JP5240344B2 - Image forming apparatus - Google Patents

Description

The present invention relates to images forming apparatus having a current supplying means for supplying a current to the heating element and which is different from the power requesting unit.

  An image forming apparatus represented by a copying machine, a printer, a FAX, or a complex machine of these, forms an image on a sheet-like recording material such as paper or OHP, and transfers the image to the recording material. . There are various types of image recording methods used in image forming apparatuses. Among them, the electrophotographic method is widely used in the above-mentioned apparatuses in terms of high speed, image quality, cost, and the like. .

  In the electrophotographic system, a fixing device is generally used to fix an unfixed toner image transferred onto a recording material onto the recording material with heat and pressure. As a fixing method using a fixing device, a heat roller method is currently most frequently used in terms of high speed and safety. The heat roller system is a counter rotating body that forms a mutual pressure contact portion called a pressure nip portion that is disposed in opposition to a heating member such as a heating roller that is heated by a heat generating member such as a halogen heater and is pressed against the heating member. In between, the recording material that is to be heated as viewed from the heating member is passed and heated. As the heating member, a metal roller in which iron, aluminum or the like is used as a core is mainly used, and its heat capacity is increased. For this reason, in order to raise the temperature to about 180 ° C., which is a temperature at which the toner can be melted and used (fixing temperature), a long rise time of several minutes to ten and several minutes is required.

  Therefore, in the image forming apparatus, even when the apparatus user is not performing printing, power is supplied to the heat generating member provided in the heating member, and the temperature is kept at a preheating temperature slightly lower than the usable temperature (fixing temperature). . Thus, the so-called first print time is shortened so that the heating roller immediately rises to a usable temperature (fixing temperature).

  If the rise in temperature is emphasized in this way, even when the apparatus is not used, it is not necessary directly for image formation, so to speak, extra power is consumed by the heating member as standby power. There is also a survey result that the standby consumption energy accounts for 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 amended 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 energy consumption during standby in image forming devices has a large energy saving effect, and there is a demand for zero power supply when the device is in standby mode. Yes.

  If the power of the apparatus is set to zero while maintaining the conventional fixing device configuration, it takes time to raise the temperature of the heating roller at the time of restarting, and the standby time is long and the usability of the apparatus deteriorates. End up. For this reason, a configuration in which the temperature of the heating roller is quickly increased is required to realize energy saving in the image forming apparatus. For example, in the ZESM, there is a demand for extremely strict content that the apparatus once stands up and the restart time from a so-called standby state such as a sleep state is set to 10 seconds or less.

  In order to shorten the temperature raising time, it is conceivable to reduce the heat capacity of the heating member or increase the input power to the heating member (heat generating member). Regarding the reduction of the heat capacity, the thickness of the heating roller or fixing roller as the heating means is reduced from the conventional several mm to 1 mm or less, or by using a film or a belt member as the heating means, 50 cpm (50 sheets / 1) In a medium / low speed printing speed range of about (min), a rise in a short time of about 10 to 30 seconds is realized, and the temperature raising time can be shortened.

  On the other hand, in order to increase the input power to the heating means, the supply voltage or the supply voltage may be increased. However, a commercial power source such as a general office outlet in Japan is generally 100 V / 15 A (ampere). In fact, since 1500 W is the upper limit of the supply power, it is difficult to increase the supply power to the heating means with a general commercial power source alone.

  In such a medium / low speed printing speed range, lowering the heat capacity of the heating means is effective for raising the temperature in a short time, but in a high speed printing speed range of 60 cpm (60 sheets / min) or more, per unit time Since the recording material passes through a large number of sheets, the recording material takes more heat from the heating unit than the heating unit heats. If the heat capacity of the heating member is small, the temperature of the heating unit is maintained at a predetermined temperature. It was difficult. In the image forming apparatus, such a temperature maintenance, that is, a temperature drop of the heating means causes a fixing defect.

  In order to solve this problem, some image forming apparatuses that can handle printing speeds up to a high speed range include a device that supplies a large amount of power with a power supply voltage of 200 V. However, it is necessary to perform special work on the power supply at the installation site. Yes, it's not a general solution. In addition, a product that raises the total input power amount by using two systems of 100V15A has been put into practical use, but it is difficult to install unless the outlets of the two systems are nearby. For this reason, until now, even if an attempt is made to raise the temperature of the heating roller (heating means) in a short time, the upper limit of the input energy has not been raised.

  Against this background, as a technique for increasing the maximum power supply amount and preventing the temperature of the fixing device from being lowered, an image forming apparatus having a chargeable auxiliary power supply device different from the commercial power supply (100V-15A) has been proposed. ing. For example, in Patent Document 1, as shown in FIG. 15, a heating unit includes a plurality of heaters as heat generating members, one of the heat generating members is supplied with electric power from a commercial power source serving as a main power supply device, and the other heat generating member. The member is supplied with electric power from the auxiliary power supply device to increase the maximum power supply amount to the heating means, thereby shortening the rise time and preventing the temperature from decreasing. Secondary batteries such as lead-acid batteries and CADNICA batteries are typical examples of auxiliary power supply devices. However, when secondary batteries are repeatedly charged and discharged, the battery deteriorates and its capacity decreases, and discharges with a large current. The longer the service life, the shorter the life.

  Even in a CADNICA battery, which is generally considered to have a long life with a large current, the number of charge / discharge cycles is about 500 to 1000 times. For example, if the charge / discharge cycle is repeated 20 times a day, the battery life is about one month. Will come. This takes time to replace the battery, and the running cost such as battery cost is very high. Furthermore, from the viewpoint of charging time, it takes time to charge a large capacity, and therefore it cannot be used for applications in which charging and discharging are repeated many times a day, and it has been difficult to realize practically. Although it is possible to increase the number of repetitions by increasing the capacity of the secondary battery and using the charge / discharge cycle shallowly, it is difficult to put it to practical use because of the long time required for charge / discharge. As described above, since the secondary battery has practical problems, it is also described in Patent Document 1 that a large-capacity capacitor such as an electric double layer capacitor is used as the auxiliary power supply device.

  The large-capacity capacitor has the following advantageous characteristics as compared with the battery. First, the number of repetitions of charging and discharging is almost unlimited at tens of thousands or more, charging characteristics are hardly deteriorated, and regular maintenance is unnecessary. Secondly, it takes several seconds to several tens of seconds while the charging time of a secondary battery requires several hours. In addition, the electric double layer capacitor can flow a large current of several tens to hundred amperes, and can supply power in a short time.

  Patent document 2 is mentioned as another form which employ | adopts an auxiliary power supply system. In Patent Document 2, as shown in FIG. 17, there is a power supply device that supplies DC 5V, 24V, etc. from a commercial power supply (100V-15A) to the image forming apparatus, and a charging device that supplies power from a rechargeable battery as an auxiliary power supply device. In addition, the power supplied from both is supplied to the main control unit, thereby reducing the load on the power supply device by the amount of power supplied by the rechargeable battery, and realizing the maximum power reduction of the power supply device.

  In the method of supplying auxiliary power to the auxiliary heater as in Patent Document 1, an auxiliary heater is required in addition to the main heater as a heat generating member of the heating unit, and there is a limit in reducing the size of the heating unit. In addition, as shown in FIG. 16, high power (for example, 1900 W), which is the sum of the maximum power (for example, 1200 W) of the main heater serving as the main heat generating portion and the maximum power (for example, 700 W) of the auxiliary heater, can be supplied to the heat generating member. In the case of the heating means having a low heat capacity in consideration of the start-up property, it is considered that an excessive temperature rise is caused when the device runs away for any reason.

  In Patent Document 2, since a power is always supplied during an image forming operation using a battery having a sufficient margin for the stored current, a sufficient stored current is required. For this reason, it is difficult to use an electricity storage device having a relatively small capacity, such as an electric double layer capacitor, and an electricity storage device such as a capacitor that cannot secure a sufficient capacity cannot be used as an auxiliary power supply device, and the storage current of the battery can be reduced. Therefore, it is difficult to reduce the size of the power storage device, and it is not suitable for application to an image forming apparatus with a short-time temperature rise or a high printing speed. When the image forming apparatus includes a hard disk device (HDD) or a device such as a staple, power is supplied from the auxiliary power supply device to a specific device that instantaneously requires power, such as a hard disk device or a staple. In application, it is difficult to increase the supply current to the heating means, and it is not suitable for application to an image forming apparatus with a short temperature increase or a high printing speed.

  In addition, as shown in FIG. 18, even when power is required instantaneously such as activation of a hard disk device (HDD) or stapling, the required power supply is performed by supplying power from an auxiliary power source. Although it is possible to realize a system within the limited power, it is difficult to increase the amount of power supplied to the fixing device in such an application where auxiliary power is supplied to a specific device. Cannot be realized.

The present invention is highly safe compact while allowing heated in a short time by increasing the power available to the heating means, to provide a corresponding possible images forming device also to faster printing speed, the purpose And

To achieve the above object, the image forming unit for transferring a toner image, a fixing device for fixing the toner image on a recording material, a heating member for heating a heating member of the fixing device, and the heating member according to claim 1. In an image forming apparatus comprising: a current supply unit that supplies current to a power request unit other than the power supply unit; and a control unit that controls power supply from the power supply unit to the heat generating member and the power request unit. provided with a power supply and an auxiliary power unit is a power storage device, has a heat generation state detecting means for detecting the state of the heating member, control means, when the continuous paper feed, electric power to the heating member from only the main power supply A first power supply mode in which power is supplied simultaneously from both the main power supply device and the auxiliary power supply device to a power requesting unit comprising a plurality of drive systems, and the power requesting unit and the plurality of drive systems from only the main power supply device From Supplying power to the heat generating member that, the electric power supplied to the heating member and a second power supply mode for less than the rated power of the heating member, the amount of power supplied to the heating member in the first power supply mode Is set to be larger than the amount of power supplied to the heat generating member in the second power supply mode, the state of the heat generating member is the temperature state of the heating member heated by the heat generating member, and the control means When the temperature of the heating member detected by the detection means is equal to or higher than a predetermined temperature, the first power supply mode is switched to the second power supply mode, and the amount of power supplied from the auxiliary power supply device to the power request unit is suppressed. It is characterized by controlling as follows.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the power requesting unit has a plurality of power load devices, the control unit simultaneously supplies power to the plurality of power load devices in the first power supply mode. It is characterized in that.

The invention according to claim 3, the constant in the image forming apparatus according to claim 1, wherein, when power demand unit having a plurality of power load devices, the control means, said plurality of power loads device when the first power supply mode Power is supplied through the voltage circuit heat generation control means .

According to a fourth aspect of the present invention, in the image forming apparatus according to the first, second, or third aspect, the auxiliary power supply device includes a plurality of capacitors .

According to the present invention, a first power supply mode for supplying power to the heat generating member only from the main power supply device and supplying power to the power requesting unit and the image forming unit from both the main power supply device and the auxiliary power supply device; A power supply to the heat generating member only from the main power supply device, and a second power supply mode in which the power supplied to the heat generating member is less than the rated power of the heat generating member, and the state of the heat generating member is heated by the heat generating member When the temperature of the heating member is the temperature state of the heating member and the temperature of the heating member detected by the heat generation state detection unit is equal to or higher than a predetermined temperature, the control unit switches the first power supply mode to the second power supply mode and assists Since control is performed so as to suppress the amount of power supplied from the power supply device to the power request unit, auxiliary heating means supplied with power from the auxiliary power supply device is not necessary, and the maximum power of the heat generating member can be reduced, and the device can be downsized. The figure While, it is possible to enhance the safety. In addition, since the heat generating member does not receive power supply from the auxiliary power supply device, the amount of power required for the auxiliary power supply device can be reduced, and when the auxiliary power supply device includes a plurality of capacitors, one The capacity of the capacitor can be increased to reduce the number of cells, and the size can be further reduced.

  According to the present invention, the heat generation state detection unit that detects the state of the heat generation member is provided, and the amount of power supplied from the auxiliary power supply device to the power request unit and the image forming unit is changed according to detection information from the heat generation state detection unit. Therefore, it is possible to reduce the use of power at the power requesting unit and the image forming unit after securing the supply power to the heat generating member, and to use the power appropriately.

  According to the present invention, when the state of the heating member is the temperature state of the heating member heated by the heating member, and the control means detects that the temperature of the heating member detected by the heating state detection means is equal to or higher than a predetermined temperature. Since control is performed so as to reduce the amount of power supplied from the auxiliary power supply to the power requesting unit and the image forming unit, unnecessary power use of the auxiliary power supply can be reduced, and the charging time of the auxiliary power supply can be reduced. .

1 is a schematic configuration diagram illustrating an embodiment of an image forming apparatus to which the present invention is applied. 1 is a cross-sectional view showing an embodiment of a roller fixing type fixing device to which the present invention is applied. 1 is a cross-sectional view showing an embodiment of a belt fixing type fixing device to which the present invention is applied. It is sectional drawing which shows one form of the heating means comprised by the magnetic flux generation means. (A) is a diagram in which the heat generating members are arranged in substantially the entire region in the roller axial direction, and (b) is a diagram in which the heat generating members are arranged in the roller axial direction. FIG. 3 is a block diagram illustrating a relationship between a heating device, a fixing device fed from the heating device, and a drive system as a power request unit of the image forming apparatus. It is a figure which shows the electric power feeding pattern which uses an auxiliary power supply device at the time of paper passing. FIG. 6 is a diagram illustrating a relationship between power fluctuation on the power supply unit side, power consumption on the image forming apparatus side, and temperature fluctuation of the heating roller. It is a figure which shows the temperature characteristic of the heating member by the difference in the electric power supply means at the time of paper passing. It is a figure which shows the electric power feeding pattern which uses an auxiliary power supply device from the time of starting. FIG. 4 is a diagram illustrating a relationship between power fluctuation on the power supply unit side, power consumption on the image forming apparatus side, and temperature fluctuation of a heating member. It is a figure which shows the temperature characteristic of the heating member by the difference in an electric power supply means. It is a figure which shows another form of the electric power feeding pattern using an auxiliary power supply device. FIG. 5 is a block diagram showing another form of a heating device, a fixing device fed from the heating device, and a drive system as a power request unit of the image forming apparatus. It is a block diagram which shows the structure of the conventional heating power source provided with the main heat generating member and the sub heat generating member, and the relationship of a power feeding destination. It is a figure which shows the conventional electric power feeding pattern by the structure of FIG. FIG. 6 is a block diagram showing a relationship between a configuration of a conventional heating power supply that supplies power from a main power supply device to a heat generating member and a drive system of an image forming apparatus, and a power supply destination. It is a figure which shows the conventional electric power feeding pattern by the structure of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of an image forming apparatus as an example of an apparatus to which the present invention is applied. In FIG. 1, the image forming apparatus includes a drum-shaped photoconductor 41 as an electrostatic latent image carrier (image carrier) inside the main body. The photoreceptor 41 is configured to be rotationally driven in a clockwise direction indicated by an arrow in the drawing by a drive motor (not shown). Around the photosensitive member 41, a charging device 42 for uniformly charging the surface of the photosensitive member, a developing device 44 having a developing roller 44a for developing a latent image on the photosensitive member, and an image (toner image) on the photosensitive member are recorded. A transfer device 48 that is a material and is transferred to a sheet P as a heated body, and a cleaning device 46 that cleans the surface of the photoconductor is disposed in the rotation direction of the photoconductor 41.

  On the surface of the photoreceptor 41 uniformly charged by the charging device 42, the writing laser beam Lb is reflected by the reflecting mirror 43 and irradiated as exposure light to the exposure unit 150 between the charging device 42 and the developing device 44. Is done. As a result, a latent image is formed on the surface of the photoreceptor. The writing system laser beam Lb is emitted from a well-known writing unit including a reflecting mirror 43 and a polygon not shown. The latent image formed on the surface of the photosensitive member is visualized by the supply of toner as a developer (also referred to as developer) by the developing roller 44a of the developing device 44.

  The transfer device 48 is disposed to face the surface of the photoreceptor, and a transfer portion 47 is formed between the two. The sheet P is conveyed to the transfer unit 47 from a sheet feeding tray 51 of the sheet feeding device 50 via a sheet feeding roller 110 and a registration roller pair 49 that constitute a conveying system. A visible image (toner image) on the photoreceptor 41 is electrostatically transferred to the conveyed paper P by a transfer bias applied from the transfer device 48 in the transfer unit 47.

  The paper P on which the visible image (toner image) is transferred is appropriately conveyed to a fixing device 10 disposed downstream of the transfer unit 47 by a conveyance roller (not shown) that constitutes a conveyance system (not shown). The fixing device 10 is provided on a paper conveyance path indicated by a broken line in the drawing, and is opposed to the heating roller 1 which is a heating member and a fixing member which is heated by receiving power supply from a power supply control device 200 which will be described later. A pressure roller 7 is provided as a counter rotating body arranged. The heating roller 1 and the pressure roller 7 are in contact with each other to form a pressure contact nip portion 52 for fixing. When the paper P transported to the fixing device 10 passes through the nip portion 52, it is thermally fixed to the paper P by heat from the heating roller 1 and pressure applied to the pressure nip portion 52, and is placed on a paper discharge tray (not shown). Discharged.

  Residual toner remaining on the photoreceptor 41 without being transferred to the paper P by the transfer unit 47 reaches the cleaning device 46 as the photoreceptor 41 rotates. Then, when passing between the cleaning member 46a of the cleaning device 46 and the photosensitive member 42, the cleaning member 46a scrapes off and cleans.

  The fixing device and related components will be described. As the fixing device, there are a roller fixing method shown in FIG. 2 and a belt fixing method shown in FIG. Although the roller fixing method shown in FIG. 2 is used for the fixing device 10 of the image forming apparatus shown in FIG. 1, the belt fixing method shown in FIG. 3 may be used.

  The fixing device 10 includes a heating roller 1 that is rotated by a driving source (not shown), and a pressure roller 7 that presses against the outer peripheral surface of the heating roller 1 to form a pressure nip portion 52. The toner image is fixed to the paper P with heat and pressure by introducing the paper P to which the toner has been transferred and sandwiching and conveying it. The heating roller 1 includes a halogen heater 60 as a heat generating member therein, and the surface of the heating roller 1 is heated to a fixing temperature as a predetermined temperature when electric power is supplied to the halogen heater 60 to generate heat. . In FIG. 2, a symbol T indicates a toner image before fixing.

  A belt fixing type fixing device 100 shown in FIG. 3 includes a fixing belt 101 as a fixing member constituted by an endless belt, a fixing roller 102 and a heating roller 103 as a plurality of backup members around which the fixing belt 101 is wound, A pressure roller 104 is provided as a counter rotating member that forms a pressure contact nip 52 between the fixing belt 101 and the fixing roller 102 as one of the rollers, and the toner image T is transferred to the pressure nip 52. The toner image T is fixed to the paper P by heat and pressure by introducing the paper P as a recording material and carrying it in a sandwiched manner. The heating roller 103 includes a halogen heater 60 as a heat generating member therein, and constitutes a heating member. The heating roller 103 is heated by the electric power supplied to the halogen heater 60, thereby raising the temperature of the surface of the fixing belt 100 to a fixing temperature as a predetermined temperature via the roller. In the fixing device 100, in order to convey the paper P, the fixing roller 102 and the pressure roller 104 are configured to receive a driving force from a driving motor serving as a driving source (not shown). Therefore, in FIG. 3, the fixing roller 102 is rotated in the clockwise direction, the fixing belt 101 is also rotated in the same direction, and the pressure roller 104 is rotated in the counterclockwise direction. As a driving form, either the fixing roller 101 or the pressure roller 104 may be driven to rotate by receiving a driving force.

  As shown in FIG. 2, the heating roller 1 includes a halogen heater 60 inside a cylindrical roller base 63 made of metal. The halogen heater 60 is configured to raise the roller surface temperature by heating the roller base 63 with the radiant heat. Since the roller base 63 functions as the base of the heating roller 1, it is desirable that the roller base 63 is made of metal such as aluminum or iron in view of durability and deformation due to pressure. In this embodiment, a release layer 1a for preventing adhesion of toner or the like is formed on the outer peripheral surface of the roller base 63 serving as the roller surface. It is desirable that the inner surface of the roller, that is, the inner peripheral surface of the roller base 63 is subjected to a blackening process for efficiently absorbing the heat of the halogen heater. The pressure roller 7 is formed with an elastic layer 7b such as rubber on the outer periphery of the metal core 7a, and is configured to be elastically deformed when pressed against the heating roller 1 so that the pressure nip portion 52 is sufficiently formed. ing.

  As shown in FIG. 3, the heating roller 103 has a smaller diameter than the fixing roller 102. The heating roller 103 includes a halogen heater 60 inside a cylindrical roller base 103a made of metal. The halogen heater 60 is configured to heat the roller base 103a with its radiant heat to raise the temperature of the roller surface and to heat the fixing belt 101. Since the heating roller 103 does not face the pressure roller 104 and functions to apply tension to the fixing belt 101, the roller base 103a is thinner than the heating roller 1 in FIG. For this reason, since the metal portion has a small diameter and is thinned, its heat capacity is made smaller than that of the heating roller 1. For this reason, the conventional auxiliary heater becomes unnecessary. It is desirable that the inner surface of the roller, that is, the inner peripheral surface of the roller base 103a, be subjected to a blackening process for efficiently absorbing the heat of the halogen heater 60. The pressure roller 104 is formed such that an elastic layer 104b such as rubber is formed on the outer periphery of the core metal 104a, and is elastically deformed when pressed against the heating roller 102 so that the pressure nip portion 52 is sufficiently formed. ing.

  In this embodiment, one halogen heater 60 having a power of 1200 W at 100 V is used. The halogen heater 60 may be provided in the entire area in the axial direction of each roller as shown in FIG. 5A, or the first heater 61 that heats only the central part of each roller as shown in FIG. 5B. And a second heater 62 that heats only both ends of the roller may be provided, and power supply to the heater may be controlled according to the paper size to prevent the temperature rise of the non-sheet passing portion. In this case, although there are a plurality of heat generating members, either one does not function as an auxiliary heater, but both function as a main heater.

  In this embodiment, each heating member is heated by the halogen heater 60 as a heat generating member, but the heating form is not limited to such a form. For example, a plate-like ceramic heater may be disposed inside each roller. Alternatively, as shown in FIG. 4, a magnetic flux generating means 700 is configured by winding a coil 702 around an arc-shaped core 701, and a high frequency is passed through the coil 702 to inductively heat the core 701 with an alternating magnetic field to raise the temperature. It is good also as a structure. In this case, the heating member becomes the coil 602 and the heat generating member becomes the core 701. As such a heating mode, the heating roller 103 itself may not be heated.

  The merit of using the magnetic flux generation means 700 as a heating means is that on / off control, phase control, or zero cross control is generally used to adjust the electric power of the halogen heater 60, but the output control has both on time and off time. This is a method for adjusting the average power. For this reason, it is preferable in terms of temperature rise characteristics (rise characteristics), but it is difficult to strictly adjust the power. On the other hand, the induction overheating configuration has an advantage that power adjustment is easy because the output power for heating can be changed by changing the frequency to the coil 702.

  Next, the configuration of the heat generation control means 200 and the heating device 300 will be described. In this embodiment, an example in which the heating roller 1 of the fixing device 10 of the roller fixing system shown in FIG. 2 is heated will be described. However, the heating roller 103 of the fixing device 100 may be heated.

  As shown in FIG. 1, the image forming apparatus includes a heat generation control unit 200 and a heating device 400. As shown in FIG. 6, the heating device 400 supplies current to the heating roller 1 including the halogen heater 60 that generates heat by supplying power, and to a plurality of drive systems 300 that are power request units that consume power and serve as image forming units. Current supply means 500 for supplying power and control means 600 for controlling the power supply means 500.

  The power supply means 500 includes a main power supply device 2 and an auxiliary power supply device 3 that is a power storage device as a plurality of power supply means, a charger 4 to the auxiliary power supply device 3, a voltage adjustment circuit 5 as a constant voltage circuit, and a charge / discharge switching means. Sw1 and a known switch element 6 such as a triac as a main power control means for controlling power supply from the main power supply device 2 and a power distribution means 9 are provided.

  The main power supply 2 obtains electric power from the outlet of the commercial power supply 202 via the plug 201 shown in FIG. 1, and supplies power to the halogen heater 60 and a plurality of drive systems 300 as power request units of the image forming apparatus. In Japan, the current capacity is limited to about 15 A at a voltage of 100 V, so the maximum power of the power from the main power supply 2 is about 1500 W.

  The auxiliary power supply 3 is configured by connecting a plurality of capacitor cells made of electric double layer capacitors. The auxiliary power supply device 3 is configured such that the charge / discharge switching means sw1 is switched at an arbitrary timing when a larger amount of power supply is desired, such as when the device is started up or during continuous paper feeding, for the stored power charged from the main power supply device 2. It is configured to supply power to the plurality of drive systems 300 that is supplied with discharge and exceeds the power supplied from the main power supply device 2.

  In this embodiment, as the power storage device used for the auxiliary power supply device 3, an electric double layer capacitor that is a large-capacity capacitor among the capacitors 5 is used. Large-capacity capacitors have also been called electrochemical capacitors, and can be classified into several types, such as electric double layer capacitors and pseudo capacitors, depending on the operating principle. It is desirable to do. Unlike a secondary battery which is another form of the storage-type auxiliary power supply device 3, the capacitor has the following excellent characteristics because it does not involve a chemical reaction.

  When a general nickel-cadmium battery as a secondary battery is used as the auxiliary power supply device 3, it takes several hours even if rapid charging is performed. It cannot be realized and is not practical. On the other hand, when a capacitor is used as the auxiliary power supply device 3, rapid charging of several tens of seconds to several minutes is possible. Therefore, the number of times of heating using the auxiliary power supply device 3 is increased to a practical number. Can do.

  Since the nickel-cadmium battery has 500 to 1000 charge / discharge cycles, it has a short life as an auxiliary power supply device for heating, and there is a problem in labor and cost of replacement. On the other hand, the storage-type auxiliary power supply device 3 using a capacitor generally has a characteristic that it can be discharged and charged 10,000 times or more and has a long life, and is less deteriorated by repeated charging and discharging. Also, unlike lead-acid batteries, there is no need for liquid replacement or replenishment, so little maintenance is required. Since the electric double layer capacitor has an internal resistance of 5 mΩ or less, which is smaller than that of a storage battery, it can be used with a large current exceeding 20 A, and has a lower loss and higher power than a secondary battery such as a lithium battery or nickel metal hydride battery. Easy to get. In recent years, electric double layer capacitors have been developed that can store a large amount of electric energy, and their use in electric vehicles and the like is also being studied. For example, an electric double layer capacitor developed by Nippon Chemi-Con Co., Ltd. has a capacitance of about 2000F at 2.5V. JEOL has also announced a technology called a nano-gate capacitor with a withstand voltage increased to 3.2 to 3.5 V and a power density of 50 to 75 wh / kg, which is 5 to 10 times that of the prior art.

  In the charger 4, voltage adjustment and AC / DC conversion of the main power supply device power corresponding to the auxiliary power supply device 3 is performed, and power is supplied to the auxiliary power supply device 3 to store electricity. The heating device 400 includes an operation state detection unit 3a that is connected to the control unit 600 and detects an operation state of the power request unit. The operation state of the device is the remaining power of the auxiliary power supply 3, and the operation state detection unit 3 a detects the remaining power of the auxiliary power supply 3. That is, the charging state of the auxiliary power supply device 3 is detected by the operation state detecting unit 3a. When the control unit 600 detects that the charging is sufficiently performed, the charging is stopped, and when it is determined that the stored current is small, the charging is performed. Controlled to start. That is, the operation state detection unit 3a also functions as an auxiliary power supply state detection unit that detects the state of the auxiliary power supply device 3.

  In this embodiment, the auxiliary power supply device 3 is configured as a 20 V module in which eight capacitor cells having a rating of 2.5 V to 1200 F, an internal resistance of 5 mΩ or less, and a length of about 120 mm are connected in series. In order to ensure the voltage balance of each cell when connected in series, it is possible to ensure long-term stability of operation by providing a voltage balance circuit (not shown). The auxiliary power supply 3 starts power supply at 200 w from the fully charged state of 20 V, and the control unit 600 stops the discharge when the voltage is detected by the operation state detecting unit 3 a and discharged to about 10 V, which is half.

  The amount of power supplied from the auxiliary power supply 3 is lower than the rated power of the halogen heater 60. Furthermore, the maximum rated power (1200 W) of the halogen heater 60 and the auxiliary power supply 3 shown in FIG. 7 are not used. It is configured to supply power within a difference (300 W = 1200 W−900 W) from the power Wfu_run (900 W).

  The voltage adjustment circuit 5 has a transformer such as a DC / DC converter, and is configured to adjust the output power from the auxiliary power supply device 3 to a predetermined voltage corresponding to the load on the image forming apparatus side. The voltage adjustment circuit 5 supplies power from the main power supply device 2 to a plurality of drive systems 300 other than the fixing device 10. The voltage adjustment circuit 5 uses a constant voltage output of DC24V that supplies power to a device with relatively large power consumption, such as a motor, by a plurality of drive systems 300. However, the voltage adjustment circuit 5 is not limited to a constant voltage, and the load input tolerance of the drive system 300 When the voltage range is wide, the voltage may be varied accordingly.

  In the above-described configuration, the voltage adjustment circuit 5 outputs eight 2.5V rated cells and outputs a range from 20V to 10V to 24V. For this reason, the DC / DC converter 5 is a booster circuit. Even when the amount of power is increased, even if 12 lines are output in the range of 30V to 15V to 24V, the functions of step-up and step-down are provided, while the structure of 20 lines has the function of step-down outputting 24V to the range of 50V to 25V. It does not matter if it is configured. In particular, when a configuration with a large output power of 400 W or more is used, in a low voltage region of about 10 V, the current output from the capacitor increases, so that loss increases, and it is desirable to use a step-up / step-down or step-down configuration. Since the circuit of the DC / DC converter 5 can be simplified, it can be said that a step-down configuration is more desirable.

  The switch element 6 is connected to the control means 600, and is energized to the halogen heater 60 by being turned on by the control means 600, and is continuously turned on / off so that the halogen heater is turned on. The amount of heat generated is adjusted by controlling the total energization flow to 60.

  The power distribution unit 7 is connected to the control unit 600 and is configured to switch the power supply from the main power supply device 2 and the power supply from the auxiliary power supply device 3 to the plurality of drive systems 300 by the control unit 600. That is, when there is remaining power in the auxiliary power supply 3, power is supplied from the auxiliary power supply 3 to the hard disk drive (HDD) 301 and the transport drive system 302 among the plurality of drive systems 300. When the power is lost, switching control is performed so that power is supplied from the main power supply device 2. For this reason, it is possible to always supply necessary electric power to the hard disk device (HDD) 301 and the transport drive system 302 and to set the drive state. On the other hand, among the plurality of drive systems 300, each drive system other than the hard disk drive (HDD) 301 and the transport drive system 302 cannot receive power from the auxiliary power supply device 3, and always receives power from the main power supply device 2. It is configured to be driven by power feeding.

  The control unit 600 includes a known computer arithmetic circuit, and includes a storage unit such as a ROM and a RAM (not shown), and a connector connected to each device and sensor. The control unit 600 supplies power to the halogen heater 60 only from the main power supply device 2 and also includes a first power supply mode for supplying power to the plurality of drive systems 300 from both the main power supply device 2 and the auxiliary power supply device 3. In addition, power is supplied to the plurality of drive systems 300 from only the main power supply device 2, and power is supplied to the halogen heater 60 from only the main power supply device 2. The second power supply mode is smaller than 1200 w) in the embodiment. The control means 600 is set so that the power supplied to the halogen heater 60 in the first power supply mode is larger than the power supplied to the halogen heater 60 in the second power supply mode. The control means 600 is configured to control the power supplied to the halogen heater 60 in the first power supply mode to be smaller than the maximum rated power (1200 W) of the halogen heater 60.

  The control unit 600 includes a heat generation state detection unit 8 that detects the heat generation state of the heating roller 1. The heat generation state detection unit 8 is a temperature sensor that detects the surface temperature of the heating roller 1, and transmits the detection result to the control unit 600. The control unit 600 is configured to change the amount of power supplied from the auxiliary power supply device 3 to the plurality of drive systems 300 according to the detection information of the heat generation state detection unit 8. That is, when the temperature detected by the heat generation state detection means 8 is equal to or higher than a predetermined temperature preset in the control means 600, the amount of power supplied from the auxiliary power supply device 3 to the plurality of drive systems 300 is reduced. I have control.

  The control unit 600 performs control so as to suppress the amount of power supplied from the auxiliary power supply device 3 to the power request unit when the remaining amount of power detected by the operation state detection unit 3a is lower than a preset setting value. To do. That is, the control unit 600 changes the amount of power supplied from the auxiliary power supply device 3 to the drive system 300 and changes the productivity of the printed matter according to the remaining amount of power detected by the operation state detection unit 3a. In addition, each part is controlled. Specifically, when the remaining amount of power detected by the operation state detection unit 3a is lower than a preset set value (including zero), the amount of power supplied from the auxiliary power supply device 3 to the drive system 300 is set. The drive system 300 is controlled so as to suppress and reduce the productivity of printed matter.

The power supply pattern by the heating apparatus 400 having such a configuration will be described in comparison with a conventional power supply pattern.
FIG. 7 is a diagram illustrating the relationship between the operating state of the image forming apparatus and the supplied power, where the vertical axis indicates the supplied power and the horizontal axis indicates time. FIG. 8 shows the temperature of the heating roller 1 (heating member) at the time of continuous paper feeding, power consumption in the drive system 300 serving as the halogen heater 60 and the non-heating unit, and power supplied from each power supply device serving as power supply means. This shows the relationship. As shown in FIG. 7, in the temperature rising section Twu of the heating roller 1, power is supplied from the main power supply 2 to the halogen heater 60 at 1200 W (Wfus_wu), and 300 W is supplied to the drive system 300 serving as another load to form an image. The total power supply to the entire device is 1500W. In this state, the drive system 300 to be driven is a drive system that consumes relatively little power, such as the hard disk device 301 and the engine control unit shown in FIG. For this reason, at the time of start-up shown in FIG. 8, the power consumption in each part can be covered by the single power supply from the main power supply device 1.

  When printing is started from this state and continuous paper feeding is started, a reading driving system such as a lamp shown in FIG. 6, a conveyance driving system 302 (motor), a developing driving system (motor), and writing driving such as a polygon mirror are performed. The system and sensors are also required to be fed, and the power supplied to devices other than the halogen heater 60 exceeds 300 W in the start-up section Twu, and for example, about 500 W is consumed in the drive system 300 other than the halogen heater 60. Necessary. Further, the power required for the halogen heater 60 is about 900 W (Wfus_run) when the fixing system including the heating roller 1 is sufficiently warmed, and is 1400 W (Wall_run) when combined with the required power 500 W of the driving system 300. Printing becomes possible.

  However, in the fixing device 10 of the present application in which the heat capacity of the heating roller 1 is reduced in order to improve start-up performance in a short time, the amount of heat taken away by the paper P is larger than the amount of heat to be heated, and the heating roller 1 is sufficiently heated. The electric power required increases immediately after starting up. For example, in the case where printing is started at 30 seconds from the start of the apparatus and printing is performed at a printing speed of about 65 cpm, power of about 1100 W (Wfus_edlc_run) is required by the halogen heater 60 just after the start-up. That is, in order for the halogen heater 60 to sufficiently maintain the temperature of the heating roller 1 in the fixing temperature range, the required power of the halogen heater 60 is 1100 W (Wfus_edlc_run), and the required power of the driving system 300 other than the fixing is 500 W. If power is to be supplied as it is, a total of 1600 W (Wall_edlc_run) is required, which exceeds the rated power of 1500 W of the main power supply device 1.

  However, high power (1100 W: Wfus_edlc_run) at the halogen heater 60 is not always necessary during continuous paper feeding, but only for a short time of about several minutes immediately after startup. Therefore, as in the present invention, while assisting the power supply to the drive system 300 from the auxiliary power supply 3 for about 200 W, for example, for several minutes (Tedlc), 1100 W (Wfus_edlc_run) is supplied from the main power supply 2 to the halogen heater 60. It becomes possible to do.

  That is, by supplying 200 W from the auxiliary power supply 1 out of the power 500 W consumed by the drive system 300 that is a component other than the fixing device 10 of the image forming apparatus, the power is supplied from the main power supply 1 to the drive system 300. Electric power can be reduced to 300W. Since the rated power of the main power supply device 1 is 1500 W (Wall_wu), the main power supply device 1 can use up to 1500 W−300 W = 1200 W for the halogen heater 60, which is necessary to obtain the temperature necessary for fixing. Thus, there can be enough room to supply 1100 W (Wfus_edlc_run).

  On the other hand, in the conventional heating roller in which the roller base is thick and the heat capacity is not reduced, an auxiliary heater to which power is supplied only from the auxiliary power supply device is provided in the roller, and the auxiliary heater generates heat and the heating roller performs the necessary heating. Was supplemented. For this reason, when the amount of heat taken away by the paper P due to continuous paper passing is large, as shown by the broken line in the temperature characteristic diagram in which the vertical axis in FIG. There is a case where the fixing power is not sufficient only by the power supply, and the temperature is lower than a predetermined minimum temperature (minimum temperature at which fixing is possible). However, in this embodiment, power is supplied from the auxiliary power supply 3 to the drive system 300 of the image forming apparatus that is a system unit. Therefore, as shown by a solid line in FIG. 9, the temperature of the heating roller 1 drops without providing an auxiliary heater. Can be reduced. For this reason, the diameter of the heating roller 1 can be reduced, and the paper P (thick paper) thicker than plain paper when applied to an image forming apparatus with a large number of paper passes per unit time, that is, a high printing speed. Even if the paper is passed, the fixing performance is stable with few fixing defects, and good image quality can be obtained.

  In this embodiment, the remaining power of the auxiliary power supply device 3 is detected by the operation state detection means 3a. When the remaining power is less than a predetermined value (including the remaining amount of zero), the auxiliary power supply is stopped if the image forming operation is in progress. Then, the printing speed (cpm), which is the productivity of the printed matter, is reduced to reduce the productivity, so that the image quality can be ensured. If it can be confirmed that there is no remaining power before printing, the printing speed (cpm) may be reduced from the start of printing to ensure image quality.

  As a form of power supply control by the control means 600, it is not a configuration in which power is supplied from the auxiliary power supply device 3 to the drive system 300 at the time of continuous paper feeding, but from the auxiliary power supply device 3 at the apparatus startup time as shown in FIGS. Power may be supplied to the drive system 300. By doing so, it is possible to shorten the startup time.

  FIG. 10 is a characteristic diagram showing the relationship between power supply to the drive system 300 of the image forming apparatus and replenishment power supply at the time of startup. FIG. 11 shows the temperature of the heating roller 1 (heating member) at the time of power supply and startup, and the halogen heater 60. FIG. 12 is a diagram showing the temperature rise characteristics of the heating roller 1, showing the relationship between the power consumption in the drive system 300 serving as the non-heating unit and the power supplied from each power supply device. In FIG. 10, the vertical axis represents the required electric energy, and the horizontal axis represents time. In FIG. 12, the vertical axis represents the temperature of the heating roller 1, and the horizontal axis represents time.

  That is, in FIGS. 10 and 11, when the required power in the drive system 300 is 300 W and the power used in the fixing system (halogen heater 60) is 1200 W at the start-up time Thu when no power is supplied from the auxiliary power supply device 3, The rated power (Wfus_edlc_wu) of the halogen heater 60 is set to a large value in advance, for example, 1350 W, and the increased power (150 W) is supplied from the auxiliary power supply device 3 to the drive system 300 until a predetermined temperature (fixing temperature) is reached. By supplying power to the power, the power available from the main power supply device 2 for the halogen heater 60 can be increased. For this reason, as shown in FIG. 12, it is shorter to use the main power supply device 2 and the auxiliary power supply device 3 simultaneously and to feed the auxiliary power supply device 3 to the drive system 300 than to use only the main power supply device 2. can do.

  FIG. 13 is a diagram illustrating the relationship between the operating state of the image forming apparatus and the supplied power, where the vertical axis represents the amount of power and the horizontal axis represents time. As a form of power supply control by the control means 600, as indicated by a region A in FIG. 13, the auxiliary power supply device 3 indicated by the region B is driven as a non-heating member in accordance with a decrease in power required by the halogen heater 60. By reducing the power supplied to the system 300, the power supply time from the auxiliary power supply device 3 can be extended.

  In this case, when the temperature of the heating roller 1 is detected by a known temperature detecting means such as a thermistor, and the temperature is sufficiently high and the power supplied to the heating roller 1 can be reduced, the auxiliary power supply device 3 to the drive system 300 is By reducing the feed power and supplying the power from the main power supply device 1, it is possible to reduce the discharge power from the auxiliary power supply device 3 and to reduce the charging time.

  In the example shown in FIG. 13, the power supplied from the auxiliary power supply device 3 is simply reduced. However, even if the auxiliary power supply power is once reduced, the power from the auxiliary power supply device 3 is increased if it becomes necessary again. It is good also as such a control form. Further, the timing of reducing the power from the auxiliary power supply 3 may be determined based not only on the temperature information of the heating roller 1 but on the operation information on the image forming unit side such as the continuous printing time and the number of prints. .

  In the form shown in FIG. 6, the power supply destination of the auxiliary power supply device 3 is switched by the power distribution means 7. However, as shown in FIG. 14, the main power supply device 2 and the auxiliary power supply device 3 are connected to the power distribution means 7. Then, the power from both sides may be appropriately distributed and supplied to the plurality of drive systems 300. In this embodiment, when there is remaining power in the auxiliary power supply 3, power supplied from both the auxiliary power supply 3 and the main power supply 2 is supplied to each drive system 300 of the image forming apparatus, and there is no remaining power. It is only necessary to supply power to the hard disk device 301 and the transport drive system 302 with only power from the main power supply device 2.

  In the embodiment, the present invention is applied to the image forming apparatus, specifically, the fixing device 1 or the fixing device 100 included in the image forming apparatus. Of course, it may be applied appropriately.

1,103 Heating member 2 Main power supply device 3 Auxiliary power supply device (capacitor)
3a Auxiliary power supply state detection means 5 Constant voltage circuit 8 State detection means (operation state detection means)
10, 100 Fixing device 60, 61, 62 Heat generation member 200 Heat generation control means 300 Power request section (image forming section)
301 to 307 Power load device 400 Heating device 500 Current supply means 600 Control means 700 Magnetic flux generation means P Recording material

JP 2003-140484 A JP 2002-044305 A

Claims (4)

An image forming unit for transferring a toner image;
A fixing device for fixing the toner image on a recording material;
A heating member that heats the heating member of the fixing device, and a power supply unit that supplies current to a power request unit other than the heating member;
In the image forming apparatus including a control unit that controls power supply from the power supply unit to the heat generating member and the power request unit.
It said power supply means, and an auxiliary power unit is the main power supply and the power storage device,
A heating state detecting means for detecting the state of the heating member;
The control means supplies power to the heat generating member only from the main power supply device during continuous paper feeding and supplies power to the power request unit including a plurality of drive systems from both the main power supply device and the auxiliary power supply device. A first power supply mode for simultaneously supplying power;
Electric power is supplied from the main power supply device only to the heat generating member and the power request unit including a plurality of drive systems, and the power supplied to the heat generating member is greater than the rated power of the heat generating member by the amount of power required for heat fixing. A second power supply mode to reduce,
The state of the heating member is a temperature state of a heating member heated by the heating member,
The control means switches the first power supply mode to the second power supply mode when the temperature of the heating member detected by the heat generation state detecting means is equal to or higher than a predetermined temperature, and from the auxiliary power supply device, An image forming apparatus that performs control so as to suppress an amount of power supplied to a power request unit. The image forming apparatus according to claim 1.
When the power request unit has a plurality of power load devices,
The image forming apparatus, wherein the control unit supplies power to the plurality of power load devices simultaneously in the first power supply mode. The image forming apparatus according to claim 1.
When the power request unit has a plurality of power load devices,
The image forming apparatus, wherein the control unit supplies power to the plurality of power load devices via a constant voltage circuit heat generation control unit in the first power supply mode. The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus, wherein the auxiliary power supply device comprises a plurality of capacitors.

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