JP6425526B2 - Fixing device and image forming apparatus provided with the same - Google Patents

Description

The present invention relates to a fixing device for use in an image forming apparatus such as a copying machine, a printer, a facsimile, and a multi-function machine (MFP: Multi Function Printer), and more particularly to a fixing device of a sheet heating belt fixing method and an image forming apparatus comprising the same. about the location.

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

  As such a fixing device, a heat roller fixing type fixing device is widely used. The fixing device of the heat roller fixing type is a heat source such as a roller pair (specifically, a fixing roller and a pressure roller) pressed against each other, and a halogen heater disposed inside one or both of the roller pair. And have. The heat roller fixing type fixing device heats the roller pair to a predetermined temperature (fixing temperature) by a heat source, and then supplies the recording material on which the unfixed image is formed to the fixing nip portion, which is a pressure contact portion of the roller pair. 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, it is common to use an elastic roller provided with an elastic layer made of an elastic member such as silicone rubber on the surface as a fixing roller. By using the fixing roller as an elastic roller, the surface of the fixing roller is elastically deformed corresponding to the unevenness of the unfixed toner image, and contacts so as to cover the image surface of the toner image. Therefore, it is possible to perform heat fixing well on an unfixed toner image in color image formation having a large toner amount as compared with monochrome image formation. Further, due to the strain releasing effect of the elastic layer at the fixing nip portion, it is possible to improve the releasability with respect to the color toner which is easily offset as compared with the monochrome toner. Furthermore, since the nip shape of the fixing nip portion is convex on the toner image side (fixing roller side) (so-called reverse nip shape), the peeling performance of the recording material can be improved, and peeling means such as peeling nails Even without use, reliable peeling of the recording material is possible (self-stripping), and image defects caused by the peeling means can be eliminated.

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

  However, in the case of a fixing roller having a thick elastic layer, the thermal conductivity of the elastic layer is lower than that of a member having excellent thermal conductivity such as metal. Therefore, inside the fixing roller like a fixing device of a heat roller fixing type. When the heat source is provided, when the process speed is increased, heat supply from the heat source to the elastic layer of the fixing roller becomes insufficient, which causes a problem that the surface temperature of the fixing roller can not follow. On the other hand, in the case of a fixing roller having a large roller diameter, the curvature is reduced and the nip width of the fixing nip portion can be increased, but the heat capacity is increased by the increased roller diameter and the warm-up time (surface of fixing roller There is a disadvantage that the time required for the temperature to reach a predetermined temperature increases, and the power consumption increases.

  In order to solve such problems, various configurations have been proposed as fixing devices provided in image forming apparatuses in recent years.

  For example, Patent Document 1 discloses a fixing device of an external belt heating fixing system in which the fixing roller is externally heated using an external heating belt. 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.

  Further, 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 the fixing belt is stretched between the fixing roller and the heating roller. There is disclosed a belt fixing type fixing device (belt fixing device) in which the fixing roller and the pressure roller are brought into pressure contact with each other via a fixing belt. In this belt fixing device, since the fixing belt having a heat capacity smaller than that of the fixing roller is heated, the warm-up time can be further shortened.

  In any of the external belt heating and fixing method and the belt fixing method described above, it is not necessary to incorporate a heat source such as a halogen lamp in the fixing roller, so the fixing roller is made of elastic material such as sponge rubber. A thick layer can be provided, and a wide nip width can be secured.

  Further, 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 convexly curved to the fixing belt side is used as a heating unit. A sheet-type heat generating belt fixing type fixing device (a sheet-type heat generating belt fixing device) is disclosed. In this flat heat generating belt fixing device, since the heat generating layer is formed on the heating member as the heat source, the heat capacity of the heating means is smaller than that of the conventional heating roller, and the heating member as the heating means (specifically Surface heater directly generates heat. From this, the thermal responsiveness is improved as compared with a fixing device of a belt fixing type in which the heating roller is indirectly heated using a heat source such as a halogen lamp, and the warm-up time is further shortened and energy saving is further realized. Can be achieved.

Unexamined-Japanese-Patent No. 2007-212896 (August 23, 2007 publication) Japanese Patent Application Laid-Open No. 10-307496 (released on November 17, 1998) Unexamined-Japanese-Patent No. 2002-333788 (Nov. 22, 2002 publication) Unexamined-Japanese-Patent No. 2003-287969 (October 10, 2003 publication) Unexamined-Japanese-Patent No. 2006-293051 (October 26, 2006 publication)

  However, in the conventional planar heat-generating belt fixing device, since the heating component for heating the fixing belt is constituted only by the heating member, for example, when the heating member is made thinner 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 can not be strongly pressed against the inner peripheral surface of the fixing belt, so a minute gap is easily formed between the heating member and the fixing belt. Then, the heating loss becomes large and the heating efficiency becomes low.

Therefore, 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 secured, thereby fixing the heating member. it can strongly pressed against the inner peripheral surface of the belt, thus, an object of the invention to provide a fixing device and an image forming equipment having the same can improve the heating efficiency by reducing heat loss.

The present invention, in order to solve the above problems, to provide a fixing device and an image forming equipment of the fourth aspect of the following first aspect.

(1) The Fixing Device of the First Aspect An endless form stretched between a fixing member, a heating member, the fixing member and the heating member, and being heated by the heating member while moving to one side in the circumferential direction And a pressure member which is in pressure contact with the fixing member via the fixing belt and which forms a fixing nip portion 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 the fixing nip portion to the recording material, wherein the heating member has a heating portion having a curved shape convexly curved toward the fixing belt side. The heating component for heating the fixing belt includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction, and the heating member and the fixing member , Said The heating member extends in a direction along the surface of the fixing belt orthogonal to the circumferential direction, and the heating member includes a heat generating layer formed entirely or substantially entirely in the heating area of the heating unit, and the heat generation A pair of feed electrodes for feeding a layer is configured to energize the heat generating layer in the circumferential direction, and at least one of the pair of feed electrodes for energizing the heat generating layer in the circumferential direction. A plurality of feed electrodes are provided so as to be electrically independent of each other in the longitudinal direction of the fixing member, and a feed pattern electrically connected to the power supply side and the plurality of feed electrodes electrically provided separately from each other. The fixing device is provided on both sides with respect to the thickness direction of the fixing member .
(2) The fixing device of the second aspect
An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material, wherein the heating member has a heating unit having a curved shape convexly curved toward the fixing belt side, and is for heating the fixing belt. The heating component includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction, and the heating member and the fixing member are fixed to be orthogonal to the circumferential direction. The heating member includes a heat generating layer formed entirely or substantially entirely in the heating area of the heating unit, extending in a direction along the surface of the rut, and a pair of power feedings for supplying power to the heat generating layer. The electrode is configured to energize the heat generating layer in the circumferential direction, and at least one of the pair of power supply electrodes for energizing the heat generating layer in the circumferential direction is the fixing member. The plurality of feed electrodes provided so as to be electrically independent of each other in the longitudinal direction and provided so as to be electrically independent from each other are characterized in that the switching elements are electrically connected individually. Fixing device.
(3) The fixing device of the third aspect
An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material, wherein the heating member has a heating unit having a curved shape convexly curved toward the fixing belt side, and is for heating the fixing belt. The heating component includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction, and the heating member and the fixing member are fixed to be orthogonal to the circumferential direction. The heating member includes a heat generating layer formed entirely or substantially entirely in the heating area of the heating unit, extending in a direction along the surface of the rut, and a pair of power feedings for supplying power to the heat generating layer. The electrodes are provided at both ends of the fixing member in the lateral direction of the fixing member or in the vicinity of the both ends with respect to the fixing member, and at least at least one of the pair of feeding electrodes for energizing the heat generating layer in the circumferential direction. A plurality of any one of the feed electrodes are provided so as to be electrically independent of each other in the longitudinal direction of the fixing member, and a plurality of the feed electrodes electrically independent of each other from the power supply side are electrically connected. The fixing device is characterized in that the feed patterns to be connected are provided on both sides in the thickness direction of the fixing member.
(4) The fixing device of the fourth aspect
An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material, wherein the heating member has a heating unit having a curved shape convexly curved toward the fixing belt side, and is for heating the fixing belt. The heating component includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction, and the heating member and the fixing member are fixed to be orthogonal to the circumferential direction. The heating member includes a heat generating layer formed entirely or substantially entirely in the heating area of the heating unit, extending in a direction along the surface of the rut, and a pair of power feedings for supplying power to the heat generating layer. The electrodes are provided at both ends of the fixing member in the lateral direction of the fixing member or in the vicinity of the both ends with respect to the fixing member, and at least at least one of the pair of feeding electrodes for energizing the heat generating layer in the circumferential direction. A plurality of any one feed electrodes are provided electrically independently of each other in the longitudinal direction of the fixing member, and a plurality of the feed electrodes provided electrically independently of each other are individually provided with switching elements. The fixing device is characterized in that it is connected to each other.

( 5 ) Image Forming Apparatus An image forming apparatus comprising the fixing device according to the first, second, third or fourth aspect of the present invention.

  In the present invention, the fixing member can be exemplified by an embodiment made of a heat resistant resin or ceramic.

  In the present invention, the pair of feeding electrodes for feeding power to the heat generating layer may be configured to supply the heat generating layer in the circumferential direction.

  In the present invention, it is possible to exemplify an aspect in which the heating member is provided with a conduction guide portion which respectively directs the conduction direction of the plurality of feed electrodes electrically independent of each other in the circumferential direction.

  In the present invention, the plurality of feed electrodes provided independently of each other electrically can individually illustrate the aspect in which the switching elements are electrically connected.

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

  In the present invention, the heating component may be disposed close to the entrance side of the fixing nip portion in the conveying direction of the recording material.

According to the present invention, even if the heating member is thinned in order to reduce the heat capacity of the heating member, the strength of the heating component for heating the fixing belt can be secured, whereby the heating member is fixed to the fixing belt push it can shed strongly on the inner peripheral surface, and thus, it is possible to provide an image forming equipment having a fixing device and it can improve the heat efficiency by reducing heat loss.

FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus provided with a fixing device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a schematic configuration of a main part of the fixing device according to the first embodiment together with a control configuration of a power supply electrically connected to a heating unit. FIG. 2 is a cross-sectional view showing a schematic configuration of a heating unit in the fixing device according to the first embodiment together with a power supply electrically connected to the heating unit. FIG. 6 is a schematic configuration view showing a heating member constituting the heating unit in the fixing device according to the first embodiment, wherein (a) is a front view of the heating member as viewed from the front side, and (b) is a heating member It is the side view which looked at from inside. FIG. 5 is a schematic configuration view showing a fixing member constituting the heating unit in the fixing device according to the first embodiment, and is a side view of the fixing member as viewed from the heating member side. FIG. 7 is a schematic configuration view showing a fixing member constituting the heating unit in the fixing device according to the first embodiment, and is a side view of the fixing member as viewed from the side opposite to the heating member side. FIG. 6 is a schematic configuration view showing a fixing member that constitutes the heating unit in the fixing device according to the first embodiment, and is a cross-sectional view taken along the line A-A shown in FIG. 5. FIG. 5 is a schematic view schematically showing a heat generation area of a heating member in the fixing device according to the first embodiment. FIG. 7A is an illustration showing a first step, and FIG. 8B is a diagram showing a second step. FIG. FIG. 7A is an explanatory view for explaining the difference in temperature uniformity depending on the direction of current flow to the heat generating layer in the fixing device according to the first embodiment, wherein (a) is a pair of power feeding electrodes for powering the heat generating layer in the longitudinal direction; It is a schematic block diagram which shows the electricity_supply structure of, and (b) is a graph which shows the temperature distribution in the longitudinal direction of a heat-generating layer when electrically supplying a heat-emitting layer to a longitudinal direction by a pair of feed electrode. FIG. 7A is an explanatory view for explaining the difference in temperature uniformity depending on the direction of current flow to the heat generating layer in the fixing device according to the first embodiment, wherein (a) is a pair of power feeding electrodes that apply current to the heat generating layer in the circumferential direction; It is a schematic block diagram which shows the electricity_supply structure of, and (b) is a graph which shows the temperature distribution in the longitudinal direction of a heat-generating layer when electrically supplying a heat-emitting layer to a circumferential direction by a pair of feed 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 inside. FIG. 14 is a schematic configuration view showing a fixing member constituting the heating unit in the fixing device according to the second embodiment, and is a side view of the fixing member as viewed from the heating member side. FIG. 14 is a schematic configuration view showing a fixing member constituting the heating unit in the fixing device according to the second embodiment, and is a side view of the fixing member as viewed from the side opposite to the heating member side. FIG. 14 is a schematic configuration view showing a fixing member constituting the heating unit in the fixing device according to the second embodiment, wherein (a) is a cross-sectional view along the line B-B shown in FIG. 13, (b) FIG. 14 is a cross-sectional view taken along the line C-C shown in FIG. FIG. 7 is a schematic view schematically showing a heat generation area of a heating member in a fixing device according to a second embodiment. FIG. 14 is a view showing a schematic configuration of a fixing member constituting the heating unit in the fixing device according to the third embodiment, and is a side view of the fixing member as viewed from the heating member side. FIG. 16 is a view showing a schematic configuration of a fixing member constituting the heating unit in the fixing device according to the third embodiment, and is a side view of the fixing member as viewed from the side opposite to the heating member side. FIG. 18 is a view showing a schematic configuration of a fixing member that constitutes a heating unit in the fixing device according to the third embodiment, and is a cross-sectional view taken along the line D-D shown in FIG. 17. FIG. 14 is a schematic view 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 an image forming apparatus 100 according to an 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 provided with a fixing device 15 according to an embodiment of the present invention.

  As shown in FIG. 1, the image forming apparatus 100 of this embodiment is a so-called tandem type color image forming apparatus in which a plurality of image carriers are arranged in parallel 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 the present embodiment, the fixing device 15 is applied to a tandem-type color image forming apparatus, but may be applied to other color image forming apparatuses. Although the fixing device 15 is applied to a color image forming apparatus, it may be applied to a monochrome image forming apparatus.

  The image forming apparatus 100 is an electrophotographic image forming apparatus, and a plurality of (four in this example) image forming units pa, pb, pc, and pd, an exposure unit 10, and a plurality (four in this example) primary order Recording material containing a recording material P such as transfer units 13a, 13b, 13c, 13d, intermediate transfer belt 11, waste toner box unit 12, secondary transfer unit 14, fixing device 15 (in this example, fixing unit), recording paper A storage unit (specifically, the internal sheet feeding unit 16 and the manual sheet feeding 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. The charging devices 103a, 103b, 103c and 103d and the developing units 102a and 102b are respectively provided around a plurality of (four in this example) photosensitive members 101a, 101b, 101c and 101d (specifically, photosensitive drums) that operate. , 102c and 102d and the cleaning units 104a, 104b, 104c and 104d are arranged in this order.

  In the image forming units pa, pb, pc, and pd, toners of respective colors of yellow (Y), magenta (M), cyan (C), and black (B) are accommodated, and yellow (Y) and magenta Toner images of the respective colors (M), cyan (C), and black (B) are formed on the photosensitive members 101a, 101b, 101c, and 101d, respectively. Further, primary transfer units 13a, 13b, 13c and 13d are disposed via the intermediate transfer belt 11 corresponding to the photosensitive members 101a, 101b, 101c and 101d.

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

  The primary transfer units 13a, 13b, 13c and 13d respectively overlap and 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 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 are not transferred to the intermediate transfer belt 11 by the primary transfer units 13a, 13b, 13c, and 13d, respectively, and the residual toners remaining on the surfaces of the photosensitive members 101a, 101b, 101c, and 101d, respectively. 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, 13d onto the recording material P, and the toner image 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 11 a and a driven roller 11 b. The secondary transfer unit 14 is disposed on the drive roller 11 a side of the intermediate transfer belt 11, and the 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 rotationally driven in the directions of arrows (in FIG. 1, counterclockwise) of four light beams (specifically, laser beams) from a light source unit 4 including a polygon mirror. It is configured to scan on the surface of 101b, 101c and 101d in the main scanning direction (rotational axis direction of the photosensitive member). Specifically, the exposure unit 10 is a light source unit for each beam modulated based on image data of yellow (Y) component, magenta (M) component, cyan (C) component and black (B) component input from the outside. Photosensitive members 101a, 101b, 101c, 101c, and 101d are led from the light source 4 and guided to photosensitive members 101a, 101b, 101c, and 101d by mirrors 8 to 8 and uniformly charged by charging devices 103a, 103b, 103c, and 103d. Each of 101d is exposed to light to form electrostatic latent images on the surfaces of the photosensitive members 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 more 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, the photosensitive members 101a, 101b, 101c, and 101d are uniformly charged by the charging devices 103a, 103b, 103c, and 103d, respectively, to form an image. 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 photosensitive members 101a, 101b, 101c, and 101d, respectively. Here, as the charging devices 103a, 103b, 103c, and 103d, in this example, charging rollers are used to uniformly charge the surfaces of the photosensitive members 101a, 101b, 101c, and 101d without generating ozone as much as possible. The system is adopted.

  Thereafter, in the image forming apparatus 100, electrostatic latent images formed on the photosensitive members 101a, 101b, 101c, and 101d are developed by the developing units 102a, 102b, 102c, and 102d, and visualized as toner images, respectively. 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 reverse polarity to that of the toner is applied, respectively. Form a 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 intermediately transferred. The sheet is conveyed to the secondary transfer unit 14 by the belt 11. On the other hand, the recording material P which has been pulled out from the sheet feeding roller 16a of the internal sheet feeding unit 16 or the sheet feeding roller 17a of the manual sheet feeding unit 17 toward the conveying path F and conveyed through the conveying path F is conveyed The toner image is conveyed by the registration roller 19 to the secondary transfer unit 14 in synchronization with the toner image on the intermediate transfer belt 11. 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 reverse polarity to that of the toner is applied. Transcribe.

  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 pressed to overlie the recording material. The recording material P on which the toner image is 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 is completed.

  Further, the transport path F is provided with a reversing path Fr for guiding 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 is reversed. When image formation is performed not only on the front surface of the recording material P but also on the back surface, the image forming apparatus 100 conveys the recording material P from the discharge roller 18a in the reverse direction to the reverse path Fr to reverse the front and back of the recording material P The toner image is formed on the back surface of the recording material P and fixed as in the case of the front surface of the recording material P, and then discharged outside the image forming apparatus 100 to the discharge tray 18. Place it.

[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 a power supply 43 electrically connected to the heating unit 33.

  As shown in FIG. 2, the fixing device 15 is stretched by a fixing member (specifically, the fixing roller 30), the heating member 40, the fixing roller 30 and the heating member 40, and one side in the circumferential direction V The endless fixing belt 32 which is heated by the heating member 40 while moving in the direction V1 of the sheet, and the pressure contact with the fixing roller 30 via the fixing belt 32, and the pressure contact with the fixing roller 30 via the fixing belt 32 And a pressure member (specifically, pressure roller 31) for forming the fixing nip portion N together with the fixing belt 32 in the image forming section, and an unfixed image on the recording material P passing the fixing nip portion N (specifically, The unfixed toner image T) is fixed to the recording material P.

  Specifically, the fixing device 15 heats and melts the toner image T when the recording material P on which the unfixed toner image T is formed in the fixing nip N passes through the fixing nip N, and the toner image on the recording material P Establish T. When the recording material P passes through the fixing nip N, the fixing belt 32 contacts 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 Contacts the opposite side.

  The fixing device 15 is disposed downstream 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) that is convexly curved toward the fixing belt 32 side. That is, the fixing device 15 is a sheet using a heating member 40 having a heating portion 40a1 (having a curved surface) which is convexly curved toward the fixing belt 32 as a heating means for heating the toner image T on the recording material P. It is considered as a fixing device of a heat generating belt fixing type.

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

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

  Specifically, the heating portion 40a1 of the holding member 40a has an arc shape that protrudes toward the fixing belt 32 as viewed from the front side (the rotation axis direction of the fixing roller 30). Here, the term “arc-like” is a concept including an arc-like shape that constitutes a part of a circular shape, and an elliptical arc-like shape that constitutes a part of an elliptical shape. In this example, the arc is an arc. The heating unit 33 including the heating member 40 including the holding member 40 a having the arc-shaped heating portion 40 a 1 and the fixing member 41 fixing the both sides in the circumferential direction V of the heating member 40 is a bow as viewed from the front side. It is shaped like a circle.

  The heat generating layer 40d is integrally formed on the inner circumferential surface of the heating portion 40a1 of the holding member 40a.

  In the holding member 40a, the fixing member 41 is located at both ends 40f and 40f in the circumferential direction V of the heating portion 40a1 or in the vicinity of the both ends 40f and 40f (a predetermined distance away from both ends 40f and 40f Fix the 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 operates a temperature sensor (thermisters 35A and 35B in this example) acting as a temperature detection unit for detecting the surface temperature of the fixing belt 32, and a predetermined electric power to the heat generating layer 40d of the heating member 40. The power supply 43 is further provided. The thermistors 35A and 35B are electrically connected to the input system of the control device 20. The temperature sensor is adapted to detect at least the surface temperature of the central portion in the direction along the surface of the fixing belt 32 (the rotation axis direction of the fixing roller 30) orthogonal to the circumferential direction V of the fixing belt 32. In this example, the thermistor 35A is provided at the center of the fixing roller 30 in the rotational axis direction of the fixing roller 30, and the thermistor 35B is provided without contact with the fixing belt 32 at one end (front side or back side).

  In the power supply 43, the power supply system is electrically connected to the heat generating layer 40 d, and the signal system is electrically connected to the output system of the control device 20. Then, based on detection signals from the thermistors 35A and 35B, the control device 20 performs operation control of the power supply 43 so that the temperature at the fixing nip N is maintained at a predetermined temperature (for example, fixing temperature). The configuration is such that the current-carrying state of the heat generating layer 40d is controlled. In the present embodiment, the pressure roller 31 is not provided with a heating means for heating the pressure roller 31. Therefore, the fixing device 15 is a temperature detection means for detecting the surface temperature of the pressure roller 31. Although not necessarily provided, in this example, a temperature sensor (thermistor 35C in this example) for detecting the surface temperature of the pressure roller 31 is preliminarily provided. Specifically, a thermistor 35 </ b> C is provided at the central portion of the pressure roller 31 in the rotational axis direction without contacting the pressure roller 31. The control device 20 not only detects the surface temperature of the fixing belt 32 detected by the detection result of the thermistors 35A and 35B, but also the surface temperature of the pressure roller 31 detected by the detection result of the thermistor 35C (for example, the surface temperature of the pressure roller 31 is The temperature of the fixing nip N can be controlled in consideration of whether or not the predetermined temperature is reached, and therefore, the temperature of the fixing nip N can be more accurately controlled. The temperature sensors used in this example are all noncontact types, but may be contact types.

  The fixing roller 30 and the pressure roller 31 are brought into pressure contact with each other with a predetermined load (for example, 392 N) via the fixing belt 32, and the fixing belt 32 and the pressure roller 31 are interposed between the fixing belt 32 and the pressure roller 31. The fixing nip portion N is formed at the pressure-contacting portion where the two 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 rotationally driven in a predetermined direction R so that the outer peripheral surface 30 c 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 the frictional resistance with the surface 32a.

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

  As the pressure roller 31, for example, one having a three-layer structure in which a cored bar 31a, an elastic layer 31b, and a release layer 31c are sequentially formed from the inside can be used. For the metal core 31a, for example, a material such as a metal such as iron, stainless steel, aluminum, copper or an alloy thereof can be used. Further, for the elastic layer 31b, for example, a rubber material having heat resistance and capable of elastic deformation, such as silicone rubber and fluororubber, can be suitably used. Further, for the release layer 31c, for example, a fluorine resin such as PFA (copolymer of tetrafluoroethylene and perfluoroalkylvinylether) or PTFE (polytetrafluoroethylene) can be suitably used. In this example, the pressure roller 31 has a diameter of about 30 mm, and the core metal 31 a is made of an iron alloy (carbon steel pipe for machine structure: STKM) having a diameter of 28 mm and a thickness of 1 mm. The layer 31 b is made of silicon solid rubber having a thickness of 1 mm, and the releasing layer 31 c is made of a PFA tube having a thickness of 30 μm. However, the configuration of the pressure roller 31, the material of the pressure roller 31, and the dimensions of the components constituting the pressure roller 31 are not limited to those.

  The fixing belt 32 is stretched so as to apply a tension between the heating member 40 of the heating unit 33 and the fixing roller 30 at a predetermined pressure. The fixing belt 32 is heated to a predetermined temperature by the 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. It is a thing.

  When the fixing roller 30 rotates, the fixing belt 32 moves in the direction V1 on one side of the circumferential direction V while being in sliding contact with the heating portion 40a1 of the heating member 40 in accordance with the fixing roller 30.

  For example, although not shown, the fixing belt 32 may have a three-layer structure in which an elastic layer is formed on the surface of a hollow cylindrical substrate and a release layer is formed on the surface. 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 of stainless steel, nickel or the like can be used. As the elastic layer, for example, an elastomer material (for example, silicone 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) excellent in heat resistance and releasability. Fluororesins, 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 using a heat-resistant resin such as polyimide as the base material, a fluorine resin may be internally added. Thus, by internally adding the fluorine resin to the base material of the heat resistant resin, it is possible to further reduce the frictional resistance with the heating unit 40a1 in the heating member 40, and thus reduce the sliding load with the heating unit 40a1. It can be done. In this example, the fixing belt 32 has a diameter of 37 mm when formed into a circular shape, the base material is made of polyimide having a thickness of 50 μm, the elastic layer is made of silicone rubber having a thickness of 150 μm, The mold layer consists of a 20 μm thick PFA tube. However, the configuration of the fixing belt 32, the material of the fixing belt 32, and the dimensions of the components constituting the fixing belt 32 are not limited to those. For example, the release layer may be not only a PFA tube but also coated with PFA, PTFE or the like.

  Here, as shown in FIG. 2, the heating unit 33 is disposed so as to be close to the entrance side of the fixing nip portion N in the conveyance direction W of the recording material P. In other words, the heating unit 33 is disposed on the upstream side (the inlet side of the fixing nip N) of the fixing nip N in the conveyance direction W of the recording material P. Specifically, the heating unit 33 has a second virtual straight line β passing through the fixing roller 30 and the heating member 40 with respect to the first virtual straight line α passing through the fixing roller 30 and the pressure roller 31. It is disposed on the upstream side (the inlet side of the fixing nip N) of the fixing nip N in W so as to be inclined at a predetermined inclination angle θ determined in advance. Specifically, the first virtual straight line α is a virtual straight line along the direction (vertical direction in this example) connecting the rotation center of the fixing roller 30 and the rotation center of the pressure roller 31, and the second virtual straight line β is a virtual straight line along a direction connecting the rotation center of the fixing roller 30 and the central portion of the heating unit 40 a 1 in the circumferential direction V of the heating member 40. The reason for arranging the heating unit 33 so as to be close to the entrance side of the fixing nip portion N in the conveyance direction W of the recording material P as described above will be described below.

  That is, the heating unit 33 is disposed on the opposite side of the fixing nip N with the rotational center of the fixing roller 30 or near the exit of the fixing nip N with respect to the conveyance direction W of the recording material P. In the case where the heating unit 33 is disposed, in other words, when the heating unit 33 is disposed on the downstream side of the fixing nip portion N (outlet side of the fixing nip portion N) in the conveyance direction W of the recording material P, the fixing nip portion N Since the fixing angle of the fixing belt 32 with respect to the fixing roller 30 after leaving the fixing roller 30 becomes small, the fixing belt 32 driven by the fixing roller 30 is easily floated from the fixing roller 30 immediately after leaving the fixing nip portion N. As described above, when the fixing belt 32 floats 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 peeling property of the recording material P may be inhibited. is there. From this, the heating unit 33 is closer to the entrance side of the fixing nip N in the conveyance direction W of the recording material P, in other words, upstream of the fixing nip N in the conveyance direction W of the recording material P. It is preferable to arrange so as to be inclined to the side (the inlet side of the fixing nip portion N). In this example, the inclination angle θ at which the heating unit 33 is inclined is, although not limited thereto, 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 supply 43 electrically connected to the heating unit 33. As shown in FIG. FIG. 4 is a schematic configuration view showing a heating member 40 constituting the heating unit 33 in the fixing device 15 according to the first embodiment. FIG. 4A is a front view of the heating member 40 as viewed from the front side, and FIG. 4B is a side view of the heating member 40 as viewed from the inside. 5 to 7 are schematic configuration diagrams showing the fixing member 41 constituting the heating unit 33 in the fixing device 15 according to the first embodiment. 5 is a side view of the fixing member 41 as viewed from the heating member 40 side, and FIG. 6 is a side view of the fixing member 41 as viewed from the side opposite to the heating member 40 side. It is sectional drawing along the AA shown to these.

  The heating member 40 and the fixing member 41 (see FIG. 3) constituting the heating unit 33 are in the longitudinal direction D (the rotation axis direction of the fixing roller 30) which is a direction along the surface of the fixing belt 32 orthogonal to the circumferential direction V. It extends. The heat generating layer 40d is formed entirely or substantially entirely in the heating region of the heating unit 40a1. In this example, the heat-generating layer 40d is a heating portion of the inner circumferential surface of the heating portion 40a1 except predetermined predetermined regions (specifically, regions in which feeding layers 40c1 and 40c2 described later are provided) at both ends in the circumferential direction V It is entirely formed in the area. Here, the heating area is an area corresponding to the area for heating the recording material P as much as possible.

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

  The pair of feed electrodes 42a and 42b are 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) It is provided at a predetermined distance predetermined inward from both end portions).

  Further, at least one of the pair of feed electrodes 42a and 42b for energizing the heat generating layer 40d in the circumferential direction V (one in this example) (in this example, one feed electrode 42a (1) to 42a (in this example) n)) (refer to FIG. 6) are provided electrically independently of each other with respect to the longitudinal direction D of the fixing member 41 (direction along the surface of the recording material P orthogonal to the conveyance direction W of the recording material P) There is. Here, n is an integer of 2 or more. In this example, n is eight.

  Of the pair of feed electrodes 42a and 42b for energizing the heat generating layer 40d in the circumferential direction V, only one of the feed electrodes (in this example, 42a) is electrically independent of each other in the longitudinal direction D of the fixing member 41 When provided, the following aspect can be illustrated.

  That is, any other feed electrode (42b in this example) is electrically integrated, and the tip of the other feed electrode (42b in this example), specifically, the feed layer (40c2 in this example) Or a portion in contact with the heat generating layer 40d of the other feed electrode (in this example, 42b) when the feed layer is not provided, to the one feed electrode (in this example, 42a). It is an aspect divided corresponding to a longitudinal direction D in plurality. By so doing, current can be made to easily flow in the circumferential direction V in the heat generating layer 40 d, and individual heat generating regions in the heat generating layer 40 d can be clarified. In this case, the feed layer (for example, 40c2) corresponding to the other feed electrode (for example 42b) is electrically divided at the boundary between the other adjacent feed electrodes, or the feed layer is not provided. In this case, a slit is provided at the boundary between the other adjacent feed electrodes of the end corresponding to the other feed electrode (for example, 42b) among the two ends in the circumferential direction V of the heat generating layer 40d. preferable. By doing this, individual heat generation regions in the heat generation layer 40d can be made more clear.

  Further, only one of the pair of feed electrodes 42a and 42b (in this example, 42a in this example) for electrically energizing the heat generating layer 40d in the circumferential direction V is electrically independent of each other in the longitudinal direction D of the fixing member 41. In the case where a plurality of switches are provided, the following mode may be adopted.

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

  Also, the feed layer (40c1 in this example) corresponding to the plurality of electrically independent feed electrodes (in this example, 42a) is electrically divided at the boundary between the adjacent feed electrodes. When the feed layer is not provided, it corresponds to the feed electrode (42a in this example) on the side provided with a plurality of electrically independent ones of both end portions in the circumferential direction V of the heat generating layer 40d. It is possible to illustrate an embodiment in which a slit is provided at the boundary between the adjacent feed electrodes of the end portion. By so doing, current can be more easily flowed in the circumferential direction V in the heat generating layer 40d, and individual heat generating regions in the heat generating layer 40d can be made clearer.

  Specifically, the heating unit 33 heats the fixing belt 32 with the heating unit 40 a 1 of the heating member 40 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 feeding electrodes 42a and 42b, and a power supply 43 for supplying predetermined power to the heat generating layer 40d of the heating member 40 supplies a pair of feedings. The electrodes 42a and 42b are electrically connected.

  As shown in FIGS. 3 and 4, the heating member 40 is a multilayer including a heating portion 40a1, a first insulating layer 40b1, a pair of feed layers 40c1 and 40c2, a heat generating layer 40d, and a second insulating layer 40b2. It has a configuration.

  In this example, the first insulating layer 40b1 is integrally formed entirely in the heating region of the inner peripheral surface of the heating portion 40a1. The pair of feed layers 40c1 and 40c2 is inside the first insulating layer 40b1 by a predetermined distance (the distance of providing the pair of feed layers 40c1 and 40c2) from both ends in the circumferential direction V in the circumferential direction V, and In the longitudinal direction D, the entire area is integrally formed. The heat generating layer 40 d is in electrical contact with the pair of feed layers 40 c 1 and 40 c 2 between the pair of feed layers 40 c 1 and 40 c 2 in the circumferential direction V on the first insulating layer 40 b 1 and in the longitudinal direction D Are integrally formed. The second insulating layer 40b2 is integrally formed on the entire heat generating layer 40d. In place of the pair of feed layers 40c1 and 40c2, the heat generating layer 40d may be integrally formed on the entire surface of 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 the both ends of the heating portion 40a1 in the circumferential direction V toward the fixing roller 30 (FIGS. 3 and 4A). See). The holding member 40a has a structure in which the heating portion 40a1 and the pair of skirt portions 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 symmetrical shape based on 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 imaginary straight line β. That is, the heating member 40 has a semicylindrical 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 lateral direction C) = 23 mm, and a height H1 (normal The size of the direction E) is 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 on the surface of the holding member 40a (at least the contact surface of the heating unit 40a1 with the fixing belt 32), fluorine resin such as PFA or PTFE is used to suppress abrasion of the fixing belt 32 due to rubbing with the fixing belt 32. May be coated.

  First, the first insulating layer 40b1 is integrally laminated on the surface (rear surface) opposite to the contact surface with the fixing belt 32 of the heating portion 40a1 in the holding member 40a. The first insulating layer 40b1 is provided to insulate the conductive holding member 40a so that the heat generating layer 40d does not electrically leak. 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 thereto, and any insulating material can be used for the first insulating layer 40b1.

  Next, on the first insulating layer 40b1, the heat generating layer 40d is integrally formed inward by a predetermined distance (the distance for providing the pair of feed layers 40c1 and 40c2) from both end faces in the circumferential direction V of the heat generating layer 40d. It is stacked. As the heat generating layer 40d, any material can be used as long as it is an electric resistance material having heat resistance and having a predetermined electric resistance value for generating heat by Joule heat, for example, silver palladium or polyimide An electric resistance material such as one obtained by mixing a conductive filler in a heat resistant resin such as, etc. can be used. In this example, the heat generating layer 40d is made of conductive polyimide having a thickness of 50 μm.

  Further, a pair of feed layers 40c1 and 40c2 are integrally stacked on both outer sides in the circumferential direction V of the heat generating layer 40d on the first insulating layer 40b1. The end faces of the pair of feed layers 40c1 and 40c2 in the circumferential direction V on the side of the heat generating layer 40d are electrically in contact with both end faces of the heat generating layer 40d in the circumferential direction V, respectively. The electric resistances of the pair of feed 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, a paste-like composition containing a conductive material can be suitably used as the material of the pair of feed layers 40c1 and 40c2. In this example, the pair of feed layers 40c1 and 40c2 are made of silver paste having a thickness of 50 μm.

  In the present embodiment, at least one (one in this example) of the pair of feeding electrodes 42a and 42b (one feeding electrode 42a (1) to 42a (n) in this example) is the feeding electrode. In the longitudinal direction D of the fixing member 41, a plurality of electrodes are provided independently of each other electrically, but even if a plurality of feed electrodes are provided independently of each other in this manner, the heating member 40 electrically If the conduction directions of the plurality of feed electrodes provided independently of one another are not configured to be directed in the circumferential direction V, a current flows in the longitudinal direction D in the heat generating layer 40d and flows in the entire heat generating layer 40d. Cheap.

  Therefore, in the heating member 40, the conduction directions of the plurality of feed electrodes electrically provided mutually independently (in this example, one feed electrode 42a (1) to 42a (n) electrically independent of n) Are provided in the circumferential direction V respectively.

  For example, the feed layer corresponding to the plurality of feed electrodes provided on the side which are electrically independent (in this example, n feed electrodes 42a (1) to 42a (n) electrically independent of n) Of the two end portions of the heat generating layer 40d in the circumferential direction V, when it is electrically divided at the boundary between one of the adjacent feed electrodes 42a and 42a, or when the pair of feed layers 40c1 and 40c2 is not provided. And one of the end portions corresponding to the plurality of electrically independent power supply electrodes (in this example, n electrically independent power supply electrodes 42a (1) to 42a (n)). The slits are provided at the boundary between the adjacent feed electrodes 42a and 42a, so that the current can be more easily flowed 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 feed layer 40c1 (refer to the upper side in FIG. 4) serves as a conduction guide portion, and feeds one adjacent feed in one feed electrode 42a to 42a provided in the longitudinal direction D independently and electrically. A space S (specifically, a space S1) having a predetermined distance for electrical insulation is provided at a portion corresponding to the electrodes 42a and 42a and is electrically separated.

  Next, the second insulating layer 40b2 is integrally laminated on the heat generating layer 40d. In the second insulating layer 40b2, when an unnecessary substance such as a foreign matter intrudes into the heating unit 33 and comes into contact with the heat generating layer 40d, the heat generating layer 40d may electrically leak or the heat generating layer 40d may be constantly exposed to the atmosphere. It is provided for the purpose of effectively preventing the heat generating layer 40d from being deteriorated by being exposed. In this example, the second insulating layer 40b2 is made of polyimide having a thickness of 30 μm. However, the invention is not limited thereto, and any insulating material can be used for the second insulating layer 40b2 as in the case of the first insulating layer 40b1.

  In addition to fixing the fixing member 41 across the heating member 40 in the circumferential direction V (a pair of skirts 40a 2 and 40a 3 in this example), the heating member 40 is fixed to the inner circumferential surface 32a of the fixing belt 32. And the pair of feed electrodes 42a and 42b for energizing the heat generating layer 40d.

  As described above, the holding member 40 a constituting the heating member 40 is made of an aluminum material having a thickness of 0.3 mm, and the mechanical strength of the heating unit 33 is low only by the heating member 40. Although the inner peripheral surface 32a can not be pressed 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 heating unit The mechanical strength 33 can be improved, and the heating member 40 can be pressed against the inner circumferential surface 32 a of the fixing belt 32 with a sufficient load (pressure).

  In the present embodiment, the pressing load of the heating member 40 in the heating unit 33 with respect to the fixing belt 32 is 39.2N. For the fixing member 41, for example, a thermosetting resin such as Bakelite, a PPS (polyphenylene sulfide) resin, a heat resistant resin such as 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 thermal insulation (low thermal conductivity) compared to metals, so the heat generated by the heating member 40 is less likely 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 formed of a long member (in this example, a substantially hexahedral block body) elongated in the longitudinal direction D. The fixing member 41 has a pair of feed electrodes 42a and 42b attached to both ends in the short direction C or in the vicinity of the 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 lateral direction C) = 22 mm, and a height H2 (The size in the normal direction E) = 4.2 mm, and a liquid crystal polymer is used as a material of the fixing member 41.

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

  The pair of feed patterns 44, 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 to the pair of feed electrodes 42a, 42b. And the terminal portions 44a and 45a electrically connected to the power supply 43 side, and the line portions 44b and 45b electrically connecting the terminal portions 44a and 45a and the pair of feed 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, and in terms of facilitating the connection of the cable wiring from the power supply 43, the width is larger than the width of the line portions 44b and 45b. It is getting wider. The pair of feed patterns 44 and 45 can be formed of an electrically conductive material by any forming method, but in this example, after a copper plate is attached to the entire surface of the lower surface 41 b of the fixing member 41, the etching process is performed. It is supposed that it forms in a predetermined pattern by giving.

  One of the feed patterns 44 of the pair of feed patterns 44 and 45 is electrically provided independently on the lower surface 41 b of the fixing member 41 on one side (right side in FIG. 6) than the central portion in the longitudinal direction D. One of the feed electrodes 42a to 42a is formed along the longitudinal direction D from an end on one side in the longitudinal direction D, and is electrically connected to the one feed electrode 42a to 42a on one side. And one end of the other side in the longitudinal direction D for one of the feed electrodes 42a to 42a provided on the other side (left side in FIG. 6) of the central portion in the longitudinal direction D independently of each other electrically. It is formed along the longitudinal direction D from the part and is electrically connected to one of the feed electrodes 42 a to 42 a on the other side.

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

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

  Each of the pair of feed electrodes 42a and 42b is a metal plate having elasticity (spring). Thus, the pair of feed electrodes 42a and 42b are both metal plates having elasticity (springiness), and the elasticity (springiness) of the metal plate causes the pair of feed layers at a predetermined pressure. It can be made to abut on 40c1 and 40c2 reliably. Further, the pair of feed electrodes 42a and 42b, both in contact with the pair of feed layers 40c1 and 40c2 in the heating member 40, protrude from the upper surface 41a of the fixed member 41, and free ends 42a1 and 42b1 (see FIG. 7) Is bent in an L-shape or a substantially L-shape inside in the lateral direction C, and is formed to incline toward the inside in the lateral direction C. In this manner, in the pair of feed electrodes 42a and 42b, the free end portions 42a1 and 42b1 bend inward in the L direction or L shape in the lateral direction C and toward the inside in the lateral direction C. By being formed to be inclined, the pair of feed layers 40c1 and 40c2 can be stably brought into contact with each other.

  In addition, the pair of feed electrodes 42a and 42b are divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41 (specifically, the heating member 40 side of the lower surface 41b of the fixing member 41) (see FIG. 5) ). In this example, the individual feed electrodes 42a (1) to 42a (n) which are electrically independent at one feed electrode 42a are divided into a plurality of parts (specifically, two), and the entire feed electrode 42a is entirely It is divided into multiples of n (specifically, 16 divisions of twice n = 8), and the other feed electrode 42b is divided into the same number as the number of divisions of one feed electrode 42a (specifically, 16) It is divided.

  In other words, as shown in FIG. 6, at least one of the pair of feed electrodes 42 a and 42 b (in this example, one feed electrode 42 a) is an individual feed electrode divided on the upper surface 41 a side of the fixing member 41. A plurality of (two in this example) adjacent to each other are integrated on the lower surface 41 b side of the fixing member 41. In this example, in the other feed electrode 42 b of the pair of feed electrodes 42 a and 42 b, the feed electrodes divided on the upper surface 41 a side of the fixing member 41 are all integrated on the lower surface 41 b side of the fixing member 41. Therefore, one feed electrode 42a is electrically independent of n (specifically, eight), and the free ends of the respective independent feed electrodes 42a (1) to 42a (n) are electrically independent. Each of the portions 42a1 is divided into a plurality of parts (specifically, divided into two), and the other feed electrode 42b is electrically provided integrally and the free end 42b1 is divided into a multiple of n (specifically, Divided into 16).

  Thus, the pair of feed electrodes 42a and 42b are divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41 (specifically, the heating member 40 side of the lower surface 41b of the fixing member 41), As compared with the case of the integral shape which is not divided, it is possible to contact the pair of feed layers 40c1 and 40c2 more stably. In the present embodiment, the feed layer (in this example, one feed layer 40c1) (see the upper side in FIG. 4) corresponds to a portion between the feed electrodes 42a divided into a plurality (specifically, two). A space S (specifically, a space S2) of a predetermined distance is provided at a portion to be electrically separated.

  The side of the pair of feed electrodes 42a and 42b in electrical contact with the pair of feed patterns 44 and 45 is, as shown in FIG. The surfaces 42a2 and 42b2 opposite to the fixing member 41 in the portion are fixed to the fixing member 41 so as to be in close contact with the lower surface 41b of the fixing member 41.

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

  As described above, by forming the pair of feed electrodes 42a and 42b and the pair of feed patterns 44 and 45, n (eight in this example) regions to be energized in the longitudinal direction D independently in the heat generating layer 40d are formed. It is possible to generate heat.

  FIG. 8 is a schematic view 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 is shown in which all the regions corresponding to one of the feed electrodes 42 a (1) to 42 a (n) of the heat generating layer 40 d are energized.

  As shown in FIG. 8, in the fixing device 15 according to the first embodiment, since the other feeding electrode 42b side is electrically integrated, the heat generation area of the heating unit 40a1 is electrically independent. One of the feed layers 40c1 to 40c1 electrically connected to the provided feed electrodes 42a (1) to 42a (n) and electrically separated at a predetermined interval S (specifically, the space S1). It has a trapezoidal shape that is slightly expanded outward toward the other integrated feed layer 40c2 side electrically connected to the other feed electrode 42b from the 40c1 side, but there is no particular problem in practical use, and heat generation area control The number of heat generating regions can be increased while the shape of the other feed pattern 45 (see FIG. 6) is simplified by electrically integrating the other feed electrode 42b side. It becomes possible.

  Note that the temperature detection sensor is not limited to at least one heat generation area of the plurality of heat generation areas in the longitudinal direction D of the heating unit 40a1 (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). (Heat generation area where the recording material P can be heated), for example, in the case where the recording material P is conveyed on the basis of the center, the surface temperature of the fixing belt 32 corresponding to at least the heat generation area at the center is detected be able to. For example, a plurality of temperature detection sensors can be provided corresponding to a plurality of heat generation areas in the longitudinal direction D of the heating unit 40a1. In this way, temperature control can be performed for each of the plurality of heat generation regions.

  Next, a method of manufacturing 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 of manufacturing the heating member 40 can be similarly described for the heating member 40 in the fixing device 15 according to the second and third embodiments described later.

  FIG. 9 is an explanatory view for explaining a method of manufacturing the heating member 40 in the fixing device 15. Fig.9 (a) is a figure which shows a 1st process, FIG.9 (b) is a figure which shows a 2nd process.

  In the method of manufacturing the heating member 40, the heat generating layer 40d is formed by laminating the first step (see FIG. 9A) of forming the flat heating member 40 by laminating the heat generating layer 40d and the first step. And a second step (see FIG. 9B) of processing the flat heating member 40 into a semicylindrical heating member 40 by predetermined bending (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 applied to the flat holding member 40a (specifically, a metal plate). 40d, a pair of feed layers 40c1 and 40c2 and a second insulating layer 40b2 are sequentially formed by a method such as screen printing. The heat generating layer 40d and the pair of feed layers 40c1 and 40c2 may be formed first, regardless of the order of formation of the heat generating layer 40d and the pair of feed layers 40c1 and 40c2.

  Next, after all the layers of the first insulating layer 40b1, the heat generating layer 40d, the pair of feeding layers 40c1 and 40c2, and the second insulating layer 40b2 are formed in the first step, in FIG. 9B, in the second step. As shown, a predetermined bending process (in this example, gold) of a flat holding member 40a in which the first insulating layer 40b1, the heat generating layer 40d, the pair of feeding layers 40c1 and 40c2, and the second insulating layer 40b2 are stacked is formed. By pressing using a mold F1, F2, it is processed into a semicylindrical shape (an arch shape as viewed from the front side).

  In addition, since stress is applied to each layer at the time of bending, as a material of each layer, it is more preferable to use a material having flexibility. 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. In addition, although silver paste is used for the pair of feed layers 40c1 and 40c2, since the width of the pair of feed layers 40c1 and 40c2 in the circumferential direction V is narrow, 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 (the heating unit 33 in this example) for heating the fixing belt 32 has a curved shape that is curved toward the fixing belt 32 side. Since the heating member 40 having the heating portion 40a1 of a shape and the fixing member 41 which bridges and fixes both sides in the circumferential direction V of the heating member 40 are included, both sides in the circumferential direction V of the heating member 40 are fixed members 41. 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 secured. As a result, the heating member 40 can be strongly pressed against the inner circumferential surface 32 a of the fixing belt 32, and as a result, the heating loss can be reduced to improve the heating efficiency.

  By the way, although the heating member 40 is made into a semi-bent shape in this example, when manufacturing this semi-bent shaped heating member 40, formation of the heat generating layer 40d (each layer containing the heat generating layer 40 d in this example) is formed. Bending into a semicylindrical shape in advance makes it difficult to form the heat generating layer 40d (each layer including the heat generating layer 40d in this example) thereon.

  In this respect, according to the method of manufacturing the heating member 40 according to the first embodiment, the first step of manufacturing the flat heating member 40 by laminating the heating layer 40d (in this example, each layer including the heating layer 40d). The flat heating member 40 in which the heating layers 40d (each layer including the heating layer 40d in this example) are stacked in the first step is bent by a predetermined bending process (pressing in this example). Specifically, the heat generating layer 40d (in this example, each layer including the heat generating layer 40d) is stacked on the flat holding member 40a to form the flat heating member 40. By bending the flat-plate-like heating member 40 after production, it is possible to easily process the multi-layered heating member 40 into a semicylindrical shape.

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

  Further, 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 the heat generating layer 40 d formed entirely or substantially entirely in the heating region of the heating unit 40 a 1, so that the conventional linear shape as described in Patent Documents 3 to 5 described above Alternatively, as compared with the belt-like heat generating layer, temperature unevenness on the surface of the heating member 40 can be suppressed, and the life extension of the heating member 40 can be realized.

  By the way, although a pair of feed electrodes 42a and 42b which feed electricity to exothermic layer 40d may be constituted so that electricity of exothermic layer 40d may be energized in the longitudinal direction D, in this case, the length required for energization of exothermic layer 40d is long. As a result, the temperature variation is likely to occur in the longitudinal direction D of the heating member 40 due to the influence of the heat variation due to the resistance variation of the heat generating layer 40d.

  Then, it is possible to make it hard to receive the influence of the heat generation nonuniformity by resistance variation of heat generation layer 40d, and it is desirable to control temperature nonuniformity in longitudinal direction D of heating member 40.

"Experimental example"
In this regard, in the fixing device 15 according to the first embodiment, the difference in temperature uniformity depending on the direction of current flow to the heat generating layer 40d was experimented, and therefore, it will be described below.

  FIGS. 10 and 11 are explanatory diagrams for explaining the difference in temperature uniformity depending on the direction of current flow to the heat generating layer 40 d in the fixing device 15 according to the first embodiment. FIG. 10 (a) is a schematic configuration diagram showing a conduction configuration of a pair of feed electrodes 42a, 42b for energizing the heat generating layer 40d in the longitudinal direction D, and FIG. 10 (b) is a view by the pair of feed electrodes 42a, 42b. It is a graph which shows 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. 11 (a) is a schematic diagram showing the current-carrying configuration of the pair of feed electrodes 42a and 42b for passing the heat generating layer 40d in the circumferential direction V, and FIG. 11 (b) is a pair of feed electrodes 42a, 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 same material is used regardless of the current flow direction as the heat generation layer 40d, and a pair of feed electrodes 42a and 42b are provided at both ends in the longitudinal direction D of the heat generation layer 40d (the current flow direction is the heat generation layer A longitudinal direction D of 40d is a first experimental example (see FIG. 10), and a pair of feed electrodes 42a and 42b are provided at both ends in the circumferential direction V of the heat generating layer 40d (the current flow direction is the circumferential direction of the heat generating layer 40d) V) was a second experimental example (see FIG. 11).

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

  As a result, as shown in FIG. 10 (b), while the temperature variation of about 8 degrees occurred in the first experimental example, as shown in FIG. 11 (b), about 3 degrees in the second embodiment. It was found that the temperature variation was within.

  From the above results, by energizing in the circumferential direction V of the heat generating layer 40d, it is possible to suppress the influence of the heat generation unevenness due to the resistance variation of the heat generating layer 40d, and 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 feed electrodes 42a and 42b for supplying power to the heat generating layer 40d are configured to energize the heat generating layer 40d in the circumferential direction V. As a result, it is possible to suppress the influence of the heat generation unevenness due to the resistance variation of the heat generating layer 40d because the length required for energization of the heat generating layer 40d is short, thereby making the temperature uniform in the longitudinal direction D of the heating member 40. It is possible to improve the quality.

  Further, the pair of feed electrodes 42 a and 42 b are provided at both ends of the fixing member 41 in the short direction C with respect to the fixing member 41 or in the vicinity of the both ends. The fixing configuration can be combined with the configuration for supporting the pair of feed electrodes 42a and 42b, and the configuration of the heating component (in this example, the heating unit 33) can be simplified accordingly.

  The fixing member 41 is configured to press the heating member 40 against the inner circumferential surface 32 a of the fixing belt 32, thereby fixing the heating member 40 of the fixing member 41 to the fixing belt 32. The configuration can also be combined with pressing the inner peripheral surface 32a of the second embodiment, and the configuration of the heating component (in this example, the heating unit 33) can be simplified accordingly.

  By the way, the temperature of the portion where the recording material P does not pass in the longitudinal direction D of the heating member 40 tends to rise as compared with the portion 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, in the conventional fixing device, the area on the recording material P where the image is not formed is also heated, and power is unnecessarily consumed.

  In this respect, in the first embodiment, at least one of the pair of feed electrodes 42a and 42b (in this example, one feed electrode 42a) for energizing the heat generating layer 40d in the circumferential direction V is the longitudinal direction of the fixing member 41. With regard to D, by providing a plurality of electrically independent ones, it is possible to provide a plurality of heat generation areas that are independently energized in the longitudinal direction D of the fixing member 41, whereby recording materials P of various sizes can be provided. And heat can be generated only in the area necessary for the image forming pattern, and abnormal temperature rise can be suppressed in the 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 a 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 a portion where the image is not formed in the recording material P by image data. It can be done.

  In the first embodiment, the heating members 40 are electrically connected to each other in a plurality of feed electrodes (in this example, the feed electrodes 42a (1) to 42a (n)). Conduction guide portion directed in the circumferential direction V (specifically, a space S1 which electrically divides at least one feed layer of the pair of feed layers 40c1 and 40c2, in this example, one feed layer 40c1 in the longitudinal direction D) Is provided to facilitate the flow of current in the circumferential direction V in the heat generating layer 40d, and reliably performs individual heat generation for each of the plurality of feed electrodes provided electrically independently in the longitudinal direction D. be able to.

  Further, in the first embodiment, the heating component (in this example, the heating unit 33) is disposed close to the entrance side of the fixing nip N with respect to 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 leaving the fixing nip portion N can be increased, thereby avoiding inhibition of the removability 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. 12 to 16.

  FIG. 12 is a schematic configuration view showing a heating member 40A constituting the heating unit 33 in the fixing device 15 according to the second embodiment. 12 (a) is a front view of the heating member 40A as viewed from the front side, and FIG. 12 (b) is a side view of the heating member 40A as viewed from the inside. 13 to 15 are schematic configuration diagrams showing a fixing member 41A that constitutes 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 as viewed from the heating member 40A side, and FIG. 14 is a side view of the fixing member 41A as viewed from the opposite side to the heating member 40A side. 13 is a cross-sectional view taken along the line B-B shown in FIG. 13, and FIG. 15 (b) is a cross-sectional view taken along the line C-C shown in FIG. 13.

  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, one of the feeding electrodes 42aa and 42ab, and one feeding pattern 44. The same reference numerals are given to members having the same configuration, and here, points different from the first embodiment will be mainly described.

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

  In this example, one feed layer 40c1 (see the upper side in FIG. 12) is adjacent to one of the feed electrodes 42aa to 42aa and 42ab to 42ab provided in the longitudinal direction D independently and electrically as a conduction guide. A space S (specifically, a space S1) of a predetermined distance for electrical insulation is provided at a portion corresponding to one of the matching feed electrodes 42aa and 42ab, and is electrically divided. The other feed layer 40c2 (see the lower side in FIG. 12) serves as a conduction guide portion between the other feed electrodes 42b and 42b adjacent to each other in the other feed electrodes 42b to 42b divided in the longitudinal direction D. A space S (specifically, a space S1) of a predetermined distance for electrical insulation is provided at a corresponding place and electrically separated.

  The fixing member 41A is, as shown in FIGS. 13 to 15, an elongated member (in this example, a substantially hexahedral block body) elongated in the longitudinal direction D. In the fixing member 41A, a pair of feed electrodes (42aa, 42ab) and 42b are attached to both ends in the lateral direction C or in the vicinity of the 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 lateral 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 a material of the fixing member 41A.

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

  One of the feed patterns 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 to one of the feed electrodes 42aa and 42ab. And a line portion 44b electrically connecting between the terminal portion 44a and one of the feed electrodes 42aa and 42ab.

  The terminal portions 44a are provided at both ends 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 the connection of the cable wiring from the power supply 43. .

  One of the feed patterns 44 is electrically independent on one of the feed electrodes 42ab to 42ab provided on the upper surface 41a of the fixed member 41A (on the left side in FIG. 13) than the central portion in the longitudinal direction D. On the other hand, each one is formed along the longitudinal direction D from the end on one side in the longitudinal direction D, is electrically connected to one of the feed electrodes 42ab to 42ab on the one side, and is electrically independent and longitudinal One feeding electrode 42ab to 42ab provided on the other side (right side in FIG. 13) of the central part in the direction D, one along the longitudinal direction D from the other end of the longitudinal direction D It is electrically connected to one of the feed electrodes 42ab to 42ab on the other side.

  Further, one feed pattern 44 is provided on one side (right side in FIG. 14) of the lower surface 41b of the fixing member 41A electrically independent on the one side (right side in FIG. 14) than the central portion in the longitudinal direction D. 42 aa are formed along the longitudinal direction D from one end of the longitudinal direction D one by one and electrically connected to one of the feed electrodes 42 aa to 42 aa on the one side, and electrically independent Along the longitudinal direction D from the other end of the longitudinal direction D, one for each of the feed electrodes 42aa to 42aa provided on the other side (left side in FIG. 14) than the central portion in the longitudinal direction D It is formed and electrically connected to one of the feed electrodes 42aa to 42aa on the other side.

  One of the feed electrodes 42aa and 42ab electrically connects one feed pattern 44 and one feed layer 40c1 of the heating member 40A, and is made of metal such as stainless steel or copper.

  One of the feed electrodes 42aa and 42ab is a metal plate having elasticity (spring). Thus, one of the feed electrodes 42aa and 42ab is a metal plate having elasticity (spring property), and the elasticity (spring property) of the metal plate causes one feed layer 40c1 to be applied at a predetermined pressure. It can be made to abut reliably. Further, one of the feed electrodes 42aa and 42ab is in contact with one feed layer 40c1 of the heating member 40A and protrudes from the upper surface 41a of the fixed member 41A, and the free end 42a1 (see FIG. 15) is in the short direction C It is formed so as to bend inward into an L-shape or a substantially L-shape and to incline toward the inside in the lateral direction C. Thus, one of the feed electrodes 42 aa, 42 ab is bent so that the free end 42 a 1 is L-shaped or substantially L-shaped inward in the latitudinal direction C and inclined inward in the latitudinal direction C. By being formed, one feed layer 40c1 can be stably abutted.

  Further, one of the feed 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, the heating member 40A side of the lower surface 41b of the fixing member 41A) (see FIG. 13). ). In this example, one of the feed electrodes 42aa and 42ab is divided into n (specifically, 16). Thus, one of the feed 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, the heating member 40A side of the lower surface 41b of the fixing member 41A), As compared with the case of the integral shape which is not divided, it becomes possible to contact the one feed layer 40c1 more stably.

  One feed electrode 42aa (1) to 42aa (n1) and one feed electrode 42ab (1) to 42ab (n2) are alternately provided on the fixed member 41A. The side in electrical contact with one feed pattern 44 of one of the feed electrodes 42aa (1) to 42aa (n1) provided alternately is located inside the short direction C, as shown in FIG. It is fixed to the fixing member 41A so that the surface 42a2 which is bent in an L-shape and faces the fixing member 41A of the bent L-shaped part is in close contact with the lower surface 41b of the fixing member 41A. Further, as shown in FIG. 15B, the side electrically contacting one of the feed patterns 44 of the other feed electrodes 42ab (1) to 42ab (n2) provided alternately is a short side direction C, as shown in FIG. It is fixed to the fixing member 41A so that the surface 42a3 which is bent at an acute angle inside and faces the fixing member 41A at the bent acute angle part is in close contact with the upper surface 41a of the fixing member 41A. The tip portion of (b) is bent parallel or substantially parallel to the short side direction C.

  Further, as shown in FIGS. 13 and 14, one of the feed electrodes 42aa and 42ab is electrically independent. Therefore, one of the feed electrodes 42aa and 42ab is electrically provided n (16 in this example) independently.

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

  As described above, by forming one of the feed electrodes 42aa and 42ab and one of the feed patterns 44, n regions n = n1 + n2 (16 in this example) to be energized independently in the longitudinal direction D in the heat generating layer 40d It is possible to generate heat. That is, since the feed 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, the longitudinal direction D of the heat generating layer 40d is made independent as compared with the first embodiment. It is possible to double the number of heat generation areas to be energized (16 in this example, twice the eight).

(About the second embodiment)
According to the fixing device 15 of the second embodiment, in addition to the functions and effects of the fixing device 15 of the first embodiment, a plurality of feed electrodes 42aa and 42ab provided electrically independently of each other on the power supply 43 side The feed pattern 44 that electrically connects the lines becomes wider (area becomes larger) in order to increase the current capacity, and the number of feed electrodes electrically independent (the space of the fixing member 41A provided with the feed pattern) Is provided on both sides with respect to the thickness direction of the fixing member 41A, rather than providing the feeding pattern 44 on one side in the thickness direction of the fixing member 41A as in the first embodiment, The number of electrically independent feed electrodes can be increased. In this example, compared to the first embodiment, it is possible to increase the number of heat generation areas to 16 times the heat generation area twice the eight heat generation areas in the longitudinal direction D of the fixing device 15.

  As a result, the temperature control of the heat generation area can be performed more finely for various sizes of the recording material P and the image formation pattern, and the 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 as well as the effect of suppressing unnecessary heating in the area where image formation is not performed can be further improved, which can contribute to energy saving.

  FIG. 16 is a schematic view schematically showing a heat generation area of the heating member 40A in the fixing device 15 according to the second embodiment. The example shown in FIG. 16 shows a state in which all the regions corresponding to one of the feed 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, both the one feeding layer 40c1 and the other feeding layer 40c2 are provided with a predetermined space S (specifically, a space S1) to be electrically Because the heating area of the heating unit 40a1 is exactly divided into one, the power supply electrodes 42aa (1) to 42aa (n1) and 42ab (1) to 42ab (n2) are provided electrically independently. ) At the center in the lateral direction C between one feed layer 40c1 to 40c1 electrically connected to the other feed side and the other feed layer 40c2 to 40c2 electrically connected to the other feed electrode 42b. There is no problem in practical use, and the area control of heat generation can be performed more reliably.

  Further, the other feed layer 40c2 electrically insulates, as a conduction guide portion, a portion corresponding to the space between the other adjacent feed electrodes 42b and 42b in the other feed electrodes 42b to 42b divided in the longitudinal direction D. By providing the predetermined distance S (specifically, the space S1) to be electrically separated, it is possible to make the individual heat generating regions in the heat generating layer 40d clearer.

  In the second embodiment, as in the first embodiment, the other feed layer 40c2 may be integrally formed (continuously in the longitudinal direction D). Further, in the first embodiment, as in the second embodiment, both the one feeding layer 40c1 and the other feeding layer 40c2 are electrically divided by providing the predetermined spacing S (specifically, the space S1). It may be done.

Third Embodiment
Next, the configuration of the fixing device 15 according to the third embodiment will be described below with reference to FIGS. 17 to 20. FIG.

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

  The fixing device 15 according to the third embodiment is the first except for the fixing member 41B, one of the feeding electrodes 42a, one of the feeding patterns 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, the same reference numerals are given to members having the same configuration, and here, points different from the first embodiment will be mainly described.

  At least one (one in this example) of the pair of feed electrodes 42a and 42b for energizing the heat generating layer 40d in the circumferential direction V (one feed electrode 42a (1) to 42a (n) in this example) (See FIGS. 17 and 18) are electrically provided independently of one another with respect to the longitudinal direction D of the fixing member 41B (direction along the surface of the recording material P orthogonal to the conveyance direction W of the recording material P). ing. In this example, n is set to 16.

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

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

  The fixing member 41B is, as shown in FIGS. 17 to 19, formed of a long member (in this example, a substantially hexahedral block body) elongated in the longitudinal direction D. The fixing member 41B has a pair of feed electrodes 42a and 42b attached to both ends in the short direction C or in the vicinity of the both ends (in this example, both ends). In this example, the fixing member 41B has a size (see FIGS. 18 and 19), a length L2 (size in the longitudinal direction D) = 320 mm, a width W2 (size in the lateral 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, a feed pattern (in this example, one feed) electrically connected to a plurality of feed electrodes (in this example, one feed electrode 42a) provided electrically independently of the pair of feed patterns 44 and 45. The pattern 44) is one of the surface on the heating member 40 side (hereinafter referred to as the upper surface 41a) of the fixing member 41B and the surface on the opposite side to the heating member 40 (hereinafter referred to as the lower surface 41b) (in this example). It is provided on the lower surface 41b).

  One feed 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 to the one feed electrode 42a. And a line portion 44b electrically connected between the terminal portion 44a and one of the feed electrodes 42a through the switching elements 46a (1) to 46a (n). ing.

  The terminal portions 44a are provided at both ends 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 the connection of the cable wiring from the power supply 43. .

  The line portion 44b includes one bus line portion 44b1 and a plurality of connection line portions 44b2, and a plurality of electrically independent power supply electrodes 42a (1) are provided separately from the bus line portion 44b1. The connection line portion 44b2 branches one by one with respect to 42a (n), and is electrically connected through 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, control signals can be sent from the control device 20 to the switching elements 46a (1) to 46a (n). The signal line 47 is a terminal portion 47a electrically connected to the control device 20 side, and a line electrically connected 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 portions 47a are provided at both ends in the longitudinal direction D of the fixing member 41B, and in terms of facilitating connection of signal lines (harnesses) from the control device 20, the width is greater than the width of the line portions 47b. It is getting wider. Further, since the signal line 47 is on the secondary side while the pair of feed patterns 44 and 45 are on the primary side, the width of the terminal portion 47a on the secondary side is the terminal portions 44a and 45a on the primary side. It can be smaller than that.

  The one feed electrode 42 a electrically connects the one feed pattern 44 to the one feed layer 40 c 1 of the heating member 40, and is made of metal such as stainless steel or copper.

  One of the feed electrodes 42a is a metal plate having elasticity (spring). Thus, one of the feed electrodes 42a is a metal plate having elasticity (spring property), so that the elasticity of the metal plate (spring property) ensures that one of the feed layers 40c1 is at a predetermined pressure. It can be made to abut. Further, the side of the one feeding electrode 42a in contact with the one feeding layer 40c1 of the heating member 40 protrudes from the upper surface 41a of the fixed member 41B, and the free end 42a1 (see FIG. 19) It is formed to be bent in an L shape or a substantially L shape and to be inclined inward in the lateral direction C. Thus, one of the feed electrodes 42a is formed such that the free end 42a1 is bent in an L-shape or a substantially L-shape inward in the latitudinal direction C and inclined inward in the latitudinal direction C. As a result, one feed layer 40c1 can be stably abutted.

  Further, one of the feed electrodes 42a is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41B (specifically, the heating member 40 side of the lower surface 41b of the fixing member 41B) (FIGS. 17 and 18). reference). In this example, one of the feed electrodes 42a is divided into n (specifically, 16). In this manner, one feed electrode 42a is divided into a plurality in the longitudinal direction D on the upper surface 41a side of the fixing member 41B (specifically, the heating member 40A side of the lower surface 41b of the fixing member 41). As compared with the case of the integral shape, it is possible to contact the one feed layer 40c1 more stably.

  The side electrically connected to one feed pattern 44 of one of the feed electrodes 42a (1) to 42a (n) is bent in an L-shape inside the short direction C as shown in FIG. It fixes to the fixing member 41B so that the surface facing the fixing member 41B of the L-shaped part may closely_contact | adhere to the lower surface 41b of the fixing member 41B.

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

  The fixing member 41B (see FIGS. 17 and 18) has a comb shape having a plurality of concavo-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). The pair of feed electrodes 42a and 42b are respectively fitted in the recesses. The fixing member 41B and the pair of feed electrodes 42a and 42b can be fixed by a fixing member such as a screw or a heat-resistant adhesive.

  Switching elements 46a (1) to 46a (n) are turned on by the instruction signal from control device 20 to one of feed electrodes 42a (1) to 42a (n) provided electrically independently. -Off control.

  In addition, the switching elements 46a (1) to 46a (n) are for the plurality of (16 in this example) connection terminals 46c (1) to 46c (n) whose signal terminals are provided on the upper surface 41a of the fixing member 41B. In addition, the fixing members 41B are electrically connected to each other 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.

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

  Although any semiconductor element can be used as the switching elements 46a (1) to 46a (n), the inside of the fixing device 15 has a very high temperature and heat resistance is required, so in this example, A silicon carbide (SiC) semiconductor excellent in heat resistance is used.

  FIG. 20 is a schematic view schematically showing a heat generation area of the heating member 40 in the fixing device 15 according to the third embodiment. In the example shown in FIG. 20, a state is shown in which all the regions corresponding to one of the feed 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 feeding electrode 42b side is electrically integrated, the heat generation area of the heating unit 40a1 is electrically independent. The other feeding layer 40c2 electrically connected to the other feeding electrode 42b from the side of one feeding layer 40c1 to 40c1 electrically connected to the provided feeding electrode 42a (1) to 42a (n) However, there is no particular problem in practical use, and heat generation area control can be reliably performed, and the other side of the feeding electrode 42b is electrically integrated. Thus, the number of heat generation areas can be increased while simplifying the shape of the other feed pattern 45 (see FIG. 18).

  In the third embodiment, as in the second embodiment, both the one feeding layer 40c1 and the other feeding layer 40c2 are electrically divided by providing a predetermined space S (specifically, the space S1). It may be done.

(For the third embodiment)
According to the fixing device 15 of the third embodiment, in addition to the function and effect of the fixing device 15 of the first embodiment, a plurality of feed electrodes 42a (1) to 42a (n Is electrically connected to the switching elements 46a (1) to 46a (n) individually to turn on / off energization of the divided feed electrodes 42a (1) to 42a (n). It becomes possible to perform control easily and easily.

  Further, in the third embodiment, although the ambient temperature inside the fixing device 15 is high, the switching elements 46a (1) to 46a (n) are made of silicon carbide (SiC) semiconductor, so that heat resistance is achieved. Therefore, the switching device can be made excellent in the characteristics, and thus, it is suitable for the switching device used for 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 feed patterns that require a certain width (area) to flow a large current. it can. In this example, compared to the first embodiment, it is possible to increase the number of heat generating areas from eight to 16 in the longitudinal direction D of the fixing device 15. Therefore, it is possible to perform area control of heat generation more finely.

  As a result, it becomes possible to control the temperature of the heat generation area more finely with respect to various sizes of the recording material P and the image formation pattern, and the 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 as well as the effect of suppressing unnecessary heating in the area where image formation is not performed can be further improved, which can contribute to energy saving.

(Other embodiments)
In the first embodiment, the pair of feed 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 feed patterns 44 and 45 can be formed on the upper surface 41 a of the fixing member 41.

  In the second embodiment, the other feed 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 feed pattern 45 can be formed on the upper surface 41 a of the fixing member 41.

  In the third embodiment, the pair of feed 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 feed 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. Also, 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 embodiments described above, and can be implemented in other various forms. Therefore, such an embodiment is merely illustrative in every point and should not be interpreted in a limited manner. The scope of the present invention is indicated by the scope of the claims, and is not limited at all by the text of the specification. Furthermore, all variations and modifications that fall within the equivalent scope of the claims fall 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 device 20 control device 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 (example of pressure member)
31a Core metal 31b Elastic layer 31c Releasing layer 32 Fixing belt 32a Fixing belt inner circumferential surface 33 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 portion 40a2 skirt portion 40b1 first insulating layer 40b2 second insulating layer 40c1 one feeding layer 40c1 feeding layer 40c2 the other feeding layer 40d heating layer 40f both ends 41 fixed member 41A fixed member 41B fixed member 41a upper surface 41b of fixed member lower surface 42a of fixed member one feed electrode 42a1 free end 42aa one feed electrode 42ab one feed electrode 42b other feed electrode 42b1 free end 43 power supply 44 One feed pattern 44a Terminal 44b Line 44b1 Bus line 44b2 Connection line 45 Other feed pattern 46a Switching element 46b Cable 46c Connection terminal 47 Signal line 47a Terminal 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 W circumferential direction transport direction α first virtual straight line β second virtual straight line θ tilt angle

Claims (11)

An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material,
The heating member has a curved heating portion which is convexly curved toward the fixing belt.
The heating component for heating the fixing belt includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction .
The heating member and the fixing member extend in a direction along a surface of the fixing belt orthogonal to the circumferential direction,
The heating member includes a heat generating layer formed entirely or substantially entirely in a heating area of the heating unit,
The pair of feed electrodes for feeding power to the heat generating layer are configured to energize the heat generating layer in the circumferential direction,
Among the pair of feed electrodes for energizing the heat generating layer in the circumferential direction, at least one of the feed electrodes is electrically provided in a plurality independently of each other in the longitudinal direction of the fixing member,
A feeding pattern for electrically connecting a power supply side and the plurality of feeding electrodes provided electrically independently of each other is provided on both sides in the thickness direction of the fixing member. apparatus. An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material,
The heating member has a curved heating portion which is convexly curved toward the fixing belt.
The heating component for heating the fixing belt includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction.
The heating member and the fixing member extend in a direction along a surface of the fixing belt orthogonal to the circumferential direction,
The heating member includes a heat generating layer formed entirely or substantially entirely in a heating area of the heating unit,
The pair of feed electrodes for feeding power to the heat generating layer are configured to energize the heat generating layer in the circumferential direction,
Among the pair of feed electrodes for energizing the heat generating layer in the circumferential direction, at least one of the feed electrodes is electrically provided in a plurality independently of each other in the longitudinal direction of the fixing member,
A fixing device, wherein the plurality of feed electrodes provided independently of one another are electrically connected to switching elements individually. An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material,
The heating member has a curved heating portion which is convexly curved toward the fixing belt.
The heating component for heating the fixing belt includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction.
The heating member and the fixing member extend in a direction along a surface of the fixing belt orthogonal to the circumferential direction,
The heating member includes a heat generating layer formed entirely or substantially entirely in a heating area of the heating unit,
The pair of feed electrodes for feeding power to the heat generating layer are provided at both ends in the short direction of the fixing member with respect to the fixing member or in the vicinity of the both ends,
Among the pair of feed electrodes for energizing the heat generating layer in the circumferential direction, at least one of the feed electrodes is electrically provided in a plurality independently of each other in the longitudinal direction of the fixing member,
A feeding pattern for electrically connecting a power supply side and the plurality of feeding electrodes provided electrically independently of each other is provided on both sides in the thickness direction of the fixing member. apparatus. An endless fixing belt which is stretched by a fixing member, a heating member, the fixing member and the heating member, and which is heated by the heating member while moving to one side in the circumferential direction; And a pressing member that is in pressure contact with the fixing member and that forms a fixing nip portion with the fixing belt at the pressure contact portion with the fixing member via the fixing belt, recording passing through the fixing nip portion A fixing device for fixing an unfixed image on a recording material to the recording material,
The heating member has a curved heating portion which is convexly curved toward the fixing belt.
The heating component for heating the fixing belt includes the heating member and a fixing member which bridges and fixes both sides of the heating member in the circumferential direction.
The heating member and the fixing member extend in a direction along a surface of the fixing belt orthogonal to the circumferential direction,
The heating member includes a heat generating layer formed entirely or substantially entirely in a heating area of the heating unit,
The pair of feed electrodes for feeding power to the heat generating layer are provided at both ends in the short direction of the fixing member with respect to the fixing member or in the vicinity of the both ends,
Among the pair of feed electrodes for energizing the heat generating layer in the circumferential direction, at least one of the feed electrodes is electrically provided in a plurality independently of each other in the longitudinal direction of the fixing member,
A fixing device, wherein the plurality of feed electrodes provided independently of one another are electrically connected to switching elements individually. The fixing device according to claim 3 or 4 , wherein
A pair of feed electrodes for feeding power to the heat generating layer, wherein the heat generating layer is configured to be energized in the circumferential direction. The fixing device according to any one of claims 1 to 5 , wherein
The fixing device is characterized in that it is made of heat resistant resin or ceramic. The fixing device according to any one of claims 1 to 6, wherein
A fixing device according to claim 1, wherein the heating member is provided with an energization guide portion which respectively directs the energization direction of the plurality of feed electrodes provided independently of one another electrically to the circumferential direction. A fixing device according to any one of claims 1 to 7,
A fixing device, wherein the plurality of feed electrodes provided independently of one another are electrically connected to switching elements individually. The fixing device according to claim 8 ,
The fixing device, wherein the switching element is made of a silicon carbide (SiC) semiconductor. The fixing device according to any one of claims 1 to 9 , wherein
The fixing device according to claim 1, wherein the heating unit is disposed close to the entrance side of the fixing nip portion in the conveyance direction of the recording material. An image forming apparatus comprising the fixing device according to any one of claims 1 to 1 0.

Images