JP2001160476A - Heating roller and toner fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability in supplying the heating roller with electricity. SOLUTION: The heating roller 1 is basically a resistance heat sheet 20 formed along the inner periphery of a metal crude tube 10. Most characteristic of the device is that it is provided with ring-shaped insulation spacers 30 mounted on both ends of the metal tube 10, a shaft center part 42 for the roller, and also shaft-shaped terminals 40 mounted inside the insulation spacer 30, and, further, an electrode 21 formed at both sides of the resistance heat sheet 20 toward shaft center direction is taken out of the inner periphery of the metal crude tube 10 to be pinched between the inner periphery of the insulation spacers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating roller on which a resistance heat sheet is formed along an inner circumferential direction of a roller body, and a toner fixing device having the heating roller.

[0002]

2. Description of the Related Art In a toner fixing device in an electrophotographic system such as a copying machine or a printer, a recording paper on which a toner image has been transferred passes between a heating roller and a pressure roller, and the toner image is pressed by heating and simultaneously. Is thermally fixed on recording paper. Heating rollers generally have a structure in which a light-emitting heating tube such as a halogen lamp is provided inside a roller body which is a metal tube, but in recent years, the speed and power consumption of electrophotographic systems have been reduced. According to the demand, a roller having a structure in which a resistance heat sheet is formed along a circumferential direction of a roller body is often used. Japanese Patent Application Laid-Open No. 10-186918 discloses an example of this type of heating roller.
Japanese Patent Application Laid-Open No. 9-265245 (hereinafter referred to as a first conventional example)
(Referred to as a second conventional example).

FIG. 5 is a partial sectional view of a first conventional heating roller. The roller body 100 is supported by a bearing 140. While an insulating layer 101 and a resistance heating layer 102 are sequentially formed on the inner peripheral surface of the roller body 100,
A release layer 103 is formed on the outer peripheral surface. Power receiving members 110 are mounted on both sides of the roller body 100. The power receiving member 110 is bonded and fixed to the resistance heating layer 102 with a conductive adhesive and is electrically connected. The power feeding member 130 pressed by the spring 120 is in surface contact with the flat top surface of the power receiving member 110. That is, the resistance heating layer 102
Power is supplied to the power supply member 130 and the power receiving member 110 sequentially.

FIG. 6 is a partial sectional view of a heating roller according to a second conventional example. The roller main body 200 is supported by a bearing 260. An insulating layer 201 and a resistance heating layer 202 are sequentially formed on the inner peripheral surface of the roller body 200, and electrode layers 203 are formed on both ends of the resistance heating layer 202. On the other hand, the release layer 204 is provided on the outer peripheral surface of the roller body 200.
Are formed.

[0005] Cap-shaped electrodes 210 are attached to both ends of the roller body 200. A ring-shaped electrode 220 and an electrode piece 230 are mounted in a hole formed in the center of the cap-shaped electrode 210. The end of the electrode piece 230 is in urge contact with the electrode layer 203. Ring electrode 220
A rod-shaped electrode 240 is mounted at the center of the. The end of the rod electrode 240 is supported by the electrode holder 250.
That is, power is supplied to the resistance heating layer 202 by the rod-shaped electrode 240,
The operation is performed sequentially through the ring-shaped electrode 220, the electrode piece 230, and the electrode layer 203.

[0006]

However, in the case of the first conventional example, the power receiving member 110 and the resistance heating layer 102
Is electrically and mechanically connected to each other by a conductive adhesive, which has an inherent disadvantage of low reliability in supplying power. If there is uneven bonding or the like, not only the mechanical strength is significantly reduced, but also the conduction becomes partially defective, and a partial concentration of current may cause local heat generation, which may burn the heating roller.

On the other hand, in the case of the second conventional example, the electrode piece 2
The electrode piece 230 and the electrode layer 203 by utilizing the elastic force of
Is electrically connected between the
As in the conventional example, there is an essential disadvantage that the reliability in supplying electric power is low.

The present invention has been made in view of the above background, and has as its object to provide a heating roller having high reliability in supplying electric power and a toner fixing device using the same. It is in.

[0009]

A heating roller according to the present invention is a heating roller having a resistance heat sheet formed along an inner peripheral surface of a roller body, the heating roller being a ring-shaped member, and both ends of the roller body. A pair of insulating spacers respectively attached to the parts, a cylindrical or cylindrical main body having an outer diameter slightly smaller than the inner diameter of the insulating spacer, and a roller core formed at the center of the end face of the main body. And a pair of axial power receiving terminals respectively mounted in the pair of insulating spacers, and the electrode portions formed on both sides in the axial direction of the resistance heat sheet are provided on the inner periphery of the roller body. It is characterized in that it is drawn out from the surface and is sandwiched between each inner peripheral surface of the pair of insulating spacers and each outer peripheral surface of the main body of the pair of axial power receiving terminals.

In the case of such a configuration, insulating spacers are respectively attached to both ends of the roller body, and the electrode portions of the resistance heat sheet drawn out from the inner peripheral surface of the roller body are respectively positioned on the inner peripheral surface of the insulating spacer. In this state, when the shaft-shaped power receiving terminals are respectively mounted in the insulating spacer, the electrode portions of the resistive heat sheet are sandwiched between the inner peripheral surface of the insulating spacer and the outer peripheral surface of the main body of the shaft-shaped power receiving terminal. The sheet and the shaft-shaped power receiving terminal are electrically connected to each other. Power is supplied to the resistance heat sheet through each of the axial power receiving terminals.

[0011] More preferably, a groove for inserting the electrode portion of the resistance heat sheet is formed in the inner peripheral surface of the insulating spacer in the axial direction. This is because the contact area between the inner peripheral surface of the insulating spacer and the outer peripheral surface of the main body of the axial power receiving terminal is increased, and the axial power receiving terminal can be securely mounted on the insulating spacer.

In this case, in order to reduce stress acting on the axial power receiving terminal when the terminal is inserted into the insulating spacer, a step is formed on the insertion side of the terminal in the groove. desirable.

In mounting the insulating spacer on the end of the roller main body, the insulating spacer and the roller main body are provided with a concave portion or an engaging portion for aligning the electrode portion of the resistance heat sheet with the groove. It is desirable to form the convex portion as the positioning means. This is because, when the insulating spacer is attached to the end of the roller body, the electrode portion of the resistance heat sheet and the groove can be easily aligned.

[0014] More preferably, it is desirable to form a projection on the outer peripheral surface of the main body of the shaft-shaped power receiving terminal to ensure contact with the electrode portion of the resistance heat sheet inserted into the groove. .

In this case, when the shaft-shaped power receiving terminal is mounted on the insulating spacer, the shaft-shaped power receiving terminal and the insulating spacer are provided with a concave portion or a convex portion engaging with the electrode portion so as to align the electrode with the projection. Is desirably formed as positioning means. This is because when the shaft-shaped power receiving terminal is mounted on the insulating spacer, the alignment between the electrode portion and the projection can be easily performed.

Another heating roller according to the present invention is a heating roller in which a resistance heat sheet is formed along the inner peripheral surface of the roller body, and has a cylindrical or cylindrical shape having an outer diameter slightly smaller than the inner diameter of the roller body. And a pair of shaft-shaped power receiving terminals respectively mounted on both ends of the roller body. Electrodes formed on both sides of the heat sheet in the axial direction and the outer peripheral surfaces of the main bodies of the pair of axial power receiving terminals are in contact with each other.

In such a configuration, when the shaft-shaped power receiving terminals are attached to both ends of the roller body, the electrode portion of the resistance heat sheet comes into contact with the outer peripheral surface of the body of the shaft power reception terminal, and the resistance heat sheet and The shaft-shaped power receiving terminals are electrically connected to each other. Power is supplied to the resistance heat sheet through each of the axial power receiving terminals.

[0018] More preferably, it is desirable to form a projection on the outer peripheral surface of the main body of the shaft-like power receiving terminal to ensure contact with the electrode portion of the resistance heating sheet.

The toner fixing device according to the present invention is a device for thermally fixing a toner image transferred on a recording sheet to the recording sheet, wherein the heating roller for generating heat necessary for heat fixing is provided;
A pair of bearings attached to frames provided on both sides of the heating roller and supporting the shaft portions of the pair of shaft-shaped power receiving terminals, respectively, and supplying power to be supplied to the heating roller to the shaft portions. And a pair of power supply mechanisms. The power supply mechanism includes a power supply body electrically connected to a power supply for supply to the heating roller, a pressing spring for urging the power supply body into contact with the end surface of the shaft core of the shaft-shaped power receiving terminal, and a frame including the power supply body together with the pressing spring. It is good to use the thing provided with the power supply body holder which supports.

With this configuration, the power generated by the power supply for the heating roller is supplied to the heating roller sequentially via a part of the power supply mechanism and the axial power receiving terminal. The shaft-shaped power receiving terminal serves not only as a power supply path to the heating roller but also as a shaft center of the roller body.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a partial sectional view of a toner fixing device, FIG. 2 is an exploded perspective view of a heating roller of the same, FIG. 3 is a perspective view of a resistance heating sheet of the heating roller, and FIG. FIG.

The toner fixing device described here is a copying machine,
This is provided in an electrophotographic system such as a printer, and as shown in FIG. 1, a recording paper P on which a toner image has been transferred passes between a heating roller 1 and a pressure roller 2, and is heated and pressurized simultaneously with toner. It has a basic configuration in which an image is thermally fixed on recording paper. Since the structure near both ends of the heating roller 1 is the same, only the vicinity of one end of the heating roller 1 is shown in FIGS.

First, the configuration of the heating roller 1 used in the apparatus will be described with reference to FIGS. The heating roller 1 is a metal tube 10 (corresponding to a roller body).
Has a basic configuration in which the resistance heat sheet 20 is formed along the inner peripheral surface of the sheet. The most characteristic is a ring-shaped member, and a pair of insulating spacers 30 and 30 respectively attached to both ends of the metal tube 10, and a roller core 4
2 and a pair of axial power receiving terminals 40, 40 mounted in the insulating spacers 30, 30, respectively. The electrode portions 21 formed on both sides of the resistance heat sheet 20 in the axial direction are made of metal. It is pulled out from the inner peripheral surface of the base tube 10, and is sandwiched between each inner peripheral surface of the insulating spacers 30, 30 and each outer peripheral surface of the main body 41 of the axial power receiving terminals 40, 40. On the point.

The metal tube 10 is an aluminum tube or an iron tube. Concave portions 11, 11 that engage with convex portions 33, 33 (described later) of the insulating spacers 30, 30 are respectively formed on the outer peripheral surfaces of both ends of the metal tube 10.

As shown in FIG. 3, the resistance heat sheet 20 has a structure in which a metal sheet 23 as a metal foil pattern is formed on an insulating layer 22 which is a resin film of polyimide or the like. It is stuck on the inner surface.

The length of the insulating layer 22 in the longitudinal direction is M
And is set to the same value as the entire length of the metal element tube 10 or a value close thereto.

The metal sheet 23 is made of aluminum, nickel, stainless steel, copper or iron (including galvanized iron).
And the like are formed on the insulating layer 22 by vapor deposition, lamination of foil, or the like, and then formed by etching, lithography, or the like into a pattern having a shape as shown in the drawing. On both sides of the metal sheet 23 in the longitudinal direction, strip electrodes 231 and 231 are provided.
Are provided outside the insulating layer 22, and these are used as the electrode portions 21 of the resistance heating sheet 20.

The resistance heat sheet 20 having such a structure is bent into a roll shape with the metal sheet 23 inside, and is inserted into the metal tube 10 and attached.

As shown in FIGS. 1 and 2, the insulating spacer 30 has a cylindrical main body 3 inserted into the metal tube 10.
1 and a flange 32 formed on the outer edge of the main body 31
It is a resin molded product composed of On the outer peripheral surface of the insulating spacer 30, a convex portion 33 that engages with the concave portion 11 of the metal tube 10 is provided.
Are formed, and grooves 34, 34, 3 in which the electrode portions 21 of the resistance heat sheet 20 are inserted are formed on the inner peripheral surface thereof.
4 are formed at a pitch of 120 ° in the axial direction. Note that the protrusion 33 is formed at a position above one of the grooves 34.

A shaft-like power receiving terminal 40 is provided in the insulating spacer 30.
The electrode portion 21 of the heat sheet 20 is attached. In order to reduce the stress acting on the axial power receiving terminal 40 at that time, a step 341 (see FIG. Reference) is formed.

When the insulating spacer 30 is attached to the end of the metal tube 10 by the concave portion 11 of the metal tube 10 and the convex portion 33 of the insulating spacer 30, the electrode portion 21 of the resistance heat sheet 20 and the insulating spacer are attached. Positioning means for positioning the 30 with the groove 34 is provided. A convex portion may be formed on the metal tube 10 and a concave portion may be formed on the insulating spacer 30.

Further, on the inner peripheral surface of the insulating spacer 30, convex portions 35, 35, 35 which engage with concave portions 411 (described later) of the shaft-like power receiving terminal 40 are formed at intervals of 120 °.

The axial power receiving terminal 40 has a cylindrical main body 41 having an outer diameter slightly smaller than the inner diameter of the insulating spacer 30.
It is a molded product made of copper or the like having a roller shaft portion 42 formed at the center of the end face of the main body portion 41. A part of the edge of the main body 41 is cut out, and the protrusion 3 of the insulating spacer 30 is formed.
5 as recesses 411, 411, 411
Are formed at a pitch interval of °.

The insulating spacer 30 is provided on the outer peripheral surface of the main body 41.
Electrode portion 2 of resistance heat sheet 20 inserted in groove 34
Projections 412, 412, 4 to ensure contact with
12 are formed at pitch intervals of 120 °. The projections 412 are formed by punching the main body 41 into a U-shape, and slightly floating the punched portion outward.

The concave portion 411 of the axial power receiving terminal 40 and the convex portion 35 of the insulating spacer 30 form the axial power receiving terminal 40.
When mounting on the insulating spacer 30, the electrode portions 21 of the resistance heat sheet 20 and the protrusions 412 of the axial power receiving terminals 40 are provided.
And a positioning means for performing positioning with respect to. A convex portion may be formed on the axial power receiving terminal 40 and a concave portion may be formed on the insulating spacer 30.

A method of assembling the heating roller 1 configured as described above will be described with reference to FIG. First, the resistance heat sheet 20 is bent into a roll shape with the metal sheet 23 inside, and is inserted into the metal tube 10. At this time, the electrode portion 21 of the resistance heat sheet 20 is
Pull out from the inner peripheral surface. Then, the resistance heat sheet 20 is attached to the inside of the metal tube 10 using an adhesive or the like.

Next, the main body 31 of the insulating spacer 30 is inserted into both ends of the metal tube 10 while aligning the concave portion 11 of the metal tube 10 with the convex portion 33 of the insulating spacer 30. Then, the electrode portion 21 of the resistance heat sheet 20 enters the groove 34 of the insulating spacer 30 and the insulating spacer 3
The 0 convex portion 33 enters and engages with the concave portion 11 of the metal tube 10. Then, the insulating spacer 30 is attached to the metal tube 10 by press-fitting or using an adhesive or the like.

Thereafter, the main body 4 of the shaft-like power receiving terminal 40 is placed in the insulating spacer 30 while the projection 33 of the insulating spacer 30 and the projection 412 of the shaft-like power receiving terminal 40 are aligned.
1 is press-fitted. Then, the protrusion 412 of the axial power receiving terminal 40 comes into contact with the electrode portion 21 of the resistance heat sheet 20 inserted into the groove 34 of the insulating spacer 30, and the insulating spacer 30
Of the shaft-shaped power receiving terminal 40 is engaged with the concave portion 411 of the shaft-shaped power receiving terminal 40. Then, the axial power receiving terminal 40 is attached to the insulating spacer 30 by press-fitting or using an adhesive or the like.
Thus, the assembly of the heating roller 1 is completed.

With the above-described heating roller 1, the assembly process is very simple. In particular, positioning means (the concave portion 11 and the convex portion 33) between the metal tube 10 and the insulating spacer 30 and positioning means (the convex portion 35 and the concave portion 411) between the insulating spacer 30 and the axial power receiving terminal 40 are provided. As a result, the assembling work can proceed smoothly.

Since the groove 34 into which the electrode portion 21 of the resistance heat sheet 20 is inserted is formed in the inner peripheral surface of the insulating spacer 30, the inner peripheral surface of the insulating spacer 30 and the shaft-like power receiving terminal 40 are formed. The contact area between the outer peripheral surface of the main body portion 41 and the outer peripheral surface of the main body portion 41 is increased, and the axial power receiving terminal 40 can be securely mounted on the insulating spacer 30. In addition, since the step 341 is formed in the groove 34 of the insulating spacer 30, it acts on the axial power receiving terminal 40 and the electrode portion 21 of the deheat sheet 20 when the axial power receiving terminal 40 is mounted in the insulating spacer 30. Stress is reduced. In these respects, the productivity is improved.

Further, the reliability in supplying electric power to the heating roller 1 is improved. The reason is that the power supply to the heating roller 1 is performed through the shaft-shaped power receiving terminal 40, but the electrical and mechanical connection between the electrode portion 21 of the resistance heating sheet 20 and the shaft-shaped power receiving terminal 40 for the following reason. Is performed reliably.

First, the electrode portion 21 of the resistance heat sheet 20
Are sandwiched between the insulating spacer 30 and the axial power receiving terminal 40, and the protrusion 412 of the axial power receiving terminal 40 is in urge contact with the electrode portion 21. Moreover, the engagement between the concave portion 11 of the metal tube 10 and the convex portion 33 of the insulating spacer 30 and the insulating spacer 3
The engagement between the 0 convex portion 35 and the concave portion 411 of the axial power receiving terminal 40 maintains the positional relationship between the electrode portion 21 and the protrusion 412. As a result, the electrical and mechanical connection between the electrode portion 21 and the shaft-like power receiving terminal 40 is ensured, and there is no possibility that local heat generation due to poor conductivity occurs.

As described above, not only the assembling process of the heating roller 1 is extremely simplified, but also the inspection process is simplified due to the high reliability in supplying power.
Also, the state in which the electrode portion 21 of the resistance heat sheet 20 is sandwiched between the axial power receiving terminal 40 and the insulating spacer 30 can be seen through the step 341 formed in the groove 34 of the insulating spacer 30. Can be easily performed, and the inspection work can be performed smoothly in this respect as well.

As described above, since both the production process and the inspection process can be simplified, it is suitable for mass production, the production yield is improved, and the cost can be reduced.

The heating roller 1 may use a resistance heat sheet 20 'as shown in FIG. That is, a metal sheet 23 'as a metal foil pattern is formed on an insulating layer 22' as a resin film of polyimide or the like. Rectangular electrodes 231 'are provided on both sides of the metal sheet 23' in the longitudinal direction. A strip-shaped electrode 24 'is bonded on the electrode 231' using a conductive adhesive or the like. A part of the strip-shaped electrode 24 ′ extends out of the insulating layer 22, and is connected to the electrode portion 2
1 '. Here, the number of the electrode portions 21 'is four.

When such a resistive heat sheet 20 'is used, it can be formed simply by sticking the strip-shaped electrodes 24' to an existing resistive heat sheet, which is advantageous in terms of cost.

Next, a detailed structure around the heating roller 1 of the toner fixing device will be described with reference to FIG. The apparatus is attached to a heating roller 1 for generating heat necessary for heat fixing and frames 3 provided on both sides of the heating roller 1 and the like. A pair of bearings 4 and 4 to be supported, and a power supply mechanism 5 for supplying power to be supplied to the heating roller 1 to the shaft cores 42 and 42, respectively.
5 is provided.

The power supply mechanism 5 includes a power supply 51 that is electrically connected to a power supply for a heating roller (not shown) via a power supply line, and a power supply 5.
A pressing spring 52 for biasing the end 1 of the shaft core portion 42 of the shaft-shaped power receiving terminal 40 into contact with the end surface of the shaft receiving member 40, and a resin molded product formed in a bottomed cylindrical shape, and the power feeding body 51 is framed together with the pressing spring 52 3 and an insulative power supply holder 53 supported by the support 3.

That is, the heating roller 1 is rotatably supported by bearings 4 and 4 attached to the frame 3 and is mechanically connected to a motor (not shown) via a tension belt to rotate. . The same applies to the pressure roller 2. Power is supplied to the resistance heat sheet 20 (or 20 ′) of the heating roller 1 by the power supply bodies 51 and 5.
1. The operation is performed sequentially through the axial power receiving terminals 40, 40 and the electrode portions 21, 21.

At this time, since the power supply 51 is in contact with not the side surfaces of the shaft cores 42 and 42 of the heating roller 1 but the end surfaces on the axis, wear of both contact surfaces is very small.

The heating roller 1 is driven by a driving force of a motor (not shown).
When the pressure roller 2 rotates and the recording paper P passes between the two rollers, heat is fixed by the heat generated by the heating roller 1 while being pressed by the tensile force of a tension belt or the like.

In the toner fixing device configured as described above, the cost of the entire apparatus can be reduced as the cost of the heating roller 1 is reduced. In particular, the heating roller 1
Has a function not only as a power supply path to the resistance heating sheet 20 but also as a shaft core of the metal tube 10, so that the structure around the heating roller 1 is simplified. In terms of cost, the cost can be reduced. In addition, since the reliability of the heating roller 1 is high, there is a great merit in improving the reliability of the toner fixing device and the electrophotographic system.

The heating roller of the present invention can be applied not only to a toner fixing device but also to an offset printing device and the like. Also, the electrode portions formed on both sides in the axial direction of the resistance heat sheet are drawn out from the inner peripheral surface of the roller body, and are sandwiched between the inner peripheral surface of the insulating spacer and the outer peripheral surface of the main body of the axial power receiving terminal. Any configuration may be used as long as the configuration allows the above.

The resistance heat sheet is formed along the inner circumferential direction of the roller body, and as long as it generates heat when power is supplied, its type (for example, formed by resistor printing or the like), The shape, arrangement position, and the like are not limited.
Further, the number, shape, and the like of the electrode portions of the resistance heat sheet may be appropriately selected according to the magnitude of the current.

The shaft-shaped power receiving terminal may have any structure as long as it has both a function as a shaft for the roller and a function as a power supply path to the resistance heat sheet. It may be. In addition, if the roller body is insulative, an insulating spacer is not required, so that the shaft-shaped power receiving terminals may be directly disposed at both ends of the roller body. Even in this case, as long as the configuration is such that the electrode portion of the resistance heat sheet is pulled out from the inner peripheral surface of the roller main body and is sandwiched between the inner peripheral surface of the roller main body and the outer peripheral surface of the main body of the axial power receiving terminal. The same effect as above can be expected. Also in this case, it is preferable to form a protrusion on the outer peripheral surface of the shaft-shaped power receiving terminal to ensure contact with the electrode portion of the resistance heat sheet.

The toner fixing device of the present invention may be of any type as long as it has the above-mentioned heating roller. The power supply mechanism may be of any configuration as long as the power to be supplied to the heating roller is supplied to the shaft core of the heating roller. Alternatively, a configuration may be used in which a bearing that supports the shaft core portion is used as a power supply.
The bearing may be configured to use a part of a frame arranged on both sides of the heating roller.

[0057]

As described above, in the case of the heating roller according to the first aspect of the present invention, insulating spacers are respectively attached to both ends of the roller body, and the electrode portions of the resistance heat sheet drawn out from the inner peripheral surface of the roller body are insulated. When the shaft-shaped power receiving terminals are respectively mounted in the insulating spacers in this state, the electrode portions of the resistance heat sheet are positioned on the inner circumferential surface of the insulating spacer and the outer circumferential surface of the body portion of the shaft-shaped power receiving terminals. And between the resistance heat sheet and the shaft-like power receiving terminal are structurally and strongly connected electrically. Therefore, the reliability in supplying power is improved as compared with the case of the conventional example. As a result, the inspection work becomes very simple, which is advantageous in reducing the cost.

In the case of the heating roller according to the second aspect of the present invention, the groove for inserting the electrode portion of the resistance heat sheet is formed in the inner peripheral surface of the insulating spacer in the axial direction. In addition, the contact area between the inner peripheral surface of the insulating spacer and the outer peripheral surface of the main body of the shaft-shaped power receiving terminal is increased, so that the shaft-shaped power receiving terminal can be securely mounted on the insulating spacer, thereby reducing costs. Becomes possible.

In the case of the heating roller according to claim 3 of the present invention, since a step is formed on the side of the groove where the shaft-like power receiving terminal is inserted, the shaft-like shaft-like power receiving terminal is placed inside the insulating spacer. It is possible to reduce the stress acting on the terminal when inserting it into the terminal, and to facilitate the assembling work, thereby reducing the cost.

In the case of the heating roller according to the fourth aspect of the present invention, when the insulating spacer is attached to the end of the roller body,
Since the configuration is such that the electrode portion of the resistance heat sheet can be easily aligned with the groove, the assembling work can be simplified, and the cost can be reduced in this regard.

In the case of the heating roller according to the fifth aspect of the present invention, a projection for ensuring contact with the electrode portion of the resistance heat sheet inserted into the groove is formed on the outer peripheral surface of the main body of the axial power receiving terminal. Is formed, the reliability in supplying electric power is further improved.

In the case of the heating roller according to claim 6 of the present invention, when the shaft-shaped power receiving terminal is mounted on the insulating spacer, the positioning between the electrode portion and the projection can be easily performed. The assembling work can be simplified, and the cost can be reduced in this respect.

In the case of the heating roller according to claim 7 of the present invention, when the shaft-shaped power receiving terminals are respectively mounted on both ends of the roller body, the electrode portion of the resistance heat sheet formed on the inner peripheral surface of the roller body is formed in a shaft-shaped manner. Since the power receiving terminal is configured to be in contact with the outer peripheral surface of the main body, the resistance heat sheet and the axial power receiving terminal are structurally and strongly connected electrically. for that reason,
The reliability in supplying power is improved as compared with the case of the conventional example. As a result, the inspection becomes very simple, which is advantageous in reducing the cost.

In the case of the heating roller according to the eighth aspect of the present invention, a configuration is provided in which the projection for ensuring contact with the electrode portion of the resistance heating sheet is formed on the outer peripheral surface of the main body of the shaft-shaped power receiving terminal. Therefore, the reliability in supplying electric power is further improved.

In the toner fixing device according to the ninth and tenth aspects of the present invention, since the heating roller is provided, the reliability in supplying electric power to the heating roller is increased, and the cost is reduced. Can be achieved. In addition, the shaft-shaped power receiving terminal not only functions as a power supply path to the heating roller, but also functions as the axis of the roller body, which simplifies the structure around the heating roller and reduces costs in this regard as well. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a view for explaining an embodiment of the present invention, and is a partial cross-sectional view of a toner fixing device.

FIG. 2 is an exploded perspective view of a heating roller of the apparatus.

FIG. 3 is a perspective view of a resistance heat sheet of the heating roller.

FIG. 4 is an explanatory diagram for explaining a modified example of the resistance heat sheet.

FIG. 5 is a view for explaining a first conventional example, and is a partial cross-sectional view of a heating roller.

FIG. 6 is a view for explaining a second conventional example, and is a partial cross-sectional view of a heating roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating roller 10 Metal element tube 20 Resistance heat sheet 21 Electrode part 30 Insulating spacer 31 Main part 32 Flange part 33 Convex part 34 Groove 341 Step 35 Convex part 40 Shaft receiving terminal 41 Main part 411 Concave part 412 Projection 42 Shaft core part 3 Frame 4 Bearing 5 Power supply mechanism

Continued on the front page (72) Inventor Toru Imai 1-4-3 Kitakyuho-ji Temple, Yao-shi, Osaka F-term (reference) 2H033 BB12 BB19 BB21 BB22 3J103 AA02 AA13 AA24 AA38 AA41 AA74 BA05 CA02 EA07 EA08 FA30 GA02 GA57 GA58 GA66 HA01 HA03 HA06 HA20 HA31 HA32 HA33 HA36 HA37 HA46 3K058 AA28 BA18 DA04 DA14

Claims (10)

[Claims] 1. A heating roller in which a resistance heat sheet is formed along an inner peripheral surface of a roller main body, wherein a pair of insulating spacers which are ring-shaped members and are respectively attached to both ends of the roller main body; It has a cylindrical or cylindrical main body having an outer diameter slightly smaller than the inner diameter of the spacer, and a roller core formed at the center of the end face of the main body, and is provided in the pair of insulating spacers. A pair of shaft-like power receiving terminals respectively mounted, and electrode portions formed on both sides of the resistance heat sheet in the axial direction are pulled out from the inner peripheral surface of the roller body, and the pair of insulating spacers A heating roller, which is sandwiched between each inner peripheral surface of the pair and each outer peripheral surface of the main body of the pair of axial power receiving terminals. 2. The heating roller according to claim 1, wherein a groove into which an electrode portion of the resistance heat sheet is inserted is formed in an inner peripheral surface of the insulating spacer in an axial direction. Heating roller. 3. The heating roller according to claim 2, wherein when the shaft-shaped power receiving terminal is inserted into the insulating spacer, stress applied to the terminal is reduced so that the terminal is inserted into the groove. A heating roller having a step formed on a side thereof. 4. The heating roller according to claim 1, wherein when the insulating spacer is mounted on an end of the roller body, an electrode portion of the resistance heat sheet is aligned with the groove. A heating roller, wherein a concave portion or a convex portion engaging with the concave portion is formed as positioning means on the insulating spacer and the roller body. 5. The heating roller according to claim 1, wherein the outer peripheral surface of the main body of the shaft-like power receiving terminal is
A heating roller, wherein a projection is formed for ensuring contact with an electrode portion of the resistance heat sheet inserted into the groove. 6. The heating roller according to claim 5, wherein, when the shaft-shaped power receiving terminal is mounted on the insulating spacer, the shaft-shaped power receiving terminal is aligned with the protrusion. A heating roller, wherein a concave portion or a convex portion engaging with the concave portion is formed as positioning means on the insulating spacer. 7. A heating roller in which a resistance heat sheet is formed along an inner peripheral surface of a roller main body, wherein a cylindrical or columnar main body having an outer diameter slightly smaller than an inner diameter of the roller main body is provided. A roller shaft formed at the center of the end face, and a pair of shaft-shaped power receiving terminals attached to both ends of the roller body, respectively, in the axial direction of the resistance heat sheet. A heating roller, wherein electrode portions formed on both sides and outer peripheral surfaces of main bodies of a pair of axial power receiving terminals are in contact with each other. 8. The heating roller according to claim 7, wherein a projection is formed on an outer peripheral surface of the main body of the axial power receiving terminal to ensure contact with an electrode of the resistance heat sheet. A heating roller, characterized in that: 9. A toner fixing device for thermally fixing a toner image transferred on a recording sheet to the recording sheet, wherein heat required for heat fixing is generated.
Or a pair of bearings provided on a frame disposed on both sides of the heating roller and supporting the shaft cores of the pair of shaft-shaped power receiving terminals, respectively, and supplying the heating roller. A pair of power supply mechanisms for supplying power to be supplied to the shaft cores of the pair of shaft-shaped power receiving terminals, respectively. 10. The toner fixing device according to claim 9, wherein the power supply mechanism includes a power supply body electrically connected to the power supply for the heating roller, and a power supply body attached to an end surface of a shaft core of the shaft-shaped power receiving terminal. A toner fixing device comprising: a pressing spring that makes a force contact; and a power feeding holder that supports the power feeding body together with the pressing spring on the frame.