JP3773032B2 - Heating method of heating roller - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a heating method for a heating roller disposed in an image forming apparatus such as a copying machine, and more particularly to a heating roller heating method suitable for an electromagnetic induction heating type fixing device. is there.
[0002]
[Prior art]
An image forming apparatus such as a copying machine or a printer is provided with a heat fixing device for image formation, and a recording material (transfer) by an appropriate image forming unit such as an electrophotographic process, an electrostatic recording process, or a magnetic recording process. A sheet of paper, electrostatic recording paper, electrofax paper, printing paper, etc.) is formed and supported by a transfer or direct method, and an unfixed image (toner image) corresponding to the desired image information is heated on the surface of the recording material Thus, the image is fixed as a permanent image.
[0003]
As a heat fixing device having such a structure, for example, as shown in FIG. 4, a device using a halogen heater 8 inserted inside the heating roller 1A is often used. In this heat fixing device, when the halogen heater 8 generates heat and emits light, the heat is radiated and the heating roller 1A is heated by convection, and the heating roller 1A records the entire heating roller 1A with a uniform temperature distribution by heat conduction. It functions to fix the permanent image on the surface of the paper 9.
However, when the size of the recording paper 9 changes and the paper passing range W with respect to the heating roller 1A changes from W1 to W2 as shown in FIG. 2, the temperature of the non-paper passing portion (W1-W2) is abnormal. However, there is a problem that the image quality deteriorates. Therefore, in order to solve this problem, at least two halogen heaters 8 having different lengths are provided, and a measure for changing the temperature distribution of the heating roller 1A depending on the size of the recording paper 9 has been taken.
[0004]
[Problems to be solved by the invention]
However, in the heat-fixing apparatus using the halogen heater 8, it is difficult to cope with the power saving that is recently required because the time until the entire heating roller 1A has a uniform temperature distribution, that is, the so-called warm-up time is long. In addition, there was a difficulty in responding to the quick start.
Further, in the standby state in which the image forming apparatus stops the printing operation, there is a difficulty in requiring a complicated operation of adjusting the temperature of the heat fixing device to the standby temperature corresponding to the standby state.
[0005]
Therefore, an object of the present invention is to configure the heat fixing device using an electromagnetic induction heating coil with high heating efficiency, to shorten the warm-up time and enable quick start, and to increase the heating width for the heating roller depending on the recording paper size. It is an object of the present invention to provide a heating method of a heating roller that can save power by changing.
[0006]
[Means for Solving the Problems]
In a first aspect, the present invention is arranged in the image forming apparatus and the heating roller 1 constituting the heating and fixing apparatus is different in the direction of magnetic flux by 90 degrees from each other and in the axial direction of the heating roller in the state wound around the coil bobbin. arranged to have two different electromagnetic induction heating coil 2 in length, the heating roller 1 in either the electromagnetic induction heating coil 2 in accordance with the sheet passing range of the recording paper passing through the pre-Symbol heating roller 1 and heated to a heating method of the heating roller can be suppressed excessive temperature rise of Hitsushi portion, said electromagnetic induction heating coil 2 is heated roller 1 through the coil bobbin 5 of the cross-sectional shape substantially I-shaped The electromagnetic induction heating coil 3 is heated via a cylindrical coil bobbin 5A disposed so as to include a circumferential outer periphery with the longitudinal direction of the electromagnetic induction heating coil 2 as an axis. Low Provides a method of heating a heating roller, characterized in that the winding in one of the circumferential direction.
According to the first aspect, since the heating method of the heating roller of the present invention is electromagnetic induction heating, the heating efficiency is high, the warm-up time is shortened, and a quick start is possible.
In addition, the two electromagnetic induction heating coils 2 and the electromagnetic induction heating coils 3 having different lengths in the axial direction of the heating roller in a state of being wound around the coil bobbin are arranged so that the magnetic flux directions are different from each other by 90 degrees without being juxtaposed. Therefore, it is possible to save power by changing the heating width for the heating roller 1 according to the recording paper size.
[0007]
In a second aspect, the present invention is arranged in the image forming apparatus so that the magnetic flux directions in the heating roller 1 constituting the heat fixing apparatus are different from each other by 90 degrees and in the axial direction of the heating roller in a state wound around the coil bobbin. Two electromagnetic induction heating coils 2 and 3 having different lengths are provided, and the heating roller 1 is set to one of the electromagnetic induction heating coils 2 and 3 according to the sheet passing range of the recording paper passing through the heating roller 1. A heating roller heating method capable of suppressing an excessive temperature rise in a non-sheet passing portion by heating, wherein the electromagnetic induction heating coil 2 is formed between a cylindrical (cylindrical) intermediate portion 5C and both ends of the intermediate portion 5C. Winding in the circumferential direction of the heating roller 1 around an intermediate part 5C of a coil bobbin 5B composed of extension parts 5D and 5D having a substantially I-shaped cross section, and the electromagnetic induction heating coil 3 is extended parts 5D and 5D of the coil bobbin 5B. Through Provides a method of heating a heating roller, characterized in that the winding in the longitudinal direction of the electromagnetic induction heating portion overlaps as heating roller 1 of the coil 2 Te.
According to the second aspect, the electromagnetic induction heating coil 2 and the electromagnetic induction heating coil 3 can be wound around one coil bobbin 5B, and the heating roller can be downsized.
[0008]
In a third aspect, the present invention provides a heating roller heating method according to claim 1 or 2, wherein the coil bobbins 5 and 5B are provided with a ferrite core 4 made of one or a plurality of small pieces. .
According to the third aspect, the ferrite core 4 can be shared by the electromagnetic induction heating coils 2 and 3 to reduce the cost of the heat fixing device, and the magnetic flux efficiency by the electromagnetic induction heating coils 2 and 3 can be increased. Can do.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings. Note that the present invention is not limited thereby.
[0011]
-First embodiment-
FIG. 1 is an explanatory view showing a first embodiment of the present invention, wherein FIG. 1 (a) is a partial sectional front view showing the configuration of the heating roller, FIG. 1 (b) is a side view of the heating roller, and FIG. (c) is a sectional view taken along line XX of FIG.
In the figure, reference numeral 1 denotes a heating roller. Although not shown in detail, a magnetic conductive layer having a thickness of 0.1 mm to 2 mm formed of ferromagnetic and conductive iron or SUS430 is provided outside the magnetic conductive layer. The structure includes a release layer 4 (10 μm to 50 μm is preferable) made of a formed fluorine-based heat-resistant resin and having a thickness of 20 μm that facilitates peeling of the recording material.
Reference numerals 2 and 3 are electromagnetic induction heating coils each formed by winding an insulated wire, and the electromagnetic induction heating coil 2 is heated via a coil bobbin 5 having a substantially I-shaped cross section (the same applies to H-shaped and E-shaped). Winding in the longitudinal direction of the roller 1, the electromagnetic induction heating coil 3 is wound in the circumferential direction of the heating roller 1 via a cylindrical coil bobbin 5 A disposed outside the coil bobbin 5.
The coil bobbin 5 preferably has one or more nickel-based or manganese-based ferrite cores 4 mounted therein.
The electromagnetic induction heating coil 2 is wound with a length substantially the same as the width of the heating roller 1, and the electromagnetic induction heating coil 3 is wound with a shorter length than the electromagnetic induction heating coil 2. The electromagnetic induction heating coil 2 has a recording paper size. Corresponding to the side of A4, the electromagnetic induction heating coil 3 is set to correspond to the length of the recording paper size A4. Specifically, the A4 horizontal electromagnetic induction heating coil 2 has a coil length of 300 mm to 340 mm, and the A4 vertical electromagnetic induction heating coil 3 has a coil length of 200 mm to 240 mm.
Needless to say, the electromagnetic induction heating coil 2 may be wound in the recording paper size A4 lengthwise, and the electromagnetic induction heating coil 3 may be wound in the recording paper size A4 width.
In addition, the electromagnetic induction heating coils 2 and 3 are composed of litz wires, etc., with 10 to 400 twisted heat-resistant urethane wires with a wire diameter of 0.1 mm to 0.5 mm, which can lower the heat resistance temperature of the insulated wires themselves. it can.
Needless to say, insulated electromagnetic wires such as polyamide-imide copper wire and polyester-imide copper wire may be used for the electromagnetic induction heating coils 2 and 3.
[0012]
-Second Embodiment-
FIG. 3 is an explanatory view showing a second embodiment of the present invention, wherein FIG. 3 (a) is a partial sectional front view showing the configuration of the heating roller, FIG. 3 (b) is a side view of the heating roller, and FIG. (c) is a sectional view taken along line XX of FIG.
In the figure, the same components as those in the first embodiment are denoted by the same symbols, and the description thereof is omitted here.
A feature of the second embodiment is that the electromagnetic induction heating coils 2 and 3 are wound around the same coil bobbin 5B formed by integrally molding or combining a plurality of coil bobbins, and the coil bobbin 5B is a cylindrical intermediate portion. 5C and the extension part 5D and 5D of the cross-sectional shape substantially I-shape arrange | positioned at the both ends of the intermediate part 5C are comprised.
Specifically, the electromagnetic induction heating coil 2 is wound around the intermediate portion 5C of the coil bobbin 5B in the circumferential direction of the heating roller 1, and the electromagnetic induction heating coil 3 is heated via the extensions 5D and 5D of the coil bobbin 5B. Is wound so as to overlap a part of the electromagnetic induction heating coil 2, and the heating roller 1 can be reduced in size by such a configuration.
It goes without saying that the electromagnetic induction heating coil 2 can be wound in the circumferential direction on the outer periphery of the intermediate portion 5C after the electromagnetic induction heating coil 3 is wound around the coil bobbin 5B having a flat surface on the intermediate portion 5C. Nor.
The electromagnetic induction heating coil 3 is wound to a length corresponding to the recording paper size A4, and the electromagnetic induction heating coil 2 is wound to a length corresponding to the recording paper size A4.
Further, although not shown, it is desirable to install a nickel-based or manganese-based ferrite core inside the coil bobbin 5B.
[0013]
In the heating method of the heating roller using the electromagnetic induction heating coils 2 and 3 having such a configuration, the directions of magnetic fluxes generated from the electromagnetic induction heating coils 2 and 3 are different from each other by 90 degrees. Can be wound on the cylindrical coil bobbin in the same direction in multiple layers, or can be almost eliminated from the mutual induction that occurs when the coil bobbin is wound in the same direction and juxtaposed in the heating roller.
As a result, even when the size of the recording paper 9 changes, as shown in FIG. 2, the temperature distribution of the paper passing portions W1 and W2 of the heating roller 1 becomes uniform, and the non-paper passing portion (W1-W2) is abnormal. Therefore, it is possible to provide a practical and efficient heating and fixing device because there is no significant temperature rise.
[0014]
A specific adverse effect is caused by an abnormal waveform with respect to a resonance current caused by an influence of an induction current on a resonance circuit including a resonance capacitor or a switching element that supplies current to the electromagnetic induction heating coils 2 and 3 to generate heat. There is a beeping sound and abnormal heating.
[0015]
【The invention's effect】
The heating method of the heating roller according to the present invention is electromagnetic induction heating, which has high heating efficiency, shortens the warm-up time, and enables quick start. In addition, since the heating range of the heating roller can be changed depending on the recording paper size, an excessive temperature rise in the non-sheet passing portion can be prevented, power saving can be achieved, and a heat fixing device excellent in image quality can be provided. The practical effect is great.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a first embodiment of the present invention, in which FIG. 1 (a) is a partial sectional front view showing a configuration of a heating roller, FIG. 1 (b) is a side view of the heating roller, and FIG. (c) is a sectional view taken along line XX of FIG.
FIG. 2 is an explanatory diagram showing a temperature distribution of a heating roller according to the present invention.
FIG. 3 is an explanatory view showing a second embodiment of the present invention, wherein FIG. 3 (a) is a partial sectional front view showing the configuration of the heating roller, FIG. 3 (b) is a side view of the heating roller, and FIG. FIG. (C) is a cross-sectional view taken along line XX of FIG.
FIG. 4 is a perspective view showing a schematic configuration of a conventional heat fixing apparatus.
[Explanation of symbols]
1,1A heating roller
2,3 Electromagnetic induction heating coil 4 Ferrite core
5,5A, 5B Coil bobbin 7 Pressure roller 8 Halogen heater 9 Recording paper T Temperature
W, W1, W2 Paper feeding range

Claims (3)

Two electromagnetic induction heatings in which the magnetic flux directions are different from each other by 90 degrees in the heating roller 1 constituting the heat fixing device disposed in the image forming apparatus, and the lengths in the axial direction of the heating roller when wound around the coil bobbin are different. the coil 2 is disposed to heat the heating roller 1 in either the electromagnetic induction heating coil 2 in accordance with the sheet passing range of the recording paper passing through the pre-Symbol heating roller 1, Hitsushi portion A heating roller heating method that can suppress an excessive temperature rise of
The electromagnetic induction heating coil 2 is wound in the longitudinal direction of the heating roller 1 via a coil bobbin 5 having a substantially I-shaped cross section,
The electromagnetic induction heating coil 3 is wound in the circumferential direction of the heating roller 1 via a cylindrical coil bobbin 5A disposed so as to include a circumferential outer periphery with the longitudinal direction of the electromagnetic induction heating coil 2 as an axis. A heating method of a heating roller, characterized by being drawn. Two electromagnetic induction heatings in which the magnetic flux directions are different from each other by 90 degrees in the heating roller 1 constituting the heat fixing device disposed in the image forming apparatus, and the lengths in the axial direction of the heating roller when wound around the coil bobbin are different. Coils 2 and 3 are arranged, and either one of the electromagnetic induction heating coils 2 and 3 is heated in accordance with the sheet passing range of the recording paper passing through the heating roller 1 to A heating roller heating method capable of suppressing an excessive temperature rise,
  The electromagnetic induction heating coil 2 has a circular (cylindrical) intermediate portion 5C and an intermediate portion 5C of a coil bobbin 5B composed of substantially I-shaped extensions 5D and 5D at both ends of the intermediate portion 5C. Winding in the circumferential direction,
  The electromagnetic induction heating coil 3 is connected to an extension 5D of the coil bobbin 5B. , A heating method for a heating roller, wherein the heating roller 1 is wound in the longitudinal direction so as to overlap a part of the electromagnetic induction heating coil 2 via 5D. The heating method for a heating roller according to claim 1 or 2, wherein the coil bobbins (5, 5B) are provided with a ferrite core (4) made of one or a plurality of small pieces.

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