JP5118945B2 - Fixing apparatus, image forming apparatus, and fixing control method for image forming apparatus - Google Patents

Description

The present invention relates to a fixing device mounted on an image forming apparatus such as a copying machine, a printer, or a facsimile, and more particularly to a fixing device , an image forming apparatus, and a fixing control method for the image forming apparatus that complete warm-up at high speed.

In recent years, induction heating type fixing devices used in image forming apparatuses such as electrophotographic copying machines and printers are required to shorten the warm-up time when the power is turned on. For this reason, there is a heating device that uses an induction coil to generate heat from a metal sleeve having a small heat capacity provided on the outer periphery of the heat roller to shorten the warm-up time (for example, Patent Document 1).
JP 2002-295252 A ((0054) to (0057) columns, FIG. 2)

  However, in Patent Document 1, although the warm-up time can be shortened, since the heat capacity of the heat roller is small, it is difficult for the heat roller to maintain a predetermined fixing temperature when images are continuously formed. For this reason, if the temperature of the heat roller decreases during the continuous image formation, it is necessary to wait for the temperature of the heat roller to rise to the fixable temperature, which requires a waiting time. As a result, it takes time to complete the fixing, the speeding up of the image forming speed is impaired, and the fixing performance may be adversely affected.

  For this reason, in the fixing device of the induction heating method, the high-speed performance at the time of warming up is not impaired, and the necessary fixing temperature can be maintained even at the time of continuous image formation, so that a high-quality fixed image can be obtained at high speed. Development of equipment is desired.

Therefore, the present invention solves the above-mentioned problems, and prevents the fixing member from being lowered in temperature during continuous image formation, and does not impair the shortening of the warm-up time. It is an object of the present invention to provide a fixing device , an image forming apparatus, and a fixing control method for the image forming apparatus.

As a means for solving the above problems, the present invention is used in an image forming apparatus whose overall operation is controlled by a first controller, and a heat generating member having a metal conductive layer, and a heat capacity larger than that of the heat generating member. A facing member that pressurizes the member and sandwiches the medium to be fixed between the heating member and conveys the medium in a predetermined direction, an induction current generating coil disposed near the metal conductive layer, and heats the facing member When the startup is completed after starting the startup of the image forming apparatus, power is supplied to the heater even if the startup of the first controller is not completed, and when the startup of the first controller is completed, And a second controller for supplying power to the induction current generating coil .

  According to the present invention, it is possible to shorten the warm-up time, eliminate the shortage of heat capacity during continuous fixing, increase the image forming speed, and improve the fixing performance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. FIG. 1 is a schematic configuration diagram showing an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 includes a scanner unit 6 that reads a document, and a paper feeding unit 3 that supplies sheet paper P as a fixing medium to a printer unit 2 that forms an image. The scanner unit 6 converts image information read from a document supplied from a document feeder 4 provided on the upper surface into an analog signal.

  The printer unit 2 performs image forming stations 18Y, 18M, 18C for each color of yellow (Y), magenta (M), cyan (C), and black (K) along the transfer belt 10a rotated in the direction of the arrow q. The image forming unit 10 is an image forming unit in which 18K is arranged in tandem. Further, the image forming unit 10 includes a laser exposure device 19 that irradiates the photosensitive drums 12Y, 12M, 12C, and 12K of the image forming stations 18Y, 18M, 18C, and 18K of the respective colors with laser beams according to image information. Further, the printer unit 2 includes a fixing device 11 and a paper discharge roller 32, and includes a paper discharge conveyance path 33 that conveys the fixed sheet paper P to the paper discharge unit 5.

  In the yellow (Y) image forming station 18Y of the image forming unit 10, a charger 13Y, a developing device 14Y, a transfer roller 15Y, a cleaner 16Y, and a static eliminator 17Y are arranged around the photosensitive drum 12Y rotating in the direction of arrow r. It has become. The magenta (M), cyan (C), and black (K) image forming stations 18M, 18C, and 18K have the same configuration as the yellow (Y) image forming station 18Y.

  The paper feed unit 3 includes first and second paper feed cassettes 3a and 3b. In the conveyance path 7 of the sheet paper P from the paper feed cassettes 3a and 3b to the image forming unit 10, pickup rollers 7a and 7b for taking out the sheet paper P from the paper feed cassettes 3a and 3b, separation conveyance rollers 7c and 7d, conveyance A roller 7e and a registration roller 8 are provided.

  When the printing operation is started, in the yellow (Y) image forming station 18Y of the printer unit 2, the photosensitive drum 12Y is rotated in the direction of the arrow r and is uniformly charged by the charger 13Y. Next, the photosensitive drum 12Y is irradiated with exposure corresponding to the yellow image information read by the scanner unit 6 by the laser exposure device 19 to form an electrostatic latent image. Thereafter, toner is supplied to the photosensitive drum 12Y by the developing device 14Y, and a yellow (Y) toner image is formed on the photosensitive drum 12Y. This yellow (Y) toner image is transferred to the sheet paper P conveyed in the direction of arrow q on the transfer belt 10a at the position of the transfer roller 15Y. After the transfer of the toner image, the photosensitive drum 12Y is cleaned of residual toner by the cleaner 16Y, the surface of the photosensitive drum 12Y is discharged by the charge eliminator 17Y, and the next printing can be performed.

  In the magenta (M), cyan (C), and black (K) image forming stations 18M, 18C, and 18K, toner images are formed in the same manner as the yellow (Y) image forming station 18Y. The toner images of the respective colors formed by the image forming stations 18M, 18C, and 18K are sequentially transferred to the sheet paper P on which the yellow toner image is formed at the positions of the transfer rollers 15M, 15C, and 15K. The sheet paper P on which the color toner image has been formed in this way is heated and pressed and fixed by the fixing device 11 to complete the print image and discharged to the paper discharge unit 5.

  Next, the fixing device 11 will be described. FIG. 2 is a schematic configuration diagram of the fixing device 11 viewed from the axial direction. The fixing device 11 includes a heat roller 20 that is a heat generating member and a press roller 30 that is a counter member. The heat roller 20 and the press roller 30 each have a diameter of 40 mm, for example. The heat roller 20 is driven in the arrow s direction by a drive motor 36 that is a drive source. The press roller 30 is brought into pressure contact with the heat roller 20 by a pressure mechanism having a spring 44. As a result, a nip 37 having a constant width is formed between the heat roller 20 and the press roller 30. The press roller 30 is rotated in the arrow t direction following the heat roller 20. The heat roller 20 and the press roller 30 constitute a fixing member that sandwiches the sheet paper P at the nip 37 and conveys it in the direction of the paper discharge roller 32.

  The heat roller 20 has a 5 mm thick foam rubber (sponge) 20 b as an elastic layer, a 40 μm thick metal layer 20 c made of nickel (Ni) as a metal conductive layer, and a thickness around the core 20 a. A solid rubber layer 20d having a thickness of 200 μm and a release layer 20e having a thickness of 30 μm are included. The metal layer 20c is not limited to nickel, and may be stainless steel, aluminum, a composite material of stainless steel and aluminum, or the like. Further, the thickness of each layer is not limited. The metal layer 20c, the solid rubber layer 20d, and the release layer 20e are configured so as to be slidable with respect to the foam rubber (sponge) 20b without being bonded to the foam rubber (sponge) 20b. Also good.

  The press roller 30 is configured by covering a hollow cored bar 30a with, for example, a silicon rubber layer 30b and a release layer 30d. The layer pressure of the silicon rubber layer 30b of the press roller 30 is not limited. However, in consideration of thermal conductivity when first and second halogen lamps 38a and 38b described later are provided in the hollow portion of the core metal 30a, the temperature difference between the inside and outside of the silicon rubber layer 30b is reduced. Moreover, it is preferable to make it thin about 0.2 mm-3 mm.

  On the outer periphery of the heat roller 20, there are a peeling claw 54, first and second induced current generating coils 50a and 50b as heat generating means, first to third thermistors 56a, 56b and 56c as temperature sensors, and a first one. And second thermostats 57a and 57b are provided. The peeling claw 54 prevents the sheet paper P after fixing from being wrapped around the heat roller 20. The peeling claw 54 may be either a contact type or a non-contact type. The first and second induced current generating coils 50a and 50b are provided on the outer periphery of the heat roller 20 via a predetermined gap, and cause the metal layer 20c of the heat roller 20 to generate heat.

  The first and third thermistors 56a and 56c detect the surface temperature of the side portion of the heat roller 20 in a non-contact manner and convert it into a voltage. The second thermistor 56b detects the surface temperature at the center of the heat roller 20 in a non-contact manner and converts it into a voltage. As the first to third thermistors 56a, 56b, and 56c that are not in contact with the heat roller 20, for example, thermopile type infrared temperature sensors are used. The first thermostat 57 a detects an abnormality in the surface temperature of the side portion of the heat roller 20. The second thermostat 57 b detects an abnormality in the surface temperature at the center of the heat roller 20. When the first or second thermostat 57a, 57b detects an abnormality, the power supply to the first and second induced current generating coils 50a, 50b is forcibly turned off.

  The first induced current generating coil 50 a generates heat in the central area of the heat roller 20, and the second induced current generating coil 50 b generates heat in areas on both sides of the heat roller 20. The first and second induction current generating coils 50a and 50b are alternately switched and output, and both are set to be adjustable from 200 W to 1100 W, for example. The first and second induced current generating coils 50a and 50b may be capable of outputting simultaneously. In the case of simultaneous output, the output can be changed between the first induced current generating coil 50a and the second induced current generating coil 50b.

  The first and second induced current generating coils 50 a and 50 b are formed by winding a wire around a magnetic core 52 for concentrating the magnetic flux on the heat roller 20. As the wire, for example, a litz wire formed by bundling a plurality of copper wires covered with heat-resistant polyamideimide and insulated from each other is used. By using a litz wire as the wire, the diameter of the wire can be made smaller than the penetration depth of the magnetic field. Thereby, it becomes possible to flow a high-frequency current through the wire effectively. In this embodiment, 19 copper wires having a diameter of 0.5 mm are bundled to form a litz wire.

  When a predetermined high-frequency current is supplied to such a litz wire, the first and second induced current generating coils 50a and 50b generate magnetic flux. Due to this magnetic flux, an eddy current is generated in the metal layer 20c so as to prevent a change in the magnetic field. Joule heat is generated by the eddy current and the resistance value of the metal layer 20c, and the heat roller 20 is instantaneously heated.

  The press roller 30 includes, for example, first and second halogen lamps 38a and 38b, which are heaters, in a hollow metal core 30a. The first halogen lamp 38 a heats the central region of the press roller 30, and the second halogen lamp 38 b heats both sides of the press roller 30. The total power consumption of the first and second halogen lamps 38a and 38b is set to 800 W, for example. Note that an infrared heater may be used as the heater. On the outer periphery of the press roller 30, a peeling claw 61, a first press roller thermistor 62 a that detects the surface temperature of the center portion of the press roller 30, and a second press that detects the surface temperature of the side portion of the press roller 30. A roller thermistor 62b is provided. As the press roller thermistors 62a and 62b, for example, non-contact thermopile type infrared temperature sensors are used.

  Next, a control system 70 for controlling the fixing device 11 will be described with reference to FIG. The control system 70 includes a printer control circuit 80 as a second controller and a system control circuit 81 as a first controller on the secondary board 70b. The printer control circuit 80 controls the operation of the printer unit 2, the paper feed unit 3, the drive motor 36, and the like. The system control circuit 81 controls the operation of the entire image forming system. The printer control circuit 80 can communicate with the system control circuit 81. That is, the printer control circuit 80 receives information on the configuration of the entire image forming system, operation mode, and the like from the system control circuit 81, and outputs information on the printer unit 2 and the paper feeding unit 3 to the system control circuit 81. To do. However, the printer control circuit 80 can control the power supplied to the first and second induced current generating coils 50a and 50b and the first and second halogen lamps 38a and 38b independently of the system control circuit 81. It is said. The system control circuit 81 controls the entire image forming system including other optional devices such as the document feeder 4, finisher, or fax machine.

  On the other hand, the control system 70 includes a fixing control circuit 71 that is a microcomputer that controls the temperature of the heat roller 20 and the press roller 30 on the primary substrate 70a. The fixing control circuit 71 includes an inverter driving circuit 73 that supplies driving power to the first and second induction current generating coils 50a and 50b, and a lamp driving circuit 76 that supplies power to the first and second halogen lamps 38a and 38b. To control. For example, power from the commercial AC power supply 100 is input to the inverter drive circuit 73 and the lamp drive circuit 76 via the breaker 102, the noise filter 103, and the main switch 101.

  The temperature detection results by the first to third thermistors 56a, 56b, 56c and the first and second press roller thermistors 62a, 62b are input to the fixing control circuit 71. The first and second thermostats 57 a and 57 b are arranged in the noise filter 103 and the inverter drive circuit 73 and the lamp drive circuit 76. The first thermostat 57a detects an abnormality in the surface temperature of the side portion of the heat roller 20, and supplies the first and second induced current generating coils 50a and 50b and the first and second halogen lamps 38a and 38b. Forcibly turn off the power supply. The second thermostat 57b detects an abnormality in the surface temperature of the center of the heat roller 20, and supplies the first and second induced current generating coils 50a and 50b to the first and second halogen lamps 38a and 38b. Force power off.

  Next, control when the fixing device 11 is warmed up by the control system 70 will be described. FIG. 4 shows a sequence chart of warm-up control of the fixing device 11 that is performed when the main switch 101 of the image forming apparatus 1 is turned on. When the main switch 101 is turned on to start the image forming apparatus 1, warming up is started, and the heat roller 20 and the press roller 30 reach the fixable temperature.

  First, in order to start the entire image forming system, the main switch 101 is turned on at time t1. Thereby, electric power is supplied from the commercial AC power supply 100 to the primary board 70a and the secondary board 70b of the control system 70. The printer control circuit 80 is started up at time t2, for example, 1-2 seconds after the power supply at t1. However, at this time (time t2), the system control circuit 81 is being activated. Since the system control circuit 81 takes time to decompress the program and start up the OS, it takes about 10 seconds to complete the startup after the main switch 101 is turned on.

  Therefore, at the time t2 when the printer control circuit 80 completes activation, the system control circuit 81 has not completed activation. That is, at the time t2, the overall state of the image forming system is unknown. Therefore, the operation mode of the printer unit 2 is not instructed from the system control circuit 81 to the printer control circuit 80. However, the printer control circuit 80 can control the circuit on the primary substrate 70 a side of the control system 70 of the fixing device 11 independently of the system control circuit 81. That is, the printer control circuit 80 can perform temperature control or error detection of the heat roller 20 or the press roller 30 by the fixing control circuit 71 without being instructed by the system control circuit 81.

  Therefore, the printer control circuit 80 can supply power to the halogen lamps 38a and 38b and the induction current generating coils 50a and 50b without waiting for the system control circuit 81 to complete the startup. On the other hand, in the fixing device 11, the press roller 30 having a large heat capacity requires a longer time to reach the fixable temperature than the heat roller 20 having a very small heat capacity. Therefore, in consideration of both the heat roller 20 and the press roller 30, in order to shorten the time from when the fixing device 11 completes the warm-up until the power is turned on, compared with the heat roller 20, the press roller 30 It is preferable to perform the heating in advance.

  Therefore, when the printer control circuit 80 completes the activation at time t2, the activation of the system control circuit 81 has not been completed, and the printer control circuit 80 is not instructed about the operation mode of the printer unit 2, but first. The lamp driving circuit 76 is controlled via the fixing control circuit 71 so as to supply power to the first and second halogen lamps 38a and 38b. At this time, the fixing device 11 can use the remaining power obtained by subtracting the startup power of the printer control circuit 80 and the system control circuit 81 from the total amount of power that can be used in the entire image forming system. That is, the amount of electric power that can be supplied to both the first and second halogen lamps 38a and 38b on the press roller 30 side remains in the entire image forming system. Accordingly, the lamp control circuit 76 supplies necessary power to both the first and second halogen lamps 38a and 38b and controls to turn on both the first and second halogen lamps 38a and 38b. . As a result, the first and second halogen lamps 38a and 38b are turned on at time t3. That is, the press roller 30 is heated before the system control circuit 81 instructs the printer control circuit 80 to enter the warm-up mode.

  In this way, when the press roller 30 is heated by the first and second halogen lamps 38a and 38b, for example, when about 10 seconds elapse from the turn on of the main switch 101, the system control circuit is reached. 81 completes activation. As a result, the system control circuit 81 looks at the configuration of the entire image forming system or the status of the entire image forming system, such as whether options are down. If the image forming system is normal, the printer control circuit 80 is instructed to warm up.

  When the warm-up mode is instructed by the system control circuit 81, the printer control circuit 80 instructs the drive motor 36 to rotate the heat roller 20, and the first and second inverter driving circuits 73 via the fixing control circuit 71 Control is performed so that power is supplied to the second induction current generating coils 50a and 50b. As a result, the heat roller 20 starts to generate heat.

  However, since the total power that can be supplied from the commercial AC power supply 100 to the entire image forming system is limited, the first and second halogen lamps 38a and 38b and the first and second induced currents are used for the warm-up mode. The power supplied to both the generating coils 50a and 50b is limited. Therefore, the fixing control circuit 71 is connected to the first and second halogen lamps 38a and 38b and the first and second halogen lamps 38a and 38b so as to realize warming-up at a higher speed in the range of power usable for temperature control of the fixing device 11. The amount of power supplied to the second induction current generating coils 50a and 50b is optimally distributed and feedback controlled.

  When an error or the like occurs in the image forming system when the activation of the system control circuit 81 is completed (t4), the system control circuit 81 immediately supplies power to the fixing device 11 to the printer control circuit 80. Instruct to shut off.

  On the other hand, the temperature detection results of the first to third thermistors 56a, 56b, 56c and the first and second press roller thermistors 62a, 62b are input to the fixing control circuit 71 in accordance with the instruction of the warm-up mode. Using this temperature detection result, the inverter drive circuit 73 and the lamp drive circuit 76 use the first and second halogen lamps 38a and 38b so that the heat roller 20 and the press roller 30 reach a predetermined fixable temperature. The power supplied to the first and second induced current generating coils 50a and 50b is feedback-controlled.

  At the time t4 when the activation of the system control circuit 81 is completed, the press roller 30 is already heated by the first and second halogen lamps 38a and 38b during the time t3 to t4. Therefore, after that, the heat roller 20 and the press roller 30 are operated at high speed by feedback control of the electric energy to the first and second halogen lamps 38a and 38b and the first and second induction current generating coils 50a and 50b. Then, the temperature reaches a predetermined fixable temperature and enters a standby mode (a state in which printing is possible immediately when a print instruction is issued).

  After entering the standby mode at time t5, the fixing control circuit 71 sets the first and second induced current generating coils 50a and 50b to a low level, for example, so that the heat roller 20 and the press roller 30 maintain the fixing possible temperature. Electric power is alternately supplied, and the first and second halogen lamps 38a and 38b are controlled to be turned on / off.

  In this way, when the print mode is instructed from the system control circuit 81 while in the standby mode, the printer control circuit 80 performs print control. Accordingly, the fixing control circuit 71 performs feedback control of the heat roller 20 and the press roller 30 in the print mode. That is, the fixing control circuit 71 supplies power to the first induction current generating coil 50a and turns on / off the first halogen lamp 38a, for example, when the sheet P size is JIS standard A / 4 size. Control.

  After the print mode is completed, after the predetermined time has elapsed after the standby mode state is maintained, the system control circuit 81 sends, for example, a printer control circuit 80 to the sleep mode (first and second guidance) in order to save power consumption. When the power supply to the current generating coils 50a and 50b and the first and second halogen lamps 38a and 38b is cut off and a print instruction is issued, the heat roller 20 and the press roller 30 are immediately raised to a fixing temperature. To raise). When the sleep mode is instructed from the system control circuit 81 to the printer control circuit 80 at time t6, the inverter drive circuit 73 and the lamp drive circuit 76 are stopped, and the first and second induced current generating coils 50a and 50b are stopped. Power supply and the first and second halogen lamps 38a, 38b are turned off. Thereafter, the printer control circuit 80 is also turned off at time t7. However, the system control circuit 81 holds the activation while the entire image forming system is in the sleep mode.

  Therefore, when there is a print instruction during the sleep mode, the system control circuit 81 instructs the entire image forming system to cancel the sleep mode, for example, at time t8. As a result, the printer control circuit 80 completes startup immediately from the off state (t9), and energizes the inverter drive circuit 73 and the lamp drive circuit 76 simultaneously with the rotation of the drive motor 36 (t10). As a result, the temperature of the heat roller 20 and the press roller 30 is controlled so as to immediately reach the fixable temperature.

  According to the fixing device 11 of this embodiment, in the heat roller 20, the thickness of the metal conductive layer 20c is reduced, and the heat capacity of the heat roller 20 is extremely reduced. As a result, at the time of warming up, the heat roller 20 can reach a desired fixing temperature in a short time, and the warming up speed and thus the fixing speed are increased. At the same time, the press roller 30 having a large heat capacity is heated by the first and second halogen lamps 38a and 38b. As a result, the press roller 30 can compensate for a shortage of heat capacity on the heat roller 20 side during continuous fixing, and can prevent the temperature of the heat roller 20 from decreasing during continuous fixing. Therefore, when the temperature of the heat roller 20 decreases during continuous fixing, there is no need to wait for the heat roller 20 to return to the fixable temperature again. As a result, it is possible to prevent the fixing speed from being lowered even during continuous fixing.

  In addition, according to the fixing device 11 of this embodiment, even if the activation of the system control circuit 81 is not completed after the power of the image forming apparatus 1 is turned on, if the printer control circuit 80 is started up, Electric power is supplied to the second halogen lamps 38a and 38b first. That is, the printer control circuit 80 instructs power supply to the first and second halogen lamps 38a and 38b before the system control circuit 81 instructs warming up. Thereby, the press roller 30 having a large heat capacity is started to be heated before the warm-up instruction is given by the system control circuit 81, and is already heated at the time t4 when the warm-up is instructed by the system control circuit 81. As a result, although the press roller 30 has a larger heat capacity than the heat roller 20, it is possible to suppress a delay in the rise after the warm-up instruction by the system control circuit 81, and to shorten the warm-up time of the fixing device 11. .

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, the structure of the fixing device is not limited, and the heat generating member or the opposing member may be belt-shaped. In addition, the time from the start of the first controller or the second controller to the completion of the start is also arbitrary, and the range of the amount of power of the heater or the amount of power that can be supplied to the induction current generating coil is also arbitrary as required. is there.

  Further, the operation control by the first controller is not limited. For example, in the sequence chart of FIG. 4 of the above embodiment, the system control circuit 81 instructs the sleep mode at time t6, but the present invention is not limited to this. For example, after a predetermined time elapses in the standby mode after the print mode is finished, the system control circuit 81 first maintains the preheating mode (the fixing member at a predetermined preheating temperature lower than the fixing possible temperature at time t6, and a print instruction is issued. If there is, it may be instructed to immediately raise the fixing member to the fixing temperature, and then the sleep mode may be designated.

  Further, the sequence for warming up the fixing member to the fixing temperature can be changed. For example, the modification shown in FIG. 5 may be used. In this modification, the first and second halogen lamps 38a and 38b are turned on at the time t3 after the start of the printer control circuit 80 is completed at the time t2, and at the same time, the drive motor 36 is rotated to In addition, power is supplied to the second induction current generating coils 50a and 50b. As a result, before the system control circuit 81 completes activation and before instructing the warm-up mode, both the heat roller 20 and the press roller 30 start to be heated. However, since the total amount of electric power that can be supplied from the commercial AC power supply 100 to the entire image forming system is limited, the first and second halogen lamps 38a and 38b and the first and second induced currents at time t3. The amount of power supplied to each of the generating coils 50a and 50b is limited.

  That is, at time t3 of this modification, the amount of power that can be used for temperature control of the fixing device 11 is determined from the total amount of power that can be used in the entire image forming system by the startup power of the printer control circuit 80 and the system control circuit 81 Furthermore, the remaining electric power is obtained after at least the electric power supplied to the drive motor 36 is subtracted. Then, the remaining electric power is allocated to the first and second halogen lamps 38a and 38b and the first and second induced current generating coils 50a and 50b. Therefore, in this modification, the amount of electric power that can be supplied to the first and second halogen lamps 38a and 38b at time t3 is reduced compared to the previous embodiment. As a result, there is a possibility that the heating efficiency when the press roller 30 having a large heat capacity is heated before the warm-up mode is instructed by the system control circuit 81 is somewhat reduced.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 1 is a schematic configuration diagram of a fixing device according to an embodiment of the present invention viewed from an axial direction. FIG. 2 is a schematic block diagram illustrating a control system of the fixing device according to the embodiment of the present invention. 6 is a sequence chart showing warm-up control of the fixing device according to the embodiment of the present invention. 7 is a sequence chart showing warm-up control of a fixing device according to a modification of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Printer part 10 ... Image forming unit 10a ... Transfer belt 11 ... Fixing device 20 ... Heat roller 20c ... Metal conductive layer 30 ... Press roller 36 ... Fixing motor 38a, 38b ... 1st and 2nd halogen Lamp 44 ... Spring 50a, 50b ... First and second induction heating coils 56a, 56b, 56c ... First to third thermistors 57a, 57b ... First and second thermostats 62a, 62b ... First and second Press roller thermistor 70 ... control system 70a ... primary board 70b ... secondary board 71 ... fixing control circuit 73 ... inverter drive circuit 76 ... lamp drive circuit 80 ... printer control circuit 81 ... system control circuit

Claims (10)

A heating member used in an image forming apparatus whose overall operation is controlled by a first controller and having a metal conductive layer ;
A facing member that has a heat capacity larger than that of the heat generating member and pressurizes and contacts the heat generating member and sandwiches a medium to be fixed between the heat generating member and conveys the medium in a predetermined direction;
An induction current generating coil disposed near the metal conductive layer;
A heater for heating the facing member;
When the startup is completed after the start of the image forming apparatus, the heater is supplied with power even if the startup of the first controller is not completed, and when the startup of the first controller is completed, the induction current generating coil And a second controller for supplying power to the fixing device. The fixing device according to claim 1, further comprising a drive source for rotating the heat generating member. 3. The fixing according to claim 2, wherein when the image forming apparatus returns from the sleep mode, power supply to the heater, drive start of the drive source, and power supply to the induction current generating coil are simultaneously performed. apparatus. The microcomputer further includes a temperature control dedicated microcomputer for controlling power supplied to the induction current generating coil and the heater, and the second controller supplies power supplied to the induction current generating coil and the heater via the temperature control dedicated microcomputer. The fixing device according to claim 1 , wherein the fixing device is controlled. The heat generating member comprises a rotating body formed by covering a surface of an elastic body layer with the metal conductive layer, and the induction current generating coil is disposed around the rotating body. Item 4. The fixing device according to any one of Items 3 to 3 . An image forming unit that forms an image on a fixing medium;
A first controller that controls the operation of the entire image forming apparatus;
A heat generating member having a metal conductive layer;
A counter member that has a heat capacity larger than that of the heat generating member and pressurizes and contacts the heat generating member and sandwiches the fixing medium between the heat generating member and conveys it in a predetermined direction;
An induction current generating coil disposed near the metal conductive layer;
A heater for heating the facing member;
When the startup is completed after the start of the image forming apparatus, the heater is supplied with power even if the startup of the first controller is not completed, and when the startup of the first controller is completed, the induction current generating coil And a second controller for supplying power to the image forming apparatus. Starting the image forming apparatus; and
Starting the second controller after starting the image forming apparatus ;
Supplying power to a heater that heats the opposing member even if activation of the first controller that controls the overall operation of the image forming apparatus is not completed ;
A step of supplying electric power to an induction current generating coil for generating heat in a metal conductive layer of a heat generating member having a heat capacity smaller than that of the facing member and capable of being in pressure contact with the facing member when the activation of the first controller is completed. A fixing control method for an image forming apparatus. Wherein After first completing the activation of the controller, the fixing method of controlling an image forming apparatus according to claim 7, wherein the starting rotating the heating member. When the image forming apparatus returns from the sleep mode after the start of the image forming apparatus, power is supplied to the heater, and at the same time, rotation of the heat generating member and power supply to the induction current generating coil are performed. fixing control method of an image forming apparatus according to claim 7 or claim 8, characterized in that performed simultaneously. The induced current generating power supply to the coil and the heater, the fixing control method for an image forming apparatus according to any one of claims 7 to 9, characterized in that via the temperature control dedicated microcontroller.

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