JP2009017724A - Power supply unit, image forming apparatus, postprocessor and power supply method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply unit capable of improving energy efficiency without causing fault in operation of a load, and to provide an image forming apparatus, a postprocessor and a power supply method. <P>SOLUTION: The power supply unit 100 is provided with a constant voltage power supply 110 for supplying power to a load M; an electric double-layer capacitor 120 connected between the constant voltage power supply 110 and the load M, charged by the power supplied from the constant voltage power supply 110 and supplying the charged power to the load M; and a control section 130 for converting a voltage value outputted from the constant voltage power supply 110 into a voltage value having the minimum operation voltage value of the load M as a lower limit value depending on the operation state of the load M or the operation state of the electric double-layer capacitor 120. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply apparatus, an image forming apparatus, a post-processing apparatus, and a power supply method.

  In recent years, an image forming apparatus that forms an image on a paper while conveying paper such as a copying machine, a printer, and a facsimile, and a post-processing device that performs post-processing on the paper include a transport motor and each mechanism for transporting the paper. A plurality of loads that consume a large peak power when driving a drive motor or the like to be driven are provided.

  A main power supply (mainly a constant voltage power supply) that supplies power to such a load must secure an output capacity corresponding to the peak power of each load, resulting in an increase in power supply size and cost. It was.

  In order to solve the above problem, there is a technique of providing a power storage device such as a secondary battery or an electric double layer capacitor to assist the main power source when peak power is consumed. For example, a technology for supplying power with a configuration such as a constant voltage power source, a charging circuit connected to the constant voltage power source, a capacitor connected to the charging circuit, a discharging circuit connected to the capacitor, and a load connected to the discharging circuit. There is.

As another example, in a power supply apparatus that charges a power storage device such as a secondary battery or an electric double layer capacitor with a DC voltage output of a power generator such as a fuel cell, and supplies power to a variable load via a constant voltage power supply. In order to enable a stable voltage to be supplied to the load even under sudden load fluctuations, a power generator that sets the output voltage lower than the maximum power consumption of the load and larger than a predetermined power consumption during the operation of the load; When the power consumption of the power storage device (secondary battery or electric double layer capacitor) connected in parallel with the power generation device and the load is greater than the predetermined power consumption of the load, power is supplied to the load by discharging the power storage device. A control unit that controls power supply from the power generator to the load and charging of the power storage device when the power consumption of the load is equal to or lower than the predetermined power consumption of the load. Power device is disclosed (see Patent Document 1).
Japanese Patent Laid-Open No. 2006-166577

  However, if the configuration is a constant voltage power supply, a charging circuit connected to the constant voltage power supply, a capacitor connected to the charging circuit, a discharging circuit connected to the capacitor, a load connected to the discharging circuit, the configuration It is complicated and incurs a cost increase. Furthermore, when the internal impedance of the capacitor is larger than the output impedance on the charging circuit side, the power supplied to the load via the discharging circuit exceeds that on the charging circuit side, and the stored energy of the capacitor cannot be fully utilized. It will be. A capacitor having a smaller capacity has a larger internal impedance. To avoid this problem, a capacitor having a larger capacity must be used unnecessarily, resulting in a problem of increasing the size and cost. .

  Further, as in Patent Document 1, when a power storage device is combined with a power generation device having a high output impedance for auxiliary use with high power, the voltage drop due to the internal impedance of the power storage device is large, so the voltage supplied to the load is the lowest. It may become lower than the operating voltage and cause malfunction. For example, when the load is a motor, there arises a problem that the number of rotations decreases or the motor stops due to insufficient torque.

  In view of the above problems, an object of the present invention is to realize a power supply device, an image forming apparatus, a post-processing apparatus, and a power supply method that can improve energy efficiency without causing load malfunction.

  According to the first aspect of the present invention, the constant voltage power supply means for supplying power to the load, and connected between the constant voltage power supply means and the load, are charged by the power supply from the constant voltage power supply, An electric double layer capacitor for supplying charged power to the load, and a voltage value output from the constant voltage power supply means in accordance with the operating state of the load or the operating state of the electric double layer capacitor, the lowest operation of the load And a control means for changing the voltage value to a voltage value having a lower limit.

  According to a second aspect of the present invention, in the power supply device according to the first aspect, when the load is driven, the control means is output from the constant voltage power supply means at a timing before driving the load. The voltage value is changed to a voltage value with the minimum operating voltage value of the load as a lower limit.

  According to a third aspect of the present invention, in the power supply device according to the first or second aspect, when the charging of the electric double layer capacitor is completed, the control unit is configured to perform the charging after the electric double layer capacitor has been charged. At the timing, the voltage value output from the constant voltage power supply means is changed to a voltage value having the lowest operating voltage value of the load as a lower limit.

  According to a fourth aspect of the present invention, in the power supply device according to any one of the first to third aspects, the control unit is configured to output a voltage value at which the operating state of the load is output from the constant voltage power source unit. When the state before the change is returned, the voltage value output from the constant voltage power supply means is returned to the voltage value before the change.

  According to a fifth aspect of the present invention, in the power supply device according to any one of the first to third aspects, the power supply device further includes a time measuring unit that measures a preset time after the load is driven, The control means returns the voltage value output from the constant voltage power supply means to the voltage value before being changed when the preset time is measured by the time measuring means.

  According to a sixth aspect of the present invention, in an image forming apparatus comprising an image forming means for forming an image on a sheet, the image forming apparatus comprising the power supply device according to any one of the first to fifth aspects. Provided.

  According to the invention described in claim 7, a post-processing apparatus including a post-processing unit that performs post-processing on a sheet is provided. The post-processing apparatus including the power supply device according to claim 1 is provided. Is done.

  According to invention of Claim 8, it connects between the constant voltage power supply means which supplies electric power to load, the said constant voltage power supply means, and the said load, and is charged by the electric power supply from the said constant voltage power supply, In the power supply method for controlling the power supply to the load by controlling the electric double layer capacitor that supplies the charged power to the load, depending on the operating state of the load or the operating state of the electric double layer capacitor There is provided a power supply method for changing a voltage value output from the constant voltage power supply means to a voltage value having a minimum operating voltage value of the load as a lower limit.

  According to the ninth aspect of the present invention, in the power supply method according to the eighth aspect, when the load is driven, the voltage value output from the constant voltage power source means at a timing before the load is driven. The voltage is changed to a voltage value having the minimum operating voltage value of the load as a lower limit.

  According to a tenth aspect of the present invention, in the power supply method according to the eighth or ninth aspect, when the charging of the electric double layer capacitor is completed, the determination is made at a timing after the charging of the electric double layer capacitor is completed. The voltage value output from the voltage power supply means is changed to a voltage value having the minimum operating voltage value of the load as a lower limit.

  According to an eleventh aspect of the present invention, in the power supply method according to any one of the eighth to tenth aspects, the voltage value output from the constant voltage power supply means is changed as the operating state of the load. When returning to the previous state, the voltage value output from the constant voltage power supply means is returned to the voltage value before the change.

  According to a twelfth aspect of the present invention, in the power supply method according to any one of the eighth to eleventh aspects, the preset time is measured after the load is driven, and the time measuring means performs the pre- When the set time is counted, the voltage value output from the constant voltage power supply means is returned to the voltage value before being changed.

  According to the first and eighth aspects of the invention, the voltage value output from the constant voltage power supply means is set to the lower limit of the minimum operating voltage value of the load according to the operating state of the load or the operating state of the electric double layer capacitor. Since the voltage can be changed to the voltage value to be supplied, insufficient power is supplied from the electric double layer capacitor while maintaining the operation of the load, and the energy efficiency can be improved without causing a malfunction of the load.

  According to the second and ninth aspects of the invention, the same effects as those of the first and eighth aspects can be obtained. When the load is driven, the constant voltage power supply means supplies the power supply with the minimum operating voltage value. Is supplied, and insufficient electric power is supplied by the electric double layer capacitor, so that it is possible to prevent malfunction of the load.

  According to the third and tenth aspects of the invention, the same effect as that of the first, second, eighth or ninth aspect can be obtained, and when charging of the electric double layer capacitor is completed, a constant voltage is obtained. Since power is supplied from the power source means to the load at the minimum operating voltage value, and insufficient power is supplied to the load by the electric double layer capacitor, it is possible to prevent malfunction of the load and The energy of the multilayer capacitor can be used effectively.

  According to the invention described in claims 4 and 11, it is possible to obtain the same effect as any one of claims 1 to 3 and 8 to 10, and there is no possibility of causing a malfunction of the load. Therefore, it is possible to stably charge the electric double layer capacitor and to prepare power corresponding to the change in the next operation state of the load, so that the malfunction of the load can be prevented.

  According to the fifth and twelfth aspects of the present invention, the same effect as any one of the first to third and eighth to tenth aspects can be obtained, and the preset value is set after the load is driven. During the consumption time of the peak power that occurs in time, it is possible to prevent malfunction of the load due to the power supply assistance by the electric double layer capacitor, that is, the period during which the power supply assistance by the electric double layer capacitor is not necessary, that is, constant voltage During periods when there is no risk of load malfunction due to power supply from the power supply, the electric double layer capacitor can be stably charged, and power is prepared for the next change in the operating state of the load. Therefore, it is possible to prevent malfunction of the load.

  According to the invention described in claim 6, the same effect as the power supply device described in any one of claims 1 to 5 can be obtained.

  According to the seventh aspect of the present invention, the same effect as the power supply device according to any one of the first to fifth aspects can be obtained.

[Embodiment 1]
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.
First, the configuration will be described.
FIG. 1 is a schematic cross-sectional configuration diagram of an image forming system A according to the first embodiment.

  As shown in FIG. 1, the image forming system A reads an image from a document, forms an image on the paper P, receives image data from an operation device or the like, and receives an image based on the received image data. This is a digital multi-function peripheral that includes an image forming apparatus 1 that forms on a sheet P, and a post-processing apparatus 2 that performs post-processing such as punching, stapling, and folding on a sheet on which an image is formed.

  As shown in FIG. 1, the image forming apparatus 1 includes an image reading unit 10 and a printing unit 20, and the post-processing device 2 includes a staple unit 30 and a folding unit 40.

  The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder) and a reading unit 12. The document d placed on the document tray T1 of the automatic document feeder 11 is conveyed to a contact glass that is a reading portion of the reading unit 12, and an image on one or both sides of the document d is read by the optical system of the reading unit 12. The image of the document d is read by a CCD (Charge Coupled Device). Here, the image means not only image data such as graphics and photographs but also text data such as characters and symbols.

  An image (analog image signal) read by the reading unit 12 is output to an image control unit (not shown), subjected to A / D conversion and various image processing in the image control unit, and then output to the printing unit 20. The

  The printing unit 20 performs electrophotographic image forming processing based on input print data, and includes a paper feeding unit 21, a paper feeding conveyance unit 22, an image forming unit 23, and a carry-out unit 24. Is done.

  The paper feed unit 21 includes a plurality of paper feed cassettes 21a, paper feed means 21b, a manual feed tray T2, and the like. The paper feed cassette 21a stores paper P identified in advance for each size and type for each paper feed cassette 21a. The paper feed means 21b directs the paper P from the top to the paper feed conveyance unit 22 one by one. Transport. The manual feed tray T2 can stack various types of paper P according to the user's needs, and transports the paper P stacked by the paper feed rollers one by one from the top to the paper feed transport unit 22. To do.

  The paper feeding / conveying unit 22 conveys the paper P conveyed from the paper feeding cassette 21a or the manual feed tray T2 to the transfer device 23a via a plurality of intermediate rollers, registration rollers 22a, and the like.

  The image forming unit 23 includes a photosensitive drum, a charging device, a laser output unit that outputs laser light based on image data, and a polygon mirror that scans the laser light in the main scanning direction, a developing device, a transfer device 23a, A cleaning unit and a fixing device 23b are provided. Specifically, an electrostatic latent image is formed by irradiating a photosensitive drum charged by a charging device with laser light using an exposure device. The developing device develops the electrostatic latent image by attaching charged toner to the surface of the photosensitive drum on which the electrostatic latent image is formed. The toner image formed on the photosensitive drum by the developing device is transferred to the paper P by the transfer device 23a. Further, after the toner image is transferred to the paper P, residual toner on the surface of the photosensitive drum is removed by the cleaning unit.

  The fixing device 23 b thermally fixes the toner image transferred to the paper P conveyed by the paper feed conveyance unit 22. The fixed sheet P is sandwiched between the discharge rollers of the carry-out unit 24 and is conveyed from the carry-out port to the post-processing device 2.

The post-processing device 2 is a finisher that accumulates the paper P on which an image is formed by the image forming apparatus 1 for each copy, and performs post-processing such as stapling processing and folding processing for each copy.
As shown in FIG. 1, the post-processing apparatus 2 includes a fixed paper discharge tray T3 from which paper P is discharged, a lift paper discharge tray T4, a booklet tray T5, a staple unit 30, a folding unit 40, and a plurality of transport rollers. And a conveying means. Sheets that have been or have not been subjected to various processes are discharged to a fixed discharge tray T3.

  The staple unit 30 includes a stack base 31 and a stapler 32, and the paper P transported from the image forming apparatus 1 is width-aligned with the bundle of paper P transported to the stack base 31 by a plurality of transport rollers. A stapling process for binding with a binding needle is performed. The bundle of sheets P subjected to the stapling process is conveyed to the lifting / lowering discharge tray T4 or the folding unit 40.

  The folding unit 40 includes a stack base 41 and a movable stopper member 42, and performs folding processing such as half-folding processing, three-folding processing, and Z-folding processing on the paper P transported by a plurality of transport rollers. The folded paper P is discharged to the booklet tray T5.

  As shown in FIG. 1, the image forming apparatus 1 and the post-processing apparatus 2 included in the image forming system A have a large peak power during driving, such as a motor that drives a plurality of rollers and a motor that drives each mechanism. It has multiple loads to consume.

A control block diagram of the power supply apparatus 100 for supplying power to such a load is shown in FIG.
As shown in FIG. 2, the power supply device 100 includes a constant voltage power source 110, an electric double layer capacitor 120, a control unit 130, an anode to the constant voltage power source 110, a cathode to one terminal of a load M, and an electric double layer capacitor 120. Each terminal is provided with a diode 140 connected thereto.

As shown in FIG. 2, a voltage value output from the constant voltage power supply 110 is a power supply voltage Vd, and a supplied current value is a power supply current Id. The electric double layer capacitor 120 has a capacitance C and an internal impedance Zc. The voltage value (load applied voltage value) of the electric double layer capacitor is a capacitor voltage Vc, and the current value is a capacitor current Ic. The current value supplied to the load M is defined as a load current IL (= Id + Ic).
Actually, a forward voltage Vf is generated across the diode. For example, in the case of a Schottky barrier diode, it is around 0.4 [V], and in the case of a general diode, it is around 1.0 to 2.0 [V]. However, for convenience of explanation, Vf = 0 is assumed hereinafter.

  The constant voltage power supply 110 is a power supply that maintains a power supply voltage that is output in accordance with an instruction from the control unit 130 at a constant voltage value, and is a constant voltage power supply unit that supplies power to a load M that consumes peak power.

  The electric double layer capacitor 120 is an electric storage device using an electric double layer phenomenon in which electric charges are accumulated on the boundary surface between a solid electrode (for example, activated carbon) and an electrolytic solution, and is connected between a constant voltage power supply 110 and a load M. Then, it is charged by supplying power from the constant voltage power supply 110, and the charged power is supplied to the load M.

  The control unit 130 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a nonvolatile RAM, and the like. Programs and data stored in the ROM and the nonvolatile RAM are temporarily stored in the RAM and the like. Various information is exchanged with a main body control unit (not shown) that expands in a storage area (not shown) and controls the power supply apparatus 100 based on the program and controls the image forming apparatus 1 or the post-processing apparatus 2. Are connected so as to be able to transmit and receive, and receives the drive instruction information of the load M from the main body control unit, judges the received information, and controls the power supply processing to the load M.

  In the power supply process executed by the control unit 130 in the first embodiment, when the operation state of the load M is driven, or the operation state of the electric double layer capacitor 120 is charged, the timing before driving the load M, or The voltage value (power supply voltage Vd) output from the constant voltage power supply 110 is changed at the timing after the electric double layer capacitor 120 is fully charged, and the voltage value output from the constant voltage power supply 110 is changed as the operating state of the load M changes. Functioning as a control means for returning the voltage value (power supply voltage Vd) output from the constant voltage power supply 110 to the voltage value before being changed when returning to a state before being changed (for example, stopped state). A voltage instruction signal Sv for instructing to change Vd is output to the constant voltage power source 110, and the load is driven (ON) to a drive circuit included in the load M according to an instruction from the main body control unit And it outputs the drive signal Sm to instruct stop (OFF).

  The voltage value after the change is a value having the minimum operating voltage value Vd1 of the load M as a lower limit, and is set in advance to a value equal to or lower than the charging voltage value of the electric double layer capacitor 120.

  The load M is a load that consumes peak power. For example, in the image forming apparatus 1, a motor that drives various rollers constituting the paper feeding unit 21 b and the paper feeding / conveying unit 22 can be cited. In the post-processing apparatus 2, a motor that drives a conveyance roller that conveys a sheet to each unit, a motor that drives a stapler 32 of the staple unit 30, and the like can be given.

Next, the operation of the first embodiment will be described.
FIG. 3 shows a flowchart of the power supply process in the first embodiment.
3 is executed by the control unit 130 of the power supply device 100 in cooperation with each unit of the power supply device 100 based on an instruction input from the main body control unit. The load M will be described by taking a motor that drives the stapler 32 as an example.

  First, whether or not initial charging of the electric double layer capacitor 120 is incomplete when the constant voltage power supply 110 is in a state where the power supply voltage Vd is supplied to the electric double layer capacitor 120 at the rated voltage value Vd0 of the load M. Is determined (step S1).

  When the initial charging of the electric double layer capacitor 120 is completed (step S1; No), the process proceeds to step S4.

  When the initial charging of the electric double layer capacitor 120 is not completed (step S1; Yes), the initial charging of the electric double layer capacitor 120 is executed while the power supply voltage Vd holds the rated voltage value Vd0 of the load M. (Step S2).

  Then, it is determined whether or not the initial charging of the electric double layer capacitor 120 is completed (step S3). When the initial charging is not completed (step S3; No), the process returns to step S2.

  When the initial charging of the electric double layer capacitor 120 is completed (step S1; No or step S3; Yes), the power supply voltage Vd is set to the minimum operating voltage value Vd1 of the load M, and a voltage instruction indicating the voltage change instruction The signal Sv is output to the constant voltage power supply 110 (step S4). Then, it is determined whether printing has been started (step S5). Whether or not printing has started is determined based on, for example, whether or not a print start signal from the main body control unit has been input.

  If printing has not started (step S5; No), the process returns to step S5. When printing is started (step S5; Yes), it is determined whether or not there is an instruction to drive (turn on) the stapler 32 from the main body control unit (step S6). When there is no instruction to drive the stapler 32 (step S6; No), the process returns to step S6.

  When there is an instruction to drive the stapler 32 from the main body control unit (step S6; Yes), a drive signal Sm instructing driving (ON) is output to a driving circuit included in a load M (motor) that drives the stapler 32, and the load Electric power is supplied to M, and the stapler 32 is turned on (step S7).

  It is determined whether or not the stapling process has been completed (step S8). If the stapling process has not been completed (step S8; No), the process returns to step S8.

  When the stapling process is completed (step S8; Yes), the drive signal Sm instructing the drive stop (OFF) is output to the drive circuit included in the load M (motor) that drives the stapler 32, and power supply to the load M is performed. Stopped and the stapler 32 is turned off (step S9).

  When the power supply to the load M is stopped, the power supply voltage Vd is set to the rated voltage value Vd0 of the load M, the voltage instruction signal Sv indicating the voltage change instruction is output to the constant voltage power supply 110, and the power supply voltage Vd Is returned to the state before the change (step S4) (step S10), and it is determined whether or not the printing is completed (step S11). Whether or not printing has been completed is determined based on, for example, whether or not a print execution signal from the main body control unit is no longer input.

  If printing has not ended (step S11; No), it is determined whether or not there is an instruction to drive (turn on) the stapler 32 from the main body control unit (step S12). If there is no instruction to drive the stapler 32 (step S12; No), the process returns to step S12.

  When there is an instruction to drive the stapler 32 from the main body control unit (step S12; Yes), the power supply voltage Vd is set to the minimum operating voltage value Vd1 of the load M (step S13), and the process proceeds to step S7.

  When the printing is finished (step S11; Yes), this process is finished.

FIG. 4 shows an example of a timing chart of the power supply process in the first embodiment.
As shown in FIG. 4, first, when the initial charging of the electric double layer capacitor 120 is completed at time t0, the power supply voltage Vd is changed to the minimum operating voltage value Vd1 of the load M.

  At time t1, a drive signal Sm instructing driving (ON) is output to a driving circuit included in a load M (motor) that starts printing and drives the stapler 32. The constant voltage power supply 110 and the electric double layer capacitor are output to the load M. Electric power is supplied from 120, and a load current IL flows. The load current IL (= ILp) at this time is the sum of the power supply current Id (= Id1) supplied from the constant voltage power supply 110 and the capacitor current Ic (= Ic0) supplied from the electric double layer capacitor 120. In addition, the terminal voltage Vc of the electric double layer capacitor 120 at this time, that is, the voltage applied to the load M has a voltage drop due to the internal impedance Zc of the electric double layer capacitor 120 and the capacitor current Ic, and a voltage drop due to discharge. Although it occurs, it does not fall below the power supply voltage Vd1.

  Between the times t1 and t2, the load M is consuming peak power. The load current IL at this time is supplied from the power supply current Id supplied from the constant voltage power supply 110 and the electric double layer capacitor 120. And the capacitor current Ic.

  Between time t <b> 2 and t <b> 3, the load M is in a steady drive period, and power is supplied from the electric double layer capacitor 120.

  At time t3, the stapling process is completed, and a drive signal Sm instructing drive stop (OFF) is output to a drive circuit included in a load M (motor) that drives the stapler 32, and power supply to the load M is stopped. The load current IL does not flow.

  At time t4, the power supply voltage Vd is restored to the rated voltage value Vd0 of the load M, and charging of the electric double layer capacitor 120 starts to be started.

  Every time after the time t4, when printing has not been completed, every time a drive signal Sm instructing driving (ON) is output to the driving circuit provided in the load M (motor) that drives the stapler 32, the time t1 The state of t4 is repeated.

  As described above, according to the first embodiment, the power supply voltage Vd output from the constant voltage power supply 110 is set to the lowest operation voltage of the load M according to the operation state of the load M or the operation state of the electric double layer capacitor 120. Since it can be changed to a voltage value with the value Vd1 as the lower limit, insufficient power is supplied from the electric double layer capacitor 120 while maintaining the operation of the load M, and the energy efficiency is improved without causing malfunction of the load M Can be obtained.

  In particular, when charging of the electric double layer capacitor 120 is completed, electric power is supplied from the constant voltage power supply 110 to the load M at the minimum operating voltage value Vd1, and insufficient electric power is supplied to the load M by the electric double layer capacitor 120. Therefore, the malfunction of the load M can be prevented and the energy of the electric double layer capacitor 120 can be effectively used. Further, when the load M is being driven, power is supplied from the constant voltage power supply 110 at the minimum operating voltage value Vd1, and insufficient power is supplied by the electric double layer capacitor 120. It is possible to prevent malfunctions.

  Furthermore, when there is no risk of malfunction of the load M, the electric double layer capacitor 120 can be stably charged, and power can be prepared for the next change in the operating state of the load M. Therefore, it is possible to prevent malfunction of the load M.

[Embodiment 2]
Hereinafter, the second embodiment of the present invention will be described in detail.
Since the schematic cross-sectional configuration of the image forming system A in the second embodiment is the same as that in the first embodiment, illustration and description thereof are omitted.
Further, the control block diagram of the power supply device provided in the image forming apparatus 1 or the post-processing device 2 of the image forming system A in the second embodiment is the same as the control block diagram of the power supply device 100 in the first embodiment. Therefore, only different parts will be described and illustration is omitted.

  The control unit 130 according to the second embodiment includes a timer that realizes a function as a time measuring unit that measures a preset time (switching time Tc) after the load M is driven, and the operation state of the load M is When the driving or the operating state of the electric double layer capacitor 120 is complete charging, the voltage value output from the constant voltage power supply 110 at the timing before driving the load M or the timing after completion of charging the electric double layer capacitor 120 When (power supply voltage Vd) is changed and the switching time Tc is measured, it functions as a control means for returning the voltage value (power supply voltage Vd) output from the constant voltage power supply 110 to the voltage value before the change, A voltage instruction signal Sv for instructing to change the power supply voltage Vd is output to the constant voltage power supply 110, and in accordance with an instruction from the main body control unit, a negative voltage is applied to the drive circuit included in the load M. And outputs the drive signal Sm to instruct driving (ON) or stop (OFF) M.

  The switching time Tc is longer than the time required for the load current IL flowing when the load M consumes the peak power to pass the peak current value ILp, and is required until the driving of the load M is stopped. The time is set within the hour.

  The voltage value after the change is a value having the minimum operating voltage value of the load M as a lower limit, and is set in advance to a value equal to or lower than the charging voltage value of the electric double layer capacitor 120.

Next, the operation of the second embodiment will be described.
FIG. 5 shows a flowchart of the power supply process in the second embodiment.
5 is executed by the control unit 130 of the power supply apparatus 100 in cooperation with each unit of the power supply apparatus 100 based on an instruction input from the main body control unit. The load M will be described by taking a motor that drives the stapler 32 as an example.

  First, whether or not initial charging of the electric double layer capacitor 120 is incomplete when the constant voltage power supply 110 is in a state where the power supply voltage Vd is supplied to the electric double layer capacitor 120 at the rated voltage value Vd0 of the load M. Is determined (step S21).

  When the initial charging of the electric double layer capacitor 120 is completed (step S21; No), the process proceeds to step SS24.

  When the initial charging of the electric double layer capacitor 120 is not completed (step S21; Yes), the initial charging of the electric double layer capacitor 120 is executed with the power supply voltage Vd maintaining the rated voltage value Vd0 of the load M ( Step S22).

  And it is discriminate | determined whether the initial charge of the electric double layer capacitor 120 was completed (step S23), and when initial charge is incomplete (step S23; No), it returns to step S22.

  When the initial charging of the electric double layer capacitor 120 is completed (step S21; No, or step S23; Yes), the time T counted by the timer is cleared (T = 0) (step S24), and the power supply voltage Vd Is set to the minimum operating voltage value Vd1 of the load M, and the voltage instruction signal Sv indicating the voltage change instruction is output to the constant voltage power supply 110 (step S25). Then, it is determined whether printing has started (step S26). Whether or not printing has started is determined based on, for example, whether or not a print start signal from the main body control unit has been input.

  If printing has not started (step S26; No), the process returns to step S26. When printing is started (step S26; Yes), it is determined whether or not there is an instruction to drive (turn on) the stapler 32 from the main body control unit (step S27). If there is no instruction to drive the stapler 32 (step S27; No), the process returns to step S27.

  When there is an instruction to drive the stapler 32 from the main body control unit (step S27; Yes), a drive signal Sm instructing driving (ON) is output to a driving circuit included in a load M (motor) that drives the stapler 32, and the load Electric power is supplied to M, and the stapler 32 is turned on (step S28). Further, when the drive signal Sm is output, time measurement by a timer is started (step S29).

  It is determined whether or not the time measured by the timer T is greater than the switching time Tc (step S30). If the time measured by the timer T is equal to or shorter than the switching time Tc (step S30; No), the process returns to step S30.

  When the time measured by the timer T is longer than the switching time Tc (step S30; Yes), the power supply voltage Vd is set to the rated voltage value Vd0 of the load M, and the voltage instruction signal Sv indicating the voltage change instruction is the constant voltage power supply 110. To the state before the power supply voltage Vd is changed (step S25) (step S31), the time measurement by the timer is stopped, and the time measurement time T is cleared (step S32).

  Then, it is determined whether or not the stapling process is completed (step S33). If the stapling process is not completed (step S33; No), the process returns to step S33.

  When the stapling process is completed (step S33; Yes), the drive signal Sm instructing the drive stop (OFF) is output to the drive circuit included in the load M (motor) that drives the stapler 32, and power supply to the load M is performed. Stopped and the stapler 32 is turned off (step S34).

  When the power supply to the load M is stopped, it is determined whether or not the printing is finished (step S35). Whether or not printing has been completed is determined based on, for example, whether or not a print execution signal from the main body control unit is no longer input.

  If printing has not been completed (step S35; No), it is determined whether or not there is an instruction to drive (turn on) the stapler 32 from the main body control unit (step S36). If there is no instruction to drive the stapler 32 (step S36; No), the process returns to step S36.

  If there is an instruction to drive the stapler 32 from the main body control unit (step S36; Yes), the power supply voltage Vd is set to the minimum operating voltage value Vd1 of the load M (step S37), and the process proceeds to step S28.

  When the printing is finished (step S35; Yes), this process is finished.

  As described above, according to the second embodiment, the power supply voltage Vd output from the constant voltage power supply 110 is changed to the lowest operation voltage of the load M according to the operation state of the load M or the operation state of the electric double layer capacitor 120. Since it can be changed to a voltage value with the value Vd1 as the lower limit, insufficient power is supplied from the electric double layer capacitor 120 while maintaining the operation of the load M, and the energy efficiency is improved without causing malfunction of the load M Can be obtained.

  In particular, when charging of the electric double layer capacitor 120 is completed, electric power is supplied from the constant voltage power supply 110 to the load M at the minimum operating voltage value Vd1, and insufficient electric power is supplied to the load M by the electric double layer capacitor 120. Therefore, the malfunction of the load M can be prevented and the energy of the electric double layer capacitor 120 can be effectively used. Further, when the load M is being driven, power is supplied from the constant voltage power supply 110 at the minimum operating voltage value Vd1, and insufficient power is supplied by the electric double layer capacitor 120. It is possible to prevent malfunctions.

  Further, while the peak power generated within the switching time Tc after the load M is driven is consumed, it is possible to prevent the malfunction of the load M due to the power supply assistance by the electric double layer capacitor 120, and the electric double layer The electric double layer capacitor 120 is stably charged during a period when power supply assistance by the capacitor 120 is not necessary, that is, during a steady drive period during which there is no possibility of malfunction of the load M caused by power supply from the constant voltage power supply 110. Since the power corresponding to the next change in the operating state of the load M can be prepared, malfunction of the load M can be prevented.

  The present invention is not limited to the contents of the first and second embodiments, and can be appropriately changed without departing from the gist of the present invention.

1 is a schematic cross-sectional configuration diagram of an image forming system in Embodiment 1. FIG. It is a control block diagram of a power supply device. 3 is a flowchart of power supply processing in the first embodiment. 6 is a diagram illustrating an example of a timing chart of power supply processing according to Embodiment 1. FIG. It is a flowchart of the electric power supply process in this Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Post-processing apparatus 10 Image reading part 11 Automatic document feeding part 12 Reading part 20 Printing part 21 Paper feeding part 21a Paper feeding cassette 21b Paper feeding means 22 Paper feeding conveyance part 22a Registration roller 23 Image forming part 23a Transfer device 23b Fixing device 24 Unloading section 30 Staple unit 31 Stack base 32 Stapler 40 Folding unit 41 Stack base 42 Movable stopper member 100 Power supply device 110 Constant voltage power supply 120 Electric double layer capacitor 130 Control section 140 Diode A Image forming system C Capacitance d Document Ic Capacitor current Id Power supply current IL Load current M Load P Paper Sm Drive signal Sv Voltage instruction signal T1 Document tray T2 Manual feed tray T3 Fixed discharge tray T4 Lifting discharge tray T5 Booklet tray Tc Switching time Vc Capacitor voltage Vd Power supply voltage V 0 rated voltage value Vd1 the minimum operating voltage value Zc internal impedance

Claims (12)

Constant voltage power supply means for supplying power to the load;
An electric double layer capacitor connected between the constant voltage power supply means and the load, charged by power supply from the constant voltage power supply, and supplying the charged power to the load;
Control means for changing a voltage value output from the constant voltage power supply means to a voltage value having a minimum operating voltage value of the load as a lower limit in accordance with an operating state of the load or an operating state of the electric double layer capacitor;
A power supply device comprising: The control means includes
When the load is driven, the voltage value output from the constant voltage power supply means at a timing before driving the load is changed to a voltage value having the lowest operating voltage value of the load as a lower limit.
The power supply device according to claim 1. The control means includes
When charging of the electric double layer capacitor is completed, the voltage value output from the constant voltage power supply means at a timing after completion of charging of the electric double layer capacitor is set to a voltage value with the lowest operating voltage value of the load as a lower limit. change,
The power supply device according to claim 1 or 2. The control means includes
When the operating state of the load returns to the state before the voltage value output from the constant voltage power supply means is changed, the voltage value output from the constant voltage power supply means is returned to the voltage value before the change. ,
The power supply device according to any one of claims 1 to 3. Having time measuring means for measuring a preset time after the load is driven;
The control means includes
When the preset time is timed by the time measuring means, the voltage value output from the constant voltage power supply means is returned to the voltage value before being changed,
The power supply device according to any one of claims 1 to 3. In an image forming apparatus including an image forming unit that forms an image on paper,
An image forming apparatus comprising the power supply device according to claim 1. In a post-processing apparatus provided with post-processing means for performing post-processing on paper,
The post-processing apparatus provided with the power supply device as described in any one of Claim 1 to 5. A constant voltage power supply means for supplying power to a load; and an electricity connected between the constant voltage power supply means and the load, charged by power supply from the constant voltage power supply, and supplying the charged power to the load In the power supply method for controlling the power supply to the load by controlling the double layer capacitor,
Changing the voltage value output from the constant voltage power supply means to a voltage value having a minimum operating voltage value of the load as a lower limit in accordance with an operating state of a load or an operating state of the electric double layer capacitor;
Power supply method. When the load is driven, the voltage value output from the constant voltage power supply means at a timing before driving the load is changed to a voltage value having the lowest operating voltage value of the load as a lower limit.
The power supply method according to claim 8. When charging of the electric double layer capacitor is completed, the voltage value output from the constant voltage power supply means at a timing after completion of charging of the electric double layer capacitor is set to a voltage value with the lowest operating voltage value of the load as a lower limit. change,
The power supply method according to claim 8 or 9. When the operating state of the load returns to the state before the voltage value output from the constant voltage power supply means is changed, the voltage value output from the constant voltage power supply means is returned to the voltage value before the change. ,
The power supply method according to any one of claims 8 to 10. Time a preset time after the load is driven,
When the preset time is timed by the time measuring means, the voltage value output from the constant voltage power supply means is returned to the voltage value before being changed,
The power supply method according to any one of claims 8 to 11.

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