JP2004220915A - Heating device, fixing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating device, a fixing device, and an image forming device capable of charging an electric double-layer capacitor by a supply current corresponding to the turned-on or turned-off state of the load excluding a heating part, capable of coping with a sudden change of an input current, and surely preventing the input current from exceeding the maximum input current value of the whole device. <P>SOLUTION: The heating device comprises a heating part, a main power unit, an auxiliary power unit, a charging means, a switching means, and a control part. The heating part has a main heating element for producing heat by the charging current supplied from the main power unit and an auxiliary heating element for producing heat by the charging current supplied from the auxiliary power unit. The auxiliary power unit has an electric double-layer capacitor capable of charge and discharge of electricity. A charging means charges the capacitor of the auxiliary power unit by the charging current supplied from the main power unit. A switching means switches the supply of the charging current supplied to the auxiliary power unit from the main power unit and the supply of the current to the auxiliary heating element from the auxiliary power unit. The control part controls the charging current to the auxiliary heating element from the auxiliary power unit corresponding to the supplied current value to loads other than the heating part. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heating device, a fixing device, and an image forming apparatus, and more particularly, to a sub heater for shortening a start-up time of a fixing device included in an image forming device such as a printer and a copying machine, and a recovery time from an energy saving mode. It relates to the efficiency of power supply.
[0002]
[Prior art]
[Patent Document 1] Japanese Patent Application Laid-Open No. 10-282821 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-184554 In an image forming apparatus such as a copying machine, a printer, or a facsimile, a developed image is formed on an image forming material such as paper. In order to fix the toner, a fixing device is provided therein. The main part of this fixing device is composed of a fixing roller for heating the sheet to which the unfixed toner is adhered, and a pressure roller for pressing the sheet to pinch and convey it. Conventionally, such a fixing device is provided with a halogen heater or the like as a heater inside the fixing roller, and heats the inside of the fixing roller with the heater to raise the roller to a predetermined temperature. However, such a heating method using a heater requires a long time until the fixing roller is heated to a required temperature, and the loss of the heater itself is large. On the other hand, environmental issues such as global warming are currently being highlighted, and a fixing device with high efficiency and a short rise time is required.
[0003]
Therefore, several proposals have been made in the past. One of the proposals is to charge a secondary battery, which is an auxiliary power supply during standby of the apparatus, and to provide a secondary power supply when the apparatus is warmed up, in addition to the main power supply. 2. Description of the Related Art An image forming apparatus that supplies power from a secondary battery to reduce a rise time has been proposed. The fixing device disclosed in Patent Literature 1 charges a secondary battery as an auxiliary power supply during standby, and supplies power from the main power supply device and the secondary battery during startup. Further, in Patent Document 2 described above, while increasing the power-saving effect, the inrush current when supplying a large amount of power and the noise due to a sudden current change are reduced, the rise time is shortened, and the energization is performed to prevent the temperature from rising too much. A control method has been proposed. Specifically, Patent Document 2 uses a capacitor as an auxiliary power supply instead of a secondary battery. In detail, a main heating element and an auxiliary heating element are provided in the heating section, and power is supplied from the main power supply to the main heating element and from an auxiliary power supply having a capacitor to the auxiliary heating element to start heating the heating section. In this case, a large amount of electric power is supplied from the main power supply device and the auxiliary power supply device to raise the heating section to a predetermined temperature in a short time, and no electric power is supplied to the heating section during standby.
[0004]
[Problems to be solved by the invention]
However, according to Patent Literature 1, since a secondary battery is used as an auxiliary power supply, the secondary battery is generally a CADNICA battery or a lead storage battery, but these secondary batteries are charged and discharged. It is said that the repetition of the above causes a decrease in capacity, and the life is shorter as the battery is discharged with a larger current. Even in the case of CADNICA batteries, which are generally said to have a long life at a large current, the number of repetitions of charge / discharge is about 500 to 1000 times. If the battery is mounted on the image forming apparatus and charged and discharged 20 times a day, the battery life is reduced to about one month, and the replacement cost and the running cost such as the battery cost become extremely expensive. In the case of a lead storage battery, sulfuric acid is used, which is not preferable for office equipment. In addition, secondary batteries cannot be rapidly charged, and several tens of minutes are required for a full charge even if it is said to be fast. Further, Patent Document 2 does not refer to the timing and amount of charge of the capacitor of the auxiliary power supply circuit. Therefore, the configuration of Patent Document 2 is not shown in FIG. As shown in FIG. 6, which shows the relationship between the operation of the conventional example and the supply current value to the sub-heater because of the feedback type control, the constant current to the electric double layer capacitor is enlarged as shown in FIG. If the input current suddenly increases during charging, the change cannot be followed, and the image forming apparatus is not used until the input current increases and the amount of constant current charged to the electric double layer capacitor decreases in accordance with the increase. However, there is a disadvantage that a current exceeding the maximum current may be supplied. Specifically, after the supply current value exceeds the threshold value, the drive / control section 103 recognizes that the threshold value has been exceeded via the input power calculation control means 111, and outputs a charge / discharge switching control signal to perform switching. An input current exceeding the threshold value flows for a period of time until the means 113 responds thereto, which is a problem from the viewpoint of energy saving.
[0005]
The present invention is intended to solve such a problem. The electric double capacitor can be charged with a supply current value according to an on / off state of a load other than a heating unit, and a rapid change in an input current can be achieved. It is another object of the present invention to provide a heating device, a fixing device, and an image forming apparatus, which can reliably prevent the maximum input current value of the entire apparatus from being exceeded.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a heating device according to the present invention includes a heating unit, a main power supply, an auxiliary power supply, a charging unit, a switching unit, and a control unit. The heating section has a main heating element that generates heat by a charging current supplied from the main power supply device, and an auxiliary heating element that generates heat by a charging current supplied from the auxiliary power supply device. The auxiliary power supply has a chargeable / dischargeable electric double capacitor. The charging means charges a capacitor of the auxiliary power supply with a charging current supplied from the main power supply. The switching means switches between supply of a charging current from the main power supply to the auxiliary power supply and supply of a current from the auxiliary power supply to the auxiliary heating element. The control unit adjusts a charging current value from the auxiliary power supply to the auxiliary heating element according to a supply current value to a load other than the heating unit.
[0007]
Further, the control unit calculates the sum of the supply current values of the loads to be turned off based on the correspondence between the charging current value and the load other than the heating unit set in advance, and assists with the current value of the calculation result. The constant current charging from the power supply to the auxiliary heating element is performed.
[0008]
Furthermore, the control unit calculates the sum of the supply current values of the loads that are turned on based on the correspondence relationship between the load and the load other than the heating unit, which is set in advance, and calculates the current value of the calculation result as A constant current charging from the auxiliary power supply to the auxiliary heating element is performed with a current value subtracted from the total input current value supplied to other loads and the heating unit and limited in advance.
[0009]
According to another aspect of the invention, a fixing device includes the above-described heating device, and includes a heating unit in a fixing roller.
[0010]
Further, an image forming apparatus according to another aspect of the present invention includes the above-described fixing device, and heats and fuses an electrophotographic toner image to a recording member.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The heating device of the present invention has a heating unit, a main power supply, an auxiliary power supply, a charging unit, a switching unit, and a control unit, and the heating unit is a main heating element that generates heat by electric power supplied from the main power supply, An auxiliary heating element that generates heat by electric power supplied from the auxiliary power supply, the auxiliary power supply has a chargeable / dischargeable electric double capacitor, and the charging means uses the electric power supplied from the main power supply to supply the auxiliary power supply. The switching means switches between charging of the auxiliary power supply and power supply to the auxiliary heating element from the auxiliary power supply, and the control unit controls the auxiliary power supply according to the amount of power supplied to other loads other than the heating unit. Adjust the power supply from the device to the auxiliary heating element.
[0012]
【Example】
FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. In FIG. 1, an image forming apparatus 100 according to the present exemplary embodiment includes a fixing unit 101 having a main heater 101-1, a sub-heater 101-2, and a temperature sensor 101-3, a power supply unit 102 connected to a commercial power supply 200, an input power calculation. Control / drive unit 103 having means 103-1; scanner motor 104; main motor 105; developing motor 106; paper feed clutch 107; branch solenoid 108; cooling fan 109; rectifying / charging means 112; switching means 113; It comprises a capacitor 114 and a voltage detection means 115. Here, the switching unit 113 controls the charging of the electric double-layer capacitor 114 from the commercial power supply 200 and the discharging to the sub-heater 102-2 by switching control by a charge / discharge switching control signal from the control / drive unit 103. Further, ON / OFF of the main heater 101-1 is controlled by a control signal from the control / drive unit 103 according to a mode of the image forming apparatus 100, such as a warm-up mode, a copy mode, a standby mode, and an energy saving mode. I have. Further, the input power calculation means 103-1 provided in the control / drive unit 103 includes a voltage detection value from the voltage detection means 115 for detecting the voltage of the electric double layer capacitor 114, and scanner motor 104, Based on control signals to the main motor 105, the developing motor 106, the paper feed clutch 107, the branch solenoid 108, and the cooling fan 109, the charge amount control signal is rectified to the rectifying / charging means 112, and the charge / discharge switching control signal is switched to the switching means 113. Output to In this embodiment, for example, as shown in FIG. 2, the charging current value of the electric double layer capacitor 114 is set in advance for each load. This response is determined based on how much the total input current value from the commercial power supply 2 increases when each load is turned on. For example, when a commercial power source with an upper limit of 15 A is input, if the current consumption excluding the loads listed in FIG. 2 is a maximum of 5 A, all the loads listed in FIG. 2 are turned on, and the charging current value of the electric double layer capacitor 114 is reduced. If it is 0 A, the total input current value input from the commercial power supply 200 to the image forming apparatus 100 is limited to a maximum of 15 A. Conversely, when all the loads listed in FIG. 2 are off, the total input current value is limited to a maximum of 15 A if the electric double layer capacitor 114 is charged at a constant current of 10 A or less. That is, the sum of the charging current values of the off-loads among the loads listed in FIG. 2 is the maximum current value at which the electric double-layer capacitor 114 can be charged at a constant current.
[0013]
Next, the operation of the image forming apparatus according to the present embodiment will be described. The input power calculation means 103-1 of the control / drive unit 103 shown in FIG. The sum of the charging current values of the off-loads among the loads to be performed is calculated. A charge amount control signal is output to the rectifying / charging means 112 so as to charge the electric double layer capacitor 114 with the current value of the operation result. Conversely, when turning off the load, the load is turned off first, and then the charge amount control signal is output. By performing such control, the charge control to the electric double layer capacitor in which the input current may exceed 15 A in the prior art as shown in FIG. 6 is improved, and as shown in FIG. The value can be limited to 15A or less.
[0014]
Further, since the correspondence between each load and the charging current value of the electric double layer capacitor is set based on the AC input current as in the image forming apparatus of the present embodiment, the AC input current can be reliably limited. However, similarly, if the correspondence between each load and the charging current value of the electric double layer capacitor is set based on the AC input power, the AC input power can be reliably limited.
[0015]
It should be noted that the present invention is not limited to the above embodiment, and it goes without saying that various modifications and substitutions can be made within the scope of the claims.
[0016]
【The invention's effect】
As described above, the heating device of the present invention includes the heating unit, the main power supply, the auxiliary power supply, the charging unit, the switching unit, and the control unit. The heating section has a main heating element that generates heat by a charging current supplied from the main power supply device, and an auxiliary heating element that generates heat by a charging current supplied from the auxiliary power supply device. The auxiliary power supply has a chargeable / dischargeable electric double capacitor. The charging means charges a capacitor of the auxiliary power supply with a charging current supplied from the main power supply. The switching means switches between supply of a charging current from the main power supply to the auxiliary power supply and supply of a current from the auxiliary power supply to the auxiliary heating element. The control unit adjusts a charging current value from the auxiliary power supply to the auxiliary heating element according to a supply current value to a load other than the heating unit. Therefore, the electric double-layer capacitor can be charged with the amount of power supply according to the on / off state of the load, so that it is possible to cope with a rapid change in the input current and to reliably prevent the maximum power supply amount of the entire device from being exceeded. be able to.
[0017]
Further, the control unit calculates the sum of the supply current values of the loads that are turned off based on the preset correspondence between the load other than the heating unit and the charging current value, and calculates the sum of the current values of the calculation results. The auxiliary power supply performs constant-current charging of the auxiliary heating element. Therefore, the input current from the commercial power supply to the heating device can be reliably suppressed to be equal to or less than the target value of the device.
[0018]
Furthermore, the control unit calculates the sum of the supply current values of the loads that are turned on based on the correspondence relationship between the load and the load other than the heating unit, which is set in advance, and calculates the current value of the calculation result as A constant current charging from the auxiliary power supply to the auxiliary heating element is performed with a current value subtracted from the total input current value supplied to other loads and the heating unit and limited in advance. Therefore, the input current from the commercial power supply to the heating device can be reliably suppressed to be equal to or less than the target value of the device.
[0019]
According to another aspect of the invention, a fixing device includes the above-described heating device, and includes a heating unit in a fixing roller. Therefore, it is possible to reliably prevent the maximum power supply amount of the entire apparatus from being exceeded.
[0020]
Further, an image forming apparatus according to another aspect of the present invention includes the above-described fixing device, and heats and fuses an electrophotographic toner image to a recording member. Therefore, the toner can be stably heated and melted, and a high quality toner image can be fixed to the recording member and formed.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a relationship between charging current values of an electric double layer capacitor corresponding to each load.
FIG. 3 is a diagram illustrating a relationship between an operation of the image forming apparatus of the present embodiment and a current value supplied to a fixing device.
FIG. 4 is a block diagram illustrating a configuration of a conventional image forming apparatus.
FIG. 5 is a diagram illustrating a relationship between an operation of a conventional image forming apparatus and a current value supplied to a fixing device.
FIG. 6 is an enlarged view of a portion surrounded by a dotted line in FIG. 5;
[Explanation of symbols]
100: image forming apparatus, 101: fixing unit, 101-1: main heater,
101-2; sub heater, 101-3; temperature sensor, 102; power supply unit,
103: control / drive unit, 103-1: input power calculation means,
104; scanner motor, 105; main motor,
106; developing motor; 107; paper feed clutch; 108; branch solenoid;
109: cooling fan, 110: input voltage / current detecting means,
111: input power calculation control means, 112; rectification / charge means,
113; switching means, 114; electric double layer capacitor, 115; voltage detecting means,
200; commercial power supply.

Claims (5)

It has a heating unit, a main power supply, an auxiliary power supply, a charging unit, a switching unit, and a control unit. The heating unit is supplied with a main heating element that generates heat by a charging current supplied from the main power supply, and is supplied from the auxiliary power supply. An auxiliary heating element that generates heat by a charging current, the auxiliary power supply device has a chargeable / dischargeable electric double-layer capacitor, and the charging means uses an electric double-layer capacitor of the auxiliary power supply device with a charging current supplied from the main power supply device. The capacitor is charged, the switching means switches between supplying the charging current from the main power supply to the auxiliary power supply and supplying the current to the auxiliary heating element from the auxiliary power supply, and the control unit controls the load other than the heating unit. A heating device that adjusts a charging current value from the auxiliary power supply device to the auxiliary heating element according to a current value supplied to the heating device. The control unit calculates the sum of the supply current values of the loads to be turned off based on a preset relationship between the load other than the heating unit and the charging current value, and calculates the auxiliary power using the calculated current value. The heating device according to claim 1, wherein constant current charging is performed from the device to the auxiliary heating element. The control unit calculates the sum of the supply current values of the loads that are turned on based on the correspondence between the charging current value and a load other than the heating unit set in advance, and calculates the current value of the calculation result as another value. 2. The heating device according to claim 1, wherein the auxiliary power supply device performs constant current charging from the auxiliary power supply to the auxiliary heating element with a current value subtracted from a total input current value supplied to the load and the heating unit and limited in advance. A fixing device comprising the heating device according to claim 1, wherein the fixing roller has a built-in heating unit. An image forming apparatus comprising the fixing device according to claim 4, wherein an electrophotographic toner image is heated and welded to a recording member.

Images