JP4254339B2 - Motor drive control method, motor drive control device, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor drive control method, and more particularly to a motor drive control method and a motor control device provided in an image forming apparatus.
[0002]
[Prior art]
Usually, when a device is turned on, a current much larger than a steady-state current may flow instantaneously. This is called inrush current. Inrush current may exceed several times to several tens of times of steady state current, due to power switch welding, fuse blown, electrical stress on rectifiers and other components, and temporary drop in power supply voltage It may adversely affect other peripheral devices.
In order to cope with these problems, there are used methods that limit the inrush current by using components that can cope with the generated inrush current, or connecting resistors, power thermistors, switches, etc. to circuits and equipment. ing.
[0003]
Further, when driving a plurality of motors, it is known that an excessive inrush current is generated when power is supplied to the plurality of motors simultaneously.
The occurrence of inrush current may lead to malfunction of the protection relay and fuse, and the circuit may be damaged, so that multiple drive mechanisms such as rollers connected to the motor cannot be driven normally. The desired operation result may not be obtained.
Therefore, the power supply capacity must be increased in accordance with the inrush current, and the standard of the circuit element must be set to a standard product compatible with a large current, resulting in an increase in circuit cost.
[0004]
For example, in Patent Document 1, when the simultaneous activation of the compressor and the two motors is requested, the second activation current is prevented in order to prevent the activation current from temporarily increasing and the overload prevention relay from operating. A control device that delays the motor by 1 second from the first motor is disclosed.
[0005]
Patent Document 2 discloses two brushes for protecting a semiconductor element against an inrush current in a motor start-up operation and enabling a motor control circuit of a multipolar brush motor that can be handled by a low-current standard product. A motor control circuit is disclosed that energizes all brush circuits by delay means after energizing the circuit.
[0006]
[Patent Document 1]
JP 2002-34463 A
[Patent Document 2]
JP 11-98870 A
[0007]
[Problems to be solved by the invention]
However, the above document only discloses that the start timing is delayed in the inrush current generated at the start of the motor. Therefore, since the acceleration timing is not delayed at the time of motor acceleration after startup, an inrush current is generated even at the time of acceleration, and a large current is instantaneously applied to the power supply circuit, circuit elements, peripheral components and equipment. As a result, a plurality of drive mechanisms such as rollers connected to the motor are not driven normally, and a desired operation cannot be obtained, and the connected drive mechanisms may be damaged.
[0008]
An object of the present invention is to prevent superimposition of inrush current at the time of motor speed increase in motor drive control.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a motor drive control method for performing variable speed control on a plurality of motors, wherein the plurality of motors The acceleration delay time is set on the basis of the time until the inrush current generated at the time of speed increase returns to the current value at the normal load and the operation time that does not damage the image formation, and the acceleration delay time has elapsed. Adjusting the plurality of motors so as to sequentially increase the speed at a speed increase timing to It is characterized by.
[0010]
According to a second aspect of the present invention, in the motor drive control method for performing variable speed control on a plurality of motors, the plurality of motors. Start-up delay time and acceleration delay time are set based on the time until the inrush current generated at the time of start-up and speed-up returns to the current value at normal load and the operation time that does not damage the image formation, Adjusting the plurality of motors to sequentially start at the start timing at which the start delay time elapses, and to sequentially increase the speed at the speed increase timing at which the speed increase delay time elapses; It is characterized by.
[0011]
The invention according to claim 3 is the motor drive control method according to claim 1 or 2, The acceleration delay time or the startup delay time is: 50msec or more and less than 800msec Is It is characterized by that.
[0012]
According to a fourth aspect of the present invention, in the motor drive control method according to the first, second, or third aspect, the speed increase timing is adjusted for each motor.
[0013]
According to a fifth aspect of the present invention, in the motor drive control method according to the first, second, or third aspect, the adjustment of the acceleration timing is performed by dividing the plurality of motors into two or more groups and for each group. It is characterized by.
[0014]
According to a sixth aspect of the present invention, there is provided a motor drive control device that performs variable speed control on a plurality of motors. A storage unit that stores an acceleration delay time set based on a time until the inrush current returns to the current value at the normal load and an operation time that does not damage image formation, and the acceleration delay time elapses The multiple motors are sequentially increased at the acceleration timing. Control unit When, It is characterized by having.
[0015]
The invention according to claim 7 is a motor drive control device that performs variable speed control on a plurality of motors. A storage unit for storing a start delay time and an acceleration delay time set based on a time until the inrush current returns to a current value at normal load and an operation time that does not damage image formation; and the start delay time The plurality of motors are sequentially started at the start timing when elapses, and the plurality of motors are sequentially increased at the increase timing at which the acceleration delay time elapses. Control unit When, It is characterized by having.
[0016]
The invention according to claim 8 is the motor drive control device according to claim 6 or 7, The acceleration delay time or the startup delay time is: 50msec or more and less than 800msec Is It is characterized by that.
[0017]
According to a ninth aspect of the present invention, in the motor drive control device according to the sixth, seventh, or eighth aspect, the speed increase timing is adjusted for each motor.
[0018]
According to a tenth aspect of the present invention, in the motor drive control device according to the sixth, seventh, or eighth aspect, the adjustment of the acceleration timing is divided into two or more groups for the plurality of motors. It is characterized by being.
[0019]
The invention described in claim 11 is an image forming apparatus provided with the motor drive control device described in claim 6.
[0020]
A twelfth aspect of the present invention is an image forming apparatus including the motor drive control device according to the seventh aspect.
[0021]
A thirteenth aspect of the invention is an image forming apparatus including the motor drive control device according to the eighth aspect.
[0022]
The invention described in claim 14 is an image forming apparatus including the motor drive control device described in claim 9.
[0023]
A fifteenth aspect of the present invention is an image forming apparatus including the motor drive control device according to the tenth aspect.
[0024]
According to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the eleventh to fifteenth aspects, the plurality of motors are motors that drive the developing roller of the developing device.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described in connection with a plurality of developing motor drive control devices of a developing device in an image forming apparatus.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0026]
First, the configuration of the present embodiment will be described. FIG. 1 is a cross-sectional view showing an internal configuration of an image forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 includes an image reading unit 10 and a printing unit 20.
[0027]
The image reading unit 10 includes a scanner including a light source, a lens, a CCD (Charge Coupled Device), and the like. The image reading unit 10 forms an image of reflected light of the light irradiated on the document and photoelectrically converts the image to read and print the document image. To the unit 20. Here, the original image is not limited to image data such as graphics and photographs, but also includes text data such as characters and symbols.
[0028]
The printing unit 20 includes image forming units 30Y, 30M, 30C, and 30K, an intermediate transfer belt 50, a paper feeding unit 60, and a fixing unit 70.
[0029]
The image forming unit 30Y includes a photosensitive drum 31Y as a photosensitive member, a charging device 32Y, an exposure device 33Y, a developing device 34Y, and a cleaning device 35Y, and forms a yellow (Y) image.
[0030]
Specifically, the photosensitive drum 31Y charged by the charging device 32Y is irradiated with light by the exposure device 33Y to form an electrostatic latent image. The developing device 34Y develops the electrostatic latent image by attaching charged toner to the surface of the photosensitive drum 31Y on which the electrostatic latent image is formed. Further, after the toner attached to the surface of the photosensitive drum 31Y by the developing device 34Y is transferred to the intermediate transfer belt 50 described later, the cleaning device 35Y removes residual charges, residual toner, and the like on the surface of the photosensitive drum 31Y. To do.
[0031]
Similarly, the image forming unit 30M includes a photosensitive drum 31M, a charging device 32M, an exposure device 33M, a developing device 34M, and a cleaning device 35M, and forms a magenta (M) image.
[0032]
The image forming unit 30C includes a photosensitive drum 31C, a charging device 32C, an exposure device 33C, a developing device 34C, and a cleaning device 35C, and forms a cyan (C) image.
[0033]
Further, the image forming unit 30K includes a photosensitive drum 31K, a charging device 32K, an exposure device 33K, a developing device 34K, and a cleaning device 35K, and forms a black (K) image.
[0034]
The intermediate transfer belt 50 is rotatably supported by a plurality of rollers, and rotates as each roller rotates. The intermediate transfer belt 50 is pressed against the photosensitive drums 31Y, 31M, 31C, and 31K by primary transfer rollers 51Y, 51M, 51C, and 51K, respectively. As a result, the toner developed on the surfaces of the photoconductive drums 31Y, 31M, 31C, and 31K is transferred to the intermediate transfer belt 50 at the pressure-bonding positions by the primary transfer rollers 51Y, 51M, 51C, and 51K, and yellow, magenta, cyan, Each black toner is sequentially transferred in a superimposed manner.
[0035]
In the paper feeding unit 60, the recording paper P stored in the paper trays 61, 62, 63 is fed by the paper feeding unit 52, and passes through a plurality of intermediate rollers 53A, 53B, 53C, 53D, and a registration roller 54. It is conveyed to the next transfer roller 55. The toner image transferred to the intermediate transfer belt 50 is transferred onto the recording paper P surface by the secondary transfer roller 55. The recording paper P is heat-fixed by the fixing unit 70 on the toner image transferred to the recording paper P. The recording paper P that has been subjected to the fixing process is sandwiched between paper discharge rollers 56 and placed on a paper discharge tray 57.
[0036]
On the other hand, after the toner image is transferred to the recording paper P by the secondary transfer roller 55, the residual toner is removed by the cleaning unit 40 from the intermediate transfer belt 50 in which the recording paper P is separated from the curvature and electrostatically.
[0037]
FIG. 2 shows a cross-sectional view of the pair of image forming units 30.
The image forming unit 30 includes a photosensitive drum 31, a charging device 32, an exposure device 33, a developing device 34, and a cleaning device 35.
The photoconductive drum 31 is a photoconductive layer including a charge transport layer, which is coated on a metal cylindrical substrate with an organic semiconductor layer grounded, and is driven to rotate in the direction of an arrow.
The charging device 32 uniformly charges the periphery of the photosensitive drum 31 that is driven and rotated to a predetermined polarity and potential.
The exposure device 33 is a laser scanning type image exposure unit that emits a laser beam to scan and expose the uniformly charged surface of the photosensitive drum 31 to form an electrostatic latent image.
The developing device 34 develops the electrostatic latent image on the photosensitive drum 31 as a toner image. Development by contact or non-contact is performed by a combination of image exposure and reversal development.
[0038]
The developing device 34 mainly includes stirring and conveying screws 341a and 341b, a rotating paddle 342, a developing sleeve roller 343, a stripping roller 344, a collecting screw 345, an H-cut (heading restriction plate) 346, and the like.
[0039]
The toner is discharged to the rotating paddle 342 while being sufficiently mixed and stirred with the developer by the agitating and conveying screws 341a and 341b, and further stirred by the water wheel-like rotating paddle 342 and developed as a developer having an appropriate toner concentration and charge amount. It is supplied to the sleeve roller 343. The developer supplied to the developing sleeve roller 343 is regulated to an appropriate amount by the H-cut 346, contacts the photosensitive drum 31, and a visible image corresponding to the electrostatic latent image is formed. The developer on the developing sleeve roller 343 is once peeled off from the developing sleeve roller 343 by the peeling roller 344 and collected by the collecting screw 345 because the toner concentration is lowered, and stirred again so that the toner concentration becomes appropriate again. Is done.
[0040]
Since the developer is contained in the developing device 34, each roller and screw is driven to rotate for a long time, so that each roller and screw surface, each roller and screw shaft are moved by sliding with the developer and peripheral members. In addition to being consumed, the developer itself deteriorates.
[0041]
Each screw and roller in the developing device 34 is driven by one developing motor through a plurality of gears. The developing motor is connected to the outside of the developing device 34 via a plurality of gears, and all the screws and rollers in one developing device 34 are driven in an interlocking manner. The motor used for the developing motor is preferably a brushless motor or a stepping motor.
[0042]
Next, the image forming apparatus 1 having four sets of developing devices 34 will be described.
FIG. 3 is a schematic configuration diagram of the developing devices 34Y, 34M, 34C, and 34K and the developing motors MY, MM, MC, and MK mounted on the image forming apparatus 1.
As shown in FIG. 3, the drive circuits 90Y, 90M, 90C, and 90K drive the developing motors MY, MM, MC, and MK based on the signal from the control unit 100, and the gear unit GY that is configured by a plurality of gears. , GM, GC, and GK, the screws, rollers, and developing sleeve rollers 343Y, 343M, 343C, and 343K in the developing devices 34Y, 34M, 34C, and 34K are driven in conjunction with each other. Further, power is supplied from the power supply unit 200 to the developing motors MY, MM, MC, and MK.
The developing sleeve rollers 343Y, 343M, 343C, and 343K that are driven in conjunction cause toner to adhere to the surfaces of the photosensitive drums 31Y, 31M, 31C, and 31K.
[0043]
The control unit 100 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a storage unit, and the like, and stores programs and data stored in the ROM and the storage unit (not shown). The image forming apparatus 1 is expanded in a position storage area (not shown) such as a RAM, and various processes such as control of the entire image forming apparatus 1 and instructions to each unit are performed based on the program, and the image forming apparatus 1 is operated. In particular, in order to realize the present embodiment, the storage unit stores a Start / Stop signal for starting and stopping the developing motor M and a CLK signal for designating a speed at the time of shifting. In addition, when the motor is started and when the speed is increased, a start delay time A and an increase delay time B are stored in the storage unit as the time required until the next developing motor M is started and increased. A delay timer is provided for measuring whether the start delay time A and the acceleration delay time B of the development motor M have elapsed, and each of the development motors M is set so that the individual start and acceleration timings of the development motor M do not coincide with each other. Functions as an activation delay means and an acceleration delay means for shifting the activation and acceleration start timing.
[0044]
The control unit 100 may be a control unit unique to the developing device 34. The control unit 100 is connected to each unit in the image forming apparatus so as to be able to transmit and receive various information to and from each other, and receives information from each unit. The received information may be determined, information such as an operation instruction as a determination result may be output to each unit, and included in a control unit that controls each unit.
In the present invention, the control unit is not limited as long as it has such a property.
[0045]
The drive circuit units 90Y, 90M, 90C, and 90K detect the difference between the encoders that detect the rotation speeds of the developing motors MY, MM, MC, and MK and the command frequency based on the CLK signal from the control unit 100 to detect the developing motors MY, A drive control unit for correcting the rotational speeds of MM, MC, and MK is provided. The development motors MY, MM, MC, and MK are started and stopped based on the Start / Stop signal from the control unit 100, and the rotation speed, that is, the speed of the development motors MY, MM, MC, and MK is controlled based on the CLK signal. I do.
Further, the drive circuits 90Y, 90M, 90C, and 90K may be laid separately for the developing motors MY, MM, MC, and MK, or may be included in the control unit 100.
In the present invention, any driving circuit having such properties can be used without limitation.
[0046]
Although many motors are used in the image forming apparatus 1, the developing motors MY, MM, MC, and MK used in the developing devices 34Y, 34M, 34C, and 34K are required to have constant speed stability and the operation frequency. Therefore, it is preferable to use a brushless motor or a stepping motor.
[0047]
The development motors MY, MM, MC, and MK are subjected to start and stop control, speed increase and deceleration speed control by drive signals from the drive circuits 90Y, 90M, 90C, and 90K. In addition, driving power is transmitted to the plurality of screws and rollers in the developing devices 34Y, 34M, 34C, and 34K via the gear portions GY, GM, GC, and GK.
[0048]
The gear portions GY, GM, GC, and GK are configured by a plurality of gears and couplings, and a plurality of screws in the developing devices 34Y, 34M, 34C, and 34K are efficiently supplied with power from the developing motors MY, MM, MC, and MK. The plurality of screws and rollers in the developing devices 34Y, 34M, 34C, and 34K can be rotated by one developing motor MY, MM, MC, and MK.
[0049]
Since the photosensitive drums 31Y, 31M, 31C, and 31K are in contact with the intermediate transfer belt 50, the photosensitive drums 31Y, 31M, 31C, and 31K are preferably rotated at the same speed as the intermediate transfer belt 50, and at the same time It is preferable that the screws and rollers in the developing devices 34Y, 34M, 34C, and 34K connected to the drums 31Y, 31M, 31C, and 31K are also driven so as to follow, and the screws and rollers in the developing device are driven. It is preferable that the developing motors MY, MM, MC, and MK are simultaneously started and stopped, accelerated and decelerated.
[0050]
In order to suppress the deterioration of the developer described above, it has been devised that the rotation speeds of the developing motors MY, MM, MC, and MK are reduced until immediately before the electrostatic image is developed. If the motor is not started and stopped, accelerated and decelerated at the same time, it takes time to reach an appropriate rotational speed that does not cause a decrease in density or image omission, resulting in a problem that the first copy time is delayed. On the other hand, if the acceleration is started too early, the developer will be easily deteriorated by the impact of excessive stirring by the screw or roller in the developing device, and the cycle for replacing with a new developer will be shortened. As a result, the cost increases. Therefore, the development motors MY, MM, MC, and MK are preferably started and stopped, accelerated, and decelerated simultaneously.
[0051]
However, as described above, when starting and stopping, acceleration and deceleration are simultaneously performed, an inrush current is superimposed and a large inrush current is generated. Accordingly, the start delay time A and the acceleration delay time for shifting the start and acceleration timing of each developing motor based on the time until the inrush current returns to the current value at the normal load and the operation time that does not damage the image formation. B is set and stored in the storage unit in the control unit 100. Further, the activation delay time A and the acceleration delay time B are preferably 50 msec or more and less than 800 msec as a range that does not affect image formation, and the activation delay time A and the acceleration delay time B may be the same time, Different times may be used.
[0052]
Next, the operation of the present embodiment will be described.
As a premise of the operation description, a program for realizing each process described in the following flowchart is stored in a ROM or a storage unit in the form of a program code readable in the control unit 100 of the image forming apparatus 1. Thus, the control unit 100 sequentially executes operations according to the program code.
[0053]
FIG. 4 shows an operation flow when the developing motors MY, MM, MC, and MK are started in the image processing apparatus 1 executed by the control unit 100.
As shown in FIG. 4, when the developing motors MY, MM, MC, and MK are started (step S1: YES), the control unit 100 first sends a start / stop 1 signal as a start signal and a speed instruction to the drive circuit 90Y. The signal CLK1 is output. The drive circuit 90Y activates the developing motor MY based on the signal from the control unit 100 (step S2).
[0054]
A delay timer in the control unit 100 counts the activation delay time A, and determines whether the activation delay time A has elapsed after the development motor MY is activated. When the activation delay time A has elapsed (step 3: YES), the control unit 100 outputs the start / stop 2 signal as the activation signal and the CLK2 signal as the speed instruction signal to the drive circuit 90M. The drive circuit 90M activates the developing motor MM based on the signal from the control unit 100 (step S4).
[0055]
Subsequently, the delay timer in the control unit 100 measures the activation delay time A, and determines whether the activation delay time A has elapsed since the development motor MM was activated. When the activation delay time A has elapsed (step 5: YES), the control unit 100 outputs a Start / Stop3 signal that is an activation signal and a CLK3 signal that is a speed instruction signal to the drive circuit 90C. The drive circuit 90C activates the developing motor MC based on the signal from the control unit 100 (step S6).
[0056]
Further, the delay time in the control unit 100 counts the start delay time A, and determines whether the start delay time A has elapsed after the development motor MC is started. When the activation delay time A has elapsed (step 7: YES), the control unit 100 outputs the start / stop 4 signal as the activation signal and the CLK4 signal as the speed instruction signal to the drive circuit 90K. The drive circuit 90K activates the developing motor MK based on the signal from the control unit 100 (step S8).
[0057]
With this series of sequential start-up controls, it is no longer necessary to place an excessive current load on the motor drive circuit, power supply circuit, peripheral circuits, circuit elements, etc. due to inrush current.
[0058]
The order of activation is a preferred example of the motor drive control method, the motor drive apparatus, and the image forming apparatus 1 according to the present invention, and is not limited to this. For example, a plurality of developing motors may be divided into several groups and activated for each group, but this is not restrictive.
[0059]
Next, FIG. 5 shows an operation flow when the developing motors MY, MM, MC, and MK are accelerated in the image processing apparatus 1 executed by the control unit 100.
When the developing motor M is started and rotated at a speed required at the time of development during image formation for a long time, the developer deteriorates due to sliding in the developing device. A method of suppressing sliding by driving at a low speed has been devised. Accordingly, it is preferable to increase the developing motor M to a necessary speed only during image formation.
[0060]
As shown in FIG. 5, when the developing motors MY, MM, MC, and MK are accelerated (step S11: YES), the control unit 100 operates the operating frequencies of the CLK1, CLK2, CLK3, and CLK4 signals that are speed instruction signals. And a required speed signal is generated, and first, the CLK1 signal whose operating frequency is increased is output to the drive circuit 90Y. The drive circuit 90Y increases the speed of the developing motor MY based on the signal from the control unit 100 (step S12).
[0061]
An acceleration delay time B is counted by a delay timer in the control unit 100, and it is determined whether the acceleration delay time B has elapsed since the development motor MY is started. When the acceleration delay time B has elapsed (step 13: YES), the control unit 100 outputs the CLK2 signal with an increased operating frequency to the drive circuit 90M. The drive circuit 90M increases the speed of the developing motor MM based on the signal from the control unit 100 (step S14).
[0062]
Subsequently, the acceleration delay time B is measured by a delay timer in the control unit 100, and it is determined whether the acceleration delay time B has elapsed since the development motor MM was started. When the acceleration delay time B has elapsed (step 15: YES), the control unit 100 outputs the CLK3 signal with an increased operating frequency to the drive circuit 90C. The drive circuit 90C increases the speed of the developing motor MC based on the signal from the control unit 100 (step S16).
[0063]
Further, the acceleration delay time B is measured by a delay timer in the control unit 100, and it is determined whether the acceleration delay time B has elapsed since the development motor MC is started. When the acceleration delay time B has elapsed (step 17: YES), the control unit 100 outputs the CLK4 signal with an increased operating frequency to the drive circuit 90K. The drive circuit 90K increases the speed of the developing motor MK based on the signal from the control unit 100 (step S18).
[0064]
With this series of sequential speed increase control, it is no longer necessary to place an excessive current load on the motor drive circuit, power supply circuit, peripheral circuit, circuit element, and the like due to inrush current.
[0065]
Note that the speed increasing order is a preferred example of the motor drive control method, the motor drive device, and the image forming apparatus 1 according to the present invention, and is not limited to this. For example, a plurality of developing motors may be divided into several groups, and the speed may be increased for each group.
[0066]
FIG. 6 is a timing chart of control signals from the control unit 100 when starting and increasing the developing motors MY, MM, MC, and MK, and the speeds and elapsed times of the developing motors MY, MM, MC, and MK with respect to the elapsed time. The relationship of the electric current value supplied to a developing motor is shown.
[0067]
As shown in FIG. 6A, first, the control signal from the control unit 100 includes a Start / Stop1 signal that is an ON / OFF signal of the developing motor MY and a CLK1 signal that is a speed signal of the developing motor MY at t1. At the same time or the CLK1 signal rises first. The Start / Stop1 signal instructs the start-up of the developing motor MY by outputting High (1), and the CLK1 signal instructs the rotation speed of the developing motor MY by outputting a clock signal having a fixed period.
[0068]
Next, at the time t2 when the start delay time A has elapsed, the Start / Stop2 signal that is the ON / OFF signal of the developing motor MM and the CLK2 signal that is the speed signal of the developing motor MM rise, and the Start / Stop2 signal becomes High (1 ) Is output to instruct the start-up of the developing motor MM, and the CLK2 signal outputs the clock signal having the same constant cycle as MY to instruct the rotational speed of the developing motor MM.
[0069]
Further, at time t3 when the start delay time A has elapsed, the Start / Stop3 signal, which is the ON / OFF signal of the developing motor MM, and the CLK3 signal, which is the speed signal of the developing motor MC, rise, and the Start / Stop3 signal becomes High (1). Is output to instruct the start-up of the developing motor MC, and the CLK3 signal outputs the clock signal having the same constant cycle as MY and MM to instruct the rotational speed of the developing motor MC.
[0070]
Furthermore, at time t4 when the start delay time A has elapsed, the Start / Stop4 signal that is the ON / OFF signal of the developing motor MK and the CLK4 signal that is the speed signal of the developing motor MK rise, and the Start / Stop4 signal becomes High (1). Is output to instruct the start-up of the developing motor MK, and the CLK4 signal outputs a clock signal having the same constant cycle as MY, MM, and MC to instruct the rotation speed of the developing motor MK.
[0071]
At the time of acceleration, as shown in FIG. 6A, since the respective development motors MY, MM, MC, and MK are activated, the Start / Stop 1, 2, 3, and 4 signals are High. (1) is instructed. At the time of acceleration, first at t5, the CLK1 signal, which is the speed signal of the developing motor MY, outputs a clock signal having an operation cycle necessary for image formation. Next, at time t6 when the activation delay time B has elapsed, the CLK2 signal, which is the speed signal of the developing motor MM, outputs a clock signal having the same operation cycle necessary for image formation as the developing motor MY. Further, at time t7 when the activation delay time B has elapsed, the CLK3 signal, which is the speed signal of the developing motor MC, outputs a clock signal having the same operation cycle as that required for image formation as the developing motors MY and MM. Further, at time t8 when the start delay time B has elapsed, the CLK4 signal, which is the speed signal of the developing motor MK, outputs a clock signal having the same operation cycle as that required for image formation as the developing motors MY, MM, and MC.
[0072]
FIG. 6B shows a conceptual diagram of the driving speeds of the developing motors MY, MM, MC, and MK when the developing motors MY, MM, MC, and MK are started and accelerated.
As shown in FIG. 6B, first, at t1, the developing motor MY starts to be activated simultaneously with the Start / Stop1 signal and is rotated at a constant speed according to the CLK1 signal. Next, the development motor MM starts at the same time as the Start / Stop2 signal at t2 after the start delay time A has elapsed, and is rotated at a constant speed based on the CLK2 signal. Further, the developing motor MC starts at the same time as the Start / Stop3 signal at t3 after the start delay time A has elapsed, and is rotated at a constant speed based on the CLK3 signal. Further, after the activation delay time A has elapsed, the development motor MK starts activation simultaneously with the Start / Stop4 signal, and is rotated at a constant speed based on the CLK4 signal.
[0073]
At the time of acceleration, as shown in FIG. 6B, first, at t5, the developing motor MY is rotated at a speed based on the CLK1 signal. Next, the developing motor MM is rotated at a speed based on the CLK2 signal at t6 after the activation delay time B has elapsed. Further, the developing motor MC is rotated at a speed based on the CLK3 signal at t7 after the start delay time B has elapsed. Further, the developing motor MK is rotated at a speed based on the CLK4 signal at t8 after the activation delay time B has elapsed.
[0074]
FIG. 6C shows a conceptual schematic diagram of current value waveforms when the developing motors MY, MM, MC, and MK are started and accelerated. (1) indicated by a solid line is a current value waveform when the developing motor MY is started and accelerated alone. (2) indicated by a broken line is a combined current waveform when the developing motors MY and MM are started and increased at different starting and acceleration timings. (3) indicated by the alternate long and short dash line is a combined current waveform when the development motors MY, MM, and MC are started and speeded up by shifting the start timing and speedup timing. (4) indicated by a two-dot chain line is a combined current waveform when the development motors MY, MM, MC, and MK are started and increased at different start and acceleration timings.
[0075]
As shown in FIG. 6C, since the start-up timings of the developing motors are sequentially shifted so that the inrush currents multiplied by starting the developing motors are not combined at one time, the power supply circuit, circuit It is possible to prevent a large current from flowing instantaneously to the elements, peripheral components and equipment.
Similarly, even when the speed is increased, the acceleration timing of the developing motor is shifted and sequentially accelerated so that the inrush current multiplied by increasing the speed of each developing motor is not combined at one time. It is possible to prevent a large current from flowing instantaneously to peripheral components and equipment.
[0076]
In addition, the startup delay time and the acceleration delay time do not significantly affect the first copy time, and the inrush current generated and synthesized at the startup and acceleration of each developing motor is an allowable range of circuit elements, wiring, and power supply capacity. It is preferable that the range does not cause damage to image formation, and it is preferably 50 msec or more and less than 800 msec.
[0077]
Note that the description in the present embodiment described above is an example of a suitable motor drive control method, motor drive control apparatus, and image forming apparatus according to the present invention, and the present invention is not limited to this. Moreover, it is needless to say that changes can be made as appropriate without departing from the spirit of the present invention.
[0078]
【The invention's effect】
As described above, by adjusting the start timing of the developing motor and sequentially starting it, it is possible to prevent the inrush current from being superimposed at one time, and instantaneously in the power supply circuit, circuit elements, peripheral components and equipment. It is possible to prevent a large current from flowing. Similarly, by adjusting the acceleration timing of the development motor in order to accelerate it even during acceleration, it is possible to prevent the inrush current from being superimposed at once, and instantaneously apply to the power supply circuit, circuit elements, peripheral components and equipment. It is possible to prevent a large current from flowing through the.
Therefore, the power supply circuit, the circuit element, the peripheral component, and the device can be selected with an appropriate capacity without being influenced by the inrush current value of the superimposed large current, and the circuit cost and the device cost can be reduced. Can do.
In addition, by setting appropriate startup delay time and acceleration delay time, a desired image can be obtained without causing a large delay in the first copy time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an internal configuration of an image forming apparatus 1 according to an embodiment to which the present invention is applied.
FIG. 2 is a cross-sectional view showing an internal configuration of the image forming unit 30 shown in FIG.
3 is a schematic configuration diagram of a developing device 34 and a developing motor M in the image forming apparatus 1 shown in FIG.
FIG. 4 shows an operation flow when the developing motors MY, MM, MC, and MK are started by the control unit 100.
FIG. 5 shows an operation flow when the developing motors MY, MM, MC, and MK are accelerated by the control unit 100.
FIG. 6 shows the relationship between the activation and acceleration signals from the control unit 100, the speeds of the developing motors MY, MM, MC, and MK with respect to the elapsed time, and the current values of the developing motors MY, MM, MC, and MK with respect to the elapsed time. Show.
[Explanation of symbols]
1 Image forming device
10 Image reading unit
100 Control unit
200 Power supply unit
20 Print section
30 (Y, M, C, K) Image forming unit
31 (Y, M, C, K) Photosensitive drum
32 (Y, M, C, K) Charging device
33 (Y, M, C, K) Exposure equipment
34 (Y, M, C, K) Developing device
341 (a, b) stirring and conveying screw
342 Rotating paddle
343 (Y, M, C, K) Developing sleeve roller
344 Stripping roller
345 Recovery screw
346 H-cut part
35 (Y, M, C, K) Cleaning device
40 Cleaning section
50 Intermediate transfer belt
51 (Y, M, C, K) Primary transfer roller
52 Paper Feeder
53 (A, B, C, D) intermediate rollers
54 Registration Roller
55 Secondary transfer roller
56 Paper discharge roller
57 Discharge tray
60 Paper feeder
61, 62, 63 Paper tray
70 Fixing part
80 Cleaning section
90 (Y, M, C, K) Drive circuit section
G (Y, M, C, K) Gear section
M (Y, M, C, K) Development motor
P Recording paper
(1) Current of developing motor MY
(2) Composite current of development motors MY and MM
(3) Composite current of development motors MY, MM, MC
(4) Combined current of developing motors MY, MM, MC, MK

Claims (16)

In a motor drive control method for performing variable speed control on a plurality of motors,
The acceleration delay time is set based on the time until the inrush current generated at the acceleration of the plurality of motors returns to the current value at the normal load and the operation time that does not damage the image formation,
Adjusting the plurality of motors to sequentially increase at an acceleration timing at which the acceleration delay time elapses;
A motor drive control method characterized by the above. In a motor drive control method for performing variable speed control on a plurality of motors,
The start delay time and the acceleration delay time are set based on the time until the inrush current generated at the start-up and speed-up of the plurality of motors returns to the current value at the normal load and the operation time that does not damage the image formation. Has been
Adjusting the plurality of motors to sequentially start at the start timing at which the start delay time elapses, and to sequentially increase the speed at the speed increase timing at which the speed increase delay time elapses;
A motor drive control method characterized by the above. In the motor drive control method according to claim 1 or 2,
The speed increasing delay time or the start delay time, the motor drive control method which is a less than 50 msec 800 msec. In the motor drive control method according to claim 1, 2, or 3,
The motor drive control method characterized in that adjustment of the acceleration timing is performed for each motor. In the motor drive control method according to claim 1, 2, or 3,
The motor drive control method characterized in that the adjustment of the acceleration timing is performed for each group by dividing the plurality of motors into two or more groups. In a motor drive control device that performs variable speed control for a plurality of motors,
A storage unit for storing a speed-up delay time set based on a time until the inrush current returns to a current value at normal load and an operation time that does not damage image formation;
A controller that sequentially increases the speed of the plurality of motors at an acceleration timing at which the acceleration delay time elapses ;
A motor drive control device comprising: In a motor drive control device that performs variable speed control for a plurality of motors,
A storage unit for storing a start-up delay time and an acceleration delay time set based on the time until the inrush current returns to the current value at normal load and the operation time that does not damage image formation;
A controller that sequentially starts the plurality of motors at a start timing at which the start delay time elapses, and sequentially increases the speed at the plurality of motors at a speed increase timing at which the speed increase delay time elapses ;
A motor drive control device comprising: In the motor drive control device according to claim 6 or 7,
The speed increasing delay time or the start delay time, the motor drive control device which is a less than 50 msec 800 msec. The motor drive control device according to claim 6, 7 or 8,
The motor drive control device characterized in that adjustment of the speed increase timing is performed for each motor. The motor drive control device according to claim 6, 7 or 8,
The motor drive control device according to claim 1, wherein the adjustment of the acceleration timing is performed for each of the plurality of motors divided into two or more groups.   An image forming apparatus comprising the motor drive control device according to claim 6.   An image forming apparatus comprising the motor drive control device according to claim 7.   An image forming apparatus comprising the motor drive control device according to claim 8.   An image forming apparatus comprising the motor drive control device according to claim 9.   An image forming apparatus comprising the motor drive control device according to claim 10. The image forming apparatus according to any one of claims 11 to 15,
The image forming apparatus, wherein the plurality of motors are motors for driving a developing roller of the developing device.

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