JPH09182488A - Drive controller for image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a drive controller by which an irregularity in the density of an output image and the generation of the deviation 6f a registration are prevented by a method wherein a rotating member is controlled with high accuracy without a need of a complicated operation. SOLUTION: A change-frequency decision part 24 which decides a dominant change frequency f1 on the basis of speed change data, on one rotation of a photoreceptor drum 2, stored in a speed-change storage part 23 is installed. A frequency-characteristic measuring part 25 which measures the frequency characteristic of a drive transmission system on the basis of speed change data to be output from a position/speed detection part 14 is installed. On the basis of the frequency characteristic and the change frequency f1 , a feed-forward command-signal generation part 26 generates a feed-forward command signal, and the drum 2 is controlled on the basis of the generated feed-forward instruction signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for an image forming apparatus for controlling the drive of a rotary member such as an image carrier or a transfer material conveying body, and more particularly, to a rotary member which can be raised without any troublesome work. The present invention relates to a drive control device for an image forming apparatus, which can be controlled with high accuracy to prevent density unevenness of an output image and registration deviation.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrostatic image forming process of a laser printer or a copying machine, an image carrier such as a photosensitive drum, a transfer drum, an intermediate transfer belt, or a transfer material such as a transfer belt. A rotary member such as a carrier is provided, and it is an important subject to suppress the position and speed fluctuations of the rotary member to prevent density unevenness on the output image and misregistration.

Therefore, as a drive control device for a conventional image forming apparatus, which suppresses such position and speed fluctuations of the rotating member, there is, for example, the one disclosed in Japanese Patent Application Laid-Open No. 3-1187796.

The drive control device of the image forming apparatus includes a stepping motor for rotating an image bearing member such as a photosensitive drum and a transfer drum, and a plurality of exciting windings of the stepping motor for switching and exciting in a predetermined order. Drive means for driving the stepping motor, storage means for storing the speed fluctuation data of the stepping motor obtained in advance, and the excitation switching time interval of the stepping motor in accordance with the speed fluctuation data stored in the storage means to have periodicity. Control means for controlling the driving means by varying the driving means.

In such a structure, when the image carrier is rotated to form an image, the control means changes the excitation switching time interval of the stepping motor to the periodicity according to the speed fluctuation data stored in the storage means. The speed fluctuation of the stepping motor is reduced by allowing it to change. Therefore, the rotation fluctuation of the image carrier due to the rotation fluctuation of the stepping motor is suppressed, and the uneven density of the output image and the deviation of the registration can be prevented.

Further, according to the drive control device of the image forming apparatus, a plurality of speed fluctuation data are stored in the storage means,
One of the speed fluctuation data can be selected to control the excitation switching time interval of the stepping motor. In this case, if one piece of speed fluctuation data that produces the best image is selected with reference to the output image, the rotation fluctuation of the image carrier is suppressed in the subsequent image formation, resulting in uneven density and registration of the output image. It is possible to prevent the deviation.

[0007]

However, according to the drive control device of the conventional image forming apparatus, since the drive means is controlled so as to correct the speed fluctuation of the stepping motor, it occurs in the image carrier. If the rotation fluctuation is caused by the speed fluctuation of the stepping motor, the rotation fluctuation of the image carrier can be improved, but it is based on other causes such as fluctuation based on the dynamic characteristics of the torque transmission means and the like. However, there is a problem that the fluctuation improving effect cannot be expected at all.

Further, when a plurality of speed fluctuation data are stored and one of the plurality of speed fluctuation data is selected to control the driving means of the stepping motor, the storage capacity is wasted, resulting in an increase in cost. . Further, since the speed variation data is selected by trial and error by repeating the experiment, the work efficiency is poor and the speed variation data cannot be easily reselected. For this reason, when the optimal point of the excitation switching time interval of the stepping motor moves due to wear of parts or environmental changes, and density unevenness or registration deviation occurs in the output image, the excitation switching time of the stepping motor It takes a lot of time and effort to reset the interval to a new optimum point.

Therefore, an object of the present invention is to enable the rotating member to be controlled with high accuracy without any troublesome work.
It is an object of the present invention to provide a drive control device of an image forming apparatus capable of preventing unevenness in the density of an output image and the occurrence of registration deviation.

[0010]

SUMMARY OF THE INVENTION In view of the above problems, the present invention makes it possible to control a rotating member with high accuracy without requiring any troublesome work, thereby causing density unevenness of an output image and registration deviation. In order to prevent the
Speed fluctuation storage means for storing speed fluctuation data representing rotation speed fluctuations, fluctuation frequency determination means for specifying a dominant fluctuation frequency from the speed fluctuation data stored in the speed fluctuation storage means, and a torque source to a rotating member. Up to the frequency response characteristic of the drive transmission system, and the response characteristic calculation means for calculating the response characteristic of the drive transmission system at the dominant variation frequency, the speed variation data stored in the speed variation storage means, and the response characteristic calculation The present invention provides a drive control device for an image forming apparatus, which is provided with a feedforward command signal generating means for generating a feedforward command signal based on the response characteristic of the drive transmission system calculated by the means.

The response characteristic calculation means calculates a response time delay of the drive transmission system at a variation frequency where the frequency characteristic of the drive transmission system is dominant as the response characteristic, and the feedforward command signal generation means is the speed variation storage means. It is preferable that the feedforward command signal be generated by advancing the phase of the speed fluctuation data stored in the above by the response time delay calculated by the response characteristic calculating means.

The response characteristic calculating means calculates the response time delay and the gain of the drive transmission system at the variation frequency where the frequency characteristic of the drive transmission system is dominant as the response characteristic, and the feedforward command signal generating means calculates the speed variation. The phase of the speed fluctuation data stored in the storage means is advanced by the response time delay calculated by the response characteristic calculation means, and the speed fluctuation data is multiplied by the negative reciprocal of the gain to generate the feedforward command signal. preferable.

It is preferable that the feedforward command signal generating means has a structure for executing the generation of the feedforward command signal once immediately after the power is turned on.

It is preferable that the feedforward command signal generating means is configured to execute the generation of the feedforward command signal when the speed fluctuation of the rotating member becomes larger than a predetermined value.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A drive control device for an image forming apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the arrangement of an image forming apparatus according to the first embodiment of the present invention. This image forming apparatus includes a laser light source that emits laser light modulated based on image data, a laser light scanning unit 1 having a rotating polygon mirror that deflects the laser light, and the like while receiving exposure to the laser light. A photoconductor drum 2 that rotates in the sub-scanning direction to form an electrostatic latent image, a charger 3 that charges the photoconductor drum 2, and a developing device that develops the electrostatic latent image formed on the photoconductor drum 2 with toner. 4 and a motor 5 that generates rotational torque
And the rotational torque generated from the motor 5 to the photosensitive drum 2
To a transfer point of the photoconductor drum 2 by feeding the recording paper 9 with a torque transmission mechanism 6 for transmitting to the motor, a rotary encoder 7 for outputting a pulse signal having a cycle corresponding to the position or speed of the photoconductor drum 2. The paper feeding device 8, the transfer device 10 for transferring the toner image on the photosensitive drum 2 to the recording paper 9 guided to the transfer point, the fixing device 11 for fixing the transfer image on the recording paper 9, and the transfer image fixing A discharge tray 12 for discharging the completed recording paper is provided, and the photoconductor drum 2, the charging device 3, the developing device 4, and the transfer device 10 can be freely attached and detached as a process cartridge.

FIG. 2 shows the configuration of the drive control device of the image forming apparatus for controlling the drive of the photosensitive drum 2 in the first embodiment. The drive control device of the image forming apparatus includes a drive transmission system including a motor 5, a torque transmission mechanism 6, and a photosensitive drum 2, and a rotary that outputs a pulse signal having a cycle corresponding to the position or speed of the photosensitive drum 2. An encoder 7 and a position / speed detector 14 that detects the position and speed of the photosensitive drum 2 based on a pulse signal generated from the rotary encoder 7 to calculate speed fluctuations, and a reference position mark of the photosensitive drum 2. A reference position detection unit 16 that detects 15 and outputs a reference position signal, and a program in a setting mode is executed when the power switch is turned on to rotate the photoconductor drum 2 steadily and output from the position / speed detection unit 14. Speed fluctuation signal and reference position detector 16
Generates a feedforward command signal based on the reference position signal output from, and when the creation is completed, it shifts to the steady mode and executes the normal program to generate the feedforward command signal based on the feedforward command signal created in the setting mode. Control unit 17 for controlling drive circuit 18, and control unit 1
The drive circuit 18 outputs a drive signal according to the feedforward command signal output from the drive circuit 7 to drive the motor 5.

It is desirable that the motor 5 be driven at low cost and with high precision. For example, a DC brushless motor having a shaft with gear cutting processing or a stepping motor is used. When a stepping motor is used, in order to reduce fluctuations in rotation speed and power consumption, constant current driving is performed with a current value that is as small as possible while considering load torque.

The torque transmission mechanism 6 uses a reduction gear or a timing belt. As the reduction gear, for example, a helical gear made of polyacetal (POM) having good tooth contact and difficult to transmit torque fluctuation is used. On the other hand, as the timing belt, in order to ensure high precision drive by increasing the rotation fluctuation frequency generated by tooth contact, a belt with a pitch as small as possible is used in consideration of load torque. If the load torque is small,
If a steel belt is used instead of the timing belt, rotation fluctuation due to tooth contact is eliminated, so that more accurate driving can be realized.

When using the timing belt and the steel belt, a belt tensioner as shown in FIG. 3 is used. This belt tensioner has a frame 1
A base 13A fixed to 3 and a rod member 19A having a roller 19 at one end that rotates in contact with the belt 21;
A sliding mechanism portion 20 for slidably supporting the rod member 19A in the arrow direction on the base 13A;
An elastic member 22 is attached between the other end of A and the base 13A, and a predetermined tension is always applied to the belt 21 by elastic deformation of the elastic member 22.

Further, as means for generating a signal according to the rotation of the photosensitive drum 2, a tacho generator may be applied in addition to the rotary encoder 7.

As shown in FIG. 4, when the photosensitive drum 2 is steadily rotated in the setting mode, the control unit 17 uses the reference position signal output from the reference position detection unit 16 as the measurement start reference to determine the position / speed. A speed fluctuation storage unit 23 that stores speed fluctuation data for one rotation of the photoconductor drum 2 output from the detection unit 14, and the speed fluctuation data stored in the speed fluctuation storage unit 23 are frequency decomposed to obtain a dominant fluctuation frequency. The fluctuating frequency determining unit 24 for identifying f ₁ and the position / speed detecting unit 1 when the photosensitive drum 2 is steadily rotated in the setting mode.
4, the frequency characteristic measuring section 25 for measuring the frequency characteristic of the drive transmission system by inputting the speed variation data output from the reference numeral 4, and the frequency characteristic of the drive transmission system and the variation frequency determining section 24 measured by the frequency characteristic measuring section 25. The feedforward command signal generation unit 26 that generates the feedforward command signal based on the dominant fluctuation frequency f ₁ of the speed fluctuation data extracted in The feedforward command signal storage unit 27 that stores the feedforward command signal until the feedforward command signal is generated again in the next setting mode, and the feedforward command signal stored in the feedforward command signal storage unit 27 in the steady mode are read out and used as a reference. Based on the reference position signal output from the position detector 20, And a data conversion unit 29 that converts the signal input from the feedforward command signal transmission unit 28 and the frequency characteristic measurement unit 25 into a signal that the drive circuit 18 can receive. Has been done.

Feedforward command signal generator 26
Based on the dominant fluctuation frequency f ₁ of the speed variation data extracted by the frequency characteristic and the fluctuation frequency determination unit 24 of the measured drive transmission system at a frequency characteristic measuring unit 25, the dominant variation frequency f ₁ The response delay φ ₁ of the drive transmission system and the gain K ₁ are calculated. Then, the phase of the speed fluctuation data for one rotation of the photosensitive drum stored in the speed fluctuation storage unit 23 is set to the response delay φ of the drive transmission system at the fluctuation frequency f ₁ .
Advance by ₁ equivalent. Here, the response delay φ ₁ equivalent [s] can be calculated by the following equation (1).

[Equation 1] Then, the feedforward command signal is generated by multiplying the velocity fluctuation data advanced by the response delay φ ₁ in this way by the negative reciprocal of the gain K ₁ , that is, −1 / K ₁ .

Hereinafter, the drive control operation of the photosensitive drum 2 in the first embodiment will be described with reference to FIGS. 5 to 8.

First, when the power is turned on by the user or the like, the control unit 17 executes the program in the setting mode.
That is, the control unit 17 outputs a predetermined control signal to the drive circuit 18 to cause the drive circuit 18 to output a drive signal having a constant frequency or a current value, and drives the motor 5 at a constant speed. Rotate normally.

When the photoconductor drum 2 is steadily rotated, a pulse signal corresponding to the rotation of the photoconductor drum 2 is output from the rotary encoder 7, and the position / velocity detection unit 14 detects the position of the photoconductor drum 2 based on the pulse signal. , And the speed are detected to calculate the speed fluctuation of the photosensitive drum 2, and this is output to the control unit 17 as a speed fluctuation signal. Further, the reference position detector 16 detects the reference position mark on the photosensitive drum 2 and outputs a reference position signal to the controller 17.

In the control unit 17, the speed fluctuation storage unit 23 inputs the speed fluctuation signal with the reference position signal as an input start reference, and stores the speed fluctuation data for one rotation of the photosensitive drum 2 as shown in FIG. At the same time, the speed fluctuation data is output to the fluctuation frequency determination unit 24. Fluctuating frequency determination unit 24
Is 6 as shown in, by performing a frequency decomposition of the speed variation data to extract dominant variation frequency f _1, the variation frequency f ₁ of the data feedforward command signal generating unit 2
6 is output.

On the other hand, the frequency characteristic measuring unit 25 inputs the speed fluctuation signal output from the position / speed detecting unit 14, and the frequency characteristic of the drive transmission system as shown in FIG. 7, that is, the fluctuation frequency and the response characteristic ( The relationship between the gain and the phase) is measured, and this measurement data is output to the feedforward signal generator 26.

Feedforward command signal generator 26
The response delay phi ₁ and the gain of the drive transmission system in a dominant variation frequency f ₁ based on the fluctuation frequency f ₁ input frequency characteristic of the drive transmission system input from frequency characteristic measuring unit 25 from the fluctuation frequency determination unit 24 Calculate K ₁ . Then, the response delay φ ₁ equivalent is calculated based on the equation (1) described above, and as shown in (a) of FIG. 8, the speed of one rotation of the photosensitive drum stored in the speed fluctuation storage unit 23 is calculated. The phase of the fluctuation data is advanced by an amount corresponding to the response delay φ ₁ of the drive transmission system at the fluctuation frequency f ₁ . At this time, as shown in FIG. 8 (b), when the response delay phi ₁ equivalent data immediately after start of measurement is based on the measurement start time, but protrudes in the time-axis negative side, the response delay phi ₁ corresponds with the protruding Minute data is shown in Figure 8.
As shown in (c), it moves to the end of the speed fluctuation data.
Then, a feedforward command signal is generated by multiplying the velocity fluctuation data of FIG. 8A by the negative reciprocal of the gain K ₁ , that is, −1 / K ₁ .

The feedforward command signal generated by the feedforward command signal generation unit 26 is stored in the feedforward command signal storage unit 27, and the storage of this feedforward command signal ends the execution of the program in the setting mode.

On the other hand, in the steady mode, when the image formation command is received, the program in the steady mode is executed, and based on the feedforward command signal stored in the feedforward command signal storage unit 27, the drive circuit 18, that is, the photosensitive circuit. The drive of the body drum 2 is feedforward controlled. That is, when the image formation command is received, the feedforward command signal transmission unit 28 reads the feedforward command signal stored in the feedforward command signal storage unit 27, and the reference position signal output from the reference position detection unit 16 is read out. The data is sent to the data conversion unit 29 at a predetermined timing based on the above. The data converter 29 converts the input feedforward command signal into a signal that the drive circuit 18 can receive, and outputs this to the drive circuit 18 as a control signal.

When the drive circuit 18 inputs a control signal corresponding to the feedforward command signal stored in the feedforward command signal storage unit 27, the drive circuit 18 outputs a drive signal corresponding to the control signal to the motor 5, and the motor 5 , That is,
The photosensitive drum 2 is driven.

As described above, the speed fluctuation data of the photosensitive drum 2 is obtained by actual measurement in advance, and based on the speed fluctuation data, the feedforward considering the frequency characteristic of the drive transmission system, that is, the response characteristic at the frequency that is dominant in the speed fluctuation. Since the command signal is generated and the drive of the motor 5 is controlled, the speed fluctuation including the cause of the entire drive transmission system can be corrected, and the photosensitive drum 38 is controlled with high accuracy.
Rotational fluctuations of the photoconductor drum 38 can be suppressed.
Therefore, it is possible to obtain a high-quality image without unevenness in the output image or deviation in registration.

FIG. 9 shows the structure of a color copying machine 30 as an image forming apparatus according to the second embodiment of the present invention. The image forming apparatus includes an image sensor 33 that scans a document (not shown) placed on a platen 32 to read a document image, an image input unit 34 having a motor 31 that drives the image sensor 33, and an image input unit 34. And an image output unit 35 that forms an image on recording paper based on an image signal read by the image processing unit (not shown).

The image output section 35 emits a laser beam corresponding to image information and scans the photosensitive drum 38 via the reflection mirror 37, and a laser beam scanning unit 36, Y, M, and
A developing unit 39 that includes C and BK color toner units and supplies toner of a predetermined color to the surface of the photosensitive drum 38; a paper feed roll 41 that sends out recording paper 40;
A recording paper conveyance path 42 for conveying the recording paper 40, and the recording paper 40
To a transfer position at a predetermined timing, a suction charging device 44 that applies an electric charge to the recording paper 40, a conveyance drum 45 that holds and rotates the recording paper 40, and a transfer drum 45 transfer. A transfer charging device 46 provided at a position for applying a predetermined charge, a peeling charging device 47 for applying a charge for peeling the recording paper 40 from the transport drum 45, and a toner image transferred onto the recording paper 40 is fixed. The fixing unit 48, the discharge tray 49 for discharging the recording paper having the toner image fixed thereon, the cleaner 50 for removing the toner remaining on the photosensitive drum 38, and the charging for giving a predetermined charge to the photosensitive drum 38. Device 51, a motor 52 that generates a rotation torque according to the drive voltage, and a timing belt 53 that transmits the rotation torque generated by the motor 52 to the photosensitive drum 38. It has.

The timing belt 53 is selected with a pitch as small as possible in consideration of the load torque.
If the load torque is small, a steel belt may be used. Further, the timing belt 53 and the steel belt are configured such that a predetermined tension is always applied by the belt tensioner shown in FIG. 3 described in the first embodiment.

In such an image forming apparatus, the drive controller described above generates a feedforward command signal in consideration of the frequency characteristic of the drive transmission system from the speed fluctuation data of the photosensitive drum 38, and the motor 52 is based on this.
By controlling the drive circuit of, it is possible to control the photoconductor drum 38 with high accuracy and suppress the rotation fluctuation of the photoconductor drum 38. Therefore, it is possible to form a high-quality color image in which there is no color unevenness in the output image and color registration deviation.

In the second embodiment, the control unit 17 is usually provided inside the front panel 54 of the color copying machine 30 as shown in FIG.
As shown in (b) of 0, when the color copying machine 30 is connected to the computer 55 which can be remotely controlled, the computer 55 can be made to have the above-mentioned function and substituted.

FIG. 11 shows the configuration of the drive control device of the image forming apparatus according to the third embodiment of the present invention. In this figure, the same parts as those in FIG. 2 are designated by the same reference numerals and symbols, and a duplicate description will be omitted.

The drive control device of this image forming apparatus is stretched around a drive roll 57 for inputting rotational torque from the motor 5 via the torque transmission mechanism 6 and driven rolls 58A to 58C, and recording is performed by rotation of the drive roll 57. The recording paper transport belt 56 that transports the paper to the transfer unit and the fixing unit is configured to perform feedforward control.

Also in the drive control device of this image forming apparatus, a feedforward command signal considering the frequency characteristic of the drive transmission system is generated from the speed fluctuation data of the drive roll 57, and the drive circuit of the motor 5 is controlled based on this signal. By doing so, the recording paper conveyance belt 56 can be controlled with high accuracy, and the rotational fluctuation of the recording paper conveyance belt 56 can be suppressed.

In the third embodiment, the pulse generating means for generating the pulse signal having the pulse period corresponding to the position and speed of the recording paper conveying belt 56 is constituted by the rotary encoder. As shown, the marks 59 may be formed at equal intervals on the end of the recording paper conveyance belt 56, and a mark detector 60 including a light emitting element and a light receiving element for detecting the marks 59.
In such a configuration, since the movement of the recording paper conveyance belt 56 is directly detected, more accurate drive control can be realized. The mark detector 60 may be composed of a line image sensor.

FIG. 13 shows the arrangement of an image forming apparatus according to the fifth embodiment of the present invention. The image forming apparatus according to this embodiment receives a rotational torque from a motor 61 and is driven to supply a recording paper in a direction indicated by an arrow 62.
A recording paper conveyance belt 64 for driving the recording paper supplied from the supply roll 62 by receiving rotational torque from the motor 63, a suction device 65 for adsorbing the recording paper to the recording paper conveyance belt 64, and a motor 66A. To 66D through the torque transmission mechanisms 67A to 67D.
8A to 68D and a laser beam scanning unit 69 for exposing the photosensitive drums 68A to 68D to form an electrostatic latent image on the surface.
A to 69D and Y, M, C, and BK developing machines 70A to 7 for developing the electrostatic latent images on the photosensitive drums 68A to 68D by toner.
0D, transfer rolls 71A to 71D that transfer the toner images of the respective colors formed on the photoconductor drums 68A to 68D onto the recording paper conveyed through the recording paper conveyance belt 64, and the transfer rollers 71A to 71D before the electrostatic latent image formation. It comprises chargers 72A to 72D for charging the body drums 68A to 68D, and a fixing roll 73 for fixing the transfer image of the recording paper on which the transfer of each color is completed.

In such an image forming apparatus, the motor 63 for driving the recording paper carrying belt 64, Y, M, and
The motors 66A to 66D for driving the photoconductor drums 68A to 68D of C and BK are controlled based on the feedforward command signal generated by previously measuring the speed fluctuations of the steady rotations of these controlled objects by the drive control device described above. By doing so, the recording paper conveyance belt 64 and the respective photoconductor drums 68A to 68D can be controlled with high accuracy, and fluctuations in their rotations can be suppressed. Therefore, it is possible to form a high-quality color image in which there is no color unevenness in the output image or color registration deviation.

Further, as shown in FIG. 14, by applying the drive controller to the image forming apparatus using the intermediate transfer belt 74 driven by the motor 75, the motor 7
To prevent color unevenness of a color toner image and deviation of color registration when a color toner image is transferred by a secondary transfer roll 78 onto a recording sheet supplied to a secondary transfer point by a supply roll 77 rotated by 6. You can also

[0046]

As described above, according to the drive control device of the image forming apparatus of the present invention, the speed variation data of the rotating member is obtained, and the feed forward command signal in consideration of the response characteristic of the variation frequency of the drive transmission system is obtained. Since the rotating member is controlled based on the generated feedforward command signal, the rotating member can be controlled with high accuracy without any troublesome work, and the uneven density of the output image or the deviation of the registration can be achieved. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a drive control device according to the first embodiment.

FIG. 3 is an explanatory diagram showing a configuration of a belt tensioner according to the first embodiment.

FIG. 4 is an explanatory diagram showing a configuration of a control unit of the drive control device according to the first embodiment.

FIG. 5 is an explanatory diagram showing speed fluctuation data according to the first embodiment.

FIG. 6 is an explanatory diagram showing frequency characteristics of the drive transmission system in the first embodiment.

FIG. 7 is an explanatory diagram showing dominant fluctuation frequency components in the first embodiment.

FIG. 8 is an explanatory diagram showing a method of generating a feedforward command signal according to the first embodiment.

FIG. 9 is an explanatory view showing a second embodiment of the present invention.

FIG. 10 is an explanatory diagram showing an arrangement of a drive control device according to the second embodiment.

FIG. 11 is an explanatory diagram showing a third embodiment of the invention.

FIG. 12 is an explanatory diagram showing a fourth embodiment of the invention.

FIG. 13 is an explanatory diagram showing a fifth embodiment of the invention.

FIG. 14 is an explanatory diagram showing a sixth embodiment of the invention.

[Explanation of symbols]

 1 Laser Light Scanning Unit 2 Photosensitive Drum 3 Charging Device 4 Developing Machine 5 Motor 6 Torque Transmission Mechanism 7 Rotary Encoder 8 Paper Feeding Device 9 Recording Paper 10 Transfer Device 11 Fixing Device 12 Ejection Tray 13 Frame 13A Base 14 Position / Speed Detector 15 reference position mark 16 reference position detection unit 17 control unit 18 drive circuit 19 roller 19A rod member 20 sliding mechanism unit 21 belt 22 elastic member 23 speed fluctuation storage unit 24 fluctuation frequency determination unit 25 frequency characteristic measurement unit 26 feedforward command signal Generation unit 27 Feedforward command signal storage unit 28 Feedforward command signal transmission unit 29 Data conversion unit 30 Color copying machine 31 Motor 32 Platen 33 Image sensor 34 Image input unit 35 Image output unit 36 Laser light scanning unit 37 Reflection mirror 38 Photoreceptor Drum 39 Developing Unit 40 Recording Paper 41 Paper Feed Roll 42 Recording Paper Conveying Path 43 Registration Roll 44 Charging Charger 45 Conveying Drum 46 Transfer Charger 47 Peeling Charger 48 Fixing Unit 49 Paper Ejection Tray 50 Cleaner 51 Charger 52 Motor 53 Timing Belt 54 Front Panel 55 Computer 56 Recording Paper Conveying Belt 57 Drive Roll 58A to 58C Driven Roll 59 Mark 60 Mark Detector 61 Motor 62 Supply Roll 63 Motor 64 Recording Paper Conveying Belt 65 Adsorber 66A to 66D Motor 67A-67D Torque transmission mechanism 68A-68D Photoreceptor drum 69A-69D Laser light scanning unit 70A-70D Developing machine 71A-71D Transfer roll 72A-72D Charger 73 Fixing roll 74 Intermediate transfer Belt 75 motor 76 motor 77 supply roll 78 the secondary transfer roll

Claims (5)

[Claims] 1. A drive control device for an image forming apparatus, which controls drive means for driving a torque generating source for rotating a rotating member such as an image carrier and a transfer material conveying body based on a feedforward command signal. Speed fluctuation storage means for storing speed fluctuation data representing speed fluctuation of one rotation of a member in a steady state, and fluctuation frequency determination means for specifying a dominant fluctuation frequency from the speed fluctuation data stored in the speed fluctuation storage means. A response characteristic calculation means for obtaining a frequency response characteristic of a drive transmission system from the torque generation source to the rotating member, and calculating a response characteristic of the drive transmission system at the dominant variation frequency from the frequency response characteristic; Based on the speed variation data stored in the means and the response characteristic of the drive transmission system calculated by the response characteristic calculating means. Drive control unit of the image forming apparatus characterized by comprising a feed-forward command signal generating means for generating a over-forward command signal. 2. The response characteristic calculation means calculates a response time delay of the drive transmission system at the dominant fluctuation frequency of the frequency characteristic of the drive transmission system as the response characteristic, and the feedforward command signal generation means. The image according to claim 1, wherein the feedforward command signal is generated by advancing the phase of the speed fluctuation data stored in the speed fluctuation storage means by the response time delay calculated by the response characteristic calculation means. Drive control device for forming apparatus. 3. The response characteristic calculating means calculates, as the response characteristic, a response time delay and a gain of the drive transmission system at the dominant fluctuation frequency of the frequency characteristic of the drive transmission system, and the feedforward command signal. The generation means advances the phase of the speed fluctuation data stored in the speed fluctuation storage means by the response time delay calculated by the response characteristic calculation means, and adds a negative reciprocal of the gain to the speed fluctuation data. The drive control device for an image forming apparatus according to claim 1, wherein the feedforward command signal is generated by multiplying by. 4. The drive control apparatus for an image forming apparatus according to claim 1, wherein the feedforward command signal generating means is configured to execute the generation of the feedforward command signal once immediately after power is turned on. 5. The feedforward command signal generating means is configured to execute the generation of the feedforward command signal when the speed fluctuation of the rotary member becomes larger than a predetermined value. Drive control device for image forming apparatus.