KR100739685B1 - Apparatus for forming image on the print media - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for fixing a printing toner to a printing paper, and more particularly, to a fixing apparatus capable of electrically separating a heating element from a power supply unit by generating a heating element using an induced current generated from a transformer. The image fixing apparatus according to the present invention receives an alternating current and generates an induction current corresponding to the alternating current, a heating element generated by the generated induction current, and receiving heat generated from the heating element. A toner fixing unit for fixing the printing toner to a printing paper and an expansion tube sealing unit for fixing the heating element to the inside of the toner fixing unit by a predetermined size of pressure. The image fixing apparatus according to the present invention has a thin insulating layer for preventing only a short circuit of the toner fixing unit and the heating element between the toner fixing unit and the heating element by electrically separating the power supply unit and the heating element by the insulating unit. Therefore, heat generated in the heating element is efficiently transferred to the toner fixing unit, and the fixing unit can be quickly heated from the normal temperature to the target fixing temperature.

Description

Image fixing unit, fixing unit, heat generating unit and power supply unit for fixing toner on printing paper {Apparatus for forming image on the print media}

1 is a cross-sectional view schematically showing a fixing unit of an image fixing apparatus using a halogen lamp as a heat source.

2 shows a functional block diagram of an image fixing apparatus for generating heat to a fixing apparatus.

FIG. 3 illustrates a fuser used in the image fixing device of FIG. 2. FIG. 3A illustrates a cross-sectional view of the fuser in the image fixing device in which the heat generating portion of the fuser is tightly fixed to the fixing roller. FIG. The heat generating portion of the fixing unit shown in FIG. Is shown in detail.

4 shows a functional block diagram of an image fixing device corresponding to one embodiment of the present invention.

Fig. 5 shows a functional block diagram of an image fixing device corresponding to another embodiment of the present invention.

FIG. 6A shows a cross-sectional view of a fixing unit used in the image fixing apparatus of FIG. 4 or 5, and FIG. 6B shows a heating part of the fixing unit shown in FIG. 6A in detail.

FIG. 7 shows in more detail the fuser used in the image fixing device of FIG. 4 or 5.

FIG. 8 illustrates a close state of the heat generating portion, the fixing roller portion, and the expansion-contacting portion of the fixing unit used in the image fixing apparatus of FIG. 4 or FIG. 5.

FIG. 9 is data comparing warm-up times of a fuser using a halogen lamp as a heat source, and a fuser in which a fixing roller unit and a heat generating unit are tightly fixed to each other.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for fixing a printing toner transferred to a predetermined image onto a printing paper. More specifically, the heating element of the fixing unit is generated by using an induced current generated from a transformer to electrically separate the heating element from the power supply unit. It relates to a fixing device that can be.

Conventional image printing apparatuses are provided with a fixing apparatus for applying a constant pressure and heat to the printing toner in order to fix the toner transferred to a predetermined image onto the printing paper. The fixing apparatus includes a fixing unit for applying a constant heat to the printing toner, and a pressurizer for applying a constant pressure, wherein the fixing unit generates a heat generating element for generating heat for fixing the toner on the printing paper and heat generated from the heating element. It includes a fixing roller unit for receiving and transferring to the printing paper.

1 is a lateral cross-sectional view schematically showing a fixing unit of an image fixing apparatus using a halogen lamp as a heat source. Referring to FIG. 1, the fixing unit 10 includes a fixing roller unit 11 and a heat generator 12 made of a halogen lamp installed at the center thereof. On the surface of the fixing roller part 11, a coating layer 11a made of Teflon is formed. The heat generating element 12 generates heat in the fixing roller part 11, and the fixing roller part 11 is heated by radiant heat transmitted from the heat generating element 12.

Conventional fusers using halogen lamps as a heat source have a warm-up time of several tens of seconds to several minutes to heat up the fixing roller unit until the target fixing temperature is reached. Require. Thus, the user was inconvenient to wait long long-ham time to print the image.

On the other hand, in the conventional fuser using a halogen lamp as a heat source, in order to reduce the warm-up time, the temperature of the fixing roller portion is maintained at a constant temperature for a predetermined time even when no printing operation is performed, and thus there is a lot of power consumption.

A first technical problem to be achieved by the present invention is to provide an apparatus for generating a heating element through an induced current generated in an insulating portion for fixing a toner transferred to a predetermined image on a printing sheet.

The second technical problem to be achieved by the present invention is to provide a power supply for supplying the induced current generated in the insulation to the fuser.

The third technical problem to be achieved by the present invention is to provide a fixing unit having a thin insulating layer by electrically separating the power supply unit and the heating element.                         

The fourth technical problem to be achieved by the present invention is to provide a fixing apparatus capable of warming up the fixing apparatus in a short time.

The toner fixing heating apparatus for achieving the first technical problem of the present invention includes an insulation unit which receives a predetermined alternating current and generates an induction current corresponding to the alternating current, and a heating element that is resistively generated by the generated induction current. Characterized in that.

Preferably, the insulator is a transformer that receives an alternating current and generates an induced current corresponding to the alternating current.

The power supply of the fuser for achieving the second technical problem of the present invention is to receive a predetermined alternating current to generate an induction current corresponding to the input alternating current, the insulation for providing the generated induction current to the fuser It is characterized by including a wealth.

Preferably, the insulation unit is characterized in that the transformer receives the alternating current to generate a corresponding induced current.

Preferably, the power supply unit of the fuser rectifies the alternating current to generate a direct current and an alternating current using the direct current to generate an alternating current, the alternating current generating unit for providing the generated alternating current to the insulation unit It further comprises.

A fuser for achieving the third technical problem of the present invention is characterized in that it comprises a heating element for generating a heat generated by a predetermined induction current and a toner fixing unit for fixing the toner on the printing paper by receiving the heat generated from the heating element. .

Preferably, the fixing unit further comprises an insulating layer between the heating element and the toner fixing unit to insulate the heating element and the toner fixing unit, wherein the withstanding voltage of the insulating layer is 1 kv or less.

A fixing device for achieving the fourth technical problem of the present invention is a power supply unit for receiving a predetermined alternating current and generating a corresponding first induced current, and generates heat by the generated first induced current and uses the generated heat. And a fixing unit for fixing the toner to a printing sheet.

Preferably, the fixing unit includes a heating element that generates resistance heat by the generated first induced current and a toner fixing unit which receives the heat generated by the heating element and fixes the toner on a printing paper, wherein the heating element and the toner fixing unit The breakdown voltage is characterized in that less than 1kv.

Preferably, the heating element generates a second induction current in the toner fixing unit by the first induction current, and the toner fixing unit is adapted to the resistance heating of the heating element caused by the first induction current and the second induction current. Heated by induction heat generation of the toner fixing unit.

Hereinafter, an image fixing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

2 illustrates a functional block diagram of an image fixing apparatus for generating heat of a fixing roller. The image fixing apparatus of FIG. 2 includes a power supply unit 210, a line filter unit 220, a conduction switch 230, and a fixing unit ( 240). The power supply unit 210 provides an alternating current, and the line filter unit 220 removes a high frequency component acting as a noise from the alternating current. The conduction switch 230 provides or blocks the current from which the high frequency component is removed from the line filter unit 220 to the fixing unit 240 by opening and closing the conduction switch 230. The fixing unit 240 includes a heating unit 250 and a fixing roller unit (not shown), and the heating unit 250 is an insulating layer (not shown) for insulating the heating coil (not shown) and the fixing roller unit. ). Hereinafter, the fuser 240 will be described in more detail with reference to FIG. 3. The heating coil is resistance-heated by the alternating current provided from the line filter unit 220. The heat generated by the heating coil is transferred to the fixing roller through the insulating layer, and when the printing paper passes through the fixing roller, the fixing roller dissolves the print toner on the printing paper and fixes it on the printing paper.

3 illustrates the fixing unit of FIG. 2 in more detail. FIG. 3A illustrates a longitudinal cross-sectional view of the fixing unit 240 in which the heat generating unit 250 is fixed and adhered to the fixing roller unit, and FIG. 3B is illustrated in FIG. 3A. The heat generating part 250 of the fixing unit 240 is shown in detail. The fixing unit 240 has a cylindrical fixing roller part 320 having a protective layer 310 coated with Teflon, etc. on the surface thereof, and is installed inside the fixing roller part 320 to open both ends thereof. Expansion pipe contact portion 350, the fixing roller 320 and the expansion pipe contact portion 350 is provided between the heat generating portion (250). The heating unit 250 is installed to surround the expansion pipe contacting portion 350 in a spiral manner to surround the heating coil 360 and the heating coil 360 to generate heat by receiving a current from an external power source. Insulation layers 330 and 340 are provided to insulate the expansion pipe contact part 350 and the fixing roller part 320 so that insulation breakdown does not occur when a current is input to the heating coil 360 and leakage current does not flow.

The fixing roller 320 is heated by heat transferred from the heating coil 360 to fuse the printing toner to the printing paper. Preferably, the fixing roller 320 may be made of stainless steel, aluminum (Al), or copper (Cu).

The insulating layers 330 and 340 are formed between the first insulating layer 330 and the heating coil 360 and the expansion-contacting portion 350 provided between the fixing roller part 320 and the heating coil 360. The second insulating layer 340 is provided in the.

The first and second insulating layers 330 and 340 may be made of magnesium oxide (MgO) sheet or glass sheet. Heat generated from the heating coil 360 is transferred to the fixing roller part 320 and the expansion-contacting part 350 through the first insulating layer 330 and the second insulating layer 340, respectively.

The insulating material used for the insulating layers 330 and 340 should have a breakdown voltage characteristic and dielectric breakdown resistance. The breakdown voltage property indicates a property that can withstand a predetermined external power supply, and the breakdown resistance property is a property in which leakage current does not occur more than 10 mA and breakdown does not occur for 1 minute under the maximum breakdown voltage. Each country requires a predetermined withstand voltage between the fixing roller part 320 and the heating coil 360. In order to satisfy the required magnitude of the withstand voltage, the first insulating layer 330 and the second insulating layer 340 should be inserted between the fixing roller part 320 and the expansion close contact part 350.

FIG. 3B illustrates a portion A of FIG. 3A, that is, the heat generating part 250 of the mounter 240 in more detail. For example, when the withstand voltage required between the fixing roller part 320 and the heating coil 360 is 6kv, the first insulating layer 330 may have three mica sheets 330a and 330b having a thickness of 0.18 mm. 330c) should be used. As the thickness of the insulating layer inserted between the fixing roller part 320 and the heating coil 360 becomes thicker, the amount of heat generated by the heating coil 360 is transferred to the fixing roller part 320. .

4 is a functional block diagram of an image fixing apparatus according to an embodiment of the present invention. The image fixing apparatus of FIG. 4 includes a power supply unit 410, a line filter unit 420, a rectifying unit 430, and an alternating current. The fixing unit 440 includes a generator 440, an insulation unit 450, and a heat generating unit 470. Hereinafter, the fixing unit 460 of FIG. 4 will be described in more detail with reference to FIG. 6. The power supply unit 410 provides an alternating current having a predetermined size and frequency. The line filter unit 420 includes an inductor L1 and a capacitor C1, and receives the AC power from the power supply unit 410 to remove the high frequency component included in the AC current. The line filter unit 420 is an example for explaining the present invention, and another type of line filter unit 420 may be used, which is included in the scope of the present invention.

The rectifier 430 rectifies the AC current provided by the line filter 420 to generate a current of a DC component. The rectifier shown in FIG. 4 is a bridge rectifier composed of four diodes D1, D2, D3, and D4, and rectifies an alternating current into a direct current component according to the four diode polarities. Other types of rectifiers may be used to rectify the alternating current to produce a direct current component, which is within the scope of the present invention.

The AC current generator 440 receives the current of the DC component provided from the rectifier 430 to generate an AC current. The alternating current generator 440 illustrated in FIG. 4 includes two capacitors C2 and C3 and two switches SW1 and SW2, and the DC current rectified by the rectifier 430 by opening and closing the switch. Is converted into alternating current. The AC current generating unit 440 receives the DC current generated by the rectifying unit 430 according to the field to which the present invention is applied and generates a high frequency or low frequency AC current. In order to change the direct current into alternating current, other kinds of alternating current generators can be used, which is within the scope of the present invention.

The insulation unit 450 generates an induced current using the alternating current generated by the alternating current generator 440. The insulation unit 450 generates an induction current using the current input from the power supply unit 410, and provides the generated induction current to the heating unit 470. The heating unit 470 may include a heating element (not shown) that generates resistance heat using the induced current, and a thin insulating layer (not shown) to prevent a short circuit between the heating element and the toner fixing unit (not shown) of the fixing unit 460. City). Rather than providing the current of the power supply unit 410 directly to the heating element, the induction current generated by using the insulation unit 450 is provided to the heating element, so that the insulation unit 450 is connected to the power supply unit 410 and the heating element. It electrically insulates. Hereinafter, a transformer will be described as an example of the insulation unit 450. Preferably, the transformer is a high frequency transformer having a smaller volume than a low frequency transformer.

When an alternating current flows through the primary coil 452 of the transformer 450, a change in the magnetic field occurs around the secondary coil 454, and an induced current is generated in the secondary coil 454 by the changing magnetic field. The induced current generated by the transformer 450 is referred to as first induced current hereinafter. The first induced current generated by the transformer 450 is provided to the heat generating unit 470 of the fixing unit 460. The magnitude of the first induced current may be controlled by the turns ratio of the primary coil 452 and the secondary coil 454. The current of the power supply unit 410 flowing through the primary coil 452 of the transformer 450 generates an induction current in the secondary coil 454 of the transformer 450 by electromagnetic induction, and the generated induction current The heating unit 470 of the fixing unit 460 is provided. Since the secondary coil 454 is provided with the first induced current generated by the transformer 450 instead of the current of the power supply unit 410, the heating element of the power supply unit 410 and the heat generating unit 470 is electrically connected to the secondary coil 454. Are separated.

FIG. 5 illustrates an image fixing apparatus according to another embodiment of the present invention. The image fixing apparatus of FIG. 5 includes a power supply unit 510, a line filter unit 520, a transformer 530, a conduction switch 540, and And a fixing unit 550 having a heat generating unit 560. The power supply unit 510, the line filter unit 520, and the fixing roller 540 are the same as the power supply unit 410, the line filter unit 420, and the fixing unit 460 described with reference to FIG. 4. However, the image fixing apparatus according to another embodiment of the present invention described in FIG. 5 does not include the rectifying unit 430 and the AC current generating unit 440. The conduction switch 540 provides or blocks a current from which the high frequency component is removed from the line filter unit 520 to the fixing unit 550 by opening and closing the switch 5400. The current of the power supply unit 510 flowing in the primary coil 532 of the transformer 530 generates a first induced current in the secondary coil 534 of the transformer 530 by the electromagnetic induction, the generated second One induced current is provided to the heat generating unit 560 of the fixing unit 550. Since the first induced current generated by the transformer 530 is provided to the heating element (not shown) of the heating unit 560, the power supply unit 510 and the heating unit 560 are provided. The heating elements are electrically separated from each other.

In the image fixing circuits of FIGS. 4 and 5, the heating units 470 and 560 of the fixing units 460 and 550 are electrically separated from the power supply units 410 and 510 by the transformers 450 and 530. Thus, in the image fixing circuits of FIGS. 4 and 5, the heat generating parts 470 and 560 of the fixing units 460 and 550 do not require the thick insulating layers 330a to 330c as in the fixing unit shown in FIG. 3. A thin insulating layer is required such that the heating elements and the toner fixing portions of the heat generating parts 470 and 550 are not shorted to each other, and preferably the withstand voltage of the insulating layer 630 is 1 kV or less.

Referring to FIG. 6 of the present invention, the fixing units 460 and 550 of FIGS. 4 and 5 will be described in more detail. FIG. 6A illustrates a cross-sectional view of the fixing units 460 and 550 used in the image fixing apparatus of FIG. 4 or 5, and FIG. 6B illustrates the heat generating units 470 and 560 of the fixing units 460 and 550 shown in FIG. 6A. Is shown in detail.

First, referring to the side cross-sectional view of the fixing unit (460, 550) with reference to Figure 6a, the fixing unit (460, 550) is a cylindrical toner fixing unit formed with a protective layer 610 coated with Teflon or the like on the surface 620, a tubular expansion contact 650 installed inside the toner fixing unit 620 and open at both ends, and disposed between the toner fixing unit 620 and the expansion contact 650. The heat generating parts 470 and 560 are provided. The heat generating parts 470 and 560 are installed to surround the expansion pipe contact part 650 in a spiral manner to surround the heat generating element 660 and the heat generating element 660 which generate heat by receiving current from an external power source. Insulation layers 630 and 640 are provided to insulate the heating element 660 from being short-circuited with the toner fixing unit 620 and the expansion-contacting unit 650.

Although the fixing roller unit is illustrated as an example of the toner fixing unit 620 in the fixing units 460 and 550 illustrated in FIG. 6A, another type of toner fixing unit 620 may be used according to the field to which the present invention is applied. Which is within the scope of the present invention. Hereinafter, the toner fixing unit 620 will be described as a fixing roller unit.

On the other hand, preferably, the heating element 660 is characterized in that the coil. Other kinds of heating elements according to the field to which the present invention is applied may be used, which is within the scope of the present invention.

The coil generates resistance heat by the first induced current generated by the transformers 450 and 530. In addition, the first induced current generated by the transformers 450 and 530 is an alternating current corresponding to the alternating current input to the transformers 450 and 530. When the first induced current, which is an alternating current, is input to the coil, an alternating magnetic flux 360 that changes corresponding to the first induced current is generated around the coil. The generated alternating magnetic flux 360 is chained to the fixing roller unit 620, and the fixing roller unit 620 generates an eddy current in a direction to prevent a change in the alternating alternating magnetic flux 360. The induced current generated by the fixing roller unit 620 by the alternating alternating magnetic flux is referred to as a second induced current. The fixing roller 620 may be formed of a copper alloy, an aluminum alloy, a nickel alloy, an iron alloy, a chromium alloy, a magnesium alloy, and the like, and the fixing roller 620 may have its own resistivity. 2 The resistance is generated by the induced current. Hereinafter, the fixing roller unit 620 generates heat by the second induced current is called induction heating. According to the field to which the present invention is applied, the fixing roller unit 620 may be manufactured using different materials, which belongs to the scope of the present invention.

The heating element 660 is a copper alloy, aluminum alloy, nickel alloy, the resistance of both ends of the heating element 660 is less than 100 Ohm (Ohm) to ensure that the resistance is generated by the resistance loss of the heating element 660 when the current is input Iron alloys, chromium alloys can be used. According to the field to which the present invention is applied, the heating element 660 may be manufactured using different materials, which belongs to the scope of the present invention.

The insulating layers 630 and 640 are installed between the first insulating layer 630 disposed between the fixing roller part 620 and the heating element 660, the heating element 660, and the expansion-adhesive contact part 650. The second insulating layer 640 is formed. The first and second insulating layers 630 and 640 may include mica, polyimide, ceramic, silicon, polyurethane, glass, and PTFE. It can be produced as. According to the field to which the present invention is applied, the insulating layers 630 and 640 may be manufactured using different materials, which belong to the scope of the present invention.

FIG. 6B illustrates in detail the portion B of FIG. 6A, that is, the heat generating parts 470 and 560 of the mounter. The heat generating parts 470 and 560 have an insulating layer between the heat generating element 660 and the fixing roller part 620. The insulating layer 630 is for preventing the heating element 660 from being short-circuited to the fixing roller part 620, and a thin insulating layer which prevents only a short circuit is inserted into the heating element 660 and the fixing roller part 620. . Preferably, the withstand voltage of the insulating layer 630 is characterized in that less than 1kv. In order to satisfy the withstand voltage requirement of 1 kV or less, for example, the insulating layer 630 of the heat generating parts 470 and 560 may have a 0.1 mm mica sheet to prevent a short circuit between the heat generating element 660 and the fixing roller part 620. Chapter 1 is used. Preferably, when one sheet of 0.1mm mica sheet is damaged, two sheets of 0.1mm mica sheet may be used to prevent the fixing roller unit 620 and the heating element 660 from being short-circuited.

As the thickness of the first insulating layer 630 inserted between the fixing roller part 620 and the heating element 660 becomes thicker, heat generated in the heating element 660 may be efficiently applied to the fixing roller part 620. It is not delivered. Therefore, as the thickness of the first insulating layer 630 is thinner, heat generated in the heating element 660 may be transmitted to the fixing roller part 620 more efficiently. Depending on the field to which the present invention is applied, different materials and different thicknesses of the first insulating layer 630 may be used, which is within the scope of the present invention.

FIG. 7 shows the fixing units 460 and 550 used in the image fixing apparatus of FIG. 4 or 5 in more detail. As shown in FIG. 6, the fixing units 460 and 550 may include a coating unit 610, a fixing roller unit 620, first and second insulating layers 630 and 640, a heating element 660, and expansion pipes. Part 650 is included. End caps 724 and power transmission end caps 730 are installed at both ends of the fixing units 460 and 550, respectively. The power transmission end cap 730 is similar in configuration to the end cap 724, but is connected to the drive unit 738 installed in the frame 732 supporting the fixing unit 460, 550, the fixing unit 460, Power transmission means such as a gear 740 for rotating the 550 is provided.

The end cap 724 has an air vent 726 formed therein. The pore 726 is the end cap 724 is installed in the fixing unit (460, 550) and the internal space 728 and the outside of the fixing unit to allow air to pass through the pressure of the inner space 728 of the fixing unit Maintain atmospheric pressure.

Therefore, even when the expansion pipe contact part 650 is heated by the heat transferred from the heating element 660, the internal space 728 passes external air through the pores 726, so that atmospheric pressure is maintained. The pore 726 may be provided in the power transmission end cap 730. In addition, the pores 726 may be provided in both the end cap 724 and the power transmission end cap 730.

The end cap 724 and the power transmission end cap 730 are provided with electrodes 722, respectively. The electrode 722 is electrically connected to the lead portion 734. The current supplied from the external power source 742 is supplied to the heating element 660 via the brush 736, the electrode 722, and the lead 734.

FIG. 8 illustrates a close contact state of the heat generating parts 470 and 560, the fixing roller part 620, and the expansion-contacting part 650 of the fixing unit 460 and 550 used in the image fixing apparatus of FIG. 4 or 5. . In the fixing units 460 and 550 illustrated in FIG. 8, a heating coil is illustrated as an example of the heating element 660.

In order to efficiently transfer heat generated from the heating coil 660 of the heat generating parts 470 and 560 to the fixing roller part 620, the first and second insulating layers 630 and 630 of the heat generating parts 470 and 560 are provided. There should be no air gap between 640 and the heating coil 660. In the present invention, the heating coil 660 and the first and second insulating layers 630 and 640 of the fixing unit 460 and 550 are plastically deformed by expansion pressure applied from the expansion-contacting part 650, and plastically deformed heat generation. The parts 470 and 560 are closely fixed to the fixing roller part 620 and the expansion pipe contact part 650. Preferably, the expansion tube is made of a non-magnetic material or a pipe of a type that does not form a closed loop. For example, a metal pipe, a coil spring, a foam urethane, a plastic pipe, or the like may be used as the expanding contact portion 650.

The proper expansion pressure applied to the expansion pipe contact part 650 is such that the circumferential expansion pressure of the expansion pipe contact part 650 reaches the stress distribution σ of the material of the expansion pipe contact part 650 so that permanent plastic deformation occurs. Is determined. The expansion pressure applied to the expansion tube tight portion is determined by the following equation (1).

[Equation 1]

P = σ × t / r

Where P is the expansion pressure, sigma is the stress distribution, t is the thickness of the expansion tube, and r is the radius of the expansion tube.

8A illustrates a case where an air layer exists between the fixing roller unit 620, the heating coil 660, and the insulating layers 630 and 640, and FIG. 8B illustrates the fixing roller unit 620 and the heating coil 660. ) And no air layer exists between the insulating layers 630 and 640. The fixing units 460 and 550 depending on whether there is an air layer in the heat generating units 470 and 560, that is, the degree of adhesion between the fixing roller unit 620, the heating coil 660, and the insulating layers 630 and 640. A difference of about 4 seconds to 5 seconds occurs when the fixing roller unit 620 of the () is heated to a target fixing temperature.

FIG. 9 illustrates a fixing apparatus using a halogen lamp as a heat source, and a fixing apparatus in which the fixing roller unit 620 and the heat generating units 470 and 560 are tightly fixed to each other (hereinafter referred to as an e-coil fixing unit). Experimental data comparing the time taken to heat the fixing roller unit to the target fixing temperature of the fixing unit. In the present experiment, the first and second insulating layers of the two-coil type fixing unit use a mica sheet, the fixing roller portion has a radius of 32 mm, and the fixing roller portion is made of aluminum. As shown in FIG. 9, it takes 75 seconds to heat the fixing roller unit from a normal temperature of 20 ° C. to a target fixing temperature of 180 ° C. in a fuser using a halogen lamp as a heat source.

On the other hand, in the case of forming an insulating layer using three or two 0.18 mm mica sheets in an e-coil fixing unit, the breakdown voltages between the fixing roller unit 620 and the heating element 660 are 6kv and 4.2kv, respectively. In this case, it takes 34 seconds and 24 seconds to heat the fixing roller unit 620 of the fixing unit to a target fixing temperature of 180 ° C. at room temperature of 20 ° C., respectively. In the case of forming an insulating layer using three or two 0.15 mm mica sheets in an e-coil fixing device, the breakdown voltages between the fixing roller part 620 and the heating element 660 are 4.8kv and 3kv, respectively. It takes 27 seconds and 14 seconds to heat the fixing roller 620 to a target fixing temperature of 180 ° C from room temperature of 20 ° C, respectively. In the case of forming an insulating layer using three, two or one 0.1 mm mica sheets in an e-coil fixing device, the breakdown voltages between the fixing roller part 620 and the heating element 660 are 3.3 kv and 2.3 kv, respectively. , 1.4kv, and in this case, it takes 16 seconds, 10 seconds, and 6 seconds to heat the fixing roller unit 620 to a target fixing temperature of 180 ° C. at room temperature of 20 ° C., respectively.

As shown in FIG. 9, the warm-up time for heating the fixing roller part to a target fixing temperature in a fuser using halogen as a heat source is a warm-ham for heating the fixing roller part to a target fixing temperature in an e-coil type fixing machine. Considerably longer than time. On the other hand, it can be seen that the longer the thickness of the insulating layer in the e-coil fixing device, the longer it takes to heat the fixing roller from the room temperature to the fixing target temperature.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Accordingly, the true technical protection scope of the present invention is defined by the technical spirit of the appended claims.

The image fixing device according to the present invention has a thin insulating layer for preventing the fixing roller portion from being short-circuited to the heating coil by electrically separating the power supply portion and the heating coil by the transformer. By having a thin insulating layer, heat generated in the heat generating coil is efficiently transferred to the fixing roller portion, and thus, the fixing roller portion can be quickly heated from the normal temperature to the target fixing temperature.

In addition, since the fixing roller portion can be quickly heated from the normal temperature to the target fixing temperature, it is not necessary to maintain the temperature of the fixing roller portion above a certain temperature for a predetermined time even when there is no printing operation, thus preventing unnecessary power waste. .

Claims (46)

A fuser heating device for fixing toner on a printing sheet, A power supply unit supplying a predetermined alternating current; An insulator configured to receive the alternating current and generate an induced current corresponding to the alternating current; And It includes a heating element that generates resistance heat by the generated induced current, And the insulating part electrically separates the power supply part and the heating element. delete The method of claim 1, wherein the insulating portion Heat generating device of the fixing unit, characterized in that the transformer. 4. The transformer of claim 3, wherein the transformer is A heat generating device of a fixing unit, characterized in that the high frequency transformer. The method of claim 3, wherein the heating element A heat generating device of the fixing unit, characterized in that the coil. The method of claim 1, A rectifier for rectifying the alternating current to generate a direct current; And And an alternating current generating unit for generating an alternating current using the direct current and providing the generated alternating current to the heating element. The method of claim 6, wherein the AC current generating unit A heat generating device of a fuser, characterized in that for generating a high frequency alternating current. The method of claim 6, And a line filter unit for removing high frequency noise components from an alternating current inputted to the rectifier. A power supply for supplying power to a fixing unit for fixing toner on printing paper, A power supply unit providing a predetermined alternating current; And And an insulator configured to receive the alternating current to generate an induced current corresponding to the input alternating current, and to provide the generated induced current to the fuser. The method of claim 9, wherein the insulating portion And a power supply electrically separating the power supply unit and the fixing unit. The method of claim 10, wherein the insulating portion Power supply, characterized in that the transformer. The method of claim 11, wherein the transformer is Power supply characterized in that the high frequency transformer The method of claim 9, A rectifier for rectifying the alternating current to generate a direct current; And And an alternating current generating unit for generating an alternating current using the direct current and providing the generated alternating current to the insulation unit. The method of claim 13, wherein the AC current generating unit A power supply characterized by generating a high frequency alternating current. The method of claim 13, And a line filter unit for removing high frequency noise components from an alternating current input to the rectifying unit. In the fixing unit for fixing the toner to the print paper, A heating element to which a predetermined induction current is input and which generates resistance heat; A toner fixing unit which receives the heat generated by the heat generating unit and fixes the toner on a printing sheet; And And a first insulating layer existing between the heating element and the toner fixing unit. delete The method of claim 16, The fuser is characterized in that the coil is a coil. The method of claim 18, A fuser, characterized in that the withstand voltage of the first insulating layer is less than 1kv. 19. The method of claim 18, wherein the material of the first insulating layer is A fuser, characterized in that any one of mica, polyimide, ceramic, ceramic, silicon, polyurethane, glass, and PTFE (polytetrafluoruethylene). The method of claim 20, The first insulating layer is made of mica, and the first insulating layer has a thickness of 0.2 mm or less. The method of claim 18, And the heat generating portion is in close contact with the toner fixing portion. The method of claim 22, And a close contact part present in the toner fixing part and in close contact with the heat generating part on the toner fixing part at a side opposite to the toner fixing part. The method of claim 23, wherein the contact portion And an expansion tube tight contact portion for tightly fixing the heat generating portion to the toner fixing portion by expansion tube pressure of a predetermined size. The method of claim 23, wherein A fixing unit further comprising a second insulating layer between the sealing unit and the heating element. In the fixing unit for fixing the toner to the print paper, A heat generator configured to generate a resistance by inputting a predetermined induction current; A fixing roller which receives the heat generated by the heat generating unit and fixes the toner on the printing paper, The heating unit is characterized in that the fixing roller electrically separated from the fixing roller. The method of claim 26, wherein the heating portion A heating element to which a predetermined induction current is input and which generates resistance heat; And And a first insulating layer between the heating element and the fixing roller. The method of claim 27, The fuser is characterized in that the coil is a coil. The method of claim 28, A fuser, characterized in that the withstand voltage of the first insulating layer is less than 1kv. 29. The method of claim 28, wherein the material of the first insulating layer A fuser, characterized in that any one of mica, polyimide, ceramic, ceramic, silicon, polyurethane, glass, and PTFE (polytetrafluoruethylene). The method of claim 30, The first insulating layer is made of mica, and the first insulating layer has a thickness of 0.2 mm or less. The method of claim 27, The fixing unit is characterized in that the heat generating unit is in close contact with the fixing roller. The method of claim 32, The fusing unit is characterized in that the fixing unit rotates with the fixing roller. The method of claim 32, A fixing unit which is present in the fixing roller and is in close contact with the fixing roller to the heat generating portion in close contact with the fixing roller. The method of claim 34, wherein the contact portion A fixing unit, characterized in that the expansion close contact portion for tightly fixing the heating portion to the fixing roller by the expansion pressure of a predetermined size. The method of claim 34, wherein The heat generating unit is a fixing unit, characterized in that rotates together with the reconnaissance roller and the contact portion. The method of claim 34, wherein A fixing unit further comprising a second insulating layer between the sealing unit and the heating element. A fixing apparatus for fixing toner on printing paper, A power supply unit receiving a predetermined AC current to generate a corresponding first induced current; And A fixing unit configured to generate resistance heat and induction heat by the generated first induced current and to fix the toner on a printing sheet by using the generated heat; And the power supply unit is electrically separated from the fixing unit. The method of claim 38, wherein the power supply unit A power supply unit supplying a predetermined alternating current; A rectifier for receiving the AC current to generate a DC current; An alternating current generator for generating an alternating current using the direct current; And And an insulation unit configured to receive an alternating current from the alternating current generating unit to generate a corresponding first induced current, and to provide the first inductive current to the fixing unit. The method of claim 39, wherein the insulating portion A fixing device, characterized in that for electrically separating the AC current generating unit and the fixing unit. The method of claim 40, wherein the insulating portion A fixing device, characterized in that the transformer. The method of claim 38, wherein the fixing unit A heat generating unit that generates resistance alternating heat generated by the generated first induced current and generates an alternating magnetic flux that is changed by the first induced current; And a toner fixing unit configured to generate a second induced current by the alternating magnetic flux, and to generate a resistance heat by the second induced current. The method of claim 42, wherein the heating portion A coil that is resistance-heated by the generated first induced current and generates an alternating magnetic flux that is changed by the first induced current; And And an insulating layer existing between the coil and the toner fixing unit. The method of claim 43, Fixing apparatus, characterized in that the withstand voltage of the insulating layer is 1kv or less. The method of claim 43, And a close contact portion present inside the toner fixing portion and in close contact with the heat generating portion at the side opposite to the toner fixing portion. The method of claim 45, And the toner fixing unit is a fixing roller, and the heat generating unit rotates together with the fixing roller and the close contact unit.

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