JP5066904B2 - Electromagnetic induction heating type fixing device and magnetic flux generation unit - Google Patents

Description

  The present invention relates to an electromagnetic induction heating type fixing device that heat-fixes a toner image on a recording medium. More specifically, the present invention relates to a fixing device in which a degaussing coil is mounted on an exciting coil and the temperature of the heating rotating body is adjusted in the longitudinal direction.

  In recent years, electromagnetic induction heating type fixing devices have been proposed from the viewpoint of reducing power consumption and starting time. The electromagnetic induction heating type fixing device has a magnetic flux generating section provided with an exciting coil and the like, and promotes heat generation of the electromagnetic induction heat generating layer in the fixing roller by forming a magnetic field by the magnetic flux generating section. The electromagnetic induction heating type fixing device has a feature that the heat generating layer can be directly heated, and can have a structure in which the heat capacity of the fixing member is smaller than that of the halogen heater. As a result, high thermal efficiency and high-speed heating can be achieved.

  Further, in the fixing device, in order to form an image on various sizes of paper, the fixing roller is partially heated in accordance with the size of the paper. In the case of the electromagnetic induction heating type fixing device, the fixing roller is divided into a plurality of areas in the axial direction, the excitation coils are juxtaposed in each area, and the heating area of the fixing roller is adjusted by turning on / off the power supply to each excitation coil. (For example, Patent Document 1) is disclosed.

  In such a fixing device having a magnetic flux generation unit capable of adjusting the heating region, a plurality of coils are arranged adjacent to each other in the axial direction. Therefore, insulation between adjacent coils becomes a problem. For example, in patent document 1, the insulation member integrally formed with the bobbin is arrange | positioned between adjacent coils, and the insulation between coils is ensured. However, like the fixing device of Patent Document 1, when a plurality of coils are arranged in the axial direction of the fixing roller, a region for arranging an insulating member between the coils, that is, a region for ensuring insulation between the coils is provided. Must be provided. As a result, heating unevenness is generated in the axial direction of the fixing roller 1.

Therefore, as a fixing device that suppresses uneven heating, a demagnetizing coil that forms a magnetic field opposite to the exciting coil is mounted on the exciting coil, and the heating region of the fixing roller is adjusted by the demagnetizing effect of the demagnetizing coil (for example, Patent Document 2) is disclosed. In such a fixing device in which a plurality of coils are stacked, insulation between the coils is achieved by sandwiching a flexible insulating member such as insulating paper between the coils.
Japanese Patent Laid-Open No. 2001-319763 JP 2001-34097 A

  However, the electromagnetic induction heating type fixing device has the following problems. That is, in a fixing device in which a plurality of coils are stacked, a rib for positioning the coil is provided in the bobbin, and the rib is shared by the plurality of coils. Therefore, as shown in FIG. 15, the insulating member 900 sandwiched between the coils is provided with an inner hole 901 through which the rib passes. However, as shown in FIG. 16, when the coils 931 and 934 are stacked with the insulating member 900 interposed therebetween, the creeping surface between the coil 931 positioned on the lower side and the coil 934 positioned on the upper side around the inner hole through which the rib 937 passes. The distance becomes shorter. Therefore, good insulation cannot be obtained. On the other hand, it is conceivable to close the inner hole 901 in order to ensure insulation, but if the inner hole 901 is blocked, the coils 931 and 934 cannot be positioned by the rib 937. Therefore, the positioning accuracy of the coils 931 and 934 is impaired.

  The present invention has been made to solve the problems of the conventional electromagnetic induction heating type fixing device. That is, an object of the present invention is to provide an electromagnetic induction heating type fixing device that suppresses poor insulation between stacked coils without impairing the positioning accuracy of the coils.

A fixing device made for the purpose of solving this problem is a heating rotator provided with a heat generating layer that generates electromagnetic induction heat, and is positioned on the outer peripheral side of the heating rotator, and is attached to the heating rotator along the axial direction of the heating rotator. An electromagnetic induction heating type fixing device that is disposed opposite to each other and has a magnetic flux generation unit that generates a magnetic flux by power feeding. The magnetic flux generation unit is provided on a bobbin that faces the heating rotator, and the bobbin. A fixed support column, a first coil mounted on the bobbin and wound on the support column, a second coil mounted on the first coil and wound on the support column, and a first coil And the second coil, and an insulating member provided with an inner hole penetrating the support column. The insulating member is arranged on the first coil side or the second coil side on the inner peripheral part forming the inner hole. It is characterized by having a collar part protruding to the surface.

  That is, the fixing device according to the present invention is of an electromagnetic induction heating type, and a magnetic flux generator is disposed opposite to the outer peripheral side of the heating rotator along the axial direction thereof. The heating rotator may be a roller member or a belt member. In the fixing device of the present invention, a magnetic field is generated between the magnetic flux generator and the heating rotator by supplying power to the magnetic flux generator. An eddy current is generated in the heat generating layer (electromagnetic induction heat generating layer) of the heating rotator by the generation of the magnetic field, and the heat generating layer is heated.

  In addition, the first coil and the second coil are stacked on the magnetic flux generator of the fixing device. These coils function as, for example, an exciting coil that generates magnetic flux by feeding and forms a magnetic field with the heating rotator, or a degaussing coil that extinguishes part of the magnetic field. These coils are wound around a support column fixedly arranged in the magnetic flux generator. That is, the support column functions as a common positioning member for the first coil and the second coil. Therefore, the positioning accuracy of each coil is high.

  Further, an insulating member provided with an inner hole through which the support column can be passed is sandwiched between the first coil and the second coil. Thereby, the insulation between the first coil and the second coil is achieved. Further, the insulating member is provided with a flange portion protruding toward one of the coils on the inner peripheral portion forming the inner hole. By covering the side surface of one coil bundle with the flange, a creeping distance sufficient for insulation is secured between the two coils. This suppresses insulation failure between the coils around the inner hole.

  Moreover, it is better that the height of the flange portion of the insulating member is higher than the height of the coil bundle located on the protruding side. That is, by making the height of the collar portion higher than the height of the coil covering, the side surface of one coil bundle is covered, and the creeping distance between the two coils is increased. Therefore, the insulation between both coils is improved.

  According to the present invention, an electromagnetic induction heating type fixing device in which an insulation failure between stacked coils is suppressed without impairing the coil positioning accuracy is realized.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to an electromagnetic induction heating type fixing device provided in an electrophotographic printer.

  The image forming apparatus according to the present embodiment is an electrophotographic laser printer. As shown in FIG. 1, a laser oscillator 102, a polygon mirror 103, and a reflecting mirror 104 are arranged in an optical system, and a photoconductor is provided in an image processing unit. A drum 101, a charging device 105, a developing device 106, a transfer device 107, and a cleaning blade 108 are arranged. In addition, a paper feed roller 109, a paper discharge roller 115, a paper feed sensor 110, a paper discharge sensor 114, a fixing device 100, and the like are disposed in the transport unit.

  Next, the operation of the laser printer configured as described above will be briefly described. The photosensitive drum 101 rotates in the direction of the arrow in FIG. 1, and the surface is uniformly charged by the charger 105. Further, the laser light is modulated and emitted from the laser oscillator 102 based on the image signal. This laser beam is scanned in the main scanning direction by the polygon mirror 103, reflected by the reflection mirror 104, and incident on the photosensitive drum 101. Thereby, an electrostatic latent image is formed on the photosensitive drum 101. This electrostatic latent image is developed by the developing device 106 to become a toner image. The toner image is transferred onto the recording paper P fed by the paper feed roller 109 by a transfer device 107 disposed opposite to the photosensitive drum 101. Thereafter, the recording paper P onto which the toner image has been transferred is heated in the fixing device 100, and the toner image is melted and fixed on the recording paper P by the heat. After the image is fixed, the recording paper P is discharged out of the apparatus by a paper discharge roller 115. With the above operation, printing for one sheet is performed.

  Next, the configuration of the fixing device 100 of this embodiment will be described. 2 is a schematic configuration diagram of the fixing device 100 as viewed from the axial direction (front), and FIG. 3 is a schematic configuration diagram of the fixing device 100 as viewed from the side surface upstream in the sheet passing direction. The fixing device 100 is an electromagnetic induction heating type fixing device, and includes a fixing roller 1, a pressure roller 2, a magnetic flux generation unit 3, temperature sensors 41 and 42, a current-carrying shielding unit 7, and a separation claw 8. Have. P indicates a sheet.

  The fixing roller 1 and the pressure roller 2 are arranged in parallel in the axial direction of the fixing roller 1 (hereinafter abbreviated as “axial direction”). The pressure roller 2 is rotationally driven at a predetermined speed by a drive mechanism such as a motor. The pressure roller 2 is biased toward the fixing roller 1 by a biasing member such as a spring, and forms a nip portion with the fixing roller 1. Further, the fixing roller 1 is provided so as to be driven to rotate by the rotation of the fixing roller 1 by a pressure frictional force with the pressure roller 2. Note that the fixing roller 1 may be driven to rotate, and the pressure roller 2 may be driven to rotate.

  In the fixing roller 1, a heat insulating layer, an electromagnetic induction heat generating layer, an elastic layer, and a release layer are sequentially laminated on a cored bar. The roller hardness is set, for example, in the range of 30 to 90 degrees as Asker C hardness. In the pressure roller 2, a silicon sponge layer and a release layer are sequentially stacked on a cored bar. The pressure roller 2 is pressed against the fixing roller 1 with a load of 300 N to 500 N, and the width of the nip portion is in the range of 5 mm to 15 mm. The load may be changed depending on the type of recording paper.

  The electromagnetic induction heat generating layer of the fixing roller 1 is a layer that generates Joule heat by excitation by the magnetic flux generator 3, and has a high magnetic permeability and an appropriate resistivity. Moreover, it is possible to use a non-magnetic material or a thin film of a conductive material such as metal. Further, a resin in which exothermic particles are mixed may be used. An eddy current flows through the electromagnetic induction heat generating layer by excitation by a magnetic flux generator 3 described later. Since the electromagnetic induction heat generating layer has a small heat capacity and is in contact with the heat insulating layer located on the core metal side, the elastic layer or the release layer located on the surface layer side of the fixing roller 1 is rapidly heated.

  In the pressure roller 2, a silicon sponge layer and a release layer are sequentially laminated on a cored bar. The pressure roller 2 is pressed against the fixing roller 1 with a load of 300 N to 500 N, and the width of the nip portion is in the range of 5 mm to 15 mm. The load may be changed depending on the type of recording paper.

  The magnetic flux generator 3 includes an exciting coil 31, a magnetic core 32, a coil bobbin 33, and degaussing coils 34 and 35. The magnetic flux generator 3 generates a magnetic flux by supplying power to the exciting coil 31 and forms a magnetic field in a region facing the fixing roller 1. As shown in FIG. 4, a high frequency inverter 5 (excitation circuit) is connected to the excitation coil 31, and the high frequency inverter 5 is controlled by a control circuit 6.

  The magnetic flux generator 3 is disposed at both ends of the exciting coil 31 and reduces the magnetic field of the exciting coil 31 by the demagnetizing effect of the demagnetizing coils 34 and 35 that forms a magnetic field opposite to the exciting coil 31. Adjust the heating range. Details of the magnetic flux generator 3 will be described later.

  The temperature sensors 41 and 42 are for detecting the surface temperature of the fixing roller 1 and are arranged on the outer periphery of the fixing roller 1. Moreover, the temperature sensor 41 is arrange | positioned in the approximate center on the axial direction. The temperature sensor 41 only needs to have a position in the axial direction within a range in which the minimum width paper defined by the fixing device 100 is passed. Moreover, the temperature sensor 42 is arrange | positioned at the edge part on an axial direction. In addition, the temperature sensor 42 should just be in the range where the position on an axial direction has the demagnetizing coil 34 arrange | positioned. As the temperature sensors 41 and 42, for example, a thermistor can be used. Each detection signal of the temperature sensors 41 and 42 is input to the control circuit 6.

  The control circuit 6 controls the high frequency inverter 5 and the switches 51 and 52 (that is, controls the magnetic field). The control circuit 6 controls the high-frequency inverter 5 based on the paper size information and the detection signals of the temperature sensors 41 and 42 to increase or decrease the power supply to the excitation coil 31. That is, automatic control is performed so that the surface temperature of the fixing roller 1 is constant. Further, the heat generation area of the fixing roller 1 is adjusted by controlling the switches 51 and 52.

  The energization shielding unit 7 shields the circuit at a temperature equal to or higher than a predetermined value and cuts off the current to the exciting coil 31, and is disposed around the fixing roller 1. The energization shielding unit 7 can stop the operation of heat generation when the surface temperature of the fixing roller 1 exceeds a predetermined value, and the deterioration of the fixing roller 1 due to excessive temperature rise is suppressed. For example, a thermostat or a thermal fuse can be used as the energization shielding unit 7.

  Next, a fixing operation in the fixing device 100 of this embodiment will be described. First, as a warm-up operation, the pressure roller 2 is rotationally driven, and the fixing roller 1 is also rotated in accordance with this. A predetermined magnetic field is formed by applying an alternating current to the exciting coil 31 of the magnetic flux generator 3. Due to the action of the magnetic flux generated by the magnetic flux generator 3, the electromagnetic induction heat generating layer of the fixing roller 1 generates heat at a position facing the magnetic flux generator 3. Then, the surface temperature of the fixing roller 1 is automatically controlled so as to become a predetermined temperature. Since the electromagnetic induction heating layer has a small heat capacity and is insulated and held by the heat insulating layer, the elastic layer or the release layer located on the surface layer side of the fixing roller 1 is rapidly heated. In other words, the surface of the fixing roller 1 quickly reaches the fixable temperature.

  After the warm-up operation is completed, the recording paper P carrying an unfixed toner image is conveyed to the nip portion between the fixing roller 1 and the pressure roller 2 (see FIG. 2). The control circuit 6 controls the magnetic field by turning on and off the circuits of the degaussing coils 34 and 35 based on the information of the temperature sensor 42. Thereby, a desired range of the fixing roller 1 is heated. When the recording paper P reaches the fixing device 100, the toner image on the recording paper P faces the fixing roller 1. The recording paper P introduced into the nip portion is nipped and conveyed through the nip portion and heated by heat from the fixing roller 1. As a result, the unfixed toner image is melted and fixed on the recording paper P.

  The recording paper P after the fixing process at the nip portion is separated from the fixing roller 1 and carried out. At that time, even if the recording paper P is stuck on the surface of the fixing roller 1 by the separation claw 8 arranged in contact with the surface of the fixing roller 1, it is forcibly separated. As a result, jamming in the fixing device 100 is prevented.

  Next, details of the magnetic flux generator 3 will be described. FIG. 5 is a perspective view of the fixing device 100 as viewed from the magnetic flux generation unit 3 side, and FIG. 6 is a perspective perspective view of the fixing device 100 seen through the cover 330 in FIG. As shown in FIG. 5, the magnetic flux generator 3 is located outside the fixing roller 1 and is disposed along the longitudinal direction so as to face the fixing roller 1.

  The exciting coil 31 has a structure in which a conducting wire is wound in the axial direction. Further, as shown in FIG. 4, the excitation coil 31 is connected to the high frequency inverter 5 and is supplied with high frequency power of 100 W to 2000 W. For this reason, a thin wire bundled within a range of several tens to several hundred wires is used as a litz wire. In consideration of the case where heat is transferred to the winding, it is covered with heat-resistant resin.

  Further, an alternating current of 10 kHz to 100 kHz is applied to the excitation coil 31 by the high frequency inverter 5. The magnetic flux induced by the alternating current passes through the ferrite core 32 and further passes through the electromagnetic induction heating layer of the fixing roller 1. That is, a magnetic field is formed between the fixing roller 1 and the magnetic flux generator 3. Then, an eddy current flows through the electromagnetic induction heating layer, so that the electromagnetic induction heating layer itself generates Joule heat. As a result, the fixing roller 1 is heated.

  The magnetic core 32 has a substantially U-shaped cross section, and is disposed so as to straddle the exciting coil 31 and the degaussing coils 34 and 35 as shown in FIG. 3 or FIG. Are arranged at predetermined intervals. Further, the magnetic core 32 may be formed in a substantially E shape by providing a central portion protruding toward the fixing roller in order to increase the heat generation efficiency. As the material of the magnetic core 32, a material having high permeability and low loss (for example, ferrite) is used. In the case of an alloy such as permalloy, the eddy current loss in the core increases in the high frequency region, so a laminated structure is preferable.

  The magnetic core 32 has both functions of increasing the efficiency of the magnetic circuit and magnetic shielding. If there is a means capable of sufficient magnetic shielding, an air core (no core) may be used. In addition, if a core material made of a resin material mixed with magnetic powder is used, the design flexibility of the shape is increased.

  Further, as shown in FIG. 7, various ribs are provided inside the coil bobbin 33 for positioning the coils. Specifically, ribs 36 are provided at both ends in the longitudinal direction. Ribs 37 and 37 are provided on the inner side in the longitudinal direction of the magnetic flux generation unit 3 than the ribs 36. Further, on the inner side, that is, in the central portion, a pair of ribs 38, 38 arranged in parallel in the longitudinal direction is provided.

  That is, the exciting coil 31 is wound over the entire longitudinal direction of the magnetic flux generator 3 via the ribs 36, 37, 38, 37, 36. On the other hand, the degaussing coil 34 is wound around the ribs 36 and 37, and the winding portions exist at both ends in the longitudinal direction of the magnetic flux generation unit 3. Further, the demagnetizing coil 35 is wound around the rib 36, and the winding portion exists at both ends.

  As shown in FIG. 3, each of the degaussing coils 34 and 35 has a structure in which a conducting wire is wound around both ends in the longitudinal direction. Since the demagnetizing coils 34 and 35 have different axial widths, the range in which magnetic flux is formed, that is, the range in which the magnetic field formed by the exciting coil 31 is extinguished is different. Specifically, the degaussing coil 34 is disposed in the region of both ends of the exciting coil 31. The demagnetizing coil 35 is located in the axial direction in a region where the demagnetizing coil 34 is disposed, and the axial width is narrower than the demagnetizing coil 34 and is disposed on the end side of the fixing roller 1.

  Further, the degaussing coil 34 forms a closed circuit through the switch 51 as shown in FIG. The degaussing coil 35 also forms a closed circuit via the switch 52. The switches 51 and 52 are appropriately turned on and off by the control circuit 6. When the switch 51 is turned on, the demagnetizing coil 34 generates an induced back electromotive force due to the magnetic flux from the exciting coil 31, forms a magnetic field opposite to the exciting coil 31, and exhibits a demagnetizing effect. The demagnetizing coil 35 also exhibits a demagnetizing effect when the switch 52 is turned on. Thereby, the generation range of Joule heat in the predetermined region is suppressed.

  Next, the loading state of each coil in the magnetic flux generator 3 will be described. As shown in FIG. 8, the magnetic flux generator 3 of this embodiment has the exciting coil 31 as the lowermost layer, the demagnetizing coil 34 is overlaid as the upper layer of the exciting coil 31, and the degaussing coil 35 is overlaid as the upper layer of the demagnetizing coil 34. It has a three-layer structure.

  Insulating paper 91 is interposed between the degaussing coil 34 and the exciting coil 31 to insulate them. As shown in FIG. 9, the outer shape of the insulating paper 91 is substantially elliptical, and the outer shape is larger than the outer shape of the coil bundle of the degaussing coil 34. Further, an inner hole 911 through which the ribs 36 and 37 can pass is provided in the central portion of the insulating paper 91. Therefore, the insulating paper 91 can be sandwiched between the exciting coil 31 and the degaussing coil 34. Further, the insulating paper 91 has flexibility, and is arranged so as to be curved so as to cover the end of the exciting coil 31 as shown in FIG.

  Further, the inner peripheral portion forming the inner hole 911 of the insulating paper 91 is configured by two parallel straight portions 911A and a curved portion 911B connecting the straight portions 911A and 911A, and the straight portion 911A includes the demagnetizing coil 34 side. A flange portion 912 that is bent into a protrusion shape is provided. As shown in FIG. 11, the flange portion 912 is disposed between the ribs 36 and 37 and the degaussing coil 34. That is, as shown in FIG. 12, the flange portion 912 covers a part of the side surface on the inner hole side of the coil bundle of the degaussing coil 34. Therefore, the creeping distance between the degaussing coil 34 and the exciting coil 31 becomes long. Therefore, good insulation can be obtained between both coils.

  Insulating paper 92 is interposed between the degaussing coils 34 and 35 to insulate them. As shown in FIG. 13, the insulating paper 92 has a substantially elliptical outer shape, and the outer shape is larger than the outer shape of the coil bundle of the degaussing coil 35. Further, an inner hole 921 through which the rib 36 can penetrate is provided in the central portion of the insulating paper 92. Therefore, the insulating paper 92 can be sandwiched between the degaussing coils 34 and 35. Further, the insulating paper 92 has flexibility, and is arranged so as to be curved so as to cover the end of the demagnetizing coil 34.

  Further, the inner peripheral surface forming the inner hole 921 of the insulating paper 92 is constituted by two parallel straight portions 921A and a curved portion 921B connecting the straight portions 921A and 921A. The straight portion 921A includes the insulating paper 91 and Similarly, a flange portion 922 that is bent toward the degaussing coil 35 and has a protruding shape is provided. As shown in FIG. 8, the flange portion 922 is disposed between the rib 36 and the degaussing coil 35. That is, the flange 922 covers a part of the side surface of the inner hole of the degaussing coil 35, and the creeping distance between the degaussing coil 35 and the degaussing coil 34 is increased. Therefore, good insulation between both coils can be obtained.

  The member that insulates the coils is not limited to insulating paper, and may be a molded product of insulating resin. As the material of the insulating member, any material having excellent insulating properties and heat resistance may be used. For example, PI film, PPS film, glass cloth film, and aramid paper are applicable. Further, as shown in FIG. 14, the flange portion 932 may be provided so as to surround not only the plane portion but the entire inner peripheral surface.

  As described in detail above, the fixing device 100 according to the present embodiment is an electromagnetic induction heating type fixing device, and the magnetic flux generation unit 3 is provided outside the fixing roller 1 along the axial direction thereof. In the magnetic flux generator 3, the demagnetizing coils 34 and 35 are placed on the exciting coil 31 so as to overlap each other. Each coil is wound around various ribs having a coil positioning function. Therefore, the positioning accuracy of each coil is high.

  Further, an insulating paper 91 provided with an inner hole 911 through which the ribs 36 and 37 can pass is sandwiched between the exciting coil 31 and the degaussing coil 34. On the inner peripheral surface of the insulating paper 91, there is a flange portion 912, and the flange portion 912 covers the inner peripheral side surface of the degaussing coil 34 which is an upper layer coil bundle. Therefore, the creeping distance between the exciting coil 31 and the degaussing coil 34 is large, and good insulation is obtained between the two coils. Therefore, an electromagnetic induction heating type fixing device is realized in which the insulation failure between the mounted coils is suppressed without impairing the positioning accuracy of the coils.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, in the embodiment, the present invention is applied to a laser printer, but the present invention is not limited to this. That is, even a copying machine, scanner, FAX, word processor, or the like can be applied as long as it has a fixing device. Moreover, it is not limited to color but may be dedicated to monochrome images. Further, a tandem method or a four-cycle method may be used.

  In the embodiment, the fixing roller is heated. However, the present invention is not limited to this. For example, a type in which a fixing belt heated by a magnetic flux generation unit is provided and the fixing belt and a pressure roller are arranged to face each other may be used.

  Further, the magnetic flux generator 3 of the embodiment has a three-layer structure of the exciting coil 31 and the demagnetizing coils 34 and 35, but is not limited to this. For example, a two-layer structure may be used. Of course, a structure of four or more layers may be used.

  In the magnetic flux generation unit 3 according to the embodiment, since the sheet conveyance path is based on the center of the fixing roller 1 in the axial direction, the demagnetizing coils 34 are arranged at both ends. For example, the degaussing coil may be arranged only at one end.

1 is a diagram illustrating a schematic configuration of a printer according to an embodiment. 1 is a diagram (front view) illustrating a schematic configuration of a fixing device according to an embodiment; 1 is a diagram (side view) showing a schematic configuration of a fixing device according to an embodiment; 1 is a block diagram illustrating a schematic configuration of a fixing device according to an embodiment. It is the perspective view seen from the magnetic flux generation part side of the fixing device concerning an embodiment. FIG. 3 is a perspective perspective view seen from the magnetic flux generation unit side of the fixing device according to the embodiment. It is the figure which looked at the inner side of a coil bobbin from the magnetic flux generation part side. It is a figure which shows the loading state (3 layers) of the coil in a magnetic flux generation part. It is a figure which shows the shape of the insulating paper (between an exciting coil and a degaussing coil) concerning embodiment. It is a figure which shows the state which loaded the insulating paper on the exciting coil. It is a figure which shows the loading state (2 layers) of the coil in a magnetic flux generation part. It is a schematic sectional drawing which shows the creeping distance between the coils concerning embodiment. It is a figure which shows the shape of the insulating paper (between a degaussing coil and a degaussing coil) concerning embodiment. It is a figure which shows the insulating paper in which the collar part was provided in the whole inner periphery. It is a figure which shows the shape of the insulating paper concerning the conventional form. It is a schematic sectional drawing which shows the creeping distance between the coils concerning the conventional form.

Explanation of symbols

1 Fixing roller (heated rotating body)
2 Pressure roller 3 Magnetic flux generator 31 Exciting coil 32 Magnetic core 33 Coil bobbins 34, 35 Demagnetizing coils 36, 37, 38 Ribs 91, 92 Insulating paper 911, 921 Inner holes 912, 922 Gutter 100 Fixing device

Claims (6)

A heating rotator provided with a heat generating layer that generates electromagnetic induction heat, and is positioned on the outer peripheral side of the heating rotator, and is disposed opposite to the heating rotator along the axial direction of the heating rotator, and generates magnetic flux by power supply. In an electromagnetic induction heating type fixing device having a magnetic flux generator,
The magnetic flux generator is
A bobbin facing the heating rotator;
A strut portion provided on the bobbin and fixedly disposed in the magnetic flux generation portion;
A first coil mounted on the bobbin and wound on the support post;
A second coil loaded on the first coil and wound around the support;
An insulating member provided with an inner hole that is sandwiched between the first coil and the second coil and penetrates the support column;
The fixing device according to claim 1, wherein the insulating member includes a flange portion that protrudes toward the first coil side or the second coil side at an inner peripheral portion that forms the inner hole. The fixing device according to claim 1,
The fixing device is characterized in that a height of the flange portion is higher than a height of a coil bundle located on a protruding side of the first coil and the second coil. In the fixing device according to claim 1 or 2,
The fixing device according to claim 1, wherein the first coil is an exciting coil, and the second coil is a degaussing coil. In a magnetic flux generation unit used in an electromagnetic induction heating type fixing device and having a magnetic flux generation unit that generates magnetic flux by power feeding,
The magnetic flux generator is
With bobbin,
A strut portion provided on the bobbin and fixedly disposed in the magnetic flux generation portion;
A first coil mounted on the bobbin and wound on the support post;
A second coil loaded on the first coil and wound around the support;
An insulating member provided with an inner hole that is sandwiched between the first coil and the second coil and penetrates the support column;
The magnetic flux generating unit, wherein the insulating member includes a flange portion protruding toward the first coil side or the second coil side on an inner peripheral portion forming the inner hole. The magnetic flux generation unit according to claim 4,
The height of the said collar part is higher than the height of the coil bundle located in the protrusion side among the said 1st coil and the said 2nd coil, The magnetic flux generation unit characterized by the above-mentioned. In the magnetic flux generation unit according to claim 4 or 5,
The magnetic flux generating unit, wherein the first coil is an exciting coil and the second coil is a degaussing coil.

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