JP2012252190A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device capable of controlling a heat generating part according to heated objects having various width and thickness.SOLUTION: There is provided a fixing device comprising a control device for supplying power to a required circuit and a heat generation body for generating heat by power supplied by the control device, in which the heat generation body is composed of a plurality of independent heat generating parts containing at least polyimide and controls the range for generating heat according to the size of heated object by supplying power to an electrode of the heat generating parts individually provided by the control device according to the size of heated object.

Description

  In the present invention, the heating element is composed of a plurality of independent heating parts each including at least polyimide, and each heating part has power supplied to the electrodes of the heating part individually provided by the control device according to the size of the heated object. The present invention relates to a fixing device. More specifically, the present invention relates to a fixing device that can suppress an electric supply to an unnecessary portion of the heating element by controlling a heating part that generates heat according to the size of the heated object.

  In an electrophotographic image forming apparatus such as a copying machine, a laser beam printer, a facsimile, or a complex machine called MFP having these functions, an electrostatic latent image of an image formed on a photosensitive member is developed with toner. After this is transferred to a recording medium, the image is fixed by fixing the image using a fixing device, and the image is recorded.

  As a fixing device used in such an image forming apparatus, conventionally, a heat roller type fixing device using a metal roller having a halogen lamp disposed on the inner surface as a heat source has been used.

  In Patent Document 1, since the halogen lamp converts electrical energy into light energy and then converts it into heat energy, the heat conversion efficiency is low, so the electrical energy is directly converted into heat energy on the outer periphery of the core of the heat roller. Techniques for forming possible resistance heating elements have been proposed.

  Further, Patent Document 2 proposes a fixing device using a semi-cylindrical heat plate in which a sheet heater is arranged on the inner surface of a non-rotating semi-cylindrical body. This is a fixing belt type fixing device configured to wrap and heat a fixing belt around the outer peripheral surface of a semi-cylindrical heat plate, and the heat capacity of the heat plate can be reduced, so that energy can be saved. However, since the fixing belt is wound between the heat plate and the fixing roller and tension is applied to the fixing belt, the frictional force between the heat plate and the fixing belt is increased, and the slidability of the fixing belt is poor. There is an inconvenience of becoming.

  Further, Patent Document 3 discloses a heater that can generate only a part of heat by providing a branch electrode on the heater heating element. This heater can generate heat when it passes through a wide heated object, and only a part of the heater can generate heat when it passes through a narrow heated object. Overheating of the part can be prevented, printing can be performed without reducing productivity, and arbitrary power can be supplied to each part, making it possible to cope with differences in the thickness of the transfer material. is there. However, in the disclosed heater, the area of the heater has to be increased in order to increase the number of branches in order to deal with heated objects of various widths, that is, the fixing device is increased in size and the heat capacity associated therewith. This increases the time required to heat the fixing device to a printable temperature after the power is turned on. Therefore, it is necessary to preheat the heater in advance in order to always be in a printable state, which consumes a lot of power and is not preferable from the viewpoint of energy saving. Therefore, it is difficult to divide many, and it is considered that it is actually difficult to cope with three or more types of heated objects.

  Further, Patent Document 4 discloses a heater using a heating resistor having a characteristic that the resistance value increases as the temperature rises. In this heater, the current is reduced and the calorific value is reduced due to the resistance increase accompanying the temperature rise, so that it is possible to prevent overheating of the heated portion non-passing portion. However, it is possible to deal with heated objects of various widths, but on the other hand, the heater itself has a temperature control mechanism that works at a specific temperature, and temperature control corresponding to the thickness of the heated object is impossible There is. Furthermore, even in a portion where the heated body does not pass, heat is generated up to the temperature at which the temperature control mechanism operates, so that the portion where the heated body does not pass is also heated, which consumes unnecessary power and is not preferable from the viewpoint of energy saving.

  Further, Patent Document 5 discloses a heater in which a temperature switch is provided for each of resistance wires arranged in parallel. In this heater, the temperature switch is turned off due to the temperature rise and the current is cut off, so that overheating of the heater can be prevented. However, similarly to Patent Document 4, the temperature control mechanism is operated even in a portion where the heated object does not pass. Generates heat, which also warms the part through which the object to be heated does not pass, which consumes unnecessary power and is not preferable from the viewpoint of energy saving.

  Further, Patent Document 6 discloses a fixing device in which electricity is supplied to a necessary portion by providing a power supply switch for directly controlling power supply to a heating element. By using this fixing device, electricity can be supplied to necessary parts and the heating element can be heated. However, in order to control by providing a plurality of heating parts, there is a problem that the heating element itself must be enlarged. It was.

Japanese Patent Laid-Open No. 07-140828 JP 2001-343849 A Japanese Patent Laid-Open No. 3-194879 JP 2000-58232 A JP 2009-245729 A JP-A-6-332338

  The present invention has been made in view of the above-described background, and an object of the present invention is to provide a fixing device capable of controlling a heat generating portion according to a heated object having various widths and thicknesses. There is.

  A fixing device according to a first aspect of the present invention is a fixing device including a control device that supplies electric power to a necessary circuit and a heating element that generates heat by the electric power supplied from the control device, wherein the heating element It consists of a plurality of independent heat generating parts including at least polyimide, and electric power is supplied to the electrodes of the heat generating parts individually provided from the control device in accordance with the size of the object to be heated. A control device for supplying electric power and a heating element used in the fixing device of the present invention are provided as shown in FIG. Hereinafter, a control device for supplying electric power provided in the fixing device of the present invention and a heating element including a plurality of independent heating units will be described in detail.

(1) Control device for supplying electric power The control device for supplying electric power used in the present invention supplies electric power to a necessary circuit according to the size of an object to be heated. Information relating to the size of the object to be heated may be manually input information relating to the size of the object to be heated, or may be read by a detection device or the like.

(2) Heating element comprising a plurality of independent heat generating parts The heat generating element used in the present invention comprises a plurality of independent heat generating parts, and the heat generating part includes at least polyimide. Since the heat generating portion contains polyimide, it has excellent heat resistance and flexibility, so that it can be used in a shape where the heat generating element is curved.

  Moreover, it is preferable that the heat generating portion described above has a square shape. It is preferable that the heat generating portion has a square shape. The square shape makes it easy to uniformly control the heat generation of the heat generating portion.

  Moreover, it is preferable that the heat generating portions of the heat generating elements are arranged so that the center of gravity of the heat generating portions is linear. By arranging the center of gravity of the heat generating part to be linear, the object to be heated can be efficiently heated. However, the center of gravity of the heat generating part may not be arranged in a straight line according to the shape of the object to be heated. For example, the center of gravity of the heat generating part may be arranged in a zigzag shape.

  Furthermore, the heat generating part may rotate in the circumferential direction by substantially equal angles around the center of gravity of the heat generating part. By rotating the center of gravity of the heat generating portion by an equal angle around the axis, the temperature variation of the fixing belt due to the gap between the heat generating portions can be suppressed.

  When the heat generating part is rotated about the center of gravity of the heat generating part, it is preferable that the heat generating parts have the same shape. If the shape of the heat generating part is the same, the heat generating part can be provided evenly, so that the heat generating element can generate heat more uniformly. In the case where the heat generating portions are evenly provided, the heat generating portions are preferably arranged so as to satisfy d ≦ sin θ (l cos θ−w sin θ), 0 ° <θ <90 °, and d> 0. D is the distance between adjacent heat generating parts, θ is the angle of rotation about the center of gravity of the heat generating part, l is the length of the side facing one direction of the square, and w is the length of the remaining facing side of the square. It is preferable that the heat generating portion does not contact the adjacent heat generating portion.

  A fixing device according to a second aspect of the present invention is characterized in that an insulating layer is provided on at least one surface of the heat generating portion described above.

  The fixing device according to a third aspect of the present invention is characterized in that a heat transfer member is provided on at least one surface of the insulating layer described above. Since the heat conductivity is good by providing the heat transfer member on at least one surface of the insulating layer, the temperature of the entire heating element can be made uniform. Examples of the heat transfer member include metal materials such as stainless steel, aluminum, nickel, and copper, ceramic materials such as alumina, aluminum nitride, boron nitride, and silicon nitride, and graphite. Is preferred.

  The fixing device according to the fourth curved surface of the present invention is characterized in that the heat generating portion is formed by screen printing or a metal mask. Therefore, when forming a heat generating part, the polyimide which forms at least a heat generating part is apply | coated by the paste form as a polyamic acid (precursor solution). The method of forming the heat generating portion is not limited to screen printing or a metal mask, and it is sufficient if the heat generating portion can be formed using a paste-like polyamic acid. The heat generating part is formed by baking the applied paste-like polyamic acid. However, it is not necessary to bake according to conditions, such as a solvent to be used and an imidizing agent.

  By using the fixing device of the present invention, it is possible to control the heat generating portion that generates heat according to the size of the object to be heated, and to suppress the supply of electricity to the unnecessary portion of the heat generated.

1 is a cross-sectional view illustrating a configuration of a fixing device according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a fixing device according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a fixing device according to an embodiment of the present invention. It is a top view of the heat generating body in connection with implementation of this invention. It is a top view of the heat generating body in connection with implementation of this invention. It is a top view of the heat generating body in connection with implementation of this invention. It is a top view of the heat generating body in connection with implementation of this invention. It is a top view of the heat generating body in connection with implementation of this invention. FIG. 3 is a conceptual diagram of a fixing device control method according to an embodiment of the present invention.

  The fixing device according to the present invention will be described below. More specifically, a heating element that has only a plurality of independent heating portions and can heat only the necessary heating portion and a fixing device including the heating member will be described with reference to the drawings. The form is not limited at all.

(1) Description of Fixing Device FIGS. 1 to 3 show an example of a schematic configuration diagram of a fixing device according to the present invention. The fixing device shown in FIG. 1 includes a pressure roller 1, a fixing film 2 and a heating element 4, and preferably has a heat transfer member 3 between the heating element and the fixing film 2. The heat generating member 4 and the heat transfer member 3 are laminated, and the heat transfer member 3 is disposed in contact with the inner surface of the fixing film 2 and in pressure contact with the pressure roller 1. The pressure roller 1 is driven to rotate by a driving means (not shown), and the fixing film 2 rotates while sliding against the heat transfer member 3 that is fixed. The pressure roller 1 has, for example, a three-layer structure in which a metal core, an elastic layer, and a release layer are formed in this order from the inside. For the metal core, for example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof is used. In addition, a heat-resistant rubber material such as silicon rubber or fluorine rubber is suitable for the elastic layer, and a fluorine-based material such as PFA, PTFE, or ETFE is suitable for the release layer. The fixing film 2 is made of PFA, PTFE, ETFE having excellent heat resistance and releasability as a release layer on the surface of a seamless cylindrical substrate made of a heat resistant resin such as polyimide or a metal material such as stainless steel or nickel. It has a structure in which a fluororesin such as is formed. Further, a heat-resistant rubber material such as silicon rubber or fluororubber may be formed as an elastic layer between the base material and the release layer. Moreover, you may form fluorine resin layers, such as PFA, PTFE, and ETFE, on the inner surface of a base material. Thereby, a sliding load with the heat transfer member 3 can be reduced.

  When printing is started, the width information of the heated body output from the heated body width information output device 16 is input to the power supply device 14, and the width information of the heated body is processed in the power supply device 14. The power is supplied to a predetermined part of the plurality of independent heating units 10 through the power supply line 15 based on the heating unit 10 and the heating unit 10 generates heat, and the unfixed toner 6 on the heated body 5 is passed through the heat transfer member 3 and the fixing film 2. It is melted and fixed to the heated object to fix the image.

  Next, the fixing device shown in FIG. 2 includes a pressure roller 1, a fixing belt 8, a fixing roller 7, and a heating element 4, and preferably has a heat transfer member 3 between the heating element and the fixing belt 8. The fixing belt 8 is stretched between the heating element 4 laminated with the fixing roller 7 and the heat transfer member 3, and the pressure roller 1 is pressed against the fixing roller 7 via the fixing belt 8. Are arranged. The pressure roller 1 and the fixing roller 7 are rotationally driven by a driving unit (not shown) to drive the fixing belt 8. The heat generated from the heating element 4 is transmitted to the fixing belt 8 through the heat transfer member 3, and the fixing belt 8 conveys heat to the fixing portion between the fixing roller and the pressure roller by rotation, and is undetermined on the heated body 5. The toner 6 is melted and fixed to the heated body to fix the image. The fixing roller 7 has, for example, a two-layer structure in which a core metal and an elastic layer are formed in order from the inside. For the metal core, for example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof is used. For the elastic layer, a heat-resistant rubber material such as silicon rubber or fluorine rubber is suitable. The fixing belt 8 is formed of a heat-resistant rubber material such as silicon rubber or fluororubber as an elastic layer on the surface of a seamless cylindrical substrate made of a heat-resistant resin such as polyimide or a metal material such as stainless steel or nickel. In addition, the release layer has a structure in which a fluororesin such as PFA, PTFE, or ETFE having excellent heat resistance and releasability is formed. Moreover, you may form fluorine resin layers, such as PFA, PTFE, and ETFE, on the inner surface of a base material. Thereby, a sliding load with the heat transfer member 3 can be reduced.

  Next, the fixing device shown in FIG. 3 includes a pressure roller 1, a fixing roller 9, and a heating element 4, and preferably has a heat transfer member 3 between the heating element and the fixing roller 9. The heat generating member 4 and the heat transfer member 3 are laminated so that the heat transfer member 3 is in pressure contact with the surface of the fixing roller 9 and the pressure roller 1 is in pressure contact with the fixing roller 9. The pressure roller 1 and the fixing roller 9 are rotationally driven by driving means (not shown). Between the heat generating body 4 and the heat transfer member 3 and the fixing roller 9, a seamless belt that freely rotates in a form including the heat generating body 4 and the heat transfer member 3 may be interposed. As a result, wear on the surface of the fixing roller can be reduced. The fixing roller 9 has, for example, a three-layer structure in which a core metal, an elastic layer, and a release layer are formed in order from the inside. For the metal core, for example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof is used. In addition, a heat-resistant rubber material such as silicon rubber or fluorine rubber is suitable for the elastic layer, and a fluorine-based material such as PFA, PTFE, or ETFE is suitable for the release layer.

(2) Heating element FIGS. 4 to 8 show an example of a configuration diagram of a heating element according to the present invention. The plurality of independent heating elements 10 of the heating element according to the present invention are such that at least the plurality of heating elements 10 are electrically independent, and the power supply electrode 11 is provided so that power can be individually applied to control the heating. It is arranged. Further, the insulating layer 12 may be provided on at least one surface of the heat generating portion, and a heat transfer member may be provided on at least one surface of the insulating layer 12. Furthermore, the surface may be coated with a fluorine-based material such as PFA, PTFE, or ETFE in order to reduce sliding resistance with a fixing film, a fixing belt, a fixing roller, or the like, or for wear resistance.

  The thickness of the heating element 4 is preferably 0.01 mm or more and 1 mm or less, and more preferably 0.05 mm or more and 0.5 mm or less. If it is thinner than this, the strength of the heating element cannot be secured, and there is a risk of damage in the fixing device. If it is thicker than this, the heat capacity of the heater itself becomes too large, and it takes time for the temperature to rise after power is turned on.

  Next, the shape and arrangement of the heating part 10 of the heating element will be described with reference to FIGS. The shape of each heat generating part 10 is preferably rectangular, and examples thereof include a rectangle, square, rhombus, parallelogram, trapezoid, and the like. In particular, when the shape is rectangular or square, the current flow inside the heat generating part is uniform and uniform. It is more preferable because an exothermic distribution can be obtained. Further, although the arrangement of the plurality of heat generating units 10 is not particularly limited, the heat generating units are arranged over substantially the entire passage width of the object to be heated. It is preferable that the centers of gravity of the heat generating portions are arranged in a straight line because the heat generating portions can be arranged efficiently and the area of the heat generating body can be reduced. Moreover, if the shape of the several independent heat generating part is the same shape, since a heat generating part can be provided equally, a heat generating body can be heated more uniformly.

  7 and 8 show a configuration other than the heat generating unit 10 shown in FIGS. 7 and FIG. 8, when the heat generating part 10 is provided equally, the heat generating part 10 satisfies d ≦ sin θ (l cos θ−w sin θ), 0 ° <θ <90 °, d> 0. It is preferable that they are arranged. D is the distance between adjacent heat generating portions 10, θ is the angle of rotation about the center of gravity of the heat generating portion 10, l is the length of a side facing one direction of the square, and w is the length of the remaining facing sides of the square. It indicates the length, and it is preferable that the heat generating part 10 does not contact the adjacent heat generating part 10. When arranged in this way, the adjacent heat generating portions overlap with the passing direction of the heated member 5 passing therethrough, so that uniform fixing is possible.

  In the heat generating part, it is particularly preferable that 10 includes at least polyimide and further includes a conductive material, and may further include an insulating material. The heat generating part 10 is a solution made of polyimide or a precursor thereof. In addition, the paste-like composition containing the conductive material is printed on the pattern of the independent heating portion 10 by screen printing, a metal mask, or other printing means, and then formed by means such as drying, baking, and curing. The Here, the polyimide is obtained by reacting an aromatic diamine component and an aromatic tetracarboxylic acid component and imidizing thermally or chemically.

  Examples of the aromatic diamine component of polyimide used in the heat generating portion of the present invention include 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenyl ether, 1,4-diaminobenzene, , 3-diaminobenzene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,4-diaminotoluene, 3,4′-biphenyldiamine, 3,4′-diaminodiphenyl sulfoxide, 2,2-bis (3-aminophenyl) propane, 4,4′-diaminobenzophenone, 3,3′-biphenyldiamine, 3,4′-diaminodiphenyl ether, 2,6-diaminotoluene, 4,4′-biphenyldiamine, 3,3 '-Diaminodiphenylsulfone, 3,4'-diaminodiphenylmethane, 3,3'- Aminodiphenyl ether, 4,4′-bis (4-aminophenyl) sulfide, 3,3′-diaminodiphenylmethane, 2,2-bis (4-aminophenyl) propane, 2,2- (3-aminophenyl) (4 -Aminophenyl) propane, 3,3'-diaminobenzophenone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-bis (4-aminophenyl) sulfide, 4,4'-diaminodiphenyl Sulfoxide, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfone, 2,5-diaminotoluene, 3,3'-diaminodiphenyl ether, 4,4'-bis ( 4-aminophenyl) sulfide, 3,3′-diaminodiphenylmethane, 2,2-bis ( 4-aminophenyl) propane, 2,2- (3-aminophenyl) (4-aminophenyl) propane, 3,3′-diaminobenzophenone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 2, 2′-dimethyl-4,4′-diaminobiphenyl, 3,4′-bis (4-aminophenyl) sulfide, 3,3′-bis (4-aminophenyl) sulfide, 4,4′-diaminodiphenylsulfoxide, 3,4′-diaminobenzophenone, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfone, 2,5-diaminotoluene, 3,3′-hydroxy-4,4′-diaminobiphenyl, 1, 3-bis- (3-aminophenoxy) benzene, 1,3-bis- (4-aminophenoxy) benzene, 1,4-bis- 4-aminophenoxy) benzene, 4,4′-bis- (4-aminophenoxy) biphenyl, 4,4′-bis- (3-aminophenoxy) biphenyl, diaminobenzoanilide, methylenedianiline, 2,2 ′, -Bis (trifluoromethyl) -4,4 ', 3,7-diamino-dimethyldibenzothiophene-5,5-dioxide, 9,9-bis (4-aminophenyl) fluorene, which may be used alone or It is preferable to use 4,4′-diaminodiphenyl ether or 1,4-diaminobenzene because the heat resistance of the heat generating part 10 can be increased.

  The aromatic tetracarboxylic acid component of the present invention includes 3,4,3 ′, 4′-benzophenonetetracarboxylic acid, pyromellitic acid, 3,4,3 ′, 4′-biphenyltetracarboxylic acid, 3,4 , 3 ′, 4′-diphenyl sulfoxide tetracarboxylic acid, 2,3,3 ′, 4′-diphenyl ether tetracarboxylic acid, 3,4,3 ′, 4′-diphenyl sulfide tetracarboxylic acid, 2,3,3 ′ , 4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-diphenylmethanetetracarboxylic acid, 3,4,3 ′, 4′-diphenyl (2,2-isopropylidene) tetracarboxylic acid, 2,3 , 3 ′, 4′-diphenylsulfoxide tetracarboxylic acid, 3,4,3 ′, 4′-diphenyl ether tetracarboxylic acid, 3,4,3 ′, 4′-diphenylsulfo Tetracarboxylic acid, 2,3,3 ′, 4′-diphenylsulfonetracarboxylic acid, 2,3,3 ′, 4′-diphenylsulfidetetracarboxylic acid, 3,4,3 ′, 4′-diphenylsulfane Tetracarboxylic acid, 2,3,3 ′, 4′-benzophenonetetracarboxylic acid, 2,3,3 ′, 4′-diphenyl (2,2-isopropylidene) tetracarboxylic acid, 4,4 ′-(hexafluoro) Isopropyl) phthalic acid, bisphenolic acid and its ester compounds, anhydrides, and the like. These may be used alone or in combination, such as 3,4,3 ′, 4′-biphenyltetracarboxylic acid, pyromellitic acid. Is preferable because the heat resistance of the heat generating portion 10 can be increased.

  Polar organic solvents useful in the present invention include, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazo Lidinone, N-methylcaprolactam, hexamethylphosphoric triamide, 1,2-dimethoxyethane, diglyme, triglyme, tetrahydrofuran, 1,4-dioxane, γ-butyrolactone, dimethyl carbonate, diethyl carbonate, ethylene carbonate , Propylene carbonate, diethoxyethane, dimethyl sulfoxide, sulfolane, methanol, ethanol, isopropyl alcohol, ethylene glycol, propylene glycol, ethyl cellosolve, butyl cellosolve and the like. Preferred solvents are N-methyl-2-pyrrolidone and N, N-dimethylformamide. These solvents can be used alone or as a mixture or mixed with other solvents such as toluene, xylene, that is, aromatic hydrocarbons.

  Here, the solution composed of the polyimide precursor is not particularly limited as long as it can be imidized thermally or chemically to form a polyimide, but preferably the dianhydride of the above aromatic diamine component and aromatic tetracarboxylic acid component. The product is dissolved in the above polar organic solvent and reacted to form a solution of polyamic acid which is a polyimide precursor. Or the ester compound of the said aromatic diamine component and aromatic tetracarboxylic acid component is dissolved in the said polar organic solvent, and it is set as a polyimide precursor solution.

  The conductive material of the present invention preferably contains a conductive filler having conductivity, and the conductive filler having conductivity is not particularly limited, but has a size of 0.01 to 100 μm, a spherical shape, a lump shape, and the like. Scale, fiber, whisker, strand, coil, dendritic, nickel, copper, gold, silver, platinum, palladium, tungsten, molybdenum, zinc, aluminum, chromium, cobalt, zirconium, Metals such as tin, titanium, iron, niobium, vanadium, etc., or alloys such as stainless steel, nichrome, solder, brass, bronze, tungsten carbide, tantalum carbide, tungsten disilicide, tungsten boride, molybdenum boride, molybdenum carbide, two Molybdenum silicide, titanium carbide, titanium diboride, titanium disilicide, titanium nitride, carbide , Chromium diboride, chromium disilicide, zirconium carbide, zirconium diboride, zirconium disilicide, zirconium nitride, vanadium carbide, niobium carbide, niobium diboride, niobium disilide, tantalum diboride, two Metal compounds such as tantalum silicide and tantalum nitride, graphite, expanded graphite, carbon black, carbon fiber, vapor grown carbon fiber, carbon nanotube, carbon microcoil, graphene and other carbon compositions, or glass, graphite, ceramic, etc. And at least one filler selected from the group consisting of a conductive material obtained by coating the core particles with a conductive material.

  In addition, the heat generating portion 10 including at least polyimide may further include an insulating member. As the insulating material of the present invention, an insulating filler may be added for the purpose of improving the strength, improving the thermal conductivity, improving the fluidity of the paste, etc., and is not particularly limited, but preferably has a size of 0.01 μm to 100 μm, Spherical, earthy, scaly, fibrous, strand, and dendritic shapes include glass fiber, boron nitride, alumina, titanium oxide, talc, sepiolite, and the like.

  In addition, an insulating layer 12 is preferably disposed on at least one surface of the heat generating portion 10 of the heat generating element, which is essential when the heat transfer member 3 is not used or when the heat transfer member 3 is conductive. is there. Although it does not specifically limit as the insulating layer 12, it is preferable that it is heat resistant and flexible, and it is especially preferable that it is a polyimide membrane | film | coat or film. More preferably, the other surface of the heat generating portion is also provided with an insulating layer 13.

  Furthermore, the heat transfer member 3 may be provided on at least one surface of the insulating layer 12. The heat transfer member 3 efficiently transfers the heat from the heating element 4 to the fixing film 2, the fixing belt 8, the fixing roller 9, and the like, and further suppresses a rapid temperature change of the heating element 4 to facilitate temperature control. Examples of the material include metal materials such as stainless steel, aluminum, nickel, and copper having high thermal conductivity, ceramic materials such as alumina, aluminum nitride, boron nitride, and silicon nitride, and graphite, and the thickness ranges from 0.1 mm to 5 mm. In view of strength and heat capacity, a range of 0.2 to 2 mm is more preferable. Further, the heat transfer member protects the heating element from sliding wear with the fixing film 2, the fixing belt 8, the fixing roller 9, and the like. Moreover, when the heat transfer member 3 is a conductive member and is connected to a leakage breaker, the leakage current can be quickly detected and the power supply can be cut off when the heating element breaks, so that safety can be improved. Can do. In order to reduce the sliding resistance on the sliding surface with the fixing film 2, the fixing belt 8, the fixing roller 9, etc., coating with a fluorine-based material such as PFA, PTFE, ETFE or the like may be performed.

  In addition, a power supply electrode 11 to which electricity is supplied is provided in the heat generating portion, and the power supply electrode 11 is not particularly limited as long as it has higher conductivity than the heat generating portion 10. As a preferred form, a solution comprising a polyimide or a precursor thereof and a paste-like composition containing a conductive material, or an organic solvent with metal nanoparticles, particularly preferably silver nanoparticles, gold nanoparticles, palladium nanoparticles, platinum The conductive ink in which the nanoparticles are dispersed is printed on the pattern of the feeding electrode by screen printing, a metal mask, or other printing means, and then formed by means such as drying, baking, and curing. Alternatively, the power supply electrode 11 may be formed by forming a metal film of nickel, copper, gold, silver, or the like by plating, sputtering, vapor deposition, adhesion of a metal foil, or the like.

(3) Power Control Device Next, the power control device for the fixing device of the present invention shown in FIG. 9 will be described. Heated body width information output device 16 that acquires and inputs size information of heated body 5 and heat generation at a position corresponding to a portion through which heated body 5 passes based on the size information of heated body 5 A power supply device 14 that can selectively supply power to the unit, and a heating element 4 that includes a plurality of heat generating units 10 independent of a power supply line 15 that sends power from the power supply device 14. The power supply line 15 is connected to the power supply electrode 11 connected to a plurality of independent heat generating parts 10 by crimping or soldering. Further, although not shown, it is more preferable that a temperature sensor is installed on the surface of the heating element and / or the fixing film 2, the fixing belt 8, the fixing roller 9 and the like, and temperature information from the temperature sensor is input to the power supply device 14.

  The heated body width information output device 16 acquires the heated body size information at the time when the heated member is supplied and printing is started, and the obtained heated body size information is sent to the power supply device 14. Output. The method for obtaining the size information of the heated object is not particularly limited, but is detected by a sensor arranged in the heated object introducing unit, or the user inputs the size information of the heated object, or A method for obtaining the size information of the object to be heated by a combination of these can be mentioned.

  The power supply device 14 receives the size information of the heated body 5 from the heated body width information output device 16, processes this information, and fixes the fixing film 2 and the fixing belt when the heated body 5 passes. 8. Power is supplied to each independent heating unit 10 of the heating element 4 through the power supply line 15 and the feeding electrode 11 so that the temperature of the passage width of the heated body 5 such as the fixing roller 9 becomes a temperature suitable for fixing. To do. Alternatively, it is possible to shorten the warm-up time by supplying power to all the heat generating units 10 in advance and preheating the fixing device to a temperature at which fixing can be started quickly. Subsequently, when the passage of the heated body 5 continues, the heated body 5 of the plurality of independent heating units 10 is supplied so as to supply the amount of heat that supplements the amount of heat that the heated body 5 brings out. Additional electric power is supplied to the heat generating part 10 of the passing part. At this time, temperature information from the temperature sensor is input to the power supply device 14 and the power supply is controlled based on the temperature information so that the temperature is appropriate for fixing, thereby enabling more accurate control.

  Hereinafter, the present invention will be described in more detail with reference to examples.

<Fixing device>
As the fixing device, the fixing device shown in FIG. 2 was used. The fixing device includes a pressure roller 1, a fixing belt 8, a fixing roller 7 and a heating element 4, and has a heat transfer member 3 between the heating element and the fixing belt 8. The fixing belt 8 is stretched between the heating element 4 laminated with the fixing roller 7 and the heat transfer member 3, and the pressure roller 1 is pressed against the fixing roller 7 via the fixing belt 8. Are arranged.

<Creation of heating element>
The top view of the heat generating body 4 used for FIG. 4 was shown. The heating element 4 has a total length of 360 mm in the axial direction, and the planar shape of each independent heating unit 10 is a rectangle having an axial direction of 5 mm and 20 mm in a direction orthogonal to the axial direction. 58, and there is a gap of 1 mm between adjacent heat generating parts. Each heating element is provided with an electrode 11 so that power can be supplied independently. The heat generating part 10 and the electrode 11 are formed on the insulating layer 12. All of the heat generating part 10 and part of the electrode 11 are covered with an insulating layer 13. The resistance value of each heat generating part 10 is 480Ω, and when power is supplied at a voltage of 100V, a heat generation amount of 20.8 W is obtained.

  The heating element 4 is a polyimide precursor containing 32.4 parts by weight of graphite powder (GR-15, manufactured by Nippon Graphite) as conductive particles on a polyimide film (Upilex-S, manufactured by Ube Industries) having a thickness of 50 μm as the insulating layer 12. A paste prepared by adding the solution RC5063 (made by IST) to 200 parts by weight and then passing through a three-roll mill three times is printed in the shape of the heating unit 10 in FIG. And dried. Next, 47.1 parts by weight of silver powder (AgC-A, manufactured by Fukuda Metal Foil Powder) was added to 50 parts by weight of the polyimide precursor solution RC5063 and stirred for 15 minutes, and then 25 parts by weight of N was added to the silver powder-containing polyimide precursor solution. -Screen printing of paste obtained by adding 0.022 parts by weight of 2-di-n-butylamino-4,6-dimercapto-1,3,5-triazine in methyl-pyrrolidone and stirring for 8 hours In this way, it was printed in the shape of the electrode part 11 in FIG. 4 and dried. Next, the polyimide precursor solution RC5063 is printed on the shape of the insulating layer 13 in FIG. 4 by screen printing and dried, then fixed to a tenter and heated to 400 ° C. in a baking furnace over 6 hours. After being held at 400 ° C. for 15 minutes, it was cooled and taken out to produce a heating element 4.

  The heat transfer member 3 is a semi-cylindrical shape having a total axial length of 360 mm, a thickness of 0.3 mm, and a radius of 15 mm and is made of SUS304 material. The heating element 4 described above was adhered to the inner surface of the heat transfer member 3 with a heat-resistant adhesive (SKYBOND800, manufactured by IS Corporation). A power supply line 15 is connected to each electrode portion 11 of the heating element 4 from a power supply device 14. The power supply device 14 was connected to a heated body width information output device 16 that outputs width information of the heated body. The heated body width information output device 16 that outputs the width information of the heated body detects the width of the heated body 5 with a sensor and outputs the detected width to the power supply device 14.

<Control>
When the heated member is supplied and printing is started, the size information of the heated body is detected by a sensor disposed in the heated body introducing portion, and the heated body width information output device 16 sends the information to the power supply device 14. Entered. Further, temperature sensors are installed on the surfaces of the heating element 4 and the fixing belt 8, and detected temperature information is input to the power supply device 14. When the printing is started, the power supply device 14 supplies power to all the heat generating units 10 through the power supply line 15 and the power supply electrode 11 to raise the temperature of the fixing device, and promptly based on temperature information from the temperature sensor. The temperature is controlled so that fixing can be started. Subsequently, when the passage of the heated body 5 is started, the power supply device 14 causes the heated body 5 to be out of the plurality of independent heating units 10 so as to supply an amount of heat that only supplements the amount of heat that the heated body 5 brings out. Additional electric power is supplied to the heat generating part 10 of the passing part. At this time, the power supply is controlled based on the temperature information from the temperature sensor so that the temperature is suitable for fixing.

  First, 30 sheets of A3-size paper (paper width 298 mm) on which unfixed toner was placed were continuously passed through the fixing device configured as described above. The paper size information obtained by the heated object width information output device 16 to be output is sent to the power supply device 14, and as a result, the power supply device 14 supplies power to all the heat generating units 10 to generate heat. As a result, good fixing performance was obtained. The power consumption required to fix one sheet of paper at this time was about 0.45 Whr.

  Next, 40 sheets of A4 size paper (sheet width 210 mm) on which unfixed toner was placed were passed continuously for 1 minute. Information on the sheet size obtained by the heated body width information output device 16 to be output is sent to the power supply device 14, which supplies power only to the heat generating portions 10 in the central 40 locations to generate heat. It was. As a result, good fixing performance was obtained. The power consumption required to fix one sheet at this time was about 0.25 Whr.

  Next, 40 postcards (paper width 100 mm) on which unfixed toner was placed were passed continuously for 1 minute. Information on the sheet size obtained by the heated body width information output device 16 to be output is sent to the power supply device 14, and as a result, the power supply device 14 supplies power only to the heat generating portions 10 in the center 20 to generate heat. It was. As a result, good fixing performance was obtained. The power consumption required to fix one sheet at this time was about 0.13 Whr.

  Next, 60 business cards (paper width 55 mm) on which unfixed toner was placed were passed continuously for 1 minute. The paper size information obtained by the heated body width information output device 16 that outputs the heated body width information is sent to the power supply device 14, and as a result, the power supply device 14 is supplied only to the heating units 10 at the 12 central locations. Electric power was supplied to generate heat. As a result, good fixing performance was obtained. The power consumption required to fix one sheet at this time was about 0.05 Whr.

  A fixing test was performed in the same manner as in Example 1 except that the planar shape of the heating element 4 was changed to the shape shown in FIG. The heating element 4 has a total length of 360 mm in the axial direction, and the planar shape of each independent heating unit 10 has a side length w parallel to the substantially axial direction of 5 mm and a side length in the direction perpendicular to the substantially axial direction. It is a rectangle whose l is 20 mm, and it rotates around the center of gravity of each heat generating part 10 and its rotation angle θ is 10 °. There is a gap d of 1 mm between the adjacent heat generating portions 10, and d ≦ sin θ (l * cos θ−w * sin θ) = 3.27 mm is satisfied. In any case, good fixing performance was obtained, and the image quality was particularly good.

  A fixing test was performed in the same manner as in Example 1 except that the planar shape of the heating element 4 was changed to the shape shown in FIG. The heating element 4 has a total length in the axial direction of 360 mm, and the planar shape of each independent heating unit 10 has a side length w of 3 mm parallel to the substantially axial direction and a side length in a direction perpendicular to the substantially axial direction. It is a rectangle whose l is 20 mm, and it rotates around the center of gravity of each heat generating part 10, and its rotation angle θ is 45 °. There is a gap d of 3 mm between the adjacent heat generating portions 10, and d ≦ sin θ (l * cos θ−w * sin θ) = 8.5 mm. In any case, good fixing performance was obtained, and the image quality was particularly good.

  A fixing test was performed in the same manner as in Example 1 except that the planar shape of the heating element 4 was changed to the shape shown in FIG. The heating element 4 has a total length of 360 mm in the axial direction, and the planar shape of each independent heating unit 10 has a side length w parallel to the axial direction of 20 mm and a side length l in a direction perpendicular to the axial direction. Is 20 mm, and the side l in the direction perpendicular to the substantially axial direction of each heat generating portion 10 rotates about the center of gravity, and the rotation angle θ is 10 °. There is a gap d of 1 mm between the adjacent heat generating portions 10 and d ≦ sin θ (l * cos θ−w * sin θ) = 6.3 mm is satisfied. In any case, good fixing performance was obtained, and the image quality was particularly good.

<Fixing device>
FIG. 1 shows the fixing device used. The fixing device includes a pressure roller 1, a fixing film 2 and a heating element 4, and has a heat transfer member 3 between the heating element and the fixing film 2. The heat generating member 4 and the heat transfer member 3 are laminated, and the heat transfer member 3 is disposed in contact with the inner surface of the fixing film 2 and in pressure contact with the pressure roller 1.

  Using this fixing device, a fixing test was conducted by the heating element and control shown in Example 2. In any of the papers, good fixing performance was obtained, and particularly the image quality was good.

  12.1 parts by weight of vapor-grown carbon fiber (VGCF-H, manufactured by Showa Denko) as conductive particles on a polyimide film (UPILEX-S, manufactured by Ube Industries) having a thickness of 50 μm as the insulating layer 12, a polyimide precursor A paste prepared by adding the solution RC5063 (made by IST) to 200 parts by weight and then passing through a three-roll mill three times is printed in the shape of the heating unit 10 in FIG. Thereafter, the fixing test was conducted in the same manner as in Example 1 except that the heating element prepared in the same manner as in Example 1 was used. In any case, good fixing performance was obtained.

  164 parts by weight of tungsten carbide (WC10, manufactured by Allied Material) as a conductive particle on a polyimide film (UPILEX-S, manufactured by Ube Industries) having a thickness of 50 μm as the insulating layer 12 and a polyimide precursor solution RC5063 (IST, Inc.). (Product made) After adding 200 parts by weight, a heat-generating paste prepared by passing three roll mills three times was printed on the shape of the heat-generating part 10 in FIG. 4 by screen printing, and then dried in a drying furnace. A fixing test was conducted in the same manner as in Example 1 except that a heating element prepared in the same manner as in Example 1 was used. In any case, good fixing performance was obtained.

(Comparative Example 1)
The fixing test for various papers was carried out as in Example 1 except that the planar shape of the heating element was a shape having one heating part that was 350 mm long in the axial direction and 20 mm long in the direction orthogonal to the axial direction. As a result, good fixing performance was obtained for A3 size paper, but for A4 size paper, postcards and business cards, a fixing portion was formed because of the high temperature inside the fixing device during the fixing operation. The operation was unavoidable, and only about 5 sheets could be fixed per minute. The power consumption required for fixing one sheet is about 0.45 Whr for A3 size paper, about 0.6 Whr for A4 size paper, about 0.4 Whr for postcards, and about 0.00 Whr for business cards. 4 Whr. In postcards and business cards, as the overheated part cooled, the temperature of the paper passing part also decreased, and it was necessary to heat it again to the fixing temperature.

  The fixing device of the present invention can be suitably used for an electrophotographic copying machine, a laser beam printer, and the like.

DESCRIPTION OF SYMBOLS 1 Pressure roller 2 Fixing film 3 Heat transfer member 4 Heat generating body 5 Heated body 6 Unfixed toner 7 Fixing roller 8 Fixing belt 9 Fixing roller 10 Heat generating part 11 Feeding electrode 12 Insulating layer 13 Insulating layer 14 Power supply device 15 Power supply Line 16 Heated object width information output device

Claims (10)

A fixing device including a control device that supplies power to a necessary circuit and a heating element that generates heat by the power supplied from the control device;
The heating element is composed of a plurality of independent heating parts including at least polyimide, and electric power is supplied to the electrodes of the heating parts individually provided by the control device according to the size of the heating object in each heating part. A fixing device.   The fixing device according to claim 1, wherein the plurality of independent heat generating portions have a rectangular shape.   3. The fixing device according to claim 1, wherein the heat generating portions are formed by arranging the centers of gravity of the heat generating portions in a straight line.   The fixing device according to claim 3, wherein the heat generating portion is rotated in the same direction by substantially equal angles around the center of gravity.   The fixing device according to claim 4, wherein the plurality of independent heat generating portions have the same shape. The fixing device according to claim 5, wherein the heat generating portion satisfies d ≦ sin θ (l cos θ−w sin θ). (0 ° <θ <90 °, d> 0)
d: Distance between adjacent heat generating portions θ: Angle rotated about the center of gravity as an axis l: Length of sides facing one direction of the square w: Length of remaining sides of the square facing each other   The fixing device according to claim 1, wherein an insulating layer is provided on at least one surface of the heat generating portion.   The fixing device according to claim 1, wherein a heat transfer member is provided on at least one surface of the insulating layer.   9. The fixing device according to claim 8, wherein the heat transfer member is at least one selected from stainless steel, aluminum, nickel, copper, alumina, aluminum nitride, boron nitride, silicon nitride, and graphite.   The fixing device according to claim 1, wherein the heat generating portion is formed by screen printing or a metal mask.