JP2008039842A - Power supply voltage control apparatus, method for controlling power supply voltage, program for making computer execute the method, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply voltage control apparatus capable of reducing the variations in power supply voltage which is caused at the start of use of a load, such as heater, stabilizing the operation of the apparatus and performing efficient power supply. <P>SOLUTION: In the power supply voltage control apparatus 100 applied to an image forming apparatus, an input voltage/current detecting part 12 detects the input voltage from an AC power supply (commercial power supply) inputted to the image forming apparatus, an input power calculating part 13 detects the voltage drop value at the start of driving the load, a drive control part 3 compares the voltage drop value with a prescribed threshold; and when the voltage drop value is larger than the prescribed threshold, the current that flows into a main heater 5 is controlled by soft start, to reduce sudden voltage drop. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply voltage control device, a power supply voltage control method, a program for causing a computer to execute the method, and an image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus, a large current is consumed in a load such as a fixing device, thereby causing a voltage fluctuation in an AC power source to which the load is connected. In other words, the image forming apparatus is adversely affected by the voltage drop.

  In order to cope with this, the technology disclosed in Japanese Patent Application Laid-Open No. 2001-22220 is configured so that the ON timing of the heaters is not duplicated in an apparatus composed of a plurality of heaters, so that the inrush current from the AC power source to the heaters. We have devised a technology to reduce the voltage fluctuation caused by

Japanese Patent Laid-Open No. 2001-22220

  However, according to the technique of this document, there is a problem that it is a technique based on the premise that a plurality of heaters are provided, and cannot be applied when only a single heater is provided. In addition, the magnitude of the inrush current varies depending on the temperature state of the heater. However, since there is no means for controlling the difference in current magnitude, it is impossible to efficiently supply power to the heater. There was a problem.

  The present invention has been made in view of the above, and a power supply voltage control device that can efficiently supply power to a load such as a heater by reducing fluctuations in the power supply voltage caused by the use state of the load such as a heater. An object of the present invention is to provide a power supply voltage control method, a program for causing a computer to execute the method, and an image forming apparatus.

  In order to solve the above-mentioned problems and achieve the object, the invention according to claim 1 is a power supply voltage control device, wherein the voltage detection means for detecting an input voltage from an AC power supply, and the voltage detection when driving a load. The voltage drop amount detection means for detecting the voltage drop amount from the voltage detected by the means, the comparison means for comparing the voltage drop amount detected by the voltage drop amount detection means with a predetermined threshold, and the comparison means And a voltage control means for performing a voltage control process for reducing the voltage drop amount by controlling a current supplied to the load when the voltage drop amount is larger than a predetermined threshold value.

  According to a second aspect of the present invention, in the power supply voltage control apparatus according to the first aspect, when the load is a heater, the voltage control means changes the phase width and the maximum value of the current to the heater. A soft start process for suppressing an inrush current and reducing the voltage drop amount is performed on the load.

  According to a third aspect of the present invention, in the power supply voltage control apparatus according to the first or second aspect, when the load is an AC motor, an inrush current is obtained by changing a phase width and a maximum value of a current to the AC motor. It is characterized in that a process for suppressing the above is performed.

  According to a fourth aspect of the present invention, in the power supply voltage control apparatus according to any one of the first to third aspects, the voltage detection unit includes a photocoupler whose output changes linearly according to a change in an input AC voltage, and The detection is performed by detecting a DC voltage by a photoelectric element that generates a current by irradiation from the photocoupler.

  According to a fifth aspect of the present invention, in the power supply voltage control apparatus according to any one of the first to fourth aspects, a rectifying unit that converts an AC current input from the AC power source into a DC current, and a conversion by the rectifying unit. A power storage means for storing the DC current, a charge / discharge means for charging and discharging the power storage means, and an input power calculation means for calculating the power of the input AC current. The control means performs the voltage control process by charging the power storage means when the input power calculated by the input power calculation means exceeds a predetermined threshold value.

  According to a sixth aspect of the present invention, in the power supply voltage control apparatus according to the fifth aspect, the voltage control means is configured to store the power storage when the input power calculated by the input power calculation means does not exceed a predetermined threshold value. The voltage control process is performed by discharging the means.

  According to a seventh aspect of the present invention, in the power supply voltage control apparatus according to the fifth or sixth aspect, the voltage control means chops the primary side of the rectifying means to convert it into a DC current, and by the rectifying chopping, The power storage means stores power.

  According to an eighth aspect of the present invention, in the power supply voltage control device according to any one of the fifth to seventh aspects, the power storage means is an electric double layer capacitor.

  The invention according to claim 9 is a power supply voltage control method in a power supply voltage control device, wherein a voltage detection step of detecting an input voltage from an AC power source by a voltage detection means, and a load driving by a voltage drop detection means. Sometimes, a voltage drop amount detecting step for detecting a voltage drop amount from the voltage detected in the voltage detecting step, and a comparison for comparing the voltage drop amount detected in the voltage drop amount detecting step with a predetermined threshold by the comparison means. And a voltage control for performing a voltage control process for reducing a voltage drop amount by controlling a current flowing to the load when the voltage drop amount compared in the comparison step is greater than a predetermined threshold by the voltage control means. And a process.

  According to a tenth aspect of the present invention, in the power supply voltage control method according to the ninth aspect, when the load is a heater, the voltage control step changes the phase width and the maximum value of the current to the heater. A soft start process for suppressing an inrush current and reducing the voltage drop amount is performed on the load.

  According to an eleventh aspect of the present invention, in the power supply voltage control method according to the ninth or tenth aspect, in the voltage control step, when the load is an AC motor, the phase width and the maximum value of the current to the AC motor are determined. It is characterized in that processing is performed to suppress the inrush current by changing.

  According to a twelfth aspect of the present invention, in the power supply voltage control method according to any one of the ninth to eleventh aspects, the voltage detection step includes a photocoupler whose output changes linearly according to a change in an input AC voltage, and The detection is performed by detecting a DC voltage by a photoelectric element that generates a current by irradiation from the photocoupler.

  According to a thirteenth aspect of the present invention, in the power supply voltage control method according to any one of the ninth to twelfth aspects, a rectifying step of converting an AC current input from the AC power source into a DC current by a rectifying unit, A storage step of storing the DC current converted in the rectification step by means, a charge / discharge step of charging and discharging the storage unit by the charge / discharge unit, and an AC current input by the input power calculation unit. An input power calculation step for calculating the power of the input power, wherein the voltage control step is performed by charging in the power storage step when the input power calculated in the input power calculation step exceeds a predetermined threshold value. The voltage control process is performed.

  According to a fourteenth aspect of the present invention, in the power supply voltage control method according to the thirteenth aspect, in the voltage control step, when the input power calculated in the input power calculation step does not exceed a predetermined threshold, the power storage The voltage control process is performed by discharging the means.

  According to a fifteenth aspect of the present invention, in the power supply voltage control method according to the thirteenth or fourteenth aspect, the voltage control step includes an inrush current by changing a phase width and a maximum value of a primary side current of the rectifying means. And is converted into a DC current, and the rectified current is stored in the power storage step.

  According to a sixteenth aspect of the present invention, in the power supply voltage control method according to any one of the thirteenth to fifteenth aspects, the power storage step stores power in an electric double layer capacitor.

  According to a seventeenth aspect of the present invention, a program causes a computer to execute the power supply voltage control method according to any one of the ninth to sixteenth aspects.

  According to an eighteenth aspect of the present invention, there is provided a driving unit that drives a transfer member, and a visible image that forms an electrostatic latent image on a photosensitive member according to image data, forms a visible image from the electrostatic latent image, and transfers the image to the transferring member. Forming means, drive control means for controlling the drive means, image output means for transferring a visible image on the transfer member driven by the drive means to a recording medium, the drive means, visible image forming means, An image forming apparatus comprising: a drive control unit; and a power source unit that supplies power to the image output unit, wherein the power source unit detects a voltage input from an AC power source, and drives the load. A voltage drop detection means for detecting a voltage drop amount from the voltage detected by the voltage detection means; a comparison means for comparing the voltage drop amount detected by the voltage drop detection means with a predetermined threshold; and the comparison To the means Voltage control means for performing a voltage control process for controlling the current flowing to the load to reduce the voltage drop amount when the compared voltage drop amount is larger than a predetermined threshold value. .

  According to a nineteenth aspect of the present invention, in the image forming apparatus according to the eighteenth aspect, when the load is a heater, the voltage control unit rushes by changing a phase width and a maximum value of a current to the heater. A soft start process for suppressing current and reducing the voltage drop amount is performed on the load.

  According to a twentieth aspect of the present invention, in the image forming apparatus according to the twentieth or nineteenth aspect, the voltage control unit changes a phase width and a maximum value of a current to the heater when the load is an AC motor. Accordingly, the load is subjected to a soft start process for suppressing an inrush current and reducing the voltage drop amount.

  According to the first aspect of the present invention, the voltage detection means detects the input voltage from the AC power source, and the voltage drop amount detection means detects the voltage drop amount from the voltage detected in the voltage detection step when driving the load. The voltage drop amount is detected and compared with a predetermined threshold by the comparison means, and when the voltage drop amount is larger than the predetermined threshold by the voltage control means, the current flowing to the load is controlled to reduce the voltage drop amount. A voltage control process is performed. With this configuration, it is possible to efficiently supply power to the load while suppressing fluctuations in the power supply voltage.

  According to the second aspect of the present invention, when the load is a heater, the soft start process for suppressing the inrush current and reducing the voltage drop amount is performed by changing the phase width and the maximum value of the current to the heater. Thus, it is possible to efficiently supply power to the heater while suppressing power supply voltage fluctuations that are likely to fluctuate depending on the temperature state.

  According to the third aspect of the present invention, when the load is an AC motor, the inrush current is suppressed by changing the phase width and the maximum value of the current to the AC motor. It is possible to efficiently supply power to the AC motor while suppressing easy power supply voltage fluctuation.

  According to the invention of claim 4, a simple configuration can be obtained by detecting a DC voltage by a photocoupler whose output changes linearly due to a change in the input AC voltage, and a photoelectric element that generates a current by irradiation from the photocoupler. Thus, it is possible to accurately detect a voltage drop, and it is possible to efficiently supply power to a load while suppressing fluctuations in power supply voltage.

  According to the fifth aspect of the present invention, the input AC current is converted into the DC current, the converted DC current is stored in the power storage means, and the power storage means is charged and discharged by the charge / discharge means to be input. When the power of the AC current is calculated and the input power exceeds a predetermined threshold, the power is efficiently supplied to the load while suppressing power supply voltage fluctuations by charging the power storage means and performing voltage control processing. There is an effect that becomes possible.

  According to the sixth aspect of the present invention, when the input power does not exceed the predetermined threshold value, the power storage means is discharged and subjected to voltage control processing, whereby the power supply voltage fluctuation is suppressed and the load is efficiently supplied. There is an effect that it becomes possible to supply power.

  According to the invention of claim 7, by changing the phase width and maximum value of the current on the primary side of the rectifying means, the inrush current is suppressed and converted into a DC current, and the rectified current causes the power storage means to By accumulating power, it is possible to efficiently supply power to the load while suppressing fluctuations in the power supply voltage.

  According to the eighth aspect of the present invention, it is possible to efficiently supply power to the load while suppressing power supply voltage fluctuation by storing the electric double layer capacitor.

  According to the ninth aspect of the present invention, the voltage detection means detects the input voltage from the AC power source, and the voltage drop amount detection means detects the voltage drop amount from the voltage detected in the voltage detection step when driving the load. The voltage drop amount is detected and compared with a predetermined threshold by the comparison means, and when the voltage drop amount is larger than the predetermined threshold by the voltage control means, the current flowing to the load is controlled to reduce the voltage drop amount. A voltage control process is performed. With this configuration, it is possible to efficiently supply power to the load while suppressing fluctuations in the power supply voltage.

  According to the tenth aspect of the present invention, when the load is a heater, the soft start process for suppressing the inrush current and reducing the voltage drop amount is performed by changing the phase width and the maximum value of the current to the heater. Thus, it is possible to efficiently supply power to the heater while suppressing power supply voltage fluctuations that are likely to fluctuate depending on the temperature state.

  According to the eleventh aspect of the present invention, when the load is an AC motor, the inrush current is suppressed by changing the phase width and the maximum value of the current to the AC motor. It is possible to efficiently supply power to the AC motor while suppressing easy power supply voltage fluctuation.

  According to the twelfth aspect of the present invention, a simple configuration can be obtained by detecting a DC voltage generated by a photocoupler whose output changes linearly due to a change in an input AC voltage, and a photoelectric element that generates a current by irradiation from the photocoupler. Thus, it is possible to accurately detect a voltage drop, and it is possible to efficiently supply power to a load while suppressing fluctuations in power supply voltage.

  According to the thirteenth aspect of the present invention, the input AC current is converted into the DC current, the converted DC current is stored in the power storage means, and the power storage means is charged and discharged by the charge / discharge means to be input. When the power of the AC current is calculated and the input power exceeds a predetermined threshold, the power is efficiently supplied to the load while suppressing power supply voltage fluctuations by charging the power storage means and performing voltage control processing. There is an effect that becomes possible.

  According to the fourteenth aspect of the present invention, when the input power does not exceed the predetermined threshold value, the power storage means is discharged and subjected to voltage control processing, thereby suppressing the power supply voltage fluctuation and efficiently supplying the load. There is an effect that it becomes possible to supply power.

  According to the fifteenth aspect of the present invention, the inrush current is suppressed and converted into the DC current by changing the phase width and the maximum value of the primary side current of the rectifying means, and the rectified current is supplied to the power storage means by the rectified current. By accumulating power, it is possible to efficiently supply power to the load while suppressing fluctuations in the power supply voltage.

  According to the sixteenth aspect of the present invention, it is possible to efficiently supply power to the load while suppressing power supply voltage fluctuation by storing the electric double layer capacitor.

  According to the invention of claim 17, there is an effect that it is possible to cause a computer to execute the power supply voltage control method according to any one of claims 9 to 16.

  According to the invention of claim 18, the input voltage from the AC power source is detected by the voltage detection means, and the voltage drop amount is detected from the voltage detected in the voltage detection step by the voltage drop amount detection means when the load is driven. The voltage drop amount is detected and compared with a predetermined threshold by the comparison means, and when the voltage drop amount is larger than the predetermined threshold by the voltage control means, the current flowing to the load is controlled to reduce the voltage drop amount. A voltage control process is performed. With this configuration, it is possible to efficiently supply power to the load while suppressing fluctuations in the power supply voltage, and it is possible to provide an image forming apparatus that can form a high-quality image.

  According to the nineteenth aspect of the present invention, when the load is a heater, the soft start process for suppressing the inrush current and reducing the voltage drop amount is performed by changing the phase width and the maximum value of the current to the heater. Thus, it is possible to provide an image forming apparatus that can efficiently supply power to the heater while suppressing power supply voltage fluctuations that are likely to fluctuate depending on the temperature state, and can form high-quality images.

  According to the twentieth aspect of the present invention, when the load is an AC motor, the inrush current is suppressed by changing the phase width and the maximum value of the current to the AC motor. It is possible to provide an image forming apparatus capable of efficiently supplying power to the AC motor while suppressing easy power supply voltage fluctuations and capable of forming a high-quality image.

  Exemplary embodiments of a power supply voltage control device, a power supply voltage control method, a program for causing a computer to execute the method, and an image forming apparatus according to embodiments of the present invention are described below with reference to the accompanying drawings. It explains in detail along with.

(1. Embodiment 1)
The power supply voltage control apparatus according to the first embodiment is applied to, for example, an image forming apparatus, detects an input voltage from an AC power input to the image forming apparatus, and sets a voltage drop amount as a predetermined threshold when driving a load. In comparison, when the voltage drop amount is larger than a predetermined threshold value, the voltage drop amount is reduced by applying a soft start process that suppresses the inrush current and reduces the voltage drop amount by changing the phase width and maximum value of the current. With this configuration, it is possible to efficiently supply power to the load while suppressing fluctuations in the power supply voltage.

  FIG. 1 is a functional block diagram of the power supply voltage control apparatus according to the first embodiment. Since the image forming apparatus itself is a known technique, the description will be given later. Here, power supply voltage control in an image forming apparatus incorporating the power supply voltage control apparatus will be described as an example.

  The power supply voltage control apparatus 100 according to the first embodiment includes an input unit 2, a drive control unit 3, a fixing unit 4, a main heater control unit 7, a rectification charging unit 8, a charge / discharge switching unit 9, an electric double layer capacitor 10, a voltage A detection unit 11, an input voltage / current detection unit 12, an input power calculation unit 13, and a power supply unit 14 are provided.

  The fixing unit 4 includes a main heater 5 and a sub-heater 6 and fixes an image formed on the recording paper. The drive control unit 3 performs drive control of a process for forming an image. In particular, the drive control unit 3 controls the temperature of the fixing unit 4. The rectification charging unit 8 supplies power to the sub heater 6.

  The charging / discharging switching unit 9 is disposed between the rectification charging unit 8 and the sub heater 6 and switches charging / discharging of the electric double layer capacitor 10 to control the voltage of the sub heater 6. The voltage detector 11 detects the voltage of the electric double layer capacitor 10.

  The input voltage / current detector 12 detects a voltage / current input from the commercial power supply 1 via the input unit 2. The input power calculation unit 13 is disposed between the input voltage / current detection unit 12 and the drive control unit 3 and calculates changes in the input voltage and power.

  The power supply unit 14 transforms the commercial input received from the commercial power supply 1 to 5 V, for example, as a control output for driving and controlling a process for forming an image, and to 24 V as a drive output, for example. To the drive control unit 3.

  The drive control unit 3 performs processing such as initial setting for starting the image forming operation, and controls on to control the main heater so as to raise the temperature of the fixing unit 4 to a fixable temperature, for example, 180 ° C. The signal is output to the main heater control unit 7. The main heater control unit 7 receives a control signal from the drive control unit 3 and controls the main heater 5.

  The main heater control unit 7 is configured by a triac and supplies power to the main heater 5. The temperature sensor (thermistor) 4t detects the temperature of the fixing unit 4 and is controlled by the drive control unit 3 so as to reach a target of 180 ° C. When the temperature of the fixing unit 4 reaches 180 ° C., the image forming operation is possible, that is, the standby state. From this state, the image forming operation starts as necessary.

  When the image forming operation starts, a series of operations such as document reading, charging of the photosensitive member, writing on the photosensitive member, development, and transfer for image formation start. At the same time, the recording paper is conveyed, an image is transferred and formed on the recording paper, and the recording paper passes through the fixing unit 4 so that the image is fixed on the recording paper.

  Generally, the input current during the image forming operation varies greatly. In the case of a 100V commercial power supply, the maximum value (= rated) of this input current is generally 15 A, and it is necessary to keep it below this value. The maximum value is limited to 15A, but the minimum value during the image forming operation may be 10A or less. These fluctuation factors are because the on / off power and timing of various driving powers for the main heater 5 of the fixing unit 4 and the various driving powers of the scanner, the photosensitive member, and the like are different.

  In the first embodiment, a threshold value is set in advance for the input voltage, and the input voltage detected by the input voltage current detection unit 12 is input to the input power calculation unit 13 and the drive control unit 3 as input voltage data.

  The input voltage / current detector 12 includes a zero-cross detection circuit and a voltage peak detection circuit (not shown), detects a half-wave voltage from the zero-cross, and calculates a voltage fluctuation value from the detected voltage.

  The drive control unit 3 compares the voltage fluctuation value with a preset threshold value, and performs energization control using the soft start of the heater if the voltage fluctuation value is equal to or less than the threshold value. Here, the voltage fluctuation is reduced by applying a load, and generally, a positive value is obtained by subtracting the voltage after power-on from the voltage before power-on. That is, the voltage drops after power is applied to the load.

  FIG. 2 is a table showing a soft start pattern corresponding to the voltage fluctuation value. FIG. 3 is a time chart showing a soft start pattern corresponding to the table used by the drive control unit 3. In FIG. 2, the threshold magnitude relationship is 0 <Tc1 <Tc2.

  Here, when the voltage fluctuation value Tc ≦ Tc1, the drive control unit 3 controls the pattern 1. In addition, when the voltage fluctuation value Tc1 ≦ Tc <Tc2, the drive control unit 3 controls the pattern 2. When the voltage fluctuation value TC2 ≦ Tc, the drive control unit 3 controls the pattern 3. This is because when the voltage fluctuation value is larger, soft start with less voltage drop is executed.

  As another example of soft start, for example, when the threshold value is a1 <a2 <a3 with respect to the voltage fluctuation value x, when a1 ≦ x <a2, the phase control time is t1, and a1 ≦ If x <a2, the phase control time may be t2, and if a3 ≦ x, the phase control time may be t3. That is, it is desirable to increase the phase control time as the input voltage difference increases. This is to make the soft start effect.

  Thus, as a soft start for the main heater 5 of the fixing unit 4, for example, by outputting an ON signal and an OFF signal from the drive control unit 3, the output is gradually increased to 100% output by using phase control. By doing so, a rapid decrease in voltage fluctuation can be suppressed, and the rise of the main heater 5 can be made smooth. In this case, phase control can be performed using the setting table according to the input voltage difference.

  In this way, the fluctuation of the input current can be reduced by the energization control of the drive control unit 3. That is, it is improved so as to reduce the voltage fluctuation of the commercial power supply, and the quality of actual use of the commercial power supply is improved. As the input current changes suddenly, the voltage fluctuates, and the occurrence of problems such as flickering of lighting and malfunction of peripheral electronic devices can be suppressed.

  FIG. 4 is a flowchart for explaining the procedure of the input power supply voltage control according to the first embodiment. The input voltage / current detection unit 12 is in a state of detecting a trigger for AC input voltage detection start, such as when the power is turned on or when the heater is turned on (step S101), and when detected (Yes in step S101), the input voltage / current detection is performed. The unit 12 starts AC input voltage detection. The input voltage / current detector 12 detects the AC input voltage due to the heater being turned on by the input voltage corresponding to the half wave from the zero cross of the AC input (step S102).

  The input power calculation unit 13 calculates the pre-heater voltage Ta and the input voltage difference Tc between the heater ON Tb, and the input power calculation unit 13 determines whether Tc is equal to or greater than a certain threshold voltage difference. (Step S103). When the input power calculation unit 13 determines that the dormitory voltage difference is equal to or greater than the threshold value (Yes in step S103), the drive control unit 3 uses the soft start setting value table determined in advance by the input voltage difference. Based on the above, energization control to the heater is performed. The set value table is a correspondence table between threshold determination and soft start patterns as shown in FIG. 2 (step S104).

  If it is determined that the input voltage difference Tc is equal to or less than the threshold voltage difference (No in step S103), the drive control unit 3 performs normal energization control without performing soft start (step S105).

  FIG. 5 is a flowchart for explaining a procedure by which the drive control unit 3 selects a soft start pattern by threshold value position determination. When the input power calculation unit 13 determines that Tc ≦ Tc1 (Yes in step S201), the drive control unit 3 controls the main heater 5 by applying the soft start pattern of the pattern 1 (step S202). .

  If the input calculation control unit 13 further determines that Tc1 ≦ Tc <Tc2 (Yes in step S203), the drive control unit 3 applies the soft start pattern of pattern 2 to control the main heater 5. This is performed (step S204).

  If the input calculation control unit 13 further determines that Tc2 ≦ Tc (Yes in step S205), the drive control unit 3 applies the soft start pattern of the pattern 3 to control the main heater 5 ( Step S206).

  In this way, by controlling the inrush current and reducing the voltage drop by changing the phase width and maximum value of the current, it is possible to suppress fluctuations in the AC power supply voltage and suppress flicker. Can do. Further, by varying the control for each power supply voltage variation due to the temperature state of the device, it is possible to efficiently supply power to the heater while suppressing flicker.

(Application to image forming device)
The power supply voltage control apparatus according to the first embodiment can be applied to an image forming apparatus. In the image forming apparatus, particularly, when the power supply voltage is lowered due to the heater being turned on, flickering of the irradiated light may occur and the quality of the formed image may be lowered. This power supply voltage control device can prevent a deterioration in image quality due to a drop in power supply voltage. Hereinafter, although the image forming apparatus itself is a known technique, an image forming operation will be described.

  FIG. 6 is a diagram illustrating an image forming operation of the image forming apparatus. In the drawing, the appearance of a digital copying machine as an embodiment of the image forming apparatus is shown. The digital copying machine 100 includes a main body 110, a mass recording paper supply apparatus (hereinafter referred to as LCT) 111, and a finisher 112 that performs sorting, punching, stapling, and the like, and an automatic original supply apparatus for placing and reading an original on the main body 110. (Hereinafter referred to as ADF) 113 and an operation unit 114 for performing a reading mode, setting of a copy magnification, setting of a paper feed stage, setting of post-processing by the finisher 112, display to an operator, and the like.

  A paper feeding unit 115 is provided below the main body 110, and a finisher 112 is provided with a paper discharging unit 117. The inside of the digital copying machine 100 incorporates well-known mechanisms and control devices of the digital copying machine such as an exposure optical system, a paper feeding / conveying system, a developing system, a fixing system, and a paper discharging system, thereby realizing operation as a copying machine. is doing.

  That is, by placing a document on the ADF 113 and pressing a copy start key on the operation unit 114, the document is supplied onto a contact glass (not shown) under the ADF 113, and the document is illuminated with an illumination system and an imaging (not shown). Read by optical system. After various corrections and processing are performed on the read image data, a beam is irradiated by a laser diode in a writing system based on the image data, and an electrostatic latent image is formed on a photosensitive member (not shown).

  Thereafter, through a so-called electrophotographic process, a copy image is formed on the recording paper fed from the paper feeding unit 115 or 116 as instructed by the operation unit 114, and post-processing such as sorting, punching, stapling, etc. is performed by the finisher 112. Then, the paper is discharged to the paper discharge unit 117.

(2. Embodiment 2)
FIG. 7 is a functional block diagram of the power supply voltage control apparatus according to the second embodiment. The difference between the second embodiment and the first embodiment is that the load for changing the input voltage is an AC motor, and the control processing is performed by changing the chopping frequency with respect to the input voltage drop caused by the AC motor drive. It is a point to apply. That is, by changing the phase width and maximum value of the current, a process for suppressing the inrush current and reducing the voltage drop amount is performed. Hereinafter, differences from the first embodiment will be mainly described.

  The power supply voltage control apparatus 200 according to the second embodiment includes an AC motor 22 and a driver 21. The driver 21 drives the AC motor 22. The input voltage / current detector 12 detects an input voltage, detects an input voltage generated when driving of the AC motor is started, and detects fluctuations in the power supply voltage. The input power calculation unit 13 detects the power supply voltage, calculates a fluctuation value of the power supply voltage, and compares it with a threshold value.

  When the input power calculation unit 13 determines that the fluctuation value of the power supply voltage has exceeded the threshold value, the drive control unit 23 controls and drives the driver 21 by changing the PWM (Pulse Width Modulation) signal. The AC motor is driven and controlled by designating and outputting an active period in a designated cycle for outputting an analog quantity by the PWM signal. That is, soft staring is performed by adjusting the pulse width for actual energization.

  FIG. 8 is a diagram illustrating an example of a time chart of PWM control performed by the drive control unit with respect to the AC motor. When the voltage drop is detected immediately after the power is turned on as shown in FIG. 8, the driver 21 accepts the current only for a predetermined pulse width with respect to the current from the commercial power source 1 which is an AC power source, No current is accepted for pulse widths other than. Thereafter, control is performed to gradually widen the pulse width for receiving current. In the figure, such control is performed during the time period until t0 · 8, that is, for eight half waves, and thereafter, the current is received in one cycle for t1 in the figure. By controlling in this way, soft start control for the AC motor 22 is performed.

  Further, as a control for the voltage drop by the AC motor, the soft start process as shown in FIG. 3 may be executed using the table shown in FIG. 2 in the first embodiment.

  In this way, in the image forming apparatus, it is possible to reduce the power supply voltage drop that occurs when starting to drive the AC motor.

(3. Embodiment 3)
The power supply voltage control apparatus according to the third embodiment is different from the first embodiment in that it has a photocoupler (PC1) that linearly changes its output to a DC-converted voltage, and the primary side voltage fluctuation is caused by the photocoupler. This is the point of detecting voltage fluctuation by detecting photoelectric conversion.

  FIG. 9 is a circuit diagram illustrating a main part of an image forming apparatus having a power supply voltage control apparatus according to the third embodiment. A power supply voltage control apparatus 300 according to the third embodiment includes a fixing unit 4 and a power supply unit 30.

  The power supply unit 30 includes a bridge circuit (DB1) 31, a photocoupler 32, a capacitor 34, and a secondary side drive control unit 33. The current from the commercial power source 1 that is an AC power source passes through the bridge circuit 31 and the photo-coupler (PC1) 32 whose output changes linearly to a voltage. And input to the drive control unit 33.

  The drive control unit 33 detects voltage fluctuation by the A / D conversion function. With this configuration, by incorporating a photocoupler having a linear characteristic, it is possible to detect a power supply voltage fluctuation instantaneously and to control the current flowing through the load.

(4. Embodiment 4)
The difference between the fourth embodiment and the first embodiment is that the input power calculation unit 413 calculates the input power based on the input voltage and the input current detected by the input voltage / current detection unit 12. The threshold value is determined for the input power data. When the input power is high, the electric double capacitor is charged. When the input power is low, the electric double capacitor is discharged.

  FIG. 10 is a functional block diagram of an image forming apparatus including a power supply voltage control apparatus according to the fourth embodiment. The input power calculation unit 413 calculates input power based on the input voltage and input current detected by the input voltage / current detection unit 12, and outputs the calculated input power data to the drive control unit 403.

  The drive control unit 403 compares the received input power data with a preset threshold value, and transmits a control signal instructing charging or discharging to the rectification charging unit 8 based on the threshold determination. .

For example, when the threshold p1 <p2 and the input power calculated by the input power calculation unit 413 is p,
In the case of p <p1, the drive control unit 403 transmits a control signal instructing the rectification charging unit 8 to discharge.
In the case of p1 ≦ p <p2, a control signal instructing discharge and charge is not transmitted.
In the case of p2 <p, the drive control unit 403 transmits a control signal instructing charging to the rectification charging unit 8.

  As described above, the charge / discharge switching unit 9 switches between charging and discharging with respect to the electric double layer capacitor 10, whereby the electric double layer capacitor 10 performs charging or discharging operation.

  With this configuration, when the input power is too low, the electricity stored in the capacitor is compensated by flowing it to a load such as a heater. On the other hand, if the input power is too high, charging the capacitor can prevent overpowering the load.

  By controlling charging / discharging in this way, for example, the maximum power used by the apparatus is set to 1500 W, and the power control operation can be performed so as not to exceed this.

  Here, it is desirable to use an electric double capacitor. This is because the storage effect is much greater than that of a normal capacitor, and the configuration can be simplified compared to a storage battery.

  Here, in charging or discharging, as already described, a soft start method such as a PWM control method can be applied. That is, it is desirable to perform a soft start process that suppresses the inrush current and reduces the amount of voltage drop by changing the phase width and maximum value of the current. This is because sudden voltage fluctuations can be avoided even during power storage and discharge.

(5. Hardware configuration of image forming apparatus)
FIG. 11 is a block diagram showing a hardware configuration of an image forming apparatus incorporating the power supply voltage control apparatus according to the first embodiment.

  This image forming apparatus is configured as a multifunction peripheral (MFP) having multiple functions such as a fax machine and a scanner. As shown in the figure, this MFP has a configuration in which a controller 1210 and an engine unit 1260 are connected by a PCI (Peripheral Component Interconnect) bus. The controller 1210 is a controller that controls inputs from the FCUI / F 1230 and the keyboard 1220 operation display unit 1221 such as overall MFP control, document reading control, image processing control, rotation drive control, image output control, and various controls. . The engine unit 1260 is an image processing engine that can be connected to a PCI bus, and includes, for example, an image processing unit such as error diffusion and gamma conversion for acquired image data.

  The controller 1210 includes a CPU 1211, a north bridge (NB) 1213, a system memory (MEM-P) 1212, a south bridge (SB) 1214, a local memory (MEM-C) 1217, and an ASIC (Application Specific Integrated Circuit). 1216 and a hard disk drive (HDD) 1218, and the north bridge 1213 and the ASIC 1216 are connected by an AGP (Accelerated Graphics Port) bus 1215. The MEM-P 1212 further includes a ROM (Read Only Memory) 1212 a and a RAM (Random Access Memory) 1212 b.

  The CPU 1211 performs overall control of the MFP, has a chip set including the NB 1213, the MEM-P 1212, and the SB 1214, and is connected to other devices via the chip set.

  The NB 1213 is a bridge for connecting the CPU 1211 to the MEM-P 1212, the SB 1214, and the AGP bus 1215, and includes a memory controller that controls read / write to the MEM-P 1212, a PCI master, and an AGP target.

  The MEM-P 1212 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, and the like, and includes a ROM 1212a and a RAM 1212b. The ROM 1212a is a read-only memory used as a memory for storing programs and data, and the RAM 1212b is a writable and readable memory used as a memory for developing programs and data, an image drawing memory during image processing, and the like.

  The SB 1214 is a bridge for connecting the NB 1213 to a PCI device and peripheral devices. The SB 1214 is connected to the NB 1213 via a PCI bus, and an FCUI / F 1230 is also connected to the PCI bus.

  The ASIC 1216 is an IC (Integrated Circuit) for multimedia information processing having hardware elements for multimedia information processing, and has a role of a bridge for connecting the AGP bus 1215, the PCI bus, the HDD 1218, and the MEM-C 1217, respectively. .

  The ASIC 1216 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 1216, a memory controller that controls the MEM-C 1217, and a plurality of DMACs (Direct Memory) that perform image data rotation and the like using hardware logic. A universal serial bus (USB) 1240 and an IEEE (the Institute of Electrical Engineers) 1394 interface 1250 are connected via a PCI bus between the access controller and the engine unit 1260.

  The MEM-C 1217 is a local memory used as a transmission image buffer and a code buffer, and the HDD 1218 is a storage for storing image data, programs, font data, and forms.

  The AGP bus 1215 is a bus interface for a graphics accelerator card proposed for speeding up graphics processing. The AGP bus 1215 speeds up the graphics accelerator card by directly accessing the MEM-P 1212 with high throughput.

  The keyboard 1220 and the operation display unit 1221 connected to the ASIC 1216 receive an operation input from the operator and transmit the operation input information received by the ASIC 1216.

  The power supply voltage control program executed by the MFP according to the embodiment is provided by being incorporated in advance in a ROM or the like.

  The power supply voltage control program executed by the image forming apparatus according to the embodiment is a file in an installable or executable format, such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk), or the like. It may be configured to be recorded on a computer-readable recording medium.

  Furthermore, the power supply voltage control program executed by the MFP according to the embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network.

  The power supply voltage control program executed by the MFP according to the embodiment has a module configuration including the above-described units associated with image reading execution and image formation. As actual hardware, a CPU (processor) supplies power from the ROM. By reading and executing the voltage control program, each function of the power supply voltage control is generated on the main storage device.

  As described above, the power supply voltage control apparatus, the power supply voltage control method, the program for causing the computer to execute the method, and the image forming apparatus according to the present invention are useful for the power supply voltage control technology, and in particular, the power supply in the image forming apparatus. Suitable for voltage control technology.

2 is a functional block diagram of the power supply voltage control apparatus according to Embodiment 1. FIG. It is a table which shows the pattern of the soft start corresponding to a voltage fluctuation value. It is a time chart which shows the pattern of the soft start corresponding to the table which a drive control part uses. 4 is a flowchart illustrating a procedure of input power supply voltage control according to the first embodiment. It is a flowchart explaining the procedure in which a drive control part selects the pattern of a soft start by threshold value position determination. FIG. 6 is a diagram illustrating an image forming operation of the image forming apparatus. FIG. 5 is a functional block diagram of a power supply voltage control apparatus according to a second embodiment. It is a time chart which shows an example of the PWM control which a drive control part performs with respect to an AC motor. FIG. 10 is a circuit diagram illustrating a main part of a power supply voltage control device according to a third embodiment. FIG. 10 is a functional block diagram of a power supply voltage control device according to a fourth embodiment. 2 is a block diagram illustrating a hardware configuration of an image forming apparatus in which the power supply voltage control apparatus according to Embodiment 1 is incorporated. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Input part 3 Drive control part 4 Fixing part 5 Main heater 6 Sub heater 7 Main heater control part 8 Rectification charge part 9 Charge / discharge switching part 10 Electric double layer capacitor 11 Voltage detection part 12 Input voltage current detection part 13 Input power Calculation unit 14 Power supply unit

Claims (20)

Voltage detecting means for detecting an input voltage from an AC power source;
A voltage drop amount detection means for detecting a voltage drop amount from the voltage detected by the voltage detection means when driving a load;
A comparison means for comparing the voltage drop detected by the voltage drop detection with a predetermined threshold;
Voltage control means for performing a voltage control process for reducing the voltage drop amount by controlling the current flowing to the load when the voltage drop amount compared by the comparison means is greater than a predetermined threshold;
A power supply voltage control apparatus comprising:   When the load is a heater, the voltage control means performs a soft start process on the load to suppress an inrush current and reduce the voltage drop amount by changing a phase width and a maximum value of a current to the heater. The power supply voltage control apparatus according to claim 1, wherein the power supply voltage control apparatus is applied.   The said voltage control means performs the process which suppresses an inrush current by changing the phase width and maximum value of the electric current to the said AC motor, when the said load is an AC motor. Or the power supply voltage control apparatus of 2.   The voltage detecting means detects a voltage by detecting a DC voltage by a photocoupler whose output changes linearly by a change in an input AC voltage and a photoelectric element that generates a current by irradiation from the photocoupler. The power supply voltage control apparatus according to any one of claims 1 to 3. Rectifying means for converting AC current input from the AC power source into DC current;
Power storage means for storing the DC current converted by the rectifying means;
Charge / discharge means for charging and discharging the power storage means;
Input power calculating means for calculating the power of the input AC current;
Further comprising
The voltage control means performs the voltage control process by charging the power storage means when the input power calculated by the input power calculation means exceeds a predetermined threshold value. Item 5. The power supply voltage control device according to any one of Items 1 to 4.   The voltage control means performs the voltage control process by discharging the power storage means when the input power calculated by the input power calculation means does not exceed a predetermined threshold value. The power supply voltage control apparatus according to claim 5.   The voltage control means suppresses an inrush current by changing a phase width and a maximum value of a current on the primary side of the rectifying means, converts the current into a DC current, and stores the electric storage means by the rectified current. The power supply voltage control apparatus according to claim 5, wherein the power supply voltage control apparatus is a power supply voltage control apparatus.   The power supply voltage control apparatus according to claim 5, wherein the power storage unit is an electric double layer capacitor. A power supply voltage control method in a power supply voltage control device,
A voltage detection step of detecting an input voltage from the AC power source by the voltage detection means;
A voltage drop amount detection step of detecting a voltage drop amount from the voltage detected in the voltage detection step when the load is driven by the voltage drop amount detection means;
A comparison step of comparing the voltage drop detected in the voltage drop detection step with a predetermined threshold by a comparison means;
A voltage control step of performing a voltage control process for reducing the voltage drop amount by controlling the current flowing to the load when the voltage drop amount compared in the comparison step is larger than a predetermined threshold by the voltage control unit;
A power supply voltage control method.   In the voltage control step, when the load is a heater, a soft start process is performed on the load to suppress an inrush current by changing a phase width and a maximum value of a current to the heater and to reduce the voltage drop amount. The power supply voltage control method according to claim 9, wherein the power supply voltage control method is performed.   10. The voltage control step performs processing for suppressing an inrush current by changing a phase width and a maximum value of a current to the AC motor when the load is an AC motor. Or the power supply voltage control method according to 10.   The voltage detecting step detects the voltage by detecting a DC voltage by a photocoupler whose output changes linearly according to a change in input AC voltage, and a photoelectric element that generates a current by irradiation from the photocoupler. The power supply voltage control method according to any one of claims 9 to 11. A rectifying step of converting an AC current input from the AC power source into a DC current by a rectifying means;
A power storage step of storing the DC current converted in the rectification step by a power storage means;
A charge / discharge step of charging and discharging the power storage means by the charge / discharge means;
An input power calculation step of calculating the power of the input AC current by an input power calculation means;
Further including
The voltage control step performs the voltage control process by charging in the power storage step when the input power calculated in the input power calculation step exceeds a predetermined threshold value. Item 13. The power supply voltage control method according to any one of Items 9 to 12.   In the voltage control step, when the input power calculated in the input power calculation step does not exceed a predetermined threshold value, the voltage control process is performed by discharging the power storage means. The power supply voltage control method according to claim 13.   The voltage control step suppresses an inrush current by changing a phase width and a maximum value of a primary side current of the rectifying means, converts the current into a DC current, and stores the electric current in the power storage step by the rectified current. The power supply voltage control method according to claim 13 or 14, wherein the power supply voltage control method is one.   The power storage voltage control method according to any one of claims 13 to 15, wherein the power storage step stores power in an electric double layer capacitor.   A program causing a computer to execute the power supply voltage control method according to any one of claims 9 to 16. Drive means for driving a transfer body, visible image forming means for forming an electrostatic latent image on a photoconductor according to image data, forming a visible image from the electrostatic latent image, and transferring the image to the transfer body; and the drive means Drive control means for controlling, image output means for transferring the visible image on the transfer member driven by the drive means to a recording medium, the drive means, visible image forming means, drive control means, and image output means A power supply means for supplying power to the image forming apparatus,
The power source means
Voltage detecting means for detecting an input voltage from an AC power source;
A voltage drop amount detection means for detecting a voltage drop amount from the voltage detected by the voltage detection means when driving a load;
A comparison means for comparing the voltage drop detected by the voltage drop detection with a predetermined threshold;
Voltage control means for performing a voltage control process for reducing the voltage drop amount by controlling the current flowing to the load when the voltage drop amount compared by the comparison means is greater than a predetermined threshold;
An image forming apparatus comprising:   When the load is a heater, the voltage control means performs a soft start process on the load to suppress an inrush current by changing a phase width and a maximum value of a current to the heater and to reduce the voltage drop amount. The image forming apparatus according to claim 18, wherein the image forming apparatus is applied.   When the load is an AC motor, the voltage control means performs a soft start process on the load to suppress an inrush current by changing a phase width and a maximum value of a current to the heater and to reduce the voltage drop amount. 20. The image forming apparatus according to claim 18, wherein the image forming apparatus is applied.

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