JP2008299205A - Heater and image heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress temperature rise in a paper non-passing area and to make print speed higher for small size recording material. <P>SOLUTION: In a heater 11 equipped with a plurality of electrodes 11e extending in a direction orthogonal to a recording material conveying direction (direction shown by an arrow) and provided in the recording material conveying direction, and an energizing heating resistance layer 11b extending between the electrodes 11e, at least one electrode out of the plurality of electrodes 11e is divided (constituted of a plurality of electrodes). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heater and an image heating apparatus.

  Conventionally, a so-called heat roller type fixing device has been widely used in an image heating device (hereinafter referred to as a fixing device) provided in an image forming apparatus employing an electrophotographic method, an electrostatic recording method, or the like. A heat roller type fixing device allows a recording material carrying an unfixed toner image to pass through a nip formed by a fixing roller and a pressure roller that are pressed against each other to form a permanent image on the recording material. It is to fix.

  On the other hand, a film heating type fixing device has been put into practical use in which power is not supplied to the fixing device during standby and power consumption is kept as low as possible. A film heating type fixing device has been proposed and put to practical use in Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and the like.

  FIG. 8 is a schematic configuration diagram showing a typical film heating type fixing device.

  In the fixing device shown in FIG. 8, a resinous or metallic high thermal conductive film 53 (flexible sleeve, hereinafter referred to as a fixing film) is provided between the ceramic heater 51 held by the heat insulating holder 52 and the pressure roller 50. ), A fixing nip portion N is formed. Then, a recording material on which an unfixed toner image is formed and supported is introduced into the fixing nip portion N to perform heat fixing.

  As a means for forming a sufficient fixing nip portion N for obtaining a good fixed image, a fixing member including a heater 51 and a fixing film 53 is pressed against a pressure roller 50 by a pressure spring (not shown) or the like. It is pressed against the elasticity of the roller 50. Further, in order to stably form a fixing nip portion N having a substantially uniform width in the longitudinal direction of the fixing member, the length of the heat insulating holder 52 is set via a metal stay 54 formed in an inverted U shape. A substantially uniform pressure is applied in the direction.

  A typical heater 51 used in such a film heating type fixing device is shown in FIG. Such a heater is proposed in Patent Document 5, for example. As shown in FIG. 9, such a heater is obtained by forming an energized heat generating resistor layer 51b on one surface of a highly insulating substrate 51a having a flat plate shape such as alumina or aluminum nitride, and the heat generating resistor layer is a glass film. It is protected by 51c. The fixing film rotates in contact with the protective glass film so as to slide. Alternatively, a glass film having good slidability is formed on the other surface of the ceramic substrate, and the sliding glass film and the fixing film are used so as to slide. Therefore, the heat of the resistance heating element is transmitted to the fixing film through the glass film coated over the entire length of the heater.

Various image forming apparatuses such as printers and copiers using such a film heating type fixing device eliminate the need for preheating during standby and shorten the wait time due to high heating efficiency and rising speed. Thus, it has many advantages over the conventional method. Here, the conventional method is a method in which heat fixing is performed using a heat roller or the like as described above.
JP-A-63-313182 Japanese Patent Laid-Open No. 2-157878 JP-A-4-44075 JP-A-4-204980 JP-A-6-5356 JP-A-6-175519

  However, in recent years, image forming apparatuses such as copiers and printers have various problems such as printing speed, startup speed, energy saving, and compactness. As the speed of each part increases, the fixing temperature rises, and in order to realize a quick start, improvement in the thermal response of the heater and reduction in the heat capacity are attempted.

  As a result, the area where there is a recording material in the fixing nip where paper is relatively removed from the paper when the paper is passed (paper passing area), and the area where there is no recording material and heat is not taken away (non-paper passing area) ) And the temperature difference increases. For this reason, when a relatively small recording material (small size paper) is passed with respect to the longitudinal width of the fixing device, the temperature difference increases in the longitudinal direction of the fixing device.

  This indicates that the margin between the temperature at which the fixing ability of the recording material can be secured and the breakdown temperature of the fixing device is small. Conventionally, in order to reduce this temperature difference, compared to passing a relatively large recording material (full-size paper), when passing a relatively small recording material, the printing speed is lowered to reduce the heat. Often earns relaxation time. Further, in that case, useless heat is generated, so that the internal temperature of the image forming apparatus rises, causing thermal damage to each part. As a result, it is difficult to reduce the size.

  As a prior art for this problem, a method has been proposed in which current is supplied in the direction of introduction of the material to be heated, and the temperature rise of the non-sheet passing portion is suppressed by the PTC (Positive Temperature Coefficient) characteristics of the heating member.

  However, in this case, a heat generating material having a PTC characteristic that can supply a fixing securing temperature and that does not reach the breakdown temperature of the fixing device is required, and has a strong PTC characteristic in a specific temperature range. In order to meet the demand, the development of special materials is required. In general, a material having a strong PTC characteristic has a low resistance value, which causes problems such as heat generation unevenness caused by a resistance difference in the longitudinal direction, and has not been put into practical use. In addition, since the non-sheet-passing section is above the temperature that can secure the fixability, it lacks control robustness and supplies the optimal heat according to the media when large-size paper is flowed after small-size paper. I can't.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to suppress a temperature rise in a non-sheet-passing area and increase a printing speed for a small-size recording material.

In order to achieve the above object, the present invention provides:
Used in an image heating apparatus that heats the recording material while nipping and conveying the recording material at a nip formed by a heater that contacts the movable flexible sleeve and a driving member that drives the flexible sleeve. Heater,
A plurality of conductor portions extending in a direction orthogonal to the recording material conveyance direction when the recording material is conveyed at the nip portion of the image heating apparatus, and a plurality of conductor portions provided in the recording material conveyance direction;
A resistor extending in the orthogonal direction between the plurality of conductor portions;
With
At least one conductor portion among the plurality of conductor portions is configured by arranging a plurality of conductor members in the orthogonal direction.

  According to the present invention, it is possible to suppress the temperature rise in the non-sheet passing region and increase the printing speed for a small size recording material.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.

(Image forming device)
FIG. 1 is a schematic cross-sectional view of the image forming apparatus according to the first embodiment.

  In FIG. 1, a photosensitive drum 1 as an image carrier is configured by forming a photosensitive material such as OPC, amorphous Se, or amorphous Si on a cylindrical substrate such as aluminum or nickel.

  The photosensitive drum 1 is rotationally driven in the direction of the arrow shown in FIG. 1, and first, its surface is uniformly charged by a charging roller 2 as a charging means. Next, the laser scanner 3 performs scanning exposure with a laser beam L that is ON / OFF controlled in accordance with image information, thereby forming an electrostatic latent image. This electrostatic latent image is developed and visualized by the developing device 4. As a development method, a jumping development method, a two-component development method, a FEED development method (contact development method using a one-component insulating toner), or the like is used, and image exposure and reversal development are often used in combination.

  The visualized toner image is transferred from the photosensitive drum 1 onto the recording material P conveyed at a predetermined timing by a transfer roller 5 as a transfer unit. Here, the sensor 8 detects the leading edge of the recording material and matches the timing so that the image forming position of the toner image on the photosensitive drum 1 matches the writing position of the leading edge of the recording material.

  The recording material P conveyed at a predetermined timing is nipped and conveyed between the photosensitive drum 1 and the transfer roller 5 with a constant pressure. The recording material P to which the toner image has been transferred is conveyed to a heat fixing device 6 as an image heating device and fixed as a permanent image.

  On the other hand, the residual toner remaining on the photosensitive drum 1 is removed from the surface of the photosensitive drum 1 by the cleaning device 7. Reference numeral 9 denotes a discharge sensor provided in the heat fixing device 6, which is a sensor for detecting when a recording material causes a paper jam (jam) between the top sensor 8 and the discharge sensor. is there.

(Heat fixing device)
2A and 2B are schematic configuration schematic diagrams of the heat fixing device 6. FIG. 2A is a cross-sectional view, FIG. 2B is a heater cross-sectional view, and FIG. 2C is a perspective view.

  This heat fixing device 6 is basically a film heating type heat fixing device comprising a fixing assembly (fixing member) 10 that forms a fixing nip portion N by being pressed against each other, and a pressure roller 20 as a driving member. .

  As shown in FIGS. 2A and 2C, the fixing assembly 10 mainly includes a fixing film 13 as a flexible sleeve, a heater 11 as a heater, a heat insulating holder 12 that holds the heater 11, and The metal stay 14 is configured. Here, the metal stay 14 receives pressure from the pressure spring 15 and presses the heat insulating holder 12 against the pressure roller 20.

(Fixing film)
The fixing film 13 is a heat-resistant film having a total thickness of 200 μm or less in order to enable quick start. Heat resistant resin such as polyimide, polyamideimide, PEEK (polyetheretherketone), SUS (stainless steel) with high heat resistance and high thermal conductivity, pure metal such as Al, Ni, Cu, Zn, or alloy as base layer Is formed.

  In the case of a resin base layer, in order to improve thermal conductivity, high thermal conductive powder such as BN, alumina, Al, etc. may be mixed. Further, the fixing film 13 having a sufficient strength and excellent durability for constituting a long-life heat fixing apparatus needs to have a total thickness of 20 μm or more. Therefore, the total thickness of the fixing film 13 is optimally 20 μm or more and 200 μm or less.

  Furthermore, in order to prevent offset and ensure separation of the recording material, the surface layer is mixed with a heat-resistant resin having a good releasability such as PTFE, PFA, FEP, ETFE, CTFE, PVDF, etc., and a silicone resin. And a release layer (release layer) is formed. In this embodiment, the surface layer is made of a material containing at least PTFE and PFA.

Here, PTFE is polytetrafluoroethylene, PFA is a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, and FEP is a tetrafluoroethylene hexafluoropropylene copolymer. ETFE is an ethylene tetrafluoroethylene copolymer, CTFE is polychlorotrifluoroethylene, and PVDF is polyvinylidene fluoride.

  As a coating method, the outer surface of the fixing film 13 may be etched and then the release layer may be dipped or applied by powder spraying or the like. Alternatively, a method of covering the surface of the fixing film 13 with a resin formed in a tube shape may be used. Alternatively, after the outer surface of the fixing film 13 is blasted, a primer layer that is an adhesive may be applied to cover the release layer.

(Pressure roller)
The pressure roller 20 is made of an elastic solid rubber layer, an elastic sponge rubber layer, an elastic foam rubber layer or the like on the outside of a metal core 21 made of SUS, SUM (sulfur and sulfur composite free-cutting steel), Al or the like. An elastic roller made of the layer 22. Here, the elastic solid rubber layer is formed of heat-resistant rubber such as silicone rubber or fluorine rubber. The elastic sponge rubber layer is formed by foaming silicone rubber in order to have a more heat insulating effect. The elastic foam rubber layer is a layer in which a hollow filler (such as a microballoon) is dispersed in a silicone rubber layer, and a gas portion is provided in the cured product to enhance the heat insulation effect. A release layer such as perfluoroalkoxy resin (PFA) or polytetrafluoroethylene resin (PTFE) may be formed thereon.

(Heating heater)
As shown in FIG. 2B, the heater 11 heats the fixing nip N by contacting the inner surface of the fixing film 13.

In the heater 11, an insulating ceramic substrate 11a such as alumina or aluminum nitride is provided in a plate shape with a low heat capacity. Then, on the surface of the insulating ceramic substrate 11a, an energization heat generating resistance layer 11b as a resistor such as Ag / Pd (silver palladium), RuO ₂ (ruthenium oxide), Ta ₂ N (tantalum nitride) is provided along the longitudinal direction. Is formed by screen printing or the like. The energization heat generating resistance layer 11b is formed to have a thickness of about 10 μm and a width of about 1 to 5 mm. Here, the longitudinal direction is a direction orthogonal to the recording material conveyance direction in which the recording material is conveyed, is the axial direction of the pressure roller 20, and is the longitudinal direction of the fixing nip portion N.

  On the surface where the heater 11 is in contact with the fixing film 13, a protective layer 11 c is provided to protect the energized heating resistance layer within a range that does not impair the thermal efficiency. The thickness of the protective layer is preferably thin enough to improve the surface properties, and glass or a fluororesin coat is applied. Details regarding the configuration of the heater 11 according to the present embodiment will be described later.

  The heat insulating holder 12 that holds the heater 11 is formed of a heat resistant resin such as liquid crystal polymer, phenol resin, PPS, or PEEK. The lower the thermal conductivity, the better the heat conduction to the pressure roller 20, so a filler such as a glass balloon or a silica balloon may be included in the resin layer. It also serves to guide the rotation of the fixing film 13.

  Reference numeral 14 denotes a metal stay that contacts the heat insulating holder 12 and suppresses bending and twisting of the entire fixing assembly.

(Method for driving and controlling the heat fixing device)
The fixing assembly 10 is pressed against the elasticity of the pressure roller 20 by the following configuration to form a fixing nip portion N. That is, as shown in FIG. 2C, the metal stay 14 has both ends in the longitudinal direction protruding from the heat insulating holder 12, and the spring receiving portions 14a at both ends of the stay are moved by the coil spring 15 via the spring receiving members. Pressurized. The load is transmitted uniformly over the longitudinal direction of the heat insulating holder 12 via the stay foot 14b.

  At the fixing nip portion N, the fixing film 13 is bent by being sandwiched between the heater 11 and the pressure roller 20 by the applied pressure, and is in close contact with the heating surface of the heater 11.

  The pressure roller 20 obtains a driving force that rotates in the direction of the arrow in FIG. 2A by a driving gear (not shown) provided at the end of the cored bar 21. The driving force is transmitted from a motor (not shown) in accordance with a command from a CPU (not shown) that controls the control means.

  As the pressure roller is driven to rotate, the fixing film 13 is driven and rotated (moved) by a frictional force with the pressure roller 20. At this time, the fixing film 13 slides with respect to the heater 11. Between the fixing film 13 and the heater 11, by interposing a lubricant such as fluorine-based or silicone-based heat resistant grease, the frictional resistance is kept low, and the fixing film 13 can be rotated smoothly (movable). It becomes.

  The temperature control of the heater 11 is appropriately controlled by determining the duty ratio, wave number, etc. of the voltage applied by the CPU to the energization heating resistor layer according to a signal from a temperature detection element such as a thermistor (not shown) provided on the back surface of the ceramic substrate. Thus, the temperature in the fixing nip portion is maintained at a desired fixing set temperature. Details regarding the control of the heater 11 according to the present embodiment will be described later.

  The recording material P holding the unfixed toner image is appropriately supplied by a supply unit (not shown) at a predetermined timing, and is nipped and conveyed by the fixing nip portion N to be heated and fixed. The recording material P discharged from the fixing nip N is guided by a discharge guide (not shown) and discharged.

(About the features of the heater)
Below, the heater which is the characteristic structure of a present Example is demonstrated.

  FIG. 3 is a diagram illustrating a schematic configuration of the heater 11 according to the present embodiment. FIG. 4 is a diagram illustrating a schematic configuration of a conventional feeding direction heating heater.

As shown in FIG. 4, the conventional feeding heater in the conveyance direction extends over the entire longitudinal direction of the heating element (the direction perpendicular to the recording material conveyance direction) upstream and downstream of the recording material conveyance direction (arrow direction shown in the figure). An electrode is formed.

  On the other hand, in this embodiment, as shown in FIG. 3, at least one of the electrodes as a plurality of conductors provided upstream and downstream in the recording material conveyance direction (arrow direction shown in the figure) is divided. It is characterized by. In this embodiment, dividing an electrode means that the one electrode (a conductor portion extending in the longitudinal direction, a region where the electrode is disposed) is an electrode as a plurality of conductor members (an electrode having a small length in the longitudinal direction). ).

  With this configuration, it is possible to generate heat by selectively feeding a plurality of divided electrodes according to the type of recording material to be passed. The number of divided electrodes and the divided pattern are arbitrary, but for convenience of explanation, the number of divided portions is 3, and the length in the longitudinal direction of the central electrode is a length corresponding to a small-sized recording material having a small width such as an envelope. To do. That is, the center electrode is included in a passing region through which the recording material conveyed at the fixing nip N passes, and the longitudinal end thereof substantially coincides with the longitudinal end of the recording material. Is provided.

  When passing a small-size recording material, a voltage is applied only to the central electrode to generate heat locally, thereby achieving the same printing speed as a full-size recording material. In a full-size recording material, a voltage is applied to all the electrodes, and printing is performed under the same control as in the prior art.

  As a result, heat can be selectively supplied according to the size of the recording material without depending on the PTC characteristics, and an efficient supply of heat with reduced temperature rise in the non-sheet passing portion can be achieved. The printing speed of the recording material can be increased. Here, in the apparatus of this embodiment, the process speed is 150 mm / sec, and a full-size paper can be printed at a speed of 22 ppm (page per minute).

  FIG. 5 is a diagram for explaining a specific example according to the present technique, and is a diagram illustrating a relationship between the electrode division pattern and the recording material size.

  The length of the heating element 11b is 218 mm, which is slightly wider than the LTR width so that the LTR size (width of about 216 mm), which is the maximum lateral width of the apparatus, can be fixed. The center electrode 11e is an electrode for accommodating a narrow recording material such as an envelope, and is 116 mm slightly wider than the commonly used COM10 envelope width (width of about 105 mm) and DL envelope width (width of about 114 mm). It is as.

  In this apparatus, a comparison was made between a case where a voltage was applied to the center electrode, a conventional energizing heater in the conveyance direction using a conventional PTC characteristic, and a longitudinal energizing heater which is currently generally used. Ten COM10 envelopes were passed at a speed of 22 ppm in an environment of room temperature 23 ° C. and humidity 50%, respectively, and temperature control was performed at 180 ° C. A felt formed of heat-resistant fiber was brought into contact with the pressure roller, and a temperature increase at the end portion was measured by arranging a thermocouple between the pressure roller and the felt. The measurement position is set to a position where the end temperature rise reaches a peak. The measurement results are shown in Table 1.

  Conventional longitudinal energization heaters may damage the pressure roller at 268 ° C, which may damage the pressure roller, and it is necessary to reduce throughput (productivity). However, this method can selectively supply heat. You can see that

  In addition, when a narrow COM10 envelope and a wide LTR size recording material are alternately fed, a hot offset due to edge temperature rise may occur in a longitudinal energizing heater or a PTC characteristic conveying direction energizing heater. Concerned.

  On the other hand, in this method, when the LTR size recording material is passed, the entire longitudinal direction can be heated, and when the COM10 envelope is passed, only the central portion can be heated. Optimal heat can be supplied for each recording material to be recorded. Accordingly, it is possible to obtain a high-quality image without causing image defects such as hot offset even in alternate paper feeding.

  As described above, according to the present embodiment, by using the electrode divided into a plurality in the longitudinal direction, the energization region in the longitudinal direction can be regulated, and the paper passing region in the longitudinal direction is selectively heated. It becomes possible to do. That is, it is possible to partially generate heat in the paper passing area in the longitudinal direction without using a material having special PTC characteristics, and it is possible to suppress the temperature rise in the non-paper passing part.

  As a result, even when a small-size recording material is passed, the print speed can be increased to the same level as the full-size recording material.

  Accordingly, it is possible to increase the printing speed in a recording material having a size smaller than the full size. Furthermore, since generation of useless heat can be suppressed, energy saving and downsizing can be achieved.

  The second embodiment of the present invention will be described below. In the present embodiment, the different components from the first embodiment will be described, and the description of the same components as those in the first embodiment will be omitted.

  This embodiment is characterized in that energization control can be performed on each electrode by providing power supply means for supplying power to each of the divided electrodes independently. As a result, it is possible to control the temperature distribution in the longitudinal direction of the fixing nip portion by performing on / off control or the like for each electrode.

In the so-called medium size recording material, which is wider than the small size recording material and smaller than the full size recording material, the power supply is suppressed on both sides where the temperature rises rapidly, and the current control different from the central part is performed. Do. As a result, it is possible to perform a control that balances the fixability and the temperature rise suppression in the non-sheet passing portion. As a result, even a medium-sized recording material can be speeded up.

  A specific example of this method is shown below.

  As in the first embodiment, the electrode is divided into three sections as shown in FIG. 5, with the length of the central portion in the longitudinal direction being 116 mm.

  When passing a small-sized recording material, the central electrode is fully energized and the electrodes on both sides are not used. When a large recording material such as LTR size is passed, full energization is performed from all three electrodes.

  In the case of a recording material of medium size, for example, B5 size, the width is about 182 mm, which is wider than the electrode width at the center and shorter than the heating element length. In such a case, full energization is performed at the center electrode, while the wave number control is performed at the electrodes on both sides to limit the input power as compared with the center electrode. In this example, when the input power to the electrodes on both sides was set to 75%, the temperature rise at the end could be reduced by 20%. As a result, it was possible to achieve a higher speed than when a conventional longitudinally energized heater was used, and it was possible to increase the throughput from 12 ppm to 15 ppm. The experimental results are shown in Table 2.

  As described above, according to the present embodiment, the power supplied to the plurality of divided electrodes can be controlled, and the temperature rise suppression of the non-sheet passing portion and the sheet passing portion are controlled according to the size of the recording material. Robust temperature control that achieves both fixing properties is possible.

  Example 3 of the present invention will be described below. In the present embodiment, different components from those of the first and second embodiments will be described, and the description of the same components as those of the first and second embodiments will be omitted.

  6A and 6B are diagrams showing a schematic configuration of the heater 11 according to the present embodiment, in which FIG. 6A is a diagram showing a heater surface, and FIG. 6B is a diagram showing a heater back surface.

  The number of divisions and division patterns of electrodes are arbitrary, but for convenience of explanation here, division is performed only on one side of the recording material conveyance direction on one side, the division number is 3, and the length in the longitudinal direction of the central electrode is an envelope or the like The length corresponds to a small-sized recording material with a narrow width.

In this embodiment, as shown in FIG. 6, a through hole 11f is provided in the heater substrate 11a, and a conductor is formed also in the through hole 11f, thereby providing a conduction path that connects the front surface to the back surface of the heater substrate 11a. It is characterized by providing. In the present embodiment, a conduction path is provided for the two electrodes at both ends through the back surface and then to the right side position shown in FIG. 6A on the surface of the heater substrate 11a.

  With this configuration, as shown in FIG. 6, the circuit can be simply arranged, and the connector can be arranged only on one side of the heater in the longitudinal direction. In addition, a conductive path may be arranged on the substrate without providing the through hole 11 and tied to the electrode.

  Also in this embodiment, the throughput when a small-size recording material is passed can be increased, and the same effects as those of Embodiments 1 and 2 described above can be obtained.

  The fourth embodiment of the present invention will be described below. In the present embodiment, different components from those of the first to third embodiments will be described, and the description of the same components as those of the first to third embodiments will be omitted.

  FIG. 7 is a diagram illustrating a schematic configuration of the heater 11 according to the present embodiment, where (a) is a diagram illustrating the heater surface, and (b) is a diagram illustrating the heater back surface.

  In the present embodiment, by providing the same through hole 11f as in the third embodiment, an electrode can be directly taken from the back surface of the heater substrate 11a. As a result, even when a large number of electrode divisions are performed, the connector can be appropriately arranged, so that the problem in arranging the connector can be solved.

  Further, in this embodiment, as shown in FIG. 7, the electrodes are divided in accordance with the width in the longitudinal direction of the COM10 envelope and the B5 size recording material.

  As a result, power can be supplied only to the electrodes that match the size (width) of the recording material based on the size of the recording material. Can be supplied.

  Accordingly, both the COM10 envelope and the B5 size recording material can pass through with a throughput of 22 ppm. That is, also in the present embodiment, the same effect as in the first and second embodiments can be obtained.

1 is a schematic sectional view of an image forming apparatus according to Embodiment 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the heat-fixing apparatus of Example 1, (a) is sectional drawing, (b) is heater sectional drawing, (c) is a perspective view. 1 is a diagram illustrating a schematic configuration of a heater of Example 1. FIG. It is a figure which shows schematic structure of the conventional conveyance direction electric power supply heating heater. FIG. 5 is a diagram for describing a specific example in Example 1, and is a diagram illustrating a relationship between an electrode division pattern and a recording material size. It is a figure which shows schematic structure of the heater of Example 3, (a) is a figure which shows a heater surface, (b) is a figure which shows a heater back surface. It is a figure which shows schematic structure of the heater of Example 4, (a) is a figure which shows a heater surface, (b) is a figure which shows a heater back surface. It is a schematic sectional drawing showing the fixing apparatus of the film heating system of a prior art example. It is a schematic sectional drawing showing the heater of the fixing device of the film heating system of a prior art example.

Explanation of symbols

6 Heating Fixing Device 10 Fixing Assembly 11 Heating Heater 11a Heater Substrate 11b Current Heating Resistance Layer 11c Protective Glass 11d Sliding Layer 11e Electrode 11f Through Hole 11g Conductor 12 Heat Insulating Holder 13 Fixing Film 14 Metal Stay 15 Pressure Spring 20 Pressure Roller 21 Core 22 Elastic layer N Fixing nip P Recording material

Claims (5)

Used in an image heating apparatus that heats the recording material while nipping and conveying the recording material at a nip formed by a heater that contacts the movable flexible sleeve and a driving member that drives the flexible sleeve. Heater,
A plurality of conductor portions extending in a direction orthogonal to the recording material conveyance direction when the recording material is conveyed at the nip portion of the image heating apparatus, and a plurality of conductor portions provided in the recording material conveyance direction;
A resistor extending in the orthogonal direction between the plurality of conductor portions;
With
At least one conductor portion among the plurality of conductor portions is configured by arranging a plurality of conductor members in the orthogonal direction.   At least one conductor member among the plurality of conductor members is included in a passing region through which the recording material conveyed at the nip portion of the image heating apparatus passes, and an end portion in the orthogonal direction is the orthogonal member of the recording material. The heater according to claim 1, wherein the heater is provided so as to coincide with an end portion in the direction. The conductor portion and the resistor are provided on the surface of the substrate,
The heater according to claim 1 or 2, wherein a conduction path connected to at least one of the plurality of conductor portions is provided from the front surface to the back surface of the substrate. The heater according to any one of claims 1 to 3,
A flexible sleeve sliding with the heater;
A drive member that forms a nip portion with the heater via the flexible sleeve and drives the flexible sleeve;
With
An image heating apparatus that heats the recording material while nipping and conveying the recording material at the nip portion.   The image heating apparatus according to claim 4, further comprising a power supply unit that supplies power independently to each of the plurality of conductor members.