JP2016109928A - Fixing device, image formation apparatus with the same, and method of manufacturing heating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device that can secure strength of a heating constitution part for heating a fixing belt even when a heating member is made thin so as to reduce thermal capacity of the heating member, and thereby enables the heating member to be pressed strongly against an inner peripheral surface of the fixing belt and also can reduce heating loss to improve heating efficiency, an image formation apparatus with the same, and a method of manufacturing the heating member.SOLUTION: There is provided a fixing device which comprises a fixing member, a heating member, an endless fixing belt, and a pressure applying member, and fixes an unfixed image on a recording material, passing through a fixing nip part, on the recording material. The heating member has a heating part in a curved shape curved convexly toward the fixing belt. A heating constitution part for heating the fixing belt has the heating member and a fixing member which fixes the heating member by bridging between both peripheral sides thereof.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multi function printer (MFP), in particular, a fixing device of a sheet heating belt fixing method and an image forming apparatus including the same. In addition, the present invention relates to a method for manufacturing a heating member.

  A fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile machine, or an MFP is usually a fixing member (specifically, a fixing roller) and a pressure member (specifically, a pressure roller) that are heated by a heat source. Thus, the unfixed image is fixed to a recording material such as recording paper on which an unfixed image (specifically, an unfixed toner image) is formed.

  As such a fixing device, a heat roller fixing type fixing device is frequently used. A heat roller fixing type fixing device includes a pair of rollers (specifically, a fixing roller and a pressure roller) that are in pressure contact with each other, and a heat source such as a halogen heater disposed inside or both of the roller pair. And. Then, the heat roller fixing type fixing device heats the roller pair to a predetermined temperature (fixing temperature) with a heat source, and then supplies the recording material on which the unfixed image is formed to the fixing nip portion which is the pressure contact portion of the roller pair. Then, by passing through the fixing nip portion, the unfixed image is fixed on the recording material by heat and pressure in the fixing nip portion.

  For example, in a fixing device provided in a color image forming apparatus, an elastic roller provided with an elastic layer made of an elastic member such as silicon rubber as a surface layer is generally used as a fixing roller. By using an elastic roller as the fixing roller, the surface of the fixing roller is elastically deformed corresponding to the unevenness of the unfixed toner image and comes into contact so as to cover the image surface of the toner image. For this reason, it is possible to satisfactorily heat and fix an unfixed toner image in color image formation with a larger amount of toner than in monochrome image formation. In addition, due to the strain relief effect of the elastic layer at the fixing nip, it is possible to improve the releasability for color toners that are more easily offset than monochrome toners. Further, since the nip shape of the fixing nip portion is convex (so-called reverse nip shape) on the toner image side (fixing roller side), it is possible to improve the peeling performance of the recording material, and to remove peeling means such as a peeling claw. Even if not used, the recording material can be surely peeled off (self-stripping), and image defects caused by the peeling means can be eliminated.

  Here, in a fixing device provided in such an image forming apparatus (particularly a color image forming apparatus), it is necessary to widen the nip width of the fixing nip portion in order to cope with an increase in the image forming speed (process speed). is there. Examples of the method for widening the nip width include a method for increasing the elastic layer of the fixing roller and a method for increasing the roller diameter of the fixing roller.

  However, in the fixing roller having a thick elastic layer, the heat conductivity of the elastic layer is lower than that of a member having excellent heat conductivity such as a metal. When the heat source is provided, when the process speed is increased, the heat supply from the heat source to the elastic layer in the fixing roller becomes insufficient, and the surface temperature of the fixing roller does not follow. On the other hand, with a fixing roller having a larger roller diameter, the curvature is reduced and the nip width of the fixing nip portion can be increased, but the heat capacity increases as the roller diameter increases, and the warm-up time (the surface of the fixing roller) The time required for the temperature to reach a predetermined temperature) becomes longer, and power consumption increases.

  In order to eliminate such inconveniences, various configurations have recently been proposed as fixing devices included in image forming apparatuses.

  For example, Patent Document 1 discloses a fixing device of an external belt heating fixing system that uses an external heating belt to heat a fixing roller from the outside. In this external belt heat fixing type fixing device, the fixing roller can be efficiently heated from the outside, and the warm-up time can be shortened.

  In Patent Document 2, a heating roller heated by a heat source such as a halogen lamp is used as a heating unit, the heating roller is disposed outside the fixing roller, and a fixing belt is placed between the fixing roller and the heating roller. A belt fixing type fixing device (belt fixing device) having a configuration in which a fixing roller and a pressure roller are brought into pressure contact with each other via a fixing belt is disclosed. In this belt fixing device, since the fixing belt having a smaller heat capacity than the fixing roller is heated, the warm-up time can be further shortened.

  In both the external belt heat fixing method and the belt fixing method described above, since it is not necessary to incorporate a heat source such as a halogen lamp in the fixing roller, the fixing roller is made of a low-hardness elasticity made of an elastic member such as sponge rubber. A thick layer can be provided, and a wide nip width can be secured.

  In Patent Document 3, Patent Document 4, and Patent Document 5, in the belt fixing apparatus, a heating member (specifically, a planar heater) having a curved shape that is convexly curved toward the fixing belt is used as a heating unit. A sheet heating belt fixing type fixing device (sheet heating belt fixing device) is disclosed. In this sheet heating belt fixing device, since the heating layer is formed on the heating member as a heat source, the heat capacity of the heating unit is smaller than that of the conventional heating roller, and the heating member as a heating unit (specifically, The sheet heater directly generates heat. As a result, compared to a belt-fixing type fixing device that indirectly heats the heating roller using a heat source such as a halogen lamp, the thermal responsiveness is improved, further shortening the warm-up time and further saving energy. Can be achieved.

JP 2007-212896 (published on August 23, 2007) Japanese Patent Laid-Open No. 10-30796 (published November 17, 1998) JP 2002-333788 A (published on November 22, 2002) JP 2003-287969 A (published October 10, 2003) JP 2006-293051 A (published October 26, 2006)

  However, in the conventional sheet heating belt fixing device, since the heating component for heating the fixing belt is configured only by the heating member, for example, if the heating member is thinned to reduce the heat capacity of the heating member. , The strength of the heating component constituting the heating member is low, and therefore the heating member cannot be strongly pressed against the inner peripheral surface of the fixing belt, so that a minute gap is easily formed between the heating member and the fixing belt, If it does so, a heating loss will become large and heating efficiency will become low.

  Therefore, the present invention can secure the strength of the heating component for heating the fixing belt even if the heating member is thinned to reduce the heat capacity of the heating member, thereby fixing the heating member. To provide a fixing device that can be strongly pressed against the inner peripheral surface of a belt, and thus can improve heating efficiency by reducing heating loss, an image forming apparatus including the fixing device, and a heating member manufacturing method. Objective.

  In order to solve the above-described problems, the present invention provides the following fixing device, image forming apparatus, and heating member manufacturing method.

(1) Fixing device Fixing member, heating member, endless fixing belt stretched by the fixing member and the heating member and heated by the heating member while moving to one side in the circumferential direction A pressure member that is in pressure contact with the fixing member via the fixing belt and forms a fixing nip portion together with the fixing belt at a pressure contact portion with the fixing member via the fixing belt. A fixing device for fixing an unfixed image on a recording material passing through a recording material to the recording material, wherein the heating member has a curved heating portion that is convexly curved toward the fixing belt, and the fixing belt The heating component for heating the fixing member includes the heating member and a fixing member that bridges and fixes both sides of the heating member in the circumferential direction.

(2) Image forming apparatus An image forming apparatus comprising the fixing device according to the present invention.

(3) Heating member manufacturing method A heating member manufacturing method for manufacturing the heating member in the fixing device according to the present invention, wherein the heating step is laminated to form a flat heating member. And a second step of processing the flat plate-like heating member formed by laminating the heat generating layer in the first step into a kamaboko-shaped heating member by a predetermined bending process. Production method.

  In the present invention, the fixing member may be exemplified by a heat resistant resin or ceramic.

  In the present invention, the heating member and the fixing member extend in a direction along a surface of the fixing belt perpendicular to the circumferential direction, and the heating member is entirely or substantially entirely in a heating region of the heating unit. The aspect provided with the heat generating layer formed automatically can be illustrated.

  In the present invention, a pair of power supply electrodes for supplying power to the heat generating layer can be exemplified as a structure configured to supply the heat generating layer in the circumferential direction.

  In the present invention, a pair of power supply electrodes for supplying power to the heat generating layer can be exemplified as being provided at or near both ends of the fixing member in the short direction of the fixing member.

  In the present invention, among the pair of power supply electrodes that energize the heat generating layer in the circumferential direction, at least one power supply electrode is provided in a plurality electrically independent from each other in the longitudinal direction of the fixing member. Can be illustrated.

  In the present invention, it is possible to exemplify a mode in which the heating member is provided with energization guide portions that respectively direct the energization directions of the plurality of power supply electrodes provided independently of each other in the circumferential direction.

  In the present invention, the power supply pattern that electrically connects the power supply side and a plurality of the power supply electrodes that are electrically independent from each other is provided on both sides in the thickness direction of the fixing member. It can be illustrated.

  In the present invention, a plurality of the feeding electrodes that are electrically provided independently of each other can be exemplified by a mode in which switching elements are individually electrically connected.

  In the present invention, the switching element can be exemplified by a silicon carbide (SiC) semiconductor.

  In the present invention, it is possible to exemplify an aspect in which the heating component is disposed so as to be close to the inlet side of the fixing nip with respect to the conveyance direction of the recording material.

  According to the present invention, even if the heating member is made thin in order to reduce the heat capacity of the heating member, the strength of the heating component for heating the fixing belt can be ensured. It is possible to provide a fixing device that can strongly press against the inner peripheral surface of the image forming apparatus, and thus can improve heating efficiency by reducing heating loss, an image forming apparatus including the fixing device, and a method for manufacturing a heating member. .

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus including a fixing device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a schematic configuration of a main part of the fixing device according to the first embodiment together with a control configuration of a power source electrically connected to a heating unit. FIG. 2 is a cross-sectional view illustrating a schematic configuration of a heating unit in the fixing device according to the first embodiment together with a power source electrically connected to the heating unit. FIG. 2 is a schematic configuration diagram illustrating a heating member constituting a heating unit in the fixing device according to the first embodiment, where (a) is a front view of the heating member viewed from the front side, and (b) is a heating member. It is the side view which looked at from the inside. FIG. 3 is a schematic configuration diagram illustrating a fixing member that constitutes a heating unit in the fixing device according to the first embodiment, and is a side view of the fixing member viewed from the heating member side. FIG. 3 is a schematic configuration diagram illustrating a fixing member that constitutes a heating unit in the fixing device according to the first embodiment, and is a side view of the fixing member viewed from the side opposite to the heating member side. FIG. 6 is a schematic configuration diagram illustrating a fixing member that constitutes a heating unit in the fixing device according to the first embodiment, and is a cross-sectional view taken along line AA illustrated in FIG. 5. FIG. 3 is a schematic diagram schematically showing a heat generation area of a heating member in the fixing device according to the first embodiment. It is explanatory drawing for demonstrating the manufacturing method of the heating member in a fixing device, Comprising: (a) is a figure which shows a 1st process, (b) is a figure which shows a 2nd process. In the fixing device according to the first embodiment, it is an explanatory diagram for explaining the difference in temperature uniformity depending on the direction of energization to the heat generating layer, wherein (a) is a pair of power supply electrodes for energizing the heat generating layer in the longitudinal direction. FIG. 6B is a graph showing a temperature distribution in the longitudinal direction of the heat generating layer when the heat generating layer is energized in the longitudinal direction by a pair of power supply electrodes. In the fixing device according to the first embodiment, it is an explanatory diagram for explaining a difference in temperature uniformity depending on a direction of energization to the heat generation layer, wherein (a) is a pair of power supply electrodes for energizing the heat generation layer in the circumferential direction. FIG. 6B is a graph showing a temperature distribution in the longitudinal direction of the heat generating layer when the heat generating layer is energized in the circumferential direction by a pair of power supply electrodes. It is a schematic block diagram which shows the heating member which comprises the heating unit in the fixing device which concerns on 2nd Embodiment, Comprising: (a) is the front view which looked at the heating member from the front side, (b) is a heating member. It is the side view which looked at from the inside. FIG. 9 is a schematic configuration diagram illustrating a fixing member that constitutes a heating unit in a fixing device according to a second embodiment, and is a side view of the fixing member viewed from the heating member side. FIG. 9 is a schematic configuration diagram illustrating a fixing member that constitutes a heating unit in a fixing device according to a second embodiment, and is a side view of the fixing member viewed from the side opposite to the heating member side. It is a schematic block diagram which shows the fixing member which comprises the heating unit in the fixing device which concerns on 2nd Embodiment, Comprising: (a) is sectional drawing along the BB line shown in FIG. 13, (b). FIG. 14 is a cross-sectional view taken along line CC shown in FIG. 13. FIG. 10 is a schematic diagram schematically showing a heat generation area of a heating member in a fixing device according to a second embodiment. FIG. 10 is a diagram illustrating a schematic configuration of a fixing member that constitutes a heating unit in a fixing device according to a third embodiment, and is a side view of the fixing member viewed from the heating member side. FIG. 10 is a diagram illustrating a schematic configuration of a fixing member that constitutes a heating unit in a fixing device according to a third embodiment, and is a side view of the fixing member viewed from the side opposite to the heating member side. FIG. 18 is a diagram showing a schematic configuration of a fixing member constituting a heating unit in a fixing device according to a third embodiment, and is a cross-sectional view taken along the line DD shown in FIG. 17. FIG. 10 is a schematic diagram schematically showing a heat generation area of a heating member in a fixing device according to a third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Image forming apparatus]
First, the configuration of the image forming apparatus 100 according to the embodiment of the present invention will be described below with reference to FIG.

  FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 100 including a fixing device 15 according to an embodiment of the present invention.

  As shown in FIG. 1, an image forming apparatus 100 according to the present embodiment is a so-called tandem type color image forming apparatus in which a plurality of image carriers are arranged in a predetermined direction. In this example, the image forming apparatus 100 functions as a printer unit of an intermediate transfer type color multifunction peripheral capable of forming a full-color image. In this embodiment, the fixing device 15 is applied to a tandem color image forming apparatus, but may be applied to other color image forming apparatuses. The fixing device 15 is applied to a color image forming apparatus, but may be applied to a monochrome image forming apparatus.

  The image forming apparatus 100 is an electrophotographic image forming apparatus, and a plurality of (in this example, four sets) image forming units pa, pb, pc, pd, an exposure unit 10, and a plurality (in this example, four) primary. Transfer unit 13a, 13b, 13c, 13d, intermediate transfer belt 11, waste toner box unit 12, secondary transfer unit 14, fixing device 15 (fixing unit in this example), recording material containing recording material P such as recording paper A housing portion (specifically, an internal paper feed unit 16 and a manual paper feed unit 17) is provided.

  The image forming units pa, pb, pc, and pd include charging devices 103a, 103b, 103c, and 103d, developing units 102a, 102b, 102c, and 102d, and cleaning units 104a, 104b, 104c, and 104d, respectively, as image carriers. Around a plurality of (in this example, four) photosensitive members 101a, 101b, 101c, and 101d (specifically, photosensitive drums) that act, charging devices 103a, 103b, 103c, and 103d, and developing units 102a and 102b, respectively. , 102c, 102d and cleaning units 104a, 104b, 104c, 104d are arranged in this order.

  Each of the image forming units pa, pb, pc, and pd contains yellow (Y), magenta (M), cyan (C), and black (B) toners, respectively, and yellow (Y) and magenta. (M), cyan (C), and black (B) toner images are formed on the photoreceptors 101a, 101b, 101c, and 101d, respectively. Primary transfer units 13 a, 13 b, 13 c, and 13 d are disposed via the intermediate transfer belt 11 corresponding to the photoreceptors 101 a, 101 b, 101 c, and 101 d.

  The charging devices 103a, 103b, 103c, and 103d uniformly charge the surfaces of the photoreceptors 101a, 101b, 101c, and 101d, respectively. The exposure unit 10 exposes the surfaces of the photosensitive members 101a, 101b, 101c, and 101d uniformly charged by the charging devices 103a, 103b, 103c, and 103d to electrostatically apply the surfaces of the photosensitive members 101a, 101b, 101c, and 101d. Each latent image is formed. The developing units 102a, 102b, 102c, and 102d respectively develop the electrostatic latent images formed on the surfaces of the photoreceptors 101a, 101b, 101c, and 101d by the exposure unit 10 to form visible images. The toner image T is formed by, for example, toner contained in a non-magnetic one-component developer (non-magnetic toner), a magnetic one-component developer (magnetic toner), or a non-magnetic two-component developer (non-magnetic toner and carrier). .

  The primary transfer units 13a, 13b, 13c, and 13d transfer the visible images formed on the surfaces of the photosensitive members 101a, 101b, 101c, and 101d by the developing units 102a, 102b, 102c, and 102d, respectively, onto the intermediate transfer belt 11. Thus, a toner image (for example, a color toner image) is formed on the intermediate transfer belt 11. The cleaning units 104a, 104b, 104c, and 104d respectively remove residual toner remaining on the surfaces of the photoreceptors 101a, 101b, 101c, and 101d without being transferred to the intermediate transfer belt 11 by the primary transfer units 13a, 13b, 13c, and 13d. Remove. The secondary transfer unit 14 electrostatically transfers the toner image superimposed and transferred onto the intermediate transfer belt 11 by the primary transfer units 13a, 13b, 13c, and 13d onto the recording material P, and the toner image that is not fixed on the recording material P. (For example, a color toner image) is formed. The waste toner box unit 12 collects residual toner remaining on the intermediate transfer belt 11 without being transferred to the recording material P by the secondary transfer unit 14.

  The intermediate transfer belt 11 is stretched around a driving roller 11a and a driven roller 11b. A secondary transfer unit 14 is disposed on the drive roller 11 a side of the intermediate transfer belt 11, and a waste toner box unit 12 is disposed on the driven roller 11 b side of the intermediate transfer belt 11.

  The exposure unit 10 includes four photosensitive members 101a, which are driven to rotate four light beams (specifically, laser beams) from the light source unit 4 including a polygon mirror in the directions of arrows (counterclockwise in FIG. 1). Scanning is performed on the surfaces 101b, 101c, and 101d in the main scanning direction (direction of the rotation axis of the photosensitive member). Specifically, the exposure unit 10 supplies each beam modulated based on image data of a yellow (Y) component, a magenta (M) component, a cyan (C) component, and a black (B) component input from the outside as a light source unit. 4, guided to the photoreceptors 101 a, 101 b, 101 c, 101 d by the mirrors 8 to 8, and uniformly charged by the charging devices 103 a, 103 b, 103 c, 103 d, the photoreceptors 101 a, 101 b, 101 c, 101d is exposed to form an electrostatic latent image on the surface of each of the photoreceptors 101a, 101b, 101c, and 101d.

  The fixing device 15 fixes the unfixed toner image transferred onto the recording material P by the secondary transfer unit 14 onto the recording material P by heat and pressure. The fixing device 15 will be described in detail later.

  The image forming apparatus 100 further includes a pre-transfer charging device 21. The pre-transfer charging device 21 charges the toner image on the intermediate transfer belt 11 prior to the secondary transfer of the toner image on the intermediate transfer belt 11 to the recording material P.

  The image forming apparatus 100 further includes a control device 20 that controls the entire image forming apparatus 100.

  In the image forming apparatus 100 described above, when performing image formation, the surfaces of the photoreceptors 101a, 101b, 101c, and 101d are uniformly charged by the charging devices 103a, 103b, 103c, and 103d, respectively. The surfaces of the bodies 101a, 101b, 101c, and 101d are laser-exposed by the exposure unit 10 in accordance with image data (image information) to form electrostatic latent images on the photoreceptors 101a, 101b, 101c, and 101d, respectively. Here, as the charging devices 103a, 103b, 103c, and 103d, in this example, in order to charge the surfaces of the photoreceptors 101a, 101b, 101c, and 101d uniformly and without generating ozone as much as possible, charging rollers The method is adopted.

  In the image forming apparatus 100, thereafter, the electrostatic latent images formed on the photoconductors 101a, 101b, 101c, and 101d are developed by the developing units 102a, 102b, 102c, and 102d to be visualized as toner images, respectively. The transferred toner image is transferred onto the intermediate transfer belt 11 by the primary transfer units 13a, 13b, 13c, and 13d to which a bias voltage having a polarity opposite to that of the toner is applied. Toner image).

  Next, in the image forming apparatus 100, the toner image formed on the intermediate transfer belt 11 is charged by the pre-transfer charging device 21 immediately before the secondary transfer unit 14, and then the toner image on the intermediate transfer belt 11 is intermediate transferred. The belt 11 is conveyed to the secondary transfer unit 14. On the other hand, the recording material P drawn from the paper feed roller 16a of the internal paper feed unit 16 or the paper feed roller 17a of the manual paper feed unit 17 toward the transport path F and transported through the transport path F is transported by the transport roller. The toner image is conveyed in synchronization with the toner image on the intermediate transfer belt 11 to the secondary transfer unit 14 by r and the registration roller 19. Then, the toner image conveyed to the secondary transfer unit 14 is transferred to the recording material P conveyed to the secondary transfer unit 14 by the secondary transfer unit 14 to which a bias voltage having a polarity opposite to that of the toner is applied. Transcript.

  Next, in the image forming apparatus 100, the toner image transferred onto the recording material P is conveyed to the fixing device 15, and when passing through the fixing device 15, the toner image on the recording material P is heated and pressurized to be on the recording material. Then, the recording material P on which the toner image has been fixed by the fixing device 15 is discharged to the outside of the image forming apparatus 100 by the discharge roller 18a and placed on the discharge tray 18, and the image forming process ends.

  The transport path F includes a reversing path Fr that guides the recording material P transported in the reverse direction by the discharge roller 18a to the upstream side of the registration roller 19 so that the front and back are reversed. When the image forming apparatus 100 forms an image not only on the front surface but also on the back surface of the recording material P, the recording material P is conveyed in the reverse direction from the discharge roller 18a to the reversing path Fr, so that the front and back of the recording material P are reversed. Then, the toner image is guided again to the registration roller 19, and a toner image is formed and fixed on the back surface of the recording material P in the same manner as the front surface of the recording material P, and then discharged outside the image forming apparatus 100 to the discharge tray 18. Place.

[Fixing device]
(First embodiment)
Next, the configuration of the fixing device 15 according to the first embodiment will be described below with reference to FIG.

  FIG. 2 is a cross-sectional view showing a schematic configuration of a main part of the fixing device 15 according to the first embodiment, together with a control configuration of the power source 43 electrically connected to the heating unit 33.

  As shown in FIG. 2, the fixing device 15 includes a fixing member (specifically, a fixing roller 30), a heating member 40, a tension roller 30 and a heating member 40, and one side in the circumferential direction V. The endless fixing belt 32 heated by the heating member 40 while moving in the direction V1 is pressed against the fixing roller 30 via the fixing belt 32, and is pressed against the fixing roller 30 via the fixing belt 32. And a fixing member (specifically, a pressure roller 31) that forms a fixing nip portion N together with the fixing belt 32, and an unfixed image (specifically, a recording material P that passes through the fixing nip portion N). The unfixed toner image T) is fixed to the recording material P.

  Specifically, in the fixing device 15, the recording material P on which the unfixed toner image T is formed in the fixing nip portion N passes through the fixing nip portion N, so that the toner image T is heated and melted and the toner image is transferred to the recording material P. Fix T. When the recording material P passes through the fixing nip portion N, the fixing belt 32 comes into contact with the surface on which the toner image T is formed on the recording material P, while the pressure roller 31 contacts the surface on which the toner image T is formed on the recording material P. Touches the opposite surface.

  The fixing device 15 is disposed on the downstream side of the secondary transfer unit 14 (see FIG. 1) in the conveyance direction W of the recording material P.

  The heating member 40 includes a heating portion 40a1 having a curved shape (curved plate shape) curved convexly toward the fixing belt 32 side. That is, the fixing device 15 uses a heating member 40 having a heating portion 40a1 that is convexly curved (having a curved surface) on the fixing belt 32 side as a heating unit that heats the toner image T on the recording material P. The fixing device is a heating belt fixing type.

  The heating component for heating the fixing belt 32 (heating unit 33 in this example) includes a heating member 40 and a fixing member 41 that bridges and fixes both sides of the heating member 40 in the circumferential direction V. Yes.

  In the present embodiment, the heating member 40 includes a heat generating layer 40d formed in the heating region of the heating unit 40a1. The heating member 40 includes a holding member 40a. The holding member 40 a includes a heating unit 40 a 1, and the outer peripheral surface of the heating unit 40 a 1 is configured to contact the inner peripheral surface 32 a of the fixing belt 32 along the circumferential direction V.

  Specifically, the heating unit 40a1 in the holding member 40a has an arcuate shape that protrudes toward the fixing belt 32 when viewed from the front side (the rotation axis direction of the fixing roller 30). Here, the arc shape is a concept including an arc shape constituting a part of a circular shape and an elliptic arc shape constituting a part of an elliptic shape. In this example, the arc shape is an arc shape. Further, the heating unit 33 including the heating member 40 including the holding member 40a having the arc-shaped heating portion 40a1 and the fixing member 41 that fixes both sides of the heating member 40 in the circumferential direction V is a bow as viewed from the front side. It is a shape.

  Further, the heat generating layer 40d is integrally formed on the inner peripheral surface of the heating unit 40a1 in the holding member 40a.

  In addition, the fixing member 41 has both end portions 40f and 40f in the circumferential direction V of the heating portion 40a1 in the holding member 40a or in the vicinity of the both end portions 40f and 40f (a predetermined distance away from both end portions 40f and 40f inwardly). Position). Here, the fixing member 41 and the holding member 40a can be fixed by a fixing member such as a screw or a heat-resistant adhesive.

  Specifically, the fixing device 15 supplies a predetermined electric power to a temperature sensor (thermistors 35A and 35B in this example) that functions as a temperature detecting unit that detects the surface temperature of the fixing belt 32 and the heat generating layer 40d in the heating member 40. And a power supply 43 to be supplied. The thermistors 35A and 35B are electrically connected to the input system of the control device 20. The temperature sensor detects at least the surface temperature of the central portion in a direction along the surface of the fixing belt 32 perpendicular to the circumferential direction V of the fixing belt 32 (rotation axis direction of the fixing roller 30). In this example, the thermistor 35 </ b> A is provided in the central portion in the rotational axis direction of the fixing roller 30, and the thermistor 35 </ b> B is provided in contact with the fixing belt 32 at either one end (front side or back side).

  The power supply 43 has a power supply system electrically connected to the heat generating layer 40 d and a signal system electrically connected to the output system of the control device 20. Based on the detection signals from the thermistors 35A and 35B, the control device 20 controls the operation of the power supply 43 so that the temperature at the fixing nip N is maintained at a predetermined temperature (for example, the fixing temperature). The energization state to the heat generating layer 40d is controlled. In the present embodiment, the pressure roller 31 is not provided with a heating unit that heats the pressure roller 31. Therefore, the fixing device 15 includes a temperature detection unit that detects the surface temperature of the pressure roller 31. In this example, a temperature sensor (in this example, the thermistor 35 </ b> C) that detects the surface temperature of the pressure roller 31 is preliminarily provided. Specifically, the thermistor 35 </ b> C is provided in a non-contact manner with the pressure roller 31 at the center in the rotation axis direction of the pressure roller 31. The controller 20 detects not only the surface temperature of the fixing belt 32 detected by the detection results of the thermistors 35A and 35B but also the surface temperature of the pressure roller 31 detected by the detection results of the thermistor 35C (for example, the surface temperature of the pressure roller 31 is It is possible to control the temperature of the fixing nip portion N in consideration of whether or not the temperature reaches a predetermined temperature. Therefore, the temperature of the fixing nip portion N can be controlled more accurately. The temperature sensors used in this example are all non-contact types, but may be contact types.

  The fixing roller 30 and the pressure roller 31 are pressed against each other with a predetermined load (for example, 392 N) via the fixing belt 32, and the fixing belt 32, the pressure roller 31, and the like are interposed between the fixing belt 32 and the pressure roller 31. The fixing nip portion N is formed at the pressure contact portion where the two come into contact with each other. In this example, the nip width (the width of the fixing nip portion N in the circumferential direction V) is 7.5 mm. However, the nip width is not limited to this value.

  The fixing roller 30 is in pressure contact with the pressure roller 31 via the fixing belt 32 to form a fixing nip portion N, and is rotated in a predetermined direction R so as to rotate to the outer peripheral surface 30c and the inner periphery of the fixing belt 32. The fixing belt 32 is moved in the direction V1 on one side of the circumferential direction V by frictional resistance with the surface 32a.

  As the fixing roller 30, for example, a two-layer structure in which a core metal 30a and an elastic layer 30b are formed in order from the inside can be used. For the metal core 30a, for example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof can be used. In addition, for the elastic layer 30b, for example, a rubber material such as silicon rubber or fluoro rubber having heat resistance and elastic deformation can be suitably used. In this example, the fixing roller 30 has a diameter of 30 mm, the cored bar 30a is made of hollow or solid stainless steel having a diameter of 15 mm, and the elastic layer 30b is a silicon sponge having a thickness of 7.5 mm. Made of rubber. However, the configuration of the fixing roller 30, the material thereof, and the dimensions of the constituent members constituting the fixing roller 30 are not limited thereto.

  As the pressure roller 31, for example, a three-layer structure in which a core metal 31a, an elastic layer 31b, and a release layer 31c are formed in order from the inside can be used. For the metal core 31a, for example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof can be used. In addition, for the elastic layer 31b, for example, a rubber material such as silicon rubber or fluorine rubber having heat resistance and elastic deformation can be suitably used. For the release layer 31c, for example, a fluororesin such as PFA (copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) or PTFE (polytetrafluoroethylene) can be suitably used. In this example, the pressure roller 31 has a diameter of about 30 mm, and the core 31a is made of an iron alloy having a diameter of 28 mm and a thickness of 1 mm (carbon steel pipe for mechanical structure: STKM), and is elastic. The layer 31b is made of silicon solid rubber having a thickness of 1 mm, and the release layer 31c is made of a PFA tube having a thickness of 30 μm. However, the configuration of the pressure roller 31, the material thereof, and the dimensions of the constituent members constituting the pressure roller 31 are not limited thereto.

  The fixing belt 32 is stretched between the heating member 40 in the heating unit 33 and the fixing roller 30 so that tension is applied at a predetermined pressure. The fixing belt 32 is heated to a predetermined temperature by heat generated by the heating member 40 in the heating unit 33, and heats the recording material P on which the unfixed toner image T passing through the fixing nip N is formed. Is.

  When the fixing roller 30 rotates, the fixing belt 32 is moved in the direction V1 on one side of the circumferential direction V while following the heating roller 40 and slidingly contacting the heating portion 40a1 of the heating member 40.

  As the fixing belt 32, for example, although not shown, a three-layer configuration in which an elastic layer is formed on the surface of a hollow cylindrical base material and a release layer is formed on the surface can be used. As the hollow cylindrical base material, for example, a heat resistant resin such as polyimide, polyamide, and aramid resin, or a metal material manufactured by rolling or electroforming such as stainless steel or nickel can be used. As the elastic layer, for example, an elastomer material (for example, silicon rubber) excellent in heat resistance and elasticity can be used, and as the release layer, for example, a resin material (for example, PFA or the like having excellent heat resistance and releasability) can be used. Fluorine resin such as PTFE) can be used. The elastic layer and the release layer are formed on the outer peripheral side of the fixing belt 32. In the fixing belt 32, when a heat resistant resin such as polyimide is used for the base material, a fluororesin may be internally added. Thus, by internally adding the fluororesin to the base material of the heat resistant resin, the friction resistance with the heating part 40a1 in the heating member 40 can be further reduced, and the sliding load with the heating part 40a1 is reduced accordingly. Can be made. In this example, when the fixing belt 32 is circular, the fixing belt 32 has a diameter of 37 mm, the base material is made of polyimide having a thickness of 50 μm, the elastic layer is made of silicon rubber having a thickness of 150 μm, and the separation belt 32 is separated. The mold layer consists of a PFA tube with a thickness of 20 μm. However, the configuration of the fixing belt 32, its material, and the dimensions of the constituent members constituting the fixing belt 32 are not limited thereto. For example, the release layer may be coated with PFA or PTFE as well as the PFA tube.

  Here, as shown in FIG. 2, the heating unit 33 is disposed so as to be close to the inlet side of the fixing nip N in the conveyance direction W of the recording material P. In other words, the heating unit 33 is disposed so as to be inclined upstream of the fixing nip portion N (the inlet side of the fixing nip portion N) in the conveyance direction W of the recording material P. Specifically, in the heating unit 33, the second imaginary straight line β passing through the fixing roller 30 and the heating member 40 is in the conveyance direction of the recording material P with respect to the first imaginary straight line α passing through the fixing roller 30 and the pressure roller 31. In W, it is arranged so as to incline at a predetermined predetermined inclination angle θ upstream of the fixing nip portion N (on the inlet side of the fixing nip portion N). Specifically, the first virtual straight line α is a virtual straight line along a direction connecting the rotation center of the fixing roller 30 and the rotation center of the pressure roller 31 (vertical direction in this example), and the second virtual straight line β is an imaginary straight line along the direction connecting the rotation center of the fixing roller 30 and the central portion of the heating member 40a1 in the circumferential direction V of the heating member 40. The reason why the heating unit 33 is arranged so as to be close to the inlet side of the fixing nip N in the conveyance direction W of the recording material P will be described below.

  In other words, the heating unit 33 is arranged so as to be close to the exit side of the fixing nip N with respect to the conveyance direction W of the recording material P with the rotation center of the fixing roller 30 in between. In other words, in other words, when the heating unit 33 is disposed so as to be inclined to the downstream side (exit side of the fixing nip N) in the conveyance direction W of the recording material P, the fixing nip N Since the contact angle of the fixing belt 32 with respect to the fixing roller 30 after exiting the fixing roller 30 becomes small, the fixing belt 32 driven by the fixing roller 30 tends to float from the fixing roller 30 immediately after exiting the fixing nip portion N. As described above, when the fixing belt 32 is lifted from the fixing roller 30, the angle of the fixing belt 32 with respect to the recording material P conveyed in the conveyance direction W becomes small, and the peelability of the recording material P may be hindered. is there. Therefore, the heating unit 33 is located closer to the inlet side of the fixing nip portion N with respect to the conveyance direction W of the recording material P, in other words, upstream of the fixing nip portion N in the conveyance direction W of the recording material P. It is preferable to dispose it so as to incline toward the side (inlet side of the fixing nip portion N). In this example, the inclination angle θ at which the heating unit 33 is inclined is not limited thereto, but is 60 °.

  Next, the configuration of the heating unit 33 in the fixing device 15 according to the first embodiment will be described below with reference to FIGS. 3 to 11.

  FIG. 3 is a cross-sectional view showing a schematic configuration of the heating unit 33 in the fixing device 15 according to the first embodiment together with a power source 43 electrically connected to the heating unit 33. FIG. 4 is a schematic configuration diagram showing the heating member 40 that constitutes the heating unit 33 in the fixing device 15 according to the first embodiment. Fig.4 (a) is the front view which looked at the heating member 40 from the front side, and FIG.4 (b) is the side view which looked at the heating member 40 from the inner side. 5 to 7 are schematic configuration diagrams showing a fixing member 41 constituting the heating unit 33 in the fixing device 15 according to the first embodiment. FIG. 5 is a side view of the fixing member 41 viewed from the heating member 40 side, FIG. 6 is a side view of the fixing member 41 viewed from the side opposite to the heating member 40 side, and FIG. It is sectional drawing along the AA line shown in FIG.

  The heating member 40 and the fixing member 41 (see FIG. 3) constituting the heating unit 33 are in the longitudinal direction D (the direction of the rotation axis of the fixing roller 30) that is the direction along the surface of the fixing belt 32 orthogonal to the circumferential direction V. It extends. Further, the heat generating layer 40d is formed on the entire heating area of the heating unit 40a1 or substantially the entire surface. In this example, the heat generating layer 40d is heated excluding predetermined predetermined regions (specifically, regions where power supply layers 40c1 and 40c2 described later are provided) at both ends in the circumferential direction V on the inner peripheral surface of the heating unit 40a1. It is formed entirely in the region. Here, the heating area is an area corresponding to an area for heating the recording material P to the maximum extent.

  The heating unit 33 further includes a pair of power supply electrodes 42 a and 42 b that supply power to the heat generating layer 40 d of the heating member 40. The pair of power supply electrodes 42a and 42b is configured to energize the heat generating layer 40d in the circumferential direction V.

  The pair of power supply electrodes 42a and 42b are arranged at both ends in the direction of bridging the heating member 40 of the fixing member 41 to the fixing member 41 (specifically, the short direction C of the fixing member 41) or in the vicinity of the both ends ( It is provided inside a predetermined distance from both ends).

  In addition, at least one (one in this example) of the pair of power supply electrodes 42a and 42b that energize the heat generating layer 40d in the circumferential direction V (in this example, one of the power supply electrodes 42a (1) to 42a ( n)) (see FIG. 6) are electrically provided independently of each other with respect to the longitudinal direction D of the fixing member 41 (the direction along the surface of the recording material P perpendicular to the conveyance direction W of the recording material P). Yes. Here, n is an integer of 2 or more. In this example, n is 8.

  Only one of the pair of power supply electrodes 42a and 42b that energizes the heat generating layer 40d in the circumferential direction V (42a in this example) is electrically independent from each other in the longitudinal direction D of the fixing member 41. When provided, the following modes can be exemplified.

  That is, any one of the other feeding electrodes (42b in this example) is electrically integrated, and the tip of the other feeding electrode (42b in this example), specifically, the feeding layer (40c2 in this example) ), Or when the power supply layer is not provided, the portion of the other power supply electrode (42b in this example) that contacts the heat generating layer 40d is the one power supply electrode (42a in this example). Correspondingly, it is an aspect that is divided into a plurality in the longitudinal direction D. By doing so, it is possible to easily flow current in the circumferential direction V in the heat generating layer 40d, and individual heat generating regions in the heat generating layer 40d can be clarified. In this case, the power supply layer (for example, 40c2) corresponding to the other power supply electrode (for example, 42b) is electrically separated at the boundary between the other adjacent power supply electrodes, or no power supply layer is provided. In some cases, a slit is provided at the boundary between the other adjacent power supply electrode at the end corresponding to the other power supply electrode (for example, 42b) out of both ends in the circumferential direction V of the heat generating layer 40d. preferable. By doing so, the individual heat generation regions in the heat generation layer 40d can be further clarified.

  In addition, only one of the pair of power supply electrodes 42a and 42b that energizes the heat generating layer 40d in the circumferential direction V (42a in this example) is electrically independent of the longitudinal direction D of the fixing member 41. If a plurality of such devices are provided, the following mode may be adopted.

  That is, a power supply layer (for example, 40c2) corresponding to one of the other power supply electrodes (for example, 42b) is electrically separated at the boundary portion of the one adjacent power supply electrode, or no power supply layer is provided. In such a case, a slit is provided at the boundary between the one adjacent power supply electrode at the end corresponding to the other power supply electrode (for example, 42b) among the both ends in the circumferential direction V of the heat generating layer 40d. is there. By doing so, it is possible to easily flow current in the circumferential direction V in the heat generating layer 40d, and individual heat generating regions in the heat generating layer 40d can be clarified. In this case, the other power supply electrode (for example, 42b) is electrically integrated and the tip of the other power supply electrode (for example, 42b), specifically, a portion that contacts the power supply layer (for example, 40c2), Alternatively, when the power feeding layer is not provided, the portion of the other power feeding electrode (for example, 42b) that contacts the heat generating layer 40d may extend (continuously formed) in the longitudinal direction D, The other power supply electrode (for example, 42b) is electrically integrated and the tip of the other power supply electrode (for example, 42b), specifically, the portion that contacts the power supply layer (for example, 40c2), or the power supply layer Is not provided, the portion of the other power supply electrode (for example, 42b) that contacts the heat generating layer 40d is divided into a plurality of portions in the longitudinal direction D corresponding to the one power supply electrode (for example, 42a). Good.

  Further, the power supply layer (40c1 in this example) corresponding to the plurality of electrically independent power supply electrodes (42a in this example) is electrically divided at the boundary between the adjacent power supply electrodes. Or in the case where no power supply layer is provided, corresponding to the power supply electrodes (42a in this example) on the side where a plurality of the heat generation layers 40d in the circumferential direction V are provided electrically independently. A mode in which a slit is provided at a boundary portion of the adjacent feeding electrode at the end portion to be performed can be exemplified. By doing so, it is possible to further facilitate the flow of current in the circumferential direction V in the heat generating layer 40d, and it is possible to further clarify individual heat generating regions in the heat generating layer 40d.

  Specifically, the heating unit 33 heats the fixing belt 32 by the heating unit 40a1 of the heating member 40 being in contact with the fixing belt 32. As shown in FIG. 3, the heating unit 33 includes a heating member 40, a fixing member 41, and a pair of power supply electrodes 42 a and 42 b, and a power supply 43 that supplies predetermined power to the heat generation layer 40 d of the heating member 40 is a pair of power supplies. It is electrically connected to the electrodes 42a and 42b.

  As shown in FIGS. 3 and 4, the heating member 40 is a multilayer including a heating unit 40 a 1, a first insulating layer 40 b 1, a pair of power feeding layers 40 c 1 and 40 c 2, a heat generating layer 40 d, and a second insulating layer 40 b 2. It has a configuration.

  In this example, the first insulating layer 40b1 is integrally formed over the entire heating area on the inner peripheral surface of the heating unit 40a1. The pair of power feeding layers 40c1 and 40c2 are arranged on the first insulating layer 40b1 inward in the circumferential direction V by a predetermined distance (distance at which the pair of power feeding layers 40c1 and 40c2 are provided) from both ends in the circumferential direction V, and In the longitudinal direction D, they are integrally formed over the entire area. The heat generating layer 40d is disposed on the first insulating layer 40b1 so as to be in electrical contact with the pair of power feeding layers 40c1 and 40c2 between the pair of power feeding layers 40c1 and 40c2 in the circumferential direction V and in the longitudinal direction D. It is integrally formed over. The second insulating layer 40b2 is integrally formed over the entire heat generating layer 40d. Instead of the pair of power supply layers 40c1 and 40c2, the heat generating layer 40d may be integrally formed over the entire area on the first insulating layer 40b1.

  The holding member 40a includes a heating portion 40a1 and a pair of skirt portions 40a2 and 40a3 (plate-like portions) extending from both ends of the heating portion 40a1 in the circumferential direction V toward the fixing roller 30 (FIGS. 3 and 4A). Reference). The holding member 40a has a configuration in which a heating part 40a1 and a pair of skirt parts 40a2 and 40a3 are integrally formed. The fixing member 41 bridges and fixes the pair of skirt portions 40a2 and 40a3 on both sides of the heating member 40 in the circumferential direction V.

  In this example, the heating member 40 has a line-symmetric shape with respect to the second virtual straight line β (see FIG. 2) as viewed from the front side (longitudinal direction D). The pair of skirt portions 40a2 and 40a3 are parallel or substantially parallel to each other along the normal direction E along the second virtual straight line β. That is, the heating member 40 is formed into a semi-cylindrical shape (arch shape) (see FIGS. 3 and 4A) by the heating portion 40a1 and the pair of skirt portions 40a2 and 40a3.

  In this example, the heating member 40 has a size (see FIG. 4), a length L1 (size in the longitudinal direction D) = 320 mm, a width W1 (size in the short direction C) = 23 mm, and a height H1 (normal line). The size of the direction E) = 13 mm. As a material of the holding member 40a, any metal material such as aluminum, stainless steel, iron, copper, titanium can be used. In this example, aluminum having a thickness of 0.3 mm is used as the material of the holding member 40a from the viewpoint of thermal conductivity and corrosion resistance. Note that a fluororesin such as PFA or PTFE is provided on the surface of the holding member 40a (at least the contact surface of the heating unit 40a1 with the fixing belt 32) in order to suppress wear of the fixing belt 32 due to friction with the fixing belt 32. May be coated.

  First, a first insulating layer 40b1 is integrally laminated on a surface (back surface) opposite to the contact surface of the heating unit 40a1 with the fixing belt 32 of the holding member 40a. The first insulating layer 40b1 is provided to insulate the heat generation layer 40d from the electrically conductive holding member 40a so as not to leak electrically. In this example, the first insulating layer 40b1 is made of polyimide having a thickness of 30 μm. However, the present invention is not limited to this, and any insulating material can be used for the first insulating layer 40b1.

  Next, the heat generating layer 40d is integrally formed on the first insulating layer 40b1 at a predetermined distance (distance at which the pair of power feeding layers 40c1 and 40c2 are provided) from both end surfaces in the circumferential direction V of the heat generating layer 40d. Are stacked. As the heat generating layer 40d, any material can be used as long as it is heat resistant and has a predetermined electric resistance value for generating heat by Joule heat. For example, silver palladium or polyimide An electrical resistance material such as a heat-resistant resin such as a conductive filler mixed therein can be used. In this example, the heating layer 40d is made of conductive polyimide having a thickness of 50 μm.

  A pair of power feeding layers 40c1 and 40c2 are integrally laminated on both outer sides in the circumferential direction V of the heat generating layer 40d on the first insulating layer 40b1. In the pair of power feeding layers 40c1 and 40c2, end surfaces on the heat generating layer 40d side in the circumferential direction V are in electrical contact with both end surfaces in the circumferential direction V of the heat generating layer 40d, respectively. The electric resistances of the pair of power feeding layers 40c1 and 40c2 are set to be very low compared to the heat generating layer 40d so as not to generate Joule heat. Therefore, as the material of the pair of power supply layers 40c1 and 40c2, a paste-like composition containing a conductive material can be suitably used. In this example, the pair of power supply layers 40c1 and 40c2 are made of a silver paste having a thickness of 50 μm.

  By the way, in this embodiment, at least one (one in this example) of the pair of power supply electrodes 42a and 42b (in this example, one of the power supply electrodes 42a (1) to 42a (n)) is provided. Although a plurality of electrically independent electrodes are provided in the longitudinal direction D of the fixing member 41, even if a plurality of power supply electrodes are provided independently in this manner, If the energizing directions of the plurality of power feeding electrodes provided independently of each other are not configured to be directed in the circumferential direction V, current flows in the longitudinal direction D in the heat generating layer 40d and flows to the entire heat generating layer 40d. Cheap.

  Therefore, the heating member 40 has a plurality of power supply electrodes (in this example, one of the power supply electrodes 42a (1) to 42a (n) electrically independent of each other) provided in a plurality of electrically independent directions. Are respectively provided in the circumferential direction V.

  For example, a power supply layer corresponding to a plurality of electrically independent power supply electrodes (in this example, one of the power supply electrodes 42a (1) to 42a (n) electrically independent of n pieces) Of the both ends in the circumferential direction V of the heat generating layer 40d when electrically separated at the boundary between one of the adjacent feeding electrodes 42a and 42a or when the pair of feeding layers 40c1 and 40c2 are not provided The one of the end portions corresponding to the plurality of electrically independent feeding electrodes (in this example, one of the feeding electrodes 42a (1) to 42a (n) electrically independent of n pieces) Since the slit is provided at the boundary between the adjacent power supply electrodes 42a and 42a, it is possible to further facilitate the flow of current in the circumferential direction V in the heat generating layer 40d. Provided It is possible to reliably separate heating of Denden each pole.

  In this example, one of the power supply layers 40c1 (see the upper side in FIG. 4) is electrically adjacent to one of the power supply electrodes 42a to 42a provided electrically in the longitudinal direction D as an energization guide portion. An interval S (specifically, a space S1) of a predetermined distance for electrical insulation is provided at a corresponding portion between the electrodes 42a and 42a and is electrically separated.

  Next, the second insulating layer 40b2 is integrally laminated on the heat generating layer 40d. The second insulating layer 40b2 is such that an unnecessary matter such as a foreign substance enters the heating unit 33 and comes into contact with the heat generating layer 40d, so that the heat generating layer 40d is electrically leaked or the heat generating layer 40d is always in the atmosphere. It is provided for the purpose of effectively preventing deterioration of the heat generating layer 40d due to exposure. In this example, the second insulating layer 40b2 is made of polyimide having a thickness of 30 μm. However, the present invention is not limited to this, and the second insulating layer 40b2 can be made of any insulating material like the first insulating layer 40b1.

  The fixing member 41 bridges and fixes both sides of the heating member 40 in the circumferential direction V (in this example, the pair of skirt portions 40a2 and 40a3), and in addition, the heating member 40 is fixed to the inner peripheral surface 32a of the fixing belt 32. And a pair of power supply electrodes 42a and 42b for energizing the heat generating layer 40d.

  As described above, the holding member 40a constituting the heating member 40 is made of an aluminum material having a thickness of 0.3 mm, and the heating unit 33 has a low mechanical strength with the heating member 40 alone. Although it cannot be pressed against the inner peripheral surface 32a with a sufficient load (surface pressure), the heating unit 33 is configured by fixing the heating member 40 with the fixing member 41 as in the present embodiment. The mechanical strength of the fixing belt 32 can be pressed against the inner circumferential surface 32a of the fixing belt 32 with a sufficient load (pressure).

  In this embodiment, the pressing load of the heating member 40 in the heating unit 33 against the fixing belt 32 is 39.2N. For the fixing member 41, for example, a thermosetting resin such as bakelite, a heat resistant resin such as PPS (polyphenylene sulfide) resin or a liquid crystal polymer, or a heat resistant material such as ceramic can be suitably used. These materials not only have excellent insulation properties in addition to heat resistance, but also have high heat insulation properties (low thermal conductivity) compared to metals, so heat generated by the heating member 40 is difficult to escape to the fixing member 41, The thermal efficiency of the fixing device 15 can be improved.

  As shown in FIGS. 5 to 7, the fixing member 41 is composed of a long member (a block body having a substantially hexahedral shape in this example) elongated in the longitudinal direction D. The fixing member 41 has a pair of power supply electrodes 42a and 42b attached to both ends in the lateral direction C or in the vicinity of both ends (in this example, both ends). In this example, the fixing member 41 has a size (see FIGS. 6 and 7), a length L2 (size in the longitudinal direction D) = 320 mm, a width W2 (size in the short direction C) = 22 mm, and a height H2. (Size in the normal direction E) = 4.2 mm, and a liquid crystal polymer is used as the material of the fixing member 41.

  Further, either the surface of the fixing member 41 on the heating member 40 side (hereinafter referred to as the upper surface 41a) or the surface opposite to the heating member 40 side (hereinafter referred to as the lower surface 41b) (in this example, the lower surface 41b). A pair of power supply patterns 44 and 45 (see FIG. 6) is formed.

  A pair of power supply patterns 44 and 45 (see FIG. 6) formed on the lower surface 41b of the fixing member 41 electrically connect the power source 43 (see FIG. 3) side and the pair of power supply electrodes 42a and 42b, respectively. And terminal portions 44a and 45a that are electrically connected to the power source 43 side, and line portions 44b and 45b that electrically connect the terminal portions 44a and 45a and the pair of power supply electrodes 42a and 42b. ing.

  The terminal portions 44a and 45a are provided at both ends in the longitudinal direction D of the fixing member 41. From the viewpoint of facilitating connection of cable wiring from the power source 43, the width is larger than the width of the line portions 44b and 45b. It is getting wider. The pair of power supply patterns 44 and 45 can be formed of a conductive material by an arbitrary forming method. In this example, after a copper plate is attached to the entire lower surface 41b of the fixing member 41, an etching process is performed. It is assumed that a predetermined pattern is formed.

  One power supply pattern 44 of the pair of power supply patterns 44, 45 is provided on one side (right side in FIG. 6) on the lower surface 41 b of the fixing member 41, electrically independently from the central portion in the longitudinal direction D. One power supply electrode 42a to 42a is formed along the longitudinal direction D from one end in the longitudinal direction D, and is electrically connected to the one power supply electrode 42a to 42a. And the other end in the longitudinal direction D one by one with respect to one of the feeding electrodes 42a to 42a provided electrically on the other side (left side in FIG. 6) from the central portion in the longitudinal direction D. Is formed along the longitudinal direction D from the portion, and is electrically connected to one of the power feeding electrodes 42a to 42a on the other side.

  The other power supply pattern 45 of the pair of power supply patterns 44, 45 is at least one of both ends in the longitudinal direction D of the other power supply electrode 42 b that is electrically integrated on the lower surface 41 b of the fixing member 41. Are electrically connected to the end portions (both end portions in this example) from the closer end portions in the longitudinal direction D (one each from the both end portions in this example).

  The pair of power supply electrodes 42a and 42b electrically connect the pair of power supply patterns 44 and 45 and the pair of power supply layers 40c1 and 40c2 in the heating member 40, and are made of a metal such as stainless steel or copper. .

  Each of the pair of power supply electrodes 42a and 42b is a metal plate having elasticity (spring property). Thus, since the pair of power supply electrodes 42a and 42b are both metal plates having elasticity (spring property), the pair of power supply layers with a predetermined pressure due to the elasticity (spring property) of the metal plates. 40c1 and 40c2 can be reliably brought into contact with each other. Moreover, as for a pair of electric power feeding electrode 42a, 42b, as for all, the side which contacts a pair of electric power feeding layer 40c1, 40c2 in the heating member 40 protrudes from the upper surface 41a of the fixing member 41, and free end part 42a1, 42b1 (refer FIG. 7). Is bent in an L shape or substantially L shape inside the short direction C and is inclined toward the inside of the short direction C. As described above, the pair of power supply electrodes 42a and 42b has the free end portions 42a1 and 42b1 bent in an L shape or a substantially L shape inside the short direction C, and toward the inside in the short direction C. By being formed to be inclined, the pair of power feeding layers 40c1 and 40c2 can be stably brought into contact with each other.

  Further, the pair of power supply electrodes 42a and 42b is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41 (specifically, on the heating member 40 side than the lower surface 41b of the fixing member 41) (see FIG. 5). ). In this example, each of the power supply electrodes 42a (1) to 42a (n) that are electrically independent in one power supply electrode 42a is divided into a plurality of parts (specifically, divided into two). It is divided into a plurality of multiples of n (specifically, 16 divisions that are twice as many as n = 8), and the other power supply electrode 42b is divided into the same number as the number of divisions of one power supply electrode 42a (specifically, 16 Divided).

  In other words, as shown in FIG. 6, at least one of the pair of power supply electrodes 42 a and 42 b (one power supply electrode 42 a in this example) is an individual power supply electrode divided on the upper surface 41 a side of the fixing member 41. Are adjacent to each other on the lower surface 41 b side of the fixing member 41. In this example, the other power supply electrode 42 b of the pair of power supply electrodes 42 a and 42 b is integrated with the power supply electrode divided on the upper surface 41 a side of the fixing member 41 on the lower surface 41 b side of the fixing member 41. Accordingly, one of the power supply electrodes 42a is electrically provided independently of n (specifically, eight) and the free ends of the electrically independent power supply electrodes 42a (1) to 42a (n). Each of the portions 42a1 is divided into a plurality of parts (specifically, divided into two parts), and the other feeding electrode 42b is electrically integrated so that the free end part 42b1 is divided into a plurality of times n (specifically, 16 divisions).

  In this way, the pair of power supply electrodes 42a and 42b is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41 (specifically, on the heating member 40 side than the lower surface 41b of the fixing member 41). Compared to the case of an undivided integrated shape, the pair of power feeding layers 40c1 and 40c2 can be contacted more stably. In the present embodiment, the power supply layer (in this example, one power supply layer 40c1) (see the upper side in FIG. 4) corresponds to a portion between the power supply electrodes 42a divided into a plurality (specifically, divided into two). A space S (specifically, a space S2) of a predetermined distance is provided at a place to be electrically separated.

  As shown in FIG. 7, the sides of the pair of power supply electrodes 42a and 42b that are in electrical contact with the pair of power supply patterns 44 and 45 are bent in an L shape inside the short direction C, respectively, and are bent L shapes. The surfaces 42 a 2 and 42 b 2 facing the fixing member 41 in this part are fixed to the fixing member 41 so as to be in close contact with the lower surface 41 b of the fixing member 41.

  The fixing member 41 (see FIGS. 5 and 6) has a comb-like shape having a plurality of concave and convex portions juxtaposed in the longitudinal direction D at both ends in the lateral direction C when viewed from the thickness direction (normal direction E). A pair of power supply electrodes 42a and 42b are fitted in the recesses. The fixing member 41 and the pair of power supply electrodes 42a and 42b can be fixed by a fixing member such as a screw or a heat-resistant adhesive.

  In this way, by configuring the pair of power supply electrodes 42a and 42b and the pair of power supply patterns 44 and 45, n regions (eight in this example) that are independently energized in the longitudinal direction D in the heat generation layer 40d. It is possible to generate heat.

  FIG. 8 is a schematic diagram schematically showing a heat generation area of the heating member 40 in the fixing device 15 according to the first embodiment. In the example shown in FIG. 8, a state where all the regions corresponding to one of the power feeding electrodes 42 a (1) to 42 a (n) of the heat generating layer 40 d are energized is shown.

  As shown in FIG. 8, since the fixing device 15 according to the first embodiment is electrically integrated on the other power supply electrode 42b side, the heat generation area of the heating unit 40a1 is accurately electrically independent. One power supply layer 40c1 electrically connected to one of the provided power supply electrodes 42a (1) to 42a (n) and electrically separated at a predetermined interval S (specifically, space S1). Although it has a trapezoidal shape that slightly extends outward from the side of 40c1 toward the side of the other power feeding layer 40c2 that is electrically connected to the other power feeding electrode 42b, there is no particular problem in actual use, and the area control of heat generation is performed. Rather, the other power supply electrode 42b side is electrically integrated so that the number of heat generation regions can be increased while the shape of the other power supply pattern 45 (see FIG. 6) is simplified. It becomes possible.

  The temperature detection sensor is at least one of the plurality of heat generation regions in the longitudinal direction D of the heating unit 40a1 (regardless of the size of the recording material P and the direction in which the recording material P is conveyed such as vertical conveyance and horizontal conveyance). For example, when the recording material P is transported on the basis of the center, it is configured to detect the surface temperature of the fixing belt 32 corresponding to at least the heat generation region in the central portion. be able to. For example, a plurality of temperature detection sensors can be provided corresponding to the plurality of heat generation regions in the longitudinal direction D of the heating unit 40a1. By doing so, the temperature can be controlled for each of the plurality of heat generating regions.

  Next, a manufacturing method of the heating member 40 for manufacturing the heating member 40 in the fixing device 15 according to the first embodiment will be described below with reference to FIG. The method for manufacturing the heating member 40 can be described in the same manner for the heating member 40 in the fixing device 15 according to the second and third embodiments described later.

  FIG. 9 is an explanatory diagram for explaining a method of manufacturing the heating member 40 in the fixing device 15. FIG. 9A is a diagram showing the first step, and FIG. 9B is a diagram showing the second step.

  The heating member 40 is manufactured by stacking the heat generating layer 40d to form the flat heating member 40 (see FIG. 9A) and forming the heat generating layer 40d in the first step. And a second step (see FIG. 9B) for processing the flat heating member 40 into a kamaboko-shaped heating member 40 by a predetermined bending process (for example, pressing).

  Specifically, in the first step, first, as shown in FIG. 9A, the first insulating layer 40b1 and the heat generating layer are formed on the flat holding member 40a (specifically, a metal plate). 40d, the pair of power feeding layers 40c1 and 40c2, and the second insulating layer 40b2 are sequentially formed by a forming method such as screen printing. Note that the order of forming the heat generating layer 40d and the pair of power feeding layers 40c1 and 40c2 is not limited, and either the heat generating layer 40d or the pair of power feeding layers 40c1 and 40c2 may be formed first.

  Next, after forming all of the first insulating layer 40b1, the heat generating layer 40d, the pair of power feeding layers 40c1 and 40c2 and the second insulating layer 40b2 in the first step, the second step is as shown in FIG. 9B. As shown, a flat holding member 40a formed by laminating a first insulating layer 40b1, a heat generating layer 40d, a pair of power feeding layers 40c1 and 40c2, and a second insulating layer 40b2 is subjected to a predetermined bending process (in this example, gold It is processed into a kamaboko shape (arch shape as viewed from the front side) by pressing using the molds F1 and F2.

  Since stress is applied to each layer during bending, it is more preferable to use a material having flexibility as the material of each layer. Therefore, in this example, a resin material made of polyimide is used for the first insulating layer 40b1 and the second insulating layer 40b2, and a material made of conductive polyimide is used for the heat generating layer 40d. Further, although the pair of power feeding layers 40c1 and 40c2 use silver paste, the pair of power feeding layers 40c1 and 40c2 have a small width in the circumferential direction V, and therefore, the influence of stress due to bending is small.

(About the first embodiment)
As described above, according to the fixing device 15 according to the first embodiment, the heating component for heating the fixing belt 32 (in this example, the heating unit 33) is a curve curved convexly toward the fixing belt 32 side. Since the heating member 40 having the heating part 40a1 having the shape and the fixing member 41 that bridges and fixes both sides of the heating member 40 in the circumferential direction V are included, both sides of the heating member 40 in the circumferential direction V are fixed to the fixing member 41. Can support. Therefore, even if the heating member 40 is thinned to reduce the heat capacity of the heating member 40, the strength of the heating component (heating unit 33 in this example) for heating the fixing belt 32 can be ensured. As a result, the heating member 40 can be strongly pressed against the inner peripheral surface 32a of the fixing belt 32, and as a result, heating loss can be reduced and heating efficiency can be improved.

  By the way, although the heating member 40 is formed into a semi-cylindrical shape in this example, in manufacturing the semi-cylindrical heating member 40, formation of a heat generating layer 40d (in this example, each layer including the heat generating layer 40d) is formed. If it is bent into a kamaboko shape before the step, it becomes difficult to form the heat generating layer 40d (each layer including the heat generating layer 40d in this example) thereon.

  In this regard, according to the manufacturing method of the heating member 40 according to the first embodiment, the first step of manufacturing the flat heating member 40 by stacking the heat generating layer 40d (in this example, each layer including the heat generating layer 40d). Then, the flat heating member 40 in which the heat generating layer 40d (each layer including the heat generating layer 40d in this example) is laminated in the first step is formed into a kamaboko-shaped heating member 40 by a predetermined bending process (pressing process in this example). Specifically, the heating step 40d (each layer including the heating layer 40d in this example) is formed on the flat holding member 40a to form the flat heating member 40. After the production, the heating member 40 having a multilayer structure can be easily processed into a kamaboko shape by bending the flat heating member 40.

  Further, in the first embodiment, the fixing member 41 is made of a heat-resistant resin or ceramic, so that it can be a fixing member that is excellent in heat resistance and excellent in heat insulation compared to metal, Thereby, the heat generated by the heating member 40 can be made difficult to escape to the fixing member 41, and as a result, the thermal efficiency of the heating member 40 can be improved.

  In the first embodiment, the heating member 40 and the fixing member 41 extend in a direction along the surface of the fixing belt 32 orthogonal to the circumferential direction V (specifically, the rotation axis direction of the fixing roller 30). The heating member 40 includes a heat generation layer 40d formed on the heating region of the heating unit 40a1 entirely or substantially entirely, so that the conventional linear shape as described in Patent Documents 3 to 5 described above is provided. Or compared with a strip | belt-shaped heat generating layer, the temperature nonuniformity of the surface of the heating member 40 can be suppressed, and it becomes possible to implement | achieve the lifetime improvement of the heating member 40. FIG.

  Incidentally, the pair of power supply electrodes 42a and 42b for supplying power to the heat generating layer 40d may be configured to supply the heat generating layer 40d in the longitudinal direction D. In this case, however, the length required for supplying the heat generating layer 40d is long. Therefore, the heat generation layer 40d is easily affected by heat generation unevenness due to resistance variation, and temperature unevenness is likely to occur in the longitudinal direction D of the heating member 40.

  Therefore, it is difficult to be affected by heat generation unevenness due to resistance variation of the heat generating layer 40d, and it is desirable to suppress temperature unevenness in the longitudinal direction D of the heating member 40.

"Experimental example"
In this regard, in the fixing device 15 according to the first embodiment, an experiment was performed on the difference in temperature uniformity depending on the direction of energization of the heat generating layer 40d, which will be described below.

  10 and 11 are explanatory diagrams for explaining the difference in temperature uniformity depending on the energization direction to the heat generating layer 40d in the fixing device 15 according to the first embodiment. FIG. 10A is a schematic configuration diagram showing an energization configuration of a pair of power supply electrodes 42a and 42b for energizing the heat generating layer 40d in the longitudinal direction D, and FIG. 10B is a diagram of the pair of power supply electrodes 42a and 42b. 6 is a graph showing a temperature distribution in the longitudinal direction D of the heat generating layer 40d when the heat generating layer 40d is energized in the longitudinal direction D. FIG. 11A is a schematic configuration diagram showing an energization configuration of a pair of power supply electrodes 42a and 42b for energizing the heat generating layer 40d in the circumferential direction V. FIG. 11B is a diagram of the pair of power supply electrodes 42a and 42b. It is a graph which shows the temperature distribution in the longitudinal direction D of the heat generating layer 40d when the heat generating layer 40d is energized in the circumferential direction V by 42b.

  In this experimental example, the heat generating layer 40d is made of the same material regardless of the energizing direction, and a pair of power supply electrodes 42a and 42b are provided at both ends in the longitudinal direction D of the heat generating layer 40d (the energizing direction is the heat generating layer). 40d in the longitudinal direction D) is a first experimental example (see FIG. 10), and a pair of power supply electrodes 42a and 42b are provided at both ends in the circumferential direction V of the heat generating layer 40d (the current flowing direction is the circumferential direction of the heat generating layer 40d). V) was taken as a second experimental example (see FIG. 11).

  The electric resistance of the heat generating layer 40d is 17Ω in the first experimental example and 8Ω in the second experimental example. Between the pair of power supply electrodes 42a and 42b, the voltage is 146V in the first experimental example, and in the second experimental example. The fixing device 15 (fixing nip portion of the fixing belt 32) immediately after warming up from normal temperature to a predetermined temperature (170 degrees) by supplying power of 1,250 W from the power source 43 by applying a voltage of 100 V The temperature variation in the longitudinal direction D of the heating layer 40d on the inlet side of N and the upstream side in the conveyance direction W of the recording material P was measured with a thermotracer.

  As a result, as shown in FIG. 10B, a temperature variation of about 8 degrees occurred in the first experimental example, whereas in the second embodiment, about 3 degrees occurred as shown in FIG. It was found that it was within the temperature variation.

  From the above results, by supplying current in the circumferential direction V of the heat generating layer 40d, it is possible to suppress the influence of heat generation unevenness due to resistance variation of the heat generating layer 40d, and to improve the temperature uniformity in the longitudinal direction D. all right.

  As described above, in the fixing device 15 according to the first embodiment, as described above, the pair of power supply electrodes 42a and 42b that supply power to the heat generating layer 40d is configured to supply the heat generating layer 40d in the circumferential direction V. As a result, the length required for energization of the heat generating layer 40d can be reduced, so that the influence of heat generation unevenness due to resistance variation of the heat generating layer 40d can be suppressed, whereby the temperature in the longitudinal direction D of the heating member 40 is uniform. It becomes possible to improve the property.

  In addition, the pair of power supply electrodes 42 a and 42 b is provided at both ends of the fixing member 41 in the short direction C of the fixing member 41 or in the vicinity of the both ends, so that the heating member 40 of the fixing member 41 is provided. The structure to be fixed can also be used as the structure for supporting the pair of power supply electrodes 42a and 42b, and the structure of the heating component (the heating unit 33 in this example) can be simplified accordingly.

  Further, the fixing member 41 is configured to press the heating member 40 against the inner peripheral surface 32 a of the fixing belt 32, so that the heating member 40 is fixed to the fixing belt 32. This can also be used as a configuration for pressing against the inner peripheral surface 32a, and the configuration of the heating component (the heating unit 33 in this example) can be simplified accordingly.

  By the way, the temperature of the part where the recording material P does not pass in the longitudinal direction D of the heating member 40 is likely to rise compared to the part where the recording material P passes. This is particularly noticeable when images are continuously formed on the recording material P of the same size. Further, the conventional fixing device is configured to heat an area on the recording material P where no image is formed, and consumes power unnecessarily.

  In this regard, in the first embodiment, at least one of the pair of power supply electrodes 42 a and 42 b that energize the heat generating layer 40 d in the circumferential direction V (in this example, one power supply electrode 42 a) is the longitudinal direction of the fixing member 41. With respect to D, a plurality of heat generation areas that are electrically energized independently in the longitudinal direction D of the fixing member 41 can be provided by providing a plurality of them electrically independently from each other, whereby recording materials P of various sizes can be provided. In addition, it is possible to generate heat only in a necessary area for the image forming pattern, and it is possible to suppress an abnormal temperature rise in a portion where the recording material P does not pass in the longitudinal direction D of the heating member 40, thus realizing energy saving. It becomes possible. Here, the control device 20 recognizes in advance the portion where the recording material P does not pass in the longitudinal direction D of the heating member 40 by detecting the size of the recording material P, and the portion of the recording material P where no image is formed based on image data. Can be kept.

  In the first embodiment, the heating member 40 has a plurality of power supply electrodes (in this example, one of the power supply electrodes 42a (1) to 42a (n)) that are electrically provided independently of each other. Energization guide portion directed in the circumferential direction V (specifically, at least one power supply layer of the pair of power supply layers 40c1 and 40c2, in this example, a space S1 that electrically divides one power supply layer 40c1 in the longitudinal direction D) In the heat generating layer 40d, current can be easily flown in the circumferential direction V, and individual heat generation for each of the plurality of power feeding electrodes provided independently in the longitudinal direction D is reliably performed. be able to.

  In the first embodiment, the heating component (the heating unit 33 in this example) is disposed so as to be closer to the inlet side of the fixing nip N in the conveyance direction W of the recording material P. The angle of the fixing belt 32 with respect to the recording material P conveyed in the conveyance direction W after exiting the fixing nip portion N can be increased, thereby avoiding hindering the peelability of the recording material P. be able to.

(Second Embodiment)
Next, the configuration of the fixing device 15 according to the second embodiment will be described below with reference to FIGS.

  FIG. 12 is a schematic configuration diagram illustrating a heating member 40 </ b> A constituting the heating unit 33 in the fixing device 15 according to the second embodiment. FIG. 12A is a front view of the heating member 40A viewed from the front side, and FIG. 12B is a side view of the heating member 40A viewed from the inside. 13 to 15 are schematic configuration diagrams showing a fixing member 41A constituting the heating unit 33 in the fixing device 15 according to the second embodiment. FIG. 13 is a side view of the fixing member 41A viewed from the heating member 40A side, FIG. 14 is a side view of the fixing member 41A viewed from the side opposite to the heating member 40A side, and FIG. FIG. 15 is a cross-sectional view taken along the line BB shown in FIG. 13, and FIG. 15B is a cross-sectional view taken along the line CC shown in FIG.

  The fixing device 15 according to the second embodiment is substantially the same as the fixing device 15 according to the first embodiment except for the heating member 40A, the fixing member 41A, the one power supply electrodes 42aa and 42ab, and the one power supply pattern 44. Therefore, members having the same configuration are denoted by the same reference numerals, and here, the description will focus on points different from the first embodiment.

  At least one of the pair of power supply electrodes (42aa, 42ab), 42b that supplies current to the heat generating layer 40d in the circumferential direction V (one in this example) (in this example, one of the power supply electrodes 42aa (1) to 42aa). 42aa (n1), 42ab (1) to 42ab (n2)) (see FIGS. 13 and 14) are along the surface of the recording material P perpendicular to the longitudinal direction D of the fixing member 41A (the conveyance direction W of the recording material P). With respect to the direction), a plurality of them are provided independently of each other. Here, n1 and n2 are both integers of 1 or more, and n is the sum of n1 and n2. In this example, n1 and n2 are both 8, and n = n1 + n2 is 16.

  In this example, one power supply layer 40c1 (see the upper side in FIG. 12) is adjacent to one of the power supply electrodes 42aa to 42aa and 42ab to 42ab provided in the longitudinal direction D as an energization guide part. A space S (specifically, a space S1) of a predetermined distance for electrical insulation is provided at a corresponding portion between the matching one of the feeding electrodes 42aa and 42ab to be electrically separated. In addition, the other power supply layer 40c2 (see the lower side in FIG. 12) is provided between the other adjacent power supply electrodes 42b and 42b in the other power supply electrodes 42b to 42b divided in the longitudinal direction D as an energization guide portion. A predetermined distance interval S (specifically, space S <b> 1) for electrical insulation is provided at a corresponding portion and is electrically separated.

  As shown in FIGS. 13 to 15, the fixing member 41 </ b> A is composed of a long member that is long in the longitudinal direction D (in this example, a substantially hexahedral block). The fixing member 41A has a pair of power supply electrodes (42aa, 42ab), 42b attached to both ends in the lateral direction C or in the vicinity of both ends (in this example, both ends). In this example, the fixing member 41A has a size (see FIGS. 14 and 15), a length L2 (size in the longitudinal direction D) = 320 mm, a width W2 (size in the short direction C) = 22 mm, and a height H2. (Size in the normal direction E) = 4.2 mm, and a liquid crystal polymer is used as the material of the fixing member 41A.

  Of the pair of power supply patterns 44 and 45, a plurality of electrically independent power supply electrodes (in this example, one of the power supply electrodes 42aa and 42ab) is electrically connected to the power supply pattern (in this example, one of the power supply patterns 44a and 45b). The feeding pattern 44) of the fixing member 41A is a surface (hereinafter referred to as the upper surface 41a) on the heating member 40A side and a surface opposite to the heating member 40A side (hereinafter referred to as the lower surface 41b) (fixing member 41A). On both sides in the thickness direction).

  One power supply pattern 44 (see FIGS. 13 and 14) formed on both surfaces of the fixing member 41A electrically connects the power supply 43 (see FIG. 3) side and one of the power supply electrodes 42aa and 42ab. The terminal portion 44a is electrically connected to the power source 43 side, and the line portion 44b is electrically connected between the terminal portion 44a and one of the power supply electrodes 42aa and 42ab.

  The terminal portion 44a is provided at both end portions in the longitudinal direction D of the fixing member 41A, and the width is wider than the width of the line portion 44b from the viewpoint of facilitating connection of cable wiring from the power source 43. .

  One power supply pattern 44 is electrically connected to one of the power supply electrodes 42ab to 42ab provided on one side (left side in FIG. 13) from the central portion in the longitudinal direction D on the upper surface 41a of the fixing member 41A. In contrast, one by one is formed along the longitudinal direction D from one end in the longitudinal direction D, and is electrically connected to the one feeding electrode 42ab to 42ab on the one side, and electrically independent. One power supply electrode 42ab to 42ab provided on the other side (right side in FIG. 13) than the central portion in the direction D is formed along the longitudinal direction D from the other end in the longitudinal direction D one by one. And electrically connected to one of the power supply electrodes 42ab to 42ab on the other side.

  In addition, one power supply pattern 44 is electrically independent of the lower surface 41b of the fixing member 41A from one of the power supply electrodes 42aa to 42a provided on one side (the right side in FIG. 14) of the central portion in the longitudinal direction D. 42aa each formed from one end in the longitudinal direction D along the longitudinal direction D, electrically connected to the one feeding electrode 42aa-42aa on the one side, and electrically independent. The one feed electrode 42aa to 42aa provided on the other side (left side in FIG. 14) from the central portion in the longitudinal direction D one by one along the longitudinal direction D from the other end in the longitudinal direction D. It is formed and electrically connected to one of the power supply electrodes 42aa to 42aa on the other side.

  The one power supply electrode 42aa, 42ab electrically connects one power supply pattern 44 and one power supply layer 40c1 of the heating member 40A, and is made of a metal such as stainless steel or copper.

  One of the power supply electrodes 42aa and 42ab is a metal plate having elasticity (spring property). In this way, one of the power supply electrodes 42aa and 42ab is a metal plate having elasticity (spring property), so that the one power supply layer 40c1 is applied to the one power supply layer 40c1 with a predetermined pressure by the elasticity (spring property) of the metal plate. It can be made to contact reliably. In addition, one of the power supply electrodes 42aa and 42ab protrudes from the upper surface 41a of the fixing member 41A on the side of the heating member 40A that is in contact with the one power supply layer 40c1, and the free end 42a1 (see FIG. 15) is in the short direction C. It is bent inwardly into an L shape or a substantially L shape, and is inclined toward the inner side in the short direction C. As described above, one of the power supply electrodes 42aa and 42ab has the free end portion 42a1 bent in an L shape or a substantially L shape inside the short direction C and inclined toward the inside in the short direction C. By being formed, it can be stably brought into contact with one of the power supply layers 40c1.

  Further, one of the power supply electrodes 42aa and 42ab is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41A (specifically, on the heating member 40A side than the lower surface 41b of the fixing member 41A) (see FIG. 13). ). In this example, one of the power supply electrodes 42aa and 42ab is divided into n (specifically, divided into 16). In this way, one of the power supply electrodes 42aa and 42ab is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41A (specifically, on the heating member 40A side than the lower surface 41b of the fixing member 41A), Compared to the case of an undivided integrated shape, it is possible to contact the power feeding layer 40c1 more stably.

  One power supply electrode 42aa (1) to 42aa (n1) and one power supply electrode 42ab (1) to 42ab (n2)) are alternately provided on the fixing member 41A. The side that is in electrical contact with one of the power supply patterns 44 of one of the alternately provided power supply electrodes 42aa (1) to 42aa (n1) is located inside the short direction C as shown in FIG. The surface 42a2 facing the fixing member 41A of the bent L-shaped portion is fixed to the fixing member 41A so as to be in close contact with the lower surface 41b of the fixing member 41A. Further, as shown in FIG. 15B, the side of the other power supply electrodes 42ab (1) to 42ab (n2), which are alternately provided, that is in electrical contact with one of the power supply patterns 44 has a short direction C. The surface 42a3 facing the fixing member 41A of the bent acute angle portion is fixed to the fixing member 41A so as to be in close contact with the upper surface 41a of the fixing member 41A, and the free end portion 42a1 (FIG. 15). The tip of (see (b)) is bent in parallel or substantially parallel to the short direction C.

  Further, as shown in FIGS. 13 and 14, the one power supply electrodes 42aa and 42ab are all electrically independent. Accordingly, one power supply electrode 42aa, 42ab is electrically provided independently of n (16 in this example).

  The fixing member 41A (see FIGS. 13 and 14) fills every other concave portion on one side (see the upper side in FIGS. 13 and 14) in the lateral direction C of the comb-shaped fixing member 41 of the first embodiment. Of the one feeding electrode 42aa (1) to 42aa (n1), 42ab (1) to 42ab (n2), one of the feeding electrodes 42aa (1) to 42ab (n2) is alternately provided in the recess. 42aa (n1) are respectively fitted, and the other feeding electrodes 42ab (1) to 42ab (n2) provided alternately are fixed to the portions where the recesses are backfilled. The fixing member 41A and one of the power supply electrodes 42aa and 42ab can be fixed by a fixing member such as a screw or a heat-resistant adhesive.

  In this way, by configuring one of the power supply electrodes 42aa and 42ab and one of the power supply patterns 44, n = n1 + n2 (16 in this example) regions that are energized independently in the longitudinal direction D in the heating layer 40d. It is possible to generate heat. That is, since the power feeding pattern 44 can be formed not only on the lower surface 41b of the fixing member 41A but also on the upper surface 41a of the fixing member 41A, it is independent in the longitudinal direction D of the heat generating layer 40d compared to the first embodiment. It is possible to increase the number of heat-generating regions to be energized to double (in this example, 16 which is 2 times 8).

(About the second embodiment)
According to the fixing device 15 according to the second embodiment, in addition to the operational effects of the fixing device 15 according to the first embodiment, a plurality of power supply electrodes 42aa and 42ab provided electrically independently from each other on the power source 43 side. The power supply pattern 44 for electrically connecting the power supply pattern 44 becomes wider (the area becomes larger) in order to increase the current capacity, and accordingly, the number of electrically independent power supply electrodes (space of the fixing member 41A provided with the power supply pattern) is increased. ) Has a limit, it is provided on both sides in the thickness direction of the fixing member 41A, so that the power supply pattern 44 is provided on one side in the thickness direction of the fixing member 41A as in the first embodiment. The number of electrically independent feeding electrodes can be increased. In this example, compared to the first embodiment, the number of heat generation regions can be increased to 16 heat generation regions, which is twice the eight heat generation regions in the longitudinal direction D of the fixing device 15.

  As a result, it is possible to perform finer temperature control of the heat generation region for various sizes and image formation patterns of the recording material P, and abnormal rise of the portion where the recording material P does not pass in the longitudinal direction D of the heating member 40A. The effect of suppressing the temperature and the effect of suppressing the unnecessary heating in the area where no image is formed can be further improved, thereby contributing to energy saving.

  FIG. 16 is a schematic diagram schematically showing a heat generation region of the heating member 40A in the fixing device 15 according to the second embodiment. Note that the example shown in FIG. 16 shows a state where all the regions corresponding to one of the feeding electrodes 42aa (1) to 42aa (n1) and 42ab (1) to 42ab (n2) of the heat generating layer 40d are energized.

  As shown in FIG. 16, in the fixing device 15 according to the second embodiment, one power supply layer 40c1 and the other power supply layer 40c2 are both electrically provided with a predetermined interval S (specifically, a space S1). Therefore, the heat generation region of the heating unit 40a1 is precisely one of the power supply electrodes 42aa (1) to 42aa (n1) and 42ab (1) to 42ab (n2) which are electrically provided independently. ) At the center in the lateral direction C between the one power supply layer 40c1 to 40c1 side electrically connected to the other power supply electrode 40b and the other power supply layer 40c2 to 40c2 side electrically connected to the other power supply electrode 42b. However, there is no particular problem in actual use, and the area control of heat generation can be more reliably performed.

  In addition, the other power supply layer 40c2 is electrically insulated as a current-carrying guide portion at a portion corresponding to the space between the other power supply electrodes 42b and 42b adjacent to each other in the other power supply electrodes 42b to 42b divided in the longitudinal direction D. By providing a predetermined distance interval S (specifically, space S1) for electrical separation, the individual heat generation regions in the heat generation layer 40d can be made clearer.

  In the second embodiment, as in the first embodiment, the other power feeding layer 40c2 may be formed integrally (continuously in the longitudinal direction D). Further, in the first embodiment, as in the second embodiment, both the one power supply layer 40c1 and the other power supply layer 40c2 are provided with a predetermined interval S (specifically, space S1) and are electrically separated. May be.

(Third embodiment)
Next, the configuration of the fixing device 15 according to the third embodiment will be described below with reference to FIGS.

  FIGS. 17 to 19 are diagrams showing a schematic configuration of a fixing member 41B constituting the heating unit 33 in the fixing device 15 according to the third embodiment. 17 is a side view of the fixing member 41B viewed from the heating member 40 side, FIG. 18 is a side view of the fixing member 41B viewed from the side opposite to the heating member 40 side, and FIG. It is sectional drawing along the DD line shown in FIG.

  Note that the fixing device 15 according to the third embodiment is the first except for the fixing member 41B, one power supply electrode 42a, one power supply pattern 44, the switching elements 46a (1) to 46a (n), and the signal line 47. Since the configuration is substantially the same as that of the fixing device 15 according to the embodiment, members having the same configuration are denoted by the same reference numerals, and here, differences from the first embodiment will be mainly described.

  At least one (one in this example) of the pair of power supply electrodes 42a and 42b for energizing the heat generating layer 40d in the circumferential direction V (in this example, one of the power supply electrodes 42a (1) to 42a (n)) ) (See FIG. 17 and FIG. 18) are provided in a plurality electrically independent from each other with respect to the longitudinal direction D of the fixing member 41B (the direction along the surface of the recording material P perpendicular to the conveyance direction W of the recording material P) ing. In this example, n is 16.

  In the present embodiment, the plurality of power supply electrodes 42a (1) to 42a (n) provided electrically independently are individually switched by the switching elements 46a (1) to 46a (n) (see FIG. 18). Connected.

  In the present embodiment, switching elements 46a (1) to 46a (n) are made of a silicon carbide (SiC) semiconductor.

  As shown in FIGS. 17 to 19, the fixing member 41 </ b> B is composed of a long member that is long in the longitudinal direction D (in this example, a substantially hexahedral block). The fixing member 41B has a pair of power supply electrodes 42a and 42b attached to both ends in the lateral direction C or in the vicinity of both ends (in this example, both ends). In this example, the size of the fixing member 41B (see FIGS. 18 and 19) is a length L2 (size in the longitudinal direction D) = 320 mm, a width W2 (size in the short direction C) = 22 mm, and a height H2. (Size in the normal direction E) = 4.2 mm, and a liquid crystal polymer is used as the material of the fixing member 41B.

  Then, among the pair of power supply patterns 44 and 45, a power supply pattern (one power supply in this example) electrically connected to a plurality of power supply electrodes (in this example, one power supply electrode 42a) provided independently. The pattern 44) is one of the surfaces of the fixing member 41B on the heating member 40 side (hereinafter referred to as the upper surface 41a) and the surface opposite to the heating member 40 side (hereinafter referred to as the lower surface 41b) (in this example). It is provided on the lower surface 41b).

  One power supply pattern 44 (see FIG. 18) formed on the lower surface 41b of the fixing member 41B electrically connects the power supply 43 (see FIG. 3) side and the one power supply electrode 42a. And a line portion 44b for electrically connecting the terminal portion 44a and the one feeding electrode 42a via the switching elements 46a (1) to 46a (n). ing.

  The terminal portion 44a is provided at both end portions in the longitudinal direction D of the fixing member 41B, and the width is wider than the width of the line portion 44b from the viewpoint of facilitating connection of cable wiring from the power source 43. .

  The line portion 44b is composed of one bus line portion 44b1 and a plurality of connection line portions 44b2, and a plurality of power supply electrodes 42a (1) provided electrically independently from the bus line portion 44b1. To 42a (n), one connection line portion 44b2 branches and is electrically connected via the power terminals of the switching elements 46a (1) to 46a (n).

  Further, as shown in FIG. 17, a signal line 47 is formed on the upper surface 41a of the fixing member 41B. The signal line 47 electrically connects the control device 20 (see FIG. 2) and the switching elements 46a (1) to 46a (n). Thereby, a control signal can be sent from the control device 20 to the switching elements 46a (1) to 46a (n). The signal line 47 is electrically connected to the terminal portion 47a electrically connected to the control device 20 side and between the terminal portion 47a and the signal terminals of the switching elements 46a (1) to 46a (n). It consists of part 47b.

  The terminal portion 47a is provided at both ends in the longitudinal direction D of the fixing member 41B, and from the viewpoint of facilitating connection of a signal line (harness) from the control device 20, the width is larger than the width of the line portion 47b. It is getting wider. Further, since the pair of power feeding patterns 44 and 45 are on the primary side, the signal line 47 is on the secondary side, and therefore the width of the secondary side terminal portion 47a is the primary side terminal portions 44a and 45a. Smaller than that.

  One power supply electrode 42a electrically connects one power supply pattern 44 and one power supply layer 40c1 of the heating member 40, and is made of a metal such as stainless steel or copper.

  One power supply electrode 42a is a metal plate having elasticity (spring property). As described above, the one power supply electrode 42a is a metal plate having elasticity (spring property), so that the elasticity (spring property) of the metal plate reliably ensures that the one power supply layer 40c1 has a predetermined pressure. It can be made to contact. In addition, one power supply electrode 42a protrudes from the upper surface 41a of the fixing member 41B on the side of the heating member 40 that contacts the one power supply layer 40c1, and the free end 42a1 (see FIG. 19) is inward in the short direction C. It is formed to be bent in an L shape or a substantially L shape and to be inclined toward the inner side in the short direction C. As described above, the one feeding electrode 42a is formed such that the free end portion 42a1 is bent in an L shape or a substantially L shape inside the short direction C and is inclined toward the inside in the short direction C. As a result, it is possible to stably contact one power supply layer 40c1.

  Further, one power supply electrode 42a is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41B (specifically, on the heating member 40 side of the lower surface 41b of the fixing member 41B) (FIGS. 17 and 18). reference). In this example, one power supply electrode 42a is divided into n parts (specifically, 16 parts). In this way, one power supply electrode 42a is divided into a plurality of parts in the longitudinal direction D on the upper surface 41a side of the fixing member 41B (specifically, on the heating member 40A side than the lower surface 41b of the fixing member 41). Compared to the case of the integral shape that is not, it is possible to contact the power feeding layer 40c1 more stably.

  The side of one of the power supply electrodes 42a (1) to 42a (n) that is in electrical contact with one of the power supply patterns 44 is bent in an L shape inside the short direction C and bent as shown in FIG. The surface of the L-shaped portion facing the fixing member 41B is fixed to the fixing member 41B so as to be in close contact with the lower surface 41b of the fixing member 41B.

  Moreover, as shown in FIGS. 17 and 18, all of the one feeding electrode 42a are electrically independent. Therefore, one feeding electrode 42a is electrically provided independently in n pieces (16 pieces in this example).

  The fixing member 41B (see FIGS. 17 and 18) has a comb-like shape having a plurality of concave and convex portions juxtaposed in the longitudinal direction D at both ends in the lateral direction C when viewed from the thickness direction (normal direction E). A pair of power supply electrodes 42a and 42b are fitted in the recesses, respectively. The fixing member 41B and the pair of power supply electrodes 42a and 42b can be fixed by a fixing member such as a screw or a heat-resistant adhesive.

  The switching elements 46 a (1) to 46 a (n) are turned on by energization of one of the power supply electrodes 42 a (1) to 42 a (n) that are provided electrically independently by an instruction signal from the control device 20. -Control off.

  In addition, the switching elements 46a (1) to 46a (n) have a plurality of (in this example, 16) connection terminals 46c (1) to 46c (n) whose signal terminals are provided on the upper surface 41a of the fixing member 41B. Thus, they are electrically connected through conductive cables 46b (1) to 46b (n) (see FIG. 19) that penetrate the fixing member 41B in the thickness direction. Further, the plurality of signal lines 47 to 47 are electrically connected to the plurality of connection terminals 46c (1) to 46c (n), respectively.

  On the upper surface 41a of the fixing member 41B, the signal line 47 is one side in the longitudinal direction D one by one with respect to the connection terminals 46 to 46 provided on one side (left side in FIG. 17) from the central portion in the longitudinal direction D. Is formed along the longitudinal direction D from the end of the terminal and is electrically connected to the connection terminals 46 to 46 on one side, and provided on the other side (right side in FIG. 17) from the central portion in the longitudinal direction D. The connecting terminals 46 to 46 are formed one by one from the other end in the longitudinal direction D along the longitudinal direction D and are electrically connected to the other connecting terminals 46 to 46.

  As the switching elements 46a (1) to 46a (n), any semiconductor element can be used. However, since the inside of the fixing device 15 becomes extremely high and heat resistance is required, in this example, A silicon carbide (SiC) semiconductor having excellent heat resistance is used.

  FIG. 20 is a schematic diagram schematically showing a heat generation region of the heating member 40 in the fixing device 15 according to the third embodiment. Note that the example shown in FIG. 20 shows a state where all the regions corresponding to one of the power supply electrodes 42a (1) to 42a (n) of the heat generating layer 40d are energized.

  As shown in FIG. 20, in the fixing device 15 according to the third embodiment, since the other power supply electrode 42b side is electrically integrated, the heating area of the heating unit 40a1 is accurately electrically independent. One power feeding layer 40c1 to 40c1 electrically connected to one of the power feeding electrodes 42a (1) to 42a (n) provided The other power feeding layer 40c2 side electrically connected to the other power feeding electrode 42b However, there is no particular problem in actual use, and the area control of heat generation can be reliably performed, and the other feeding electrode 42b side is configured to be electrically integrated. Thus, it is possible to increase the number of heat generating regions while simplifying the shape of the other power feeding pattern 45 (see FIG. 18).

  In the third embodiment, as in the second embodiment, both the power feeding layer 40c1 and the other power feeding layer 40c2 are electrically separated by providing a predetermined interval S (specifically, space S1). May be.

(About the third embodiment)
According to the fixing device 15 according to the third embodiment, in addition to the operational effects of the fixing device 15 according to the first embodiment, a plurality of power feeding electrodes 42a (1) to 42a (n) that are provided electrically independently from each other. ) Indicates that the switching elements 46a (1) to 46a (n) are electrically connected to each other, thereby turning on / off the energization of the divided power supply electrodes 42a (1) to 42a (n). Control can be performed easily and easily.

  In the third embodiment, although the atmospheric temperature inside the fixing device 15 is high, the switching elements 46a (1) to 46a (n) are made of silicon carbide (SiC) semiconductor, so Therefore, the switching element is suitable for the switching element used in the fixing device 15.

  In addition, the heat generation region can be controlled by the switching elements 46a (1) to 46a (n), thereby reducing the number of power supply patterns that require a certain width (area) to flow a large current. it can. In this example, as compared with the first embodiment, it is possible to increase from eight heat generation areas to 16 heat generation areas in the longitudinal direction D of the fixing device 15. Therefore, finer heat generation area control can be performed.

  As a result, it is possible to perform finer temperature control of the heat generation area for various sizes and image formation patterns of the recording material P, and abnormal rise of the portion where the recording material P does not pass in the longitudinal direction D of the heating member 40. The effect of suppressing the temperature and the effect of suppressing unnecessary heating in an area where no image is formed can be further improved, which can contribute to energy saving.

(Other embodiments)
In the first embodiment, the pair of power supply electrodes 42 a and 42 b are provided in close contact with the lower surface 41 b of the fixing member 41, but may be provided in close contact with the upper surface 41 a of the fixing member 41. In this case, the pair of power supply patterns 44 and 45 can be formed on the upper surface 41 a of the fixing member 41.

  In the second embodiment, the other power supply electrode 42b is provided in close contact with the lower surface 41b of the fixing member 41A, but may be provided in close contact with the upper surface 41a of the fixing member 41A. In this case, the other power feeding pattern 45 can be formed on the upper surface 41 a of the fixing member 41.

  In the third embodiment, the pair of power supply electrodes 42 a and 42 b are provided in close contact with the lower surface 41 b of the fixing member 41, but may be provided in close contact with the upper surface 41 a of the fixing member 41. In this case, the pair of power supply patterns 44 and 45 can be formed on the upper surface 41 a of the fixing member 41, and the switching elements 46 a (1) to 46 a (n) can be provided on the upper surface 41 a of the fixing member 41. The signal line 47 can be formed on the lower surface 41 b of the fixing member 41, and the connection terminal 46 c can be provided on the lower surface 41 b of the fixing member 41.

  The present invention is not limited to the embodiment described above, and can be implemented in various other forms. Therefore, such an embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is shown by the scope of claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention is applicable to a fixing device provided in an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, and an MFP.

100 Image forming apparatus 15 Fixing apparatus 20 Control apparatus 30 Fixing roller (an example of a fixing member)
30a Metal core 30b Elastic layer 30c Outer peripheral surface 31 of fixing roller Pressure roller (an example of a pressure member)
31a Metal core 31b Elastic layer 31c Release layer 32 Fixing belt 32a Inner circumferential surface 33 of fixing belt Heating unit (an example of a heating component)
35A thermistor 35B thermistor 35C thermistor 40 heating member 40A heating member 40a holding member 40a1 heating part 40a2 skirt part 40b1 first insulating layer 40b2 second insulating layer 40c1 one feeding layer 40c1 other feeding layer 40d heat generating layer 40f both ends 41 fixing member 41A fixing member 41B fixing member 41a upper surface 41b of fixing member lower surface 42a of fixing member one feeding electrode 42a1 free end 42aa one feeding electrode 42ab one feeding electrode 42b other feeding electrode 42b1 other feeding electrode 42b1 free end 43 power supply 44 One power supply pattern 44a Terminal section 44b Line section 44b1 Bus line section 44b2 Connection line section 45 The other power supply pattern 46a Switching element 46b Cable 46c Connection terminal 47 Signal line 47a Terminal section 47 Line unit C widthwise direction D longitudinally E normal direction N fixing nip P the recording material S spacing S1 space (an example of a current guiding portion)
S2 Space T Toner image V Circumferential direction V1 One direction of circumferential direction W Conveying direction α First virtual straight line β Second virtual straight line θ Inclination angle

Claims (13)

A fixing member, a heating member, an endless fixing belt that is stretched between the fixing member and the heating member and that is heated by the heating member while moving to one side in the circumferential direction; and the fixing belt And a pressure member that forms a fixing nip portion together with the fixing belt at a pressure contact portion with the fixing member via the fixing belt, and passes through the fixing nip portion. A fixing device for fixing an unfixed image on a material to the recording material,
The heating member has a curved heating portion that is convexly curved toward the fixing belt,
The heating device for heating the fixing belt includes the heating member and a fixing member that bridges and fixes both sides of the heating member in the circumferential direction. The fixing device according to claim 1,
The fixing device, wherein the fixing member is made of a heat resistant resin or ceramic. The fixing device according to claim 1 or 2,
The heating member and the fixing member extend in a direction along the surface of the fixing belt orthogonal to the circumferential direction,
The fixing device according to claim 1, wherein the heating member includes a heat generating layer formed on the entire heating area of the heating unit. The fixing device according to claim 3,
A pair of power supply electrodes for supplying power to the heat generating layer is configured to supply current to the heat generating layer in the circumferential direction. The fixing device according to claim 3 or 4, wherein:
A fixing device, wherein a pair of power supply electrodes for supplying power to the heat generating layer is provided at or near both ends of the fixing member in a short direction of the fixing member. The fixing device according to claim 4 or 5, wherein:
Among the pair of power supply electrodes for energizing the heat generating layer in the circumferential direction, at least one power supply electrode is provided in a plurality electrically independent from each other in the longitudinal direction of the fixing member. Fixing device. The fixing device according to claim 6, wherein
The fixing device according to claim 1, wherein the heating member is provided with an energization guide portion that directs the energization directions of the plurality of power supply electrodes provided independently of each other in the circumferential direction. The fixing device according to claim 6 or 7, wherein
The power supply pattern that electrically connects a plurality of power supply electrodes that are electrically independent from each other and the power supply side is provided on both sides in the thickness direction of the fixing member. apparatus. A fixing device according to any one of claims 6 to 8,
The fixing device according to claim 1, wherein a plurality of the feeding electrodes provided independently of each other are individually connected to a switching element. The fixing device according to claim 9, wherein
The fixing device, wherein the switching element is made of a silicon carbide (SiC) semiconductor. A fixing device according to any one of claims 1 to 10, wherein
The fixing device according to claim 1, wherein the heating component is disposed so as to be close to an inlet side of the fixing nip portion with respect to a conveyance direction of the recording material.   An image forming apparatus comprising the fixing device according to claim 1. A manufacturing method of a heating member for manufacturing the heating member in the fixing device according to any one of claims 1 to 11,
A first step of forming a flat heating member by laminating a heating layer;
And a second step of processing the flat heating member formed by laminating the heat generating layer in the first step into a kamaboko-shaped heating member by a predetermined bending process. Method.

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