JPH10106719A - Heater roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater roller by a method wherein a plurality of feeder rings are formed on the same end side of the heater roller so as not to produce short-circuiting between exothermic resistors connected to the plurality of the feeder rings. SOLUTION: In this heater roller, two or more exothermic resistors are laminated on an insulation film 12 formed on an outside surface of a metallic base material 11. Two or more feeder rings 2a and 2b are provided to be individually connected to the same end side of the respective exothermic resistors. Each of the exothermic resistors is provided with electrodes 132a and 132b, relay parts 13aa and 13bb, and an exothermic part. The relay part 13aa covered with an insulative member Z is continued to at least the electrode 132a other than the inside electrode 132b on the same end side of electrodes 132a and 132b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heating roller,
More specifically, it is used as a heating roller of a heat roller type heat fixing device used for fixing a toner image in an electrophotographic copying machine, a laser printer, a facsimile, etc., a heating roller of a sheet body surface covering device, and a heater of various other heating devices. Heating roller.

[0002]

2. Description of the Related Art In an electrophotographic copying machine or the like, as a method for heating and fixing a toner image formed on a recording material, conventionally, a method has been proposed in which a heating roller and a pressure roller disposed in contact with the heating roller are fixed. A heat roller method for fixing the unfixed toner image on the recording material by passing the recording material on which a toner image including an unfixed toner image is formed is widely known. In recent years, Japanese Patent Application Laid-Open No. 56-109381
JP-A-63-182684, JP-A-6-1868
No. 77, a heating roller having a self-heating function is used.

In such a heating roller having a self-heating function, an insulating film is formed on a surface of a cylindrical metal base material, and a heating resistor is laminated on the insulating film. Further, according to the width of the paper passing through the heating roller, the heating resistor is divided into a plurality of heating elements in order to change the heating area of the heating roller, the electrode consisting of a part of each heating resistor, the metal base material Each of the attached power supply rings is electrically connected.

With reference to FIG. 3, a description will be given of a heating resistor divided into two parts out of the plurality of heating resistors described above. The heat generating resistor 13 includes a first heat generating resistor 13A and a second heat generating resistor 13B for changing a heat generating region depending on a sheet passing width as shown in a P area and a Q area, and includes two heat generating resistors 13A. One electrode of the electrode 13B is common to the electrode 131, and the other electrode is provided independently like the electrode 132a and the electrode 132b. The first heating resistor 13A is connected to the electrode 132a at the relay section 13aa and the heating section 13a that mainly generates heat, and the second heating resistor 13B is connected to the electrode 132b at the relay section 13bb and the heating section 13b that mainly generates heat. linked. As described above, the electrode of the heating resistor 13 is connected to the common electrode 1 at one end of the heating roller.
The outer electrode 132a and the inner electrode 132b are arranged close to each other on the other end side.

[0005] The electrode 132a, the relay section 13aa, and the heating section 1
3a and the electrode 131 are connected to the first heating resistor 13 for explanation.
Although described with a different name from A, all are manufactured integrally with the first heating resistor 13A using the same member. Similarly,
The electrode 132b, the heating section 13b, and the relay section 13bb
The heating resistor 13B and the same member are integrally manufactured.
The first heating resistor 13A has another relay portion connected to the electrode 131, but is not shown here with a reference numeral. Further, the first heating resistor 13A and the second heating resistor 13B are integrally manufactured by the same member.

The electrode of the heating resistor is wound around the metal substrate at the end of the metal substrate. As shown in FIG. 7A, the relay section 13aa of the first heating resistor 13A is connected to the metal substrate. The electrode 132a extends in the axial direction on the formed insulating film, and is formed so as to surround substantially the entire circumference of the metal base material. The electrode 132b of the second heating resistor 13B is also formed to be inside the electrode 132a and surround the outer periphery of the metal base. That is, the first heating resistor 13
A of the relay section 13aa of the second heating resistor 13B
32b. And FIG.
As shown in (b), the electrode 132a and the electrode 132b are electrically connected to separate power supply rings 2a and 2b on the inner peripheral surface.

[0007]

However, in order to cause only the first heating resistor 13A to generate heat, the power supply ring 2 is required.
When a current is passed through a, the relay 13aa and the electrode 132b
However, since the short-circuit is caused by the power supply ring 2b, a current also flows through the second heating resistor 13B, and the second heating resistor 13B also generates heat. Therefore, there is a problem that the heat generation area cannot be switched according to the sheet passing width.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric power supply system in which a plurality of power supply rings are formed on the same end of a heating roller. It is an object of the present invention to provide a heating roller that does not short-circuit each of the heating resistors that are electrically connected.

[0009]

In order to solve the above-mentioned problems, a heating roller according to the first aspect of the present invention comprises two or more heating rollers on an insulating film formed on an outer surface of a substantially cylindrical metal base material. Heating resistors are laminated, an insulating protective film is coated on the surfaces of the heating resistors, and each heating resistor is individually connected to each heating resistor at least on the same end side. A heating roller having at least one power supply ring, wherein each of the heating resistors includes an electrode formed so as to surround substantially the entire circumference of the metal base, a heating section that mainly generates heat, and the electrode and the heating section. A relay section extending along the axial direction connecting the
At least the respective electrodes on the same end side of each of the heating resistors are arranged so as to be axially shifted at one end of the metal base material,
It is electrically connected to the inner peripheral surface of the power supply ring, and among the electrodes, at least each relay portion following the electrode other than the inside of the metal base in the axial direction is covered with an insulating member. Features.

[0010] In order to solve the above problem, a heating roller according to claim 2 is the heating roller according to claim 1, and in particular, the insulating member is a polyimide film. .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heating roller according to the present invention will be described. FIG. 1 is a partially cutaway front view showing a specific configuration of a heating roller of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. The heating roller 10 includes a substantially cylindrical metal base material 11,
The insulating film 12 formed on the outer surface of the metal base 11
A heating resistor 13 formed on the insulating film 12;
A protection film 14 provided to cover the heating resistor 13, a release layer 15 formed on the protection film 14,
A power supply ring 2 for flowing a current through the heating resistor 13;
2a and 2b.

The cylindrical substrate 11 is a cylindrical member having an outer diameter of 20 mm, a thickness of 1.5 mm, and a total length of 304 mm. The metal substrate 11 may be made of a metal material having a large thermal conductivity, particularly a metal material having a thermal conductivity of 100 W / (m · K) or more from the viewpoint of preventing temperature unevenness on the surface of the heating roller 10. Preferably, specifically, it is preferable to be made of an aluminum alloy. By using an aluminum alloy as the metal substrate, the surface temperature of the heating roller 10 can be made more uniform.

The insulating film 12 formed on the metal substrate 11 is made of an insulator containing alumina or silica as a main component. Here, the thickness of the insulating film 12 is 50 to 100 μm.
m, and in this embodiment, the thickness is about 70 μm.
Of alumina.

The heating resistor 13 is the same as that shown in FIG. 3, contains silver as a conductive material, and has a width of 0.5 mm to
It is 3 mm in thickness and about 10 μm in thickness. In the present invention, a silver-palladium (Ag-Pd) alloy is used as a material constituting the heating resistor 13. Heating resistor 13
Although there is no particular limitation on the method for forming
The screen printing method is preferable because a heating resistor having a thickness of about 20 μm can be easily formed. Although the heating resistor 13 shown in FIG. 3 has a common electrode 131 formed on one end side, this is connected to the first heating resistor 13 as shown in FIG.
A single electrode 131a of A and single electrode 131b of second heating resistor 13B may be provided.

The protective film 14 is a film having a thickness of 50 μm and made of an insulator containing alumina or silica as a main component. The protective film 14 prevents deterioration of the heating resistor pattern 13, secures electrical insulation, and protects the heating resistor pattern 13 from foreign matter. It is provided from the viewpoint of damage prevention. As the thickness of the protective film 14,
Usually 100 μm or less, preferably 50 to 80 μm
It is said. If the thickness of the protective film exceeds 100 μm, it becomes difficult for heat to be transmitted to the outer surface of the heating roller 10,
Heating performance may be adversely affected.

The release layer 15 is a fluororesin layer provided for improving the releasability on the surface of the heating roller 10. By providing the release layer 15, an offset phenomenon is less likely to occur during the fixing operation, and good fixing performance can be obtained.

The power supply rings 2, 2a and 2b are ring-shaped members made of a copper alloy, and are provided with the heat generating resistors 13 shown in FIG.
Are electrically connected to the electrodes 131, 132a, and 132b on the inner peripheral surface thereof. That is, two power supply rings 2 a and 2 b are individually connected to the electrodes 132 a and 132 b of the heating resistor 13 at one end of the heating roller.
When the heating resistor shown in FIG. 4 is used, two power supply rings are individually provided on both ends of the heating roller, though not shown.

To prevent short-circuiting of each heating resistor electrically connected to the plurality of power supply rings, specifically,
An example in which an insulating member is used so that the 3aa and the electrode 132b are not short-circuited by the power supply ring 2b, and an example in which a polyimide film is used will be described. First, an example using an insulating member will be described. The power supply rings 2, 2 a, and 2 b are connected to their inner peripheral surfaces and electrodes 131, 13 by a conductive adhesive.
2a and 132b are connected and fixed. As shown in FIG. 5A, the relay portion 13aa of the first heating resistor 13A, which is formed on one end of the heating roller and crosses between the ends of the electrode 132b of the second heating resistor 13B, is electrically insulated. Coated with member Z. Then, as shown in FIG. 5 (b), the power supply rings 2a and 2b are connected to the electrodes 132a and 1b by a conductive adhesive.
32b. Note that the insulating member Z may be formed by extending a part of the protective film 14 that covers the heating resistor 13 described above.

That is, the power supply ring 2 is formed by the insulating member Z.
b is insulated from the inner peripheral surface and the relay portion 13aa, so that when the current flows through the power supply ring 2a, the relay portion 13aa and the electrode 1aa are insulated.
32b is not short-circuited by the power supply ring 2b.
Similarly, when a current flows through the power supply ring 2b, the relay unit 13aa
And the electrode 132b is not short-circuited by the power supply ring 2b. Therefore, the switching of the heat generation area according to the sheet passing width can be reliably performed.

Next, an example using a polyimide film will be described. At room temperature, the outer diameter of a portion composed of the metal substrate 11, the insulating film 12 formed on the outer surface thereof, and the electrodes 132a and 132b laminated on the insulating film 12 (hereinafter, the outer diameter of the power supply ring mounting portion) ) Are larger than the inner diameters of the power supply rings 2a and 2b. Then, by heating the power supply rings 2a and 2b, the inner diameter thereof is made larger than the outer diameter of the power supply ring attachment portion, and the power supply rings 2a and 2b are fitted to the power supply ring attachment portion. Thereafter, the power supply rings 2a and 2b are cooled,
The electrodes 131, 132a, and 132b are in direct contact with the respective inner peripheral surfaces, and the power supply rings 2a and 2b are fixed.

Before attaching the power supply rings 2a and 2b,
As shown in FIG. 6A, the relay portion 13aa formed on one end of the heating roller is covered with the polyimide film F. Then, as shown in FIG. 6B, the power supply rings 2a and 2b are
a and 132b are directly contacted and fixed. By using the polyimide film F in this way, compared to the case of using the insulating member Z described above, since the film is a film, the handling becomes easier, and as a result, the effect of simplifying the production is obtained. Occurs. That is, the inner peripheral surface of the power supply ring 2b and the relay portion 13aa are formed by the polyimide film F.
Are insulated from each other, so that when the current flows through the power supply ring 2a, the relay section 13aa and the electrode 132b are not short-circuited by the power supply ring 2b. Therefore, the switching of the heat generation area according to the sheet passing width can be reliably performed.

In this embodiment, the connection example between the power supply ring and the heating resistor uses an insulating member which is a part of the protective film when a conductive adhesive is used, and uses a shrink-fitting technique. In this case, a polyimide film was used. However, a polyimide film may be used even when a conductive adhesive is used, or an insulating member may be used when a shrink fit technique is used.

[0023]

According to the present invention, at least one end of the heating roller is provided with two or more power supply rings individually connected to the respective electrodes of the plurality of heating resistors, and formed at one end thereof. Of the respective electrodes, at least each relay portion following the electrode other than the inner side is covered with an insulating member, so that a plurality of heating resistors are not short-circuited by the power supply ring formed at one end side. . In addition, when the power supply ring is attached to the metal substrate using shrink fit technology, the use of a polyimide film instead of the insulating member maintains insulation and simplifies handling and simplifies manufacturing. Has an effect.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing an example of a heating roller of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a developed schematic view of a heating resistor constituting a heating roller.

FIG. 4 is another developed schematic view of the heating resistor constituting the heating roller.

FIG. 5 is an explanatory diagram showing a connection state between a heating resistor, a power supply ring, and a state where a relay portion of the heating resistor is covered with an insulating member.

FIG. 6 is an explanatory diagram showing a connection state between a heating resistor, a power supply ring, and a state in which a relay film of a heating resistor is covered with a polyimide film.

FIG. 7 is an explanatory diagram showing a connection state with a conventional heating resistor power supply ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Metal base material 12 Insulating film 13 Heating resistor 13A 1st heating resistor 13B 2nd heating resistor 13a Heating portion 13b Heating portion 13aa Relay portion 13bb Relay portion 132a Electrode 132b Electrode 14 Protective film 15 Release layer Z insulation Functional member F Polyimide film 2 Power supply ring 2a Power supply ring 2b Power supply ring

Claims (2)

[Claims] 1. An insulating film formed on an outer surface of a substantially cylindrical metal substrate, two or more heating resistors are laminated, and an insulating protective film is provided on the surface of the heating resistors. A heating roller that is covered and has two or more power supply rings individually connected to each of the heating resistors on at least the same end side of each of the heating resistors, wherein each of the heating resistors is made of metal. An electrode formed so as to surround substantially the entire circumference of the base material, a heating section mainly generating heat, and a relay section extending along an axial direction connecting the electrode and the heating section, and each of the heating resistors At least each electrode on the same end side is arranged to be shifted in the axial direction at one end of the metal base material,
It is electrically connected to the inner peripheral surface of the power supply ring, and among the electrodes, at least each relay portion following an electrode other than the inside of the metal base in the axial direction is covered with an insulating member. Characteristic heating roller. 2. The heating roller according to claim 1, wherein the insulating member is a polyimide film.