JP2008098182A - Induction heating device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in which a large number of heat-generation members are put in a fixing roller, thereby making it difficult to thin the fixing roller and to lower its thermal capacity. <P>SOLUTION: In this heating device, heat-generation means 6 generates heat by electric powers supplied from a main electric source device 4 and an auxiliary electric source device 5. The device is provided with: electric power adjustment means 7 to adjust the electric power supplied by the auxiliary electric source device 5; and a control device to control the electric power adjustment means 7 according to information from the outside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heating device that heats various materials and various devices, a fixing device, and an image forming apparatus such as a copying machine, a printer, and a facsimile.

An image forming apparatus such as a copying machine, a printer, or a facsimile has a process of forming an image on a recording medium such as plain paper or OHP paper, and various image recording methods for performing this process are realized. Among these image recording methods, the electrophotographic method is widely adopted in image forming apparatuses because of high speed, image quality, cost, and the like.
In the electrophotographic system, there is a fixing process in which an unfixed toner image is formed on a recording medium such as plain paper or OHP paper, and this unfixed toner image is fixed to the recording medium with heat and pressure. As a fixing device for performing this fixing process, the heat roller method is currently most frequently used from the viewpoint of high speed and safety.

  In the heat roller system, a fixing roller heated by a heat generating member such as a halogen heater and a pressure roller disposed opposite to the fixing roller are pressed to form a mutual pressure contact portion called a nip portion, and fixing. In this method, a recording medium is passed between a roller and a pressure roller, and the recording medium is heated and pressed to fix an unfixed toner image on the recording medium.

The fixing roller mainly uses a metal roller such as iron or aluminum and has a large heat capacity. For this reason, the fixing roller has a drawback that it requires a long start-up time of several minutes to several tens of minutes to raise the temperature to about 180 ° C., which is a usable temperature.
Therefore, in the image forming apparatus, even when the user is not performing image formation, power is supplied to the heat generating member for heating the fixing roller, and the temperature of the fixing roller is kept at a preheating temperature slightly lower than the usable temperature. Yes. As a result, the fixing roller immediately rises to the usable temperature from the standby state, and the user does not wait for the temperature of the fixing roller to rise.

However, even during standby when the image forming apparatus is not used, it is not necessary for image formation directly, so to speak, extra power is consumed during standby. There is also a survey result that the standby energy consumption is about 70 to 80% of the energy consumption of the image forming apparatus.
In recent years, energy conservation regulations have been enacted in each country due to increased awareness of environmental protection. In Japan, the Energy Conservation Law has been revised and strengthened, and energy conservation programs such as Energy Star and Zero Energy Star Mode (ZESM) have been established in the United States.

When trying to save power in order to comply with these regulations and programs, reducing the standby energy consumption has a great energy saving effect. For this reason, it is desirable that the standby power supply when the image forming apparatus is not used be zero.
However, if the image forming apparatus has the configuration of the conventional fixing device and the standby power is set to zero, it takes several minutes for the fixing roller to warm up at the time of re-startup, and the waiting time is long and user-friendly. Will get worse. For this reason, a configuration of a fixing device that quickly raises the temperature of the fixing roller is required to realize an energy-saving image forming apparatus. For example, in the above-described ZESM, 10 seconds or less is required for restarting.

  In order to shorten the heating time of the fixing roller, it is preferable to increase the input energy per unit time to the heat generating member for heating the fixing roller, that is, the rated power. In fact, some high-speed machines with a high image forming speed (image forming apparatuses with a high image forming speed) support a power supply voltage of 200V. However, in general offices in Japan, the power supply is generally 100V15A and the upper limit is 1500W, and in order to make the image forming apparatus compatible with the 200V power supply, a special work related to the power supply at the place where the image forming apparatus is installed is performed. There is a need and this is not a general solution.

  Also, an image forming apparatus product that increases the total input power by using two systems of commercial power of 100V15A has been put into practical use, but the image forming apparatus cannot be installed unless the outlets of the two systems are nearby. For this reason, until now, even if it was attempted to raise the temperature of the fixing roller in a short time, the upper limit of the energy input to the fixing device could not be increased.

In order to realize energy saving of the image forming apparatus by increasing the maximum power supply to the fixing apparatus, a configuration of a fixing apparatus using an auxiliary power supply apparatus has been proposed. Typical examples of the rechargeable auxiliary power supply device include a lead storage battery and a CADNICA battery.
However, the secondary battery has a property that it deteriorates when it is repeatedly charged and discharged, the capacity decreases, and the life is shortened as the battery is discharged with a large current. Even for CADNICA batteries, which are generally considered to have a long current with a large current, the number of charge / discharge cycles is about 500 to 1000 times, and if the battery is charged / discharged 20 times a day, the battery life will be about one month. Will come. This takes time to replace the battery, and the running cost such as battery cost is very high. Furthermore, since it takes several hours to fully charge a battery having a large capacity, it cannot be used for applications in which charging and discharging are repeated many times a day, and it has been difficult to realize in practice.

Since a practical auxiliary power supply device cannot be realized with the secondary battery, Patent Document 1 proposes a technique using a large-capacity capacitor (capacitor) such as an electric double layer capacitor as the auxiliary power supply device. A large-capacity capacitor has the following advantageous characteristics.
1) The number of repetitions of charge / discharge is almost unlimited at tens of thousands or more, charging characteristics are hardly deteriorated, and regular maintenance is unnecessary.
2) The charging time can be set to several seconds to several tens of seconds while the battery, which is a secondary battery, takes several hours.
In addition, since the electric double layer capacitor can flow a large current of several tens to several hundreds of amperes, power can be supplied in a short time.

  As described above, when a large-capacity capacitor is used as the auxiliary power supply device, power exceeding the power limit of the commercial power supply can be supplied to the fixing device in a short time from several seconds to several tens of seconds when the fixing device starts up. For this reason, it is possible to realize a fixing device having a short start-up time with high reliability and durability.

  Patent Document 2 describes a technique for supplying stable power for a long time by stepping down a capacitor voltage by a switching circuit when supplying power from a large-capacity capacitor. This technology is configured to supply power from an auxiliary power supply device when an image forming apparatus such as a copying machine is started up.

  FIG. 5 shows each example of a fixing device using electric power from the auxiliary power supply device. The fixing device shown in FIG. 5A includes a main heat generating member 6a that generates heat when power is supplied from a main power supply device, an auxiliary heat generating member 6b that generates heat when passing paper, and an auxiliary heat generating member 6c that generates heat when starting up. The heating member 6 is provided in the heating member 21, and power is supplied to the auxiliary heating members 6b and 6c from the auxiliary power supply device. When this fixing device is used, a large amount of power exceeding the power supplied by the main power supply device 4 is supplied to the heat generating member 6 by supplying power from both the main power supply device 4 and the auxiliary power supply device 5 to the heat generating member 6 simultaneously. it can.

  For this reason, as shown in FIG. 6, the temperature rise time of the heating member 21 is higher when the main power supply device and the auxiliary power supply device are used simultaneously than when only the main power supply device is used. Can be shortened. In order to promote energy saving, heating the heating member 21 for a short time is a very important issue, and heating the heating member 21 for a short time is performed by supplying power to the heating member 6 that exceeds the rated power of the commercial power supply. The fixing device shown in FIG. 5A is very useful.

  The fixing device shown in FIG. 5 (b) is the same as the fixing device shown in FIG. 5 (a), but instead of the main heat generating member 6a, the heated member 21 is covered when a small heated object passes through continuously. The main heating member 6a-1 having a different heating range provided corresponding to the center and the end of the heating member 21 in order to cope with the problem of the temperature rise in the non-sheet passing portion where the heating body non-passage area becomes an abnormally high temperature. , 6a-b, and a total of four heating members 6a-1, 6a-b, 6b, 6c are placed in the fixing roller as the heating member 21.

JP 2000-315567 A JP 2003-140484 A

  By mounting the fixing device using the auxiliary power device, the image forming apparatus can realize an energy saving and extremely short start-up time. Further, in order to promote the temperature rise of the fixing device for a short time, there are a method of increasing the input power to the fixing device and a method of decreasing the heat capacity of the fixing device. For this reason, the use of a thin fixing roller having a small heat capacity in the above-described prior art makes it possible to raise the temperature in a shorter time.

  In the case of a high-speed machine that exceeds 60 sheets per minute, the surface temperature of the thin fixing roller with a small heat capacity is just after startup because the heat amount of the fixing roller is taken away by a recording medium such as plain paper. Due to the continuous feeding of paper, it quickly dropped below the required fixing temperature, and there was a problem that a high-speed machine could not use a thin fixing roller. By introducing the temperature when the temperature drops, the problem can be solved, and the start-up time can be greatly reduced and energy can be saved in a high-speed machine.

However, in developing an image forming apparatus using a large-capacity capacitor and a thin fixing roller, the following problems have been clarified in improving the performance.
In a fixing device for supplying power from an auxiliary power supply, a method in which a heating member for the auxiliary power supply is provided in a fixing roller is generally used. Therefore, in an image forming apparatus in which power from the auxiliary power supply device is input to the fixing device at the time of startup and paper passing, the heating members having different resistances for startup and paper passing due to the difference in the amount of power required The input power is adjusted by having

When these heat generating members are combined with heat generating members for the main power supply device in the fixing roller, a total of three heat generating members are put in the fixing roller. Further, in a high-speed image forming apparatus that requires an auxiliary power supply device, when a recording medium with a small size passes through the fixing device continuously, the non-passing region where the recording medium non-passing area of the fixing roller becomes an abnormally high temperature. In order to cope with the problem of the temperature rise of the paper section, it is common to provide two heat generating members having different heat generation ranges corresponding to the center portion and the end portion of the fixing roller, and a total of four heating members are provided in the fixing roller. There is also a case where a heating member is inserted.
It is difficult to put four heat generating members in the fixing roller with a small-diameter fixing roller in terms of space, and a synergistic effect between thinning the fixing roller and reducing the diameter effective for reducing heat capacity cannot be exhibited.

An object of the present invention is to provide a heating device and a fixing device capable of supplying appropriate power from the auxiliary power supply device to the heat generating member according to the use without increasing the number of heat generating members for the auxiliary power supply device. Objective.
Another object of the present invention is to provide a heating device and a fixing device that can be started up in a short period of time and can supply appropriate power to the heat generating member from an auxiliary power supply device according to the application.

Another object of the present invention is to provide a heating device and a fixing device capable of adjusting the voltage of the power supplied to the auxiliary power supply device according to the application.
Another object of the present invention is to provide a heating device and a fixing device capable of downsizing a switching element of an electric circuit for supplying electric power from an auxiliary power supply device to a heat generating member.

Another object of the present invention is to provide a heating device and a fixing device with high heating efficiency.
Another object of the present invention is to provide a heating device and a fixing device capable of supplying power of an appropriate auxiliary power supply device according to the operating state of the image forming apparatus.
Another object of the present invention is to provide a heating device and a fixing device that can start up for a short time and supply power to an appropriate auxiliary power supply device when passing through an object to be heated.

Another object of the present invention is to provide a heating device and a fixing device that can supply power of an appropriate auxiliary power supply device in accordance with the type of the object to be heated.
Another object of the present invention is to provide a heating device and a fixing device capable of shortening the charging time of the auxiliary power supply device and extending the life of the auxiliary power supply device.
Another object of the present invention is to provide a heating device and a fixing device that do not require charging from a main power supply device and can be started up for a short time.

Another object of the present invention is to provide a heating device and a fixing device that have a short start-up time and are low in cost and small in size.
Another object of the present invention is to provide an image forming apparatus capable of reducing the diameter of a fixing member and further saving energy due to a reduction in heat capacity.

  In order to achieve the above object, the invention according to claim 1 is a heating device that generates heat from the power source supplied from the main power source device or the auxiliary power source device, and a power adjusting unit that adjusts the power supplied to the auxiliary power source device. And a control device that controls the power adjusting means in accordance with external information.

  According to a second aspect of the present invention, in the heating device according to the first aspect, the heating unit includes a resistance heating element, the power adjustment unit includes a transformer, and the control unit controls the power adjustment unit. The power supplied to the auxiliary power supply device is adjusted.

  The invention according to claim 3 is the heating apparatus according to claim 2, wherein the transformer is a DC / DC converter.

  The invention according to claim 4 is the heating apparatus according to claim 1 or 2, further comprising a DC / AC converter that converts DC power into AC power and supplies the AC power to the heating means.

  The invention according to claim 5 is the heating apparatus according to claim 1, wherein the heating means is a magnetic induction heating means.

  According to a sixth aspect of the present invention, in the heating apparatus according to any one of the first to fifth aspects, the external information is information indicating an operating state of the image forming apparatus.

  According to a seventh aspect of the present invention, in the heating device according to the sixth aspect, the supply power of the auxiliary power supply device during warm-up is greater than the supply power of the auxiliary power supply device when the heating unit heats the object to be heated. It ’s a big one.

  The invention according to claim 8 is the heating device according to any one of claims 1 to 7, wherein a high power mode for supplying power supplied from the auxiliary power device with a first predetermined power, and the auxiliary power source The apparatus has a low power mode in which the power supplied from the apparatus is supplied by a second predetermined power smaller than the first predetermined power, and the control apparatus switches the mode according to the external information.

  According to a ninth aspect of the present invention, in the heating device according to any one of the first to eighth aspects, the power supplied to the auxiliary power device is adjusted according to the type of the object to be heated.

  The invention according to claim 10 is the heating apparatus according to any one of claims 1 to 9, wherein the auxiliary power supply device is a capacitor.

  The invention according to claim 11 is the heating apparatus according to any one of claims 1 to 9, wherein the auxiliary power supply device is a fuel cell.

  According to a twelfth aspect of the present invention, there is provided a magnetic induction heating device that supplies power of the main power supply device capable of steady power supply and power of the auxiliary power supply device to the heat generating portion. The power generated by superimposing the power of the power supply device is supplied to the heat generating portion.

  The invention according to claim 13 includes the heating device according to any one of claims 1 to 11 or the heating device according to claim 12, and fixing means heated by the heating device.

  The invention according to claim 14 is provided with the fixing device according to claim 13.

ADVANTAGE OF THE INVENTION According to this invention, appropriate electric power can be supplied to a heat generating member from an auxiliary power supply device according to a use, without increasing the number of heat generating members for auxiliary power devices.
According to the present invention, it is possible to start up for a short time, and it is possible to supply appropriate power from the auxiliary power supply device to the heat generating member according to the application.

According to the present invention, the voltage of the power supplied from the auxiliary power supply device can be adjusted according to the application.
According to the present invention, the switching element of the electric circuit that supplies power from the auxiliary power supply device to the heat generating member can be reduced in size.

According to the present invention, the heating efficiency is increased.
According to the present invention, it is possible to supply appropriate power of the auxiliary power supply device according to the operating state of the image forming apparatus.
ADVANTAGE OF THE INVENTION According to this invention, the electric power supply of an appropriate auxiliary | assistant power supply device at the time of starting for a short time and a to-be-heated body passage can be performed.

ADVANTAGE OF THE INVENTION According to this invention, the electric power of a suitable auxiliary power supply apparatus can be supplied according to the kind of to-be-heated body.
According to the present invention, the charging time of the auxiliary power supply device can be shortened, and the life of the auxiliary power supply device can be extended.
According to the present invention, it is possible to start up for a short time without the need for charging from the main power supply device.

According to the present invention, the start-up time is short, and the size is reduced at low cost.
According to the present invention, it is possible to reduce the diameter of the fixing member, and it is possible to further save energy due to the reduction in heat capacity.

  FIG. 8 shows an image forming apparatus according to an embodiment of the present invention. This image forming apparatus is set to have a high overall height so that it can be used by being placed on the floor, and the whole is composed of an upper part and a lower part. The upper part has an automatic document feeder (not shown) provided above and an optical unit comprising optical elements (not shown) provided below, and each of the image forming systems located below the automatic unit. Has a unit. The lower part has a paper feed unit in which a plurality of paper feed trays 40 on which a plurality of sizes of recording media (recording members such as plain paper and HP paper) P are respectively placed are housed.

  In FIG. 8, reference numeral 41 denotes a drum-shaped photoconductor that is an example of an image carrier made of a rotating body. Around this photoconductor 41, in the order of rotation in the direction indicated by the arrow, a charging device 42 composed of a charging roller, a mirror 43 constituting a part of the exposure means, a developing means 44 having a developing roller 44a, and a recording member P A transfer device 48 for transferring the developed image on the photoconductor 41 to the transfer paper as a transfer device, a cleaning means 46 provided with a blade 46a in sliding contact with the peripheral surface of the photoconductor 41, and the like are arranged. The surface of the photoreceptor 41 is scanned with the exposure light Lb via the mirror 43 between the charging device 42 and the developing roller 44a. The irradiation position of the exposure light Lb is called an exposure unit 45.

  A transfer device 48 faces the lower surface of the photoconductor 41. A portion of the photoconductor 41 facing the transfer device 48 is a transfer unit 47. A pair of registration rollers 49 is provided at a position further upstream of the transfer unit 47 in the transfer paper conveyance direction. The recording member P stored in the selected paper feed tray among the plurality of paper feed trays 40 is fed by the paper feed roller 51, guided by the transport guide, and transported to the registration roller 49. A fixing device 20 is disposed further downstream of the transfer unit 47 in the transfer sheet conveyance direction.

  In this image forming apparatus, image formation is performed as follows. The photosensitive member 41 is rotated by a drive unit (not shown) and starts rotating. During the rotation, the photosensitive member 41 is uniformly charged by the charging device 42 in the dark, and the exposure unit 45 exposes the exposure light Lb by the exposure unit. And an electrostatic latent image corresponding to the image to be created is formed. The electrostatic latent image is moved to the developing device 44 by the rotation of the photoconductor 41, where it is visualized by toner to form a toner image.

  On the other hand, feeding of the transfer paper P as a recording member on the paper feed tray 40 is started by the paper feed roller 51, and temporarily stops at the position of the pair of registration rollers 49 via the conveyance path indicated by the broken line. The toner image and the transfer unit 47 wait for the delivery timing. When this timing arrives, the transfer paper P that has stopped at the registration roller 49 is sent out from the registration roller 49 and conveyed toward the transfer unit 47.

  The toner image on the photoconductor 41 and the transfer paper P coincide with each other at the transfer unit 47, and the toner image on the photoconductor 41 is transferred onto the transfer paper P by the electric field generated by the transfer device 48.

  In this way, the toner image formed in the image forming section as an image forming system comprising the photosensitive member 41 and the surrounding units 42, 44, 48, 46 and the exposure means is transferred, and the transfer paper P carrying this is transferred to the fixing device 20. It is sent out toward. The toner image on the transfer paper P is fixed on the transfer paper P while passing through the fixing device 20 and discharged to the paper discharge unit 52.

Further, the image forming apparatus forms images on both sides of the transfer paper P in the duplex mode. In the duplex mode, the transfer paper having the toner image formed on the surface as described above is conveyed to the automatic duplex device 39 by a branching claw (not shown), and the front and back sides are reversed by switchback inversion. Re-feed the roller 49.
On the other hand, the residual toner remaining on the photoconductor 41 without being transferred by the transfer unit 47 reaches the cleaning device 46 along with the rotation of the photoconductor 41, and is cleaned while passing through the cleaning device 46 for the next image formation. Prepare.
FIG. 1 shows a circuit configuration of the fixing device 20, and FIG. 2 shows a cross section of the fixing device 20. The main power supply device 4 is a power source to which power is supplied from a commercial power supply, and can be supplied with power by being connected to an outlet. The auxiliary power supply device 5 includes an electric double layer capacitor 5a and a charger that charges the electric double layer capacitor 5a with electric power from the main power supply device 4. The electric double layer capacitor has the following characteristics and is very excellent as the auxiliary power supply device 5 of the fixing device 20.
1) The number of repetitions of charging / discharging is tens of thousands or more and is almost unlimited, charging characteristics are hardly deteriorated, and regular maintenance is unnecessary.
2) The charging time can be set to several seconds to several tens of seconds while the battery, which is a secondary battery, takes several hours. Further, a large current of several tens to several hundreds of amperes can be passed, and power can be supplied in a short time.

  The heating member 21 as a heating means includes a heating member 6 including a main heating member 6a and an auxiliary heating member 6b. In this embodiment, the main heating member 6a and the auxiliary heating member 6b are halogen heaters. Further, a thin fixing roller is used for the heating member 21. The thin fixing roller 21 has an aluminum core metal having a thickness of 0.7 mm, a Teflon (registered trademark) layer having a thickness of 0.02 mm as a release layer outside the core metal, and has a diameter of 40 mm. Since the thin fixing roller 21 has a very small heat capacity, it can be heated for a short time.

  The pressure member 22 is a pressure member that is pressed against the thin fixing roller 21 and applies pressure to the heated body P. As the heated body P passes through the nip portion formed by the heating member 21 and the pressure member 22, the toner image is fixed by heating and pressure. The main heat generating member 6a is supplied with electric power from the main power supply device 4 to generate heat, and the auxiliary heat generating member 6b is supplied with electric power from the auxiliary power supply device 5 to generate heat.

  In this embodiment, the auxiliary power supply 5 accommodates an 80V capacitor module in which 32 capacitor cells of 500F and 2.5V are collected. When the power of the auxiliary power supply 5 is used when the fixing device 20 is passed, the voltage of the auxiliary power supply 5 is used as it is, and when it is used when the fixing device 20 is started up, the voltage of the auxiliary power supply 5 is used as the power. The voltage is boosted to 140 V from the DC / DC converter 7 as the adjusting means. The auxiliary power supply 5 boosts the voltage of the auxiliary power supply 5 to 140V during the transformation operation and supplies it to the auxiliary heating member 6b. During the operation without the transformation, the auxiliary power supply 5 remains at the voltage of 80V. And the voltage of the auxiliary power supply 5 is not supplied to the auxiliary heat generating member 6b when it is off. A case where the voltage of the auxiliary power supply 5 is used at 80V is a low power mode, and a case where the voltage of the auxiliary power supply 5 is used at 140V is a high power mode.

FIG. 3 shows a control device 10 for controlling the auxiliary power supply device 5. The control device 10 includes an operation detection unit 11a that detects the operation of the image forming apparatus of the present embodiment, a paper type detection unit 11b that detects the type of paper P on which an image is formed, and a CPU 9 that includes a ROM and a RAM. The CPU 9 selects each power mode (low power mode, high power mode) based on the detection information from the operation detection means 11a and the paper type detection means 11b, and issues a command to the DC / DC converter 7. The DC / DC converter 7 is transmitted and controlled to be in one of an operation state where no transformation is performed, a transformation operation state, or an off state.
Here, the heat generating member 6, the main power supply device 4, the auxiliary power supply device 5, the DC / DC converter 7, and the control device 10 constitute a heating device.

  In the present embodiment, the output power of the auxiliary power supply device 5 is adjusted according to the operation status of the image forming apparatus of the present embodiment, and the size of the fixing device is further reduced as the diameter of the fixing roller 21 is reduced by one auxiliary heating member 6b. By obtaining a heat generation amount corresponding to the two purposes of energy saving, the fixing device 21 can be reduced in size and further energy-saving as the diameter of the fixing roller 21 is reduced.

  In the present embodiment, power from both the main power supply device 4 and the auxiliary power supply device 5 can be simultaneously supplied to the heat generating member 6. Further, since the voltage of the auxiliary power supply device 5 is boosted by the DC / DC converter 7 which is a power adjusting means and supplied to the auxiliary heat generating member 6b, the electric double layer capacitor can be lowered, and the auxiliary power supply device 5 Can be miniaturized.

  In the present embodiment, 1200 W is extracted from the commercial power supply by the main power supply device 4, 1680W is extracted from the auxiliary power supply device 5 in the high power mode at startup, and 540 W is extracted in the low power mode when the paper is passed. The resistance of the heat generating member 6a is about 8Ω, and the resistance of the auxiliary heat generating member 6b is about 11.7Ω. As a result, 2880 W of electric power exceeding the upper limit of the supply power of the commercial power source can be used to raise the temperature of the heating member 21 when the image forming apparatus is started up. In addition, since a maximum of 1740 W of power can be used to raise the temperature of the heating member 21 even during paper feeding, it is possible to handle all types of transfer paper P continuously.

FIG. 4 shows a flow of a program stored in the ROM of the CPU 9 included in the control device 10 according to the present embodiment, and the fixing device control by the control device 10 when the CPU 9 receives a heating member temperature increase command. The flow is shown.
First, the CPU 9 receives the operation information of the image forming apparatus of the present embodiment from the operation detection unit 11a, and from this operation information, it is at the time of temperature rise for starting up the fixing device 20 or because the fixing device 20 is passing paper. Check if the temperature is at the time of heating. The CPU 9 sets the power mode to the high power mode at the time of temperature rise for starting up the fixing device 20 and controls the DC / DC converter 7 so as to boost the voltage of the auxiliary power supply device 5 to 140V. The heating member 21 is heated by the power supplied from the auxiliary power supply 5 and the main power supply 4.

  The CPU 9 also determines the type of the transfer paper P based on the detection information from the paper type detection means 11b that detects the type of the transfer paper P that passes through the fixing device 20 when the temperature of the fixing device 20 is increased to pass the paper. It is determined whether or not the power of the auxiliary power supply 5 is supplied to the auxiliary heat generating member 6b. In this embodiment, when the thickness of the transfer paper P is 0.1 mm or more, the temperature drop of the thin fixing roller 21 becomes a problem when the paper is passed. Therefore, the CPU 9 has a thickness of the transfer paper P of 0.1 mm or more. To determine the type of the transfer paper P, and when the thickness of the transfer paper P is 0.1 mm or more, the power mode is set to the low power mode and the auxiliary power supply device for the DC / DC converter 7 is set. The heating member 21 is heated by the electric power from the auxiliary power supply 5 and the main power supply 4 by controlling the voltage of 5 as it is. When the thickness of the transfer paper P is less than 0.1 mm, the CPU 9 turns off the DC / DC converter 7 to stop the power supply from the auxiliary power supply 5 to the auxiliary heat generating member 6b, and the main power supply 4 The heating member 21 is heated with only electric power.

For this reason, when heating the transfer paper P in which the temperature drop of the thin fixing roller 21 is not a problem, it is possible to prevent wasteful power consumption of the auxiliary power supply device 5 from being consumed.
Here, the lighting control device having a temperature detection means (not shown) for detecting the surface temperature of the heating member 21 heats the heating members 6a and 6b based on the detection information of the surface temperature of the heating member 21 from the temperature detection means. Although the on / off control is performed so that the surface temperature of the member 21 is kept constant, the lighting control device may be incorporated in the control device 10.

  In this embodiment, the fixing device 20 has a very short start-up time of 10 seconds when the surface temperature of the thin fixing roller 21 is raised from 20 ° C. to the preset fixing temperature 180 ° C. Further, by supplying the power of the auxiliary power supply 5 to the auxiliary heat generating member 6b in the low power mode even during paper feeding, the temperature drop of the thin fixing roller 21 during high-speed paper feeding can be prevented, and 1 minute. We were able to achieve 75 sheets.

  In the present embodiment, the voltage of the electric double layer capacitor of the auxiliary power supply device 5 is set to 80V, the voltage is raised to 140V by the DC / DC converter 7 at the start-up, and is supplied to the auxiliary heat generating member 6b as it is at 80V when the paper is passed. The power supply device 5 may use a lower voltage capacitor for miniaturization, and the auxiliary power supply device 5 may boost the output voltage of the auxiliary power supply device 5 to a voltage corresponding to each operation. Conversely, if the voltage of the capacitor of the auxiliary power supply device 5 is further increased and the voltage of the auxiliary power supply device 5 is boosted or lowered by the DC / DC converter 7 corresponding to each operation, the auxiliary power supply device 5 is used. Can be supplied with stable power for a long time.

  In the present embodiment, the DC output from the electric double layer capacitor of the auxiliary power supply device 5 is boosted by the DC / DC converter 7 and input to the auxiliary heat generating member 6b as DC, but when large power exceeding 1000 W is handled by DC. However, there is a problem that the power supply, the switching element of the electric circuit around the heat generating member, and the like are increased in size and cost.

  Therefore, as shown in FIGS. 7A and 7B, a DC / AC converter 8 is provided between the DC / DC converter 7 and the auxiliary heating member 6b, and the output power of the DC / DC converter 7 is converted to the DC / AC converter. By converting the AC power into AC power at 8 and putting it into the auxiliary heat generating member 6b, the switching element of the electric circuit can be reduced in size and cost. In this case, when the DC / DC converter 7 is turned off, the output power of the auxiliary power supply 5 is converted into AC power by the DC / AC converter 8 as shown in FIG. 7A and supplied to the auxiliary heating member 6b. During the operation of the DC converter 7, as shown in FIG. 7B, the output power of the auxiliary power supply 5 is boosted by the DC / DC converter 7 or converted into AC power by the DC / AC converter 8 without being boosted. It is put into the auxiliary heating member 6b.

  In this embodiment, an electric double layer capacitor is used as an auxiliary power supply, but the power of the capacitor is power charged with power from a commercial power source, and the power from the commercial power source is a concentrated type such as thermal power, hydraulic power, nuclear power, etc. This is due to power generation. Since the image forming apparatus is a product that handles corporate and personal information, it is important to ensure its security and supply stable power. The power charged from the commercial power supply to the capacitor etc. can be handled by the backup power supply in an emergency or emergency, but security is ensured and stable power supply is ensured. It ’s hard to say.

  Therefore, by using a power generation element such as a fuel cell for the auxiliary power supply device 5, the image forming apparatus itself has an autonomous power source built in, and security is ensured and stable power supply is ensured. In addition, the fuel cell is cleaner and more energy efficient than a commercial power source that supplies electric power generated by fossil fuel. Therefore, an image forming apparatus that is very environmentally friendly (has no adverse effect) can be provided. Can be provided.

  According to this embodiment, it has the DC / DC converter 7 as a power adjustment means for adjusting the power supplied to the auxiliary power supply device 5 and the detection means 11a for detecting the status of the image forming apparatus. Since the control device 10 that adjusts and controls the supply power of the auxiliary power supply device 5 according to the information is provided, the power of the appropriate auxiliary power supply device can be supplied to the auxiliary heat generating member 6b according to the application.

  According to this embodiment, the electric power of the auxiliary power supply 5 is supplied to the heat generating means 6 provided in the fixing device 20, the resistance heating element as the heat generating means 6, and the DC / DC converter 7 that is a transformer as the power adjusting means. Since the control device 10 adjusts and controls the power supplied to the auxiliary power supply device 5 by the control device 10, the heating device and the fixing device can be started up for a short time. The power of the power supply device can be supplied to the auxiliary heat generating member 6b.

According to the present embodiment, since the transformer device is the DC / DC converter 7, the voltage of the power supplied from the auxiliary power supply device can be adjusted according to the application.
According to the present embodiment, the DC / AC converter 8 changes the power supplied from the auxiliary power supply device 5 to AC power, whereby the switching element of the electric circuit that supplies power to the heat generating member can be downsized.

According to the present embodiment, when the detection information is the operation state of the image forming apparatus, it is possible to supply the power of the auxiliary power supply device 5 appropriate for the operation state of the image forming apparatus to the auxiliary heat generating member 6b. .
According to the present embodiment, since the power supplied from the auxiliary power supply 5 at the time of warm-up (startup) is larger than the power supplied from the auxiliary power supply 5 at the time of paper passing, the power supply can be appropriately set up at the time of short-time startup and paper passing. It is possible to supply power to a simple auxiliary power supply device.

  According to this embodiment, the high power mode in which the power supplied from the auxiliary power supply device is supplied by the first predetermined power, and the low power mode in which the second predetermined power is smaller than the first predetermined power. And the control device 10 switches the mode according to the detection information of the detection means, so that an appropriate power of the auxiliary power supply device can be supplied according to the application.

According to this embodiment, by adjusting the supply power of the auxiliary power supply device according to the type of the recording member P to be passed, it is possible to supply the appropriate power of the auxiliary power supply device according to the type of the recording member P. it can.
According to this embodiment, by using the auxiliary power supply device 5 as a capacitor, the charging time of the auxiliary power supply device can be shortened and the life of the auxiliary power supply device can be extended.

  According to the present embodiment, by using the auxiliary power supply 5 as a fuel cell, it is possible to provide a short-time startup image forming apparatus that does not require charging from the main power supply 4, and to ensure the security of the image forming apparatus. A stable power supply can be ensured. In addition, the fuel cell is cleaner and more energy efficient than a commercial power source that supplies electric power generated by fossil fuel. Therefore, an image forming apparatus that is very environmentally friendly (has no adverse effect) can be provided. Can be provided.

  FIG. 9 shows the configuration of a fixing device and its peripheral circuits in another embodiment of the present invention. In this embodiment, magnetic induction heating means is used as the heat generating means 6 of the fixing device 20 in the above embodiment. The fixing device 20 has a thin fixing roller 21 having a Ni thin layer as a heat generating layer under the release layer, and an induction heating coil 6a as a heat generating member for the main power supply device, an auxiliary power supply device in the fixing roller 21 An induction heating coil 6b is disposed as a heat generating member. Further, the fixing device 20 includes inverter circuits 16a and 16b that pass alternating currents (high-frequency currents) to the induction heating coils 6a and 6b, a rectifier circuit 15 that rectifies an AC voltage from the main power supply device 4, and an auxiliary power supply device 5. DC / DC converter 7 which transforms the voltage of

  The AC voltage from the commercial power supply 4 is rectified by the rectifier circuit 15 and converted to a high frequency by the inverter circuit 16a. The induction heating coil 6a is supplied with a high-frequency current from the inverter circuit 16a to generate a magnetic flux. By this magnetic flux, an eddy current flows to the heat generation layer of the fixing roller 21, and is converted into Joule heat by the skin resistance of the fixing roller 21. As a result, the fixing roller 21 is heated.

  The auxiliary power supply device 5 includes an electric double layer capacitor and a charger that charges the electric double layer capacitor with electric power from the main power supply device 4. The direct current output of the auxiliary power supply device 5 is transformed by the DC / DC converter 7 and then converted into a high-frequency current by the inverter circuit 16b and flows to the induction heating coil 6b. The eddy current is generated by the magnetic flux generated by the induction heating coil 6b. Flows into the heat generation layer of the fixing roller 21 and is converted into Joule heat by the skin resistance of the fixing roller 21, whereby the fixing roller 21 is heated. The recording paper P passes between the fixing roller 21 and the pressure roller 22, and the recording paper P is melted by melting and melting the toner by the fixing roller 21 and the pressure roller 22 heated by the Joule heat. To wear.

  Also in the fixing device of this embodiment, the DC / DC converter 7 which is a power adjusting means is controlled by the control of the control device 10 in the same manner as in the above embodiment, and depending on the type of start-up, paper passing, and heated object. Appropriate supply power can be supplied from the auxiliary power supply 5 to the heat generating means 6.

  In the present embodiment, since the magnetic induction heating means is used as the heat generating means 6, the heating efficiency can be increased as compared with the case where a resistance heating element is used as the heat generating means 6. Further, in this embodiment, the induction heating coils 6a and 6b are placed in the fixing roller 21, but the diameter of the fixing roller 21 can be further reduced by taking the induction heating coils 6a and 6b out of the fixing roller 21. it can.

  In this embodiment, the induction heating coil 6b for the auxiliary power supply device and the high-frequency inverter 16b are prepared, but power is simultaneously supplied to the induction heating coil 6a for the main power supply device and the induction heating coil 6b for the auxiliary power supply device. In this case, there is a problem of generating an interference sound due to a frequency difference between the high-frequency currents of the induction heating coils 6a and 6b. Further, there is an influence of mutual induction of the induction heating coils 6a and 6b, which affects the temperature distribution of the fixing roller 21. Therefore, the heating of the fixing roller 21 may be performed by superimposing the power of the auxiliary power supply 5 on the power of the main power supply 4 and supplying it to the induction heating coil 6a. Since the AC voltage from the main power supply device 4 is rectified and input by the rectifier circuit 15 to the high-frequency inverter 16a, it is easy to superimpose the DC power of the auxiliary power supply device 5 on the output of the rectifier circuit 15. As a result, there is no problem of interference noise and mutual induction, and only one high-frequency inverter and induction coil are required. Therefore, it is possible to provide a low-cost magnetic induction heating device and fixing device.

According to this embodiment, the diameter of the fixing roller can be reduced, and further energy saving associated with a reduction in heat capacity can be achieved.
According to this embodiment, since the heat generating means 6 is a magnetic induction heating means, a heating device and a fixing device with high heating efficiency can be provided.
According to the present embodiment, by supplying the power generated by superimposing the power of the auxiliary power supply and the power of the main power supply to the heat generating means 6, the main power supply and the auxiliary power supply share the induction heating coil and the high-frequency inverter. In addition, it is possible to provide a small-sized magnetic induction heating device with a short start-up time and low cost.
The present invention can be applied to a heating device using electric energy as a main energy source other than the fixing device.

1 is a block diagram illustrating a circuit configuration of a fixing device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a cross section of the fixing device in the same embodiment. It is a block diagram which shows the control apparatus which controls the auxiliary power supply in the embodiment. 3 is a flowchart showing a fixing device control flow of the embodiment. It is sectional drawing which shows each conventional example of the fixing device using the electric power by an auxiliary power supply device. FIG. 6 is a characteristic diagram illustrating a heating time of a heating member when only the main power supply is used in the fixing device and when the main power supply and the auxiliary power supply are used simultaneously. It is a block diagram which shows the case where a DC / AC converter is used in the said embodiment. It is sectional drawing which shows the said embodiment. It is a block diagram which shows the structure of the fixing device in other embodiment of this invention, and its peripheral circuit.

Explanation of symbols

4 Main power supply device 5 Auxiliary power supply device 6, 6a, 6b Heating member 7 DC / DC converter
10 Control unit
11a Motion detection means
11b Paper detection means 8 DC / AC converter
15 Rectifier circuit
16a, 16b high frequency inverter

Claims (14)

  In a heating device that generates heat from power supplied from a main power supply or an auxiliary power supply, a power adjustment means that adjusts the power supplied to the auxiliary power supply and a control that controls the power adjustment means according to external information And a heating device.   2. The heating device according to claim 1, wherein the heating unit includes a resistance heating element, the power adjustment unit includes a transformer, and the control device controls the power adjustment unit to supply power to the auxiliary power supply device. A heating device characterized by adjusting the temperature.   3. The image forming apparatus according to claim 2, wherein the transformer is a DC / DC converter.   3. The heating apparatus according to claim 1, further comprising a DC / AC converter that converts DC power into AC power and supplies the AC power to the heat generating means.   2. The heating apparatus according to claim 1, wherein the heat generating means is a magnetic induction heating means.   6. The heating apparatus according to claim 1, wherein the external information is information indicating an operation state of the image forming apparatus.   7. The heating device according to claim 6, wherein the power supplied to the auxiliary power device during warm-up is greater than the power supplied to the auxiliary power device when the heating means heats the object to be heated. .   8. The heating device according to claim 1, wherein a high power mode for supplying power supplied from the auxiliary power device with a first predetermined power and a power supplied from the auxiliary power device to the first power source are provided. A heating device, characterized in that it has a low power mode that is supplied with a second predetermined power smaller than the predetermined power, and the control device switches the mode according to the external information.   9. The heating apparatus according to claim 1, wherein the power supplied to the auxiliary power supply device is adjusted according to the type of the object to be heated.   10. The heating device according to claim 1, wherein the auxiliary power supply device is a capacitor.   10. The heating device according to claim 1, wherein the auxiliary power supply device is a fuel cell.   In the magnetic induction heating device that supplies the power of the main power supply device capable of steady power supply and the power of the auxiliary power supply device to the heat generating portion, the power obtained by superimposing the power of the auxiliary power supply device and the power of the main power supply device Is supplied to the heat generating part.   A fixing device comprising: the heating device according to any one of claims 1 to 11 or the heating device according to claim 12; and a fixing unit heated by the heating device.   An image forming apparatus comprising the fixing device according to claim 13.

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