JP2002158087A - Electromagnetic induction heating coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic induction heating coil which has high heating efficiency, is capable of shortening of warm-up time and of quick start as well as power saving. SOLUTION: The electromagnetic induction heating coil 1, which is arranged by winding coil inside a heating roller constituting a heating and fixing device, comprises a dividing coil M2 and dividing coils M1, M3 located at both sides of the dividing coil M2, and at same time, is connected to a power circuit 9 through a switch SW1 (SW2) so as to be switched over from the time when the heating roller covers the heating range of the dividing coil M2 alone to the time of series connection of all the dividing coils M1, M2, M3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction heating coil which is wound and disposed in a longitudinal direction in a heating roller constituting an image forming apparatus such as a copying machine. The present invention relates to an electromagnetic induction heating coil capable of saving power.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine or a printer is provided with a heat fixing device for forming an image, and is covered by an appropriate image forming means such as an electrophotographic process, an electrostatic recording process, and a magnetic recording process. An image is formed on a recording material (transfer material sheet, electrostatic recording paper, electrofax paper, printing paper, etc.) by a transfer type or a direct type, and an unfixed image (toner image) corresponding to the target image information is recorded. A permanent image is fixed on the surface of the material by heating. As a specific example of such a heat fixing device, as shown in FIG.
A heating / fixing device 6 having a structure in which a halogen lamp 4 serving as a heating source is inserted and rotatably disposed inside a heating roller 3 made of aluminum or the like, and a pressure roller 5 is elastically contacted with the heating roller 3. It is heavily used.

In the heat fixing device 6 described above, when the halogen lamp 4 inserted inside the heating roller 3 generates heat and emits light, the heat is radiated and convection heats the heating roller 3 to heat the heating roller 3. Is to fix the permanent image on the surface of the recording material 2 with a uniform temperature distribution by heat conduction.

[0004]

However, a heat fixing device using a halogen lamp cannot cope with quick start because the time until the entire heating roller has a uniform temperature distribution, so-called warm-up time, is long. Was. Further, in order to cope with recent demands for power saving, switching the heating range according to the size of the recording material requires at least two halogen heaters having different lengths, and there is a problem that the mounting structure becomes complicated. Was. Further, in a standby state in which the image forming apparatus has stopped the printing operation, there is a problem that a complicated operation of adjusting the temperature of the heat fixing device to a standby temperature corresponding to the standby state is required.

Accordingly, an object of the present invention is to provide an electromagnetic induction heating coil which has a high heating efficiency, can shorten a warm-up time, can perform a quick start, and can cope with power saving.

[0006]

According to a first aspect of the present invention, there is provided an electromagnetic induction heating coil which is disposed in a longitudinal direction in a heating roller constituting a heat fixing device, wherein the electromagnetic induction heating coil is provided. Coil 1 is divided coil M2 and said divided coil M2
And the switch SW1 (SW2) is configured so that the heating range by the heating roller is switched between when the divided coil M2 is used alone and when the divided coils M1, M2, and M3 are connected in series. And an electromagnetic induction heating coil characterized by being connected to the power supply circuit 9 via the power supply circuit. Since the electromagnetic induction heating coil according to the first aspect has a high heating efficiency, the warm-up time can be reduced and quick start can be performed. Further, since the heating range can be switched according to the paper size, power saving can be achieved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings. 1A and 1B are simplified explanatory views showing an embodiment of the present invention. FIG. 1A is a simplified front view of an electromagnetic induction heating coil, and FIGS. 1B and 1C are connection examples of the electromagnetic induction heating coil. FIG. FIG. 2 is a perspective view illustrating a configuration of the heat fixing device. Note that the present invention is not limited by this.

First Embodiment In the drawings, reference numeral 1 denotes an electromagnetic induction heating coil, which is composed of a split coil M2 located inside and split coils M1 and M3 located on both sides of the split coil M2. . Divided coil M2 has nickel or manganese inside and Curie point of 200
A heat-resistant coil bobbin 7 made of phenol resin, ceramic, or the like and having an H-shape with a ferrite core (not shown) of a higher degree than that of
It is wound with 13 turns of 250mm, width 20mm and thickness 15mm. Similarly to the split coil M2, each of the split coils M1 and M3 is wound in the longitudinal direction of the heating roller 3 by 20 turns of 15 mm, 20 mm in width and 15 mm in thickness through an H-shaped coil bobbin 7 having a ferrite core mounted thereon. Have been. The electromagnetic induction heating coil 1 is provided with a switch SW1 or a switch SW2 so that the heating range of the heating roller 3 can be switched between when the split coil M2 is used alone and when the split coils M1, M2 and M3 are connected in series.
And is connected to the power supply circuit 9 to be energized. Needless to say, the switches SW1 and SW2 may be any of electrical or mechanical switches, such as semiconductor elements and relays, which are commonly used.

The split coils M1, M2, and M3 constituting the electromagnetic induction heating coil 1 are each composed of 10 to 60 heat-resistant urethane wires having a wire diameter of 0.1 mm to 0.6 mm, and each litz wire is formed by twisting 10 to 60 wires. The heat-resistant temperature of the electromagnetic induction heating coil 1 itself can be reduced. Therefore, even if, for example, a polyamide-imide copper wire, polyester-imide copper wire or the like having a heat-resistant temperature of 200 ° C. or less is used as a wire for forming the split coils M1, M2, and M3, the insulation characteristics do not deteriorate due to the high temperature.

Reference numeral 6 denotes a heat fixing device having a basic structure of a parallel pressure contact roller pair of a heating roller 3 and a pressure roller 5, which rotates the roller pairs 3, 5 and serves as a pressure contact portion between the roller pairs 3, 5 The recording material 2 to be image-fixed is introduced into the nip,
The unfixed image heated and melted by the heat of the heating roller 3 and the pressing force of the heating nip is soaked into the surface of the recording material 2 and thermally fixed. The electromagnetic induction heating coil 1 disposed inside the heating roller 3 is fixed (not shown) on the side surface so as not to contact the heating roller 3 and does not rotate. W indicates a paper passing range of the heating roller 3;
For example, the width is set to 280 mm to 340 mm for A3 or A4 landscape paper.

[0011] The electromagnetic induction heating coil having such a configuration is as follows.
The length of the heat-generating portion of the heating coil can be switched by a switch, and power can be saved. In addition, the electromagnetic induction heating method generally has high heating efficiency, can shorten the warm-up time, and can perform a quick start. Further, by using the litz wire, it is possible to provide a heat fixing device in which the deterioration of insulation properties at a high temperature is suppressed and the reliability is greatly improved.

[0012]

According to the present invention, it is possible to obtain an electromagnetic induction heating coil which has a high heating efficiency, can shorten a warm-up time, can cope with a quick start, and can save power.
As a result, a power-saving heating fixing device can be obtained. The practical effect is large.

[Brief description of the drawings]

FIG. 1 is a simple explanatory view showing an embodiment of the present invention.
(a) is a simplified front view of the electromagnetic induction heating coil, (b), (c)
3 is a circuit diagram showing a connection example of an electromagnetic induction heating coil.

FIG. 2 is a perspective view illustrating a configuration of a heat fixing device.

FIG. 3 is an explanatory diagram showing a configuration of a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromagnetic induction heating coil 2 Recording material 3 Heating roller 4 Halogen lamp 5 Pressure roller 6 Heating fixing device 7 Coil bobbin 8 Heating nip 9 Power supply circuit M1, M2, M3 Split coil W Paper passing range

Claims (1)

[Claims] 1. An electromagnetic induction heating coil, which is wound and disposed in a longitudinal direction in a heating roller constituting a heat fixing device, wherein the electromagnetic induction heating coil 1 includes a split coil M2 and a split coil M2. In addition to the split coils M1 and M3 located on both sides, the heating range of the heating roller is
An electromagnetic induction heating coil which is connected to a power supply circuit 9 via a switch SW1 (SW2) so as to be switched between when M2 is used alone and when divided coils M1, M2 and M3 are connected in series.