JPH11327343A - Heating roller and thermal fixing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make heat generated in a heating element transmitted to a roller main body even in the case of restraining the use of an expensive adhesive by using a barrel body obtained by joining both sides of a square thin layer body having a rigidity and fixing it in a cylindrical shape as an insulating layer. SOLUTION: The insulating layer is formed of a hard calcined mica sheet 25, and a stainless foil is fixed as an energizing heating element 28 nearly all over the surface of a plane part 26 with a small quantity of heat resistant adhesive. The mica sheet 25 is formed to be the cylindrical shape by super posing an upper edge 26a inside a lower edge 26b. At such a time, a U-turn part 26a is held by the superposed part. A long piece part 27 is turned inside and fixed on the inner surface of the superposed part with the silicone based adhesive. Thus, a U-turn part 28b is coated with the long piece part 27 through the adhesive. By coating the U-turn parts 28a and 28b, a cylindrical barrel body, where the U-turn parts 28a and 28b are not peeled even when the barrel body is used for a long term, is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a heating roller and a fixing device used in an image forming apparatus such as a copying machine, a printer, and a facsimile.

[0002]

2. Description of the Related Art As a fixing method of a toner image in electrophotography, a heat fixing method, a pressure fixing method, a solvent fixing method and the like are known. The heat fixing method is a method in which toner is melted by heat and pressure is applied to paper to fix the paper, and is generally widely used.

In this heat fixing method, a developed image is formed by using a heat fixing device including a heating roller and a pressure roller, and a printing paper on which toner is transferred and developed is formed by a heating roller and a pressure roller. The toner for forming an image is heated and melted, and is fused and fixed on the printing paper by this. Here, as the heating roller, a method of heating from the inner surface of a metal roller with radiant heat of a halogen lamp is most widely used.

[0004] Such a method of heating with a halogen lamp has a problem that thermal efficiency of energy is poor and power consumption is increased. Further, in the heat fixing method using such a halogen lamp, the time from when the power of the apparatus is turned on until the temperature reaches a usable temperature, that is, the so-called rise time is 2 hours.
It generally takes 5 seconds or more. For this reason, the temperature is always kept at a certain level or higher even when the apparatus is not used, so that there is no waiting time until the heating roller becomes hot when copying or printing out.

In recent years, in these heat fixing apparatuses, the power supply to the heating roller is cut off when not in use for the purpose of reducing power consumption. On the other hand, there is no waiting time during use, and an instant rise is required, and the surface temperature of the heating roller is required to immediately reach a predetermined temperature. In this case, the time required for the printing paper to move to the fixing unit is usually 7
Since the time is about seconds, the time required for the heating roller to reach the predetermined temperature is about 10 seconds.

With the trend of energy saving in recent years, a film fixing device that generates heat only when the apparatus is used by using a film instead of a heating roller has been proposed and put into practical use. However, in the case of a device having a high paper passing speed, there is a problem in the abrasion resistance of the film and the like. Therefore, the heating roller is superior in a device having a high paper passing speed.

The present inventors have developed a heating and fixing apparatus having a heating roller with a short rise time, in which a heating layer that generates heat when energized is inscribed in a hollow cylindrical base via an insulating layer. Laura proposed. In this heating roller, the heat generated by the heat generating layer is directly transmitted to the base, so that the surface temperature rises to a predetermined temperature in a shorter time compared to, for example, a method in which a roller is radiatively heated by a halogen heater which has been widely used in the past. Can be done.

[0008]

However, in this heating roller, if the contact of the joint surface between the core metal and the insulating layer and the heat generating layer rises or is poor, the heat generated by the heat generating layer is transferred to the core metal. The transmitted heat transfer coefficient decreases. For this reason, it is preferable that the core metal, the insulating layer, and the heat generating layer are bonded with, for example, a heat-resistant adhesive. The adhesive must withstand high heat, but such an adhesive with high heat is expensive.

Even when the inner surface of the roller and the insulating layer and the insulating layer and the heat generating layer are bonded to each other, the heat generating layer may float over the insulating layer over time due to a difference in heat shrinkage during use of the fixing roller. When the heat generating layer floats above the insulating layer, heat conduction to the roller is deteriorated only at that portion, and heat is generated at a high temperature. As a result, the insulating layer and the heat generating layer themselves may be destroyed, resulting in leakage or disconnection.

Accordingly, a first object of the present invention is to provide a heating roller in which heat generated by a heating element is transmitted to a roller body even when the use of an expensive adhesive is suppressed, and a fixing device using the same. It is in. Another object of the present invention is to
An object of the present invention is to provide a heating roller that suppresses destruction of the insulating layer and the heating layer itself. Thus, an inexpensive heating roller having a high heat transfer coefficient and a fixing device using the same can be provided.

[0011]

According to a first aspect of the present invention, there is provided a heating roller in which a heat generating layer which generates heat when energized is inscribed in a hollow cylindrical base via an insulating layer. Is a heating roller characterized by using a cylindrical body in which both sides of a rigid thin layered body are fitted together and fixed in a cylindrical shape.

[0012] In the heating roller according to the first aspect of the present invention, a cylindrical insulating layer formed by fixing both sides of a rigid rectangular thin body is provided inside the heating roller. Since the insulating layer is not in contact with the heating roller and does not float due to the rigidity of the material itself, the cylindrical shape can be maintained even if the insulating layer and the base are not bonded by the adhesive. Thus, even if the amount of the adhesive used for fixing is suppressed, the heat generating layer is in close contact with the inner periphery of the heating roller, and the heat of the heat generating element can be efficiently transmitted.

The invention according to claim 2 is characterized in that the mating portion is fixed by an engaging tongue formed so as to protrude from one side of the plate-like thin layer body. It is a heating roller as described.

According to the second aspect of the present invention, the mating portion is fixed by the engaging tongue. Thereby, since the mating portion is reinforced, the effect of the first aspect that the insulating layer keeps the cylindrical shape and the floating of the insulating layer can be prevented is ensured.

According to a third aspect of the present invention, the mating portion has an engaging tongue formed on one side of the flat thin-layer body and an engaging hole formed on the other side opposite to the one side. The heating roller according to claim 1, wherein the heating roller is fixed by fitting with the heating roller.

According to the third aspect of the present invention, the mating portion is fixed by the engagement between the engagement tongue and the engagement hole. Thereby, since the mating portion is reinforced, the effect of the first aspect that the insulating layer keeps the cylindrical shape and the floating of the insulating layer can be prevented is ensured.

According to a fourth aspect of the present invention, the engaging tongue piece is fixed by sandwiching a heating element forming the heating layer therebetween. It is a heating roller.

According to the fourth aspect of the present invention, since the heating element is sandwiched by the engaging tongues, the heating element is prevented from floating.

According to a fifth aspect of the present invention, there is provided a heating roller in which a heating element which generates heat when energized is inscribed in a hollow cylindrical base via an insulating layer, wherein the heating element is provided at a center side of the heating element. A heating roller is provided, which is provided with a support for supporting the heating element, the heating element being supported by the support.

In the heating roller according to the fifth aspect of the present invention, the insulating layer and the heat generating layer are superposed on the inside of the base, and the heat generating element constituting the heat generating layer is located on the center side of the heat generating element. Is supported by a support provided on the substrate. This allows the heating layer to be polymerized and supported without being bonded to the insulating layer, so that the insulating layer is not broken or floated by thermal stress based on the difference in linear expansion coefficient between the insulating layer and the heating layer. In addition, since the heat generating layer can be supported without using an adhesive, the heat generating layer can be in close contact with the inner periphery of the heating roller and efficiently transfer heat of the heat generating element without using an adhesive for supporting. it can.

The support of the heating element on the support has, for example, at least one notch in the support, and a part of the heating element is supported by being locked to the notch. You can also.

Also, as in the invention of claim 7, claim 6
By forming the heating element of the heating roller described in (1) in a sheet shape having a portion inserted into the notch, the inserted portion can be inserted into the notch and supported by the support.

Further, as in the eighth aspect of the present invention, the heating element may be provided with a folded portion capable of holding the support by folding, and the heating element may be sandwiched by the folding by the folded portion. In this case, the folded portion may be held at any position as in the invention dependent on claim 5, but as in the invention dependent on claim 6, the support is fixed by being sandwiched by the notch. Further, as in the invention according to the seventh aspect of the present invention, the insertion part provided in the heating element is inserted into the notch, and the insertion part is turned back, so that the reliability is further improved.

According to a ninth aspect of the present invention, the support has an engagement hole, and the heating element has a locking portion fitted in the engagement hole. 6. The heating roller according to claim 5, wherein the heating element is fixed to the support body by fitting.

With this configuration, the heating element is supported by fitting to the support, so that the heating element can be securely fixed.

The heating roller according to any one of the first to ninth aspects may have a release layer on the outer surface of the heating roller as in the tenth aspect.

The invention described in claim 11 is the first invention.
11. A heating roller, comprising: a heating roller according to any one of claims 10 to 10; and a pressure roller rotatably pressed against the heating roller. This is a heat fixing device for fusing.

The heating roller according to any one of claims 1 to 10 can be used as a heat fixing device by being combined with a pressure roller.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the present invention will be described below with reference to the drawings, taking as an example a heat fixing device comprising a heating roller and a pressure roller.

In FIG. 1, reference numeral 1 denotes a heat fixing device. The heat fixing device 1 is generally constituted by a heating roller 2 and a pressure roller 3 provided in parallel with the heating roller 2.
Both ends of the heating roller 2 are rotatably supported by a pair of heating roller bearings 4. A drive gear 5 is disposed on one side of the heating roller bearing 4. Its drive gear 5
Is driven by a motor (not shown) to
Is rotated. The pressure roller 3 is rotatably supported at both ends by pressure roller bearings 6. The heating roller 2 pinches the printing paper while rotating together with the pressure roller 3. The toner is transferred to the printing paper. The toner is heated and melted by passing between the rollers 2 and 3 and is fixed on the printing paper. The heat fixing device 1 includes members necessary for the heat fixing device, such as a cleaning member for cleaning toner adhered to the pressure roller 3 (both are not shown).
Is provided.

The heating roller 2 has a base 21 made of hollow cylindrical aluminum having a diameter of 30 mm and a length of 370 mm. On the surface of the substrate 21, a release layer 22 for improving the releasability from the printing paper is provided. The release layer 22 is, for example, a heat-shrinkable tube made of a perfluoroalkoxy resin (PFA resin). An insulating layer 23 is inscribed on the inner surface of the base 21, and a heat generating layer 24 is provided on the insulating layer 23. Base 21
This layer is unnecessary when the layer has a release property.

A detailed example of the insulating layer 23 and the heat generating layer 24 is as follows.
For example, it is shown in FIGS. 2, the insulating layer 23 is formed from a hard fired mica sheet 25. The mica sheet 25 has a rectangular flat portion 26 composed of an upper edge 26a, a lower edge 26b, and both side edges 26c and 26d, and extends from one side edge 26c at a length substantially equal to the length of the lower edge 26b. And a long piece 27 of a rectangle.

On the surface of the flat portion 26, a stainless steel foil (SUS30) as an electric heating element 28 is provided over almost the entire surface.
4) is fixed by a small amount of heat-resistant adhesive (not shown). The energizing heating element 28 has an upper edge 26a and a lower edge 26b.
U-turn portions 28a and 28b are provided in the vicinity, and are formed in a continuous linear pattern from one side edge 26c to the other side edge 26d. The pattern of the energizing heating element 28 is not limited to this and can be freely designed according to the purpose.

As shown in FIG. 3, the mica sheet 25 has a cylindrical shape formed by superimposing the upper edge 26a inside the lower edge 26b. At this time, the U-turn portion 26a is sandwiched between the overlapping portions 29. On the inner surface of the overlapping portion 29, a long piece 2
7 is folded inward and fixed with a silicone adhesive or the like. As a result, the U-turn portion 28b is covered with the long piece portion 27 via the adhesive. By covering the U-turn portions 28a and 28b in this way, even if the U-turn portions 28a and 28b are used for a long time,
Thus, a cylindrical tubular body 30 from which the a and b do not peel off is formed.

As shown in FIG. 4, the cylindrical body 30 is inserted inside the base 21 provided with the release layer 22. Next, the overlapping portion 29 of the cylindrical body 30 and the base 2
1 is adhered and fixed to the inner surface. A pair of disc-shaped (cap-shaped) electrodes 7 made of nickel plated aluminum;
7 ′ is pressed into the inside of the heat generating layer 24. As a result, the electrodes 7, 7 'are fixed in a state of being electrically connected to the current-carrying heating element 28. When a predetermined power is supplied from a power supply (not shown) to the electrodes 7 and 7 ', the energizing heating element 28 generates heat, and the temperature of the heating roller rises.

In this heating roller, the power transmission to the heat generating layer is performed by sliding the fixed electrode on a disk-shaped rotating electrode which is internally fixed to the heat generating layer and rotates with the rotation of the heating roller.
With this configuration, since power is transmitted inside the cylindrical body, stable power can be transmitted for a long time without causing toner adhesion.

The heating roller produced in this manner was incorporated into a real machine as a fixing roller of a copying machine manufactured by Ricoh Co., Ltd., and a fixing test was conducted. At this time, the surface temperature of the heating roller is around 190 ° C. In the paper passing test of 100,000 sheets, no peeling or lifting of the insulating layer from the cored bar was observed.

In this embodiment, stainless steel foil is used as the current-generating heating element. However, as long as the effect of the present invention is not impaired, the material may be converted to another material such as using carbon fiber as the current-generating heating element. Is also good. In addition, the heat generating layer is, for example, impregnated with a heat-resistant resin in a state in which a linear energizing heat generating element is arranged in a spiral or linear manner in the roller axis direction linearly without any gap, or other insulating layers such as an inner layer. The layers may be stacked.

The present invention can also be applied to a heating roller of a thermochromic heating / erasing device, and a heating / fixing device used in other heat roller type heat treatment equipment.

[0040]

Embodiment 2 Embodiment 2 of the present invention will be described with reference to FIG. Note that the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the mica sheet 25 according to the second embodiment, a substantially rectangular tongue piece 31 as an engaging tongue piece is formed so as to protrude from the upper edge 26a of the flat part 26. An opening 32 is formed near the lower edge 26b at a position corresponding to the tongue piece 31. Further, a stainless steel foil (SUS304) as a current-carrying heating element 28 is fixed to the surface of the flat portion 26 over substantially the entire surface in the same manner as in the first embodiment.

As shown in FIG. 6, the length d1 of the tongue piece 31 is equal to the distance d2 between the opening 32 and the U-turn part 28b.
It is formed sufficiently longer than the distance d3 between the opening 32 and the lower edge 26b. The distance d3 between the opening 32 and the lower edge 26b is sufficiently larger than the distance d4 between the U-turn part 28a and the upper edge 28a.

As shown in FIGS. 7 and 8, the mica sheet 25 has a cylindrical body 30 formed by inserting the tongue piece 31 from the inside of the opening 32 to the outside. The overlapping portion 29 near the upper edge 26a and the lower edge 26b of the insulator, and the tongue piece 31 and the flat portion 26 are fixed by the same silicone adhesive as in the first embodiment. A heating roller is formed by incorporating electrodes in the same manner as in the first embodiment.

The heating roller produced as described above was incorporated in a real machine as a fixing roller of a copying machine manufactured by Ricoh Co., Ltd., and a fixing test was performed. No peeling or lifting of the insulating layer from the cored bar was observed. (Modification 1) As shown in FIG. 9, the tongue piece 31 may be folded back. In this case, if the length d1 of the tongue piece 31 is sufficiently longer than the distance d3 between the opening 32 and the lower edge 26b, the tongue piece 31 becomes longer than the width of the overlapping portion 29. Since the piece 31 can be bonded and fixed across the lower edge 26b, the fixing with the adhesive is ensured. (Modification 2) Further, the mica sheet 25 is
1 can be inserted from the outside of the opening 32. Thereby, the cylindrical body 30 as shown in FIG. 10 is formed.

Here, the length d1 of the tongue piece 31 is equal to the opening 3
11 is sufficiently longer than the distance d2 between the U-turn part 28b and the U-turn part 28b, and as shown in FIG.
1 through an adhesive. Opening 3
2 and the lower edge 26b are sufficiently wider than the distance d4 between the U-turn portion 28a and the upper edge 28a.
8a is covered by an overlapping part via an adhesive.
The tongue piece 31 and the overlapping portion 29 of the mica sheet 25
It is fixed with the same silicone adhesive as in the first embodiment.

The heating roller thus manufactured was incorporated in a real machine as a fixing roller of a copying machine manufactured by Ricoh Co., Ltd. in the same manner as in Embodiment 2, and a fixing test was performed. No peeling or lifting of the insulating layer from the cored bar was observed. Further, since the U-turn portions 28a and 28b are covered with the mica sheet 25, the U-turn portions 28a and 28b do not peel off even after long-term use.

[0047]

Third Embodiment A third embodiment of the present invention will be described with reference to FIG. Embodiment 2
The same or equivalent parts are denoted by the same reference numerals, and detailed description is omitted.

The tongue piece 31 of the second embodiment is similar to that of FIG.
As shown in FIG. 2, the tongue piece 33 may be a parallelogram. A heating roller was manufactured and a paper-passing test was performed in the same manner as in Embodiment 2 except that a mica sheet having such a tongue piece 33 was used. I couldn't.

By inserting the tongue piece 33 through the opening 32 in this way, the cylindrical body 30 is formed without using an adhesive. A heating roller prepared by applying an adhesive only to the overlapping portion and fixing the core to a cored bar was incorporated into a real machine as a fixing roller of a copying machine manufactured by Ricoh Co., Ltd., and a fixing test was performed. No peeling or lifting of the insulating layer from the cored bar was observed. (Modification 3) As shown in FIG. 13, the tongue piece 34 has a tip whose width is wider than the root. in this case,
By inserting the tongue piece 34 into the opening 32, the cylindrical body 30 is formed without using an adhesive. A heating roller prepared by applying an adhesive only to the overlapping portion and fixing the core to a cored bar was incorporated into a real machine as a fixing roller of a copying machine manufactured by Ricoh Co., Ltd., and a fixing test was performed. As in the third embodiment, no peeling or lifting of the insulating layer from the metal core was observed. (Comparative Example 1) For comparison, as shown in FIG. 14, a heating roller was similarly formed using a mica sheet 25 having no long piece 27 or tongue piece provided with a similar energizing heating element 28. Produced. The bonding between the core metal and the insulating layer was performed by applying the same silicone adhesive as in the first embodiment to the entire surface of the insulating layer. Next, a paper passing test similar to that of the first embodiment was performed.
In order to prevent the insulating layer from being peeled off or lifted from the core metal, the adhesive with the core metal required an adhesive 20 times or more as compared with the heating roller of the first embodiment. This confirms that according to the embodiment of the present invention, the amount of the adhesive used can be extremely suppressed. (Comparative Example 2) For another comparison, in Comparative Example 1, the bonding between the core metal and the insulating layer was performed at the overlapping portion (overlapping portion) of the insulating layer.
Only 29 was coated with a silicone adhesive and used. The same paper passing test as in Example 1 was performed. After 10,000 sheets were passed, the overlapped portion 29 of the insulating layer was peeled off, and local lifting was recognized between the core metal and the insulating layer. As a result, the heat transfer coefficient from the heat generating layer to the substrate was reduced, and the rise time as a fixing device was delayed.

As described above, in the overlapping portion 29 of the insulating layer, the adhesive is often peeled off and floated due to a large thermal stress due to the operation of the fixing device. Is fixed so that it does not peel off.

[0051]

Fourth Embodiment A fourth embodiment of the present invention will be described with reference to FIG. Embodiment 1
The same or equivalent parts as those of Nos. 1 to 3 are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 15, reference numeral 2 denotes a heating roller. The heating roller 2 includes a hollow cylindrical aluminum base 21 and a release layer 22 formed on the surface of the base 21.
And an insulating layer 2 bonded to the inner surface of the base 21 with an adhesive.
3, a heat generating layer 24 insulated from the base 21 by the insulating layer 23, and a cylindrical support 35 supporting the heat generating layer 24.
The heat generating layer 24 is engaged with a notch provided in the cylindrical support 35 as described below.

Next, the configuration of the heating roller 2 will be described in detail in accordance with the assembly process.

As shown in FIG. 16, the cylindrical support 35 is formed with a molded sheet 36 such as a mica sheet (mica sheet for molding) having a thickness of about 1 mm.
Formed from This sheet 36 has an upper edge 36a and a lower edge 3
6b, a rectangular sheet composed of both side edges 36c and 36d, and four parallel to the edges 36a and 36b.
The book (two pairs) has notches 37 (ad).

On the other hand, the heating element 38 constituting the heating layer 24
As shown in FIG. 17, for example, is a stainless steel foil formed in a square planar sheet shape by a continuous zigzag linear pattern from one side edge 38a to the other side edge 38b, and has an upper edge and a lower edge thereof. Has a U-turn section 39
(39a, 39b) are formed.

As shown in FIG. 18, the heating element 38
The U-turn portions 39 are inserted into the cuts 37 so as to be sewn, so that the U-turn portions 39 are superposed on the sheet 36 and supported.

That is, the U-turn part 39a is
Is inserted into the cut 37b from the front side (the insulating layer 23 side) of the sheet 36 and protrudes to the back side of the sheet 36 (the center side of the base).
Next, the U-turn portion 39a is cut 37 from the back side.
and is projected again to the front side. Similarly, the U-turn portion 39b is inserted into the notch 37c from the front side and protrudes from the back surface of the sheet 36, and then the U-turn portion 39b is inserted into the notch 37d from the back side and the U-turn portion 39b is again It protrudes to the surface side. As a result, as shown in FIG. 18B, the heating element 38 is inserted into the cut 37 from the front side, and a part thereof is inserted and sewn to the rear side (the center side of the base). Portions 39c and 39d are formed. The heating element 38
Is exposed to the surface of the sheet 36 by being superposed on the sheet 36.

FIG. 19 shows a state in which the insulating sheet or film (insulating sheet 40) constituting the insulating layer 23 is further superposed on the lowermost portion of the sheet 36 on the heating element 38 side.
As shown in (1), it is wound around a thermally expandable mandrel 41. As shown in FIG. 20, the mandrel 41 has a configuration in which the core metal 41 a is covered with the silicon rubber 41 b, so that the coefficient of thermal expansion is larger than that of the base 21.

The surface 40a of the insulating sheet 40 is
As shown in (2), a silicone-based heat-curable adhesive is applied. Next, the mandrel 41 wound around the sheet 36 is inserted into a predetermined position inside the base 21 having the release layer 22. Rollers are placed in an electric furnace (not shown) for 180
Heat at ° C for 1 hour. By this heating, the insulating layer 23 is adhered to the inner surface of the base 21 because of the thermosetting property of the adhesive. Further, a sheet 36 serving as a support is also formed into a cylindrical shape to form a cylindrical support 35, and the heating element 38 is pressed against the insulating layer 23 by the cylindrical support 35.

Next, when the mandrel 41 and the like are cooled to room temperature, only the mandrel 41 is pulled out of the base 21. By inserting a pair of disc-shaped electrodes 7 and 7 ′ into the inside of the heat generating layer 24 at both ends of the base 21, the electrodes 7 and 7 ′ are formed.
Is fixed in a state where it is electrically connected to the current-carrying heating element 38, the heating roller 2 shown in FIG. 15 is obtained. When a predetermined power is supplied to the electrodes 7 and 7 ′ from a power supply (not shown), the heat generating layer 24 as the current-generating heating element generates heat, and the temperature of the heating roller 2 is increased.

The heating roller thus manufactured is
It is used by being incorporated in a fixing device and repeating a heat cycle of heating and cooling. At this time, the heating layer 24
The insulating layer 23 and the insulating layer 23 repeat thermal expansion and contraction of thermal expansion and contraction. However, since the adhesive is not used for the heat generating layer 24 and the insulating layer 23, the thermal expansion and contraction indicated by the arrows as shown in FIG. Even if this occurs, the insulating layer 23 does not break or float due to the thermal expansion and contraction of the heat generating layer 24.

The heating roller manufactured in this manner is incorporated in a fixing device, and is heated to room temperature (26 ° C. or less) -220 ° C.
When a heat cycle was performed at room temperature as one cycle, heat generation was possible without breaking the insulating layer even after 100,000 cycles.

On the other hand, if the heat generating layer is fixed with an adhesive, the heat generating layer adhered in 50,000 cycles is peeled off from the insulating layer.

Thus, in the heating roller according to the fourth embodiment, since the heating layer 24 is not completely adhered to the insulating layer 23, the rising time is delayed by several seconds as compared with the conventional heating roller, but the halogen having the same power consumption is generated. The rising speed was remarkably faster than that of a heat roller using a lamp. (Modification 4) In the heating roller according to Embodiment 4, FIG.
8 (a) and 8 (b), some of the sewn portions 39c,
Since 39d is arranged on the back surface side (the center side of the base), there is a concern that heat conduction to the base 21 near the sewn portions 39c and 39d may be delayed. In such a case, FIG.
As shown in FIG.
On the other hand, as shown in FIG. 24, the heating element 38 may be provided with insertion portions 43 provided at both end edges outside the U-turn portions 39a and 39b in the insertion direction. When the insertion portion 43 is inserted into the cut 42, the insertion portion 43 is fitted into the cut 42, and the heating element 38 can be fixed to the sheet 36, as shown in FIG. As shown in FIG. 26, the insertion portion 43 is folded back so as to sandwich the sheet 36 after being inserted into the notch 42 of the sheet 36 as a support, so that the heating element 38 is
More securely. As a result, the heating element pattern on the front side after the heating element 38 is inserted can be removed without providing the sewing portions 39c and 39d arranged on the back side.
8 can be fixed to a sheet 36 as a support.

As shown in FIG. 27, the insertion portion 43 is formed by extending an orthogonal portion 43 extending in a direction orthogonal to the insertion direction.
By forming a, by providing a hook-shaped (or key-shaped) locking portion that is locked to the cut 42, the heating element 38 is more securely fixed to the support 37 without using an adhesive. It becomes possible. With this configuration, even when a force that pulls out the heat generating layer after the insertion is applied to the portion inserted into the support, the heating element is prevented from being pulled out of the support by the action of the orthogonal portion 43a. You. The orthogonal portion 43a, together with the insertion portion 43, is folded back toward the insulator as necessary, so that it is more securely fixed as shown in FIG.

As described above, even if the fixing is securely performed, the heating element 38 is not fixed to the insulating layer 23 by adhesion, so that it is free from slight expansion and contraction due to thermal expansion and contraction. It is completely the same as the embodiment that the insulating layer 23 does not break or float due to the expansion and contraction of the heating element 38.

[0067]

As described above, according to the first aspect of the present invention, the insulating layer is inscribed in the heating roller due to the rigidity of the material itself and does not float, so that the insulating layer and the base are bonded. Even if they are not adhered by the agent, the cylindrical shape can be maintained. Thus, even if the amount of the adhesive used for fixing is suppressed, the heat generating layer is in close contact with the inner periphery of the heating roller, and the heat of the heat generating element can be efficiently transmitted.

According to the second aspect of the present invention, since the mating portion is fixed by the engaging tongue and the mating portion is reinforced, the insulating layer maintains a cylindrical shape, and the insulating layer can be prevented from floating. Is assured.

According to the third aspect of the present invention, the mating portion is fixed by the engagement between the engaging tongue and the engaging hole to reinforce the mating portion. The effect of claim 1 that the floating can be prevented is ensured.

According to the fourth aspect of the present invention, since the heating element is sandwiched by the engaging tongue pieces, the lifting of the heating element is prevented.

According to the fifth aspect of the present invention, the insulating layer and the heat generating layer are superposed on the inside of the base, and the heat generating element constituting the heat generating layer is formed by the support provided on the center side of the heat generating element. Since the heat generating layer is supported, the heat generating layer can be supported without being bonded to the insulating layer by polymerization. Does not occur. In addition, since the heat generating layer can be supported without using an adhesive, the heat generating layer can be in close contact with the inner periphery of the heating roller and efficiently transfer heat of the heat generating element without using an adhesive for supporting. it can.

The support of the heating element on the support has, for example, at least one notch in the support, and a part of the heating element is supported by being locked to the notch. You can also.

Further, as in the invention of claim 7, claim 6
By forming the heating element of the heating roller described in (1) in a sheet shape having a portion inserted into the notch, the inserted portion can be inserted into the notch and supported by the support.

Further, as in the eighth aspect of the present invention, the heating element may be provided with a folded portion capable of holding the support by folding, and the heating element may be sandwiched by the folding by the folded portion. In this case, the holding position of the folded portion may be any position as in the invention dependent on the fifth aspect of the invention. Further, the holding position may be fixed by being cut by notches as in the invention according to the sixth aspect of the invention, or the heating element may be fixed as in the invention according to the seventh aspect of the invention. By inserting the insertion portion provided in the notch into the notch and turning the insertion portion back, the reliability is further improved.

According to the ninth aspect of the present invention, since the heating element is supported by the support by fitting, it can be fixed securely.

The heating roller according to any one of the first to ninth aspects may have a release layer on the outer surface of the heating roller as in the tenth aspect.

According to the eleventh aspect, the heating roller according to the first to tenth aspects can be used as a heat fixing device by being combined with a pressure roller.

[Brief description of the drawings]

FIG. 1 is a partially cutaway explanatory view for explaining a structure of a heating device according to an embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating a relationship between a mica sheet and a current-carrying heating element according to the first embodiment of the present invention. FIG. 2A is a plan view and FIG. 2B is a side view.

FIG. 3 is a perspective view of a cylindrical body in which the mica sheet of FIG. 2 is formed in an annular shape.

FIG. 4 is an explanatory view showing assembling of a heating roller according to the present invention.

FIG. 5 is a plan view illustrating a relationship between a mica sheet and an electric heating element according to the second embodiment.

FIG. 6 is a partially enlarged view of FIG. 5;

FIG. 7 is a perspective view of a cylindrical body in which the mica sheet of FIG. 5 is formed in an annular shape.

FIG. 8 is an enlarged cross-sectional view of a main part for describing a polymer body of the cylindrical body of FIG. 7;

FIG. 9 is a perspective view according to a first modification in which the mica sheet of FIG. 5 is formed in an annular shape.

FIG. 10 is a perspective view according to a second modification in which the mica sheet of FIG. 5 is formed in an annular shape.

11 is an enlarged cross-sectional view of a main part for describing a polymer body of the cylindrical body in FIG.

FIG. 12 is a plan view illustrating a relationship between a mica sheet and a current-carrying heating element according to a third embodiment.

FIG. 13 is a plan view illustrating a relationship between a mica sheet and a current-carrying heating element according to Modification Example 3.

FIG. 14 is a plan view illustrating a relationship between a mica sheet and a current-carrying heating element according to a comparative example.

FIG. 15 is a diagram showing a cross section for explaining the structure of a heating roll according to Embodiment 4 of the present invention, and FIG.
FIG. 15B is a side view, and FIG. 15B is an end view when cut at the center of FIG.

FIG. 16 is a plan view illustrating a sheet as a support shown in FIG.

FIG. 17 is a plan view illustrating a heating element as a heating layer shown in FIG.

18A and 18B are diagrams illustrating a relationship between a heating element and a sheet. FIG. 18A is a plan view as viewed from the front side, and FIG.
(B) is a plan view seen from the back surface (the side that becomes the center of the base).

FIG. 19 is an explanatory diagram illustrating assembly of the heating roller according to the present invention.

20 is a view for explaining a mandrel used in FIG. 19, FIG. 20 (a) is a plan view, and FIG. 20 (b)
Is a side view thereof.

FIG. 21 is an explanatory diagram illustrating assembly of a heating roller according to the present invention.

FIG. 22 is a schematic diagram illustrating a state of thermal expansion and contraction in the heating roller according to the present invention.

FIG. 23 is a plan view illustrating a modified example of the sheet as the support shown in FIG.

24 is a plan view illustrating a heating element as a heating layer used in combination with the sheet shown in FIG. 23.

FIG. 25 is a diagram illustrating a relationship between a heating element and a sheet, and is a plan view as viewed from a front surface side.

FIG. 26 is a side view illustrating a modification of FIG. 25.

FIG. 27 is a diagram illustrating a modification of the heating element of FIG. 24.

[Explanation of symbols]

 2: Heating roller 22: Base (core metal) 23: Insulating layer 24: Heat generating layer 30: Cylindrical body

Claims (11)

[Claims] 1. A heating roller in which a heat-generating layer that generates heat when energized is inscribed in a hollow cylindrical base via an insulating layer, wherein the insulating layer is formed by joining both sides of a rigid thin layer body. A heating roller using a cylindrical body fixed in a cylindrical shape. 2. The heating roller according to claim 1, wherein the joining portion is fixed by an engagement tongue formed to protrude from one side of the plate-shaped thin layer body. 3. The mating portion is formed by fitting an engaging tongue piece formed on one side of the plate-shaped thin layer body with an engaging hole formed on the other side opposite to the one side. The heating roller according to claim 1, wherein the heating roller is fixed. 4. The heating roller according to claim 2, wherein the engaging tongue piece is fixed by sandwiching a heating element forming the heating layer therebetween. 5. A heating roller in which a heating element which generates heat when energized is inscribed in a hollow cylindrical base via an insulating layer, wherein a support for supporting the heating element is provided at a center side of the heating element. A heating roller provided, wherein the heating element is supported by the support. 6. The heating roller according to claim 5, wherein the support has at least one notch, and a part of the heating element is supported by being locked by the notch. 7. The heating element according to claim 6, wherein the heating element is a sheet having an insertion portion into the cut, and the insertion portion is inserted into the cut and supported by the support. Heating roller. 8. The heating element according to claim 5, wherein the heating element has a folded portion that sandwiches the support by folding and that is supported by being sandwiched and supported by the support.
Heating roller according to item. 9. The support body has an engagement hole, the heating element has a locking portion fitted into the engagement hole, and the engagement hole and the locking portion are fitted. The heating roller according to claim 5, wherein the heating element is fixed to the support. 10. The heating roller according to claim 1, wherein the heating roller has a release layer on an outer surface.
Heating roller according to item. 11. A heating roller comprising: the heating roller according to claim 1; and a pressure roller rotatably pressed against the heating roller. A heat fixing device for nipping and fusing toner to printing paper.