JPH10288905A - Self-heat generating type heat roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a space where a bearing part to freely rotatably support a heating roller to the casing of a fixing device and a driving gear part fixed on the outer peripheral surface of the heating roller and receiving the transmission of driving force are provided. SOLUTION: This heat roller performs fixing by making an exorthermic resistor layer 5 integrated with a hollow cylindrical core material 2 or the inner surface of the core material 2 generate heat. In this case, power is supplied to a heat self-generating type heat roller by pressing a power supply brush 21 to a power supply cap 10 arranged at the end part of the core material 2 or the hollow inside of the core material 2, so that the power supply brush 21 is held so as to move back and forth in an axial direction by a power supply brush holder 20 constituted of a nonconductive resin. Then, the power supply brush holder demonstrates a thrust stopping function to control the movement of the core material in the axial direction by bringing the power supply brush into press-contact with the power supply brush 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a fixing device used in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile machine, etc. The present invention relates to a fixing device having a self-heating type heating roller having a heating resistor layer on the inner surface of a core material or a core material.

[0002]

2. Description of the Related Art In recent years, electrophotographic copying machines, printers,
2. Description of the Related Art Energy saving is demanded in image forming apparatuses such as facsimile machines, and as one of methods for promoting energy saving, energy saving is performed in a fixing device, which is a unit that consumes the most electric energy. Under these circumstances, a fixing device employing a fixing method using a self-heating type heating roller has been proposed. Unlike the conventional type that uses a special heat source such as a halogen heater, this heating roller is a self-heating type in which the core material of the roller itself or a heating resistor formed on the core material generates heat. In comparison with this, there is an advantage that the thermal efficiency is good and a quick start can be achieved. The configuration of these self-heating type heating rollers includes a method in which a heating resistor is arranged along the outer surface of a hollow cylindrical core material, and a heating resistor having a configuration in which the core material itself blends a conductor with ceramic. Or a method in which a heating resistor is formed on the inner surface of the core material.
It is roughly divided into two. In any of these methods, it is necessary to reduce the heat capacity of the core material as much as possible in order to quickly raise the temperature to the fixing temperature. Therefore, it is important to reduce the thickness of the core material. However, not only the method using the self-heating type heating roller but also the conventional method using a halogen lamp, the heating roller using a thin core material continuously feeds a narrow sheet of paper. In this case, only the temperature of the non-sheet passing portion located at the outer end in the width direction is excessively increased, and when a wide sheet is passed in this state, a defect such as a fixing failure occurs at the end of the roller which is in an overheated state. It was easy. If a non-heat-generating region having a fixed width is formed on the end portion in the width direction of the heating roller in order to prevent this problem, when the heater is started, a problem such as the temperature of the end portion used for fixing does not rise completely occurs. . In order to minimize such phenomena such as insufficient temperature rise in the edge temperature, the difference between the axial length of the heating roller and the heat generation width should be as small as possible, and the maximum paper passing width and the heating roller length should be as close as possible. In practice, it is effective to use a bearing part for rotatably supporting the heating roller with respect to the casing of the fixing device, or a driving part fixed to the outer peripheral surface of the heating roller and receiving the driving force. A gear portion and a C-ring attachment portion for stopping the thrust, which is disposed outside the driving gear portion in the axial direction, are required, and there is a limit to shortening the length of the heating roller so as to approach the paper width.

[0003] Next, as a method of supplying power to the core material constituting the self-heating type heating roller or the heating resistor formed on the core material, an outer peripheral surface of the core material in the axial direction is provided over the entire circumference in the circumferential direction. It is known to provide a ring-shaped power supply portion extending across the power supply portion and apply the power supply brush from the circumferential direction of the power supply portion. However, in this method, it is necessary to arrange the power supply ring outside the paper passing width. Therefore, the length of the heating roller in the axial direction is further increased by the space in which the power supply ring is disposed. As a conventional technique to solve this problem, a power supply unit is provided at the edge of the heating roller,
There has been proposed a power supply unit in which power is supplied by pressing a power supply terminal from an axial direction. According to this power supply method, there is no need to provide a space for installing the power supply ring on the outer peripheral surface of the heating roller. Therefore, there is no possibility that the length of the heating roller becomes unnecessarily long for power supply. However, in this type, when the C-ring for receiving the thrust load is omitted and the roller is shortened, the power supply unit provided at the edge of the heating roller and the power supply unit provided at the edge of the heating roller due to a shift in the axial position of the heating roller are used. There is a possibility that a power supply failure state may occur due to separation of a power supply terminal to be in contact with the power supply unit. In other words, even though the C-ring is easily omitted and the thrust is stopped only by the power supply terminal because the power supply terminal is pressed against the power supply portions provided at both ends of the heating roller, the conventional power supply Depending on the engagement structure between the terminal and the power supply unit, the thrust stop function of the power supply terminal cannot be sufficiently exhibited, and there is a possibility that the power supply unit and the power supply terminal may be separated. In order to prevent this problem, if the pressing force from the power supply terminal to the power supply unit is increased to have a strong thrust stop function, the thrust stop always comes into strong contact with the rotating body. There was an adverse effect such as faster abrasion and increased driving load.

[0004]

The problem to be solved by the present invention is to solve the above-mentioned problem in the prior art with a simple configuration without increasing the cost.
That is, an object of the present invention is to provide a bearing portion for rotatably supporting a heating roller with respect to a casing of a fixing device and a driving gear portion fixed to an outer peripheral surface of the heating roller and receiving a driving force. While securing space for
Further, while omitting the C-ring for stopping thrust disposed axially outside the driving gear portion, the axial direction of the heating roller is minimized in order to minimize the phenomenon of insufficient temperature rise at the end of the heating roller. An object of the present invention is to make the difference between the length and the heat generation width as small as possible, and to make the maximum paper passing width and the heating roller length as close as possible. Other issues are:
An object of the present invention is to enable good power supply without increasing the axial length of a heating roller, increasing wear of a power supply terminal, and increasing a driving load.

[0005]

In order to solve the above-mentioned problems,
According to a first aspect of the present invention, there is provided a self-heating type heating roller for fixing by making a hollow cylindrical core material or a heating resistor layer integrated with the inner surface of the core material heat, wherein power is supplied to the self-heating type heating roller. Is carried out by pressing the power supply brush against the power supply cap disposed at the end of the core material or the hollow inside of the core material, and the power supply brush can be advanced and retracted in the axial direction by the power supply brush holder made of a non-conductive resin. And the power supply brush holder exerts a thrust stop function of restricting the axial movement of the core material by pressing the power supply brush against the power supply cap. In the invention according to claim 2, the power supply brush is elastically urged in a protruding direction by a spring provided in the power supply brush holder, and even when the core material moves a maximum distance in the axial direction, the power supply brush and the power supply cap The contact state is maintained. The invention according to claim 3 is characterized in that the contact between the power supply brush holder and the end of the core material is performed via a member (power supply cap holder, drive gear) fixed to the core material. The invention according to claim 4 is characterized in that, of the member fixed to the core member, a surface facing the power supply brush holder is a flat surface over the entire circumference in the circumferential direction. The invention of claim 5 is characterized in that the surface of the power supply brush holder facing the member fixed to the core material is a flat surface over the entire circumference in the circumferential direction.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments shown in the drawings. FIG. 1 is a cross-sectional view showing a self-heating type heating roller according to an embodiment of the present invention, and FIGS. FIG. 2 is a cross-sectional view of the heating roller 1. The heating roller 1 has PFA or P
A release layer 3 made of TFA or the like is provided along a predetermined axial length over the entire circumference, and an insulating layer 4 made of ceramics or a non-conductive resin is further provided on the entire circumference of the inner surface of the core material 2. Silver alloy,
Alternatively, it has a configuration in which heating resistors 5 made of carbon fiber or the like are sequentially laminated. The length of the heating resistor 5 in the axial direction is shorter than that of the core 2, and the positions of both ends of the heating resistor 5 are axially inner than the positions of both ends of the core 2. A conductive tape 6 for protecting the heating resistor is attached from both ends of the heating resistor 5 to the insulating layer 4, and a conductive power supply cap 10 is fitted to the inner periphery of the conductive tape 6. Installed. This power supply cap 10
Are also arranged on the inner side by a predetermined length from both ends of the core material 2. A power supply cap holder (a member fixed to a core material) 11 made of a non-conductive resin is fitted and fixed to the inner surface of the power supply cap 10 from the outside in the axial direction.
The power supply cap 10 is reinforced.

Incidentally, in the example shown in FIG.
The insulating layer 4 is provided on the inner surface of the substrate. However, if the core material itself is made of a non-conductive material, for example, glass or ceramics, the insulating layer 4 becomes unnecessary. In addition, the conductive tape 6 for protection is provided at the end of the heating resistor 5, but this is also an example, and the power supply cap 10 is shaped so as to directly fit on the inner surface of the heating resistor 5. Is also good. Note that the heating resistor 5 and the conductive tape 6 are all on the order of microns, much thinner than the thickness of the core material and the power supply cap.
In FIG. 1, the wall thickness is intentionally exaggerated for ease of understanding. As a method of fixing the power supply cap 10 (or the power supply cap to which the holder 11 is assembled) to the core material 2, various methods can be applied, such as using a paste of a silver-based alloy as an adhesive. However, the heating roller is subjected to a heat cycle, vibration due to the entry of paper, and the like depending on the use environment, and therefore, high precision in processing is required to maintain the adhesive strength. For this reason, for example, the core material 2 is once heated to about 300 ° C. to 400 ° C., and the power supply cap 10 having a temperature of about normal temperature to about 100 ° C. is inserted and fixed to the core material within this temperature range. It is preferable to use a fast fit. At room temperature, if the inner diameter of the core portion to which the power supply cap is fixed is smaller by about 0.01 mm to 0.1 mm than the outer diameter of the power supply cap, when a temperature difference of about 200 ° C. occurs. ,
The inner diameter of the core material is increased to about 0.1 mm, the power supply cap can be easily inserted, and a reliable fixing state can be obtained when the temperature difference between the two disappears.

FIGS. 2A and 2B show an example in which a conductive power supply cap holder 11 is mounted on the power supply cap 10. FIG. 2A is an exploded perspective view, FIG. 2B is a front sectional view of FIG. FIG. 6 is a front sectional view showing a state in which the cap and the power supply cap holder are fixed, and FIG. 6D is a sectional view showing a state in which the cap and the power supply cap holder are fixed to a core material. In the actual assembling process, assembling is performed in the order of (b), (c), and (d). By fitting the power supply cap 10 and the power supply cap holder 11 to the core material in this state, The length of the portion is longer than in the case of the power supply cap alone, and erroneous mounting such as mounting the power supply cap obliquely with respect to the core material can be prevented. Further, since the abrasion powder generated when the power supply brush described below is brought into contact with the power supply cap 10 accumulates on the power supply cap holder made of a non-conductive resin, the wear powder bridges between the core material and the power supply cap. It is possible to prevent the occurrence of accidents such as leaks caused by the leakage.

The central portion (projection) 10a of the inner bottom surface of the power supply cap 10 has a protruding shape narrowed outward in the axial direction. Part of 11 (radial surface 11a)
In order to prevent contact failure due to contact with a power supply brush to be described later, as shown in FIG.
The projecting length of the central portion 10a is made equal to the thickness of the surface 11a of the power supply cap holder 11, and the end surface of the central portion 1a and the surface 11a.
It is preferable to make the center portion 10a side project axially outward from the surface 11a. This also improves the strength of the power supply cap itself, and improves the contact with the power supply brush even when the power supply cap holder is not used. In addition, a flange portion 11 b which is a protruding portion in the outer diameter direction is formed at an end of the power supply cap holder 11, and the flange portion 11 b abuts on an axial end of the core material 2, so that the power supply cap 10 is formed. It is possible to prevent excessive insertion and to suppress variation in the power supply cap mounting position.

FIG. 3A is a cross-sectional view showing the overall configuration of a fixing device having a self-heating type heating roller of the present invention, and FIG. 3B is a schematic cross-sectional view of a heating roller of a conventional fixing device. FIG. In the self-heating type heating roller of the present invention shown in FIG. 3A, a power supply terminal holder, which will be described later, is used as a thrust stopping means of the heating roller, so that it is used in the conventional example of FIG. This eliminates the need for the two retaining rings 15 and makes it possible to reduce the length of the core material of the heating roller by the space where the retaining rings are arranged. In the self-heating type heating roller, as described in the description of the related art, it is important to shorten the end, which is the non-heating portion, of the core material as much as possible in order to increase the fixing efficiency. Can be achieved effectively. The bearing 25 can be arranged in an outer region (non-heating region) deviating from the inner surface of the core material on which the heating resistor 5 is formed, and since this region is an extremely narrow region, the axial direction of the core material is reduced. You can hold down the length.

FIGS. 4 (a) and 4 (b) are cross-sectional views of a main part of the first embodiment of the present invention. The power supply cap 10 and the power supply cap holder 11, which are integrated with the core material 2 and rotate integrally, are shown. A power supply brush 21 (power supply terminal) supported by a power supply brush holder (power supply terminal holder) 20 enters into the inside of the cylinder, and is configured to slidably contact an end surface of a projection 10 a at a central portion of the power supply cap 10. Note that the heating resistor 5 and the protective conductive tape 6 are not shown in FIG. 4 and the drawings of all the following embodiments, but this is so large that these members do not appear in the drawing as described above. Actually, these members are present in the state shown in FIG. 1 and are engaged with the power supply cap and the like.

The brush holder 20 includes a large-diameter flange portion (thrust stopper portion) 20a facing the flange portion 11b of the power supply cap holder 11, and a hollow cylindrical holding portion 20b protruding from the center of the flange portion 20a. The cylindrical power supply brush 21 is fitted to the inner surface of the holding portion 20b in an aligned state and is movable in the axial direction. The power supply brush 21 is elastically urged in the protruding direction by a coil spring 22 disposed in the holding portion 20b, and is fixed to an end of the coil spring 22 to prevent the power supply brush 21 from dropping from the holding portion 20b. Have been. Fig. 4 (b)
The position indicated by a dotted line shown in FIG. When the power supply brush 21 is pressed against the protrusion 10a of the power supply cap 10, the power supply brush holder and the power supply brush realize the positioning of the core material in the thrust direction. The brush holder 20 may be fixed to any part such as a casing of the fixing device or a bracket for supporting the roller, or may be fixed to the image forming apparatus main body side. By positioning the brush holder 20 at the center of the core member 2 whose outer peripheral surface is rotatably supported by the bearing 25, the power supply brush 21 can always be stably brought into sliding contact with the projection 10a of the power supply cap 10. . A power supply 27 is connected to the power supply brush 21 via a harness 26, and a current is supplied to the heating resistor 5 via the power supply brush 21 and the power supply cap 10.

As described above, in this embodiment, the brush holder (power supply terminal holder) 20 has a certain clearance between the brush holder (power supply terminal holder) 20 and the end flange portion 11b of the power supply cap holder 11 over the entire circumference of the core member 2, and is thrust-stopped. Function. This clearance varies depending on the length of the heating roller and the material of the core material (determined by the temperature rise and the coefficient of linear expansion and adding a tolerance margin). For example, the total clearance dimension at both ends of the core material is 2 to 3 mm. That is enough. The clearance prevents the flange portion 11b of the power supply cap holder from slidingly contacting the power supply brush holder 20 when the core member rotates, thereby preventing a drive load from being generated. In addition, the axial displacement of the core material is caused by the flange portion 1 of the power supply cap holder.
1b is regulated by contact with the flange portion 20a of the power supply brush holder 20. If a retaining ring is provided as in the prior art as described with reference to FIG. 3 (b), extra space for arranging the retaining ring is required, and the axial length of the core material increases by that much, Although the temperature rise at the end portion becomes unstable, such an inconvenience is eliminated according to this embodiment.

For example, when the distance between both ends of the core member 2 (flange portion 11b of the power supply cap holder) and the flange portion 20a (thrust stop portion) of the power supply brush holder 20 is equal, the length is set to Wc. Assuming that the protrudable amount of the power supply brush 21 shown in FIG. 4B is Wb, Wb> Wc
The spring and holder are set so that With this configuration, the maximum thrust play (W
Even when the movement c) occurs, the power supply brush 21 and the power supply portion (power supply cap 10) of the core material do not separate from each other, so that reliable power supply can be guaranteed. That is, the distance Wc
Even if the core member moves in the axial direction by the amount, the protrudable amount Wb of the power supply brush 21 is larger than Wc, so that the contact state with the power supply cap can be maintained.

The contact between the power supply brush holder 20 also serving as a thrust stopper and the core material 2 (contact when a thrust load is generated) is performed via a member (power supply cap holder 11) that rotates integrally with the core material. Therefore, the degree of freedom in layout is increased, and it is possible to easily take measures against abrasion powder of the drive unit and the power supply brush. Flange 11b of power supply cap holder
And the surface facing the flange portion 20a of the power supply brush holder is a flat surface over the entire circumference, and the irregularities descend to the contents. As a result, the function of stopping the thrust can be exerted without bias. Specifically, a layout with a high degree of freedom can be performed without causing rotation abnormality due to catching, and cost can be reduced.

FIG. 5 is a sectional view showing the other end of the core material constituting the heating roller of the present invention, that is, the driving side of the roller.
A drive gear (a member integrated with the core) 30 is fixed to the outer peripheral surface of the other end of the core 2. The drive gear can be fixed by, for example, fitting a part of the drive gear on the inner diameter side into a U-groove 31 formed by cutting out the end edge of the core material, and rotates integrally with the core material. The power supply cap 10 and the power supply cap holder 11 used on the end side are substantially the same as those used on the end side shown in FIG. 4, but the power supply cap holder 11 corresponds to the U-groove 31 described above. The part to be cut out is partially cut out. The brush holder 20 used on the end side is the same as the case of FIG.
a thrust stopper 2 in which a part of a protrudes toward the drive gear 30
0c. The thrust stopper 20c is opposed to the axially outer end surface 30a of the drive gear 30 with a predetermined clearance so as not to give unnecessary resistance to rotation of the core member, and to provide a thrust stopper function. And functions to prevent the drive gear from slipping off. The outer surface that comes into contact with the brush holder on the drive gear side has a flat shape all around. As a result, the function of the thrust stopper can be exerted without bias. A layout with a high degree of freedom can be performed without causing rotation abnormality due to catching, and cost can be reduced.

FIG. 6 is a cross-sectional view showing another example of the configuration of the driving-side end portion, which is the same as that of FIG. 5. In this embodiment, a projection 30a is provided on a part of the axially outer end surface of the driving gear. Protrusion 3
0a and the flange portion 20a of the brush holder 20 are opposed to each other with a predetermined clearance. Therefore,
The power supply brush holder 20 does not apply a driving load due to non-contact with the core (drive gear) when the core rotates, and has a thrust stop function when the core moves in the axial direction. It is able to fulfill. The surface of the power supply brush holder 20 facing the protrusion 30a of the drive gear 30 is formed in a flat shape over the entire circumference. The end face of the projection 30a is also formed in a planar shape. As a result, the function of the thrust stopper can be exerted without bias. Specifically, a layout with a high degree of freedom can be performed without causing rotation abnormality due to catching, and cost can be reduced.

Next, FIG. 7 is a sectional view of a main part of another embodiment of the present invention, and shows a power supply structure in a type in which the power supply cap holder 11 is omitted from the end structure of FIG. In this embodiment, the thrust stop function is achieved by arranging the flange portion 20a of the power supply brush holder 20 and the end of the core material 2 with a certain clearance therebetween. Except for omitting the power supply cap holder, this embodiment is the same as the embodiment of FIG. 5 and 6 may be combined with the embodiment shown in FIG. 4 or with the embodiment shown in FIG.

Next, FIG. 8 is different from the type in which the power is supplied to the heating resistor 5 formed on the inner surface of the core material, like the power supply structure of the self-heating type heating roller of each of the above embodiments. The material 2 itself is a heat-generating resistor, and a power-supply brush 21 is directly applied to an end in the axial direction to supply power and generate heat. In this embodiment, the holding portion 20b of the power supply brush holder
Is arranged to face the end of the core material 2, while the holding portion 20 b
A predetermined clearance is provided between the projection (e.g., the thrust stopper) 20e at the tip of the protruding piece 20d derived from the core material in the diameter direction of the core material, at the end of the core material (at a position shifted by 180 degrees from the end of the core material where the power supply brush contacts). They are arranged to face each other. That is, the brush holder 20 has a clearance with the core power supply portion and performs a thrust stop function at the core material circumferential position on the opposite side to the portion where the power supply brush 21 is in contact. Even if the brush holder 20 is arranged so as to possibly come into direct contact with the roller power supply portion, there is no problem since the brush holder is originally made of an insulating material that can hold the power supply brush 21. Does not occur. The projection 20e is a flat surface and is parallel to the opposite end of the core material 2. As a result, a layout having a high degree of freedom can be performed without causing rotation abnormality due to catching, and cost can be reduced. As the configuration of the other end (drive side) when the embodiment of FIG. 8 is employed, the same configuration as the configuration of FIG. 8 can be employed.

As described above, according to each embodiment of the present invention,
As means for supplying power to the heating resistor formed on the inner surface of the hollow cylindrical core material or to the core material itself, the power supply brush holder fixed to the fixing device main body is held so as to be able to protrude freely and in the protruding direction. Using an elastically biased power supply brush,
The power supply brush is pressed against the center of the power supply cap arranged inside the core material, or is pressed directly against the end of the core material. It can be carried out. In addition, since a part of the power supply brush holder is opposed to the core material or the power supply cap holder with a predetermined clearance therebetween, the power supply brush holder may always have resistance to the rotation of the core material as a rotating body. In addition, when the core material is going to move in the axial direction, it can be restricted and function as a thrust stopper.

A bearing 25 for rotatably supporting the heating roller 1 with respect to the casing of the fixing device,
A space for providing the driving gear portion 30 fixed to the outer peripheral surface of the heating roller and receiving the driving force is ensured at an axially outer position (extremely small non-heating area) of the power supply cap 10 and the conventional driving gear is provided. The difference between the axial length of the heating roller and the width of the heating element is made as small as possible by omitting the C-ring for stopping the thrust disposed outside the gear portion in the axial direction, and the maximum paper passing width and the heating roller length are reduced. As a value as close as possible, it was possible to minimize the phenomenon of insufficient heating of the end of the heating roller. Another object of the present invention is to enable good power supply without increasing the length of the heating roller in the axial direction, increasing wear of the power supply terminal, and increasing drive load. As a result, all of the above-mentioned problems in the prior art can be solved with a simple configuration without increasing the cost.

[0022]

As described above, according to the first aspect of the present invention, the self-heating type heating for fixing by making the core material of the hollow cylinder itself or the heating resistor layer integrally formed on the inner surface of the core material generate heat. In the roller, the power supply to the self-heating type heating roller is configured such that the power supply terminal is contact-powered by pressing the power supply terminal from the axial end side of the roller to the core material end portion or the power supply cap inside the core material, Further, a power supply brush holder (power supply terminal holder) made of a non-conductive resin for holding the power supply brush (power supply terminal) is provided, and the power supply brush holder is provided with a thrust stopping function of the self-heating type heating roller. The length of the self-heating type heating roller can be shortened by omitting the use of the roller, and as a result, the problems of the above-described prior art with a simple configuration (wear of the power supply brush, poor temperature rise of the end portion temperature, etc.) Break It is possible, miniaturization of the fixing device and, it is possible to reduce the cost. According to a second aspect of the present invention, in the first aspect, when the core material moves in the axial direction to such an extent that the clearance between the core material and the power supply brush holder disappears, that is, when a movement corresponding to the maximum thrust play of the thrust stopping function occurs. In this case, since the power supply brush and the power supply portion (power supply cap) of the core material are not separated from each other, reliable power supply can always be guaranteed. According to a third aspect of the present invention, in the first aspect, contact between the power supply brush holder also serving as a thrust stopper and the core member (contact when a thrust load is generated).
Is performed through members (power supply cap holder and drive gear) that rotate integrally with the core material, so that the degree of freedom in layout is increased, and measures against wear powder of the drive unit and the power supply brush can be easily performed.

According to a fourth aspect of the present invention, in any one of the first and third aspects, the core member, the power supply cap holder, or the drive gear, which is in direct contact with the power supply brush holder for the thrust stop function, faces the power supply brush holder. Surface is flat over the entire length in the circumferential direction, and there is no unevenness, so there is no collision with the power supply brush holder,
The inclination of the core member when the core member is thrust-stopped is eliminated. In addition, a layout having a high degree of freedom can be performed without causing rotation abnormality due to catching, and cost can be reduced. According to the fifth aspect, the surface of the power supply brush holder facing the core material portion or the power supply cap holder or the drive gear is made flat over the entire length in the circumferential direction, and there is no unevenness. There is no contact with the brush holder, and the inclination of the core when the thrust is stopped is eliminated. In addition, a layout having a high degree of freedom can be performed without causing rotation abnormality due to catching, and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a self-heating type heating roller to which the present invention is applied.

FIGS. 2 (a), (b), (c) and (d) are an exploded perspective view, an exploded sectional view, and a sectional view showing an assembled state of a main part.

3A is a diagram showing an outline of a fixing device using a self-heating type roller of the present invention, and FIG. 3B is a configuration diagram of a conventional example.

4A is a cross-sectional view illustrating a configuration of a main part of an embodiment of the present invention, and FIG. 4B is a configuration diagram of a power supply brush and a brush holder.

FIG. 5 is a sectional view showing a configuration of a main part of another embodiment of the present invention.

FIG. 6 is a sectional view showing a configuration of a main part of another embodiment of the present invention.

FIG. 7 is a sectional view showing a configuration of a main part of another embodiment of the present invention.

FIG. 8 is a sectional view showing a configuration of a main part of another embodiment of the present invention.

[Explanation of symbols]

1 heating roller, 2 core material, 3 release layer, 4 insulation layer,
Reference Signs List 5 heating resistor, 6 conductive tape, 10 power supply cap, 10a central part (projection), 11 power supply cap holder, 11a surface, 11b flange, 15 retaining ring,
Reference Signs List 20 brush holder, 20a flange portion (thrust stopping portion), 20b holding portion, 21 power supply brush (power supply terminal), 22 spring, 25 bearing,

Claims (5)

[Claims] 1. A self-heating type heating roller for fixing by heating a hollow cylindrical core material or a heating resistor layer integrated with the core material, wherein power is supplied to the self-heating type heating roller. This is performed by pressing the power supply brush against a power supply cap disposed in the end portion or the hollow inside of the core material.The power supply brush is held by a power supply brush holder made of a non-conductive resin so as to be able to advance and retreat in the axial direction, The self-heating type heating roller is characterized in that the power supply brush holder exerts a thrust stopping function for restricting axial movement of the core material by pressing the power supply brush against the power supply cap. 2. The power supply brush is elastically urged in a protruding direction by a spring provided on the power supply brush holder,
The self-heating type heating roller according to claim 1, wherein even when the core moves a maximum distance in the axial direction, the contact state between the power supply brush and the power supply cap is maintained. 3. The self-heating type heating roller according to claim 1, wherein the contact between the power supply brush holder and the end of the core material is performed via a member fixed to the core material. . 4. The member fixed to the core member, a surface facing the power supply brush holder is a flat surface over the entire circumference in a circumferential direction. 3
The self-heating type heating roller as described in the above. 5. The power supply brush holder according to claim 1, wherein a surface of the power supply brush holder facing the member fixed to the core material is a flat surface over the entire circumference. Self-heating type heating roller.