JP2007033752A - Charging and discharging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging and discharging system capable of quickly charging a capacitor supplying electric power to a load, without increasing the power supply capacity. <P>SOLUTION: The charging and discharging system 50 has a precharging capacitor C1 which is selectively charged and discharged with the electric power from a charging power source 51; a control part 55 which discharge the precharging capacitor C1 to charge a capacitor C3, when a capacitor C3 to be discharged to the load 72 is connected to a capacitor C3 in a mechatronics circuit 70; and switches SW1 and SW2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer using an electrophotographic system, and more particularly to a charge / discharge system that assists power supply to a load such as a heating device that fixes a toner image on a recording sheet or the like.

  An image forming apparatus such as a copying machine or a printer forms an image on a recording medium such as plain paper or OHP. In such an image forming apparatus, an electrophotographic system is often employed from the viewpoint of speeding up image formation, improving image quality, and reducing costs. The electrophotographic method is a method in which a toner image is formed on a recording medium, and the formed toner image is fixed on the recording medium with heat and pressure. As a fixing method, a heat roller method is generally adopted. The heat roller is most often a heating element such as a halogen heater or a ceramic heater, and a recording medium having a toner image transferred to a portion called a nip formed by press-contacting the heat roller and the pressure roller is used. By passing the toner image, the toner image is fixed on the recording medium.

  In addition, a power supply device that supplies power to a mechatronics system (motor, CPU, relay, or other electronic device or a device that performs charging, development, transfer, or the like) in the image forming apparatus is used. In an image forming apparatus such as a copying machine or a printer, the power for overheating a fixing device that fixes toner onto a recording medium is proportional to the number of recording media discharged from the image forming apparatus (the number of discharged sheets per minute). Increase.

In response to this increase in power, there are techniques described in Patent Documents 1 and 2. For example, in Patent Document 1, an electric double layer capacitor is provided as a power source for the heat roller, the electric double layer capacitor is charged before the operation of the heat roller, and from both the electric double layer capacitor and the power source before the operation is resumed. Techniques for supplying power to the heat roller have been proposed.
Japanese Patent No. 3588006 JP-A-11-98710

  However, charging a secondary battery such as an electric double layer capacitor, a lead storage battery, a lithium ion battery, or a nickel cadmium battery requires a certain amount of time. Therefore, in order to quickly supply power to a load, the charging time is shortened. It has become an issue.

  The charging time depends on the capacity of the power supply in addition to the capacity of the medium for storing energy. For example, if the charging voltage is 100 V and the charging current is 10 A, 100 V × 10 A = 1000 W, so that it takes one hour to store 1000 Wh of energy. On the other hand, if the charging voltage is 100 V and the charging current is 5 times 50 A, then 100 V × 50 A = 5000 W, so that it takes only 0.2 hours (12 minutes) to store 1000 Wh of energy.

  That is, if the power source capacity is increased, the charging time can be shortened. However, increasing the power supply capacity leads to an increase in the size of the apparatus and a large-scale power facility, resulting in an uneconomical operation rate.

  The present invention has been made to solve the above-described conventional problems, and provides a charge / discharge system capable of rapidly charging a capacitor that supplies power to a load without increasing the power capacity. Is.

  The present invention is a charge / discharge system for assisting power supply to a load in an image forming apparatus, wherein a first capacitor that selectively performs charging and discharging by power from a power source, and discharging the load. Control means for discharging the first capacitor and charging the second capacitor when the second capacitor to be performed is connected to the first capacitor.

  With this configuration, the second battery that supplies power to the load by discharging is not charged directly by the power supply, but is rapidly charged by discharging the first battery previously charged by the power supply. . Therefore, when the load is driven, the second battery can be charged rapidly without depending on the capacity of the power source.

  In the charging / discharging system of the present invention, the control unit includes a detection unit that detects a charging state of the first capacitor, and the detection unit detects that the first capacitor is not fully charged. In this case, the first capacitor is charged, and when it is detected that the first capacitor is fully charged, the first capacitor is discharged and the second capacitor is charged.

  With this configuration, it is possible to appropriately charge the first capacitor and prepare for the charging of the second capacitor.

  In the charging / discharging system of the present invention, the control means includes timer means for setting a time zone, and the timer means is charged in the time zone set by the timer means. In the time zone other than the time zone set by the above, the first battery is discharged and the second battery is charged.

  With this configuration, for example, the first capacitor is charged at night time when the device incorporating the load does not operate, and before the operation of the device incorporating the load is resumed, the charged first capacitor is discharged by The second battery can be rapidly charged without depending on the capacity of the power source.

  In the charging / discharging system of the present invention, the control means charges the first capacitor after the operation of the device incorporating the load is completed, and before or simultaneously with the resumption of operation of the device incorporating the load. The first capacitor is discharged to charge the second capacitor.

  With this configuration, the first capacitor is charged while the device incorporating the load is not operating, and before the operation of the device incorporating the load is resumed, the charged first capacitor is discharged to the capacity of the power source. It is possible to charge the second battery quickly without depending on it.

  In the charging / discharging system of the present invention, the control means includes a first switch provided between the power source and the first capacitor, and the first capacitor is charged when the first capacitor is charged. The first switch is turned on when the first capacitor is discharged to discharge the first capacitor and charge the second capacitor.

  In the charging / discharging system of the present invention, the first switch includes a first switch circuit connected to one end of the power supply, and a second switch circuit connected to the other end of the power supply.

  In the charging / discharging system of the present invention, the control unit includes a second switch provided between the first capacitor and the second capacitor, and the first capacitor is charged. The second switch is turned off, and the second switch is turned on when the first capacitor is discharged to charge the second capacitor.

  In the charge / discharge system of the present invention, the first battery is a capacitor.

  With this configuration, if the second capacitor is a capacitive element, charging and discharging without restriction are performed between the first capacitor and the second capacitor, so that the second capacitor can be rapidly charged.

  In the charge / discharge system according to the present invention, the first capacitor includes a plurality of capacitive elements connected in series.

  In the charge / discharge system of the present invention, the first battery is a secondary battery.

  According to the present invention, the second battery that supplies power to the load by discharging can be rapidly charged by discharging the first battery charged by the power source.

  Hereinafter, the charging / discharging system of embodiment of this invention is demonstrated using drawing. FIG. 1 is a diagram illustrating a configuration of an image forming apparatus to which a charge / discharge system is applied. An image forming apparatus 100 shown in FIG. 1 is a copying machine, a printer apparatus, or the like that employs an electrophotographic method, forms a toner image on a recording medium, and fixes the formed toner image on the recording medium with heat and pressure. . The image forming apparatus 100 includes an AC power supply 10, a triac 20, a triac control circuit 30, a charge / discharge system 50, a fuser circuit 60, and a mechatronic circuit 70.

  The AC power source 10 is a commercial power source, for example, and is a power source that supplies AC power. The triac 20 is a switch that supplies and shuts off power to the fuser circuit 60. The triac 20 is controlled to be turned on and off by the triac control circuit 30 based on, for example, the surface temperature of a fuser drum (not shown) in the fuser circuit 60.

  The charging / discharging system 50 converts AC power from the AC power supply 10 into DC and charges it, and supplies power to the mechatronic circuit 70 by discharging.

  FIG. 2 is a diagram illustrating a first configuration of the charge / discharge system and a configuration of the mechatronic circuit. The charge / discharge system 50 shown in FIG. 2 is detachable from the mechatronic circuit 70, and includes a charging power source 51, switches SW1, SW2, a precharging capacitor C1 such as an electric double layer capacitor, and a control unit 55. The On the other hand, the mechatronic circuit 70 includes a switch SW3, a capacitor C3, and a load 72.

  The charging power source 51 in the charging / discharging system 50 inputs AC power from the AC power source 10, converts it into DC power, and outputs it. The switch SW1 conducts and shuts off between the charging power source 51 and the precharging capacitor C1 under the control of the control unit 55. When the switch SW1 is on, the circuit constituted by the charging power source 51, the switch SW1 and the precharging capacitor C1 becomes conductive, and the precharging capacitor C1 is charged. On the other hand, when the switch SW1 is off, the circuit constituted by the charging power supply 51, the switch SW1 and the precharging capacitor C1 is cut off, so that the precharging capacitor C1 is not charged.

  The switch SW2 conducts and shuts off between the precharging capacitor C1 and the capacitor C3 in the mechatronic circuit 70 under the control of the control unit 55. When the switch SW1 is off and the switch SW2 is on, the circuit constituted by the precharging capacitor C1, the switch SW2, and the capacitor C3 is conducted, the precharging capacitor C1 is discharged, and the capacitor C3 is charged. On the other hand, when the switch SW2 is off, the circuit constituted by the precharge capacitor C1, the switch SW2, and the capacitor C3 is cut off, so that the precharge capacitor C1 is not discharged and the capacitor C3 is not charged.

  The control unit 55 has a function of detecting the state of charge of the precharging capacitor C1. When the precharge capacitor C1 is not fully charged, the control unit 55 turns on the switch SW1 and turns off the switch SW2 to charge the precharge capacitor C1. On the other hand, when the precharge capacitor C1 is fully charged, the control unit 55 turns off the switch SW1 and turns on the switch SW2, discharges the precharge capacitor C1, and charges the capacitor C3 in the mechatronic circuit 70. Let

  Further, the control unit 55 has a timer function, and in a time zone set by the timer (for example, night time zone), the switch SW1 is turned on and the switch SW2 is turned off to charge the precharging capacitor C1. . On the other hand, in the time zone other than the time zone set by the timer, the control unit 55 turns off the switch SW1 and turns on the switch SW2 to discharge the precharge capacitor C1, and the capacitor C3 in the mechatronic circuit 70 To charge.

  Further, after the operation of the image forming apparatus 100 is completed, the control unit 55 turns on the switch SW1 and turns off the switch SW2 to charge the precharge capacitor C1. On the other hand, the control unit 55 turns off the switch SW1 and turns on the switch SW2 before discharging the operation of the image forming apparatus 100 (for example, at the time of warming up) or simultaneously with the restarting of the operation, thereby discharging the precharging capacitor C1. The capacitor C3 in the circuit 70 is charged.

  The switch SW3 in the mechatronic circuit 70 conducts and shuts off between the capacitor C3 and the load 72. Specifically, the switch SW3 is turned on when the image forming apparatus 100 is in operation. As a result, a circuit constituted by the capacitor C3, the switch SW3, and the load 72 becomes conductive, the capacitor SW3 is discharged, and power is supplied to the load 72. On the other hand, the switch SW3 is turned off when the image forming apparatus 100 is not in operation. As a result, the circuit constituted by the capacitor C3, the switch SW3, and the load 72 is cut off, so that the capacitor SW3 is not discharged and power is not supplied to the load 72.

  FIG. 3 is a time chart showing a correspondence relationship between the switching operation of the switches SW1 to SW3 and the voltages of the precharging capacitor C1 and the capacitor C3. In the following description, it is assumed that a switching operation is performed according to the operating state of the image forming apparatus 100.

  When the image forming apparatus 100 finishes operating, the control unit 55 turns on the switch SW1 and turns off the switch SW2. As a result, the precharging capacitor C1 is charged and the voltage rises. However, since the charging power source 51 is small, a certain amount of time is required until the battery is fully charged. Thereafter, the control unit 55 turns off the switch SW1 and turns on the switch SW2 before or simultaneously with the resumption of the operation of the image forming apparatus 100. As a result, the precharge capacitor C1 is discharged, and the voltage drops. On the other hand, the capacitor C2 is charged by discharging the precharging capacitor C1. The capacitor C3 is rapidly charged because there is no restriction in charging / discharging between the capacitors due to the characteristics of the capacitor.

  Thereafter, the control unit 55 turns off the switch SW2 before the image forming apparatus 100 resumes operation or simultaneously with the resumption of operation. On the other hand, the switch SW3 in the mechatronic circuit 70 is turned on when the operation of the image forming apparatus 100 is resumed, the capacitor C2 is discharged, and power is supplied to the load.

  FIG. 4 is a diagram illustrating a second configuration of the charge / discharge system and a configuration of the mechatronic circuit. Compared with the charge / discharge system 50 shown in FIG. 2, the charge / discharge system 50 shown in FIG. 4 is newly provided with a precharge capacitor C2, and is connected in series with the precharge capacitor C1. The charging power supply 51 has a configuration in which a power supply device 80 and a power supply device 90 are connected in series. The switch SW1 includes a switch circuit SW11 connected to one end of the charging power source 51 (the side where the power source device 90 is not connected) and the other end of the charging power source 51 (the power source device of the power source device 90). The switch circuit SW12 is connected to the side 80).

  The power supply device 80 includes a transformer 81, a transistor 82 diode 83, and a capacitor 84. The transistor 82 is connected to the primary side (input side) of the transformer 81. On the other hand, the diode 83 is connected to the secondary side (output side) of the transformer 81, and the capacitor 84 is connected in parallel via the diode 83 on the secondary side of the transformer 81. Similarly, the power supply device 90 includes a transformer 91, a transistor 92 diode 93, and a capacitor 94. The transistor 92 is connected to the primary side (input side) of the transformer 91. On the other hand, the diode 93 is connected to the secondary side (output side) of the transformer 91, and the capacitor 94 is connected in parallel via the diode 93 on the secondary side of the transformer 91.

  The precharging capacitors C1 and C2 are connected to the capacitors 84 and 94 through the switch SW1, and are connected to the capacitor C3 in the mechatronic circuit 70 through the switch SW2. These precharging capacitors C1 and C2 are charged by discharging the capacitors 84 and 94 when the switch SW1 is on. When detecting that the precharge capacitors C1 and C2 are fully charged, the control unit 55 turns off the switch SW1 and the switch SW2. Next, the control unit 55 turns on the switch SW2. As a result, the precharging capacitors C1 and C2 are discharged, and the capacitor C3 in the mechatronic circuit 70 is charged. If the total capacitance of the precharge capacitors C1 and C2 connected in series is half of the capacitance of the capacitor C3, half of the total voltage of the precharge capacitors C1 and C2 becomes the voltage of the capacitor C3. In addition, the energy of the precharging capacitors C1 and C2 and the capacitor C3 is in an equilibrium state. In this state, the switch SW2 is turned off by the control unit 55, while the switch SW3 in the mechatronic circuit 70 is turned on, whereby electric power is supplied from the capacitor C3 to the load.

  According to this method, since there is no restriction on charging / discharging between capacitors, the precharging capacitors C1 and C2 are discharged and the capacitor C3 is charged almost instantly, and energy is transmitted. The time until the energy reaches an equilibrium state is determined by the capacitances of the precharging capacitors C1 and C2 and the capacitor C3 and the internal resistance.

  FIG. 5 is a diagram showing a third configuration of the charge / discharge system and a configuration of the mechatronic circuit. Compared with the charge / discharge system 50 shown in FIG. 2, the charge / discharge system 50 shown in FIG. 5 is newly provided with a precharge capacitor C2, and is connected in series with the precharge capacitor C1. Further, the charging power supply 51 is configured by only one power supply device including a transformer 81, a transistor 82 diode 83, and a capacitor 84, as compared with the charging power supply 51 shown in FIG. This power supply apparatus is a normal constant current / constant voltage control type power supply apparatus.

  The precharging capacitors C1 and C2 are connected to the capacitor 84 through the switch SW1, and are connected to the capacitor C3 in the mechatronic circuit 70 through the switch SW2.

These precharging capacitors C1 and C2 are charged by discharging the capacitor 84 when the switch SW1 is on. For example, the voltage applied to the entire precharge capacitors C1 and C2 is twice (2V) the voltage (V) applied to the capacitor C3 in the mechatronic circuit 70, and the capacitance of the precharge capacitor C1 is When the capacitance of C ₁ and the precharging capacitor C1 is C ₂ and C ₁ = C ₂ , the charge Q accumulated in the entire precharging capacitors C1 and C2 is stored in the precharging capacitors C1 and C2. If the total capacity and _{C 0,}

となる。このプレチャージ用キャパシタＣ１及びＣ２の全体に蓄積される電荷Ｑ、印加電圧２Ｖと、キャパシタＣ３が必要とする電荷量Ｑ、印加電圧Ｖとの関係からキャパシタＣ３の容量Ｃ_３をＣ_３＝Ｃ_０＝１／２Ｃ_１＝１／２Ｃ_２とすることによって、プレチャージ用キャパシタＣ１及びＣ２の全体の印加電圧とキャパシタＣ３の印加電圧はそれぞれＶとなる。また、

It becomes. Charge Q accumulated in the whole of the pre-charge capacitor C1, and C2, the applied voltage 2V, charge amount Q capacitor C3 requires the capacity C ₃ of the capacitor C3 from the relationship between the applied voltage V C _{3 =} C _By setting ₀ = ½C ₁ = ½C ₂ , the entire applied voltage of the precharging capacitors C1 and C2 and the applied voltage of the capacitor C3 become V, respectively. Also,

となる。

It becomes.

  As an example, it is assumed that the capacities of the precharging capacitors C1 and C2 are each 20 (F), and the voltage applied to each is 10 (V). In this case, the amount of charge accumulated in the entire precharging capacitors C1 and C2 is

となる。プレチャージ用キャパシタＣ１及びＣ２には、それぞれ１００（Ｃ）ずつの電荷が蓄積されている。次に、これらプレチャージ用キャパシタＣ１及びＣ２からスイッチＳＷ２を介して容量が１０（Ｆ）のキャパシタＣ３にエネルギーを移動させると、プレチャージ用キャパシタＣ１及びＣ２には、１００（Ｃ）ずつの電荷が蓄積される。一方、キャパシタＣ３に印加される電圧は１０（Ｖ）であり、電荷量は１００（Ｃ）となる。このキャパシタＣ３に蓄積されるエネルギーによってメカトロ系回路７０を瞬時に、すなわち、充電時間をほとんど必要とせずに駆動させることが可能となる。なお、この場合、プレチャージ用キャパシタＣ１及びＣ２の利用率は半減するものの、常にエネルギーを半分は蓄積した状態にあるので充電時間は半分で済む。また、プレチャージ用キャパシタＣ１及びＣ２の容量配分によって、出力電圧を可変したりエネルギー量を変更することもでき、負荷７２の消費電力に応じて適切に出力量を制御することが可能となる。

It becomes. Precharge capacitors C1 and C2 each store 100 (C) charges. Next, when energy is transferred from the precharging capacitors C1 and C2 to the capacitor C3 having a capacitance of 10 (F) via the switch SW2, the precharging capacitors C1 and C2 have 100 (C) charge. Is accumulated. On the other hand, the voltage applied to the capacitor C3 is 10 (V), and the charge amount is 100 (C). With the energy stored in the capacitor C3, the mechatronic circuit 70 can be driven instantaneously, that is, with almost no charging time required. In this case, although the utilization rate of the precharging capacitors C1 and C2 is halved, the charging time is only half because the energy is always stored in half. Further, the output voltage can be varied or the energy amount can be changed by the capacity distribution of the precharging capacitors C1 and C2, and the output amount can be appropriately controlled according to the power consumption of the load 72.

  As described above, the charging / discharging system 50 does not directly charge the capacitor C3 for supplying power to the load 72 in the mechatronic circuit 70 by the charging power source 51, but is charged by the charging power source 51. The capacitors C1 and C2 are provided, and the charged precharge capacitors C1 and C2 are discharged, so that the capacitor C3 can be rapidly charged. Therefore, even when the charging power supply 51 is downsized and the power supply capacity is small, when the load 72 in the mechatronic circuit 70 is driven, the charging power supply is discharged by discharging the charged precharging capacitors C1 and C2. The capacitor C3 in the mechatronic circuit 70 is rapidly charged without depending on the capacity of the 51, and further, the load 72 can be driven quickly.

  In addition, since power facilities such as a general commercial power supply have a limited power supply capacity (for example, 1.5 VKA), power is supplied to the load 72 in the mechatronic circuit 70 by the charge / discharge system 50. Therefore, much of the power such as a commercial power source can be used to drive the load in the fuser circuit 60.

  In the above-described embodiment, the charge / discharge system 50 is connected to the mechatronic circuit 70 to supply power. However, the charge / discharge system 50 may be connected to another circuit (for example, a logic circuit) to supply power. Good. In the above-described embodiment, the capacitor is used as the capacitor. However, a secondary battery such as a lead storage battery, a lithium ion battery, a nickel cadmium battery, or a manganese battery may be used instead of the capacitor. In the case of a battery, a single power source and V charging may be used.

  In the mechatronic circuit 70 in the above-described embodiment, a circuit for stabilizing the voltage applied to the load 72 may be provided. FIG. 6 is a diagram illustrating a configuration of a mechatronic circuit having a stabilization circuit. In FIG. 6, the stabilization circuit 73 is provided in parallel with the load 72 between the SW 3 and the load 72. Note that a booster circuit or a step-down circuit may be used as the stabilization circuit 73.

  As described above, the charge / discharge system according to the present invention can rapidly charge a capacitor that supplies power to a load without increasing the power supply capacity, and is useful as a charge / discharge system.

1 is a diagram illustrating a configuration of an image forming apparatus. It is a figure which shows the 1st structure of a charging / discharging system, and the structure of a mechatronics system circuit. It is a figure which shows the correspondence of switching operation | movement and the voltage of a capacitor. It is a figure which shows the 2nd structure of a charging / discharging system, and the structure of a mechatronics system circuit. It is a figure which shows the 3rd structure of a charging / discharging system, and the structure of a mechatronics system circuit. It is a figure which shows the structure of the mechatronics circuit which has a stabilization circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 AC power supply 20 Triac 30 Triac control circuit 50 Charging / discharging system 51 Charging power supply 55 Control part 60 Fuser circuit 70 Mechatronics circuit 72 Load 73 Stabilization circuit 100 Image forming device SW1, SW2, SW3 Switch SW11, SW12 Switch circuit C1, C2, precharge capacitor C3 capacitor

Claims (10)

A charge / discharge system for assisting power supply to a load in an image forming apparatus,
A first battery that selectively performs charging and discharging with power from a power source;
Control means for discharging the first battery and charging the second battery when a second battery that discharges the load is connected to the first battery. Charge and discharge system. The control means has detection means for detecting a charge state of the first capacitor, and charges the first capacitor when the detection means detects that the first capacitor is not fully charged. 2. The charge / discharge according to claim 1, wherein when it is detected that the first battery is fully charged, the first battery is discharged to charge the second battery. system. The control means has timer means for setting a time zone, and charges the first battery in a time zone set by the timer means, and a time zone other than the time zone set by the timer means. 3. The charging / discharging system according to claim 1, wherein the first battery is discharged to charge the second battery. 4. The control unit charges the first capacitor after the operation of the device incorporating the load, and discharges the first capacitor before or simultaneously with the resumption of operation of the device incorporating the load. The charge / discharge system according to any one of claims 1 to 3, wherein the second battery is charged. The control means includes a first switch provided between the power source and the first capacitor, turns on the first switch when the first capacitor is charged, and the first switch The charge / discharge system according to claim 2, wherein the first switch is turned on when the capacitor is discharged to charge the second capacitor. The first switch includes a first switch circuit connected to one end of the power source and a second switch circuit connected to the other end of the power source. Charge / discharge system. The control means has a second switch provided between the first capacitor and the second capacitor, turns off the second switch when charging the first capacitor, The charging / discharging system according to claim 5 or 6, wherein the second switch is turned on when the first capacitor is discharged to charge the second capacitor. The charge / discharge system according to claim 1, wherein the first battery is a capacitive element. The charge / discharge system according to claim 8, wherein the first battery includes a plurality of capacitive elements connected in series. The charge / discharge system according to claim 1, wherein the first battery is a secondary battery.

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