JPH11194639A - Fixing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stick a resistance heating element consisting of stainless foil and constituting a heating layer in a hollow cylindrical roller core bar without causing lifting at the end. SOLUTION: Such control is performed that blast work is performed by a blast gun 21 while the resistance value of the resistance heating element 23 constituting the heating layer is measured by an ohmmeter and a blast controller 22, and the blast work is finished when the desired resistance value is attained. By performing the blast work, the worked surface of the heating element 23 is made rough, and adhesive force is improved by an anchor (anchoring) effect. One side or the end of the stainless foil forming the heating element 23 is blast-worked and warped toward the surface which is not blast- worked. By utilizing it, the heating element 23 is stuck in the hollow cylindrical roller core bar without causing the lifting at the end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing roller of a heat fixing device used for an apparatus utilizing an electrophotographic process such as a copying machine, a facsimile, a printer, and the like.

[0002]

2. Description of the Related Art As a method for fixing a toner image in an electrophotographic image forming apparatus or the like, a heat fixing method, a pressure fixing method, and a solvent fixing method 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 widely adopted. Among the heat fixing methods, the most common one is a method of heating from the inner surface of a metal roller with a halogen lamp.

[0003] However, this method has the drawbacks that the radiant heat is used, so that the energy conversion efficiency is poor, the power consumption is large, and the warm-up time is long. Therefore, as one of means for solving such a drawback, a direct heating method in which a metal core is provided with an insulating intermediate layer or an insulating core having a heating layer and a release layer is provided. Fusing rollers have been proposed.

The fixing roller of this type includes a type in which a heat generating layer is provided outside a metal core and a type in which a heat generating layer is provided inside a metal core. Since it is difficult to finish the shape of the heat generating layer such as straightness and undulation, it is difficult for the fixing roller of the type where the heat generating layer is provided outside the metal core to have the desired straightness and undulation on the roller surface after the release layer is provided. There is a disadvantage that it cannot be obtained.
On the other hand, the fixing roller of the type in which the heat generating layer is provided inside the metal core can have a release layer directly on the metal core, so that the surface shape does not matter, but it is difficult to form the heat generating layer inside. There is a problem.

FIG. 1 shows a configuration of a fixing roller of a type in which a heat generating layer is provided inside a metal core. The illustrated fixing roller 1 includes a release layer 11 for preventing paper and toner after fixing from adhering to the fixing roller, a roller core metal 12 serving as a base, an intermediate layer 13,
The heating layer 14 is formed. The intermediate layer 13 plays a role of insulating between the heat generating layer 14 and the roller core 12 and fixing the heat generating layer 14 to the roller core 12. In the figure, reference numeral 15 denotes an electrode.

[0006] The fixing roller 1 of the type in which the heat generating layer 14 is provided inside the roller core 12 is a roller core 12.
An intermediate layer 13 having an insulating property is formed on the inside, and a resin mandrel around which a resistance heating element serving as a heating layer 14 is wound is inserted inside the intermediate layer 13, and the roller mandrel 12 and the resin mandrel are heated. Pressure was applied from the difference in the coefficient of linear expansion of the resin to be formed, they were integrated, and the mandrel was removed when the temperature was lowered. That is, the mandrel and the roller core 1
The resistance heating element is formed by utilizing the pressure sandwiched in Step 2.

The resistance heating element includes a metal having a large volume resistance,
For example, foils such as stainless steel and nichrome are used. When such a metal is wound, it tends to expand due to its spring elasticity. Therefore, when the metal is wound on the inner surface of the roller core 12, the end does not follow the inner surface of the roller, and the intermediate layer 1 which is an insulating layer is formed.
It may cause floating from 3. In order to prevent floating, there is a method of providing a support layer inside the resistance heating element. However, there is a disadvantage that the heat capacity is increased and the warm-up is delayed.

[0008] The resistance heating element has a variation in resistance value. Causes include material composition, variations in foil thickness, and processing of foil shape (length, width). However, since the resistance value is directly related to power consumption, all of the above precisions have been improved. There must be. For example, when the standard value of the power consumption is 100 V and 800 W ± 50 W, the variation of the resistance value must be controlled at 12.5Ω ± 0.83Ω.

A fixing roller of the type in which the above-mentioned heat generating layer is provided inside the core metal is disclosed in Japanese Patent Application Laid-Open No. 58-19 / 1983.
Japanese Patent Application Laid-Open No. H8-305197, in which a surface heating element and a heat insulating material are successively attached in a layered manner on the inner surface of a fixing roller, as in the fixing device of an electrophotographic copying machine disclosed in Japanese Patent Application Laid-Open No. 6-305197.
As in the fixing heating roller disclosed in Japanese Patent Application Laid-Open Publication No. H11-163, a resistance heating element is adhered and fixed to the inner peripheral surface of the fixing roller, a resistance heating member is formed on one surface of the insulating film material, and a heat conductor is applied to the other. Fixed to the roller inner peripheral surface with the resistance heating element facing the center of the roller, and further provided with a resistance heating layer via an insulation layer inside the hollow cylindrical base, together with the insulation layer There is also a type in which a support layer sandwiching the heat generating layer is provided inside the roller to prevent floating.

[0010]

According to the first aspect of the present invention, there is provided a fixing roller comprising at least a hollow cylindrical base, a release layer, An electrophotographic apparatus comprising: a heating layer that generates heat by applying a voltage; and an insulating layer that electrically insulates the base and the heating layer from each other, wherein the heating layer is formed on the center side of the base. Wherein the resistance heating element forming the heating layer is blasted.

According to a second aspect of the present invention, the resistance heating element is formed by blasting an end on one side.

According to a third aspect of the present invention, the resistance heating element is formed by blasting the entire surface on one side and the center portion of the surface on the other side.

According to a fourth aspect of the present invention, the resistance heating element is formed by performing blast processing while measuring resistance.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In the following, description will be made by assigning common reference numerals to parts common to the related art. FIG. 2 is a conceptual diagram for explaining a resistance control method when manufacturing the fixing roller according to one embodiment of the present invention. In the figure, reference numeral 21 denotes a blast gun, 22 denotes a resistance meter and a blast control device, and the resistance value of a resistance heating element 23 which is a material forming the heating layer 14 is measured by the resistance meter and the blast control device 22 by the blast gun 21. The blast processing is performed, and control is performed to end the blast processing when the resistance value reaches a desired value. In this way, the resistance of the resistance heating element 23 can be controlled.

When the blasting is performed, the processed surface of the resistance heating element 23 becomes rough, and the adhesive force is improved by an anchor (anchoring) effect. However, the resistance increases because the effective cross-sectional area through which electricity flows decreases. . Since the resistance change changes throughout the resistance heating element, the heat generation distribution does not change. When one surface of the stainless steel foil is blasted, the surface is warped toward the surface that has not been blasted.

[0016]

Embodiments of the present invention and comparative examples will be described below with reference to the drawings. <Example 1> A fixing roller as shown in FIG. 1 was manufactured, and the roller core 12 had a diameter of 30 mm × 370 mm and a thickness of 0.4 mm.
mm of aluminum was used. Stainless steel foil (SUS304) was used as the resistance heating element 23, and mica was used as a material constituting the intermediate layer 13 for insulation. The stainless steel foil was blasted on both sides while measuring the resistance as shown in FIG. The resistance value before blasting is 12.
It was 2Ω, but it became 12.5Ω after blasting. The stainless steel foil and mica were adhered to the inner surface of the roller core 12 to form the heat generating layer 14 and the intermediate layer 13, and a perfluoroalkoxy resin (PFA resin) was formed as the outermost layer to form the release layer 11.

<Embodiment 2> FIG. 3 is a plan view (A) and a cross-sectional view (B) showing the pattern of the resistance heating element 23. A mask was applied to one side of the end (the end when wrapped around the circumference) of the stainless steel foil having a pattern as shown in FIG. 3 so as not to be blasted, and the remaining part was blasted. All other surfaces were blasted. FIG. 4 is a sectional view showing the blast processing. In FIG. 4, the part shown by a thick line shows a blast surface. Then, the end of the stainless steel foil constituting the resistance heating element 23 became a curved surface as shown in FIGS. Then, the entire surface was blasted and attached to the inner surface of the roller core 12 via mica. The heat-generating layer 14 thus formed has an overall improved adhesive strength due to the anchor effect, and is adhered along the curved surface of the roller, so that the end does not float and is properly adhered as shown in FIG. Was. FIG. 7 shows a state where the end of the heat generating layer 14 is floating.

<Embodiment 3> As in Embodiment 2, only the end (the end when wrapped around the circumference) of one surface of the resistance heating element 23 made of a stainless steel foil having a pattern as shown in FIG. 3 is blasted. processed. FIG. 8 is a sectional view showing the blast processing. Both ends of the resistance heating element 23 were curved as shown in FIGS. Then, the blasted surface was affixed to the inner surface of the roller core 12 via mica with the surface facing out. Also in this example, the heat generating layer 14 has an overall improved adhesive force due to the anchor effect, and also adheres along the curved surface of the roller, so that the end does not float and is properly adhered as shown in FIG. .

<Comparative Example> The resistance heating element 23 of the pattern of Example 2 was adhered to the inner surface of the roller core 12 via mica without performing blasting. In this case, the heating layer 14
In FIG. 7, due to the spring elasticity of stainless steel, the end portion was lifted as shown in FIG.

[0020]

As described above, the fixing roller according to the first aspect performs blast processing on the resistance heating element constituting the heating layer, so that the fixing roller is securely adhered to the inside of the hollow cylindrical base. There is an effect that can be.

In the fixing roller according to the second aspect, since only one end of the end of the resistance heating element is blasted, the end of the resistance heating element has a curved surface and is securely adhered to the inside of the hollow cylindrical base. There is an effect that can be.

In the fixing roller according to the third aspect, the resistance heating element has one surface entirely blasted, and this surface is adhered to the insulating layer. Since the center portion of the surface is blasted and the end portion is not blasted, the end portion has a curved surface, and there is an effect that the surface can be securely adhered to the inside of the hollow cylindrical base.

The fixing roller according to the fourth aspect performs the blast processing while measuring the resistance of the resistance heating element. Therefore, in addition to the above-described common effect, the resistance heating element can obtain a desired resistance, and the desired consumption can be achieved. There is an effect that a fixing roller having electric power can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a fixing roller of a type in which a heat generating layer is provided inside a metal core.

FIG. 2 is a conceptual diagram for describing a resistance control method when manufacturing a fixing roller according to an embodiment of the present invention.

FIG. 3 is a plan view (A) and a cross-sectional view (B) showing a pattern of a resistance heating element constituting a heating layer.

FIG. 4 is a cross-sectional view illustrating an example of blast processing of a resistance heating element.

FIGS. 5A and 5B are a plan view and a cross-sectional view, respectively, showing a pattern of a resistance heating element whose end portion has a curved surface by blasting.

FIG. 6 is a cross-sectional view showing a state in which a resistance heating element having a curved end is attached to an inner surface of a roller core.

FIG. 7 is a cross-sectional view showing a state where a resistance heating element whose end is not curved is attached to an inner surface of a roller core.

FIG. 8 is a cross-sectional view showing another example of the blast processing of the resistance heating element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing roller 11 Release layer 12 Roller core 13 Insulation layer 14 Heat generation layer 15 Electrode 21 Blast gun 22 Resistance meter and blast control device 23 Resistance heating element

Claims (4)

[Claims] 1. A semiconductor device comprising at least a hollow cylindrical base, a release layer, a heat generating layer that generates heat by applying a predetermined voltage, and an insulating layer that electrically insulates the base from the heat generating layer. A fixing roller for an electrophotographic apparatus, wherein the heating layer is formed on the center side of the substrate, wherein the resistance heating element forming the heating layer is blasted. 2. The fixing roller according to claim 1, wherein the resistance heating element is formed by blasting an end on one side. 3. The fixing roller according to claim 1, wherein the resistance heating element is formed by blasting the entire surface on one side and the center of the surface on the other side. 4. The fixing roller according to claim 1, wherein the resistance heating element is formed by performing blast processing while measuring resistance.