JP3031526B2 - Heating roller for fixing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can easily fix a resistance heating member composed of a sheet-like heating element sheet to the inner peripheral surface or the outer peripheral surface of a roller body, and can provide safety when energizing the resistance heating member. And a heating roller for fixing.

[0002]

2. Description of the Related Art Conventionally, an image recording apparatus using a toner, such as a copying machine or a printer, is provided with a recording mechanism, a fixing mechanism, a transport mechanism, and the like, and a toner image formed based on an image signal is transported. After the toner is adhered to the recording medium, a fixing heating roller provided in a fixing mechanism is brought into contact with the recording medium, so that the toner adhered to the recording medium is heated and fixed.

By the way, a resistance heating element is provided on the surface of the roller body so that it can be heated to a predetermined fixing temperature (for example, about 130 ° C.) in a short time after the power of the apparatus is turned on. Various fixing heating rollers have been proposed in which a driving current is supplied to a heating element via an electrode provided on a roller body so that the resistance heating element can generate heat. For example, in Japanese Patent Application Laid-Open No. 62-279378, an adhesion preventing layer for preventing toner on a recording medium from adhering to the roller main body is formed on the outer peripheral surface of the roller main body, while the adhesion preventing layer is formed on the inner peripheral surface of the roller main body. Forming a resistance heating element layer having a uniform thickness, further providing a pair of power supply members having disk-shaped brushes in contact with the resistance heating element layer from the inside, and adjusting the distance between the pair of power supply members. There has been proposed a fixing roller device in which only a roller portion optimal for a sheet width of a recording medium to be subjected to recording processing is efficiently heated by adjusting the driving roller mechanism.

[0004]

As described above, in the fixing roller device described in Japanese Patent Application Laid-Open No. 62-279378, an insulating layer for insulating the resistance heating element layer is provided on the inner peripheral surface of the roller body. Is formed, and the resistance heating element is fixed to the inner peripheral surface of the insulating layer. Therefore, in addition to the operation step of forming the insulating layer, a work step of fixing the resistance heating element is required. There are problems that the driving mechanism for moving the members is complicated, the manufacturing cost is increased, and the fixing mechanism is enlarged.

In general, since the amount of heat radiation is large at both ends in the axial direction of the rotatable fixing heating roller, the temperature at both ends tends to be lower than the temperature at the center. If such a state continues, fixing unevenness occurs due to non-uniform temperature distribution in the axial direction of the fixing heating roller during fixing of the recording medium, which may hinder formation of a good image. Therefore, it is necessary to increase the amount of heat generated at both left and right ends of the fixing heat roller to make the temperature distribution of the entire fixing heat roller uniform. In this case, it is necessary to reduce the thickness of the resistance heating element layer to increase the resistance value at the left and right ends, or to combine a material having a higher resistivity and capable of generating a large amount of heat, There is a problem that the production of a resistance heating element layer that can make the temperature distribution of the fixing heating roller uniform can be complicated and costly.

In this case, it is conceivable that the resistance heating element layer is formed of a belt-shaped resistance member meandering in a meandering pattern, but a belt-shaped resistance member is provided on the inner peripheral surface of the roller body having a roller diameter of 2 to 5 cm. There is a problem that the mounting operation for mounting the members while meandering the members in a predetermined pattern with high precision becomes very complicated, and a great amount of operation time is required.

Therefore, the inventor of the present application has proposed a resistance heating member which is a belt-shaped resistance heating element meandering in a predetermined meandering pattern, and which is connected to the resistance heating element and corresponds to both end portions of the roller body of the fixing heat roller. And a pair of belt-shaped power supply portions extending in the circumferential direction of the roller body, and a heating element sheet fixed on an insulating film material such as a polyimide resin, and the heating element sheet is bonded to an inner peripheral surface of the roller body with an adhesive. The idea was to supply a high voltage of, for example, 100 V to the resistance heating element via an energizing electrode that slidably contacts each power supply unit.

However, an error in the finishing accuracy of the inner peripheral surface of the roller body and an error in the length dimension of the heating element sheet corresponding to the circumferential length of the roller body occur. In the case of fixing the heating element sheet to the surface, a gap between the heating element sheets may be generated between one end and the other end of the roller body in the circumferential direction. In such a case, when the energizing electrode for supplying a high voltage faces the gap between the sheets, a discharge occurs between the energizing electrode and the roller body, increasing the danger and increasing the energizing electrode and its sheet. There is a problem that the roller body corresponding to the gap is burned.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing heat roller excellent in safety and durability so that current can be reliably supplied to a resistance heating element of a heating element sheet fixed to an inner peripheral surface or an outer peripheral surface of a roller body. To provide.

[0010]

According to a first aspect of the present invention, there is provided a fixing heating roller comprising: a cylindrical roller body; a resistance heating member provided on an inner peripheral surface of the roller body; A pair of electrodes for slidably contacting the resistance heating member and supplying current thereto, and fixing heating for heating and fixing toner attached to the recording medium conveyed in contact with the outer peripheral surface of the roller body. A roller, wherein the resistance heating member comprises a resistance heating element and a pair of belt-shaped power supply sections corresponding to both ends of the roller body and extending in the circumferential direction of the roller body, on the insulating film material; The heating element sheet is formed by fixing a pair of power supply units electrically connected to each other, and the insulating film material corresponding to at least one end of both circumferential ends of each power supply unit includes To overlap the insulating film material end corresponding to the other end A long portion is formed, and the heating element sheet is fixed to the inner peripheral surface of the roller body with the resistance heating element facing the center of the roller body. The film material is doubly overlapped via the extension.

According to a second aspect of the present invention, there is provided a fixing heat roller, a roller body formed in a cylindrical shape, a resistance heating member provided on an outer peripheral surface of the roller body, and generating heat by energization. A heating roller for fixing the toner adhered to the recording medium conveyed in contact with the outer peripheral surface of the roller body by heating and fixing the toner; The member is a pair of belt-like power supply portions on the insulating film material, the pair of belt-shaped power supply portions corresponding to both ends of the roller body and extending in the circumferential direction of the roller body, and is electrically connected to the resistance heating body. The insulating film material, which is constituted by a heating element sheet formed by fixing a pair of power supply sections and which corresponds to at least one end of both ends in the circumferential direction of each power supply section,
An extension is formed for overlapping with the end of the insulating film material corresponding to the other end, and the heating element sheet is fixed to the outer peripheral surface of the roller body with the resistance heating element facing the outside of the roller body, Further, at the positions at both ends of the pair of power supply portions, the insulating film material is double overlapped via the extension portion.

According to the third aspect of the present invention, there is provided a heating roller for fixing.
Alternatively, in the invention according to claim 2, the resistance heating element is formed of one or a plurality of belt-shaped resistance members meandering in a predetermined meandering pattern, and a pair of power supply portions is formed of the same material as the resistance member. is there. According to a fourth aspect of the present invention, there is provided the fixing heating roller according to the third aspect of the present invention, wherein the insulating film material has extended portions corresponding to both ends in the circumferential direction of each of the power supply portions, and the extended portions are overlapped doubly. Each power supply part is not formed in a part corresponding to the part. According to a fifth aspect of the present invention, in the heating roller for fixing, in the third aspect of the invention, the resistance heating element is made of a stainless steel foil film.

[0013]

In the heat roller for fixing according to the first aspect, the resistance heating member comprises a resistance heating element and a pair of belt-like members corresponding to both ends of the roller body and extending in the circumferential direction of the roller body on the insulating film material. And a heating element sheet formed by fixing a pair of feeding sections electrically connected to the resistance heating element, and at least one of both circumferential ends of each feeding section. Since the insulating film material corresponding to the end portion has an extension portion to be overlapped with the end portion of the insulating film material corresponding to the other end portion, the heating element sheet has its resistance heating element centered on the roller body. When it is fixed to the inner peripheral surface of the roller main body in a state facing the unit side, the insulating film material is double overlapped via the extension at the positions of both ends of the pair of power supply units. When the pair of electrodes slidably contact the power supply unit, the resistance heating element is energized through the power supply unit, and the current is generated by the resistance heating element.

Here, even when the circumferential length of the heating element sheet is short and a power supply gap is generated between both ends in the circumferential direction of each power supply section, the insulating film material is doubled via the extension. Even when a pair of electrodes faces the gap between the power supply portions, no discharge occurs between the roller body and the effect of the doubly overlapped insulating film material. The safety and durability of the fixing heating roller can be improved.

In the fixing heating roller according to the second aspect,
The operation is substantially the same as that of the first aspect, but differs in the following point. That is, the heating element sheet as the resistance heating member is fixed to the outer peripheral surface of the roller main body with the resistance heating element facing the outside of the roller main body. At this time, the insulating film material is overlapped doubly via the extension portions at the positions of both ends of the pair of power supply units. When the pair of electrodes slidably contact the power supply unit, the resistance heating element is energized through the power supply unit, and the current is generated by the resistance heating element. Here, even when the circumferential length of the heating element sheet is short and a gap is generated between both end portions in the circumferential direction of each power supply unit, the insulating film material is double overlapped via the extended portion. Therefore, even when the pair of electrodes faces the gap of the power supply portion, no discharge is generated between the roller body and the heat of the fixing roller due to the effect of the double-layered insulating film material. Safety and durability can be improved.

In the heat roller for fixing according to the third aspect,
The same effect as that of claim 1 or claim 2 is obtained, but the resistance heating element is constituted by one or a plurality of belt-shaped resistance members meandering in a predetermined meandering pattern, and the pair of power supply portions is connected to a resistance member. Since they are made of the same material, each of the meandering one or a plurality of belt-shaped resistance members is energized through the power supply unit, and can generate heat over the entire area of the fixing heating roller. At this time, the pattern design is facilitated, for example, by forming the meandering pattern into a pattern that generates a larger amount of heat at both ends of the roller body, and the temperature distribution at both ends and the center of the roller body can be freely adjusted. Further, since the power supply portion is made of the same material as the resistance member, the resistance member and the electrode portion can be integrally formed without separately providing ring-shaped electrodes or the like at both ends of the roller body. The electrical contact between the member and the power supply unit is improved.

According to a fourth aspect of the present invention, in the fixing heating roller,
The same effect as in claim 3 is obtained, but the insulating film material includes
Extension portions corresponding to both ends in the circumferential direction of each power supply portion are respectively formed, and each power supply portion is not formed in a portion corresponding to the double overlapped extension portion. Therefore, the thickness of the portion corresponding to the double overlapped extension portion is substantially the same as the sheet thickness of the heating element sheet and has no level difference. When power is supplied, the portions corresponding to these extension portions can be smoothly contacted.

In the heating roller for fixing according to claim 5,
The same operation as in claim 3 is obtained, but the resistance heating element is
Since it is made of a stainless steel foil film, it can be easily manufactured by etching or the like, and can be made lightweight and excellent in durability.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a fixing heat roller incorporated in a fixing mechanism provided in an image recording apparatus such as a copying machine or a printer. Figures 1 and 2
As shown in FIG. 1, the fixing heating roller 10 is in pressure contact with a rubber pressing roller 20, and is rotatably supported by the main body frame by a pivoting mechanism (not shown). The toner adhered on the recording medium P is heated and fixed while being pressed.

The fixing heating roller 10 has an adhesion preventing layer 12 for preventing adhesion of toner on an outer peripheral surface of an aluminum roller body 11 having a good thermal conductivity and having a thickness of about 1 to 3 mm. A resistance heating member 13 composed of a heating element sheet is bonded and fixed to the inner peripheral surface of the roller body 11. The adhesion preventing layer 12 has a thickness of about 10 to 20 μm.
m, which is made of a fluororesin such as Teflon and has excellent heat resistance, and is provided to prevent the toner on the recording medium P from adhering to the surface of the fixing heat roller 10 during the fixing process. Have been. Thus, the adhesion preventing layer 1
2, the toner attached to the surface of the fixing heating roller 10 is transferred to the surface of the pressing roller 20,
Then, it is possible to prevent the toner on the surface of the pressing roller 20 from adhering to the back side of the recording medium P conveyed, thereby preventing the occurrence of contamination.

As shown in FIGS. 2 and 3, the resistance heating member 13 is formed on a surface of an insulating film material 14 made of a polyimide resin film having a thickness of 30 to 50 μm and having heat resistance and insulation properties. It is composed of a flexible heating element sheet on which a resistance heating element 15 having a thickness of 30 to 50 μm and made of two strip-shaped stainless steel foil films meandering in a predetermined meandering pattern is attached. ing.
A left power supply portion 15b and a right power supply portion 15c which are electrically connected to the left and right ends of the resistance member 15a, respectively, are formed integrally at both left and right end portions of the resistance heating element 15, respectively. ing.

Further, as shown in FIG.
The insulating film material 14 corresponding to one end of the circumferential ends of the b and 15c has a predetermined length K for overlapping with the insulating film material end corresponding to the other end. Extension 1
4a is integrally formed in a rectangular shape over the entire width of the resistance heating member 13.

That is, the insulating film material 14 has a lateral dimension W substantially corresponding to the length of the roller body 11 in the roller axis direction, and the length K of the extension 14a is added to the circumferential length S of the roller body 11. In this case, an extension 14a is formed at one end (the lower end in FIG. 3).

As shown in FIG. 1, a pair of left and right conducting electrodes 30 and 31 are respectively supported by the main body frame, and the left conducting electrode 30 slidably contacts the left power supply portion 15b. At the same time, the right energizing electrode 31 slidably comes into contact with the right power feeding portion 15 c, and each resistance member 15 a generates heat by the drive current supplied through these energizing electrodes 30, 31. Heat is efficiently conducted over the entire peripheral surface.

Here, the resistance line width at the left and right end portions of each of the resistance members 15a is formed narrower than the resistance line width at the central portion. That is, since the resistance value at the left and right end portions is large, the heat value at the left and right end portions is configured to be large. Is prevented from lowering, and heat can be generated with a uniform temperature distribution over the entirety of the fixing heating roller 10. Therefore,
Since there is no temperature unevenness in the fixing heat roller 10, an image in a good fixed state can be obtained.

Now, the production of the resistance heating member 13 as the heating element sheet and the attachment of the resistance heating member 13 to the roller body 11 will be described. First, as shown in FIG. 3, a sheet on which a stainless steel foil film is adhered except for a portion corresponding to the extension 14a on the surface of the insulating film material 14 made of a polyimide resin film having electrical insulation properties. A film is prepared, and a resist corresponding to a predetermined meandering pattern for the resistance member 15a and an electrode pattern for the left and right power supply portions 15b and 15c is applied on a stainless steel foil film by screen printing. Then, by removing the resist by etching, a resistance heating member 13 (heating element sheet) having the resistance member 15a and both power supply portions 15b and 15c is manufactured.

Next, a heat-resistant adhesive is applied to the back surface of the insulating film material 14, and the resistance heating element 15 is directed toward the center of the roller body 11 as shown in FIG. 13 is sequentially bonded and fixed to the inner peripheral surface of the roller body 11 from one end provided with the extension portion 14a to the other end (upper end in FIG. 3), and is heated by a high-temperature furnace to generate resistance heat. The member 13 can be easily fixed to the inner peripheral surface of the roller body 11. At this time, even if a power supply portion gap G is generated between both ends of the pair of power supply portions 15b and 15c extending in the circumferential direction of the roller main body 11, the power supply portion gap G is corresponding to the power supply portion gap G.
The insulating film material 14 is doubly overlapped with the extension 14a and the other end of the insulating film material.

Next, the fixing operation of the fixing heating roller 10 will be described. Right and left energizing electrodes 30, 31
The drive current supplied to the power supply units 15b
Each of the resistance members 15a is supplied to the corresponding resistance member 15a via the corresponding one of the resistance members 5a and generates heat. At this time, the resistance line widths at the left and right ends of each resistance member 15a are formed to be narrower than the resistance line width at the central portion thereof, and the amount of heat generated is large.
Since the heating temperature of the fixing heating roller 10, particularly at the left and right ends thereof, is prevented from being lowered, heat can be generated with a uniform temperature distribution over the entire fixing heating roller 10. At this time, each resistance member 15a and both power supply portions 15b,
15c is formed integrally, so that the electrical contact between these resistance members 15a and both power supply portions 15b and 15c is extremely good.

Here, as described above, the roller body 11
Even if a power supply gap G is generated between both ends of a pair of power supply sections 15b and 15c extending in the circumferential direction of the pair, the insulating film material 14 is in contact with the extension 14a corresponding to the power supply gap G. Are overlapped doubly with the end of the insulating film material. Therefore, even when both of the current-carrying electrodes 30 and 31 approach the power supply portion gap G, no discharge occurs between the roller body 11 and the insulating film material 14 overlapped by the double layer. Thus, the safety and durability of the fixing heating roller 10 can be improved.

The heat generated by the resistance heating element 15 is
Adhesion prevention layer 1 via insulating film material 14 and roller body 11
2 is transmitted. Here, the heat generated by the resistance heating element 15 has a more uniform temperature distribution by the roller body 11. Then, the toner attached to the recording medium P conveyed between the fixing heating roller 10 and the pressing roller 20 is heated and fixed on the recording medium P.

As described above, the resistance heating member 13 is provided on the insulating film material 14 with the resistance heating element 15 and the pair of power supply portions 15b, 1
5c, and an insulating film material 14 corresponding to one end of the circumferential ends of each of the power supply portions 15b and 15c, and an insulating film material 14 corresponding to the other end. Since the extension portion 14a for overlapping with the end portion of the insulating film material to be formed is formed, the heating element sheet faces the resistance heating element 15 toward the center of the roller body 11 so that the roller body 1
1 when fixed to the inner peripheral surface of each of the power feeding portions 15b and 15c.
Even if a power supply portion gap G is generated between both ends in the circumferential direction, the portion corresponding to the power supply portion gap G is the insulating film material 14.
Due to the extension 14a and the end of the insulating film material at the other end,
It is doubly overlapped. Therefore, due to the effect of the double-layered insulating film material 14, the current-carrying electrodes 30,
Since no discharge occurs between the roller 31 and the roller body 11, the safety and durability of the fixing heating roller 10 can be improved.

Further, since the resistance member 15a is formed in a meandering pattern, the pattern design becomes easy, for example, in such a pattern as to generate a larger amount of heat at both ends of the roller body 11, so that the both ends of the roller body 11 can be easily formed. And the temperature distribution in the central part can be adjusted freely. In addition, both right and left power supply units 1
5b and 15c are formed continuously with the resistance member 15a, so that the resistance member 15a and the two power supply portions 15b and 15c are integrally formed without separately providing a ring-shaped electrode or the like for supplying power to the resistance member 15a. The electrical contact between the resistance member 15a and the power supply portions 15b and 15c can be extremely improved.

As shown in FIGS. 5 and 6, the resistance heating member 13A is constituted by a heating element sheet in which a resistance heating element 15A is fixed to an insulating film material 14A having two extended portions 14b and 14c. The fixing heating roller 10A may be configured by fixing the resistance heating member 13A to the inner peripheral surface of the roller body 11A. That is, the resistance heating member 13A, which is a heating element sheet, is provided with the resistance heating element 15A and the left and right power supply portions 15d and 15e in the same manner as described above. The insulating film material 14A has a lateral dimension W substantially corresponding to the length of the roller body 11 in the roller axis direction.
Length K of the two extension portions 14b and 14c to the circumference S of
, And has a size corresponding to the vertical dimension L,
One end (the lower end in FIG. 5) has an extension 14b
Is formed, and an extension 14c is formed at the other end (the upper end in FIG. 5).

Then, as shown in FIG.
With the 5A facing the center of the roller body 11A, the resistance heating member 13A is moved from one end provided with the extension 14b to the other end provided with the extension 14c.
By sequentially bonding and fixing the inner peripheral surface of the roller 1A, the resistance heating member 13A can be easily fixed to the inner peripheral surface of the roller body 11. At this time, the power supply unit gap G is provided between both ends of the pair of power supply units 15d and 15e extending in the circumferential direction of the roller body 11.
Even if a gap occurs, the insulating film material 1
The two extension portions 14b and 14c of 4A are positioned so as to overlap with each other. However, the power supply portions 15d and 15e are not formed in portions of the insulating film material 14A corresponding to the two extended portions 14b and 14c that are overlapped.
Two energizing electrodes 30A and 31A are provided at positions shifted by a predetermined phase angle in the circumferential direction of the roller main body 11A, respectively.

Also in this case, similarly to the above-described embodiment, even if a power supply gap G occurs between both ends in the circumferential direction of each of the power supply sections 15d and 15e, a portion corresponding to the power supply gap G is formed. Means that the insulating film material 14A has two extended portions 14b,
14c, the discharge is not generated between the two current-carrying electrodes 30A, 31A and the roller body 11A due to the effect of the double superposed insulating film material 14A. The safety and durability of the fixing heating roller 10A can be improved. Further, since the thickness of the portion corresponding to the doubly overlapped extension portions 14b, 14c is substantially the same as the sheet thickness of the heating element sheet, there is no step between the two, and each of the current-carrying electrodes 30A, 31A has When the power is supplied by slidingly contacting the power supply portions 15b and 15c, the portions corresponding to the extension portions 14b and 14c can be smoothly contacted.

On the other hand, as shown in FIG. 7, the resistance heating member 13 composed of the heating element sheet shown in FIG. 3 is placed on the outer periphery of the roller body 11B with the resistance heating element facing the outside of the roller body 11B. Fixing heating roller 10B fixed to the surface
And each of the power supply portions 15b, 1 formed on the heating element sheet
5c may be configured to be energized from the outside via the energizing electrodes 30B and 31B. Here, the resistance heating member 1
An adhesion preventing layer made of a fluororesin or the like may be formed on the surface of the three except for the power supply parts 15b and 15c, as in the above-described embodiment. Again, in this case,
The fixing operation is performed in the same manner as in the above-described embodiment, and the same effect can be obtained.

Further, as shown in FIG. 8, the resistance heating member 13A composed of the heating element sheet shown in FIG. 5 is placed in a state where the resistance heating element 15 faces the outside of the roller body 11C.
The fixing heating roller 10C is fixed to the outer peripheral surface of the roller body 11C, and each of the power supply portions 15 formed on the heating element sheet is formed.
A current may be supplied to the electrodes d and 15e from outside through the electrodes 30C and 31C. Here, an adhesion preventing layer made of a fluororesin may be formed on the surface of the resistance heating member 13A except for the power supply portions 15b and 15c, as in the above-described embodiment. In this case, the fixing operation can be performed in the same manner as in the above-described modified embodiment, and the same effect can be obtained.

The meandering pattern may be configured to change the density of the resistance member 15a formed in a unit area. It should be noted that various modifications may be made to the above-described embodiment based on existing technology or technology obvious to those skilled in the art without departing from the technical spirit of the present invention.
Of course, the present invention can be applied to various types of fixing heating rollers provided with a roller body and a resistance heating member and used in a fixing mechanism provided in an image recording apparatus such as a copying machine or a facsimile.

[0039]

According to the heat roller for fixing of the first aspect,
The resistance heating member is constituted by a heating element sheet in which a resistance heating element and a pair of power supply portions are fixed on an insulating film material, and at least one end of both circumferential end portions of each power supply portion. In the insulating film material corresponding to the portion, an extension portion for overlapping with the end portion of the insulating film material corresponding to the other end is formed, so that the heating element sheet has the resistance heating element in the center of the roller body. When it is fixed to the inner peripheral surface of the roller main body in a state facing the side, the insulating film material is double overlapped via the extension at the positions of both ends of the pair of power supply units.

Therefore, even when the circumferential length of the heating element sheet is short and a gap is generated between both ends in the circumferential direction of each of the power supply sections, the insulating film material is superimposed twice via the extension section. Therefore, when each electrode is slidably contacted with the power supply section and is energized, each electrode does not discharge with the roller body due to the double-layered insulating film material, and is used for fixing. The safety and durability of the heating roller can be improved.

According to the fixing heating roller of the second aspect, the resistance heating member is constituted by a heating element sheet in which a resistance heating element and a pair of power supply sections are fixed on an insulating film material. Since the insulating film material corresponding to at least one of the two ends in the circumferential direction of the power supply portion has an extended portion for overlapping with the insulating film material end corresponding to the other end, ,
When the heating element sheet is fixed to the outer peripheral surface of the roller body with the resistance heating element facing the outside of the roller body, the insulating film material is provided via the extension at the positions of both ends of the pair of power supply sections. It is doubly overlapped. Therefore, the same effect as the first aspect can be obtained.

According to the fixing heating roller of the third aspect, the same effect as in the first or second aspect is obtained, but the resistance heating element has one or a plurality of belt-shaped resistances meandering in a predetermined meandering pattern. Since the pair of power supply units are formed of the same material as the resistance member, each of the meandering one or more belt-shaped resistance members is energized through the power supply unit,
Heat can be generated over the entire area of the fixing heating roller. At this time, the pattern design is facilitated, for example, by forming the meandering pattern into a pattern that generates a larger amount of heat at both ends of the roller body, and the temperature distribution at both ends and the center of the roller body can be freely adjusted. Further, since the power supply portion is made of the same material as the resistance member, the resistance member and the power supply portion can be integrally formed without separately providing a ring-shaped electrode or the like. Good electrical contact.

According to the heat roller for fixing of the fourth aspect, the same effect as the third aspect is obtained, but the insulating film material has extension portions corresponding to both ends in the circumferential direction of each power supply portion. Since each power supply section is not formed at a portion corresponding to the double overlapped extension, the thickness of the portion corresponding to the double overlapped extension is determined by the sheet thickness of the heating element sheet. Since there is no step because the electrodes are slidably contacted with the power supply unit, the portions corresponding to the extended portions can be smoothly contacted.

According to the fixing heating roller of the fifth aspect, since the resistance heating element is made of a stainless steel foil film, it can be easily manufactured by etching or the like, and is lightweight and has excellent durability. Can be.

[Brief description of the drawings]

FIG. 1 is a partially cutaway schematic perspective view of a heating roller for fixing.

FIG. 2 is a vertical sectional front view of a main part of a fixing heating roller.

FIG. 3 is an exploded plan view of a resistance heating member having one extension formed thereon.

FIG. 4 is a side view of a longitudinal section of a main part of a fixing heat roller.

FIG. 5 according to a variant, with two extensions formed;
FIG.

FIG. 6 is a diagram corresponding to FIG. 4, in which a resistance heating member having two extended portions is provided on an inner peripheral surface of a roller body according to a modified embodiment.

FIG. 7 is a diagram corresponding to FIG. 4, in which a resistance heating member having one extension portion is provided on an outer peripheral surface of a roller body according to a modified embodiment.

FIG. 8 is a view corresponding to FIG. 4, in which a resistance heating member having two extended portions is provided on an outer peripheral surface of a roller body according to a modified embodiment.

[Explanation of symbols]

 10, 10A to 10C Heating roller for fixing 11, 11A to 11C Roller body 13, 13A Resistance heating member 14, 14A Insulating film material 14a to 14c Extension 15, 15A Resistance heating element 15a Resistance member 15b, 15d Left power supply portion 15c, 15e Right side power supply part 30, 30A-30C Conducting electrode 31, 31A-31C Conducting electrode

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 13/20 G03G 15/20 G03G 21/20 H05B 3/00 335 H05B 3/20 341

Claims (5)

(57) [Claims] 1. A roller body formed in a cylindrical shape, a resistance heating member provided on an inner peripheral surface of the roller body and generating heat by energization, and a roller for slidingly contacting and energizing the resistance heating member. A heating roller for heating and fixing toner adhered to a recording medium conveyed in contact with the outer peripheral surface of the roller body, wherein the resistance heating member includes an insulating film. And a pair of belt-shaped power supply portions corresponding to both ends of the roller body and extending in the circumferential direction of the roller body, the pair of power supply portions being electrically connected to the resistance heat body. Insulating film material corresponding to at least one end of the circumferential ends of each power supply unit is provided with an insulating film material end corresponding to the other end. An extension is formed to overlap the part, and the heating element sheet is The resistance heating element is fixed to the inner peripheral surface of the roller body with the resistance heating element facing the center of the roller body. Further, at the positions of both ends of the pair of power supply sections, the insulating film material is doubled via the extension section. A heating roller for fixing, which is superposed on the fixing roller. 2. A roller body formed in a cylindrical shape, a resistance heating member provided on an outer peripheral surface of the roller body and generating heat by energization, and a roller for slidably contacting the resistance heating member and energizing the roller. A fixing heating roller including a pair of electrodes for heating and fixing toner adhered to a recording medium conveyed in contact with an outer peripheral surface of the roller body, wherein the resistance heating member is an insulating film material A resistance heating element, and a pair of belt-shaped power supply sections corresponding to both ends of the roller body and extending in the circumferential direction of the roller body, and a pair of power supply sections electrically connected to the resistance heating element; The insulating film material corresponding to at least one end of the circumferential ends of each power supply unit has an insulating film material end corresponding to the other end. An extension is formed to overlap the heating element sheet. The resistance heating element is fixed to the outer peripheral surface of the roller body with the resistance heating element facing the outside of the roller body.
A heating roller for fixing, characterized in that insulating film materials are double overlapped via extension portions at positions at both ends of the pair of power supply portions. 3. The resistance heating element includes one or a plurality of belt-shaped resistance members meandering in a predetermined meandering pattern, and the pair of power supply portions is formed of the same material as the resistance member. The heating roller for fixing according to claim 1 or 2, wherein 4. An extension portion corresponding to each circumferential end portion of each power supply portion is formed in the insulating film material, and each power supply portion is formed at a portion corresponding to a double overlapped extension portion. 4. The fixing heat roller according to claim 3, wherein the heat roller is not fixed. 5. The fixing heat roller according to claim 3, wherein the resistance heating element is made of a stainless steel foil film.