JPH1042593A - Motor controller and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller which is capable of conducting optimum drive control of a group of motors whose controlling methods are different from each other, and provide an image-forming device using this controller. SOLUTION: An image-forming device, which forms images by transferring image data on sensitizing drums 342 to 345 onto a prescribed recording member by at least one transferring belt 333, is provided with an ultrasonic motor for rotationally-driving the sensitizing drums 342 to 345, a pulse motor for rotationally-driving the transferring belt 333 through a transferring belt roller 348, a plurality of driving control CPUs for controlling driving of both the motors by a different control method respectively, and an integrating control method which controls a plurality of driving control CPUs integrally and minimizes relative rotational speed of both the motors by synchronizing the operations at the rotating start and at the operating end of both the motors. It is thus possible to conduct optimum drive synchronizing control for both the motors whose control systems are different from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a motor control device for controlling the driving of a plurality of motors and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, a plurality of motors are rotated synchronously.
In a motor control device that needs to be stopped, a motor controlled by the same control method is usually used. For example, regarding a motor for driving a photosensitive member and a motor for driving a transfer member in an electrophotographic image forming apparatus, both motors are used not only during the transfer operation but also at the start and end of rotation (at the time of stop). Need to be rotated synchronously, but even in that case, synchronous control of both motors is relatively easy by using a motor controlled by the same control method.

However, on the other hand, especially in an electrophotographic image forming apparatus, it is required to use a motor having a higher rotational accuracy such as an ultrasonic motor as a transfer member driving motor in order to form a highly accurate image. Therefore, in a group of motors that need to perform synchronous rotation control for driving the transfer member and for driving the photosensitive member, a configuration using a plurality of types of motors having different control methods has been often adopted.

[0004] Here, the "ultrasonic motor" is a motor utilizing ultrasonic waves and vibrations proposed in Japanese Patent Application Laid-Open No. 58-14682.
9, JP-A-60-176470, JP-A-59-2044
The driving frequency, the driving voltage, and the pulse width of the driving voltage are controlled in accordance with a signal of a speed detecting means for stably rotating at a constant speed at 77 or the like.

[0005]

However, when the motor groups are controlled synchronously by the different control methods as described above, especially at the start and stop of rotation, the rise and fall characteristics of each motor are reduced. Due to the difference, the rotational speeds take different transitions (relative speeds are generated between the respective driving members), and finally, the state shifts to a state where synchronization cannot be achieved. The occurrence of such a relative speed between the drive members causes friction between the respective drive members, which often leads to wear and breakage of the drive members.

The present invention has been made in view of the above circumstances, and provides a motor control device capable of favorably controlling the drive of a motor group having a different control method, and an image forming apparatus using the control device. The purpose is to provide.

[0007]

According to the present invention, there is provided a motor control apparatus for controlling a plurality of motors, the plurality of motors being controlled by different control systems, and the plurality of motors being different from each other. A plurality of drive control means for performing drive control by a control method; and integrally controlling the plurality of drive control means, and synchronizing at least the rotation start operation and the end operation of the plurality of motors to thereby control the plurality of motors. And an integrated control means for minimizing the relative rotation speed of

According to another aspect of the present invention, there is provided an image forming apparatus for forming an image by transferring image information on at least one photosensitive member to a predetermined recording member using at least one transfer member. A plurality of motors controlled by different control methods to rotate the photosensitive member and the transfer member; a plurality of drive control means for controlling the driving of the plurality of motors by different control methods; and a plurality of drive control means And integrated control means for minimizing the relative rotation speed between the photosensitive member and the transfer member by synchronizing at least the rotation start operation and the end operation of the plurality of motors. And

[0009]

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

FIG. 1 is a configuration diagram showing a configuration of an image forming apparatus including a motor control device according to one embodiment of the present invention.

The image forming apparatus shown in FIG. 1 is composed of a color reader unit arranged at the upper part and a printer unit arranged at the lower part.

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

The color reader of the image forming apparatus mainly includes
A portion for reading a document, a CCD 101 mounted on a substrate 311, a platen glass (platen) 301 on which the document is placed, a document feeder (DF) 302, and a document by a halogen lamp or a fluorescent lamp. Light source 30 that illuminates
3 and 304; reflectors 305 and 306 for condensing the light from the light sources 303 and 304 on the original;
09, a lens 310 for condensing reflected light or projection light from the original on the CCD 101, and a CCD 101 shown in FIG.
And the binary conversion unit 201 and the delay unit 20 shown in FIG.
An image processing unit 312 including portions 2 to 205 and another IP
Interface (I / F) unit 313 to which U or the like can be connected
A carriage 314 that accommodates light sources 303 and 304, reflectors 305 and 306, and a mirror 307;
And a carriage 315 accommodating 8,309. Note that a mirror pressure plate may be mounted instead of the document feeder 302.

Here, the carriage 314 has a speed V
The carriage 315 scans the entire surface of the document (sub-scanning) by mechanically moving at a speed V / 2 in the direction perpendicular to the electrical scanning (main scanning) direction of the CCD 101. .

The CCD 101 converts an electric signal from an original placed on the original platen glass 301 and transmits the electric signal to the image processing unit 312. In addition, this CCD
In the case of a color sensor 101, a RGB color filter is inlined on a one-line CCD in the order of RGB, or a three-line CCD in which an R filter, a G filter, and a B filter are arranged for each CCD. It does not matter whether the filter is on-chip or the filter is configured differently from the CCD.

The image processing unit 312 includes a CCD 1
A predetermined image processing is performed on the signal from the control unit 01.

FIG. 2 is a block diagram showing a detailed configuration of the image processing unit 312.

As shown in FIG. 2, the image processing unit 31
2 is a clamp & Amp & S connected to the CCD 101
/ H & A / D section 102, this clamp & Amp & S / H
& Shading unit 10 connected to A / D unit 102
3. The tie connected to this shading part 103 &
MTF correction & original detection unit 104, input masking unit 1 connected to this connection & MTF correction & original detection unit 104
05, a selector 106 connected to the input masking unit 105, a color space compression & background removal & LOG conversion unit 107 connected to the selector 106, a background removal unit 115 connected to the selector 106, and a connection to the background removal unit 115 Black character determination unit 116, color space compression & background removal &
A delay unit 108 connected to the LOG conversion unit 107; a moire removing unit 109 connected to the delay unit 108 and the black character determination unit 116; a scaling unit 110 connected to the moiré removing unit 109; U connected to 110
CR & Masking & Black Character Reflection Unit 111, this UCR &
It has a γ correction unit 112 connected to the masking & black character reflection unit 111 and a filter unit 113 connected to the γ correction unit 112.

When an electric signal (analog image signal) from the CCD 101 is input to the image processing unit 312, the input signal is first sampled and held (S / H) by the clamp & Amp & S / H & A / D unit 102, The dark level of the analog image signal is clamped to the reference potential and further amplified to a predetermined amount (the processing order is not limited to the notation order),
It is A / D converted and converted into a digital signal of, for example, 8 bits for each of RGB.

Next, the RGB signals are subjected to shading correction and black correction in a shading section 103, and then to a connection & MTF correction & original detection section 104 in which
When the CD 101 is a three-line CCD, the splicing process differs in the reading position between the lines. Therefore, the delay amount for each line is adjusted according to the reading speed, and the signal timing is corrected so that the reading positions of the three lines become the same. In the MTF correction, the reading MTF changes depending on the reading speed and the magnification, so that the change is corrected, and the document detection recognizes the document size by scanning the document on the platen glass.

The digital signal whose read position timing has been corrected is input to the CCD 101 by the input masking unit 105.
And the light sources 303 and 304 and the reflector 305,
The spectral characteristics of 306 are corrected. The output of the input masking unit 105 is input to a selector 106 that can be switched with an external I / F signal.

The signal output from the selector 106 is input to a color space compression & background removal & LOG conversion unit 107 and a background removal unit 115.

After the signal input to the background removal unit 115 is removed from the background, the signal is input to a black character determination unit 116 which determines whether or not the document is a black character in the document, and a black character signal is generated from the document.

The color space compression / background removal / LOG conversion unit 107 to which the output of the other selector 106 is input.
Then, color space compression determines whether the read image signal is within the range that can be reproduced by the printer, and if so, corrects it so that the image signal is within the range that can be reproduced by the printer. . Then, a background removal process is performed, and the RGB signal is converted to M
Convert to CYK signal.

Then, the timing of the output signal of the color space compression / background removal / LOG converter 107 is adjusted by the delay unit 108 to correct the timing and the signal generated by the black character determination unit 116.

The two types of signals are subjected to moiré removal by the moiré removal unit 109 and are subjected to scaling processing in the main scanning direction by the scaling unit 110.

UCR & Masking & Black Character Reflection Unit 111
Generates a signal processed by the scaling unit 110 into an MCYK signal by UCR processing, corrects the signal to a signal output from the printer by a masking processing unit, and outputs a black character determination unit 116.
Is fed back to the MCYK signal.

This UCR & masking & black character reflection section 1
After the signal processed in 11 is subjected to density adjustment in the γ correction unit 112, the signal is subjected to smoothing or edge processing in the filter unit 113.

The signal processed as described above is shown in FIG.
Is converted from an 8-bit multi-level signal into a binary signal by the binary conversion unit 201. Note that this conversion method may be any of the dither method, the error diffusion method, and an improved error diffusion method.

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

The printer section is for recording the original image read by the color reader section on recording paper or the like.
As shown in FIG. 3, cassettes 340 for storing recording paper and the like,
341, pickup rollers 339 and 338, paper feed rollers 336 and 337, an adsorption charger 346 for charging the fed recording paper, and a transfer belt roller (transfer member) 3.
48 and a paper edge sensor 347 for detecting the edge of recording paper or the like.
M image forming unit 317, C image forming unit 318, Y image forming unit 319, and K image forming unit 320 for forming a toner image on the surface of recording paper or the like, transfer belt 333, charge removing charger 349, and peeling The charger 350 and the pre-fixing charger 35
1, 352, and a heat fixing unit 334 for heat fixing a toner image.
And a discharge tray 335 for discharging recording paper and the like.

Further, the M image forming unit 317 includes an LED.
A photosensitive drum (photosensitive member) 342 for forming a latent image on the surface thereof by light from an LED unit 210 such as an array, and a surface for charging the photosensitive drum 342 to a predetermined potential to prepare for a latent image formation. Unit 321 and photosensitive drum 342
A developing unit 32 for developing the latent image on the upper surface to form a toner image
2 and a transfer charger 323 that discharges from the back surface of the transfer belt 333 and transfers the toner image on the photosensitive drum 342 to recording paper or the like on the transfer belt 333.

The developing device 322 includes a sleeve 345 for applying a developing bias to develop. A temperature detection sensor 353 for detecting the temperature of the photosensitive drum 342 is provided inside the photosensitive drum 342, and is used to control the rotation operation of the drum (temperature detection sensors for the photosensitive drums 343, 344, and 345). 35
4,355,356 perform the same function. ). The method of controlling the rotation of the photosensitive drum 342 will be described later in detail.

In the above description, since the respective components of the M image forming section 317, the C image forming section 318, the Y image forming section 319, and the K image forming section 320 are almost the same, in this embodiment, M
The description mainly focuses on the image forming unit 317, and the description of the other image forming units is omitted. Further, in the apparatus of the present embodiment, since the transfer efficiency is high, the cleaner portion is not provided (however,
It goes without saying that there is no problem if the cleaner is installed.)

In the printer section, the cassette 34
The recording paper and the like stored in 0, 341 are fed one by one by feed rollers 336, 337 by pickup rollers 339, 338.
At the transfer belt 333. The fed recording paper is charged by the adsorption charger 346.

The transfer belt roller 348 drives the transfer belt 333, and charges the recording paper or the like in pairs with the attraction charger 346 so that the recording paper or the like is attracted to the transfer belt 333. I have.

The paper edge sensor 347 is connected to the transfer belt 333.
It detects the leading edge of the upper recording paper or the like. 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-scanning synchronization signal when a video signal is sent from the color reader unit to the printer unit.

In the image forming units 317 to 320, the recording paper or the like is conveyed by the transfer belt 333, whereby a toner image is formed on the surface of the recording paper or the like in the order of MCYK.

The static eliminator 349 includes a K image forming unit 320
In order to facilitate separation of the recording paper or the like that has passed through the transfer belt 333 from the transfer belt 333, static elimination is performed.

The peeling charger 350 is for preventing image disturbance due to peeling discharge when the recording paper or the like is separated from the transfer belt 333.

The recording paper and the like separated from the transfer belt 333 by the above-described units are charged by pre-fixing chargers 351 and 352 in order to supplement the toner attraction force and prevent image disturbance, and then fix the recording paper. After the toner image is heat-fixed at 334, the sheet is discharged onto a discharge tray 335.

The signal generated by the binary conversion unit 201 based on the paper leading edge signal from the paper leading edge sensor 347 is transmitted to the paper leading edge sensor 347 by the delay units 202 to 205 as shown in FIG. By adjusting the difference in distance from the image forming unit, four colors can be printed at predetermined positions. Further, the LED driving units 206 to 209 are L
A signal for driving the ED sections 210 to 213 is generated.

Here, in the present embodiment, the photosensitive drum 342
An ultrasonic motor is used as the drive motor for rotating the transfer belt roller 348, while a pulse motor is used as the drive motor for rotating the transfer belt roller 348.

The ultrasonic motor is a motor using an ultrasonic signal, and controls a driving frequency, a driving voltage, and a pulse width of the driving voltage in accordance with a signal of speed detecting means for rotating stably at a constant speed. Is what it is.

On the other hand, the pulse motor enables positioning of the motor by receiving a predetermined phase data signal. By periodically transmitting the phase data signal to the pulse motor, Rotating operation is realized. Note that this pulse motor is connected to the transfer belt roller 348.
Is rotated, so that the transfer belt 333 is also rotated.

The ultrasonic motor and the pulse motor have completely different structures and operating principles, and therefore, different control methods have been proposed. Hereinafter, a drive motor unit including a drive control unit for controlling each motor will be described.

First, a driving motor unit for rotating the transfer belt roller 348 will be described.

FIG. 4 is a block diagram showing the configuration of the pulse motor section 400 for rotating the transfer belt roller 348 (via the transfer belt roller 333).

The pulse motor unit 400 is controlled by a pulse motor control CPU 409, and includes a pulse motor 401, a phase data setting circuit 402, a phase data reading DMA 403, a phase pattern data storage memory 404, A data read cycle counter 405;
A clock 406, a phase data read cycle counter value read DMA 407, and a phase data read cycle counter value storage memory 408 are provided.

Here, the pulse motor 401 performs positioning according to the phase data by receiving the phase data set in the phase data setting circuit 402. The phase data for this positioning is set by transferring the phase data stored in the phase pattern data storage memory 404 by the data transfer operation by the DMA 403 for phase data reading.

FIG. 5 shows a phase pattern data storage memory 40.
4 shows an example of phase pattern data stored in No. 4. These data are positioning data for one rotation of the motor, and the rotation operation of the motor is realized by periodically transferring the data to the pulse motor 401. Further, the rotation speed of the motor can be set by changing the cycle of transferring the phase pattern to the pulse motor 401.

The phase data read cycle counter 405 subtracts the set phase data read cycle count value in synchronization with the input clock 406. When the phase data read cycle counter value becomes 0, the phase data read cycle counter value becomes zero. The data read DMA 403 is instructed to execute transfer. Therefore, the rotation speed of the pulse motor 401 can be changed according to the setting of the phase data read cycle count value.

The phase data read cycle counter value in the phase data read cycle counter 405 is the phase data read cycle counter value read DMA 407.
Thus, the cycle counter value stored in the phase data read cycle counter value storage memory 408 is set by being transferred. The instructions for making this setting are:
This is performed by instructing the phase data read cycle counter value read DMA 407 to execute transfer at the same timing as when the phase data read cycle counter 405 instructs the phase data read DMA 403 to execute transfer.

FIG. 6 shows an example of the phase data read cycle counter value data stored in the phase data read cycle counter value storage memory 408. The phase data read cycle counter value data is composed of three types of data: rotation start data T201, constant speed rotation data T202, and stop time data T203.

Next, a drive motor section for rotating the photosensitive drum 342 will be described.

FIG. 8 is a block diagram showing the structure of the ultrasonic motor unit 600 for rotating the photosensitive drum 342.

The ultrasonic motor section 600 is controlled by an ultrasonic motor control CPU 607, and includes an ultrasonic motor 601, a pulse width setting circuit 602, a frequency setting circuit 603, a speed control circuit 604, and a target speed setting section 60.
5.

The CPU for controlling the ultrasonic motor described above.
607 and the pulse motor control CPU 409 are connected via a DPRAM 1301 as shown in FIG. Thereby, the CPU 607 for controlling the ultrasonic motor,
Mutual communication with the pulse motor control CPU 409 is enabled, and integrated control of two motors described later is enabled.

Next, the operation of this embodiment will be described.

First, the control operation of the pulse motor 401 in the pulse motor section 400 will be described with reference to FIGS. FIG. 7 shows a rotation speed transition curve of the pulse motor 401.

The operation at the start of the rotation of the pulse motor 401 is based on the phase data read cycle counter value read DMA
This is performed by sequentially reading out the rotation start data T201 via 407 and continuing to set it in the phase data readout cycle counter 405. That is, the transition of the rotation speed of the motor at the start of rotation is determined by the cycle counter value in the rotation start data T201 as shown in FIG. Reference numeral 501 in FIG. 7 denotes rotation start data T201.
FIG. 6 shows a rotation speed transition curve at the time of a motor rotation start operation executed based on FIG.

Next, the operation of the pulse motor 401 at the time of constant speed rotation is performed by the phase data read cycle counter value read D
This is performed by repeatedly reading the constant-speed rotation data T202 via the MA 407 and continuing to set the phase data read cycle counter 405. That is, the rotation speed of the motor at the time of constant speed rotation is determined by the cycle counter value in the constant speed rotation data T202 as shown in FIG. In FIG. 7, reference numeral 502 denotes constant-speed rotation data T20.
2 shows a rotation speed transition curve at the time of a motor constant speed rotation operation executed based on No. 2.

When the pulse motor 401 is stopped, the operation of the phase data read cycle counter value read DMA
This is performed by sequentially reading out the constant-speed rotation data T <b> 203 via 407 and continuing to set the phase data readout cycle counter 405. That is, the transition of the rotation speed of the motor when the rotation is stopped is determined by the cycle counter value in the stop time data T203 as shown in FIG. Reference numeral 503 in FIG. 7 shows a rotation speed transition curve when the motor is stopped, which is executed based on the stop time data T203.

As described above, when the control method of the pulse motor 401 described in the present embodiment is used, the transition of the motor speed can be uniquely determined by the phase data read cycle counter value data. The above-described control processing of the pulse motor 401 is all executed by the pulse motor control CPU 409.

Next, the control operation of the ultrasonic motor 601 will be described with reference to FIG.

First, the rotation speed of the ultrasonic motor 601 is input to the speed control circuit 604 by the encoder 606.
Then, the encoder 6 controls the speed control circuit 604 to rotate at the rotation speed set by the target speed setting unit 605.
The frequency setting circuit 603 and the pulse width setting circuit 602 are controlled based on the number of rotations 06. As a result, the ultrasonic motor 601 is driven.

Here, there is a relationship shown by a curve graph as shown in FIG. 10 between the driving frequency and the rotation speed of the ultrasonic motor. This curve shows that as the temperature increases, FIG.
Has the characteristic of shifting in the direction indicated by the arrow. In addition, the same curve increases the drive pulse width (equivalent to increasing the voltage).
As a result, it moves in the direction indicated by the arrow in FIG.
In order to maintain a constant rotation speed against the previous temperature rise, the drive pulse width may be widened, but there is a limit to speed correction using only the pulse width. Becomes impossible.

In order to follow the speed, it is necessary to change the driving frequency. However, changing the driving frequency causes a change in the natural vibration characteristics of the motor, and consequently the deterioration of the copied image. Could lead to
Therefore, it is necessary to take care that correction by changing the drive frequency is not performed while the latent image is formed on the surface of the photosensitive drum.

As described above, the driving frequency of the ultrasonic motor for realizing the same rotation speed due to the difference in temperature is different. Therefore, the rotation speed transition curve at the start of rotation also fluctuates due to the temperature change. FIG. 11 shows the difference in the rotation speed transition curve at the start of rotation depending on the temperature. When the temperature increases, the driving frequency decreases, so that the time for following the constant speed increases, and the rotation speed transition curve changes toward 801. Conversely, when the temperature decreases, the drive frequency increases, so that the time for following the constant speed becomes shorter, and the rotation speed transition curve changes toward 802. On the other hand, it is known that the characteristics of the ultrasonic motor when stopped are very steep as shown in FIG. Note that all of the ultrasonic motor control processing described above is performed by the ultrasonic motor control CP.
This is executed by U607.

In the present image forming apparatus, the photosensitive drum 342 and the transfer belt 333 are completely in close contact.
Therefore, when a speed difference occurs between the photosensitive drum 342 and the transfer belt 333, there is a possibility that the members may be worn and damaged. Therefore, it is necessary to minimize the generation of the relative speed between the two members at the start of rotation and at the time of rotation stop, as well as during constant-speed rotation. That is, this means that it is necessary to control so as to suppress the generation of the relative speed between the ultrasonic motor and the pulse motor having different rotation characteristics and control methods.

To achieve this, the present image forming apparatus performs integrated control of both motors at the start and stop of rotation.

Next, the operation related to the integrated control will be described with reference to the flowcharts of FIGS.

FIG. 13 is a flowchart for explaining the integrated control of both motors at the start of rotation.

First, the photosensitive drum temperature sensors 353-3
The current photosensitive drum temperature information is obtained based on the sensor output 56 (S1001).

Next, a rotation speed transition curve at the start of rotation of the ultrasonic motor 601 for driving the photosensitive drums 342 to 345 is predicted based on the photosensitive drum temperature information obtained here (S1002). The temperature information of the photosensitive drum obtained in step S1001 is substantially the same as the temperature of the ultrasonic motor 601 for driving the photosensitive drum, and the rotation speed change at the start of rotation due to the temperature difference described in detail in FIG. It can be predicted by examining the change in the curve in advance. The processing in steps S1001 and S1002 is executed by the ultrasonic motor control CPU 607.

Next, the rotation speed transition curve information at the start of rotation predicted in step S1002 is transmitted from the ultrasonic motor control CPU 607 to the pulse motor control CPU 4.
09 (S1003). The ultrasonic motor control CPU 607 and the pulse motor control CPU 409 are configured as shown in FIG.
01 allows inter-CPU communication.

Next, the rotation start data T201 of the phase data read cycle counter value data is reset by the pulse motor control CPU 409 based on the rotation speed transition curve information obtained in step S1003 (S
1004). The transition of the speed at the start of rotation of the pulse motor 401 as a drive motor for rotating the transfer belt roller 348 can be uniquely determined based on the value of the rotation start data T201. Then, as a result, the pulse motor 401 for driving the transfer belt roller 348 can be rotated in synchronization with the speed change at the start of rotation of the ultrasonic motor 601 that changes according to the temperature.

Finally, a method of integrated control of both motors when rotation is stopped will be described with reference to the flowchart of FIG.

As described above, the characteristics when the ultrasonic motor 601 is stopped are very steep, so that the pulse motor 401 cannot follow the speed change when the ultrasonic motor 601 is stopped. Therefore, it is necessary to perform the following control.

First, the first target rotation speed is set in the target speed setting section 605 (S1101). Here, the first target rotation speed N ₁ is represented by the following relational expression N ₁ = (1-1) when the current rotation speed is N _max and the number of steps to 0 which is the final speed target speed is k. / K) × _Nmax . The setting of the target speed is performed by the ultrasonic motor control CPU 607.

Next, the stop time data T2 of the phase data read cycle counter value data of the pulse motor 401
03 is reset (S1102). The details of this processing will be described later.

Next, the operation of following the target speed of the ultrasonic motor 601 is performed by the control method described above (S1103).
However, in this case, it is expected that the difference between the target speed and the current speed is relatively large, and since the purpose is to finally stop the motor, it is assumed that the natural vibration characteristic of the motor has changed. Is not too much of a problem. Therefore, in S1102, only the correction of the driving frequency using the frequency setting circuit 603 is performed.

Subsequently, the arrival at the target speed using the encoder 606 is detected (S1104).

If the target speed 0 has been reached, that is, if the motor has stopped, all the processing ends.
If the target speed has been reached, the next target speed is set again (S1105). If the target speed has not yet been reached, the process of step S1103 is continued.

After reaching the target speed, step S1
When performing the setting of the new target speed N _m at 105, a new target speed N _m is calculated from the following equation based on the target speed N _m-1 previously set.

[0086] _{N m = N m-1 -} (N max / k) the step S11 after setting the new target speed again
The process after 03 is repeated.

By the stop control after step S1103, the ultrasonic motor 601 stops while showing a relatively gentle speed transition as shown in FIG.
The slope in this case differs depending on how the number of steps k up to the final speed target speed 0 is set.
Can be arbitrarily specified, and the speed transition curve at the time of stoppage of the ultrasonic motor 601 shown in FIG. 15 can be sufficiently predicted in advance. Therefore, in step S1102, in accordance with the expected speed transition curve, the pulse motor 4
The stop time data T203 of the phase data read cycle counter value data of 01 is reset. The setting of the stop time data T203 is performed by the pulse motor control CPU 409 acquiring a speed transition curve of the ultrasonic motor 601 predicted by communication with the ultrasonic motor control CPU 607, and performing the setting according to the curve. You.

By the above control, the pulse motor 401 serving as the transfer belt roller driving motor and the ultrasonic motor 601 serving as the photosensitive drum driving motor are synchronized, so that the transfer between the transfer belt and the photosensitive drum is performed. Smooth synchronization operation is realized. This makes it possible to minimize the possibility of wear and breakage of both members.

(Other Embodiments) The present invention is not limited to the above embodiments, and various modifications can be made.

For example, in the above-described embodiment, an image forming apparatus using a photosensitive and transfer system using a plurality of photosensitive drums and a transfer belt has been described. Of course, only a single photosensitive drum is used and a photosensitive drum is used in combination with a transfer drum. Alternatively, the present invention may be applied to an image forming apparatus that performs transfer.

In the above embodiment, the pulse motor 4
In the description above, two motors having different control methods, ie, a motor 01 and an ultrasonic motor 601, are used for driving the transfer belt roller and for driving the photosensitive drum, respectively. Alternatively, a motor controlled by a control method may be used. Further, it is of course possible to perform the same control for a group of motors other than the transfer belt roller driving motor and the photosensitive drum driving motor that need to be operated synchronously.

In the above description, when the two motors having different control methods, ie, the pulse motor 401 and the ultrasonic motor 601, are operated synchronously, the control is performed by a different integrated control method when the rotation is started and when the rotation is stopped. As described above, it is of course possible to perform integrated control at the start and stop of rotation by only one of the control methods.

In the above, the pulse motor control and the ultrasonic motor control are performed by different CPUs, and the integrated control is executed by communication between the two CPUs.
The configuration may be such that both CPUs are integrated into one CPU and the same control is performed by a single CPU.

[0094]

As described above, according to the present invention,
By taking into account the differences in the rotational characteristics of the motors with different control methods, the control means of each motor are integratedly controlled by higher-order integrated control means, so that the motors with different control methods are synchronized and drive-synchronized. As a result, generation of a relative speed between the motor and the rotating member can be prevented as much as possible.
As a result, the drive control of the motor groups having different control methods can be favorably performed, and, for example, abrasion and breakage of the rotating member can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an overall configuration of an image forming apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a detailed configuration of an image processing unit.

FIG. 3 is a block diagram showing a configuration of an LED part.

FIG. 4 is a block diagram illustrating a configuration of a pulse motor unit.

FIG. 5 is a diagram showing an example of phase pattern data used for pulse motor control.

FIG. 6 is a diagram showing an example of phase data read cycle counter value data used for pulse motor control.

FIG. 7 is a diagram showing a rotation speed transition curve during the rotation operation of the pulse motor.

FIG. 8 is a block diagram illustrating a configuration of an ultrasonic motor unit.

FIG. 9 is a diagram showing a communication configuration between a pulse motor control CPU and an ultrasonic motor control CPU.

FIG. 10 is a diagram illustrating a relationship between a driving frequency and a rotation speed in an ultrasonic motor.

FIG. 11 is a diagram showing a difference in a rotation speed transition curve at the start of rotation in the ultrasonic motor depending on temperature.

FIG. 12 is a diagram showing a rotation speed transition characteristic when rotation of the ultrasonic motor is stopped.

FIG. 13 is a flowchart showing an operation related to integrated control at the start of rotation of the pulse motor and the ultrasonic motor.

FIG. 14 is a flowchart illustrating an operation related to integrated control when the pulse motor and the ultrasonic motor are stopped.

FIG. 15 is a diagram showing a rotation speed transition curve of the ultrasonic motor at the time of stoppage when synchronous rotation with the pulse motor is performed.

[Explanation of symbols]

333 Transfer belt (transfer member) 342, 343, 344, 345 Photosensitive drum (photosensitive member) 401 Pulse motor 409 CPU for pulse motor control 601 Ultrasonic motor 607 CPU for ultrasonic motor control

Claims (8)

[Claims] A plurality of motors controlled by different control methods; a plurality of drive control means for driving and controlling the plurality of motors by different control methods; A motor control device, comprising: integrated control means for minimizing the relative rotation speed between the plurality of motors by synchronizing the rotation start operation and the end operation of the plurality of motors. 2. A plurality of motors controlled by different control systems to rotate a plurality of rotating members adjacent to each other, a plurality of drive control means for driving and controlling the plurality of motors by different control systems, Integrated control means for integrally controlling a plurality of drive control means and minimizing the relative rotation speed between the plurality of rotation moving members by synchronizing at least the rotation start operation and the end operation of the plurality of motors. A motor control device comprising: 3. At least one of the plurality of motors.
3. The motor control device according to claim 1, wherein the motor control device is an ultrasonic motor based on ultrasonic vibration control. 4. At least one of the plurality of motors
3. The motor control device according to claim 1, wherein one of the motor control devices is a pulse motor. 5. At least one of the plurality of motors
3. A DC motor according to claim 1, wherein:
The motor control device according to any one of the preceding claims. 6. An image forming apparatus for forming an image by transferring image information on at least one photosensitive member to a predetermined recording member by using at least one transfer member, wherein the image forming apparatus is controlled by a different control method, and A plurality of motors for rotationally moving the member and the transfer member; a plurality of drive control means for controlling the drive of each of the plurality of motors by different control methods; and an integrated control of the plurality of drive control means; An image forming apparatus comprising: an integrated control unit configured to minimize a relative rotation speed between the photosensitive member and the transfer member by synchronizing operations during a rotation start operation and an end operation. 7. An image forming apparatus according to claim 6, wherein said transfer member comprises a transfer drum, and said photosensitive member comprises a photosensitive drum. 8. The image forming apparatus according to claim 6, wherein said transfer member is constituted by a transfer belt, and said photosensitive member is constituted by a photosensitive drum.