JP2013097186A - Heating body and image heating device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent burning of a plurality of through-holes and conduction failure resulting from this, in a heating body that supplies power to a heat generation resistance body via the through-holes, formed in the substrate.SOLUTION: The heating body has conductive parts 12m and 12n electrically connected to the heat generation resistance body 12c provided along the longitudinal direction of a slender substrate 12a that is electrically insulative. The heating body also has electrodes 12f and 12h opposite to the conductive parts via the substrate in the direction of the thickness of the substrate. The substrate is provided with the plurality of through-holes 12i, 12j, 12k, and 12l for electrically connecting the conductive parts 12m and 12n and the electrodes 12f and 12h. The through-holes are disposed such that the distances d1, d2, d3, and d4 between these through-holes and power supply contacts 16b and 16f electrically connected to the electrodes are substantially equal.

Description

  The present invention relates to a heating element suitable for use as a ceramic heater used in a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer.

  Image forming apparatuses employing an electrophotographic system have been increased in speed, function, and color, and various printers, copiers, and the like are on the market.

  An electrophotographic copying machine or printer is equipped with a fixing device that heats and fixes an unfixed toner image formed on a recording material on the recording material. One of the heating methods in the fixing device is a film heating method.

  With the film heating method, a ceramic heater is placed on the inner surface of the tubular film, a pressure roller is placed at the opposite position of the ceramic heater across the tubular film, and the fixing film and the recording material are brought into close contact with each other. In this method, the heat of the heater is applied to the recording material. The tubular film (fixing film) is configured based on a heat-resistant resin or metal.

  The ceramic heater used in the film heating type fixing device includes a heating resistor made of an electric resistor on a ceramic heater substrate, a power supply electrode made of silver, an insulation made of glass for protecting the heating resistor, etc. Often composed of layers. In many cases, the power supply means to the ceramic heater is performed by bringing a connector having a power supply contact into pressure contact with an electrode on the heater substrate to form an electrical conduction path.

  In ceramic heaters, the heating resistor and electrodes are often formed on the same surface of the heater substrate. However, the heater substrate is used for the purpose of cost reduction and substrate width reduction by using a general-purpose connector. May be formed on opposite sides of each other. In the ceramic heater having such a configuration, a configuration is used in which a through hole is formed in the heater substrate to form a conduction path between the heating resistor and the electrode.

  Patent Document 1 discloses a ceramic heater in which resistance heating elements having different heat generation regions are formed on both surfaces of a heater substrate, and power can be supplied from one surface using a through hole. When a small-size recording material is continuously printed at the same print interval as a large-size recording material with a printer equipped with a film heating type fixing device, the area through which the recording material of the ceramic heater does not pass (non-paper-passing area) increases excessively. It is known to increase the temperature (temperature increase of the non-sheet passing portion).

  In the configuration of the ceramic heater of Patent Document 1, as a countermeasure against a problem called non-sheet passing portion temperature rise, heating resistors having different lengths are provided on both sides of the heater substrate, and each is used properly according to the paper size. Further, when the two heating resistors are formed on the same surface of the heater substrate, the width of each heating resistor and the distance for securing the insulation between the two heating resistors, Although it is necessary to widen the width, it is possible to prevent the width of the substrate from being increased by allocating to the front and back surfaces of the substrate.

  By the way, in the ceramic heater that supplies power to the heating resistors on both sides of the heater substrate through the through hole as described above, it is necessary to pass a large current compared to a general integrated circuit device. Abnormal heat generation may cause burning and poor conduction.

  Patent Document 2 discloses a configuration that prevents a conduction failure due to burning of a through hole by using a plurality of through holes when power is supplied to the heating resistors on both sides of the heater substrate via the through holes. ing.

JP 2002-299014 A JP-A-4-185455

  As described above, in ceramic heaters that supply heat to a heating resistor via through holes, it is required to prevent burning of the through holes and consequent conduction failure, and power is supplied via multiple through holes. Even in the case of performing the above, further improvement is demanded.

  An object of the present invention is to provide a heating element that feeds power to a heating resistor through a plurality of through-holes formed in a substrate. An object of the present invention is to provide an image heating apparatus including a body.

  In order to achieve the above object, a representative configuration of the heating body according to the present invention includes an electrically insulative and elongated substrate, and one surface of the substrate provided along the longitudinal direction of the substrate by energization. A heating resistor that generates heat; a first conductor that is electrically connected to one end of the heating resistor on one side of the substrate; and a second end of the heating resistor on one side of the substrate; A second conductor that is electrically connected; a first power supply electrode that faces the first conductor across the substrate on the other surface opposite to the one surface of the substrate; A second feeding electrode facing the second conductor through the substrate on the other surface of the substrate; and a first plurality penetrating the substrate at a plurality of locations in the region of the first conductor. A first through hole that electrically connects the first power feeding electrode and the first conductor. A plurality of through-holes and a plurality of second through-holes penetrating the substrate at a plurality of locations in the region of the second conductor, and electrically connecting the second power feeding electrode and the second conductor. A plurality of second through-holes connected to each other, wherein each of the first plurality of through-holes has a distance between a power supply contact electrically connected to the first power supply electrode and approximately The second plurality of through holes are arranged so that the distances between the second plurality of through holes and the power supply contact electrically connected to the second power supply electrode are substantially equal to each other. It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, the heating body which can prevent the burning of a through hole and the conduction defect accompanying it, and an image heating apparatus provided with the heating body can be provided.

Cross-sectional schematic diagram of fixing device The figure showing the structure of the heater which concerns on Example 1. FIG. The figure showing the positional relationship of a through hole and a feed contact when connecting a feed connector to the heater according to the first embodiment The figure showing the target temperature at the time of the evaluation test of the heater which concerns on Example 1 The figure showing the through-hole position on the electrode of the heater of a comparative example The figure showing the positional relationship of a through hole and a feed contact when connecting a feed connector to the heater according to the second embodiment The figure showing the through-hole position on the electrode of the heater of a comparative example The figure showing the positional relationship of a through hole and a feed contact when a feed connector is connected to the heater according to the third embodiment. The figure showing the through-hole position on the electrode of the heater of a comparative example The figure showing the positional relationship of a heating resistor, a through hole, and a power supply contact when a power supply connector is connected to the heater according to the fourth embodiment.

[Example 1]
(1) Fixing device (image heating device)
The configuration of the fixing device will be described with reference to FIG. The fixing device is mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer, and the unfixed toner image formed on the recording material is nipped and conveyed on the recording material by the image forming unit of the image forming apparatus. Heat fixing.

  FIG. 1 is a cross-sectional schematic diagram of a fixing device as an image heating device provided with a heating body according to the present invention.

  In the following description, regarding the fixing device and the members constituting the fixing device, the longitudinal direction means a direction orthogonal to the recording material conveyance direction on the surface of the recording material. The short side direction is a direction parallel to the recording material conveyance direction on the surface of the recording material. The length is a dimension in the longitudinal direction. The width is a dimension in the short direction. Regarding the recording material, the width direction means a direction orthogonal to the recording material conveyance direction on the surface of the recording material. The width is a dimension in the width direction.

  The fixing device 1 shown in the present embodiment includes a ceramic heater (hereinafter referred to as a heater) 12 as a heating body, a cylindrical fixing film 11 as a flexible member, a pressure roller 13 as a backup member, It has a film guide 14 as a guide member. The heater 12, the fixing film 11, the pressure roller 13, and the film guide 14 are all long members in the longitudinal direction.

  The film guide 14 is formed, for example, in a substantially bowl shape with a heat-resistant resin such as PPS (polyphenylene sulfite) or LCP (liquid crystal polymer). The film guide 14 guides the rotation of the fixing film 11 with an arcuate surface on the outer side in the short direction of the film guide 14. The heater 12 is supported by a groove provided along the longitudinal direction of the film guide 14 at the center of the lower surface of the film guide 14 in the short direction. Then, the fixing film 11 is loosely fitted on the outer periphery of the film guide 14 that supports the heater 12, and both longitudinal ends of the film guide 14 are supported on the front and rear side plates (not shown) of the apparatus frame 1 of the fixing device. ing.

  The pressure roller 13 includes a round shaft-shaped cored bar 13a, an elastic layer 13b provided on an outer peripheral surface between shafts provided at both longitudinal ends of the cored bar 13a, and an outer peripheral surface of the elastic layer 13b. And a release layer 13c provided on the substrate. The material of the cored bar 13a is a metal material such as iron or aluminum. The material of the elastic layer 13b is silicone rubber. The material of the release layer 13c is a fluororesin such as PFA.

  The pressure roller 13 is disposed so as to face the heater 12 with the fixing film 11 interposed therebetween, and shafts at both ends in the longitudinal direction of the cored bar 13a are provided with bearings (not shown) on the front and rear side plates of the apparatus frame 1. It is supported so that it can rotate through. The bearing is urged by a pressure spring (not shown) in a direction perpendicular to the bus line direction of the fixing film 11 to press the pressure roller 13 to the heater 12 via the fixing film 11. As a result, the elastic layer 13b of the pressure roller 13 is elastically deformed toward the metal core 13a, and a fixing nip portion (nip) having a predetermined width is formed between the outer peripheral surface (surface) of the pressure roller 13 and the outer peripheral surface (surface) of the fixing film 11. Part) N is formed.

  The thickness of the fixing film 11 is preferably about 20 μm or more and 1000 μm or less in order to ensure good thermal conductivity. As the fixing film 11, a cylindrical single layer film made of a material such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether), PPS (polyphenylene sulfide) can be used.

  Alternatively, a composite film having a tubular base film made of PI, PAI, PEEK, PES or the like on the surface of a tubular base film such as PTFE, PFA, FEP or a tube provided as a release layer can be used. Here, PI is polyimide, PAI is polyamideimide, PEEK is polyetheretherketone, PES is polyethersulfone, and PTFE / PFA / FEP is a tetrafluoroethylene / hexafluoropropylene copolymer.

  In this example, a fixing film 11 having a total thickness of 75 μm formed by forming a 15 μm PFA coating film on a PI having a diameter of 24 mm, a length of 240 mm, and a thickness of 60 μm was used. As the pressure roller 13, a roller having a diameter of 25 mm, a length of 260 mm, and a pressure hardness of 50 ° (measured by Asker C-type hardness meter when loaded with 500 g) was used.

(2) Heater (heating body) 12
The configuration of the heater 12 will be described with reference to FIG. 2A is a schematic configuration diagram of the heater 12 when the heater 12 is viewed from the fixing nip portion N side, and FIG. 2B is a schematic configuration diagram of the heater 12 when the heater 12 is viewed from the side opposite to the fixing nip portion N side. It is. (C) is a longitudinal cross-sectional structure schematic diagram which passes along the through hole 12i (12j) and the through hole 12k (12l) of the heater 12. FIG.

  The heater 12 has an elongated heater substrate (hereinafter referred to as a substrate) 12a that is electrically insulating.

  On one surface (hereinafter referred to as a surface) of the substrate 12a on the fixing nip portion N side, a first heating resistor (hereinafter referred to as a heating resistor) 12b that generates heat when energized is along the longitudinal direction of the substrate 12a. It is provided. A first feeding electrode 12f that is electrically connected to one longitudinal end of the heating resistor 12b is provided inside one longitudinal end of the substrate, and the heating resistor is disposed inside the other longitudinal end of the substrate. A second power feeding electrode 12h that is not physically in contact with the other end in the longitudinal direction of 12b is provided. Further, a third power supply electrode 12g that is electrically connected to the heating resistor 12b is provided inside the other end portion in the longitudinal direction of the substrate 12a. The third power supply electrode 12g is disposed on the inner side in the longitudinal direction of the substrate 12a than the second power supply electrode 12h.

  Furthermore, the surface of the substrate 12a is provided with a heat generating resistor 12b and an insulating surface protective layer 12d that covers the connecting portion of the first power supply electrode 12f and the second power supply electrode 12g between the heat generating resistor 12b. .

  On the other surface of the substrate 12a on the fixing nip portion N side (hereinafter referred to as a back surface), a second heat generating resistor (hereinafter referred to as a heat generating resistor) 12c that generates heat when energized extends along the longitudinal direction of the substrate 12a. It is provided. The heating resistor 12c is formed so as to be shorter than the heating resistor 12b, and is disposed at the approximate center in the longitudinal direction of the substrate 12a. A first conductor 12m that is electrically connected to one longitudinal end of the heating resistor 12c is provided inside one longitudinal end of the substrate, and the heating resistor is disposed inside the other longitudinal end of the substrate. A second conductor 12n that is electrically connected to the other end of the longitudinal direction of 12c is provided. The first conductor 12m is disposed so as to face the first power supply electrode 12m through the substrate 12a in the thickness direction of the substrate 12a. The second conductor 12n is disposed so as to face the second power supply electrode 12h through the substrate 12a in the thickness direction of the substrate 12a.

  Furthermore, an insulating surface protective layer 12e is provided on the back surface of the substrate 12a to cover the connecting portion between the heating resistor 12c and the heating resistor 12e of the first conductor 12m and the second conductor 12n. .

  The first power supply electrode 12f and the first first conductor 12m are electrically connected by two through holes (first through holes) 12j and 12i that penetrate the substrate 12a in the thickness direction of the substrate 12a. It is connected to the. The second power supply electrode 12h and the second conductor 12n are electrically connected by two through holes (second through holes) 12k and 12l penetrating the substrate 12a in the thickness direction of the substrate 12a. . Accordingly, the first power supply electrode 12f is used as a common electrode for the two heat generating resistors 12b and 12c, and the second power supply electrode 12h is used as a power supply electrode for supplying power to the heat generating resistor 12c from the surface of the substrate 12a. .

  Power supply connectors 16a, 16e, and 16c (see FIG. 3) as power supply members are electrically connected to the first power supply electrode 12f, the second power supply electrode 12h, and the third power supply electrode 12g, respectively. . As a result, the first power supply electrode 12f, the second power supply electrode 12h, and the third power supply electrode 12g are energized from the power supply connectors 16a, 16e, and 16c, and the heating resistors 12b and 12c generate heat.

  In the following description, for simplification of description, the first power supply electrode 12f, the second power supply electrode 12h, and the third power supply electrode 12g are referred to as electrodes, respectively, and the first conductor 12m, Each of the second conductors 12n is referred to as a conductor.

  As the material of the substrate 12a, ceramics such as alumina and aluminum nitride can be used. In this example, an alumina substrate having a width of 7 mm in the short direction, a length of 280 mm in the longitudinal direction, and a thickness of 1 mm was used.

As the material of the heating resistors 12b and 12c, an electric resistance material such as Ag / Pd, RuO ₂ , Ta ₂ N, graphite, SiC, LaCrO ₃ or the like is applied by screen printing in a linear shape or a linear shape. it can. Here, Ag / Pd is silver palladium, RuO ₂ is ruthenium oxide, Ta ₂ N is tantalum nitride, SiC is silicon carbide, and LaCrO ₃ is lanthanum chromite.

  In this example, both the heating resistors 12b and 12c were formed by screen printing and kneaded with Ag / Pd, glass powder, and organic binder. The length s of the heating resistor 12c was set to 115 mm, and the resistance value was set to 30Ω. The length w of the heating resistor 12b was set to 230 mm, and the resistance value was set to 15Ω. The heating resistor 12c has a length corresponding to a small size recording material (recording paper) having a small recording material width. The heating resistor 12b has a length corresponding to a large recording material (recording paper) having a recording material width larger than that of the recording material of size.

  The surface protective layers 12e and 12f are formed for the purpose of ensuring insulation between the heating resistors 12b and 12c and the surface of the heater 12, and in this embodiment, insulating glass was formed to 80 μm by screen printing.

  The electrodes 12f, 12g and 12h and the conductors 12m and 12n can be formed by screen printing using a conductive paste mainly composed of silver (Ag), platinum (Pt) or the like. Alternatively, it can be formed by screen printing using a conductive paste mainly composed of gold (Au), silver platinum (Ag / Pt) alloy, silver palladium (Ag / Pd) alloy, or the like. In this example, silver was formed by screen printing on any electrode and conductor. Further, since the electrodes 12f, 12g, 12h and the conductors 12m, 12n are provided for the purpose of supplying power to the heating resistors 12b, 12c, the electric resistance is made sufficiently smaller than that of the heating resistors 12b, 12c.

  As a method of forming the through holes 12i, 12j, 12k, and 12l, through holes are formed in the substrate 12a by laser scribing at two places (plural places) in the region of the electrodes 12f, 12h. A conductive path can be formed by providing a conductive paste mainly composed of silver (Ag), platinum (Pt), gold (Au) or the like inside the through hole. Alternatively, a conductive path can be formed by providing a conductive paste mainly composed of silver platinum (Ag / Pt) alloy, silver palladium (Ag / Pd) alloy, or the like inside the through hole. In this example, a through hole was formed with a diameter of 0.3 mm by laser scribing, and a conductive path was formed between the electrode and the conductor by providing a silver conductive paste inside.

(3) Heat Fixing Operation of Fixing Device As shown in FIG. 1, the fixing device of the present embodiment is pressed by rotating the cored bar 13a of the pressure roller 13 by the rotation drive of a motor (not shown). The roller 13 rotates in the direction indicated by the arrow b. The rotation of the pressure roller 13 is transmitted to the fixing film 11 by the frictional force between the surface of the pressure roller 13 and the surface of the fixing film 11 at the fixing nip portion N. As a result, the fixing film 11 rotates (moves) in the direction indicated by the arrow a following the rotation of the pressure roller 13 while the inner peripheral surface (inner surface) of the fixing film 11 is in contact with the surface protective layers 12e and 12f of the heater 12. )

  When heat-fixing an unfixed toner image on a large-sized recording material, current is supplied to the electrodes 12f and 12g of the heater 12 via power supply connectors 16a and 16c from an energization control unit (not shown), and the heating resistor 12b is connected. Fever. As a result, the heater 12 is rapidly heated to heat the fixing film 11. The temperature of the heater 12 is detected by a temperature detection element (temperature detection member) 15 such as a thermistor provided at a predetermined position on the surface protective layer 12e on the back side of the substrate 12a. The energization control unit controls the energization amount to the heater 12 based on the output signal from the temperature detection element 15 so as to maintain the heater 12 at a predetermined fixing temperature (target temperature).

  In a state where the motor is driven to rotate and the heater 12 is maintained at a predetermined fixing temperature, a large size recording material P carrying an unfixed toner image t is introduced into the fixing nip N with the toner image carrying surface facing upward. The The recording material P is nipped between the surface of the fixing film 11 and the surface of the pressure roller 13 in the fixing nip portion N and is conveyed (nipped and conveyed) in that state. In this conveyance process, the toner image t on the recording material P is heated and melted by the heater 12 through the fixing film 11 and is heated and fixed on the recording material by being pressurized at the fixing nip N. The recording material P on which the toner image is heat-fixed is separated from the surface of the fixing film 11 and discharged from the fixing nip N.

  When heat-fixing an unfixed toner image on a small-size recording material, current is applied to the electrodes 12f and 12h of the heater 12 via power supply connectors 16a and 16e from an energization control unit (not shown), and the heating resistor 12c is connected. Fever. As a result, the heater 12 is rapidly heated to heat the fixing film 11. The temperature of the heater 12 is detected by the temperature detection element 15. The energization control unit controls the energization amount to the heater 12 so as to maintain the heater 12 at a predetermined fixing temperature based on an output signal from the temperature detection element 15.

  In a state where the motor is driven to rotate and the heater 12 is maintained at a predetermined fixing temperature, a small size recording material P carrying an unfixed toner image t is introduced into the fixing nip N with the toner image carrying surface facing upward. The The recording material P is nipped between the surface of the fixing film 11 and the surface of the pressure roller 13 in the fixing nip portion N and is conveyed (nipped and conveyed) in that state. In this conveyance process, the toner image t on the recording material P is heated and melted by the heater 12 through the fixing film 11 and is heated and fixed on the recording material by being pressurized at the fixing nip N. The recording material P on which the toner image is heat-fixed is separated from the surface of the fixing film 11 and discharged from the fixing nip N.

(4) Positional relationship between the heater through-hole and the power supply contact of the power supply connector The heater through-hole of this embodiment is a power supply contact when a power supply connector having a power supply contact (hereinafter referred to as a connector) is connected to an electrode. And the circumference of the through hole are formed at positions where the two through holes in the same electrode are substantially equal. The aim is to suppress degradation of the through hole by equally dividing the current amount flowing through the two through holes and equalizing them.

  The positional relationship between the through hole and the power supply contact in this embodiment will be described with reference to FIG. FIG. 3 is a diagram showing the positional relationship between the through hole and the power supply contact when the connectors 16a, 16c, and 16e are connected to the heater 12. As shown in FIG. (A) is a diagram showing the positional relationship between the through holes 12i, 12j, 12k, and 12l and the power supply contacts 16b, 16d, and 16f when viewed from the downstream side in the recording material conveyance direction. (B) is a diagram showing the positional relationship between the through holes 12i, 12j, 12k, and 12l and the power supply contacts 16b, 16d, and 16f when viewed from the fixing nip portion N side.

  (C) is a diagram showing the positional relationship between the through holes 12i, 12j and the power supply contact 16b when viewed from the electrode 12f side. (D) is a diagram showing the positional relationship between the through holes 12i, 12j and the power supply contact 16b in the electrode 12f when viewed from the fixing nip N side. (E) is a diagram showing the positional relationship between the through holes 12k and 12l and the power supply contact 16f in the electrode 12h when viewed from the fixing nip N side.

  The connectors 16a, 16c, and 16e are provided with power supply contacts 16b, 16d, and 16f, respectively, that are brought into electrical contact with the electrodes 12f, 12g, and 12h on the heater 12 to form electrical continuity. In this embodiment, the connectors 16a, 16c and 16e are inserted into the heater 12 supported by the film guide 14 from the right side in FIG. To prevent positioning and disconnection. Thus, the position of the power supply contacts 16b, 16d, and 16f with respect to the electrodes 12f, 12g, and 12h on the heater 12 can be determined. With such a configuration, the distance relationship between the power supply contacts 16b, 16d, and 16f and the respective through holes 12i, 12j, 12k, and 12l was determined.

  As shown in FIG. 3D, if the shortest distance between the power supply contact 16b and the peripheral portion of the through hole 12i is defined as d1, and the shortest distance between the power supply contact 16b and the peripheral portion of the through hole 12j is defined as d2, d1 and d2 Are configured to be almost equal. As shown in FIG. 3E, if the shortest distance between the power supply contact 16f and the peripheral portion of the through hole 12k is defined as d3, and the shortest distance between the power supply contact 16f and the peripheral portion of the through hole 12l is defined as d4, d3 and d4. Are configured to be almost equal. In this embodiment, both d1 and d2 are set to 2 mm, and d3 and d4 are both set to 2 mm.

  Next, in order to confirm the effect of using the above configuration, the reliability of energization of the heater 12 was tested. In the test method, with the heater 12 incorporated in the fixing device, the temperature target as shown in FIG. The reliability was evaluated by the number of test cycles when the through-hole resistance increased and the continuity decreased. Further, as a comparative example, a heater having an electrode configuration in which the through hole positions are d1> d2 and d3> d4 as shown in FIG. 5 was similarly tested. In the heater of this comparative example, d1 = 2.3 mm, d2 = 1.8 mm, d3 = 2.3 mm, d4 = 1.8 mm, d1 = 2.5 mm, d2 = 1.5 mm, d3 = 2.5 mm and d4 = 1.5 mm were compared. The respective evaluation results are shown in Table 1.

  As shown in Table 1, the heater 12 has a configuration of d1 = d2 and d3 = d4, compared to a configuration of d1 = 2.5 mm, d2 = 1.5 mm, d3 = 2.5 mm, and d4 = 1.5 mm. The number of tests is 1.4 times longer. That is, by adopting the configuration of d1 = d2 and d3 = d4 like the heater 12 of the present embodiment, the reliability of energization of the heater using the through hole could be improved. Further, in the case where d1 = 2.3 mm, d2 = 1.8 mm, d3 = 2.3 mm, and d4 = 1.8 mm, the difference between the configuration of d1 = d2 and d3 = d4 was only 200 times. Therefore, a sufficient difference in distance between the two through holes and the distance between the through hole and the power supply contact can be obtained by keeping it to about 0.5 mm.

  In this evaluation, in the configuration where d1> d2 and d3> d4, the through-holes close to each other tend to deteriorate first and the resistance rises. It was. However, in the configuration of d1 = d2 and d3 = d4, since the current flowed in a well-balanced manner, the number of times of deterioration could be increased, and it was confirmed that the aimed effect was obtained. Therefore, the heater 12 of the present embodiment can prevent the through hole from burning and the accompanying conduction failure.

  This test is a mode in which the reliability of the heater is evaluated in an accelerated manner, and even in the heater of this example, there was a tendency for conduction to decrease. However, when the heater of this embodiment was used for the fixing device of the image forming apparatus, no increase in resistance due to the deterioration of the through hole was observed in the same number of times, and no problem in actual use was confirmed.

  Even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the one end in the longitudinal direction of the substrate 12a in the heater 12 of the present embodiment, the same effect can be obtained. Alternatively, even if the electrode 12f, the electrodes 12h, 12g, and 12h and the conductors 12m and 12n are disposed inside the other end portion in the longitudinal direction of the substrate 12a, the same effect can be obtained.

  Even if the heating resistor 12b and the electrode 12g are not provided in the heater 12 of the present embodiment, the same operational effects can be obtained. In this case, the electrode 12f is not used as a common electrode, but is used as a feeding electrode that feeds power to the heating resistor 12c from the surface of the substrate 12a. The configuration of the heater 12 in this case includes a substrate 12a, electrodes 12f and 12h, a heating resistor 12c, conductors 12m and 12n, and through holes 12i, 12j, 12k, and 12l, and d1 = d2 , D3 = d4. As a result, it is possible to prevent the through hole from burning and the accompanying conduction failure.

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the same effect can be obtained even if the heating resistor 12c is set to the same length as the heating resistor 12b. .

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside one end portion in the longitudinal direction of the substrate 12a. The same effect can be obtained. Alternatively, even if the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside the other end portion in the longitudinal direction of the substrate 12a, the same effect can be obtained.

[Example 2]
Another example of the heater will be described. As shown in FIGS. 6A and 6B, the heater of the present embodiment has three through holes (first plurality of holes) penetrating the electrode 12f and the conductor 12m through the substrate 12a in the thickness direction of the substrate 12a. Through-holes) 12j, 12i, and 12o. Similarly, the electrode 12h and the conductor 12n are electrically connected through three through holes (second plural through holes) 12k, 12l, and 12p that penetrate the substrate 12a in the thickness direction of the substrate 12a. Except for this point, the configuration is the same as that of the heater 12 of the first embodiment.

  FIG. 6 shows the configuration of the heater of this example and the positional relationship between the through hole and the power supply contact. (A) is a diagram showing the positional relationship between the through holes 12i, 12j, 12o, 12k, 12l, and 12p and the power supply contacts 16b, 16d, and 16f when viewed from the downstream side in the recording material conveyance direction. (B) is a diagram showing the positional relationship between the through holes 12i, 12j, 12o, 12k, 12l, and 12p and the power supply contacts 16b, 16d, and 16f when viewed from the fixing nip N side.

  In the same figure, (C) is a diagram showing the positional relationship between the through holes 12i, 12j, 12o and the power supply contact 16b when viewed from the electrode 12f side. (D) is a diagram showing the positional relationship between the through holes 12i, 12j, 12o and the power supply contact 16b in the electrode 12f when viewed from the fixing nip N side. (E) is a diagram showing the positional relationship between the through holes 12k, 12l, 12p and the power supply contact 16f in the electrode 12h when viewed from the fixing nip N side.

  In the present embodiment, through holes 12o and 12p are added to the heater of the first embodiment, and the distance relation when the shortest distance between the peripheral portion of each through hole and the feeding contact is d5 and d6 is as follows. , D1 = d2 = d5, d3 = d4 = d6. The distances were set to 1.8 mm for d1, d2, and d5, and 1.6 mm for d3, d4, and d6, respectively.

  In order to confirm the effect of using the above configuration, the reliability of energization of the heater 12 was tested under the same conditions as in Example 1. Further, as a comparative example, a heater that satisfies d1> d5> d2 and d3> d6> d4 as shown in FIG. 7 was also tested. In the heater of this comparative example, d1 = 1.8 mm, d2 = 2.0 mm, d5 = 1.5 mm, d3 = 1.6 mm, d4 = 1.8 mm, d6 = 1.3 mm were used. . Moreover, the thing set to d1 = 1.8mm, d2 = 2.3mm, d5 = 1.3mm, d3 = 1.6mm, d4 = 2.1mm, d6 = 1.1mm was used. And it compared with two heaters of the comparative example. The respective evaluation results are shown in Table 2.

  As shown in Table 2, d1 = 1.8 mm, d2 = 2.3 mm, d5 = 1.3 mm, d3 = 1.6 mm, due to the configuration of the heater 12 d1 = d2 = d5, d3 = d4 = d6, Compared to the configuration of d4 = 2.1 mm and d6 = 1.1 mm, the life can be extended 1.9 times. That is, by adopting the configuration of d1 = d2 = d5 and d3 = d4 = d6 like the heater 12 of the present embodiment, the reliability of energization of the heater using the through hole can be improved. In the case where d1 = 1.8 mm, d2 = 2.0 mm, d5 = 1.5 mm, d3 = 1.6 mm, d4 = 1.8 mm, d6 = 1.3 mm, d1 = d2, d3 = d4 And the difference of 300 times. Therefore, even in the configuration of three through-holes, sufficient reliability can be obtained by keeping the distance difference between the through-hole and the feeding contact point at about 0.5 mm between the closest and the remotest one. It is possible to set it to an equal distance.

  In this evaluation, in the configuration of d1> d5> d2 and d3> d6> d4, immediately after the through hole with a short distance deteriorates and the resistance rises, the through hole with a long distance also deteriorates due to current concentration. The tendency to do was seen. However, in the configuration of d1 = d2 = d5 and d3 = d4 = d6, since the currents flowed in a well-balanced manner, the number of times of deterioration can be increased, and it was confirmed that the aimed effect was obtained. Therefore, the heater 12 of the present embodiment can also prevent the through-hole from burning and the accompanying conduction failure.

  This test is a mode in which the reliability of the heater is evaluated in an accelerated manner, and even in the heater of this example, there was a tendency for conduction to decrease. However, when the heater of this embodiment was used as a fixing device of an image forming apparatus, no increase in resistance due to deterioration of the through hole was observed in the same number of times, and no problem in practical use was confirmed.

  In addition, compared with the heater 12 of Example 1, the heater 12 of this example can extend the number of tests by 3000 times, and the effect of increasing the reliability was confirmed by increasing the number of through holes. . That is, in Example 1, the number of through holes is two, and in the present example, the number of through holes is three. However, even in a configuration in which the number of through holes is further increased, the reliability of heater energization can be improved. Is easy to imagine.

  Even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the one end in the longitudinal direction of the substrate 12a in the heater 12 of the present embodiment, the same effect can be obtained. Or even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the other end in the longitudinal direction of the substrate 12a, the same effect can be obtained.

  Even if the heating resistor 12b and the electrode 12g are not provided in the heater 12 of the present embodiment, the same operational effects can be obtained. In this case, the electrode 12f is not used as a common electrode, but is used as a feeding electrode that feeds power to the heating resistor 12c from the surface of the substrate 12a. The configuration of the heater 12 in this case includes a substrate 12a, electrodes 12f and 12h, a heating resistor 12c, conductors 12m and 12n, and through holes 12i, 12j, 12k, and 12l, and d1 = d2 = D5, d3 = d4 = d6. As a result, it is possible to prevent the through hole from burning and the accompanying conduction failure.

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the same effect can be obtained even if the heating resistor 12c is set to the same length as the heating resistor 12b. .

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside one end portion in the longitudinal direction of the substrate 12a. The same effect can be obtained. Alternatively, even if the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside the other end portion in the longitudinal direction of the substrate 12a, the same effect can be obtained.

[Example 3]
Another example of the heater will be described. The heater of the present embodiment is configured such that two power supply contacts are present on the electrodes 12f and 12h, respectively. Except for this point, the configuration is the same as that of the heater 12 of the first embodiment.

  FIG. 8 shows the configuration of the heater of this example and the positional relationship between the through hole and the power supply contact. (A) is a diagram showing the positional relationship between the through holes 12i, 12j, 12k, and 12l and the power supply contacts 16b, 16g, 16d, 16f, and 16i when viewed from the downstream side in the recording material conveyance direction. (B) is a diagram showing the positional relationship between the through holes 12i, 12j, 12k, 12l and the power supply contacts 16b, 16g, 16d, 16f, 16i when viewed from the fixing nip N side.

  (C) is a diagram showing the positional relationship between the through hole 12i and the power feeding contacts 16b and 16g when viewed from the electrode 12f side. (D) is a diagram showing the positional relationship between the through holes 12i, 12j and the power supply contacts 16b, 16g in the electrode 12f when viewed from the fixing nip N side. (E) is a diagram showing the positional relationship between the through holes 12k, 12l and the power supply contacts 16f, 16i in the electrode 12h when viewed from the fixing nip N side.

  In the heater 12 of the present embodiment, power supply contacts 16g, 16h, and 16i are added to the connectors 16a, 16b, and 16c, respectively, with respect to the configuration of the heater 12 of the first embodiment. As a result, the two power feed contacts (a plurality of power feed contacts) 16b and 16g of the connector 16a are electrically connected to the electrode 12f within the region of the electrode 12f. On the other hand, two feeding contacts (a plurality of feeding contacts) 16f and 16i of the connector 16e are electrically connected to the electrode 12h in the region of the electrode 12h. The purpose of this configuration is to improve the reliability of the conduction performance with respect to the variation in the contact state and the variation in the power feeding performance of each power feeding contact by increasing the number of the power feeding contacts existing in one electrode.

  Further, in the two electrodes 12f and 12h, the positional relationship between the through hole and the power supply contact was set so that the shortest distance from the center of the two power supply contacts to the peripheral portion of the through hole was almost equal. That is, as shown in FIG. 8D, the shortest distance between the centers of the power supply contacts 16b and 16g and the peripheral portion of the through hole 12i is d1, and the shortest distance between the centers of the power supply contacts 16b and 16g and the peripheral portion of the through hole 12j. When the distance is defined as d2, d1 and d2 are configured to be substantially equal.

  As shown in FIG. 8E, the shortest distance between the center of the power supply contacts 16f and 16i and the peripheral portion of the through hole 12k is d3, and the shortest distance between the center of the power supply contacts 16f and 16i and the peripheral portion of the through hole 12l. When d4 is defined, d3 and d4 are configured to be substantially equal. In this embodiment, both d1 and d2 are set to 2 mm, and d3 and d4 are both set to 2 mm.

  In order to confirm the effect of using the above configuration, the reliability of energization of the heater 12 was tested under the same conditions as in Example 1. Further, as a comparative example, a heater having an electrode configuration in which the through hole positions are d1> d2 and d3> d4 as shown in FIG. 9 was also tested. In the heater of this comparative example, d1 = 2.3 mm, d2 = 1.8 mm, d3 = 2.3 mm, d4 = 1.8 mm, d1 = 2.5 mm, d2 = 1.5 mm, d3 = 2.5 mm and d4 = 1.5 mm were compared. The respective evaluation results are shown in Table 3.

  As shown in Table 3, the heater 12 has a configuration of d1 = d2 and d3 = d4, compared to a configuration of d1 = 2.5 mm, d2 = 1.5 mm, d3 = 2.5 mm, d4 = 1.5 mm. The number of tests is 1.3 times longer. That is, by adopting the configuration of d1 = d2 and d3 = d4 like the heater 12 of the present embodiment, the reliability of energization of the heater using the through hole could be improved. In addition, in the configuration of the heater 12 of this embodiment in which each of the electrodes 12f and 12h has two power supply contacts, the distance difference between the through holes and the power supply contacts between the two through holes is about 0.5 mm. Sufficient reliability can be obtained by fastening. It is desirable to set an equal distance between the two through holes and between the through hole and the power supply contact. Therefore, also in the heater 12 of the present embodiment, it is possible to prevent the through hole from burning and the accompanying conduction failure.

  This test is a mode in which the reliability of the heater is evaluated in an accelerated manner, and even in the heater of this example, there was a tendency for conduction to decrease. However, when the heater of this embodiment was used for the fixing device of the image forming apparatus, no increase in resistance due to the deterioration of the through hole was observed in the same number of times, and no problem in actual use was confirmed.

  In addition, by increasing the number of power supply contacts in the heater of this example compared to the heater 12 of Example 1, the number of tests can be extended by 1000 times compared to the heater 12 of Example 1, and the number of power supply contacts can be increased. The effect of increasing the reliability of energization of the heater was confirmed. That is, in the first embodiment, the number of power supply contact points is one, and in this embodiment, the number of power supply contact points is two. However, even in a configuration in which the number of power supply contact points is further increased, the reliability of power supply to the heater can be improved. Is easy to imagine.

  Even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the one end in the longitudinal direction of the substrate 12a in the heater 12 of the present embodiment, the same effect can be obtained. Or even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the other end in the longitudinal direction of the substrate 12a, the same effect can be obtained.

  Even if the heating resistor 12b and the electrode 12g are not provided in the heater 12 of the present embodiment, the same operational effects can be obtained. In this case, the electrode 12f is not used as a common electrode, but is used as a feeding electrode that feeds power to the heating resistor 12c from the surface of the substrate 12a. The configuration of the heater 12 in this case includes a substrate 12a, electrodes 12f and 12h, a heating resistor 12c, conductors 12m and 12n, and through holes 12i, 12j, 12k, and 12l, and d1 = d2 , D3 = d4. As a result, it is possible to prevent the through hole from burning and the accompanying conduction failure.

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the same effect can be obtained even if the heating resistor 12c is set to the same length as the heating resistor 12b. .

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside one end portion in the longitudinal direction of the substrate 12a. The same effect can be obtained. Alternatively, even if the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside the other end portion in the longitudinal direction of the substrate 12a, the same effect can be obtained.

[Example 4]
Another example of the heater will be described. The heater of the present embodiment is not only the distance between the power supply contact and the through hole, but also the distance between the longitudinal end of the heating resistor and the through hole, and the other longitudinal end of the same heating resistor. The distance between the part and the through hole is configured to be substantially equal. Except for the above configuration, the configuration is the same as the heater 12 of the first embodiment.

  FIG. 10 shows the configuration of the heater of this example, the positional relationship between the through hole and the power supply contact, and the positional relationship between the end portion of the heating resistor in the longitudinal direction and the through hole. (A) is a diagram showing the positional relationship between the through holes 12i, 12j, 12k, and 12l and the power supply contacts 16b, 16g, 16d, 16f, and 16i when viewed from the downstream side in the recording material conveyance direction. (B) is a diagram showing the positional relationship between the through holes 12i, 12j, 12k, 12l and the power supply contacts 16b, 16g, 16d, 16f, 16i when viewed from the fixing nip N side.

  (C) is a diagram showing the positional relationship between the through holes 12i, 12j and the power supply contact 16b when viewed from the electrode 12f side. (D) is a diagram showing the positional relationship between the through holes 12i, 12j and the power supply contacts 16b, 16g in the electrode 12f when viewed from the fixing nip N side. (E) is a diagram showing the positional relationship between the through holes 12k, 12l and the power supply contacts 16f, 16i in the electrode 12h when viewed from the fixing nip N side. (F) is a diagram showing the positional relationship between the end of the heating resistor 12c in the longitudinal direction and the through holes 12k and 12l when viewed from the side opposite to the fixing nip N side.

  In the heater 12 of the present embodiment, as in the heater of the third embodiment, the positional relationship between the through hole and the feeding contact in the two electrodes 12f and 12h is the shortest distance from the center of the two feeding contacts to the peripheral portion of the through hole. Were set to be approximately equal.

  Further, in the two electrodes 12f and 12h, the positional relationship between the through hole and the power supply contact was set so that the shortest distance from the center of the two power supply contacts to the peripheral portion of the through hole was almost equal. That is, as shown in FIG. 10D, the shortest distance between the centers of the power supply contacts 16b and 16g and the peripheral portion of the through hole 12i is d1, and the shortest distance between the centers of the power supply contacts 16b and 16g and the peripheral portion of the through hole 12j. When the distance is defined as d2, d1 and d2 are configured to be substantially equal.

  As shown in FIG. 10E, the shortest distance between the center of the power supply contacts 16f and 16i and the peripheral portion of the through hole 12k is d3, and the shortest distance between the center of the power supply contacts 16f and 16i and the peripheral portion of the through hole 12l. When d4 is defined, d3 and d4 are configured to be substantially equal. In this embodiment, both d1 and d2 are set to 2 mm, and d3 and d4 are both set to 2 mm.

  As shown in FIG. 10F, the shortest distance between one end portion of the heating resistor 12c in the longitudinal direction and the through hole 12i is d7, and the shortest distance between the one end portion of the heating resistor 12c in the longitudinal direction and the through hole 12j. When defined as d8, d7 and d8 are both configured to be 120 mm. Further, d9 is defined as the shortest distance between the other end in the longitudinal direction of the heating resistor 12c and the through hole 12k, and d10 is defined as the shortest distance between the other end in the longitudinal direction of the heating resistor 12c and the through hole 12l. And d10 are both 130 mm.

  When the effect of using the above configuration was tested under the same conditions as in Example 1, the number of tests was 8000, which was 2000 times longer than that of Example 3.

  The heater 12 of the present embodiment is configured such that the distances d1 = d2 and d3 = d4 between the power supply contact and the through hole. Further, the distance d7 = d8 between the longitudinal end of the heating resistor 12c and the through hole and the distance d9 = d10 between the longitudinal other end of the heating resistor 12c and the through hole are set. It is configured. For this reason, the total distance of the power feeding path to the heating resistor 12c when passing through the through holes 12i and 12j in the electrode 12f is substantially equal. Further, the total distance of the power feeding path to the heating resistor 12c when passing through the through holes 12k and 12l in the electrode 12h is substantially equal. Thereby, deterioration of the through holes 12i, 12j, 12k, and 12l can be suppressed, and the reliability of energization of the heater 12 can be improved. Therefore, also in the heater 12 of the present embodiment, it is possible to prevent the through hole from burning and the accompanying conduction failure.

  This test is a mode in which the reliability of the heater is evaluated in an accelerated manner, and even in the heater of this example, there was a tendency for conduction to decrease. However, when the heater of this embodiment was used for the fixing device of the image forming apparatus, no increase in resistance due to the deterioration of the through hole was observed in the same number of times, and no problem in actual use was confirmed.

  In the first embodiment, the heater 12 having two through holes has been described. However, it can be easily imagined that the reliability of energization of the heater can be improved even in a configuration in which the number of through holes is further increased.

  Even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the one end in the longitudinal direction of the substrate 12a in the heater 12 of the present embodiment, the same effect can be obtained. Or even if the electrodes 12f, 12g, and 12h and the conductors 12m and 12n are disposed inside the other end in the longitudinal direction of the substrate 12a, the same effect can be obtained.

Even if the heating resistor 12b and the electrode 12g are not provided in the heater 12 of the present embodiment, the same operational effects can be obtained. In this case, the electrode 12f is not used as a common electrode, but is used as a feeding electrode that feeds power to the heating resistor 12c from the surface of the substrate 12a. The configuration of the heater 12 in this case includes a substrate 12a, electrodes 12f and 12h, a heating resistor 12c, conductors 12m and 12n, and through holes 12i, 12j, 12k, and 12l, and d1 = d2 , D3 = d4, d7 = d8, d9 = d10. As a result, it is possible to prevent the through hole from burning and the accompanying conduction failure.
Good can be prevented.

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the same effect can be obtained even if the heating resistor 12c is set to the same length as the heating resistor 12b. .

  Further, when the heater 12 of this embodiment is not provided with the heating resistor 12b and the electrode 12g, the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside one end portion in the longitudinal direction of the substrate 12a. The same effect can be obtained. Alternatively, even if the electrodes 12f and 12h and the conductors 12m and 12n are disposed inside the other end portion in the longitudinal direction of the substrate 12a, the same effect can be obtained.

[Other embodiments]
The fixing devices according to the first to fourth embodiments are not limited to use as a device that heat-fixes an unfixed toner image t carried by the recording material P on the recording material. For example, it can also be used as an image heating apparatus that heats an unfixed toner image to be applied to a recording material, or an image heating apparatus that heats a toner image heated and fixed on a recording material to give glossiness to the surface of the toner image.

DESCRIPTION OF SYMBOLS 1 ... Fixing device, 11 ... Fixing film, 12 ... Heater, 12a ... Heater substrate, 12b, 12c ... Heating resistor, 12f, 12g, 12h ... Electrode, 12i, 12j, 12k, 12l, 12o , 12p ... through hole, 12m, 12n ... conductor, 13 ... pressure roller, 16a, 16c, 16e ... feed connector, 16b, 16d, 16f, 16g, 16h, 16i ... feed contact, N ... ...... Fixing nip, P ... Recording material, t ... Unfixed toner image

Claims (9)

An elongated substrate having electrical insulation;
A heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first conductor electrically connected to one end of the heating resistor on one surface of the substrate;
A second conductor electrically connected to the other end of the heating resistor on one surface of the substrate;
A first power supply electrode facing the first conductor through the substrate on the other surface opposite to the one surface of the substrate;
A second power supply electrode facing the second conductor via the substrate on the other surface of the substrate;
A first plurality of through-holes penetrating the substrate at a plurality of locations in the region of the first conductor and electrically connecting the first power feeding electrode and the first conductor; Multiple through-holes,
A second plurality of through-holes penetrating the substrate at a plurality of locations in the region of the second conductor and electrically connecting the second power feeding electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes is disposed so that distances between the first power supply electrode and the power supply contact electrically connected to the first power supply electrode are substantially equal.
Each of the second plurality of through holes is disposed so that distances between the second through holes and a power supply contact electrically connected to the second power supply electrode are substantially equal. An elongated substrate having electrical insulation;
A first heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first feeding electrode electrically connected to one end of the first heating resistor on one surface of the substrate;
A second feeding electrode not physically in contact with the first heating resistor on one surface of the substrate;
A third feeding electrode electrically connected to the other end of the first heating resistor on one surface of the substrate;
A second heating resistor provided along the longitudinal direction of the substrate on the other surface opposite to the one surface of the substrate and generating heat by energization;
A first conductor facing the first feeding electrode on the other surface of the substrate through the substrate and electrically connected to one end of the second heating resistor;
A second conductor opposed to the second feeding electrode on the other surface of the substrate through the substrate and electrically connected to the other end of the second heating resistor;
A plurality of first through holes penetrating the substrate at a plurality of locations in the region of the first power supply electrode, and electrically connecting the first power supply electrode and the first conductor. Multiple through-holes,
A plurality of second through holes penetrating the substrate at a plurality of locations in the region of the second power supply electrode, and electrically connecting the second power supply electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes is disposed so that distances between the first power supply electrode and the power supply contact electrically connected to the first power supply electrode are substantially equal.
Each of the second plurality of through holes is disposed so that distances between the second through holes and a power supply contact electrically connected to the second power supply electrode are substantially equal. An elongated substrate having electrical insulation;
A heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first conductor electrically connected to one end of the heating resistor on one surface of the substrate;
A second conductor electrically connected to the other end of the heating resistor on one surface of the substrate;
A first power supply electrode facing the first conductor through the substrate on the other surface opposite to the one surface of the substrate;
A second power supply electrode facing the second conductor via the substrate on the other surface of the substrate;
A first plurality of through-holes penetrating the substrate at a plurality of locations in the region of the first conductor and electrically connecting the first power feeding electrode and the first conductor; Multiple through-holes,
A second plurality of through-holes penetrating the substrate at a plurality of locations in the region of the second conductor and electrically connecting the second power feeding electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes is disposed such that distances between the plurality of power supply contacts electrically connected to the first power supply electrode are substantially equal to each other.
Each of the second plurality of through holes is disposed so that distances between the plurality of power supply contacts electrically connected to the second power supply electrode are substantially equal to each other. Heating body. An elongated substrate having electrical insulation;
A first heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first feeding electrode electrically connected to one end of the first heating resistor on one surface of the substrate;
A second feeding electrode not physically in contact with the first heating resistor on one surface of the substrate;
A third feeding electrode electrically connected to the other end of the first heating resistor on one surface of the substrate;
A second heating resistor provided along the longitudinal direction of the substrate on the other surface opposite to the one surface of the substrate and generating heat by energization;
A first conductor facing the first feeding electrode on the other surface of the substrate through the substrate and electrically connected to one end of the second heating resistor;
A second conductor opposed to the second feeding electrode on the other surface of the substrate through the substrate and electrically connected to the other end of the second heating resistor;
A plurality of first through holes penetrating the substrate at a plurality of locations in the region of the first power supply electrode, and electrically connecting the first power supply electrode and the first conductor. Multiple through-holes,
A plurality of second through holes penetrating the substrate at a plurality of locations in the region of the second power supply electrode, and electrically connecting the second power supply electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes is disposed such that distances between the plurality of power supply contacts electrically connected to the first power supply electrode are substantially equal to each other.
Each of the second plurality of through holes is disposed so that distances between the plurality of power supply contacts electrically connected to the second power supply electrode are substantially equal to each other. Heating body. An elongated substrate having electrical insulation;
A heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first conductor electrically connected to one end of the heating resistor on one surface of the substrate;
A second conductor electrically connected to the other end of the heating resistor on one surface of the substrate;
A first power supply electrode facing the first conductor through the substrate on the other surface opposite to the one surface of the substrate;
A second power supply electrode facing the second conductor via the substrate on the other surface of the substrate;
A first plurality of through-holes penetrating the substrate at a plurality of locations in the region of the first conductor and electrically connecting the first power feeding electrode and the first conductor; Multiple through-holes,
A second plurality of through-holes penetrating the substrate at a plurality of locations in the region of the second conductor and electrically connecting the second power feeding electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes has a substantially equal distance from a power supply contact electrically connected to the first power supply electrode, and is on the same side as one end of the heating resistor on the substrate. Are arranged so that the distance between the ends of the
Each of the second plurality of through holes has a substantially equal distance from a power supply contact electrically connected to the second power supply electrode, and is the same as the other end of the heating resistor on the substrate. A heating element, wherein the heating element is disposed so that distances between the side ends are substantially equal. An elongated substrate having electrical insulation;
A first heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first feeding electrode electrically connected to one end of the first heating resistor on one surface of the substrate;
A second feeding electrode not physically in contact with the first heating resistor on one surface of the substrate;
A third feeding electrode electrically connected to the other end of the first heating resistor on one surface of the substrate;
A second heating resistor provided along the longitudinal direction of the substrate on the other surface opposite to the one surface of the substrate and generating heat by energization;
A first conductor facing the first feeding electrode on the other surface of the substrate through the substrate and electrically connected to one end of the second heating resistor;
A second conductor opposed to the second feeding electrode on the other surface of the substrate through the substrate and electrically connected to the other end of the second heating resistor;
A plurality of first through holes penetrating the substrate at a plurality of locations in the region of the first power supply electrode, and electrically connecting the first power supply electrode and the first conductor. Multiple through-holes,
A plurality of second through holes penetrating the substrate at a plurality of locations in the region of the second power supply electrode, and electrically connecting the second power supply electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes has a substantially equal distance from a power supply contact electrically connected to the first power supply electrode, and one end of the second heating resistor on the substrate Are arranged so that the distance between the same and the end on the same side is approximately equal,
Each of the second plurality of through holes has a substantially equal distance from a power supply contact electrically connected to the second power supply electrode, and the other end of the second heating resistor on the substrate. A heating element, wherein the heating element is disposed so that the distance between the first part and the end part on the same side is substantially equal. An elongated substrate having electrical insulation;
A heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first conductor electrically connected to one end of the heating resistor on one surface of the substrate;
A second conductor electrically connected to the other end of the heating resistor on one surface of the substrate;
A first power supply electrode facing the first conductor through the substrate on the other surface opposite to the one surface of the substrate;
A second power supply electrode facing the second conductor via the substrate on the other surface of the substrate;
A first plurality of through-holes penetrating the substrate at a plurality of locations in the region of the first conductor and electrically connecting the first power feeding electrode and the first conductor; Multiple through-holes,
A second plurality of through-holes penetrating the substrate at a plurality of locations in the region of the second conductor and electrically connecting the second power feeding electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through-holes has a substantially equal distance from the center between the plurality of power supply contacts electrically connected to the first power supply electrode, and the heating resistor of the substrate It is arranged so that the distance between one end and the end on the same side is substantially equal,
Each of the second plurality of through-holes has a substantially equal distance between the plurality of power supply contacts electrically connected to the second power supply electrode, and the other end of the heating resistor on the substrate. The heating element is arranged so that the distance between the same and the end on the same side is substantially equal. An elongated substrate having electrical insulation;
A first heating resistor provided on one side of the substrate along the longitudinal direction of the substrate and generating heat by energization;
A first feeding electrode electrically connected to one end of the first heating resistor on one surface of the substrate;
A second feeding electrode not physically in contact with the first heating resistor on one surface of the substrate;
A third feeding electrode electrically connected to the other end of the first heating resistor on one surface of the substrate;
A second heating resistor provided along the longitudinal direction of the substrate on the other surface opposite to the one surface of the substrate and generating heat by energization;
A first conductor facing the first feeding electrode on the other surface of the substrate through the substrate and electrically connected to one end of the second heating resistor;
A second conductor opposed to the second feeding electrode on the other surface of the substrate through the substrate and electrically connected to the other end of the second heating resistor;
A plurality of first through holes penetrating the substrate at a plurality of locations in the region of the first power supply electrode, and electrically connecting the first power supply electrode and the first conductor. Multiple through-holes,
A plurality of second through holes penetrating the substrate at a plurality of locations in the region of the second power supply electrode, and electrically connecting the second power supply electrode and the second conductor. Multiple through-holes,
Have
Each of the first plurality of through holes has a substantially equal distance from the center between the plurality of power supply contacts electrically connected to the first power supply electrode, and the second heat generation in the substrate. The distance between one end of the resistor and the end on the same side is approximately equal,
Each of the second plurality of through holes has a substantially equal distance from the center between the plurality of power supply contacts electrically connected to the second power supply electrode, and the second heat generation in the substrate. A heating element, wherein the distance between the other end of the resistor and the end on the same side is substantially equal. A heating member, a flexible member that moves in contact with the heating member, and a backup member that forms a nip portion with the heating member via the flexible member, and an image is captured at the nip portion. In an image heating apparatus for heating an image on a recording material while nipping and conveying the recording material to be carried,
An image heating apparatus comprising the heating body according to any one of claims 1 to 8 as the heating body.