub-scan registration correction of less than one line is finely adjusted by finely adjusting the optical path of a laser beam by making a mirror constituting a laser scanning optical system movable. However, the laser scanning optical system becomes complicated, and means for precisely moving a mirror or the like is required, so that the apparatus becomes complicated, and there are disadvantages such as an increase in size, an increase in cost, and a complicated adjustment process.

In a laser scanning type image forming apparatus, a method has been proposed in which the photosensitive drum is rotated by an oscillating wave device to reduce the rotation unevenness of the photosensitive drum. However, there is a problem that the cooperative operation cannot be performed, and the line interval unevenness of the reproduced image cannot be reduced.

Further, when the vibration wave device is used for rotationally driving the intermediate recording medium or the recording medium carrier, there is a problem that the registration when images of a plurality of colors are sequentially superimposed cannot be precisely adjusted.

On the other hand, in the image forming apparatus, a method has been proposed in which the polygon mirror motor is stopped or driven at a low speed during standby in order to limit the life of the polygon mirror motor, reduce noise, and reduce power consumption.

In such a case, it is necessary to start the polygon mirror motor up to a predetermined number of revolutions before starting the image formation. Even if it is attempted to obtain a BD signal by turning on the laser before rising to a sufficient number of rotations, a predetermined BD
Since only a BD signal having a cycle longer than the signal cycle can be obtained, if the speed difference of the vibration wave device is finely adjusted in such a defective BD cycle, accurate and smooth rotation control cannot be performed.

In the case where the polygon mirror motor is an air bearing, the life of the polygon mirror motor is significantly improved. It is possible to continuously rotate at the same predetermined rotational speed. Therefore, the BD signal is generated by the BD detection means in a very short time after the laser is turned on. Therefore, it is possible to enter a mode for finely adjusting the speed difference of the vibration wave device in a short time.

(Abnormal stop, uneven rotation) However, if a BD signal is not detected due to some problem such as a problem with laser lighting, the speed difference control of the vibration wave device based on the BD signal cannot be performed properly, and the photosensitive drum or Rotational unevenness of the vibration wave device that drives the transfer belt or the like increases. Depending on the control amount of the speed difference control, the frequency of the driving pulse applied to the vibration wave device becomes an extremely low frequency, and a trouble that the rotation of the vibration wave device stops abnormally has occurred. Furthermore, uneven speed or abnormal stoppage of the vibration wave device causes frictional scratches between the photosensitive drum and the transfer belt, causing problems such as poor image quality and increased component replacement costs.

(During Start / Stop Shift) When the image forming apparatus is started, it is necessary to smoothly start the vibration wave device from a stopped state to a predetermined rotation speed as a driving state, and to end image formation. When stopping the vibration wave device, it is necessary to smoothly fall from a predetermined speed to a stop state as a driving state of the vibration wave device.

Therefore, in such a case, it is necessary to control the rotation speed of the vibration wave device at an appropriate speed such that the period of the encoder pulse of the vibration wave device is longer than the period of the predetermined BD signal. . As such a control method, it is conceivable to compare the phase difference and the speed difference between the BD signal cycle and the encoder pulse. In this case, there is a possibility that precise speed difference control cannot be performed within the BD signal cycle.

(Low-speed / high-speed mode) Various materials are known as recording media used for image formation, such as plain paper, cardboard, and OHP paper (transparent transfer material).
For example, a method has been proposed in which the process speed of image formation is reduced. On the other hand, in order to control the gloss of a toner image transferred onto a recording medium, a method has been proposed in which a fixing process speed of a heat fixing roller can be selected from a low speed, a standard speed, and a high speed. As described above, when changing the operation speed of the image forming apparatus to various speeds,
The speed of the oscillatory wave device can also be changed.

For example, when forming an image on thick paper or the like, the image forming process speed is reduced to 、 and the rotation speed of the fixing roller is also reduced to 、. It is conceivable that the driving speed of the vibration wave device for driving the photosensitive drum and the transfer belt is reduced to half while keeping the normal rotation speed. At this time, the writing operation of the image data in line units is adjusted according to the process speed so that the reproduced image is not reduced in the sub-scanning direction.

When the speed of an oscillating wave device such as a photosensitive drum or a transfer belt rotates at half the standard speed, the encoder pulse period is generated at twice the standard speed.
However, if the rotation speed of the polygon mirror motor is the same as the standard speed, the BD signal period is also the same as the standard speed, and the encoder pulse period is twice as long as the BD signal period. In such a case, if the period and the phase difference between the BD signal and the encoder pulse are controlled so that the phase difference becomes substantially zero at a speed substantially equal to the laser scanning period, the speed difference and the phase difference of the vibration wave device are controlled. Therefore, the control amount for correcting the rotation of the motor greatly acts, and speed control without rotation unevenness cannot be performed.

[0040]

According to a first configuration of a vibration wave driving device for realizing the object of the invention according to the present application, a plurality of driving means including a vibration wave device operate in cooperation with each other, and a cooperative relationship is established. A vibration wave drive device having a drive control unit that synchronously drives the vibration wave device with respect to a certain drive unit, wherein the drive control unit performs a predetermined operation by driving the one drive unit every time. Based on the generated first signal and a second signal indicating the driving state of the vibration wave device, the vibration wave is controlled so that the second signal has a predetermined phase difference with respect to the first signal. A first control mode for driving and controlling the device; and a second control mode for driving and controlling the vibration wave device based on the second signal and a target value. If the synchronous drive of the device is not suitable, the second It is for selecting the control mode.

A second configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that a plurality of driving means including a vibration wave device operate in cooperation with each other, and one driving means in a cooperative relationship is provided. A driving control means for synchronously driving the vibration wave device, wherein the driving control means generates a first signal each time a predetermined operation is performed by driving the one driving means. A first signal generating unit that generates a pseudo signal having a period substantially the same as or different from the period of the first signal, and a second signal that represents a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device so that the second signal has a predetermined phase difference with respect to the first signal; and a pseudo signal and the second signal. Driving and controlling the vibration wave device based on the second In which a control mode.

A third configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that a plurality of driving means including a vibration wave device operate in cooperation with each other, and one driving means in a cooperative relationship is provided. A driving control means for synchronously driving the vibration wave device, wherein the driving control means generates a first signal each time a predetermined operation is performed by driving the one driving means. A first signal generating section for generating a pseudo signal and a pseudo signal generating section for sequentially generating a plurality of pseudo signals having substantially the same period or a different period from the first signal, and a second signal representing a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device such that the second signal has a predetermined phase difference with respect to the first signal based on the first signal and the second signal. Drive the vibration wave device based on the To those having a second control mode.

A fourth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that a plurality of driving means including a plurality of vibration wave devices operate in cooperation with each other, and one of the driving devices in a cooperative relationship. A vibration wave drive device having drive control means for synchronously driving the vibration wave device with respect to each means,
The drive control unit includes a first signal generation unit that generates a first signal each time a predetermined operation is performed by driving the one drive unit, and a pseudo signal having a period substantially the same as or different from the first signal. A pseudo signal generation unit that generates a signal, wherein the second signal has a predetermined phase difference with respect to the first signal based on a second signal indicating a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device, and a second control mode for driving and controlling the vibration wave device based on the pseudo signal and the second signal. And the second control mode can be selected by the selection means.

A sixth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that a plurality of driving means including a plurality of vibration wave devices operate in cooperation with each other, and one of the driving devices in a cooperative relationship. A vibration wave drive device having drive control means for synchronously driving the vibration wave device with respect to each means,
The drive control unit includes a first signal generation unit that generates a first signal each time a predetermined operation is performed by driving the one drive unit, and a plurality of signals having substantially the same cycle or a different cycle from the first signal. And a pseudo-signal generation unit for sequentially generating pseudo-signals, wherein the second signal is in a predetermined position with respect to the first signal based on a second signal indicating a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device so as to have a phase difference, and a second control mode for driving and controlling the vibration wave device based on the pseudo signal and the second signal, The first control mode and the second control mode can be selected by selection means.

A sixth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that the selecting means selects the second control mode when the vibration wave device is started. .

A seventh configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that the selecting means selects the second control mode when the vibration wave device is stopped. .

According to an eighth aspect of the vibration wave driving device for achieving the object of the present invention, the selecting means selects the second control mode when the output state of the first signal is abnormal. It is something to do.

A ninth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is such that the selecting means is selected according to a non-driving body driven by the vibration wave motor. It is.

A tenth structure of the vibration wave driving device for realizing the object of the invention according to the present application is that the one driving means is an electromagnetic motor.

According to an eleventh configuration of the vibration wave driving device for realizing the object of the invention according to the present application, the vibration wave device is a vibration wave motor.

The twelfth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is to apply a frequency signal to an electro-mechanical energy conversion element to excite a driving wave to obtain a driving force 1 or A vibration wave driving device that drives and controls a plurality of vibration wave devices to operate in cooperation with another driving device, wherein a rotation detection unit that detects a rotation state of the vibration wave device, and an operation of the driving unit. A timing signal generating means for generating a pseudo-timing signal, and a pseudo-timing signal generating means for generating a pseudo-timing signal. The driving of the vibration wave device is performed by one of the timing signal and the pseudo-timing signal. The state is finely adjusted.

A thirteenth configuration of the vibration wave driving device for realizing the object of the present invention according to the present application is to apply a frequency signal to an electro-mechanical energy conversion element to excite a driving wave to obtain a driving force 1 or A vibration wave driving device that drives and controls a plurality of vibration wave devices to operate in cooperation with another driving device, wherein a rotation detection unit that detects a rotation state of the vibration wave device, and an operation of the driving unit. And finely adjusting the driving state of at least one or more of the vibration wave devices by using a timing signal generating means generated in association with the second timing signal different from a cycle generated based on the timing signal. It was done.

A fourteenth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is one that obtains a driving force by exciting a driving wave by applying a frequency signal to an electro-mechanical energy conversion element. Or a vibration wave driving device that drives and controls a plurality of vibration wave devices so as to operate in cooperation with one or more other driving devices, and a rotation detection unit that detects a rotation state of the vibration wave device; A timing signal generating unit that is generated in association with the operation of the driving unit, and a pseudo timing signal generating unit that generates a pseudo timing signal, and any one of the timing signal and the pseudo timing signal, A first mode for finely adjusting the driving state of the vibration wave device, and finely adjusting the driving state of the vibration wave device by at least one of the timing signal and the pseudo timing signal. And it has a second mode without settling.

The fifteenth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as the twelfth or fourteenth embodiment.
And a mode in which at least one of the timing signal and the pseudo timing signal is deactivated.

The sixteenth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as the twelfth or fourteenth embodiment.
And a mode in which an adjustment amount for finely adjusting a driving state of at least one or more vibration wave devices is changed according to at least one of the timing signal and the pseudo timing signal.

The seventeenth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as the twelfth or fourteenth embodiment.
In the configuration of (1), an adjustment amount for finely adjusting a driving state of at least one or more of the vibration wave devices is determined by a non-volatile memory means or a rewritable memory as needed by at least one of the timing signal and the pseudo timing signal. Means or register means.

The eighteenth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as the twelfth or fourteenth embodiment.
Wherein at least two or more of the driving sources perform a speed changing operation in cooperation with each other when at least starting, stopping, and changing the speed of the driving sources using the vibration wave device and the driving unit. It is.

The nineteenth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as the twelfth or fourteenth embodiment.
And a timing signal selecting means for selecting one of the timing signal and the pseudo-timing signal as a second timing signal.

According to a twentieth configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the nineteenth configuration described above, the vibration wave driving device according to the second timing signal selected by the selection means is used. The driving state of the vibration wave device is controlled using a rotation detection signal from a rotation detecting means for detecting the rotation state of the vibration wave device.

The twenty-first configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as that of the twelfth, fourteenth,
In the configuration of 5, 16, 17, 18, 19 or 20, the vibration wave is generated based on a phase difference or a speed difference between at least one of the timing signal and the pseudo timing signal and the rotation detection signal. The driving state of the device is controlled.

According to a twenty-second configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the twelfth, thirteenth, or fourteenth configuration, the vibration wave device and the driving means are used, At least when starting, stopping, and changing the speed, a timing signal used for speed control can be selected from the various timing signals according to a target speed, and at least two or more driving sources cooperate to change the speed. It is made to work.

According to a twenty-third configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the twelfth, thirteenth, or fourteenth configuration, the target value of the rotation speed of the vibration wave device is determined by the timing signal. Is finely adjusted.

According to a twenty-fourth configuration of the vibration wave driving device that achieves the object of the invention according to the present application, in the twelfth, thirteenth, or fourteenth configuration, the vibration wave device is a vibrating body in which a vibration wave is excited. And the vibrating body and the contact body that comes into pressure contact with each other perform relative motion.

According to a twenty-fifth configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the twelfth, thirteenth, or fourteenth configuration, the rotation detecting means detects a rotation speed of the vibration wave device. Speed detecting means.

According to a twenty-sixth structure of the vibration wave driving device for realizing the object of the invention according to the present application, in the twenty-fifth structure, the rotation detecting means detects a rotation amount of an output shaft of the vibration wave device. It is a rotary encoder.

A twenty-seventh configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the same as the twelfth, thirteenth, or fourteenth configuration except that the timing signal and the rotation detection signal from the rotation detecting means are different from each other. However, the rotation of the vibration wave device is controlled so as to rotate substantially synchronously.

The twenty-eighth structure of the vibration wave driving device for realizing the object of the invention according to the present application is the same as that of the twelfth to twenty-seventh embodiments.
In any one of the above configurations, the driving state of the vibration wave device is finely adjusted by a pseudo timing signal until the rotation speed of the vibration wave device reaches a substantially predetermined rotation speed, and thereafter by the timing signal. It is like that.

According to a twenty-ninth configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the twelfth, thirteenth, or fourteenth configuration, at least one of the timing signal and the pseudo-timing signal is provided. It has data correction means for correcting speed difference information obtained from the rotation detection signal.

According to a thirtieth configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the twenty-ninth configuration, the data correction unit is a storage unit for storing correction information. is there.

According to a thirty-first configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the thirtieth configuration, the data correction means selects one of a plurality of correction data groups. It is configured to be usable.

According to a thirty-second configuration of the vibration wave driving device for realizing the object of the invention according to the present application, in the twelfth, thirteenth, or fourteenth configuration, the vibration wave driving device includes at least one of the pseudo timing signal and the timing signal. The fine adjustment control of the driving state of the wave device can be deactivated.

A first configuration of an image forming apparatus for realizing the object of the invention according to the present application includes a vibration wave driving device having any one of the above-described configurations, and includes the vibration wave device and the driving unit as a driving source. Used, in order to change at least one of an image forming speed and various process processing speeds in accordance with at least an apparatus operation corresponding to a type of a recording medium and an apparatus operation that brings a special effect to a reproduced image, the vibration wave device and The speed of the driving unit is changed to a speed lower than or higher than the speed at the time of normal image formation.

A second configuration of the image forming apparatus for realizing the object of the invention according to the present application is that the driving means is a polygon mirror motor of a laser beam scanning system.

In a third configuration of the image forming apparatus for realizing the object of the invention according to the present application, the timing signal is substantially equal to a BD signal generated by a BD detection unit that generates a main scanning timing by laser beam scanning. This is a timing signal generated at a timing.

In a fourth configuration of the image forming apparatus for realizing the object of the invention according to the present application, the timing signal is a timing signal generated after a lapse of a predetermined time from the BD signal.

In a fifth configuration of the image forming apparatus for realizing the object of the invention according to the present application, the timing signal is a timing signal obtained by counting a BD signal a predetermined number of times.

A sixth configuration of the image forming apparatus for realizing the object of the invention according to the present application is such that, in the configuration of the second, third or fourth image forming apparatus, when a BD signal is not detected at a predetermined cycle, Fine adjustment of the driving state of the vibration wave device is performed using the prepared pseudo BD signal as the timing signal.

A seventh configuration of the image forming apparatus for realizing the object of the invention according to the present application is a configuration of any one of the above-described image forming apparatuses, wherein a plurality of image carriers arranged in parallel along the transfer material conveying direction are provided. The body is driven by each of the vibration wave devices.

An eighth aspect of the image forming apparatus for realizing the object of the invention according to the present application is the transporting means for transporting a transfer material to a transfer position with the image carrier in any one of the image forming apparatuses described above. Is driven by the vibration wave device.

A ninth configuration of the vibration wave driving device for realizing the object of the invention according to the present application is the configuration of any one of the image forming apparatuses described above, and the images on the image carrier are sequentially transferred and superimposed. An intermediate transfer unit configured to hold an image; and a transport unit configured to transport a transfer material to a transfer position with the intermediate transfer unit. At least one of the intermediate transfer unit and the transport unit is driven by the vibration wave device. It is like that.

[0081]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) In a first embodiment, the present invention is applied to an electrophotographic image forming apparatus having four photosensitive drums. 1 shows a main configuration of an embodiment.

The transfer material conveying belt roller 348 shown in FIG.
Driven by a vibration wave motor 11 (not shown), Y, M,
Each photosensitive drum 34 involved in the formation of C and K toner images
2, 343, 344, and 345 are independently driven by vibration wave motors 12, 13, 14, and 15 (not shown). In addition, these five vibration wave motors 11 to 15
Each is controlled by an independent drive control circuit. FIG. 2 shows a block diagram of a drive control circuit for one vibration wave motor for simplicity of description. The cooperative operation between the vibration wave motors is performed by a CPU (not shown).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view of a color image forming apparatus according to an embodiment of the present invention. This color image forming apparatus includes a color reader section and a color printer section.

In FIG. 1, reference numeral 101 denotes a CCD, and 311 denotes a CCD 101.
, An image processing unit, 301 a platen glass (platen), and 302 a document feeder (DF)
(There is also a configuration in which a mirror pressure plate (not shown) is mounted in place of the document feeder 302). Reference numerals 303 and 304 denote light sources (halogen lamps or fluorescent lamps) for illuminating the document.
05 and 306 are reflectors for condensing the light from the light sources 303 and 304 on the original, 307 to 309 are mirrors, 310 is a lens for condensing the reflected light or projection light from the original on the CCD 101, and 314 is a halogen lamp 303 and 314. A carriage accommodating 304, reflectors 305 and 306, and a mirror 307;
315, a carriage that houses the mirrors 308, 309;
313 is an interface (I / F) with another IPU, etc.
Department. The carriage 314 is moved at a speed V and the carriage 315 is moved at a speed V / 2 mechanically in the direction perpendicular to the electrical scanning (main scanning) direction of the CCD 101, thereby scanning the entire surface of the document (sub scanning). ).

In FIG. 1, reference numeral 317 denotes an M image forming unit, 318 denotes a C image forming unit, 319 denotes a Y image forming unit, and 320 denotes a K image forming unit. The unit 317 will be described in detail, and description of 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 laser exposing unit 210. 321 is a charger, which is 150
The surface of the photosensitive drum 342 rotating at a speed of mm / sec is charged to a predetermined potential to prepare for formation of a latent image.

The charger 321 includes a sleeve (not shown) and 25
By rotating at a speed of 5 mm / sec, charging is performed by forming a dielectric brush with a low-resistance ferrite carrier. 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.
The image is transferred to a recording paper on the recording medium 33. After this transfer, the toner 503 remaining on the photosensitive drum 342 is once taken into the charger 321 to change the electrostatic characteristics and return it to the photosensitive drum 342 again. The developing unit 322 collects and reuses the toner. .

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 supplied by the pickup rollers 339 and 338 onto the transfer material transport belt 333 which is moved at 150 mm / sec by the paper feed rollers 336 and 337 one by one. The fed recording paper is charged by the adsorption charger 346.

Reference numeral 348 denotes a transfer material transport belt roller which drives the transfer material transport belt 333 and
The recording paper and the like are charged in pairs with the transfer material transport belt 3.
The recording paper or the like is adsorbed to the reference numeral 33.

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 section 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 toner attraction and prevent image disturbance,
After the toner image is thermally fixed by the fixing device 334, the toner image is discharged to a paper discharge toner 335. Also, the transfer material transport belt 33
3 is neutralized by the internal / external static eliminator 353.

FIG. 11 is a block diagram showing a configuration of a control device of a vibration wave motor (a vibration wave device such as a vibration wave motor) according to a first embodiment of the present invention.

Now, an example will be described in which a clock output from the oscillator 701 is used as a common reference clock as a reference clock for a control device that controls the driving of each vibration wave device. The clock is also input to the PLL control circuit 211 and the polygon mirror motor 206
It is also used for driving control. It is also used as a clock for a video signal for forming an image and a clock for driving a laser. Further, even if the video signal clock and the laser driving clock for image formation are not shared with the vibration wave driving clock and the polygon mirror motor driving control clock, the scope of the present invention is not deviated. Can be applied.

In this embodiment, the video signal system, the polygon mirror motor system, and the vibration wave device system share a common clock, but it goes without saying that various applications are possible without departing from the gist of the present invention. For example, the video signal system clock and the drive system clock can be configured by different oscillators.

Since the image formation on the photosensitive drum of each color has the same configuration, the laser exposure scanning system for one color will be described.

FIG. 10 is a diagram for explaining the configuration of the scanner motor 206 shown in FIG.

In FIG. 10, reference numeral 801 denotes a rotor of the scanner motor 206, and four sets of magnetic pole patterns are magnetized per rotation on a permanent magnet. Further, a polygon mirror 218 is fixed via a support shaft 802 fixed to the rotor 801. In the present embodiment, the polygon mirror 21
8 has eight surfaces.

When the scanner motor 206 rotates, the FG
The sensor 207 generates four pulses per rotation from the magnetic pole pattern magnetized on the rotor 801,
The FG pulse is output after being shaped by the waveform shaping circuit 214.

On the other hand, the laser light emitted from the laser 205 is applied to the polygon mirror 2 rotating in the same direction as the rotor 801.
The BD sensor 203 outputs a BD signal which is a reference signal in the main scanning direction. Therefore, two BD signals are output while the FG pulse is output once. The photosensitive drum 201 is scanned, and B
An electrostatic latent image of one line unit is sequentially formed on the photosensitive drum by a video signal synchronized with the D signal.

FIG. 12 is a timing chart for explaining the relationship between the BD signal from the BD detection sensor 203 and the FG pulse from the FG waveform shaping circuit 214 shown in FIG.

In FIG. 12, reference numeral 901 denotes a BD signal;
2 is the FG pulse.

The polygon mirror 218 shown in FIG.
Surface, the magnetic pole pattern of the rotor 801 is 4 per rotation.
Since one pulse is generated, one FG pulse is output while two BD signals 901 are output. Further, as described above, since the rotor 801 and the polygon mirror 218 are fixed, they rotate the same, and the BD signal 901 is always output with the phase difference time T0 based on the FG pulse 902.

In FIG. 2, 1 is a pulse generator,
A pulse corresponding to the input frequency data and pulse width data is output in two phases. These two-phase pulses are output with a phase difference of 90 °. The pulse generator 1 is entirely constituted by a digital circuit in order to reduce the cost of the circuit. Here, the configuration and operation of the pulse generator 1 will be described with reference to FIG.

FIG. 5 is a block diagram showing an internal circuit of the pulse generator 1. Reference numeral 8 denotes a pulse generator for determining the period of the driving pulse.
This is a bit counter and performs only down counting.
In this counter 8, when the count value becomes 0, the carry output becomes high level. Since the carry output is connected to the load input, the counter 8 is a ring counter whose cycle is the drive frequency data.

9a and 9b are 9-bit counters for determining the pulse width of the drive pulse, and perform only a down counter. In these counters 9a and 9b, when the load input becomes high level, pulse width data is loaded, and when the count value becomes 0, the carry output becomes high level. The counter 9a is for A-phase driving, and the counter 9b is for B-phase driving.

Reference numeral 10 denotes a 10-bit equal comparator, which is used when the count value of the counter 8 matches the value obtained by shifting the frequency data to the right by 2 bits, that is, when the counter 8 counts a quarter of the frequency data. The output goes high.

Reference numerals 11a and 11b denote RS flip-flops, whose rising and falling edges are determined by the S input and the R input, respectively. The RS flip-flop 11a is for the A phase, and rises at the carry output of the counter 8 and falls at the carry output of the counter 9a. That is, a pulse which becomes high level for a time corresponding to the pulse width data is output with the frequency data as a cycle.

The RS flip-flop 11b is for the B phase, rises when the output of the equal comparator 10 goes high, and falls by the carry output of the counter 9b. As a result, the RS flip-flop 11b
Outputs a pulse having the same frequency and pulse width as the A-phase, but having a phase difference of 90 ° in time. In this description, the frequency data is the command value of the drive pulse cycle,
The actual frequency is a value proportional to the reciprocal of the frequency data.

In this embodiment, for simplicity of explanation, the phase difference between the A phase and the B phase is always the same, and the vibration wave motor rotates in only one direction. The outputs of the RS flip-flops 11a and 11b may be switched according to the rotation direction using a selector (not shown).

Returning to FIG. 2, reference numeral 2 denotes a booster, which has, for example, a circuit configuration as shown in FIG. In the boosting means 2,
At the frequency of the pulse output from the pulse generator 1, the voltage is increased to a voltage corresponding to the pulse width.

Reference numeral 3 denotes a traveling wave type vibration wave motor (USM), which boosts each piezoelectric element (not shown) as an electro-mechanical energy conversion element which is arranged at a position shifted by ４λ. A two-phase AC voltage (A-phase drive signal, B-phase drive signal) boosted in 3 is applied. When the two-phase drive signal is input to each piezoelectric element, the friction drive surface of the drive unit of the vibrating body moves circularly or elliptically, and the moving body that is in pressure contact with the friction drive surface is frictionally driven. . For example, an output shaft is fixed to the center of rotation of the moving body, and a photosensitive drum and a transfer material conveying belt roller are directly connected to the output shaft to transmit a driving force.

Reference numeral 4 denotes an encoder for detecting the rotation of the vibration wave motor. The rotation is detected by attaching the output shaft of the vibration wave motor 3 to the shaft of the encoder 4. A pulse corresponding to the rotation of the vibration wave motor 3 is output from the encoder 4. The pulse from the encoder 4 is a speed difference detector 5
Is input to the BD speed difference detector 21.

The speed difference detector 5 detects the difference between the period of the pulse from the encoder 4 and the target pulse period. Since the output value is detected based on the pulse period, the output value is a value proportional to the difference between the reciprocal of the drive speed and the reciprocal of the target speed.

FIG. 6 is a block diagram showing a circuit configuration of the speed difference detector. In FIG. 6, reference numeral 13 denotes a means for detecting a rising edge, and when the rising edge of the encoder pulse enters, a signal L13 which becomes high level for one cycle of the clock is output. The rising edge detecting means 13 includes a flip-flop, an AND gate, and the like (not shown). Reference numeral 14 denotes an 8-bit down counter, which loads target speed data corresponding to a target encoder pulse cycle when the load input goes high. When the load input is at the low level, the count is reduced by one, and the time until the rising edge of the next encoder pulse is counted.

Reference numeral 15 denotes a register with enable.
When the enable input is at a high level, an 8-bit input (D
[7. . 0]) is written to the register, and the value of the register is held when the enable input is at the low level.

With the configuration as shown in FIG. 6, when the encoder pulse input changes from the low level to the high level, the value of the 8-bit down counter 14 is written into the register 15 and at the same time the data of the 8-bit down counter 14 is loaded. . In other words, the value obtained by counting the difference between the cycle of the encoder pulse and the target cycle by the clock is always the register 15
Will be updated.

FIG. 6 shows a configuration example of the BD speed difference detector 21. FIG. 9 shows an example of a timing chart for explaining the operations of the speed difference detector 5 and the BD speed difference detector 21.

In FIG. 6, reference numeral 61 denotes a means for detecting the rising edge of the BD signal. When the rising edge of the BD signal enters, a signal L61 which becomes high level for one cycle of the clock is output. The rising edge detecting means 61 of the BD signal is constituted by a flip-flop (not shown), an AND gate, and the like. Reference numeral 62 denotes an 8-bit up counter which loads target BD speed difference data corresponding to a time difference between a target BD signal and an encoder pulse when the load input becomes a high level. Normally, zero is loaded as the target BD speed difference data. That is, allowable target BD speed difference data is set as the speed difference between the speed of the polygon motor and the speed of the vibration wave motor. When the load input is at a low level, the count is incremented by one.

Reference numeral 63 denotes a register with enable.
When the enable input L13 is at a high level, an 8-bit input (D [7..0]) is written to the register. When the enable input L13 is at a low level, the value of the register 63 is held.

With the configuration of the BD speed difference detector as shown in FIG. 6, since the enable input L13 is a rising edge signal of the encoder pulse of the vibration wave motor, when the BD signal changes from the low level to the high level, the enable input L13 becomes high. Zero is loaded into the bit counter 62 as target BD speed difference data, and the value of the 8-bit counter 62 is written into the register 63 when the encoder pulse input changes from low level to high level. That is, the value obtained by counting the difference between the cycle of the encoder pulse and the cycle of the BD signal by the clock is always updated and written in the register 63.

Reference numeral 64 denotes a BD speed difference memory 64, to which the BD speed difference data L63 held in the register 63 is input as an address, and outputs BD speed difference correction data L21 corresponding to the input information. In the BD speed difference memory 64, how to correct the speed difference detection result obtained from the encoder pulse of the vibration wave motor with respect to the input BD speed difference data to perform the drive control of the vibration wave motor Information has been written in advance.

Returning to FIG. 2, reference numeral 22 denotes an adder (adder) to which the detection result L15 of the speed difference detector 5 and the BD speed difference correction data L21 are inputted, and the addition result L22 is used as a new speed difference detection value. As a result, the address is input as the address L22 of each of the memories 6a and 6b.

Reference numeral 6a denotes a memory for frequency control, and 6b denotes a memory for pulse width control. The detection result of the speed difference detector 5 and the addition result L22 of L21 are input as addresses, respectively, and are stored in accordance with the input information. Output the corresponding data. Each of the memories 6a and 6b has a frequency (memory 6) corresponding to an input speed (pulse period of the encoder).
a), information on how to control the pulse width (memory 6b) is written in advance.

7a is an adder for frequency control (adder), 7
b denotes an adder for pulse width control. Adder 7
Both a and 7b hold preset initial values (holding information) while the driving of the vibration wave motor 3 is off. When the driving of the vibration wave motor 3 is turned on,
A configuration in which the adder 7a adds information input from the frequency control memory 6a to the held information at certain intervals and holds the addition result, and adds the information to the held information at certain intervals and holds the addition result. Has become.

The outputs of the adders 7a and 7b are input to the pulse generator 1 as frequency data and pulse width data. The adders 7a and 7b are configured by 16 bits.
The frequency control adder 7a outputs the upper 10 bits of the addition result and the pulse width control adder 7b outputs the upper 8 bits of the addition result to the pulse generator 1, respectively. This prevents the frequency and pulse width from changing abruptly.

The vibration wave motor 3 having the configuration described above
The speed is controlled based on the information written in the memories 6a and 6b.

Hereinafter, a specific control method will be described in detail.

FIG. 7 is a diagram in which information written in the frequency control memory 6a is blotted. The memory 6a has an address of 8 bits and data of 8 bits. In FIG. 7, the horizontal axis represents the address of the memory 6a, that is, the value obtained from the speed difference detector 5, and is indicated with a sign. The vertical axis indicates the data stored in the memory 6a, that is, the amount of addition of the frequency, which is indicated by a sign. For example, when control is performed with the encoder 4 having the number of pulses per rotation of the vibration wave motor 3 of 3600 to set the target speed at 1.0 s ⁻¹ , if the clock of the speed difference detector 5 is 0.36 MHz, the target speed data is According to the following equation (1), 100
Is obtained.

0.36 [MHz] / (1.0 [s ⁻¹ ] × 3600 [p / r]) = 100 (1) Therefore, the speed difference detector 5 outputs 10 as target speed data.
0 is input. When the driving speed of the vibration wave motor 3 is lower than the target, the down-count by the speed detector 5 becomes 10
Since the processing is performed more than 0, a value smaller than 0 (negative value) is output from the memory 6a. On the other hand, when the drive speed is faster than the target speed, a value larger than 0 (positive value) is output from the memory 6a.

Thus, when the address is a negative value, the driving speed is lower than the target, and if the driving frequency is lowered, that is, if the data is set to a positive value, the speed is controlled to the target speed. You. When the address is a positive value, the driving speed is higher than the target speed, and if the data is set to a negative value, the data is controlled to the target speed.

In FIG. 7, the area A has an address of -5.
0, that is, the speed 6.6 s obtained by the following equation (2)
^This is an area when a driving speed higher than ^-1 is detected.

0.36 [MHz] / ((100 + 50) × 3600 [p / r]) = 0.67 [s ⁻¹ ] (2) In FIG. 7, constant data of 100 is output in the region A. . In the area B, the address is from -50 to -2.
0, that is, from equation (2), 0.67s ^{- 1}
This is the area when the driving speed between 0.83 s ^-1 is detected. In this case, as shown in FIG. 7, data proportional to the difference between the detected encoder pulse periods is output.
The region C is a region when a driving speed between 0.83 s ^-1 and 1.25 s ^-1 is detected.

In this case, as in the case of the area B, data proportional to the difference between the detected encoder pulse periods is output, but the data change rate is smaller than that of the area B. Similarly, in the area D (1.25 s ^-1 to 2.0 s ^-1 ), the data change rate is larger than that in the area C,
(At a time later than 2.0 s ^-1 ), a constant value of -100 is output as data.

As described above, by changing the data change rate according to the area, when the speed difference between the target speed and the detected drive speed exceeds a certain range (A and E areas), When the operation of the vibration wave motor 3 is controlled with a data value as large as possible without becoming unstable, and when the speed difference is within the above range but the speed difference is relatively large (when the speed difference is in the region between B and D), The frequency is largely changed according to the speed difference, and when the speed difference is close to 0 (when the frequency is in the region C), the frequency is changed slightly according to the speed difference.

FIG. 8 shows a pulse width control memory 6b.
FIG. 9 is a diagram in which information written to the data is plotted. FIG. 8 also shows the address (speed information) on the horizontal axis and the data (output) on the vertical axis, similarly to FIG. In FIG. 8, the area A
7 to E show the same regions as those in FIG. When the data is configured as shown in FIG. 8, the frequency control greatly works A,
In the areas B, D and E, the memory 6a for controlling the pulse width is used.
Outputs a small small value from the pulse width control memory 6a in the area C where the frequency control does not work very much.
As a result, a large value corresponding to the speed difference is output.

As described above, when the vibration wave motor 3 is controlled, when the drive speed of the vibration wave motor 3 is far from the target speed, the weighted speed control mainly based on the frequency control is performed. Therefore, the driving speed quickly approaches the target speed. When the driving speed of the vibration wave motor 3 approaches the target speed, weighted speed control mainly performed by controlling the pulse width (voltage amplitude) is performed, and fine speed control without unevenness can be performed.

Since the frequency control and the pulse width control are always performed simultaneously, the unstable operation of the motor due to the conventional control switching can be prevented.

Further, in the present embodiment, a case has been described in which the data in the areas A and E in FIG. 7 and the data in the areas A, B, D and E in FIG. The data in these areas may be changed according to the address.

FIG. 13 is an example in which information written in the BD speed difference memory 64 is plotted. Memory 6
As 4, an address of 8 bits and data of 8 bits are used. In FIG. 13, the horizontal axis represents the address of the BD speed difference memory, that is, the register 6 of the BD speed difference detector 21.
This is a value obtained from 3 and is represented with a sign. The vertical axis represents data stored in the BD speed difference memory 64, that is, BD speed difference correction data, and is represented with a sign.

For example, the period of the BD signal determined by the laser scanning speed of the polygon mirror depends on the speed difference from the speed obtained from the encoder pulse of the vibration wave motor according to the information in the memory 64 as shown in FIG.
D speed difference correction data L64 is output.

(1) When the period of the BD signal is equal to the period of the encoder pulse Now, the period of the BD signal determined by the laser scanning speed of the polygon mirror is equal to the speed obtained from the encoder pulse of the vibration wave motor, and the speed difference Is zero, it is detected as a BD speed difference by a BD speed difference counter in accordance with the phase difference between the BD signal and the encoder pulse. That is, the time corresponding to the phase difference between the generation of the rising edge of the BD signal and the generation of the rising edge of the encoder pulse is detected by the BD speed difference detector. Are counted up by the number of clocks corresponding to the above, and the count value of the counter 62 is written into the register 63 when the encoder pulse edge is generated. For example, when a count value of 20 is written, BD speed difference correction data L21 = −10 is output from the memory 64, input to the adder 22, added to the speed difference information L15 of the speed difference detector 5, and added to the speed difference. It acts so that the value of information L15 decreases.

The speed difference information L22 corrected by the information of the BD speed difference detector is stored in the frequency control memory 6a,
Since the value is input to the address of the pulse width control memory 6b and the value of the speed difference information L15 has been reduced, the speed of the vibration wave motor set by the target speed data is controlled to slightly stop.

On the other hand, when the rising edge of the BD signal is generated after the rising edge of the encoder pulse is generated, this corresponds to the opposite phase as described above. In such a case, the counter 62 is cleared to zero. The value of the counter 62 at the time when the rising edge of the encoder pulse was previously generated is written to the register 63. Therefore, the time when the encoder pulse is generated earlier than the BD signal is detected by the BD speed difference detector 21.

For example, when a count value of -20 is written, the BD speed difference correction data L21 = +
10 is output, input to the adder 22, added to the speed difference information L15 of the speed difference detector 5, and acts to increase the value of the speed difference information L15.

The speed difference information L22 corrected by the information of the BD speed difference detector has the value of the speed difference information L15 increased by the BD speed difference correction data L21, so that the vibration wave set by the target speed data is used. Control is performed so as to slightly reduce the speed of the motor.

If the phase difference between the BD signal and the encoder pulse is substantially zero, the BD speed difference correction data L21 = 0 is output from the BD speed difference counter, and the value of the speed difference information L15 is directly used as L22. , So that the speed of the vibration wave motor set by the target speed data is controlled to be maintained.

As described above, the period of the BD signal determined by the laser scanning speed of the polygon mirror is equal to the speed obtained from the encoder pulse of the vibration wave motor.
When the speed difference is zero, the polygon motor is driven in accordance with the phase difference between the BD signal and the encoder pulse so that the cycle of the BD signal is equal to the cycle of the encoder pulse and within the predetermined phase difference. By rotation, according to the phase difference between the BD signal and the encoder pulse, the laser scanning speed by the rotation of the polygon motor is adjusted so that the cycle of the BD signal and the cycle of the encoder pulse are the same and within the predetermined phase difference. The rotational speed of the vibration wave motor can precisely cooperate. Further, by controlling the phase of the rotation phase of laser scanning by the polygon mirror and the phase of the encoder of the vibration wave motor, synchronous control is performed so that one encoder pulse is generated in one main scanning cycle.

(2) When the encoder pulse period is shorter than the BD signal period When the encoder pulse period is shorter than the BD signal period, the rising edge of the encoder pulse is generated before the rising edge of the BD signal is generated. Is generated, the count value of the negative value is written, and the BD speed difference correction data L21 of the positive value is output from the memory 64, input to the adder 22, and the speed difference detector 5 It is added to the speed difference information L15 to act to increase the value of the speed difference information L15. Since the value of the speed difference information L15 is increased by the BD speed difference correction data L21, the speed of the vibration wave motor set by the target speed data is controlled to be slightly reduced. Therefore, the speed control of the vibration wave motor is performed precisely so as to synchronize with the BD signal.

(3) When the encoder pulse cycle is longer than the BD signal cycle When the encoder pulse cycle is longer than the BD signal cycle, the rising edge of the BD signal is generated before the rising edge of the encoder pulse is generated. Is generated, the negative value of the BD speed difference correction data L21 from which the positive count value is written is output from the memory 64, input to the adder 22, and the speed difference detector 5 It is added to the speed difference information L15, and acts so that the value of the speed difference information L15 decreases. Since the value of the speed difference information L15 is reduced by the BD speed difference correction data L21, the speed of the vibration wave motor set by the target speed data is controlled to be slightly increased. Therefore, the speed control of the vibration wave motor is performed precisely so as to synchronize with the BD signal.

As described above, in the drive control of the vibration wave motor, the drive state of the vibration wave motor is finely adjusted by the timing signal generated in connection with the operation of the drive means provided separately from the vibration wave motor. By virtue of this, for example, as in this embodiment, the vibration is precisely synchronized with the BD signal generated in connection with the operation of the polygon mirror motor (DC brushless motor) provided separately from the vibration wave motor. Since fine adjustment control of the speed of the wave motor is performed,
Since a precise vibration wave drive speed control can be performed in synchronization with the laser scanning cycle, a relative error between the rotation of the photosensitive drum by the vibration wave motor and the laser scanning cycle is reduced.

For the sake of simplicity, the explanation has been made by taking as an example a photosensitive drum that is driven to rotate by a polygon mirror motor and a vibration wave motor in one image forming unit. It goes without saying that the present invention is also applicable to a color image forming apparatus having a plurality of image forming units.

As described above, according to the present invention, there is no variation in line spacing due to uneven rotation of the vibration wave motor, and it is possible to reproduce an image without unevenness in color, density, or registration.

[Activation of Vibration Wave Motor] When a vibration wave motor is used as a drive source for the photosensitive drum and the transfer belt of the image forming apparatus, when the image forming apparatus is started, the rotation from the stopped state to a predetermined rotation speed is smooth. It needs to be launched. If the relative speed difference between the photosensitive drum and the transfer belt occurs when the vibration wave motor is started, problems such as friction and scratches on the photosensitive drum and the transfer belt occur, and the durability life is deteriorated.

It is necessary to start the polygon mirror motor up to a predetermined number of revolutions before starting the image formation. In such a case, even if it is attempted to obtain a BD signal by turning on the laser before rising to a sufficient number of rotations, a predetermined BD
Only a BD signal having a cycle longer than the signal cycle can be obtained.

When the polygon mirror motor is an air bearing, it can be continuously rotated at the same predetermined rotation speed as during image formation even in the standby state.
A BD signal having a regular BD cycle cannot be obtained in the time from when the laser is turned on until the BD signal is generated by the BD detection means.

As described above, the BD as a timing signal generated in association with the rotation of the driving means (in this embodiment, the polygon mirror motor) provided separately from the vibration wave motor.
If the signal is also used to correct the speed unevenness of the vibration wave motor, when the vibration wave motor is started in a state where the BD signal cannot be obtained as a regular BD cycle, the BD signal and the encoder pulse The speed control of the vibration wave motor is not stably performed due to the speed difference and the phase difference from the above.

Therefore, the present embodiment is characterized in that, when the vibration wave motor is started, the information in the memory 64 for correcting the BD speed difference is made different from the information when the rotation is controlled at the normal rotation speed. I do.

For example, the memory capacity of the memory 64 is doubled, and all zeros are set in the first memory area so that the speed difference is not corrected by the BD speed difference detector 21 when the vibration wave motor is started. BD speed difference data such as is written in advance. In the second memory area, BD speed difference data for use in normal rotation control as shown in FIG. 13 and BD speed difference data for correcting a phase difference are written in advance. A memory bank switching signal BANK output by a CPU (Central Processing Unit) (not shown)
And the first and second memory areas can be selected. That is, [at start-up] BANK = Low: Select the first memory area.

[When the rotation speed reaches a predetermined value] BANK = Hig
h: Select the second memory area. And

When the image forming apparatus is started and the vibration wave motor is started, the CPU outputs BANK = Low and selects the information in the first memory area. 64 data outputs L
21 becomes zero. Even if the value of the BD speed difference correction data L21 from the BD speed difference detector 21 is added to the speed difference detection result L15 by the speed difference detector 5, the value of the speed difference detection result L15 is directly used as the speed difference information L22. , To the memories 6a and 6b.

Therefore, when the image forming apparatus is started, the BD
Even if there is a problem such as the presence or absence of a signal or a deviation of the BD signal cycle from a predetermined cycle, the encoder signal from the speed difference detector 5 is used instead of the BD signal,
The drive control of the vibration wave motor is performed based only on the speed difference information from the target speed data. For this reason, it is possible to prevent a problem that the rotational unevenness of the vibration wave motor is significantly increased due to the problem of the BD signal.

A CPU (not shown) reads the speed difference information of the speed difference detector 5 and, when detecting that the vibration wave motor has approached a predetermined target speed, outputs BANK = High.
The information of the second memory area is selected. Then, the drive control of the vibration wave motor with the BD speed difference corrected is performed using the BD signal and the encoder signal, so that the vibration wave motor without rotation unevenness can be further driven, and the BD signal and the BD signal Can be eliminated.

[Stopping the vibration wave motor] When the vibration wave motor is stopped, for example, when the vibration wave motor is used as the drive source of the photosensitive drum or the transfer belt of the image forming apparatus, when the image forming apparatus is stopped. It is necessary to smoothly fall from a predetermined rotation speed to a stop state. As in the case of starting the vibration wave motor, if a relative speed difference occurs between the photosensitive drum and the transfer belt, problems such as abrasion and scratches on the photosensitive drum and the transfer belt occur, thereby deteriorating the durability life.

[When the Vibration Wave Motor is Stopped During the Rotation of the Polygon Motor] In this embodiment, when the vibration wave motor is stopped, the information in the memory 64 for correcting the BD speed difference is rotated at a normal rotation speed. It is characterized in that the information is different from the information in the case of making it.

When stopping the vibration wave motor at the end of image formation, when the polygon mirror motor is rotating and a BD signal is being generated, the target speed of the vibration wave motor is sequentially reduced to a low speed in synchronization with the BD signal. By changing to the target speed, it is possible to smoothly change the speed. On the other hand, if laser scanning is continued until the photosensitive drum stops, the photosensitive drum will be inadvertently irradiated with laser light, and the life of the laser element will be shortened, and the photosensitive drum will be deteriorated. Failure to form images.)
cause.

Therefore, generally, when stopping the photosensitive drum, the laser light is often turned off. When the laser beam is turned off, a BD signal is not generated.
This causes a problem that the speed difference detector 21 cannot correct the speed difference correctly.

Therefore, in the present embodiment, when the vibration wave motor is stopped, the speed difference correction by the BD speed difference detector 21 is prevented from being performed by the information in the memory 64 for correcting the BD speed difference. Features. That is, a CPU (not shown)
Assuming that the memory bank switching signal BANK = Low output from the (central processing unit) [at stop] BANK = Low: Selects the first memory area.

Since the information of the first memory area is selected, the data output L21 of the memory 64 becomes zero regardless of the value of the output of the register 63. Even if the value of the BD speed difference correction data L21 from the BD speed difference detector 21 is added to the speed difference detection result L15 by the speed difference detector 5, the value of the speed difference detection result L15 is directly used as the speed difference information L22. , To the memories 6a and 6b.

Therefore, when the image forming apparatus is stopped, the BD
Even if there is a problem such as the presence or absence of a signal or a deviation of the BD signal cycle from a predetermined cycle, the encoder signal from the speed difference detector 5 is used instead of the BD signal,
The drive control of the vibration wave motor is performed based only on the speed difference information from the target speed data. Even when the laser is turned off when the image forming apparatus is stopped and the BD signal is not generated, the same drive control of the vibration wave motor is performed. Therefore, B
It is possible to prevent a problem that the rotational unevenness of the vibration wave motor is significantly increased due to the defect of the D signal.

As described above, the driving state of the vibration wave motor is finely adjusted by the timing signal generated in association with the operation of the driving means provided separately from the vibration wave motor, so that the vibration The uneven rotation of the wave motor can be reduced. In addition, the rotational speeds of the plurality of vibration wave motors and the rotational speed of the driving unit can be operated in cooperation. Further, at least when starting, stopping, and changing the speed of the vibration wave motor and the driving unit, at least two or more driving sources can perform the speed changing operation in cooperation.

As described above, according to the present embodiment,
It is possible to precisely cooperate with the rotation of the driving means other than the vibration wave motor, reduce unevenness in the line spacing of reproduced images, eliminate color unevenness, density unevenness, and enable precise registration. Become. Then, a beautiful reproduced image is obtained.

In this embodiment, an example is described in which the vibration wave motor is applied as a drive source in an image forming apparatus. However, it goes without saying that various applications are possible without departing from the gist of the present invention.

In the present embodiment, in the control operation when a relative speed difference between a plurality of vibration wave motors occurs,
Position control accuracy at the time of start / stop can be improved.

In the present embodiment, of the plurality of vibration wave motors, it is possible to reduce the rotational speed difference between the photosensitive drum and the transfer belt, and to reduce the wear of the photosensitive drum and the transfer drum.
Defects such as scratches can be eliminated.

In the present embodiment, the frequency control memory 6
a, a pulse width control memory 6b, and a BD speed difference memory 64 for storing BD speed difference correction data,
Although it has been described that predetermined data is written by the PU, it is needless to say that a plurality of register means, non-rewritable memory means, or a logic circuit may be used.

The frequency control memory 6a, the pulse width control memory 6b, and the BD speed difference memory 64 are set according to the number of rotations of the vibration wave motor and the number of rotations of the polygon mirror motor.
It is needless to say that the speed control can be performed in accordance with the required cost by setting the information of (1) to an optimum value according to the device configuration. In the present embodiment, a memory configuration of a plurality of banks is proposed using a memory having a data width of 8 bits, but the present invention is not limited to such a memory configuration.

In the present embodiment, the BD speed difference memory 64
If the BD speed difference correction process based on the information of
Although an example has been described in which a bank having a data value of zero is selected, it is needless to say that the present invention can be realized by other methods. For example, the present invention can also be realized by providing an AND gate circuit that makes the value of data zero by a logic circuit. A logic circuit in which a port output from a CPU (not shown) is connected to one input of the AND gate circuit and a data output of the BD speed difference memory 64 is connected to the other input of the AND gate circuit is configured by 8 bits. When not performing the BD speed difference correction process,
By setting the port signal to Low, the 8-bit data output of the BD speed difference memory 64 can be made zero.

The 8-bit zero data and the 8-bit data output from the BD speed difference memory 64 are connected to a CPU (not shown).
This can also be realized by providing a selector circuit that can be switched by a port output from the switch. As described above, it is needless to say that the present invention can be realized in various embodiments.

In this embodiment, the BD speed difference correction process using the BD signal has been described. However, the BD speed difference correction process is also applied to the pseudo timing signal as in the second and third embodiments. An application in which the speed difference correction processing is deactivated by switching information or the like is also possible.

(Second Embodiment) In this embodiment,
A timing signal generating unit that is generated in association with the operation of at least one driving unit provided separately from the vibration wave motor, and a second timing signal having a different cycle generated based on the timing signal; At least one
The driving state of the one or more vibration wave motors is finely adjusted.

In this embodiment, a case will be described where the vibration wave motor is driven at a lower speed than the standard speed. For example, in a conventional image forming apparatus,
There has been proposed a method of changing at least one of an image forming speed and various processing speeds in accordance with an apparatus operation corresponding to a type of a recording medium or an apparatus operation having a special effect on a reproduced image.

The recording paper used in the image forming apparatus includes:
A description will be given of a case where recording papers of various thicknesses are used and the process speed of the fixing process is reduced to 1/2 or 1/4 of the standard speed according to the basis weight of the recording papers of various thicknesses. I do.

Although a transparency sheet (transmissive film sheet or the like) for use in a transmission / reflection type projection device is also used, it is generally reduced to 1/2 or 1/4 of the standard speed. Often.

The case where the process speed is reduced to half of the standard speed will be described. When thick paper is designated by an operation unit panel (not shown), each turbulence and process processing speed are set so that the image forming process speed of the image forming apparatus becomes half the speed of the standard paper.

Even when the process speed is halved, it is assumed that the rotation speed of the polygon mirror motor is the same as when the process speed is the standard speed. At this time, by transmitting the image signal every other line and turning on the laser, the image does not need to be reduced in the sub-scanning direction. Also,
The image data may be padded in the sub-scanning direction. Various methods have been proposed, such as changing the scanning speed of the reading system in the sub-scanning direction, but are not limited to these methods.

FIG. 14 shows a main configuration of the present embodiment.

FIG. 16 shows an example of a main timing chart of the present embodiment.

This embodiment is characterized in that a second BD signal BD2 in which the period of the BD signal is changed is generated. For simplicity of explanation, a configuration using a polygon motor and a photosensitive drum driving vibration wave motor in an image forming unit for one color will be described as an example.
It is needless to say that the present invention can be applied to an image forming apparatus including a transfer belt and an image forming apparatus having an intermediate transfer member.

Reference numeral 24 denotes a 2-bit down counter.
It is configured to count down by the rising edge of the D signal. When a copy start button (not shown) is pressed, the image apparatus is started, and when the counter clear signal CLR from the CPU (not shown) is set to Low, the down counter 24 is cleared to zero. Next, when the polygon mirror motor reaches a predetermined number of revolutions, the laser is turned on,
A BD signal is generated. The BD signal is sent to the down counter 24
, A counter output LQ0 obtained by dividing the BD signal by 2 and a counter output LQ1 obtained by dividing the BD signal by 4 are generated. Here, a reference numeral 25 denotes a selector (not shown).
, The counter output LQ0 is selected, and BD2 as a BD signal divided by 2 is sent to the BD speed difference detector 21.

In this embodiment, the output of the speed difference detector 5 is input to the memories 6a and 6b, and the BD speed difference detector 21
Will be described in the case of inputting to the adder 23.

The adder 23 comprises a pulse width control memory 6b.
Is added to the BD speed difference correction data L21 of the BD speed difference detector 21, and the addition result L23 is input to the pulse width control adder 7b. With such a configuration, the speed control of the vibration wave motor performs weighted speed control mainly performed by the frequency control when the vehicle is separated from the target speed.
The drive speed quickly approaches the target speed. Then, when the driving speed of the vibration wave motor approaches the target speed, weighted speed control mainly performed by controlling the pulse width (voltage amplitude) is performed. Since the difference between the cycle of the BD signal BD2 and the cycle of the encoder pulse is very small, the pulse width control
It is suitable for performing fine and uniform speed control.

Further, for example, by writing BD speed difference correction data as shown in FIG. 13 in advance in the memory 64, it is possible to correct fine speed unevenness. It goes without saying that the optimum speed control can be performed by reconstructing various BD speed difference correction data. As shown in the timing chart of FIG. 16, the driving of the vibration wave motor is controlled such that the phase difference and the speed difference between the BD2 signal obtained by dividing the BD signal by 2 and the encoder pulse of the vibration wave motor are sufficiently reduced. .

In forming an image on a transparency sheet, it is generally necessary to lower the fixing speed further than that of thick paper in order to improve the transparency of the formed toner image and the beautiful color by improving the color mixture. There are often.
Depending on the size of the image forming apparatus, it is difficult to increase the distance between the image forming unit and the fixing unit,
Similarly, the image forming process speed and the fixing process speed are similarly reduced. In such a case, for example, when the speed of the vibration wave motor used for image formation is reduced to 1/4 of the standard speed, the selector 25 sets the selection signal SEL from the CPU (not shown) to High, thereby setting the counter. The output LQ1 is selected, and B divided by 4
BD2 as the D signal is sent to the BD speed difference detector 21.

As described above, by controlling the speed of the vibration wave motor using the BD signal BD2 at the 1/2 speed and 1/4 speed, the rotation speed of the polygon mirror motor is the same as that at the standard speed. The speed fluctuation of the vibration wave motor can be reduced while keeping the rotation speed.

In the present embodiment, an example of application to an image forming apparatus has been described, but it goes without saying that various applications are possible without departing from the gist of the present invention.

(Third Embodiment) In the present embodiment,
A timing signal generation unit that is generated in association with the operation of the driving unit, and at least one of a pseudo timing signal generation unit that generates a pseudo timing signal,
The driving state of the vibration wave motor is finely adjusted by at least one of the timing signal and the pseudo timing signal.

FIG. 15 shows a main configuration of the present embodiment.

FIG. 17 shows an example of a circuit configuration for generating the pseudo BD signal GBD.

Independent vibration wave motors are used for drive control of a plurality of photosensitive drums, and toner images of each color formed on each photosensitive drum are sequentially transferred to a recording medium on a transfer belt 333 to form a color reproduced image. In such an image forming apparatus, the vibration wave motor 401 is used to drive the transfer belt 333. A drive roller (not shown) is connected to the vibration wave motor 401, and the rotation unevenness of the vibration wave motor 401 not only causes the transfer speed unevenness of the transfer belt, but also causes the unevenness of the transfer speed of the recording medium. Wear marks and scratches on the transfer belt cause problems such as poor image quality and increased component replacement costs. In addition, when starting, stopping, and changing the speed, problems such as wear marks have been a problem. Further, in the example of the second embodiment, the laser is turned on to finely adjust the speed of the vibration wave motor in a state where the BD signal is generated.
There has been a problem that the speed can be finely adjusted only at the signal cycle, and the speed cannot be finely adjusted flexibly. Furthermore, there is a problem that a BD signal cannot be generated unless the laser is turned on.

When the transfer speed of the transfer belt becomes uneven,
The transfer timing when the images are sequentially transferred at the transfer positions of the image forming units 317, 318, 319, and 320 varies, causing registration misregistration in which images of the respective colors are not accurately superimposed. In addition, when the transfer speed of the transfer belt varies in the transfer process at the transfer position of each color, the image expands and contracts, and the sub-scanning pitch of each line is not uniform.

Further, even when there is no uneven transfer speed of the transfer belt, if there is a speed difference between the rotation speed of the photosensitive drum and the transfer speed of the transfer belt, image expansion / contraction and registration deviation occur. Even when the speed difference has a speed difference unevenness, image deterioration such as color unevenness and density unevenness is caused.

Therefore, in the embodiment, in the drive control of the plurality of vibration wave motors, the drive of the plurality of vibration wave motors is performed by a timing signal generated in association with the operation of the driving means provided separately from the vibration wave motor. It is also characterized in that the state is finely adjusted and a plurality of vibration wave motors operate in cooperation with each other.

In FIG. 15, reference numeral 502 denotes an oscillator for generating a reference clock.
5, 506 are Y, M, C, K polygon mirror motors, and 507, 508, 509, 510 are Y, M, C,
BD detection means for detecting K laser scanning light;
Reference numeral 6 denotes a pseudo BD generation unit which includes 527, 528, 529,
Reference numeral 530 is a selector, which is 511, 512, 513, 5
Reference numeral 14 denotes a vibration wave driving device that drives the Y, M, C, and K photosensitive drums. Reference numeral 515 denotes a vibration wave motor that drives the transfer belt, and 516, 517, 518, 519, and 520.
Is an encoder for detecting the rotational speed of each vibration wave motor, and 521, 522, 523, 524, and 525 are control devices for controlling the drive of each vibration wave motor. Information such as the target speed is set by a CPU (Central Processing Unit) (not shown) before the operation is started.

In FIG. 17, reference numeral 601 denotes an up counter.
602 is a comparator. The count output up-counted by the clock is input to a comparator 602, and is used to determine a pseudo BD cycle sent from a CPU (not shown).
The data is compared with the BD data.
02, the comparison result GBD = High is output. When a BD signal selection signal BDSEL = Low from a CPU (not shown), the BD signal of each color is not selected, and the pseudo BD
A signal is selected and 511, 512, 5
13,514 are sent to the control device of the vibration wave motor of each color. Similarly, the output of the selector 530 for K color is input to the control circuit of the vibration wave motor of the transfer belt as a BD signal. In the present embodiment, the rotation of the K-color photosensitive drum and the rotation of the transfer belt are substantially synchronized, and control is performed so that the phase difference and the speed difference between the K-color BD signal and the encoder pulse are reduced. Although the density unevenness of the K color having the highest visibility is suppressed, it may be synchronized with a BD signal of another color.

The polygon mirror motor of each color is provided with an oscillator 5
PLL using the clock from O.02 as a common reference clock
Under the control, each polygon motor rotates so as to have the same speed at a predetermined rotation speed. The clock of the oscillator 502 is input as a common reference clock to the control device of each vibration wave motor.

[Activation of Vibration Wave Motors] When a plurality of vibration wave motors are started in cooperation with each other, the CPU (not shown) updates the target speed data while gradually increasing it, thereby increasing the rotation speed of each vibration wave motor. Let me do it. At this time, the GBD data for determining the pseudo BD cycle is: GBD data = (standard speed) * (standard BD cycle) /
(Target speed). That is, when a speed 1/10 of the standard speed is set as the target speed, GBD data that is 10 times the standard BD signal period is set in the comparator 602.
Next, 1/9, 1/8, 1/7,.
When the 1/1 speed is sequentially set as the target speed, the GBD data is nine times, eight times, and eight times the standard BD signal period.
.., 1 times are set in the comparator 602 correspondingly. The 1x GBD data is a count value corresponding to a cycle substantially equal to the main scanning cycle of the laser beam scanned by the polygon mirror motor. Therefore, while the phase difference and the speed difference of the encoder pulse between each vibration wave motor are reduced, the rotation speed of each vibration wave motor rises to a predetermined standard speed.

When each of the vibration wave motors reaches a predetermined speed, the CPU (not shown) controls the BD selection signal BDS.
EL = High is output and the selectors 527, 528, 5
At 29 and 530, the BD signal of each color from the BD detection means is selected, and the control means 51 of the vibration wave motor of the photosensitive drum of each color is selected.
1, 512, 513, and 514. The K-color BD signal is sent to the controller 515 for the transfer belt vibration wave motor, and the K-color photosensitive drum vibration wave motor and the transfer belt vibration wave motor are driven substantially in synchronization. .

When each of the vibration wave motors has reached a predetermined speed, if the polygon mirror motor has not reached the predetermined speed, or if the laser lighting state has not reached the predetermined usable state, the BD BD from detection means
Since the signal cannot generate a BD signal having a normal cycle, it is determined that a normal BD signal has been generated.
After confirming by the PU, the BD selection signal BDSEL = H
It is desirable to switch to high.

[Stopping the Vibration Wave Motor] When each vibration wave motor is stopped in cooperation with each other,
D selection signal BDSEL = Low is output, and the selector 52
At 7,528,529,530, the pseudo BD signal GBD from the pseudo BD generating means is selected.

When the vibration wave motors are stopped, the CPU (not shown) updates the target speed data while gradually reducing the data, thereby reducing the rotation speed of each vibration wave motor. At this time, the GBD data for determining the pseudo BD cycle is the standard speed 1
When a speed of / 1 is set as the target speed, GBD data that is one time the standard BD signal cycle is set in the comparator 602. Further, next, 1/1,..., 1/7, 1 of the standard speed
When the speeds of / 8, 1/9, and 1/10 are sequentially set as the target speeds, the GBD data is one time,..., Seven times, eight times, nine times, and ten times the standard BD signal period. Are set in the comparator 602 correspondingly. Therefore, while the phase difference and the speed difference of the encoder pulse between the vibration wave motors are reduced, the rotation speed of each vibration wave motor falls from the predetermined standard speed to the stop state. Of course, the GBD data is finer, 1.2 times, 1.5 times
.., May be set as follows.

By configuring as in the present embodiment, even if the polygon mirror motor has not started up to a predetermined rotation before starting each vibration wave motor, the pseudo BD
Since the BD speed difference control can be performed using the signal as an alternative BD signal, the start-up time of the image forming apparatus can be shortened, and the rotation unevenness of each vibration wave motor is eliminated, and the image quality is improved. be able to. Problems such as wear and scratches on the photosensitive drum and the transfer belt can be solved, and the life of each unit can be extended. Further, since the BD speed difference control can be performed without turning on the laser to generate the BD signal, it is unnecessary to irradiate the photosensitive drum with the laser beam. Also, without turning on the laser,
A pseudo BD signal having a period substantially the same as or different from the period of the normal BD signal and having an arbitrary period is defined as a BD signal.
Since the speed difference control can be performed, when starting, stopping, and shifting operations of the vibration wave motors, the speed difference between the vibration wave motors is minimized, and the vibration wave motors are operated cooperatively while being substantially synchronized with each other. A smooth speed change operation can be performed.

[At Abnormal BD Signal] For example, there is an abnormality in a laser element and a laser control circuit (not shown), an abnormality in rotation of the polygon mirror motor, and an abnormality in the BD signal from the BD detection means. In this case, a BD signal with a normal cycle is not generated. In such a case, the image forming apparatus generally has various kinds of abnormality detection means such as a laser operation abnormality detection means, a BD signal abnormality detection means, and an abnormal rotation detection of a polygon mirror motor. Various driving sources of the image forming apparatus are stopped by a CPU (not shown) based on the abnormality detection result. In such a case, since a BD signal in a normal BD cycle is not generated, it is difficult to stop each vibration wave motor without any speed difference. Therefore, problems such as wear of the photosensitive drum and the transfer belt have been caused.

In the present embodiment, when the various driving sources of the image forming apparatus are stopped by the CPU (not shown) based on the abnormality detection results of the various abnormality detecting means,
It is assumed that the BD selection signal BDSEL = Low. further,
The target speed data is updated while being gradually reduced by a CPU (not shown), and the rotation speed of each vibration wave motor is reduced. At this time, the GBD data for determining the pseudo BD cycle is set to be substantially the same as or different from the regular BD signal, and sequentially increased according to the target speed, so that the respective vibration wave motors are coordinated while being substantially synchronized. When stopping, the vibration wave motor can be stopped without causing a problem such as abrasion in a state where there is no speed difference between the photosensitive drum and the transfer belt.

[0216] The drive control of each vibration wave motor for driving the photosensitive drum includes encoder pulses generated with the rotation of each vibration wave motor and BD detection for detecting laser scanning light for raster-scanning each photosensitive drum. B detected by means
The control device of the vibration wave motor is controlled by the D signal or the pseudo BD signal so that the speed difference and the phase difference between the scanning speed and the rotation speed of the photosensitive drum are substantially zero for each color independently.

Here, the vibration wave motor 515 of the transfer belt
The K BD signal or the pseudo BD signal is input to the control device 525, and the transfer speed of the transfer belt is controlled so as to be equal to the rotation speed of the K photosensitive drum.

With this configuration, the speed difference between the transfer speed of the transfer belt and the rotation speed of the K photosensitive drum becomes substantially zero, and the image expansion and contraction of the most visually sensitive K color (black) toner image is performed. And the registration of the other color images with the K color image makes it possible to reproduce beautiful images without image deterioration such as registration deviation and density unevenness. As is well known, the registration of each color in the sub-scanning direction can be easily performed by adjusting the writing start timing of the image data.

Further, it goes without saying that the same effect can be obtained not only in the transfer belt means but also in the intermediate transfer means as described in this embodiment. Further, in the present embodiment, an image forming apparatus having a plurality of photosensitive drums has been described, but it is needless to say that the present invention can be applied to an image forming apparatus having one photosensitive drum. Further, the present invention can be applied to an image forming apparatus other than the laser exposure method.

[0220]

As described above, according to the vibration wave driving device of the present invention, when a vibration wave device such as a vibration wave motor is driven in cooperation with the driving of an electromagnetic motor, for example, the cooperative operation with the electromagnetic motor can be performed. When the vibration wave motor is driven alone
Alternatively, when the cooperative operation becomes inappropriate due to a trouble on the side of the electromagnetic motor or the output of the first signal or the like, the vibration wave device such as the vibration wave motor can be smoothly operated.

In particular, by using the second timing signal or the pseudo timing signal having substantially the same cycle as or different from the timing signal, the start, stop, and shift operations of the vibration wave device such as the vibration wave motor can be smoothly coordinated. It can be carried out.

In particular, in a laser scanning type image forming apparatus, the photosensitive drum as an image carrier is driven to rotate by a vibration wave device such as a vibration wave motor, so that the rotation unevenness of the photosensitive drum can be reduced.

Further, not only can the rotation of the driving means other than the vibration wave motor be precisely coordinated, but also the difference in the driving speed of the photosensitive drum and the transfer belt driven by the plurality of vibration wave motors can be eliminated, and the reproduced image can be reproduced. It is possible to reduce unevenness in line intervals, reduce wear of the photosensitive drum and the transfer belt, and prolong the life of the apparatus. It can be realized at a very low cost and with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a color image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a first embodiment of the present invention.

FIG. 3 is a graph showing frequency rotation speed characteristics of the vibration wave motor according to the first embodiment.

FIG. 4 is a configuration diagram of a second booster circuit.

FIG. 5 is a block diagram of the pulse generator of FIG. 2;

FIG. 6 is a block diagram of the speed detector of FIG. 2;

FIG. 7 is a diagram illustrating information of a frequency control memory according to the first embodiment.

FIG. 8 is a diagram illustrating information of a pulse width control memory according to the first embodiment.

FIG. 9 is a timing chart for explaining the timing of a BD signal and encoder pulses according to the first embodiment;

FIG. 10 is a schematic configuration diagram of a polygon mirror motor and BD signal detection means.

FIG. 11 is a circuit diagram of a photosensitive drum drive system and a polygon mirror motor drive system.

FIG. 12 is a timing chart showing the timing of the BD signal and the FG pulse of the polygon mirror motor.

FIG. 13 is an example of BD speed difference correction information stored in a BD speed difference correction memory 64;

FIG. 14 is a block circuit for correcting a BD speed difference according to the second embodiment;

FIG. 15 is a block circuit diagram for operating a plurality of vibration wave devices according to the third embodiment in a coordinated manner.

FIG. 16 is a main timing chart of the second embodiment.

FIG. 17 is a circuit diagram for generating a pseudo BD signal according to the third embodiment;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pulse generator 2 ... Boost means 3 ... Vibration wave motor 4 ... Encoder 5 ... Speed difference detector 6a ... Frequency control memory 6b ... Pulse width control memory 7a ... Frequency control adder 7b ... Pulse width control addition Unit 8 ... 10-bit down counter 9a, 9b ... 9-bit down counter 10 ... 10-bit equal comparator 11a, 11b ... RS flip-flop 12 ... Bit shift 13 ... Rise detection block 14 ... 8-bit down counter 15 ... Bit register

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) 9A001 F-term (Reference) 2C362 BA08 BA33 BA39 BA52 CA22 CA39 CB59 CB60 2H027 DA22 DA23 EA18 ED01 ED04 EE01 EE03 EE04 EF10 2H035 CG01 2H072 AB07 5H680 AA00 AA09 AA12 BB03 BC00 BC04 CC02 CC07 DD01 DD23 DD53 EE12 EE23 FF21 FF23 FF25 FF27 FF30 FF33 FF38 9A001 BB01 BB02 BB03 BB04 HH31 HH34 JJ35 KK15 KK31 KK29 KK29 KK29 KK29 KK29 KK29 KK29 KK29

Claims (44)

[Claims] 1. A vibration wave driving apparatus comprising: a plurality of driving means including a vibration wave device operating in cooperation with each other, and a drive control means for synchronously driving the vibration wave device with respect to one of the driving means in a cooperative relationship. The drive control means, based on a first signal generated each time a predetermined operation is performed by driving the one drive means, and a second signal representing a drive state of the vibration wave device, The first
A first control mode for driving and controlling the vibration wave device so that the second signal has a predetermined phase difference with respect to the signal of the first and second signals, and the vibration wave device based on the second signal and a target value. And a second control mode for performing drive control, wherein the second control mode is selected when synchronous driving of the vibration wave device with respect to the one driving means is not appropriate. 2. A vibration wave drive device comprising: a plurality of drive means including a vibration wave device operating in cooperation with each other, and a drive control means for synchronously driving the vibration wave device with respect to one of the drive means in a cooperative relationship. Wherein the drive control unit is configured to generate a first signal each time a predetermined operation is performed by driving the one drive unit, and a first signal generation unit that synchronizes with the first signal. A pseudo signal generation unit that generates pseudo signals having different periods, wherein the second signal is a predetermined signal with respect to the first signal based on a second signal indicating a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device so as to have a phase difference, and a second control mode for driving and controlling the vibration wave device based on the pseudo signal and the second signal. A vibration wave driving device characterized by the above-mentioned. 3. A vibration wave driving device having a plurality of driving means including a vibration wave device operating in cooperation with each other and having a drive control means for synchronously driving the vibration wave device with respect to one of the driving means in a cooperative relationship. Wherein the drive control means includes: a first signal generation unit that generates a first signal each time a predetermined operation is performed by driving the one drive means; and a substantially same cycle as the first signal or A pseudo signal generation unit that sequentially generates a plurality of pseudo signals having different periods, wherein the second signal is generated in response to the first signal based on a second signal indicating a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device so as to have a predetermined phase difference, and a second control mode for driving and controlling the vibration wave device based on the pseudo signal and the second signal. Vibration wave driving device characterized by having . 4. A vibration device comprising: a plurality of driving means including a plurality of vibration wave devices operating in cooperation with each other, and a drive control means for synchronously driving the vibration wave devices with respect to one of the driving means in a cooperative relationship. A wave driving device, wherein the drive control unit generates a first signal each time a predetermined operation is performed by driving the one drive unit; A pseudo-signal generation unit that generates pseudo-signals having the same period or different periods; and a second signal for the first signal based on a second signal indicating a driving state of the vibration wave device. A first control mode for driving and controlling the vibration wave device so as to have a predetermined phase difference, and a second control mode for driving and controlling the vibration wave device based on the pseudo signal and the second signal. And the first control mode and the Vibration wave driving apparatus is characterized in that the selectable by the second control mode and the selection means. 5. A vibration device comprising: a plurality of driving means including a plurality of vibration wave devices operating in cooperation with each other, and a drive control means for synchronously driving the vibration wave devices with respect to one of the driving means in a cooperative relationship. A wave driving device, wherein the drive control unit generates a first signal each time a predetermined operation is performed by driving the one drive unit; A pseudo-signal generation unit that sequentially generates a plurality of pseudo signals having the same cycle or different cycles, and based on a second signal indicating a driving state of the vibration wave device, the second signal is generated with respect to the first signal. A first control mode for driving and controlling the vibration wave device so that the two signals have a predetermined phase difference, and a second control mode for driving and controlling the vibration wave device based on the pseudo signal and the second signal. Control mode, wherein the first control Vibration wave driving apparatus characterized by a selectable by chromatography De and the second control mode and the selection means. 6. The vibration wave driving device according to claim 2, wherein the selection unit selects a second control mode when the vibration wave device is started. 7. The vibration wave driving device according to claim 2, wherein said selection means selects a second control mode when said vibration wave device is stopped. 8. The apparatus according to claim 2, wherein said selecting means selects said second control mode when an output state of said first signal is abnormal. Vibration wave drive. 9. The vibration wave driving device according to claim 2, wherein the selection unit is selected according to a non-driving body driven by the vibration wave motor. 10. The vibration wave driving device according to claim 1, wherein said one driving means is an electromagnetic motor. 11. The vibration wave driving device according to claim 1, wherein the vibration wave device is a vibration wave motor. 12. A vibration wave device that obtains a driving force by exciting a driving wave by applying a frequency signal to an electro-mechanical energy conversion element to operate in cooperation with another driving means. A vibration wave driving device that performs drive control, a rotation detection unit that detects a rotation state of the vibration wave device,
A timing signal generating unit that is generated in association with the operation of the driving unit, and a pseudo timing signal generating unit that generates a pseudo timing signal, according to one of the timing signal and the pseudo timing signal, A vibration wave driving device, wherein a driving state of the vibration wave device is finely adjusted. 13. An oscillatory wave device that obtains a driving force by exciting a driving wave by applying a frequency signal to an electro-mechanical energy conversion element to operate in cooperation with another driving means. A vibration wave driving device that performs drive control, a rotation detection unit that detects a rotation state of the vibration wave device,
A driving state of at least one or more of the vibration wave devices is controlled by a timing signal generating unit generated in association with the operation of the driving unit and a second timing signal different from a cycle generated based on the timing signal. A vibration wave driving device characterized in that it is finely adjusted. 14. One or a plurality of vibration wave devices for obtaining a driving force by exciting a driving wave by applying a frequency signal to an electro-mechanical energy conversion element and cooperating with one or more other driving means. A vibration wave driving device that drives and controls the vibration wave device to operate, and a rotation detection unit that detects a rotation state of the vibration wave device,
A timing signal generating unit that is generated in association with the operation of the driving unit, and a pseudo timing signal generating unit that generates a pseudo timing signal, and any one of the timing signal and the pseudo timing signal,
A first mode for finely adjusting the driving state of the vibration wave device;
A second mode in which a driving state of the vibration wave device by at least one of the timing signal and the pseudo timing signal is not finely adjusted. 15. The vibration wave driving device according to claim 12, wherein the vibration wave driving device has a mode in which at least one of the timing signal and the pseudo timing signal is deactivated. 16. A mode in which an adjustment amount for finely adjusting a driving state of at least one or more vibration wave devices is changed according to at least one of the timing signal and the pseudo timing signal. Item 15. The vibration wave driving device according to item 12 or 14. 17. An adjustment amount for finely adjusting a driving state of at least one or more of the vibration wave devices can be nonvolatile memory means or rewritable at any time by at least one of the timing signal and the pseudo timing signal. 15. The vibration wave driving device according to claim 12, wherein the vibration wave driving device is constituted by a memory means or a register means. 18. The method according to claim 18, wherein at least two or more of the driving sources perform a speed changing operation in cooperation with the use of the vibration wave device and the driving means when at least starting, stopping, and changing the speed of the driving sources. Claim 12 or 14
6. The vibration wave driving device according to item 1. 19. The vibration wave according to claim 12, further comprising a timing signal selecting unit that selects one of the timing signal and the pseudo timing signal and sets the selected timing signal as a second timing signal. Drive. 20. A driving state of the vibration wave device is determined by a second timing signal selected by the selection unit and a rotation detection signal from a rotation detection unit that detects a rotation state of the vibration wave device. 20. The vibration wave driving device according to claim 19, wherein the vibration wave driving device is controlled. 21. Based on a phase difference or a speed difference between at least one of the timing signal and the pseudo timing signal and the rotation detection signal,
The driving state of the vibration wave device is controlled, wherein the driving state of the vibration wave device is controlled.
The vibration wave driving device according to 0. 22. A timing used for speed control according to a target speed of the various timing signals when at least starting, stopping, and changing the speed of these driving sources using the vibration wave device and the driving unit. 15. A signal is selectable, and at least two or more drive sources perform a speed change operation in a coordinated manner.
6. The vibration wave driving device according to item 1. 23. The vibration wave driving device according to claim 12, wherein a target value of the rotation speed of the vibration wave device is finely adjusted by the timing signal. 24. The vibration wave device according to claim 12, wherein the vibration body in which the vibration wave is excited and the contact body in press contact with the vibration body make a relative movement.
6. The vibration wave driving device according to item 1. 25. The vibration wave driving device according to claim 12, wherein the rotation detecting means is a speed detecting means for detecting a rotation speed of the vibration wave device. 26. The vibration wave driving device according to claim 25, wherein the rotation detecting means is a rotary encoder that detects a rotation amount of an output shaft of the vibration wave device. 27. The apparatus according to claim 12, wherein the rotation of the vibration wave device is controlled such that the timing signal and the rotation detection signal from the rotation detection means rotate substantially in synchronization. 15. The vibration wave driving device according to 13 or 14. 28. The driving state of the vibration wave device is finely adjusted by a pseudo timing signal until the rotation speed of the vibration wave device reaches a substantially predetermined rotation speed, and thereafter by the timing signal. Claims 12 to 27
The vibration wave driving device according to any one of the above. 29. The apparatus according to claim 12, further comprising data correction means for correcting speed difference information obtained from at least one of the timing signal and the pseudo timing signal and the rotation detection signal. The vibration wave driving device as described in the above. 30. The vibration wave driving device according to claim 29, wherein said data correction means is storage means for storing correction information. 31. The vibration wave driving device according to claim 30, wherein said data correction means is configured to select and use one of a plurality of correction data groups. 32. The vibration according to claim 12, wherein the fine adjustment control of the driving state of the vibration wave device by at least one of the pseudo timing signal and the timing signal can be deactivated. Wave drive. 33. An apparatus operation having the vibration wave driving device according to claim 1 and using the vibration wave device and the driving means as a driving source, and at least corresponding to a type of a recording medium. In order to change at least one of the image forming speed and various processing speeds in accordance with the operation of the device that brings a special effect to the reproduced image or the reproduced image, the speed of the vibration wave device and the driving unit is changed during normal image forming. An image forming apparatus wherein the speed is changed to a speed lower than or higher than the speed. 34. The apparatus according to claim 3, wherein said driving means is a polygon mirror motor of a laser beam scanning system.
4. The image forming apparatus according to 3. 35. The timing signal according to claim 34, wherein the timing signal is a timing signal generated at a timing substantially equal to a BD signal generated by a BD detection unit that generates a main scanning timing by laser beam scanning. Image forming apparatus. 36. The image forming apparatus according to claim 35, wherein the timing signal is a timing signal generated after a lapse of a predetermined time from a BD signal. 37. The image forming apparatus according to claim 35, wherein the timing signal is a timing signal obtained by counting a BD signal a predetermined number of times. 38. When a BD signal is not detected in a predetermined cycle, fine adjustment of a driving state of the vibration wave device is performed by using a prepared pseudo BD signal as the timing signal. Claims 35 and 3 characterized by the above-mentioned.
38. The vibration wave driving device according to 6 or 37. 39. The image processing apparatus according to claim 33, wherein a plurality of image carriers arranged in parallel along a transfer material conveying direction are driven by the vibration wave device.
9. The image forming apparatus according to any one of 8. 40. The apparatus according to claim 33, wherein a conveying means for conveying a transfer material to a transfer position with the image carrier is driven by the vibration wave device. Image forming device. 41. Intermediate transfer means for sequentially transferring images on the image carrier and holding the superimposed images, and conveying means for conveying a transfer material to a transfer position with the intermediate transfer means. 41. The image forming apparatus according to claim 33, wherein at least one of the intermediate transfer unit and the transport unit is driven by the vibration wave device. 42. A plurality of driving means including a vibration type motor are operated in cooperation with each other, and a driving means for synchronously driving another driving means with respect to a driving state of a predetermined one of the plurality of driving means. A reference signal forming unit for forming a first signal each time a predetermined operation is performed by driving the one driving unit in a device using a vibration type motor having a control unit as a driving source; and driving of the other driving unit. Speed detecting means for detecting a speed and forming a second signal having a cycle corresponding to the driving speed; and setting the speed of the other driving means to the target speed based on the second signal and target speed data. Speed control means for performing the correction in the speed control by the speed control means according to the phase difference between the first signal and the second signal, and performing the correction so that the phase difference becomes a predetermined phase difference. Controlled by speed control means Speed adjusting means for finely adjusting the driving speed of another driving means to be controlled, and prohibiting a correcting operation of the speed adjusting means according to a phase difference between the first signal and the second signal according to a driving condition of the apparatus. An apparatus using a vibration type motor as a drive source, characterized in that a prohibition means is provided. 43. The apparatus according to claim 42, wherein said prohibiting means prohibits operation of said speed adjusting means during a predetermined period of time or when the apparatus is stopped. . 44. The apparatus according to claim 44, further comprising: a pseudo signal forming means for forming a third signal having a period different from the first signal when the operation of the speed setting means is inhibited, In the above, the correction in the speed control by the speed control means in the speed control means is performed according to the phase difference between the third signal and the second signal, so that the phase difference becomes a predetermined phase difference. The apparatus according to claim 43, wherein the drive speed of another drive unit controlled by the speed control unit is finely adjusted.