JP2009251504A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for preventing a main motor from disproportionately having a large amount of rotation in particular by suppressing the useless rotation time of a motor for standby in a constant speed rotation state. <P>SOLUTION: A color printer 1 includes a plurality of motors and an output control part 61 for controlling the plurality of motors. The output control part 61 obtains the number of starting motors, according to the operation situation of an image forming part, sets an acceleration pattern for starting according to the obtained number of starting motors, and sets the acceleration pattern slower than the acceleration pattern set when the number of starting motors is small, when the number of starting motors is large, and performs the starting control of the starting motor of the plurality of motors alongside, according to the acceleration pattern and performs the constant speed control of the motor whose starting is completed of the plurality of motors. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copy, a printer, and a FAX. More specifically, the present invention relates to an image forming apparatus incorporating a plurality of motors for rotationally driving each member.

  The image forming apparatus has a plurality of rotating bodies such as a photoconductor and a developing roller. In many cases, a plurality of motors are provided to rotate them. For example, at the time of start-up by turning on the power, it is necessary to start some of the plurality of stopped motors and control them so as to obtain the required rotation speed. However, it is generally necessary to supply a larger current when starting up the motor than when performing constant speed control. Therefore, in order to be able to start multiple motors at the same time, it was necessary to provide a fairly large capacity power supply.

  In order to avoid providing a large-capacity power supply, conventionally, when starting up multiple motors, the startup timing has been shifted and started up in order. First, the first motor is activated, and the second motor is activated after a predetermined activation time has elapsed from the start of activation. Further, when the start-up time of the second motor has elapsed, it is determined that both motors are in a controllable state. For example, the maximum time required for starting the motor is set as the start time.

However, in this case, there is a problem that the waiting time from when the power is turned on until image formation can be started is long. On the other hand, there is disclosed an image forming apparatus that drives a polygon motor at a speed slower than a set speed until a predetermined suppression time elapses while simultaneously starting the main motor and the polygon motor. (For example, refer to Patent Document 1). According to the technique of this document, it is said that a large current is not required when starting the main motor and the polygon motor without increasing the waiting time.
JP 2007-225655 A

  However, in the control method in which each motor is started up in order as described above, the motor that is started up first is rotated at a constant speed after starting up at least during the start-up time set in the second motor each time it starts up. Wait in state. This set startup time is usually set to allow for a certain margin. In general, even if the rotation of the second motor is stabilized in a shorter time than the set time, both the motors wait in a constant speed rotation state until the start time elapses. Therefore, the earlier the motor is started, the longer the standby time in the constant speed rotation state, and the more the motor is rotated. This rotation during standby in the constant speed rotation state is a useless rotation that does not contribute to image formation.

  For example, the main motor is always started up for image formation under any conditions. In addition, when the main motor is started simultaneously with other motors, the main motor is generally started first. Then, as described above, the motor that is driven first waits in the constant speed rotation state after starting up until the other motor reaches the set speed. For this reason, the amount of accumulated rotation of the main motor is increased by the amount of wasted rotation compared to other motors, and therefore it has been desired to reduce the amount of wasted rotation as much as possible.

  Note that, even with the image forming apparatus disclosed in Patent Document 1, the main motor stands by at a constant speed until the rotation of the polygon motor is stabilized even after the suppression time has elapsed. Compared to the motor starting method based on the order, the waiting time in the constant speed rotation state is shortened, but the waiting time always occurs. For this reason, the cumulative rotational speed of the main motor is larger than the cumulative rotational speed of the polygon motor, and the difference is gradually accumulated.

  The present invention has been made to solve the problems of the conventional image forming apparatus described above. That is, an object of the present invention is to provide an image forming apparatus that suppresses a useless rotation time of a motor for standby in a constant-speed rotation state, and prevents an increase in the amount of rotation particularly due to the main motor. There is.

  An image forming apparatus of the present invention, which has been made for the purpose of solving this problem, includes an image forming unit that has a plurality of rotating bodies and forms an image by the rotation, and a plurality of motors that drive at least one of the plurality of rotating bodies. And a drive control unit that controls a plurality of motors, wherein the drive control unit includes a startup number acquisition unit that acquires the number of motors to be started according to the operation status of the image forming unit, and a startup number Acceleration pattern setting that sets the acceleration pattern for activation according to the number acquired by the acquisition unit and sets a gentle acceleration pattern when the number is large compared to the acceleration pattern set when the number is small And a startup control unit that controls startup of a plurality of motors in parallel according to the acceleration pattern set by the acceleration pattern setting unit and startup of the plurality of motors is completed. Those having a constant speed controller for constant speed control things.

  According to the image forming apparatus of the present invention, the number of motors to be activated is acquired by the activation number acquisition unit, and the acceleration pattern for the activation is set by the acceleration pattern setting unit. Further, the activated motors are activated in parallel by the activation control unit according to this acceleration pattern. In the present invention, this acceleration pattern is a gentler acceleration pattern than when the number is small, so that it is not necessary to provide a large power source even when starting in parallel. Furthermore, the timing of changing the control of each motor from the start control to the constant speed control can be close to each other as compared with the case where the controls are started sequentially one by one. Therefore, the waiting time in the constant speed rotation state of the specific motor does not increase. That is, the useless rotation time of the motor for standby in the constant speed rotation state is suppressed, and in particular, the amount of rotation is prevented from being biased toward the main motor.

In the present invention, the acceleration pattern set by the acceleration pattern setting unit when the number acquired by the activation number acquisition unit is plural is a stepped acceleration pattern that repeats an acceleration period and a non-acceleration period, and the activation control According to the step-like acceleration pattern, it is desirable that the unit sets a part of the motors to be started in an accelerated state and the remaining ones in a non-accelerated state, and sequentially replaces the motors in the accelerated state.
If this is the case, the motors that are simultaneously accelerated are some of the starting motors. In other words, there are always motors that are not accelerated. Therefore, compared with the case where all the motors are started simultaneously, the power supply amount can be made small. Further, the motors to be accelerated are sequentially replaced, and each is accelerated with a stepped acceleration pattern. Accordingly, acceleration is not biased toward a specific motor, and there is almost no waiting time in a constant speed rotation state of each motor.

Furthermore, in the present invention, it is desirable that the start control unit reduce the power supplied to the motor to be started when the number of motors to be started is large compared to the case where the number is small.
In this way, even if power is supplied to the motors that are started at the same time, the overall power supply does not become too large.

Furthermore, in the present invention, when there are a plurality of motors to be activated, it is desirable that the activation control unit starts the activation of each motor at a timing shifted from each other.
In this way, it is possible to prevent so-called inrush power from flowing simultaneously to the plurality of motors.

Furthermore, in the present invention, when there are a plurality of motors to be started, the start control unit is a value obtained by dividing the power supplied to each motor to be started by dividing the power supplied when the number of motors to be started is 1 by the number. Is desirable.
With such a configuration, it is possible to start each motor at the same time without increasing the time required to finish starting all the motors to be started.

  According to the image forming apparatus of the present invention, it is possible to suppress a useless rotation time of a motor for standby in a constant speed rotation state, and it is possible to prevent an increase in the amount of rotation particularly due to the main motor.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to an electrophotographic image forming apparatus.

  A schematic configuration of the color printer 1 of the present embodiment is shown in FIG. In this embodiment, the image cartridges 10Y, 10M, 10C, and 10K for each color are arranged along the intermediate transfer belt 11 so-called tandem type. The intermediate transfer belt 11 is spanned by three rollers 12, 13, and 14 and is driven to rotate. Each of the image cartridges 10Y, 10M, 10C, and 10K includes a photoconductor 15, a charger 16, and a developer 17. Further, an exposure unit 18 is provided below each of the image cartridges 10Y, 10M, 10C, and 10K. A polygon mirror 19 is disposed inside the exposure unit 18.

  Above the intermediate transfer belt 11 in FIG. 1, toner bottles 21Y, 21M, 21C, and 21K that store toners of the respective colors are arranged. Inside each of the toner bottles 21Y, 21M, 21C, and 21K, stirring blades 22 are provided for stirring the toner stored therein. A belt cleaner 23 is provided in contact with the left side of the intermediate transfer belt 11 in the drawing, and a waste toner box 24 is provided in the lower portion of the drawing.

  In addition, a sheet cassette 31 for storing sheets for image formation is disposed at the bottom of the color printer 1 in FIG. The paper stored in the paper cassette 31 is transported through a paper transport path 32 formed on the right side in the drawing. A paper feed roller 33, a timing roller 34, a secondary transfer roller 35, and a fixing device 36 are arranged in the paper conveyance path 32, and the paper is conveyed in order from the bottom to the top. Further, a paper discharge roller 37 is disposed at the top of the drawing, and the paper on which an image has been formed is discharged out of the apparatus by the paper discharge roller 37. The fixing device 36 has a heating roller 38 and a pressure roller 39.

  Furthermore, the color printer 1 of this embodiment is capable of double-sided printing and also has a paper conveyance path 41 for double-sided printing. A first transport roller 42 and a second transport roller 43 are arranged in the paper transport path 41. The color printer 1 also has a manual paper feed roller 44 for manual paper feed.

  Furthermore, the color printer 1 of this embodiment has various motors 51 to 58. The main motor 51 is for rotationally driving the photosensitive member 15, the paper feed roller 33, the intermediate transfer belt 11 and the like of the black image cartridge 10K. The developing motor 52 is used to rotationally drive a developing roller or the like built in the developing device 17 of the black image cartridge 10K. The color PC motor 53 is for rotationally driving the photoconductor 15 of the image cartridges 10Y, 10M, and 10C other than black. The color developing motor 54 is for rotationally driving a developing roller or the like built in the developing device 17 of the image cartridges 10Y, 10M, and 10C other than black.

  The toner replenishing motors 55 and 56 are for replenishing the toner of each color to the developing device 17 of each color and rotating the stirring blade 22 inside the toner bottle. The toner stored in the toner bottles 21Y, 21M, 21C, and 21K for each color is supplied to the developing unit 17 for each color by rotating a conveying member such as an auger or a screw. In this embodiment, a toner supply motor 55 for yellow and magenta and a toner supply motor 56 for cyan and black are provided. The fixing motor 57 is for rotating the fixing device 36. The double-sided conveyance motor 58 is for rotating the first conveyance roller 42 and the second conveyance roller 43. In this embodiment, each of the motors 51 to 58 is a DC brushless motor.

  An image forming operation by the color printer 1 of this embodiment will be briefly described. When a black monochrome image is formed, the black photoconductor 15 and the intermediate transfer belt 11 are rotated by the main motor 51, and the black developing roller is rotated by the developing motor 52. Further, the main motor 51 rotates each roller (paper feed roller 33, timing roller 34, paper discharge roller 37, etc.) of the paper conveyance system.

  An electrostatic latent image based on the image data is formed by the exposure unit 18 on the photoreceptor 15 uniformly charged by the charger 16. The electrostatic latent image is developed by the developing device 17 and a toner image is formed on the photoreceptor 15. The toner image is once transferred to the intermediate transfer belt 11 and then transferred to the paper at the secondary transfer location. The sheet is conveyed to the secondary transfer location on the sheet conveyance path 32 by the rotation of the sheet feeding roller 33 and the timing roller 34.

  The toner image transferred to the paper is fixed on the paper by the fixing device 36. The pressure roller 39 of the fixing device 36 is rotated by driving the fixing motor 57. Further, the paper that has passed through the fixing device 36 is discharged by a paper discharge roller 37. When color printing is instructed, in addition to the main motor 51 and the development motor 52, the color PC motor 53 and the color development motor 54 are driven. As a result, the photosensitive members 15 of three colors other than black and the developing rollers of the respective colors are rotated.

  When double-sided printing is instructed, the double-sided conveyance motor 58 is driven in addition to the above. The paper on which printing on one side is completed is pulled back to the paper transport path 41 for double-sided printing, and printing is performed on the other side in the same procedure. When it is determined that the toner is consumed to some extent by the developing unit 17 and needs to be replenished, the toner replenishing motors 55 and 56 are driven, and the toner bottles 21Y, 21M, 21C, and 21K transfer the toner to the developing unit 17 of each color. Is replenished. Further, the toner in the toner bottle is appropriately stirred by the rotation of the stirring blade 22.

  Next, FIG. 2 shows an outline of the control configuration of the color printer 1 of the present embodiment. The color printer 1 includes an output control unit 61 and a controller unit 62 in order to control each unit. The output control unit 61 includes a CPU 63 that performs overall control processing, an image processing unit 64 that performs image data processing, and a nonvolatile memory 65 attached to the main body. Further, the output control unit 61 controls various units 66 included in the color printer 1 and performs writing and reading of the nonvolatile memory 67 attached to the various units.

  The output control unit 61 also controls the various motors 51 to 58. That is, the control signals are sent to the motors 51 to 58 and the speed signals of the motors 51 to 58 are received. The CPU 63 performs feedback control by switching the control signal according to the difference between the target speed based on the control signal and the detected speed obtained from the speed signal received from the motor. This feedback control stabilizes the rotational speed of each motor at a predetermined speed. As the control signal, an analog signal or a PWM signal proportional to the line voltage applied to the motor is used. The speed signal received from the motor is a pulse signal having a frequency proportional to the speed of each motor.

  A non-volatile memory 65 attached to the main body stores adjustment values such as mechanical dimensions. The various units 66 include, for example, a toner bottle and an imaging unit. In the nonvolatile memory 67 attached to each unit, for example, the remaining amount of toner is stored in the memory attached to the toner bottle, and the number of printed sheets is stored in the memory attached to the imaging unit. The controller unit 62 is connected to an external personal computer 2 or the like and receives an instruction input.

Next, in the present embodiment, control when two motors are started simultaneously will be described. Here, the case where the main motor 51 and the developing motor 52 are started simultaneously will be described as an example. However, the control method is the same even when other motors are started or when three or more motors are started. In this embodiment, one of the following two control methods (A) time share control and (B) power suppression control is performed. Note that (C) set time standby control is a conventional technique for reference, and is a starting method for starting up two motors in turn.
(A) Time share control (see Fig. 3)
(B) Power suppression control (see FIG. 4)
(C) Set time standby control (see FIG. 5)

  First, (A) time share control will be described. Time share control is a start-up control method that alternately supplies power to each motor for a short time. As shown in the uppermost “main motor control signal” in FIG. 3, first, an acceleration control signal is sent to the main motor 51 for a period Ta. In the figure, the horizontal axis indicates the passage of time. The timing of sending the control signal is marked with a color in the figure.

  With this signal, as shown in the graph of “main motor rotation speed” in the figure, the main motor 51 starts rotating and is accelerated to some extent. At this time, the maximum value of the current allowed by the output control unit 61 to flow through the main motor 51 is compared with the current value of the subsequent period as shown in the graph of “main motor allowable current value” in the figure. It has been quite large. This is because, in the initial stage from the start of startup, a larger amount of current is required as compared with acceleration from a state of rotating to some extent. Therefore, the other motors are not started simultaneously during this period Ta.

  Next, during the period Tb in FIG. 3, as shown in the “main motor control signal” and “development motor control signal”, the transmission of the acceleration control signal to the main motor 51 is temporarily stopped, and instead, the development motor 52 is replaced. Sends an acceleration control signal. As a result, as shown in the graph of “development motor rotation speed” in the figure, the development motor 52 starts to rotate. At this time, the maximum value of the current allowed by the output control unit 51 to flow to the developing motor 52 is the same as in the case of the main motor as shown in the graph of “developing motor allowable current value” in the figure. Compared to the current value during the period, it is considerably large. Therefore, the other motors are not started simultaneously during this period Tb.

  As shown in FIG. 3, no acceleration control signal is sent to the main motor 51 during the period Tb. Accordingly, while the rotation speed of the main motor 51 is not sufficiently increased, the main motor 51 simply rotates by inertia during the period Tb. Further, the power supplied to each motor by the acceleration control signal sent as described above in the present control method is the same as that supplied when only one motor is started. Hereinafter, this acceleration control signal is referred to as a maximum acceleration signal. The acceleration control signal sent to each motor in the conventional control method (C) set time standby control is also this maximum acceleration signal.

  In the next period Tc, transmission of the acceleration control signal to the developing motor 52 is temporarily stopped, and a short-time acceleration control signal is transmitted to the main motor 51 again. Note that the maximum value of current allowed by the output control unit 51 to flow through the main motor 51 is slightly smaller in the period Tc than in the period Ta as shown in the graph of “main motor allowable current value”. . This is because the current value necessary to further increase the rotation speed of the motor gradually decreases as the rotation speed of the motor increases. The allowable maximum current value is gradually reduced thereafter until the constant speed rotation state is reached.

  As shown in “main motor control signal” and “development motor control signal” in FIG. 3, during the acceleration control period, a control signal to the main motor 51 and a control signal to the development motor 52 are alternately sent. The Accordingly, the rotation speeds of the main motor 51 and the developing motor 52 are gradually increased alternately. Then, the power supply time for each motor and the maximum number of times of supply are set in advance so that the two motors finally have a predetermined rotational speed almost simultaneously.

  As described above, this short-time power supply is repeated, and when both the main motor 51 and the developing motor 52 reach a predetermined rotational speed, the start-up control based on this time sharing is terminated. Since the rotation speed of the motor is fed back from each motor to the output control unit 61, the timing for ending this process can be determined based on the result. It should be noted that if the required rotation speed cannot be obtained even if the preset maximum number of times of supply is exceeded, an error is determined.

  Thereafter, as indicated by “constant speed control” in FIG. 3, both motors perform constant speed rotation control. In this way, there is almost no standby time when the main motor 51 is in the constant speed rotation state, and it is possible to start both motors in a short time while suppressing unnecessary rotation time. Here, a step-like pattern in which the rotation speed of each motor increases corresponds to an acceleration pattern. In order to obtain this acceleration pattern, the output control unit 61 functions as an activation control unit when sending a series of acceleration control signals to each motor.

  In this process, the transmission time for transmitting the acceleration control signal may be different depending on the type of motor. In addition, the transmission time for each transmission of the acceleration control signal to one motor may be always constant or may gradually change. Alternatively, the total time or total number of times of acceleration control may be stored in accordance with the combination of motors that are simultaneously started up, and this processing may be performed until the time or number of times is reached. The speed control of each motor may be performed by general PID control or the like. Note that the order of motors that start acceleration may be reversed.

  When three or more motors are started up at the same time, a maximum acceleration signal may be sequentially sent to each motor, and control may be performed to alternately accelerate each short time. Alternatively, two or more of the three or more motors that are started simultaneously may be accelerated so as not to accelerate the remaining one or more, and the accelerating motors may be sequentially switched. In this case, it is preferable to use (B) described later together. That is, it is preferable to send a signal with a smaller supply power in accordance with the number of motors that accelerate at the same time instead of the maximum acceleration signal.

  Next, (B) power suppression control will be described. The power suppression control is a process of suppressing the power supplied to each motor and starting up slowly at the same time. That is, the maximum power is distributed to two or more motors, and small power is supplied to both simultaneously. As shown in FIG. 4, when this control method is adopted in the present embodiment, an acceleration control signal corresponding to about half of the maximum value (hereinafter referred to as a half acceleration signal) is sent to the main motor 51 and the developing motor 52, respectively. Is sent out. This half acceleration signal is an instruction to supply about half of the power compared to the maximum acceleration signal.

  Examples of a method for halving the power include constant current control and constant voltage control. When performing constant current control, the current value may be controlled to be about half that of the maximum acceleration. In addition, when performing constant voltage control, frequency modulation control is used for each motor, and the ON / OFF duty is the same as that at the maximum acceleration and the frequency is different. Alternatively, the frequency may be the same as at the maximum acceleration and the duty may be different.

  For example, when the motors of the main motor 51 and the developing motor 52 are started with only one, the PWM duty value of the power to be supplied is controlled to be used as the supply power for starting in this embodiment. To do. As a result, about half of the electric power at the time of acceleration by the maximum acceleration signal is supplied. However, in order to prevent the inrush currents from overlapping, it is preferable that the timing at which the half acceleration signal is first sent to both motors is slightly shifted.

  As shown in FIG. 4, the maximum current value allowed for each motor is about half of that shown in FIG. Even in the case of this control method, the maximum allowable current value gradually decreases as the rotational speed of each motor gradually increases. In this processing method, when a predetermined startup time elapses, this control is terminated and both are shifted to constant speed control.

  For reference, the prior art (C) set time standby control will also be described. In this control method, as shown in FIG. 5, first, the main motor 51 is started at full acceleration and accelerated until it reaches a constant speed rotation state. In this state, the main motor 51 is put on standby, and then the developing motor 52 is started at full acceleration. A maximum acceleration signal is sent to any motor at startup to accelerate in a relatively short time. The maximum current value allowed for each motor is increased immediately after start-up, but is gradually decreased. When waiting until a sufficient time has elapsed for the start-up of the developing motor 52, both motors shift to constant speed control.

  In the graph of “main motor rotational speed” in FIG. 5, the rotational speed pattern according to the control method of (A) and (B) of this embodiment is indicated by a broken line. As can be seen from this figure, according to the present embodiment, the amount of useless rotation is reduced by an amount corresponding to the hatched area in the figure compared with the conventional pattern.

  Next, the motor starting process of this embodiment will be described with reference to the flowcharts of FIGS. This process is executed by the output control unit 61 when the motors 51 to 58 of the color printer 1 are started. For example, it is executed at the time of warm-up when the power is turned on, when returning from the sleep state, when switching from monochrome printing to color printing, and the like.

  In the main routine shown in FIG. 6, first, the number of motors that are simultaneously started is acquired (S101). At this time, the output control unit 61 functions as an activation number acquisition unit. Next, it is determined whether the number acquired in S101 is plural (S102). When only one motor is started (S102: No), a maximum acceleration signal is sent to the motor (S103), and the motor is started in a short time.

  When a plurality of motors are activated simultaneously (S102: Yes), a plurality of motor activation processes of the present invention are performed (S104). That is, either (A) time share control (FIG. 7) or (B) power suppression control (FIG. 8) is performed. Which of these may be performed may be determined in advance, or may be determined each time depending on the number of motors to be started and the type of motors. In any case, when the startup process is completed, the main routine is also completed. In the following, x is the number of motors that start simultaneously.

  In S103 of FIG. 6, when (A) time share control is performed, the time share control process shown in FIG. 7 is executed. When this process is executed, first, numbers 1 to x are assigned to the motors to be started at the same time for convenience (S201). This number corresponds to the starting order with a slight difference. Therefore, numbering may be performed in consideration of the start order. Then, starting is started in order from the motor with the smallest number x.

  Therefore, the number of the motor to be started at each time is represented by y, and y is first set to 1 (S202). Next, the time for sending the current acceleration control signal to the motor of number y (here 1) is set in the output timer (S203). Then, the set output timer is started and an acceleration control signal is sent to the motor of number y (S204). Until the output timer expires (S205: No), the acceleration control signal is continuously sent to the motor of number y (S204).

  When the output timer ends (S205: Yes), the acceleration control signal to the motor of number y is stopped. Then, y is incremented (S206). Then, it is determined whether y is less than or equal to x (S207). Here, since y = 2 and x is 2 or more, S207 is determined as Yes.

  Next, it is determined whether or not the acceleration processing for all the motors has been completed (S209). That is, it is determined whether all the activated motors have reached a predetermined speed and have shifted to constant speed control. Since all the motors do not reach the constant speed control by one acceleration control, it is determined as No (S209: No). Then, returning to S203, acceleration control of the second motor is performed.

  This is repeated, and when the first acceleration is completed for all the motors that are started simultaneously, y exceeds x in S207 (S207: No). Therefore, in order to perform the second acceleration in order from the first motor, y is returned to 1 (S208). Then, an acceleration signal is sent to each motor for a short time until the second acceleration of all the motors is completed and y> x again (S207: No).

  Then, it is determined whether or not the acceleration processing for all the motors has been completed (S209). If there is a motor that has not yet reached the constant speed control (S209: No), the process returns to S203 and the acceleration control is repeated. If it is determined that all the activated motors have reached a predetermined speed and have shifted to constant speed control (S209: Yes), this process is terminated. This completes the explanation of (A) time share control.

  In S103 of FIG. 6, when (B) power suppression control is performed, the power suppression control process shown in FIG. 8 is executed. When this process is executed, first, supply power to be supplied for starting each motor is calculated (S301). That is, for each motor, the power supplied when receiving the maximum acceleration signal is divided by the number of motors, and the result is used as the power supplied to the motor. Note that the power supplied to the motor is often different for each motor. When the power supply for each motor is calculated individually by using a weighting factor or preparing a reference table so that all motors reach their predetermined speeds by starting control for almost the same time, Good.

  Next, the supplied power calculated in S301 is output to all the motors to be started (S302). At this time, it is preferable to start the output in order by providing a time difference corresponding to the time corresponding to the inrush current. In this state, it waits until a predetermined output time elapses (S303). When the output time has elapsed, this process is terminated. This completes the explanation of (B) power suppression control.

  As described above in detail, according to the color printer 1 of the present embodiment, the simultaneously activated motors can be started up almost simultaneously by time share control or power suppression control. Although the time taken to start each motor is longer than the conventional one, the total motor starting time of the color printer 1 of this embodiment is almost the same. In addition, there is almost no time for the main motor to wait in the constant speed rotation state, and the time for unnecessary rotation can be suppressed. Therefore, it is an image forming apparatus that suppresses the unnecessary rotation time of the motor for standby in the constant speed rotation state, and prevents the rotation amount from being increased particularly in the main motor.

In addition, this form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
For example, the arrangement and sharing of each motor is an example, and more motors may be provided. It is also possible to apply to motors other than DC motors.

1 is a schematic configuration diagram of a color printer according to an embodiment. It is a block diagram which shows the outline of a control structure of the color printer of this form. It is explanatory drawing which shows the change of the rotational speed of the motor by time share control. It is explanatory drawing which shows the change of the rotational speed of the motor by electric power suppression control. It is explanatory drawing which shows the change of the rotational speed of the motor by setting time standby control. It is a flowchart which shows the main routine of the motor starting process of this form. It is a flowchart which shows the control processing by time share control. It is a flowchart which shows the control processing by electric power suppression control.

Explanation of symbols

1 Color Printer 10Y, 10M, 10C, 10K Image Cartridge 51-58 Motor 61 Output Control Unit

Claims (5)

An image having an image forming unit that has a plurality of rotating bodies and forms an image by the rotation, a plurality of motors that drive at least one of the plurality of rotating bodies, and a drive control unit that controls the plurality of motors In the forming apparatus, the drive control unit includes:
A startup number acquisition unit for acquiring the number of motors to be started according to the operation status of the image forming unit;
The activation number acquisition unit sets the activation acceleration pattern according to the number acquired, and if the number is large, sets a gentle acceleration pattern compared to the acceleration pattern set when the number is small. An acceleration pattern setting section;
A start control unit that controls start of the plurality of motors in parallel according to an acceleration pattern set by the acceleration pattern setting unit;
An image forming apparatus comprising: a constant speed control unit configured to perform constant speed control of the plurality of motors that have been activated. The image forming apparatus according to claim 1,
The acceleration pattern set by the acceleration pattern setting unit when there are a plurality of numbers acquired by the activation number acquisition unit is a step-like acceleration pattern that repeats an acceleration period and a non-acceleration period;
The activation control unit sets a part of the motors to be activated in an accelerated state and a remaining one in a non-accelerated state according to the stepped acceleration pattern, and sequentially replaces the motors in the accelerated state. An image forming apparatus. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the activation control unit reduces the power supplied to the activated motor when the number of activated motors is large as compared with a case where the number is small. The image forming apparatus according to claim 3,
The image forming apparatus according to claim 1, wherein when there are a plurality of motors to be activated, the activation control unit starts activation of each motor at a timing shifted from each other. The image forming apparatus according to claim 3 or 4, wherein:
When there are a plurality of motors to be activated, the activation control unit sets the power supplied to each motor to be activated to a value obtained by dividing the power supplied when the number of motors to be activated is 1 by the number. A featured image forming apparatus.

Images