JP2010177142A - Heating member, fixing device, and image forming apparatus with fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating member with a heat generating member with an insulating layer and an exothermic layer made of a resistance heating element laminated, in which a local peeling between members composing the heat generating member is prevented from occurring and a local degradation in the efficiency of heat conductivity is prevented from occurring and there is no unevenness of surface temperature distributions against an established temperature. <P>SOLUTION: The heating member 20 includes a heat dissipation member 201, a low hardness good heat conductive member 202, the heat generating member 203, and a pressing member 204 for pressing elastically the heat generating member 203 and the heat dissipation member 201 in an approacing direction. Then, the heat dissipation member 201 inludes and is composed of a cylindrical part 201a composing part of a cylindircal body and bent pieces 201b bent inside from both ends in a peripheral direction of the cylindrical part 201a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heating member having a heat generating layer composed of a resistance heating element that generates heat when energized, a fixing device that fixes a toner image on a recording medium using the heating member, and an image forming apparatus including the fixing device.

  As a fixing device used in an electrophotographic image forming apparatus such as a copying machine or a printer, a heat roller fixing type fixing device is frequently used. A heat roller fixing type fixing device includes a roller pair (fixing roller and pressure roller) that are in pressure contact with each other, and the roller is heated by a heating unit including a halogen heater or the like disposed inside or both of the roller pair. After the pair is heated to a predetermined temperature (fixing temperature), a recording medium such as a recording sheet on which an unfixed toner image is formed is fed to the pressure contact portion (fixing nip portion) of the roller pair and passed through the pressure contact portion. Therefore, the toner image is fixed on the recording paper by heat and pressure.

  By the way, 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 silicon rubber or the like on the surface of the fixing roller. By using an elastic roller as the fixing roller, the surface of the fixing roller is elastically deformed corresponding to the unevenness of the unfixed toner image, and comes into contact so as to cover the toner image surface. It is possible to perform heat fixing on an unfixed toner image satisfactorily. In addition, a color image forming apparatus using an elastic roller as a fixing roller can improve releasability for color toners that are more likely to be offset than monochrome because of the strain relief effect of the elastic layer at the fixing nip. Further, the color image forming apparatus can improve the peeling performance of the recording paper because the nip shape of the fixing nip portion is convex upward (on the fixing roller side) (so-called reverse nip shape). The recording paper can be peeled without using a peeling means such as (self-stripping), and image defects caused by the peeling means can be eliminated.

  By the way, in order to obtain a color image forming apparatus corresponding to high speed, a fixing device provided in the color image forming apparatus needs to be configured so that a fixing nip portion having a wide nip width is formed. Examples of a method for widening the nip width of the fixing nip portion include a method of increasing the thickness of the elastic layer of the fixing roller and a method of increasing the diameter of the fixing roller. However, since the elastic layer of the fixing roller has a very low thermal conductivity, there is a problem that the surface temperature of the fixing roller does not follow the increase in the process speed when there is a heating means inside the fixing roller. On the other hand, when the diameter of the fixing roller is increased, problems such as an increase in warm-up time until the surface temperature of the fixing roller reaches the fixing temperature and an increase in power consumption occur.

  As a fixing device provided in a color image forming apparatus that solves such a problem, Patent Document 1 discloses a fixing device of a belt fixing type. A belt-fixing type fixing device includes a fixing belt suspended between a fixing roller and a heating roller, and a pressure roller disposed so as to face the fixing roller via the fixing belt. The fixing belt is heated by a heat source disposed inside the roller. In the belt-fixing type fixing device, a fixing nip portion is formed at a pressure contact portion where the fixing roller is pressed against the pressure roller via the fixing belt. Such a belt-fixing type fixing device is configured to heat a fixing belt having a small heat capacity, so that the warm-up time until the surface temperature of the fixing belt reaches the fixing temperature can be shortened. In addition, since the belt fixing type fixing device does not require a heating means such as a halogen lamp inside the fixing roller, use a fixing roller provided with a thick low-elastic layer made of sponge rubber or the like. And a fixing nip portion having a wide nip width can be formed.

  Patent Document 2 is a configuration in which a sheet heating element configured such that a resistance heating element that generates heat when energized forms a surface having a certain shape as a whole is used as a heating member that heats the fixing belt. A sheet heating belt fixing type fixing device is disclosed. A sheet heating belt fixing type fixing device includes a fixing belt suspended between a fixing roller and a heating member made of a sheet heating element, and a pressure disposed so as to face the fixing roller via the fixing belt. The fixing belt is heated by a heating member that contacts the fixing belt. Such a sheet heating belt fixing type fixing device can be designed to have a small heat capacity of a heating member for heating the fixing belt, and the sheet heating element that generates heat directly contacts the fixing belt to fix the fixing belt. Since it is configured to heat, compared to a system configured to indirectly heat the fixing belt by a heat source arranged inside the heating roller, the thermal response speed is improved and the warm-up time is further increased. Shortening and energy saving can be achieved. In this way, the sheet heating belt fixing type fixing device has high heating efficiency and fast start-up speed, which makes it possible to eliminate the need for preheating during standby and shorten the waiting time. In addition, it is provided in an image forming apparatus of a large machine or a high speed machine.

  Here, in a fixing device that obtains a predetermined fixing temperature via a fixing belt, such as the fixing device disclosed in Patent Document 2, a sheet heating element that heats the fixing belt is large in order to prevent fixing failure. It must have heat generation capacity. A planar heating element having a large heat generation capacity can be achieved by increasing the length extending in the circumferential direction to increase the area of the planar heating element itself.

  When the length extending in the circumferential direction of the semicircular arc-shaped substrate is increased, the opening is narrowed. When a planar heating element is formed on the inner surface of the base material with the opening narrowed in this way by painting, screen printing method, pasting or the like, the planar heating element faces the inner side from the narrowed opening side. Therefore, it is difficult to hold and fix the planar heating element in a state where the entire surface of the planar heating element is uniformly in contact with the inner surface of the substrate. Therefore, local abnormal heat generation of the sheet heating element occurs, the temperature distribution on the sheet heating element surface becomes non-uniform with respect to the set temperature, the fixing temperature varies, and high printing quality cannot be maintained.

  As a method for solving such a problem, Patent Document 3 discloses a heat fixing that can be mounted on a fixing device in which a planar heating element is fixed to an inner surface of a cylindrical roller member via an insulating layer. A roller is disclosed. In the heat-fixing roller disclosed in Patent Document 3, a planar heating element in which an insulating layer and a heating layer composed of a resistance heating element are laminated is pressed through an adhesive while being pressed by an elastic body. It is fixed to the inner surface of the roller member. In the heat fixing roller disclosed in the cited document 3, the sheet heating element is fixed to the inner surface of the roller member via an adhesive in a state where a pressing force is applied by an elastic body. The entire surface of the body is in uniform contact with the inner surface of the roller member, and the temperature distribution on the surface of the planar heating element is prevented from becoming uneven with respect to the set temperature.

Japanese Patent Laid-Open No. 10-30796 JP 2002-333788 A JP 11-119575 A

  Here, each material constituting the roller member, the insulating layer of the sheet heating element and the heating layer included in the heat fixing roller disclosed in Patent Document 3 has a different thermal expansion coefficient. That is, in the heat fixing roller disclosed in Patent Document 3, a planar heating element including an insulating layer and a heat generating layer made of a material having a thermal expansion coefficient different from that of the material constituting the roller member is provided on the inner surface of the roller member. It is fixed via an adhesive. In such a heat fixing roller, when a voltage is applied to the resistance heating element constituting the heat generating layer and the heat generating layer generates heat, and the heat fixing roller itself is heated, the roller member, the insulating layer, and the heat generating layer are different from each other. It will thermally expand to a certain degree.

  In the heat fixing roller disclosed in Patent Document 3, the planar heating element is fixed to the inner surface of the roller member via an adhesive in a state where a pressing force is applied by an elastic body. The thermal expansion difference between the heat generating layer and the heat generation layer cannot be absorbed and relaxed, and the interface between the roller member and the insulating layer and the interface between the insulating layer and the heat generating layer are locally peeled only by the pressing force of the elastic body. As a result, the heat transfer efficiency with respect to the inner surface of the roller member is locally reduced. As described above, when the heat transfer efficiency with respect to the inner surface of the roller member is locally reduced, the temperature distribution on the surface of the heat fixing roller becomes non-uniform with respect to the set temperature, the fixing temperature varies, and the fixing performance deteriorates. The print quality cannot be maintained. In addition, when the local heat transfer efficiency decreases, it becomes necessary to increase the warm-up time until a desired fixing temperature is obtained, or a larger amount of heat is required to obtain the desired fixing temperature. There arises a problem that power consumption increases. Further, when the local peeling occurs, the heat generated in the heat generating layer is lost from being transmitted to the roller member, and the sheet heating element itself is overheated, which causes deterioration of the insulating layer and electrical insulation. Loss of safety occurs, resulting in a safety problem.

  When the heat fixing roller itself is heated, the cylindrical roller member thermally expands in the radial direction so that the outer diameter becomes large. On the other hand, since the elastic body that applies a pressing force to the planar heating element extends in the axial direction of the roller member, the pressing force applied to the planar heating element decreases toward the inner surface of the roller member. . Therefore, the phenomenon in which the interface between the roller member and the insulating layer and the interface between the insulating layer and the heat generating layer are locally peeled becomes more prominent.

  Accordingly, an object of the present invention is a heating member having a heating member in which a heating layer composed of an insulating layer and a resistance heating element is laminated, and local peeling between members constituting the heating member is prevented. Thus, it is possible to provide a heating member in which a local decrease in heat transfer efficiency is prevented and the surface temperature distribution is uniform with respect to the set temperature. Another object of the present invention is a belt-fixing type fixing device, which prevents the fixing temperature from fluctuating with respect to a set temperature, ensures safety, shortens the warm-up time, and increases power consumption. It is an object of the present invention to provide a fixing device that can be prevented. Another object of the present invention is to provide an image forming apparatus capable of forming a uniform and high-quality image by including a fixing device having a uniform fixing characteristic in which the fixing temperature is prevented from varying with respect to a set temperature. It is to be.

The present invention includes a heat dissipating member having a cylindrical portion formed in a cylindrical shape that forms a part of a cylindrical body, and a bent piece that is bent inward from at least a part of both circumferential ends of the cylindrical portion;
A material having low hardness and high thermal conductivity, and a low hardness and good thermal conductive member provided in contact with the inner peripheral surface of the heat radiating member;
It has a heat generating layer made of a resistance heating element that generates heat when energized and an insulating layer made of an insulator, and the insulating layer is laminated so as to sandwich the heat generating layer, and is formed on the inner peripheral surface of the low-hardness heat-conductive member. A heat generating member provided in contact;
The heat generating member is formed in a cylindrical shape forming a part of a cylindrical body, contacts the inner peripheral surface of the heat generating member on the outer peripheral surface, and elastically presses the heat generating member in a direction close to the heat radiating member. And a pressing member that holds the member,
The bent piece of the heat radiating member is formed by bending from at least a part of both ends in the circumferential direction of the cylindrical portion in a direction approaching the pressing member, and in a direction approaching the heat generating member with respect to the pressing member It is a heating member characterized by having a bent part which gives a pressing force to.

  Further, the present invention is characterized in that a plurality of the bent pieces of the heat dissipation member are provided at intervals in the axial direction of the cylindrical portion.

  Further, in the present invention, the pressing member deforms a member having a radius of curvature R2 in the circumferential direction larger than the radius of curvature R1 in the circumferential direction of the cylindrical portion of the heat radiating member so as to be inside the cylindrical portion. It is characterized by being arranged.

In the present invention, the heat dissipation member is formed using an alloy selected from an aluminum alloy, a magnesium alloy, and a copper alloy,
The pressing member is formed to have elasticity using a material selected from a metal, a heat resistant resin, and ceramics.

In the present invention, the resistance heating element constituting the heat generating layer of the heat generating member extends in a circumferential direction of the heat radiating member, and is adjacent to a plurality of linear portions formed on the surface of the insulating layer. The extending portions of the linear portions are connected to each other so as to extend in the axial direction of the heat radiating member so as to form one line, and are formed on the surface of the insulating layer.
The pressing member is configured such that a plurality of openings that penetrate through and open in the thickness direction are regularly arranged at intervals.
The minimum width dimension of the opening peripheral edge part that defines each of the plurality of openings in the pressing member is greater than or equal to the line width of the linear part and the connection part of the resistance heating element.

According to the present invention, the pressing member is formed such that the axial length of the pressing member is larger than the axial lengths of the heat radiating member and the heat generating member. Having an extension part extending toward
The extension portion is provided with a fixing adapter configured to be connected to the outside so as to fix the pressing member.

  Further, according to the present invention, an elevation angle with respect to the axial lines at both ends in the circumferential direction in the cylindrical portion of the heat dissipation member is selected from 180 ° to 320 °.

  In the invention, it is preferable that an inner surface coating layer made of a material having heat resistance and high heat radiation is formed on the inner peripheral surface of the heat radiating member that is in contact with the low-hardness and heat-conductive member. .

  Further, the present invention is characterized in that an outer surface coating layer made of a material having heat resistance and a low friction coefficient is formed on the outer peripheral surface of the heat radiating member.

  In the invention, it is preferable that the outer surface coating layer is made of at least one material of PTFE resin and PFA resin containing fluorine.

The present invention also provides a rotatable endless belt stretched between a first fixing member and a heating member, and a second end disposed so as to face the first fixing member via the endless belt. And a fixing device that heats and fixes the toner image carried on the recording medium at a fixing nip portion formed by contact between the endless belt and the second fixing member. Because
In the fixing device, the heating member is a heating member having a bent piece, and heats the endless belt in contact with the endless belt on an outer peripheral surface of the heat radiating member.
According to another aspect of the present invention, there is provided an image forming apparatus comprising the fixing device.

  According to the present invention, the heating member is disposed in contact with the heat dissipating member, the low hardness and good heat conducting member disposed in contact with the inner peripheral surface of the heat dissipating member, and the inner surface of the low hardness and good heat conducting member. And a pressing member that elastically presses the heat generating member in a direction close to the heat radiating member. And a heat radiating member contains the cylindrical part formed in the cylinder shape which comprises a part of cylindrical body, and the bending piece bent inside from the circumferential direction both ends of a cylindrical part. Further, the bent portion provided on the bent piece bends in a direction approaching the pressing member from at least a part of both ends in the circumferential direction of the cylindrical portion, and applies a pressing force in a direction approaching the heat generating member to the pressing member. It is configured to grant.

  In the heating member of the present invention, the heat generating member is pressed by the pressing member in the direction approaching the heat radiating member, and is fixed to the inner peripheral surface of the heat radiating member. At this time, the pressing member is applied with a pressing force in a direction approaching the heat generating member by a bent portion provided in the bending piece, and thus the pressing force acts as a force for pressing the heat generating member in a direction approaching the heat radiating member. . Thereby, the heat generating member is fixed in a state in which the adhesion to the inner peripheral surface of the heat radiating member is improved.

  In addition, since a low-hardness heat-conductive member made of a material having low hardness and high thermal conductivity is disposed between the heat-dissipating member and the heat-generating member, the heat transfer efficiency from the heat-generating member to the heat-dissipating member is reduced. Therefore, it is possible to absorb and relax the difference in thermal expansion of each member constituting the heating member, and to prevent local peeling between the members. Thus, since the heating member of the present invention is maintained in a state in which the heat generating member has high adhesion to the inner peripheral surface of the heat radiating member, it is possible to prevent local peeling between the members. The local heat transfer efficiency is prevented from being lowered, and the surface temperature distribution is a heating member having no variation with respect to the set temperature.

  Moreover, according to this invention, the bending piece which a heat radiating member has is provided with two or more in the axial direction of a cylindrical part at intervals. In the case where the bent pieces are provided over the entire region in the axial direction at both ends in the circumferential direction of the cylindrical portion, the heat capacity of the heating member is increased. On the other hand, it can suppress that the heat capacity of a heating member becomes large by providing a some bending piece at intervals in the axial direction of a cylindrical part.

  According to the invention, the pressing member is disposed inside the cylindrical portion by deforming a member having a radius of curvature R2 in the circumferential direction larger than the radius of curvature R1 in the circumferential direction of the cylindrical portion of the heat dissipation member. ing. As described above, the pressing member disposed inside the heat radiating member in the heating member is arranged in a deformed state, and thus the pressing member is subjected to a force to restore the deformation, and the restoration to be restored is performed. The force acts as a force that elastically presses the heat generating member in the direction of approaching the heat radiating member. As described above, the restoring force of the pressing member acts so as to hold the heat generating member on the inner peripheral surface of the heat radiating member, so that the heat generating member is fixed with improved adhesion to the inner peripheral surface of the heat radiating member. Is done.

  According to the invention, the heat dissipation member is formed using an alloy selected from an aluminum alloy, a magnesium alloy, and a copper alloy. Since the heat radiating member comprised with the said material turns into a member which has high heat conductivity, it can heat a heating target object efficiently. Furthermore, the pressing member is formed to have elasticity using a material selected from metals, heat-resistant resins, and ceramics. Since the pressing member made of the material is a member having high strength and high toughness, it has a large elasticity without being broken even if it is bent, and the heat generating member is elastic in the direction close to the heat radiating member. The pressing force increases. Therefore, the heat generating member is fixed in a state where the adhesion to the inner peripheral surface of the heat radiating member is improved.

  According to the present invention, the resistance heating element constituting the heat generating layer of the heat generating member extends in the circumferential direction of the heat radiating member, and a plurality of linear portions formed on the surface of the insulating layer in a substantially parallel state, It is comprised including the connection part formed in the surface of an insulating layer by connecting the extension direction edge parts of an adjacent linear part to the axial direction of a thermal radiation member so that it may become one line | wire. . And a press member is comprised so that the several opening part which penetrates and opens in the thickness direction may be regularly arranged at intervals. At this time, the minimum width dimension of the opening peripheral edge that defines each of the plurality of openings in the pressing member is equal to or greater than the line width of the linear portion and the connecting portion of the resistance heating element. Accordingly, the pressing member can apply a sufficient pressing force to the inner peripheral surface portion of the heat generating member corresponding to the region where the resistance heating element is disposed. Therefore, the area | region part of the heat generating member corresponding to the area | region where a resistance heating element is arrange | positioned fully contact | adheres with respect to the internal peripheral surface of a heat radiating member, and can suppress a local heat transfer efficiency fall.

  Further, according to the present invention, the pressing member is formed such that its axial length is larger than the axial length of the heat radiating member and the heat generating member, and outward from both axial ends of the heat radiating member. It has an extending part that extends. The extension portion is provided with a fixing adapter configured to be connected to the outside so as to fix the pressing member. When the pressing member is fixed to the outside via a fixing adapter provided in the extending portion, the arrangement position of the pressing member with respect to the heat generating member is restricted. In this way, by restricting the arrangement position of the pressing member, the external force due to the restriction can be applied as a pressing force that elastically presses the heat generating member in the direction approaching the heat radiating member. Therefore, the pressing member can stably hold the heat generating member at a predetermined position on the inner peripheral surface of the heat radiating member.

  Moreover, according to this invention, the elevation angle regarding the axis of the circumferential direction both ends in the cylindrical part which a heat radiating member has is chosen from 180 degrees or more and 320 degrees or less. For example, when an endless belt is brought into contact with the outer peripheral surface of the cylindrical part and the heating member is used as a member for heating the endless belt, the elevation angle with respect to the axis at both ends in the circumferential direction of the cylindrical part is 180 ° or more. By setting, the circumferential length of the cylindrical portion is equal to or greater than the contact length between the cylindrical portion and the endless belt corresponding to the circumferential direction of the cylindrical portion (hereinafter referred to as “nip length”). . Thus, by making the circumferential length of the cylindrical portion equal to or greater than the nip length, the heating member can ensure a sufficiently large contact area with the endless belt on the outer peripheral surface of the cylindrical portion, The endless belt can be heated with low power consumption. In addition, by making the circumferential length of the cylindrical portion equal to or greater than the nip length, the contact load on the endless belt at the circumferential end of the cylindrical portion can be reduced, and the endless belt can be worn out. Can be prevented. Further, when the contact load on the endless belt at the circumferential end of the cylindrical portion can be reduced, the driving load for rotating the endless belt can also be reduced, and the energy consumption can be reduced. In addition, by setting the elevation angle with respect to the axis at both ends in the circumferential direction of the cylindrical portion to 320 ° or less, it is possible to prevent the heat capacity of the heating member from becoming too large, and the surface temperature of the heating member reaches the set temperature. It is possible to prevent the time until the process is too long.

  According to the invention, the inner surface coating layer made of a material having heat resistance and high heat radiation is formed on the inner peripheral surface of the heat dissipating member that is in contact with the low-hardness heat-conductive member. Accordingly, it is possible to prevent the occurrence of corrosion at the interface between the heat radiating member and the low hardness and good heat conducting member, and it is possible to prevent a decrease in heat transfer efficiency from the heat generating member to the heat radiating member over a long period of time.

  According to the invention, the outer surface coating layer made of a material having heat resistance and a low friction coefficient is formed on the outer peripheral surface of the heat radiating member. For example, when the endless belt is brought into contact with the outer peripheral surface of the heat radiating member and the heating member is used as a member for heating the endless belt, the frictional force between the heat radiating member and the endless belt can be reduced. It is possible to prevent the endless belt from being worn and to ensure high durability of the endless belt. Further, when the frictional force between the heat radiating member and the endless belt can be reduced, the rotation of the endless belt can be made smooth, and the heat transfer efficiency of the heating member to the endless belt can be prevented from being lowered. Can do.

  Moreover, according to this invention, the outer surface coating layer which can reduce the frictional force between a heat radiating member and a to-be-heated object is implement | achieved with the material which consists of at least any one of PTFE resin and PFA resin containing a fluorine. Can do.

  According to the invention, the fixing device is disposed so as to face the first fixing member via the endless belt stretched between the first fixing member and the heating member, and the endless belt. And a fixing nip formed by contact between the endless belt and the second fixing member, and the toner image is heated and melted and fixed on the recording medium. The fixing device according to the present invention includes the heating member according to the present invention in which the surface temperature distribution does not vary with respect to the set temperature as the heating member, so that the temperature distribution on the surface of the endless belt becomes the set temperature. On the other hand, the fixing device is uniform and the fixing temperature is prevented from varying, and the fixing device has uniform fixing characteristics. Further, since the heating member of the present invention provided in the fixing device is one in which a local decrease in heat transfer efficiency is prevented, the fixing device has a short warm-up time until a desired fixing temperature is obtained, The fixing device prevents an increase in power consumption.

  In addition, according to the present invention, the image forming apparatus includes the fixing device of the present invention, which has a uniform fixing characteristic in which the fixing temperature is prevented from being varied with respect to the set temperature, so that the image forming apparatus is uniform and high quality. An image can be formed on a recording medium.

It is a figure which shows the structure of the heating member 20 which is 1st Embodiment of this invention. FIG. 6 is a diagram showing a configuration of a heat generating member 203. It is a figure which shows the heat_generation | fever pattern of the heat generating member. It is a figure which shows the structure of the heat generating member 303 which has another heat generating pattern. It is a figure which shows the structure of the heat generating member 403 which has another heat generating pattern. 3 is a block diagram showing an electrical configuration of a heating member 20. FIG. It is a figure which shows the structure of the press member. 2 is a diagram illustrating a configuration of a fixed adapter 205. FIG. It is a figure which shows the structure of the heating member 30 which is 2nd Embodiment of this invention. It is a figure which shows the structure of 30 A of heating members which are 3rd Embodiment of this invention. 1 is a diagram illustrating a configuration of a fixing device 15 according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a fixing device 15 in the vicinity of a region where a fixing belt is suspended from a heating member. 3 is a block diagram showing an electrical configuration of the fixing device 15. FIG. It is a figure which shows the structure of the fixing device 40 which is other embodiment of this invention. It is a figure which shows the structure of the fixing device 50 which is other embodiment of this invention. 1 is a diagram illustrating a configuration of an image forming apparatus 100 according to an embodiment of the present invention.

  FIG. 1 is a diagram showing a configuration of a heating member 20 according to the first embodiment of the present invention. FIG. 1A shows a cross section perpendicular to the axial direction of the heating member 20, and FIG. 1B shows a cross section parallel to the axial direction of the heating member. The heating member 20 is disposed in contact with the heat dissipating member 201, the low hardness and good heat conducting member 202 disposed in contact with the inner peripheral surface of the heat dissipating member 201, and the inner surface of the low hardness and good heat conducting member 202. And a pressing member 204 that elastically presses the heat generating member 203 in the direction approaching the heat radiating member 201. In the heating member 20, the heat generated in the heat generating member 203 is conducted to the heat radiating member 201 via the low hardness and good heat conducting member 202, and heats the object that contacts the outer peripheral surface of the heat radiating member 201. The heating member 20 of the present embodiment can be suitably mounted on the fixing device 15 described later. As an object to be heated by the heating member 20, a fixing belt 25 provided in the fixing device 15 will be described as an example.

  The heat radiating member 201 has a cylindrical portion 201a formed in a cylindrical shape that forms a part of a cylindrical body, and a bent piece 201b that bends inward from at least a portion of both ends in the circumferential direction of the cylindrical portion 201a. The cylindrical portion 201 a is disposed on the outer peripheral surface so as to contact the fixing belt 25, and conducts heat generated by the heat generating member 203 to the fixing belt 25. Although the material which comprises the cylindrical part 201a is not restrict | limited in particular, It is preferable that it is a metal material and alloy material which have high heat conductivity, and an aluminum alloy, a magnesium alloy, a copper alloy etc. are mentioned as the material. it can. The cylindrical portion 201a can be produced by cutting out a part of the cylindrical body in the circumferential direction, and can also be produced by curving a plate-like member.

  Moreover, it is preferable that the elevation angle θ related to the axial lines at both ends in the circumferential direction of the cylindrical portion 201a is selected from 180 ° to 320 °. By setting the elevation angle θ with respect to the axial line at both ends in the circumferential direction of the cylindrical part 201a to be 180 ° or more, the circumferential length of the cylindrical part 201a is the same as the cylindrical part 201a corresponding to the circumferential direction of the cylindrical part 201a. The contact length with the fixing belt 25 (nip length) is not less than. Thus, by making the circumferential length of the cylindrical portion 201a equal to or greater than the nip length, the heating member 20 ensures a sufficiently large contact area with the fixing belt 25 on the outer peripheral surface of the cylindrical portion 201a. Therefore, it is possible to heat the fixing belt 25 with low power consumption, and to supply a sufficient amount of heat from the cylindrical portion 201a to the fixing belt 25 to be heated even in high-speed printing with excellent thermal followability. Can do. Further, by making the circumferential length of the cylindrical portion 201a equal to or greater than the nip length, the contact load on the fixing belt 25 at the circumferential end of the cylindrical portion 201a can be reduced, and the fixing belt 25 is worn. Can be prevented. If the contact load on the fixing belt 25 at the circumferential end of the cylindrical portion 201a can be reduced, the driving load for rotating the fixing belt 25 can be reduced, and the energy consumption can be reduced.

  In addition, by setting the elevation angle θ with respect to the axial lines at both ends in the circumferential direction of the cylindrical portion 201a to 320 ° or less, it is possible to prevent the heat capacity of the heating member 20 from becoming too large, and the surface temperature of the heating member 20 can be reduced. It is possible to prevent the time until the set temperature is reached from becoming too long.

  The bent piece 201b has a first bent portion 2011 and a second bent portion 2012, and is a portion bent inward from at least a part of both ends in the circumferential direction of the tubular portion 201a. The bent piece 201b can be formed, for example, by bending both ends in the circumferential direction of the tubular portion 201a inward.

  The 1st bending part 2011 of the bending piece 201b is a part bent in the direction which adjoins the press member 204 mentioned later from at least one part of the circumferential direction both ends of the cylindrical part 201a. The second bent portion 2012 is bent from the end portion of the first bent portion 2011 in a direction approaching a heat generating member 203 described later, contacts the inner peripheral surface of the pressing member 204, and generates heat with respect to the pressing member 204. It is formed so as to apply a pressing force in a direction close to the member 203. In the heating member 20 of the present embodiment, the heat generating member 203 is pressed in the direction approaching the heat radiating member 201 by the pressing member 204 and is fixed to the inner peripheral surface of the heat radiating member 201. Since the pressing force is applied in the direction approaching the heat generating member 203 by the bent portion 2012, the pressing force acts as a force for pressing the heat generating member 203 in the direction approaching the heat radiating member 201. Thereby, the heat generating member 203 is fixed in a state in which the adhesion to the inner peripheral surface of the heat radiating member 201 is improved.

  Further, it is preferable that a plurality of the bent pieces 201b are provided so as to be provided at intervals in the axial direction of the tubular portion 201a. When the bent piece 201b is provided over the entire area in the axial direction at both ends in the circumferential direction of the cylindrical portion 201a, the heat capacity of the heating member 20 is increased. By shortening the length of the second bent portion 2012 extending in the circumferential direction, it is possible to suppress an increase in the heat capacity, but not only the pressing force application capability by the second bent portion 2012 is lowered, but also the bent piece High cost is required for improving processing accuracy when 201b is formed by bending. On the other hand, by providing a plurality of bent pieces 201b at intervals in the axial direction of the cylindrical portion 201a, the length extending in the circumferential direction of the second bent portion 2012 does not need to be extremely shortened, and the processing cost is reduced. However, the heat capacity of the heating member 20 can be suppressed from increasing at a low cost, and the time until the surface temperature of the heating member 20 reaches the set temperature can be prevented from becoming too long.

  Each shape of the plurality of second bent portions 2012 can be arbitrarily set, but is rectangular in the present embodiment. The size of the bent piece 201b is such that the total area in contact with the inner peripheral surface of the pressing member 204 of the second bent portion 2012 is the area of the inner peripheral surface of the pressing member 204 corresponding to the cylindrical portion 201a of the heat radiating member 201. In contrast, it is preferably set to be in the range of 20 to 70%. When the area ratio of the second bent portion 2012 contacting the inner peripheral surface of the pressing member 204 is less than 20%, the pressing force imparting ability by the second bent portion 2012 is not sufficiently exhibited, and the area ratio exceeds 70%. In this case, the heat capacity of the heating member 20 becomes too large. Further, the arrangement interval and the number of the plurality of bent pieces 201b in the axial direction can be set in consideration of the heat capacity of the heating member 20, the pressing force application ability by the second bent portion 2012, and the arrangement interval is 5 mm to 50 mm. It is preferable to set in the range.

  The low-hardness heat-conductive member 202 is provided in contact with the entire inner peripheral surface of the cylindrical portion 201a of the heat dissipation member 201. That is, the low-hardness and high-heat conducting member 202 is interposed between the heat radiating member 201 and a heat generating member 203 described later. The low-hardness heat-conductive member 202 is a member made of a material having low hardness and high thermal conductivity. Here, the “hardness” in the present invention is a hardness calculated by a length of a needle having a specified weight, which is standardized in JIS K2207, which is vertically entered into the sample.

  The low-hardness heat conductive member 202 is preferably formed from a material having a hardness at 25 ° C. of 30 to 300 and a thermal conductivity of 0.5 W / m · K to 30 W / m · K. By interposing the low-hardness heat-conductive member 202 having such physical properties between the heat radiating member 201 and the heat generating member 203, heating can be performed without reducing the heat transfer efficiency from the heat generating member 203 to the heat radiating member 201. The difference in thermal expansion of each member constituting the member 20 can be absorbed and relaxed, and local peeling between the members can be prevented.

  The material constituting the low-hardness heat-conductive member 202 is preferably a material that is excellent in thermal conductivity even in a high-temperature environment and hardly changes over time, such as heat-resistant silicone grease and heat-resistant silicone gel sheet. Can do. Further, in order to further improve the thermal conductivity, a material obtained by adding a powder of gold, silver, copper, platinum, carbon, graphite or the like to the material may be used.

  When a gap is opened between the heat dissipating member 201 and the heat generating member 203, an air layer is interposed, resulting in poor thermal conductivity. On the other hand, by disposing the low-hardness and good heat conductive member 202 between the heat radiating member 201 and the heat generating member 203, the air layer that increases the thermal resistance can be removed, and the thermal conductivity can be improved.

  Next, the heat generating member 203 will be described with reference to FIGS. 2 and 3. FIG. 2 is a diagram illustrating a configuration of the heat generating member 203, and FIG. 3 is a diagram illustrating a heat generation pattern of the heat generating member 203. The heat generating member 203 is held such that a pressing member 204 described later is in contact with the inner peripheral surface, and the outer peripheral surface is in contact with the inner peripheral surface of the low-hardness heat-conductive member 202. The heat generating member 203 has a stacked structure in which the third insulating layer 2034, the heat generating layer 2033, the second insulating layer 2032, and the first insulating layer 2031 are stacked in this order on the surface of the fourth insulating layer 2035. The surface on the side where the first insulating layer 2031 is formed becomes the surface on the side in contact with the inner peripheral surface of the low hardness and good heat conducting member 202, and the surface on the side where the fourth insulating layer 2035 is formed is the outer periphery of the pressing member 204. This is the surface that comes into contact with the surface.

  The first insulating layer 2031, the second insulating layer 2032, the third insulating layer 2034, and the fourth insulating layer 2035 are layers formed of a material having both heat resistance and electrical insulating properties, and each insulating layer is the same It may be formed of a material or may be formed of different materials. The material having both heat resistance and electrical insulation is not particularly limited, and examples thereof include a heat resistant polymer material such as polyimide resin, a ceramic material such as alumina, and an inorganic material such as mica. In the present embodiment, the first insulating layer 2031 and the fourth insulating layer 2035 are layers made of polyimide resin, and the second insulating layer 2032 and the third insulating layer 2034 are layers made of mica.

  The first insulating layer 2031 and the second insulating layer 2032 are interposed between the heat generating layer 2033 and the low-hardness and good heat conducting member 202 to ensure insulation between them, and the third insulating layer 2034 and the fourth insulating layer 2035. Is interposed between the heat generating layer 2033 and the pressing member 204 to ensure insulation between them. As described above, the first insulating layer 2031, the second insulating layer 2032, the third insulating layer 2034, and the fourth insulating layer 2035 electrically insulate the heat generating layer 2033 that generates heat when energized. It can be set as the heating member 20 which has. In addition, when the heat generating layer 2033 can be electrically insulated, for example, even if a low heat capacity metal material such as aluminum or stainless steel is used as a constituent material of the heat radiating member 201, electrical insulation from the heat generating layer 2033 is ensured. The selection range of the material which the heat radiating member 201 comprises can be expanded.

  The heat generating layer 2033 is a layer formed of a resistance heating element that generates Joule heat when energized, and corresponds to each of both end portions in the axial direction of the cylindrical portion 201a, and a heat generating region formed of the first resistance heating element 2033a and a third resistance. A heat generating area formed of the heat generating body 2033g is formed, and a heat generating area formed of the second resistance heat generating body 2033d is formed corresponding to the central portion in the axial direction of the cylindrical portion 201a. That is, in the heat generating layer 2033, the heat generating region is divided into three parts corresponding to both ends in the axial direction and the center of the cylindrical portion 201a. The heat generation layer 2033 is a total of the heat generation region divided into three corresponding to both axial end portions and the central portion of the cylindrical portion 201a and divided into two corresponding to the circumferential direction of the cylindrical portion 201a. You may comprise so that it may have the heat_generation | fever area | region divided into six.

The first resistance heating element 2033a, the second resistance heating element 2033d, and the third resistance heating element 2033g are made of a material mainly composed of nickel chromium having a volume resistivity of about 107.3 × 10 ⁻⁸ Ωcm. The first resistance heating element 2033a, the second resistance heating element 2033d, and the third resistance heating element 2033g preferably have positive resistance temperature characteristics. In a resistance heating element having negative resistance temperature characteristics, the electrical resistance value of the resistance heating element itself decreases as the temperature rises, so that the current flowing through the resistance heating element increases and the power consumption increases. Therefore, a resistance heating element having negative resistance temperature characteristics is not preferable from the viewpoint of energy saving.

  The first resistance heating element 2033a extends in the circumferential direction of the cylindrical portion 201a, and a plurality of linear portions 2043b formed on the surface of the third insulating layer 2034 in a substantially parallel state, and adjacent linear portions. And a connecting portion 2043a formed on the surface of the third insulating layer 2034 by connecting the end portions in the extending direction of 2043b in the axial direction of the cylindrical portion 201a to form one line. Composed. Note that the connecting portion 2043a and the linear portion 2043b are formed with the same material and the same line width. Then, both end portions of the first resistance heating element 2033a are connected to the first power supply terminal portion 2033b and the second power supply terminal portion 2033c, respectively.

  The second resistance heating element 2033d extends in the circumferential direction of the cylindrical portion 201a, and is adjacent to the plurality of linear portions 2043d formed on the surface of the third insulating layer 2034 in a substantially parallel state. The connecting portions 2043c formed on the surface of the third insulating layer 2034 by connecting the ends of the extending portions 2043d in the extending direction in the axial direction of the cylindrical portion 201a to form one line. Consists of including. Note that the connecting portion 2043c and the linear portion 2043d are formed of the same material and the same line width. And each of the both ends of the 2nd resistance heating element 2033d is connected to the 3rd electric power feeding terminal part 2033e and the 4th electric power feeding terminal part 2033f.

  The third resistance heating element 2033g extends in the circumferential direction of the cylindrical portion 201a and is adjacent to the plurality of linear portions 2043f formed on the surface of the third insulating layer 2034 in a substantially parallel state. The connecting portions 2043e formed on the surface of the third insulating layer 2034 by connecting the ends in the extending direction of the shaped portions 2043f so as to extend in the axial direction of the tubular portion 201a to form one line. Consists of including. Note that the connecting portion 2043e and the linear portion 2043f are formed of the same material and the same line width. Then, both end portions of the third resistance heating element 2033g are connected to the fifth power supply terminal portion 2033h and the sixth power supply terminal portion 2033i, respectively.

  The second feeding terminal portion 2033c to which one end portion of the first resistance heating element 2033a is connected and the fifth feeding terminal portion 2033h to which one end portion of the third resistance heating body 2033g is connected are a lead wire 2033j. Connected through. Further, the first feeding terminal portion 2033b to which the other end portion of the first resistance heating element 2033a is connected and the sixth feeding terminal portion 2033i to which the other end portion of the third resistance heating body 2033g is connected are the heating control means 206. It is connected to the power supply via The third power supply terminal portion 2033e and the fourth power supply terminal portion 2033f to which each of the second resistance heating elements 2033d is connected are connected to a power source via the heating control means 206.

  The first resistance heating element 2033a, the second resistance heating element 2033d, and the third resistance heating element 2033g having the connection structure as described above are energized and controlled by the heating control means 206 so that they can be energized in a distinguished state. Thus, the amount of heat generated in the axial direction of the heat generating layer 2033 can be adjusted by switching the energization state. That is, the heat generating member 203 can be adjusted so that the temperature distribution corresponding to the axial direction of the surface of the cylindrical portion 201a becomes a desired temperature distribution.

  For example, when the heating member 20 heats the fixing belt 25 that is a heating target, when the toner image 31 formed on the small-size recording paper 32 is fixed, the heating control unit 206 includes the cylindrical portion 201a. If energization control is performed by applying a voltage between the third power supply terminal portion 2033e and the fourth power supply terminal portion 2033f so that power is supplied only to the second resistance heating element 2033d arranged corresponding to the central portion in the axial direction. Good. Further, when fixing the toner image 31 formed on the large size recording paper 32, the heating control means 206 corresponds to the entire surface of the cylindrical portion 201a, and the first resistance heating element 2033a and the second resistance heating are generated. The energization control may be performed so that the body 2033d and the third resistance heating element 2033g are energized. In this way, the heat generating member 203 can be adjusted so that the temperature distribution corresponding to the axial direction of the surface of the cylindrical portion 201a becomes a desired temperature distribution even when the recording paper 32 having a different size is passed. .

  FIG. 4 is a diagram illustrating a configuration of a heat generating member 303 having another heat generation pattern. The heat generating member 303 is the same as the heat generating member 203 described above except that the structure of the heat generating layer 3033 is different. The heat generating layer 3033 is a layer made of a resistance heat generating element that generates Joule heat when energized. Like the heat generating layer 2033 of the heat generating member 203 described above, the heat generating layer 3033 corresponds to each of both ends in the axial direction of the cylindrical portion 201a. A heat generation region composed of a first resistance heating element 3033a and a heat generation region composed of a third resistance heat generation element 3033g are formed, and a heat generation region composed of a second resistance heat generation element 3033d corresponding to the central portion in the axial direction of the cylindrical portion 201a. Is formed.

  The first resistance heating element 3033a extends in the circumferential direction of the cylindrical portion 201a, and a plurality of linear portions 3043b formed on the surface of the third insulating layer 2034 in a substantially parallel state, and adjacent linear portions. And connecting portions 3043a formed on the surface of the third insulating layer 2034 by connecting the end portions in the extending direction of 3043b in the axial direction of the cylindrical portion 201a to form one line. Composed. Note that the connection portion 3043a and the linear portion 3043b are formed of the same material. And each of the both ends of the 1st resistance heating element 3033a is connected to the 1st electric power feeding terminal part 2033b and the 2nd electric power feeding terminal part 2033c.

  The second resistance heating element 3033d extends in the circumferential direction of the cylindrical portion 201a, and is adjacent to a plurality of linear portions 3043d formed on the surface of the third insulating layer 2034 in a substantially parallel state. The connecting portions 3043c formed on the surface of the third insulating layer 2034 by connecting the end portions of the extending portions 3043d in the axial direction of the cylindrical portion 201a so as to form one line. Consists of including. Note that the connection portion 3043c and the linear portion 3043d are formed of the same material. And each of the both ends of the 2nd resistance heating element 3033d is connected to the 3rd electric power feeding terminal part 2033e and the 4th electric power feeding terminal part 2033f.

  The third resistance heating element 3033g extends in the circumferential direction of the cylindrical portion 201a and is adjacent to a plurality of linear portions 3043f formed on the surface of the third insulating layer 2034 in a substantially parallel state. The connecting portions 3043e formed on the surface of the third insulating layer 2034 by connecting the ends of the extending portions 3043f in the axial direction of the cylindrical portion 201a so as to form one line. Consists of including. Note that the connection portion 3043e and the linear portion 3043f are formed of the same material. Then, both end portions of the third resistance heating element 3033g are connected to the fifth power supply terminal portion 2033h and the sixth power supply terminal portion 2033i, respectively.

  The second feeding terminal portion 2033c to which one end portion of the first resistance heating element 3033a is connected and the fifth feeding terminal portion 2033h to which one end portion of the third resistance heating body 3033g is connected are a lead wire 2033j. Connected through. Further, the first feeding terminal portion 2033b to which the other end portion of the first resistance heating element 3033a is connected and the sixth feeding terminal portion 2033i to which the other end portion of the third resistance heating body 3033g is connected are the heating control means 206. It is connected to the power supply via The third power supply terminal portion 2033e and the fourth power supply terminal portion 2033f to which each of the second resistance heating elements 3033d is connected are connected to a power source via the heating control means 206.

  A characteristic configuration of the first resistance heating element 3033a, the second resistance heating element 3033d, and the third resistance heating element 3033g having the connection structure as described above is such that the line widths of the connection portions 3043a, 3043c, and 3043e are linear. The widths of the portions 3043b, 3043d, and 3043f are wider, and the connection portion is configured to be a lower heat generation portion than the linear portion. The line widths of the connection portions 3043a, 3043c, and 3043e are preferably as large as possible. However, since the installation areas of the resistance heating elements 3033a, 3033d, and 3033g are limited, they may be optimized in the installation area. preferable.

In each of the resistance heating elements 3033a, 3033d, and 3033g serving as one line, a region portion where each of the connection portions 3043a, 3043c, and 3043e is formed becomes a bent portion. In the heat generating member 303 of the present embodiment, the connection portions 3043a, 3043c, and 3043e having a wider line width than the respective linear portions 3043b, 3043d, and 3043f are formed at the bent portions of the resistance heating elements 3033a, 3033d, and 3033g. Therefore, it is possible to prevent the current from being concentrated and flowing locally at the bent portion, and it is possible to prevent each of the resistance heating elements 3033a, 3033d, and 3033g from generating excessive heat locally. Therefore, it is possible to prevent the resistance heating elements 3033a, 3033d, and 3033g from locally peeling from the third insulating layer 2034 or being cut and broken.

FIG. 5 is a diagram illustrating a configuration of a heat generating member 403 having another heat generation pattern. The heat generating member 403 is the same as the heat generating member 203 described above except that the structure of the heat generating layer 4033 is different. The heat generating layer 4033 is a layer made of a resistance heating element that generates Joule heat when energized. Like the heat generating layer 2033 of the heat generating member 203 described above, the heat generating layer 4033 corresponds to each of both ends in the axial direction of the cylindrical portion 201a. A heat generation region composed of a first resistance heating element 4033a and a heat generation region composed of a third resistance heat generation element 4033g are formed, and a heat generation region composed of a second resistance heat generation element 4033d corresponding to the central portion in the axial direction of the cylindrical portion 201a. Is formed.

  The first resistance heating element 4033a is formed on the surface of the third insulating layer 2034, extending in the circumferential direction of the cylindrical portion 201a while being bent in a zigzag shape so that valleys and tops are alternately formed. A plurality of linear portions 4043b and end portions of adjacent linear portions 4043b extending in the axial direction of the cylindrical portion 201a are connected so as to form one line, and the third insulating layer 2034 is connected. And a connection portion 4043a formed on the surface. Note that the connection portion 4043a and the linear portion 4043b are formed with the same material and the same line width. And each of the both ends of the 1st resistance heating element 4033a is connected to the 1st electric power feeding terminal part 2033b and the 2nd electric power feeding terminal part 2033c.

  Further, the second resistance heating element 4033d is formed on the surface of the third insulating layer 2034 by extending in the circumferential direction of the cylindrical portion 201a while being bent in a zigzag shape so that valley portions and top portions are alternately formed. A plurality of linear portions 4043d to be connected to end portions in the extending direction of adjacent linear portions 4043d extending in the axial direction of the cylindrical portion 201a so as to form one line. And a connection portion 4043c formed on the surface of 2034. Note that the connection portion 4043c and the linear portion 4043d are formed of the same material and the same line width. And each of the both ends of the 2nd resistance heating element 4033d is connected to the 3rd electric power feeding terminal part 2033e and the 4th electric power feeding terminal part 2033f.

  Further, the third resistance heating element 4033g is formed on the surface of the third insulating layer 2034 by extending in the circumferential direction of the cylindrical portion 201a while being bent in a zigzag shape so that valley portions and top portions are alternately formed. A plurality of linear portions 4043f to be connected to end portions in the extending direction of adjacent linear portions 4043f extending in the axial direction of the cylindrical portion 201a so as to form one line. And a connecting portion 4043e formed on the surface of 2034. Note that the connection portion 4043e and the linear portion 4043f are formed of the same material and the same line width. Then, both end portions of the third resistance heating element 4033g are connected to the fifth power supply terminal portion 2033h and the sixth power supply terminal portion 2033i, respectively.

  The second feeding terminal portion 2033c to which one end portion of the first resistance heating element 4033a is connected and the fifth feeding terminal portion 2033h to which one end portion of the third resistance heating body 4033g is connected are the lead wire 2033j. Connected through. The first feeding terminal 2033b to which the other end of the first resistance heating element 4033a is connected and the sixth feeding terminal 2033i to which the other end of the third resistance heating element 4033g is connected are the heating control means 206. It is connected to the power supply via In addition, the third power supply terminal portion 2033e and the fourth power supply terminal portion 2033f to which each of the second resistance heating elements 4033d is connected are connected to a power source via the heating control means 206.

  In the present embodiment, as described above, the resistance heating elements 4033a, 4033d, and 4033g formed so as to form one line while being bent in a zigzag shape are configured to have uniform line widths. However, you may comprise so that the bending part of each resistance heating element may have a wide line | wire width.

  FIG. 6 is a block diagram showing an electrical configuration of the heating member 20. Energization of the heating member 20 to the heat generating members 203, 303, and 403 is controlled by the heating control means 206. Below, the case where the heating member 20 is provided with the heat generating member 203 is demonstrated. The heating control unit 206 includes a main control unit 2061, a detection unit 2062, a power calculation unit 2063, and a power supply control unit 2064. The main control unit 2061 comprehensively controls the detection unit 2062, the power calculation unit 2063, and the power supply control unit 2064. The main control unit 2061 may be configured by comprehensively controlling the detection unit 2062 and the power supply control unit 2064. The energization control for the heat generating member 203 in the heating control means 206 can include the following two energization control examples.

  In the first energization control example, the detection unit 2062 of the heating control unit 206 has a current value flowing through each of the resistance heating elements 2033a, 2033d, and 2033g that constitutes a heat generation region that is divided corresponding to the axial direction of the cylindrical portion 201a. And the voltage value applied to each electric power feeding terminal part is detected. The power calculation unit 2063 calculates the power value supplied to each resistance heating element 2033a, 2033d, 2033g based on the current value and the voltage value detected by the detection unit 2062. Then, based on the calculated power value calculated by the power calculation unit 2063, the power supply control unit 2064 causes each of the resistance heating elements 2033a, 2033d, and 2033g to generate heat within a predetermined temperature range that is set based on the set temperature. In addition, power supply to the resistance heating elements 2033a, 2033d, and 2033g is controlled.

  In the second energization control example, the detection unit 2062 of the heating control unit 206 includes each of the resistance heating elements 2033a, 2033d, and 2033g that constitute the heat generation region that is divided corresponding to the axial direction of the cylindrical portion 201a. A voltage value applied to the power supply terminal is detected. The power calculation unit 2063 calculates the power value supplied to each resistance heating element 2033a, 2033d, 2033g based on the voltage value detected by the detection unit 2062 and the electric resistance value of each resistance heating element 2033a, 2033d, 2033g. To do. Then, based on the calculated power value calculated by the power calculation unit 2063, the power supply control unit 2064 causes each of the resistance heating elements 2033a, 2033d, and 2033g to generate heat within a predetermined temperature range that is set based on the set temperature. In addition, power supply to the resistance heating elements 2033a, 2033d, and 2033g is controlled.

The heating control means 206 can also be configured by omitting the detection unit 2062. In this case, the power calculation unit 2063 calculates the power value supplied to each resistance heating element 2033a, 2033d, 2033g based on the detection result of the surface temperature of the heating object by a thermistor or the like. Then, based on the calculated power value calculated by the power calculation unit 2063, the power supply control unit 2064 causes each of the resistance heating elements 2033a, 2033d, and 2033g to generate heat within a predetermined temperature range that is set based on the set temperature. In addition, power supply to the resistance heating elements 2033a, 2033d, and 2033g is controlled.
The heating control means 206 can also be configured by omitting the power calculation unit 2063. The detection unit 2062 can also supply power to the resistance heating elements 2033a, 2033d, and 2033g based on the detection result of the surface temperature of the object to be heated by a thermistor or the like. In this case, the temperature can also be controlled by supplying power by cycle control, phase control, or the like.

  Next, the pressing member 204 will be described with reference to FIG. FIG. 7 is a diagram illustrating a configuration of the pressing member 204. The pressing member 204 is formed in a cylindrical shape that forms a part of a cylindrical body, contacts the inner peripheral surface of the heat generating members 203, 303, and 403 on the outer peripheral surface, and the heat generating members 203, 303, and 403 are connected to the cylinder of the heat radiating member 201. The heat generating members 203, 303, and 403 are held by elastically pressing in the direction close to the shape portion 201 a. Below, the case where the heating member 20 is provided with the heat generating member 203 is demonstrated.

  The pressing member 204 can be produced by cutting out a part of the cylindrical body in the circumferential direction, and the elevation angle with respect to the axial line at both ends in the circumferential direction of the pressing member 204 is the same as the elevation angle θ of the cylindrical portion 201a of the heat radiating member 201. The angle is selected from 180 ° to 320 °. Further, as the pressing member 204, for example, a pressing member 204a formed by bending a plate-like member as shown in FIG. 7A, or a pressing member formed in a mesh shape as shown in FIG. 7B 204b and the pressing member 204c in which the through-hole 2045 as shown in FIG.7 (c) is formed can be mentioned.

  A pressing member 204 a formed by bending a plate-like member as shown in FIG. 7A is provided curved in the circumferential direction of the heat generating member 203 so as to be along the inner peripheral surface of the heat generating member 203. The pressing member 204a does not have an opening that penetrates and opens in the thickness direction, and is formed by curving a plate-like member that is a solid plate. Since the pressing member 204 a is provided so as to be curved along the inner peripheral surface of the heat generating member 203, the restoring force that tries to return from the curved state to the stationary state causes the heat generating member 203 to move to the cylindrical portion 201 a of the heat radiating member 201. It acts as a force that elastically presses in the direction of approaching. Since such a restoring force acts to hold the heat generating member 203 on the inner peripheral surface of the cylindrical portion 201a, it is possible to stably hold the heat generating member 203 at a predetermined position on the inner peripheral surface of the cylindrical portion 201a. Can do.

  The pressing member 204b formed in a mesh shape shown in FIG. 7B has a plurality of extremely thin plate-like members 2041 having elastic force arranged at equal intervals in the axial direction, and having a plurality of elastic forces. The extremely thin plate-like members 2042 are formed in a mesh shape by being arranged at equal intervals in the circumferential direction perpendicular to the plurality of extremely thin plate-like members 2041. That is, the pressing member 204b formed in a mesh shape is configured such that a plurality of openings 2043 penetrating and opening in the thickness direction are regularly arranged at intervals. The pressing member 204b formed in a mesh shape as described above is provided to be curved in the circumferential direction of the heat generating member 203 so as to be along the inner peripheral surface of the heat generating member 203. The pressing member 204b is provided so as to be curved along the inner peripheral surface of the heat generating member 203, so that the restoring force to return the curved member to the stationary state causes the heat generating member 203 to be the cylindrical portion 201a of the heat radiating member 201. It acts as a force that elastically presses in the direction of approaching. Since such a restoring force acts to hold the heat generating member 203 on the inner peripheral surface of the cylindrical portion 201a, it is possible to stably hold the heat generating member 203 at a predetermined position on the inner peripheral surface of the cylindrical portion 201a. Can do.

  Further, the heating member 20 including the pressing member 204b configured to have the opening 2043 can suppress an increase in heat capacity. However, the pressing member 204b having the opening 2043 cannot apply a uniform pressing force over the entire inner peripheral surface of the heat generating member 203, and corresponds to a region where the resistance heating elements 2033a, 2033d, and 2033g are disposed. In some cases, sufficient pressing force is not applied to the inner peripheral surface portion of the heat generating member 203. As described above, in the region where the sufficient pressing force is not applied on the inner peripheral surface of the heat generating member 203, the heat transfer efficiency is lowered, and peeling / ignition due to abnormal overheating may occur.

  On the other hand, the minimum width dimension of the opening peripheral edge that defines each of the plurality of openings 2043 in the pressing member 204b, that is, the width dimension P2 of the extremely thin plate-like members 2041 and 2042 is the heat generation layer of the heat generation member 203. It is preferable that the line widths P1 of the linear portions 2043b, 2043d, and 2043f of the resistance heating elements 2033a, 2033d, and 2033g constituting the 2033 and the connection portions 2043a, 2043c, and 2043e are set to be equal to or larger than each other. Accordingly, the pressing member 204b can apply a sufficient pressing force to the inner peripheral surface portion of the heat generating member 203 corresponding to the region where the resistance heat generating elements 2033a, 2033d, and 2033g are disposed. Therefore, the region portion of the heat generating member 203 corresponding to the region where the resistance heating elements 2033a, 2033d, and 2033g are disposed is sufficiently in close contact with the inner peripheral surface of the heat radiating member 201, and local heat transfer efficiency is reduced. Can be suppressed. When the heating member 20 includes the heat generating member 403, the width dimension P2 of the pressing member 204b is the longitudinal dimension of the top (valley) of each linear portion 4043b, 4043d, 4043f formed in a zigzag shape. What is necessary is just to set so that it may become more than the line width of P4, trough part space | interval P5, the width dimension P6 of a trough part (top part), and a resistance heating element.

  In the pressing member 204c in which the through hole 2045 as shown in FIG. 7C is formed, a plurality of circular through holes 2045 are regularly spaced on the surface of a single plate-like member 2044 having elasticity. Is formed. The pressing member 204 c formed in the through hole 2045 as described above is provided curved in the circumferential direction of the heat generating member 203 so as to be along the inner peripheral surface of the heat generating member 203. The pressing member 204 c is provided so as to be curved along the inner peripheral surface of the heat generating member 203, so that the restoring force for returning from the curved state to the stationary state causes the heat generating member 203 to move to the cylindrical portion 201 a of the heat radiating member 201. It acts as a force that elastically presses in the direction of approaching. Since such a restoring force acts to hold the heat generating member 203 on the inner peripheral surface of the cylindrical portion 201a, it is possible to stably hold the heat generating member 203 at a predetermined position on the inner peripheral surface of the cylindrical portion 201a. Can do.

  Similarly to the pressing member 204b, the minimum width dimension P3 of the peripheral edge portion of the opening that defines each of the plurality of through holes 2045 in the pressing member 204c is the linear portions 2043b, 2043d, 2043f and the connecting portions 2043a, 2043c. , 2043e is preferably set to be equal to or larger than the line width P1. Accordingly, the pressing member 204c can apply a sufficient pressing force to the inner peripheral surface portion of the heat generating member 203 corresponding to the region where the resistance heat generating elements 2033a, 2033d, and 2033g are disposed. Therefore, the region portion of the heat generating member 203 corresponding to the region where the resistance heating elements 2033a, 2033d, and 2033g are disposed is sufficiently in close contact with the inner peripheral surface of the heat radiating member 201, and local heat transfer efficiency is reduced. Can be suppressed. When the heating member 20 includes the heat generating member 403, the width dimension P3 of the pressing member 204c is the longitudinal dimension of the top (valley) of each linear portion 4043b, 4043d, 4043f formed in a zigzag shape. What is necessary is just to set so that it may become more than the line width of P4, trough part space | interval P5, the width dimension P6 of a trough part (top part), and a resistance heating element.

  Further, the material constituting the pressing members 204a, 204b, 204c (hereinafter, the three types of pressing members are collectively referred to as “pressing member 204”) is not particularly limited, but a metal such as stainless steel or spring steel, polyimide, Examples thereof include a heat-resistant resin such as polyphenylene sulfide (PPS), a zirconia thin plate that is a bent ceramic that is not broken even when bent. The pressing member 204 made of such a material is a member having high strength and high toughness. Therefore, the pressing member 204 has high elasticity without being broken even if it is bent, and the heat generating member 203 is close to the heat radiating member 201. The force that elastically presses in the direction of movement increases. Therefore, the heat generating member 203 is fixed in a state in which the adhesion to the inner peripheral surface of the tubular portion 201a of the heat radiating member 201 is improved.

  Further, the pressing member 204 deforms a member having a radius of curvature R2 in the circumferential direction larger than the radius of curvature R1 in the circumferential direction of the cylindrical portion 201a of the heat radiating member 201, and is disposed inside the cylindrical portion 201a. It is preferable. As described above, by arranging the pressing member 204 disposed inside the heat dissipation member 201 in the heating member 20 in a deformed state, a force to restore the deformation acts on the pressing member 204, and this restoration is performed. The restoring force to be worked acts as a force that elastically presses the heat generating member 203 in the direction approaching the heat radiating member 201. As described above, the restoring force of the pressing member 204 acts to hold the heat generating member 203 on the inner peripheral surface of the heat radiating member 201, so that the heat generating member 203 has improved adhesion to the inner peripheral surface of the heat radiating member 201. It is fixed in the state that was done.

  In addition, the circumferential length of the pressing member 204 is set to be approximately equal to the circumferential length of the cylindrical portion 201a of the heat radiating member 201, but the axial length of the pressing member 204 is the cylinder of the heat radiating member 201. It is set so as to be larger than the lengths of the shape part 201a and the heat generating member 203 in the axial direction. And in this embodiment, the press member 204 is comprised so that it may have the extension part 2040 extended outward from the axial direction both ends of the cylindrical part 201a. Furthermore, each of the extending portions 2040 corresponding to each end portion is provided with a fixing adapter 205 configured to be connected to the outside and fix the pressing member 204.

  FIG. 8 is a diagram illustrating the configuration of the fixed adapter 205. The fixed adapter 205 provided in the extending portion 2040 of the pressing member 204 includes a frame connection portion 205a, a connection hole 205b, a pressing member support portion 205c, and an adapter opening portion 205d. The fixed adapter 205 is made of a metal such as aluminum, for example. The shape of the fixed adapter 205 is not particularly limited, but in this embodiment, the pressing member support portion 205c is formed in a substantially cylindrical shape.

  The pressing member support portion 205c is formed with an adapter opening portion 205d that penetrates and opens in the thickness direction so that the extension portion 2040 of the pressing member 204 can be inserted. The frame connection portion 205a is formed so as to protrude outward from a part of the side surface of the pressing member support portion 205c, and the frame connection portion 205a is formed with a connection hole 205b penetrating and opening in the thickness direction. ing.

  The fixed adapter 205 is connected to an external member through a screw member or the like inserted into a connection hole 205b formed in the frame connection portion 205a in a state where the extension portion 2040 of the pressing member 204 is inserted into the adapter opening portion 205d. By being connected, the pressing member 204 is fixed to an external member. Thus, by fixing the pressing member 204 to an external member via the fixing adapter 205 provided in the extending portion 2040, the arrangement position of the pressing member 204 with respect to the heat generating member 203 is regulated. Then, by restricting the arrangement position of the pressing member 204, the external force due to the restriction can be applied as a pressing force that elastically presses the heat generating member 203 in the direction approaching the heat radiating member 201. Therefore, the pressing member 204 can stably hold the heat generating member 203 at a predetermined position on the inner peripheral surface of the heat radiating member 201.

  As described above, the heating member 20 of the present embodiment includes the heat dissipation member 201, the low hardness and good heat conduction member 202 disposed in contact with the inner peripheral surface of the heat dissipation member 201, and the low hardness and good heat conduction member 202. The heat generating member 203 is disposed in contact with the inner peripheral surface, and the pressing member 204 is configured to elastically press the heat generating member 203 in a direction close to the heat radiating member 201. The heat generating member 203 is pressed by the pressing member 204 in the direction approaching the heat radiating member 201 and is fixed to the inner peripheral surface of the heat radiating member 201. Therefore, the heat generating member 203 is fixed in a state where the adhesion to the inner peripheral surface of the heat radiating member 201 is improved. Furthermore, since the low-hardness heat-conductive member 202 made of a material having low hardness and high thermal conductivity is disposed between the heat-dissipating member 201 and the heat-generating member 203, Without reducing the heat transfer efficiency, the difference in thermal expansion of each member constituting the heating member 20 can be absorbed and relaxed, and local separation between the members can be prevented.

  As described above, the heating member 20 of the present embodiment is maintained in a state in which the heat generating member 203 is highly adhered to the inner peripheral surface of the heat radiating member 201, and local peeling occurs between the members. Therefore, the local heat transfer efficiency is prevented from being lowered, and the surface temperature distribution becomes a heating member having no variation with respect to the set temperature. Therefore, the heating member 20 can ensure a short warm-up time until reaching the set temperature and a uniform temperature distribution on the surface in a short time, and a sufficient amount of heat can be obtained from the heat radiating member 201 even in high-speed printing. It can be supplied to the fixing belt 25 that is the object to be heated.

  FIG. 9 is a diagram showing a configuration of the heating member 30 according to the second embodiment of the present invention. The heating member 30 of the present embodiment is similar to the heating member 20 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. The heating member 30 is the same as the heating member 20 except that the heat dissipation member 201 included in the heating member 20 described above is replaced with a heat dissipation member 301. A characteristic configuration of the heating member 30 is that an inner surface coating layer 3013 is formed on the inner peripheral surface of the tubular portion 301a of the heat radiating member 301 and an outer surface coating layer 3014 is formed on the outer peripheral surface.

  The inner coat layer 3013 is made of a material having heat resistance and high heat radiation (for example, a material having an emissivity of 0.9 to 1.0 in a wide wavelength region and having heat resistance). The heat dissipating member 301 in which the inner surface coating layer 3013 made of a material having heat resistance and high heat radiation is formed on the inner peripheral surface of the cylindrical portion 301a absorbs and dissipates heat generated by the heat generating member 203 with high efficiency. Heat can be transferred with high efficiency to the fixing belt 25 which is a heating object.

  Examples of the material having heat resistance and high heat radiation property include silicone resins. The inner surface coat layer 3013 can be formed, for example, by spraying a liquid material in which the material is dissolved or dispersed in a solvent on the inner peripheral surface of the cylindrical portion 301a. Specifically, the inner surface coat layer 3013 can be formed by spray-coating B-600 manufactured by Okitsumo Co., Ltd., which is a material made of a silicone resin, on the inner peripheral surface of the cylindrical portion 301a. As described above, by forming the inner surface coat layer 3013 on the inner peripheral surface of the cylindrical portion 301a that is in contact with the low-hardness and high-heat conductive member 202, at the interface between the cylindrical portion 301a and the low-hardness and high-heat conductive member 202. Corrosion can be prevented from occurring, and a decrease in heat transfer efficiency from the heat generating member 203 to the heat radiating member 301 can be prevented over a long period of time.

  The outer surface coat layer 3014 is made of a material having heat resistance and a low friction coefficient. Examples of the material having heat resistance and a low friction coefficient include fluororesins such as PFA (a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) and PTFE (polytetrafluoroethylene). These fluororesins May be used alone or in combination of two or more.

As described above, the outer surface coating layer 3014 is formed on the outer peripheral surface of the cylindrical portion 301a with which the fixing belt 25 as the heating object contacts, thereby reducing the frictional force between the cylindrical portion 301a and the fixing belt 25. It is possible to prevent the fixing belt 25 from being worn, to ensure high durability of the fixing belt 25, and to load the fixing roller 15a and the pressure roller 15b for driving the fixing belt 25 to rotate. In addition, the high durability of each roller can be secured, and the roller can be driven to rotate with low power. Further, when the frictional force between the cylindrical portion 301a and the fixing belt 25 can be reduced, the rotation of the fixing belt 25 can be made smooth, and the heat transfer efficiency of the heating member 30 to the fixing belt 25 is reduced. Can be prevented.
FIG. 10 is a diagram showing a configuration of a heating member 30A that is the third embodiment of the present invention. The heating member 30A of the present embodiment is similar to the heating member 20 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. The heating member 30 </ b> A is the same as the heating member 20 except that the heat dissipation member 201 included in the heating member 20 described above is replaced with a heat dissipation member 302. The heat radiating member 302 included in the heating member 30A includes a cylindrical portion 302a that is formed in a cylindrical shape that forms a part of a cylindrical body, and a bent piece 302b that is bent inward from at least a portion of both circumferential ends of the cylindrical portion 302a. Have The bent piece 201b of the heat radiating member 201 has two bent portions 2011 and 2012, whereas the bent piece 302b of the heat radiating member 302 is configured to have only one first bent portion 3021.

  The first bent portion 3021 of the bent piece 302b is bent in a direction approaching the pressing member 204 from at least a part of both ends in the circumferential direction of the cylindrical portion 302a, and the free end portion is in contact with the inner peripheral surface of the pressing member 204. The pressing member 204 is formed so as to apply a pressing force in a direction close to the heat generating member 203.

  In the heating member 30 </ b> A of the present embodiment, the heat generating member 203 is pressed by the pressing member 204 in the direction approaching the heat radiating member 302 and is fixed to the inner peripheral surface of the heat radiating member 302. Since the pressing force is applied in the direction approaching the heat generating member 203 by the bent portion 3021, the pressing force acts as a force for pressing the heat generating member 203 in the direction approaching the heat radiating member 302. Accordingly, the heat generating member 203 is fixed in a state in which the adhesion to the inner peripheral surface of the heat radiating member 302 is improved.

  FIG. 11 is a diagram illustrating a configuration of the fixing device 15 according to the embodiment of the present invention. FIG. 12 is a diagram illustrating the configuration of the fixing device 15 in the vicinity of a region where the fixing belt is suspended from the heating member. The fixing device 15 is a device provided in the image forming apparatus 100 described later, and is a device that heats and presses the toner image 31 carried on the recording paper 32 that is a recording medium and fixes the toner image 31 on the recording paper 32. . The fixing device 15 includes any one of the heating members 20, 30, and 30A of the present embodiment described above. A case where the fixing device 15 includes the heating member 20 will be described below.

  The fixing device 15 includes a fixing roller 15 a that is a first fixing member, a pressure roller 15 b that is a second fixing member, a fixing belt 25 that is an endless belt, and a heating member 20. In the fixing device 15, the fixing belt 25 is stretched between the fixing roller 15 a and the heating member 20, and the pressure roller 15 b is disposed so as to face the fixing roller 15 a through the fixing belt 25. The fixing roller 15a and the heating member 20 are arranged so as to be substantially parallel in the axial direction of the fixing roller 15a. That is, the axis of the fixing roller 15a and the axis of the heating member 20 are substantially parallel. Thus, when the fixing belt 25 stretched between the fixing roller 15a and the heating member 20 slides, it can be prevented from meandering, and the durability of the fixing belt 25 can be maintained high.

  In the fixing device 15, the heating member 20 contacts the fixing belt 25 to heat the fixing belt 25, and the fixing nip portion 15c formed by the fixing belt 25 and the pressure roller 15b is recorded at a predetermined fixing speed and copying speed. This is an apparatus for fixing an unfixed toner image 31 carried on the recording paper 32 by heating and pressing the recording paper 32 when the recording paper 32 as a medium passes.

  The unfixed toner image 31 is a developer (such as a non-magnetic one-component developer (non-magnetic toner), a non-magnetic two-component developer (non-magnetic toner and carrier), or a magnetic developer (magnetic toner). Toner). The fixing speed is a so-called process speed, and the copying speed is the number of copies per minute. When the recording paper 32 passes through the fixing nip portion 15c, the fixing belt 25 comes into contact with the surface of the recording paper 32 opposite to the toner image carrying surface.

  The fixing roller 15a is pressed against the pressure roller 15b via the fixing belt 25 to form a fixing nip portion 15c, and is driven to rotate in the rotation direction A around the rotation axis by a drive motor (driving means) 113. Thus, the fixing belt 25 is conveyed. The fixing roller 15a has a diameter of 30 mm and has a two-layer structure in which a core metal and an elastic layer are formed in order from the inside. The core metal includes, for example, a metal such as iron, stainless steel, aluminum, copper, or the like. An alloy or the like is used. For the elastic layer, a heat-resistant rubber material such as silicon rubber or fluorine rubber is suitable. In the present embodiment, the force when the fixing roller 15a is pressed against the pressure roller 15b via the fixing belt 25 is about 216N.

  The pressure roller 15b is opposed to and pressed against the fixing roller 15a via the fixing belt 25, and is provided to be rotatable about the rotation axis. The pressure roller 15b rotates in the rotation direction B following the rotation of the fixing roller 15a. The pressure roller 15b has a three-layer structure in which a metal core, an elastic layer, and a release layer are formed in this order from the inside. For the core metal, for example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof is used. In addition, a rubber material having heat resistance such as silicon rubber and fluorine rubber is suitable for the elastic layer, and a fluorine resin such as PFA and PTFE is suitable for the release layer. The pressure roller 15b has, for example, a roller diameter of 30 mm, a core (STKM) pipe with a diameter of 24 mm (wall thickness 2 mm), a silicon solid rubber with a thickness of 3 mm as an elastic layer, and a thickness of 30 μm as a release layer. A roller made of a PFA tube can be used.

  A heater lamp 26 (for example, rated power 400 W) for heating the pressure roller 15b is disposed inside the pressure roller 15b. The apparatus control means 111 described later supplies power to the heater lamp 26 from the power supply circuit 1111 (energization), whereby the heater lamp 26 emits light, and infrared light is emitted from the heater lamp 26. As a result, the inner peripheral surface of the pressure roller 15b is heated by absorbing infrared rays, and the entire pressure roller 15b is heated. The above-described heater lamp 26 is heated from the inner surface of the pressure roller 15b. Alternatively, a method of heating from the surface of the pressure roller 15b with an outer peripheral surface heating roller can be configured. is there.

  The fixing belt 25 is heated to a predetermined temperature by the heating member 20 and heats the recording paper 32 on which the unfixed toner image 31 that passes through the fixing nip portion 15c is formed. The fixing belt 25 is an endless belt, is suspended by the heating member 20 and the fixing roller 15a, and is wound around the fixing roller 15a at a predetermined angle. When the fixing roller 15a rotates, the fixing belt 25 follows the fixing roller 15a and rotates in the rotation direction A. The fixing belt 25 is formed of an elastomer material (for example, silicon rubber) having excellent heat resistance and elasticity as an elastic layer on the surface of a hollow cylindrical base material made of a heat resistant resin such as polyimide or a metal material such as stainless steel or nickel. Furthermore, the surface has a three-layer structure in which a synthetic resin material (for example, a fluororesin such as PFA or PTFE) having excellent heat resistance and releasability is formed on the surface as a release layer. Moreover, you may add a fluororesin internally to the polyimide of a base material. Thereby, the sliding load with the heating member 20 can be reduced.

  The heating member 20 provided in the fixing device 15 contacts the fixing belt 25 on the outer peripheral surface of the cylindrical portion 201a of the heat radiating member 201 to heat the fixing belt 25 to a predetermined temperature. As described above, the heating member 20 included in the fixing device 15 includes the heat radiating member 201, the low-hardness and good heat conducting member 202, and the heat generating region divided into three axial ends and a central portion of the heat radiating member 201. A member 203 and a pressing member 204 are included.

  Two fixing adapters 205 are provided in the extending portions 2040 provided at both ends of the pressing member 204 in the axial direction so as to correspond to the respective ends, and the pressing member 204 is connected to the fixing device 15 via the fixing adapter 205. The side frame 110 is fixed. As described above, since the pressing member 204 is fixed to the side frame 110 via the fixed adapter 205, the heating member 20 itself is prevented from rotating due to frictional force with the fixing belt 25. Therefore, even if a high current is supplied to the heat generating member 203 included in the heating member 20, safety can be sufficiently ensured. Furthermore, since the pressing member 204 is fixed to the side frame 110 via the fixed adapter 205, the arrangement position of the pressing member 204 with respect to the heat generating member 203 is restricted. In this way, by restricting the arrangement position of the pressing member 204, external force (belt tension acting between the fixing belt 25 and the pressing member 204) due to the restriction is used to bring the heat generating member 203 close to the heat radiating member 201. It can be applied as a pressing force that elastically presses in the direction.

  Further, the fixing device 15 may be configured such that a meandering prevention collar that prevents meandering when the fixing belt 25 rotates and slides is provided in the extending portion 2040 of the pressing member 204. As the collar for preventing meandering, a color made of polyphenylene sulfide (PPS) can be used, but the collar is not limited to this, and any collar that can rotate independently from the extending portion 2040 of the pressing member 204 can be used. Good. Thus, since the meandering prevention collar is independently rotatable, even if the fixing belt 25 abuts on the meandering prevention collar, no load is applied and the fixing belt 25 is prevented from being broken. Thus, the durability of the fixing belt 25 can be maintained high. Depending on the rotation state of the fixing belt 25, the meandering prevention collar may be provided only on the fixing roller 15a without the meandering prevention collar being provided on the extending portion 2040.

  Further, in the fixing device 15, as temperature detection means, a heating element side thermistor 24 a is provided in the vicinity of the peripheral surface of the fixing belt 25 that contacts the heating member 20, and a pressure roller side thermistor 24 b is provided in the vicinity of the peripheral surface of the pressure roller 15 b. Each surface temperature is detected. The heating element side thermistor 24a in the present embodiment is a non-contact type temperature detection means, and is an infrared detection type temperature sensor. In the configuration in which the contact-type temperature detection unit is arranged in contact with the fixing belt 25, the contact-type temperature detection unit may wear the surface release layer of the fixing belt 25 at the interface in contact with the fixing belt 25. When the surface release layer of the fixing belt 25 is damaged or deteriorated in this manner, the fixing property with respect to the toner image 31 is affected, and an inferior fixed image is formed on the recording paper 32. In the vicinity of the peripheral surface of the fixing belt 25, a thermostat or a thermal protector 24c that detects an abnormal temperature rise of the fixing belt 25 and cuts off the power supply circuit 1111 when the temperature exceeds a predetermined temperature is provided.

  Next, electrical control in the fixing device 15 will be described. FIG. 13 is a block diagram showing an electrical configuration of the fixing device 15. In the fixing device 15, a control circuit 1112 as temperature control means is based on temperature data detected by the heating element side thermistor 24 a and pressure roller side thermistor 24 b and abnormal temperature rise data of the fixing belt 25 detected by the thermal protector 24 c. However, the power supply to the heat generating member 203 and the heater lamp 26 included in the heating member 20 is controlled via the power supply circuit 1111 so that the surface temperatures of the fixing belt 25 and the pressure roller 15b are set to predetermined temperatures. In addition, the control circuit 1112 controls the drive motor 113 to rotate the fixing roller 15a around the rotation axis and rotate the fixing belt 25. The control circuit 1112 and the power supply circuit 1111 are comprehensively controlled by a device control unit 111 that controls all operations of the fixing device 15.

  Specifically, when receiving an image formation instruction, the apparatus control unit 111 outputs a control signal instructing the power supply circuit 1111 to supply power. Here, the image forming instruction is an instruction input from an operation panel provided on the upper surface in the vertical direction of the image forming apparatus 100, which will be described later, or an external device such as a computer connected to the image forming apparatus 100. By receiving the input, the fixing device 15 starts the fixing processing operation.

  The power supply circuit 1111 to which the control signal is input from the apparatus control unit 111 supplies power to the heat generating member 203 of the heating member 20 through the heating control unit 206 to heat the fixing belt 25, and supplies power to the heater lamp 26. Supply and heat the pressure roller 15b. A signal related to the surface temperature data of the fixing belt 25 detected by the heating element side thermistor 24a, a signal related to the surface temperature data of the pressure roller 15b detected by the pressure roller side thermistor 24b, and an abnormal temperature rise of the fixing belt 25 detected by the thermal protector 24c. A signal related to data is input to the control circuit 1112.

  The control circuit 1112 controlled by the device control means 111 is supplied from the power supply circuit 1111 so that the surface temperature of the fixing belt 25 and the pressure roller 15b becomes a predetermined temperature (fixing temperature) based on the input signal. The power supplied to the heating member 20 and the heater lamp 26 is controlled. Specifically, the heating control means 206 controlled by the power supply circuit 1111 is based on the temperature data detected by the heating element side thermistor 24a or based on the temperature data and the calculated power value calculated by the power calculation unit 2063. Thus, the power supplied to the heating member 20 is controlled. The power supply circuit 1111 controls the power supplied to the heater lamp 26 based on the temperature data detected by the pressure roller side thermistor 24b.

  When the control circuit 1112 determines that the surface temperature of the fixing belt 25 and the pressure roller 15b has reached a predetermined fixing temperature based on the input signal, the control circuit 1112 controls the drive motor 113 to move the fixing roller 15a around the rotation axis. And the fixing belt 25 is rotated. When the fixing belt 25 rotates in this way, the recording paper 32 on which the unfixed toner image 31 is formed is conveyed to the fixing nip portion 15c formed between the fixing belt 25 and the pressure roller 15b. At this time, the recording paper 32 is conveyed with the surface carrying the unfixed toner image 31 facing the fixing belt 25 side. The unfixed toner image 31 on the recording paper 32 is nipped and conveyed while being in close contact with the outer peripheral surface of the fixing belt 25, whereby heat is applied from the fixing belt 25 and the recording paper 32 is subjected to pressure. To be fixed on the surface.

  The fixing device 15 configured as described above includes the heating member 20 of the present embodiment in which the temperature distribution on the surface does not vary with respect to the set temperature, so that the temperature distribution on the surface of the fixing belt 25 becomes the set temperature. On the other hand, the fixing device is uniform and the fixing temperature is prevented from varying, and the fixing device has uniform fixing characteristics. Further, since the heating member 20 of the present embodiment provided in the fixing device 15 is one in which a local decrease in heat transfer efficiency is prevented, the fixing device 15 has a warm-up time until a desired fixing temperature is obtained. And a fixing device in which an increase in power consumption is prevented.

  In the present embodiment, the fixing device 15 is configured such that the fixing nip portion 15c is formed at the pressure contact portion where the pressure roller 15b is in pressure contact with the fixing roller 15a via the fixing belt 25. The fixing nip portion may be formed at a pressure contact portion 15b in pressure contact with the heating member 20 via the fixing belt 25.

  FIG. 14 is a diagram illustrating a configuration of a fixing device 40 according to another embodiment of the present invention. In the fixing device 40, a first fixing unit 450 disposed on the upstream side in the transport direction of the recording paper 32 carrying the unfixed toner image 31 and a second fixing unit 460 disposed on the downstream side in the transport direction are vertically arranged. It is configured to be arranged side by side in the direction. A guide member such as a conveyance guide plate or a conveyance roller is provided between the first fixing unit 450 and the second fixing unit 460, and the recording paper 32 fixed at the fixing nip portion of the first fixing unit 450. Is conveyed along the guide member, fixed at the fixing nip portion of the second fixing unit 460, and discharged. The fixing device 40 can be mounted on an image forming apparatus 100 described later instead of the fixing device 15. Each of the first fixing unit 450 and the second fixing unit 460 included in the fixing device 40 includes any one of the heating members 20, 30, and 30A of the present embodiment described above. The case where each of the first fixing unit 450 and the second fixing unit 460 includes the heating member 20 will be described below.

  The first fixing unit 450 includes the heating member 20, the first fixing roller 452, the first pressure roller 453, and the first fixing belt 454 configured similarly to the fixing belt 25 described above. . In the first fixing unit 450, the first fixing belt 454 is stretched between the first fixing roller 452 and the heating member 20, and the first pressure roller 453 is interposed between the first fixing belt 454 and the first fixing roller. 452 is arranged to face 452.

  As described above, the heating member 20 included in the first fixing unit 450 is divided into the heat radiating member 201, the low-hardness and high-heat conducting member 202, and the heat generating region into the axial end portions and the central portion of the heat radiating member 201. The heating member 203 and the pressing member 204 are included. Further, a fixed adapter 205 is provided on the extending portion 2040 of the pressing member 204, and the pressing member 204 is fixed to the side frame of the fixing device 40 via the fixed adapter 205.

  In the present embodiment, the cylindrical portion 201a of the heat radiating member 201 is notched partially in the circumferential direction of a cylindrical body made of aluminum having a thickness of 0.5 mm, the curvature radius R1 is 20 mm (diameter 40 mm), and the circumferential direction The elevation angle θ with respect to the axis of both ends is made to be 235 ° (the narrow angle is 125 °). The heat generated by the heat generating member 203 comes into contact with the first fixing belt 454 on the outer peripheral surface. 1 is transmitted to the fixing belt 454.

  As described above, in the heat generating member 203, the heat generating region is divided into three parts corresponding to both the axial end portions and the central portion of the heat radiating member 201, and each heat generating region can be energized in a distinguished state. ing. The heat generating member 203 generates heat by appropriately controlling energization of each heat generating area according to the paper passing size and thickness of the recording paper 32 to be passed. In the present embodiment, the heat generating member 203 generates heat with a heat generation amount of 1100 W, the central portion is 600 W, and both axial ends are 250 W. Instead of the heat generating member 203, the heat generating member 303 described above may be used.

  Further, a first heating element side thermistor 455 that detects the temperature of the peripheral surface in a non-contact manner is disposed in the vicinity of the peripheral surface of the first fixing belt 454 wound around the heating member 20.

  The first fixing roller 452 is pressed against the first pressure roller 453 via the first fixing belt 454 to form a fixing nip portion, and is driven to rotate in the rotation direction G around the rotation axis by the drive motor 113. As a result, the first fixing belt 454 is conveyed. The first fixing roller 452 has a two-layer structure in which a cored bar 452a and an elastic layer 452b are formed in order from the inside. The cored bar 452a includes, for example, a metal such as iron, stainless steel, aluminum, copper, or the like. An alloy or the like is used, and in this embodiment, the cored bar 452a is a member made of aluminum and having an outer diameter of 40 mm. In addition, a rubber material having heat resistance such as silicon rubber or fluororubber is suitable for the elastic layer 452b. In this embodiment, the elastic layer 452b is a member having a thickness of 5 mm made of a silicon foam sponge having a low thermal conductivity. It is. The surface hardness of the first fixing roller 452 thus configured is 68 degrees (Asker C hardness).

  Further, in the vicinity of the peripheral surface of the first fixing belt 454 where the first fixing belt 454 is wound (heating nip portion), the peripheral surface temperature of the first fixing belt 454 wound around the first fixing roller 452 is not set. A first fixing roller side thermistor 456 that detects by contact is disposed.

  The first pressure roller 453 faces the first fixing roller 452 via the first fixing belt 454 and is in pressure contact with the first fixing roller 454. The first pressure roller 453 is provided to be rotationally driven around the rotation axis in the rotation direction H by a drive motor (not shown). Yes. The first fixing belt 454 and the first fixing roller 452 and the first pressure roller 453 rotate in opposite directions. The first pressure roller 453 has a three-layer structure in which a core metal 453a, an elastic layer 453b, and a release layer 453c are formed in that order from the inside. For example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof is used for the core metal 453a. In this embodiment, the core metal 453a is a member made of aluminum and having an outer diameter of 46 mm. In addition, a rubber material having heat resistance such as silicon rubber or fluororubber is suitable for the elastic layer 453b. In this embodiment, the elastic layer 453b is a member made of silicon rubber and having a thickness of 2 mm. Further, a fluororesin such as PFA or PTFE is suitable for the release layer 453c. In this embodiment, the release layer 453c is a member made of PFA and having a thickness of about 30 μm. The surface pressure of the first pressure roller 453 thus configured is 75 degrees (Asker C hardness).

  In addition, a first heater lamp 453d (for example, rated power 450 W) for heating the first pressure roller 453 is disposed inside the first pressure roller 453. When the apparatus control means 111 supplies (energizes) power from the power supply circuit 1111 to the first heater lamp 453d, the first heater lamp 453d emits light, and infrared light is emitted from the first heater lamp 453d. As a result, the inner peripheral surface of the first pressure roller 453 is heated by absorbing infrared rays, and the entire first pressure roller 453 is heated. Further, a first pressure roller side thermistor 457 that detects the surface temperature of the first pressure roller 453 by contact is disposed on the circumferential surface of the first pressure roller 453. The first pressure roller 453 may be provided with an external heating device that quickly heats the surface of the first pressure roller 453, a cleaning roller, and an oil application roller.

  The first fixing roller 452 and the first pressure roller 453 have an outer diameter of 50 mm and are pressed against each other with a predetermined load (600 N in this case) by an elastic member (spring member) (not shown). As a result, a fixing nip portion is formed between the circumferential surface of the first fixing belt 454 and the circumferential surface of the first pressure roller 453 that spans the first fixing roller 452 and the first heating unit 451. The fixing nip portion is a portion where the first fixing belt 454 and the first pressure roller 453 are in contact with each other, and is 9 mm in the present embodiment. The first fixing roller 452 is heated to a predetermined temperature (here, 180 ° C.), and the recording paper 32 passes through the fixing nip portion, whereby the unfixed toner image 31 is heated and melted to fix the image. It is like that. When the recording paper 32 passes through the fixing nip portion, the first fixing belt 454 contacts the toner image forming surface of the recording paper 32, while the first pressure roller 453 is opposite to the toner image forming surface of the recording paper 32. It comes in contact with the surface.

  The recording paper 32 is conveyed to the fixing nip portion at a predetermined fixing speed and copying speed according to the rotation speeds of the first fixing roller 452 and the first pressure roller 453, and the unfixed toner image 31 is transferred to the recording paper 32. It is fixed by heat and pressure. Here, the fixing speed is a so-called process speed. For example, when monochrome printing is performed, the fixing speed is 355 mm / sec. When color printing is performed, the rotation speed is 220 mm / sec. The copying speed is 1 minute. For example, it is 70 sheets / minute for monochrome printing and 60 sheets / minute for color printing.

  The first fixing unit 450 is provided with a web cleaning device (not shown) that cleans the surface of the first fixing belt 454.

  In addition, the fixing device 40 includes the device control unit 111 as in the above-described fixing device 15, and the control circuit 1112 of the device control unit 111 is based on the temperature data detected by the thermistors 455, 456, and 457. Then, the heating member 206 is controlled via the power supply circuit 1111 so that the heat radiating member 201, the first fixing belt 454, and the first pressure roller 453 included in the heating member 20 have predetermined temperatures. And energization to the 1st heater lamp 453d is controlled.

  Next, the second fixing unit 460 will be described. The second fixing unit 460 includes the heating member 20, the second fixing roller 462, the second pressure roller 463, and the second fixing belt 464 configured similarly to the fixing belt 25 described above. . In the second fixing unit 460, the second fixing belt 464 is stretched between the second fixing roller 462 and the heating member 20, and the second pressure roller 463 is interposed between the second fixing belt 464 and the second fixing roller. It arrange | positions so that 462 may be opposed. The basic configuration of the second fixing unit 460 is the same as that of the first fixing unit 450, but the configuration of the heating member 20 and the configuration of the second fixing roller 462 are different.

  The heating member 20 provided in the second fixing unit 460 is divided into three parts corresponding to the heat radiation member 201, the low hardness and good heat conduction member 202, and the heat radiation region at both axial ends and the center of the heat radiation member 201, In addition, the heat generating member 203 is divided into two parts corresponding to the circumferential direction of the heat radiating member 201, and the pressing member 204 is divided into six parts. Further, a fixed adapter 205 is provided on the extending portion 2040 of the pressing member 204, and the pressing member 204 is fixed to the side frame of the fixing device 40 via the fixed adapter 205.

  The heat radiating member 201 is in contact with the second fixing belt 464 on the outer peripheral surface, and transfers heat generated by the heat generating member 203 to the second fixing belt 464.

  In the heating member 20 provided in the second fixing unit 460, the heat generating member 203 is divided into three corresponding to the axial direction both ends and the central portion of the heat radiating member 201, and the heat generating member 203 extends in the circumferential direction of the heat radiating member 201. Correspondingly, it is divided into two parts, and the respective heat generation areas divided into six parts in total can be energized in a distinguished state. The heat generating member 203 generates heat by appropriately controlling energization of each heat generating area according to the paper passing size and thickness of the recording paper 32 to be passed. In the present embodiment, the heating member 20 provided in the second fixing unit 460 generates heat with a heat generation amount of 900 W, the total of the two heat generation areas in the center is 600 W, and the total of the four heat generation areas at both ends in the axial direction is the total. 300W.

  In addition, a second heating element side thermistor 465 is disposed in the vicinity of the peripheral surface of the second fixing belt 464 wound around the heating member 20 to detect the peripheral surface temperature in a non-contact manner.

  The second fixing roller 462 is pressed against the second pressure roller 463 via the second fixing belt 464 to form a fixing nip portion, and is driven to rotate in the rotation direction I around the rotation axis by a drive motor (not shown). As a result, the second fixing belt 464 is conveyed. The second fixing roller 462 has a two-layer structure in which a core metal 462a and an elastic layer 462b are formed in order from the inside. The core metal 462a includes, for example, a metal such as iron, stainless steel, aluminum, copper, or the like. An alloy or the like is used. In this embodiment, the cored bar 462a is a member made of aluminum and having an outer diameter of 46 mm. In addition, a heat-resistant rubber material such as silicon rubber or fluorine rubber is suitable for the elastic layer 462b. In this embodiment, the elastic layer 462b is a member made of silicon rubber and having a thickness of 2 mm. The surface hardness of the second fixing roller 462 thus configured is 68 degrees (Asker C hardness).

  In addition, the peripheral surface temperature of the second fixing belt 464 wound around the second fixing roller 462 is not contacted in the vicinity of the peripheral surface of the portion where the second fixing belt 464 is wound (heating nip portion) of the second fixing roller 462. A second fixing roller-side thermistor 466 that is detected by the above is disposed.

  The second pressure roller 463 faces the second fixing roller 462 via the second fixing belt 464 and is in pressure contact therewith, and is driven to rotate around the rotation axis in the rotation direction J by the drive motor 113. . The second fixing belt 464, the second fixing roller 462, and the second pressure roller 463 rotate in directions opposite to each other. The second pressure roller 463 has a three-layer structure in which a core metal 463a, an elastic layer 463b, and a release layer 463c are formed in order from the inside. For example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof is used for the core metal 463a. In this embodiment, the core metal 463a is a member made of aluminum and having an outer diameter of 46 mm. In addition, a rubber material having heat resistance such as silicon rubber and fluorine rubber is suitable for the elastic layer 463b. In this embodiment, the elastic layer 463b is a member made of silicon rubber and having a thickness of 2 mm. In addition, a fluororesin such as PFA or PTFE is suitable for the release layer 463c. In this embodiment, the release layer 463c is a member made of PFA and having a thickness of about 30 μm. The surface pressure of the second pressure roller 463 thus configured is 75 degrees (Asker C hardness).

  Further, a second heater lamp 463d (for example, rated power 400 W) for heating the second pressure roller 463 is disposed inside the second pressure roller 463. When the apparatus control unit 111 supplies (energizes) power from the power supply circuit 1111 to the second heater lamp 463d, the second heater lamp 463d emits light, and infrared rays are emitted from the second heater lamp 463d. As a result, the inner peripheral surface of the second pressure roller 463 is heated by absorbing infrared rays, and the entire second pressure roller 463 is heated. In addition, a second pressure roller side thermistor 467 that detects the surface temperature of the second pressure roller 463 by contact is disposed on the peripheral surface of the second pressure roller 463.

  The second fixing roller 462 and the second pressure roller 463 have an outer diameter of 50 mm, and are pressed against each other with a predetermined load (here, 550 N) by an elastic member (spring member) (not shown). As a result, a fixing nip portion is formed between the peripheral surface of the second fixing belt 464 and the peripheral surface of the second pressure roller 463 that are stretched over the second fixing roller 462 and the second heating unit 461. The fixing nip portion is a portion where the second fixing belt 464 and the second pressure roller 463 come into contact with each other, and is 8 mm in the present embodiment.

  Based on the temperature data detected by the thermistors 465, 466, and 467, the control circuit 1112 of the apparatus control unit 111 is configured so that the heat radiation member 201, the second fixing belt 464, and the second pressure roller 463 included in the heating member 20 are predetermined. The heating control means 206 is controlled via the power supply circuit 1111 so that the temperature of the heating member 203 and the second heater lamp 463d are energized.

  In the fixing device 40 configured to include the first fixing unit 450 and the second fixing unit 460 as described above, the device control unit 111 causes the second fixing unit to compensate for the temperature fluctuation of the first fixing unit 450. The temperature of 460 is controlled (referred to as gloss compensation mode), and control is performed so that the gloss of the image in continuous paper passing (continuous fixing processing) is substantially uniform.

  First, a temperature relational expression between the first fixing belt 454 and the second fixing belt 464 is obtained in advance so that the gloss of the plurality of images to be output is substantially uniform. That is, by controlling the temperature of the second fixing belt 464 so that the temperature of the first fixing belt 454 is equal to the temperature obtained by the above relational expression, the temperature of the first fixing belt 454 is controlled regardless of the temperature of the first fixing roller 452. An image having a certain gloss is obtained.

  For the first fixing unit 450, the apparatus control unit 111 detects the difference between the surface temperature T 1 of the first fixing belt 454 detected by the first fixing roller side thermistor 456 and the target temperature setting value T 2 of the first fixing belt 454. (T1-T2) is obtained as the temperature fluctuation value α of the first fixing belt 454, and when the temperature fluctuation value α exceeds the temperature ripple in the temperature adjustment when the first fixing belt 454 is not passing, the gloss correction temperature adjustment is performed. Control by mode. Assuming that the target set temperature in the state of the second fixing belt 464 is T4, a value obtained by adding the temperature correction value β of the second fixing belt 464 to the target set temperature T4 of the second fixing belt 464 in the gloss correction temperature adjustment mode. The temperature of the second fixing belt 464 is controlled at (T4 + β). For the second fixing unit 460, the apparatus control unit 111 substitutes the surface temperature (T2 + α) of the first fixing belt 454 into the above relational expression to obtain the control temperature (T4 + β) of the second fixing belt 464, and performs temperature control. Do. The gloss correction temperature adjustment mode ends when the continuous fixing process ends or when the temperature fluctuation value α of the first fixing belt 454 becomes equal to or less than a predetermined value, and control in the normal mode is performed.

  FIG. 15 is a diagram illustrating a configuration of a fixing device 50 according to another embodiment of the present invention. The fixing device 50 includes a fixing unit 540 and a pressure unit 550. The fixing device 50 fixes the recording paper 32 carrying the unfixed toner image 31 at a fixing nip formed between the fixing unit 540 and the pressure unit 550. The fixing device 50 can be mounted on the image forming apparatus 100 instead of the fixing device 15. The fixing unit 540 included in the fixing device 50 includes any one of the heating members 20, 30, and 30A of the present embodiment described above. A case where the fixing unit 540 includes the heating member 20 will be described below.

  The fixing unit 540 includes the heating member 20, a fixing roller 542, and a fixing belt 543 that is an endless belt. In the fixing unit 540, the fixing belt 543 is stretched between the fixing roller 542 and the heating member 20.

  As described above, the heating member 20 included in the fixing unit 540 includes the heat radiating member 201, the low-hardness and good heat conducting member 202, and the heat generating region divided into three axial ends and a central portion of the heat radiating member 201. A member 203 and a pressing member 204 are included. Further, a fixed adapter 205 is provided on the extending portion 2040 of the pressing member 204, and the pressing member 204 is fixed to the side frame of the fixing device 50 via the fixed adapter 205. The cylindrical portion 201 a of the heat radiating member 201 is in contact with the fixing belt 543 on the outer peripheral surface, and transfers heat generated by the heat generating member 203 to the fixing belt 543. Further, a heating element side thermistor 545 for detecting the surface temperature of the fixing belt 543 wound around the heating member 20 in a non-contact manner is disposed in the vicinity of the surface of the fixing belt 543.

  The fixing roller 542 is a roller-like member having an outer diameter of 30 mm that conveys the fixing belt 543 by being rotationally driven in the rotation direction X around the rotation axis by the drive motor 113. The fixing roller 542 has a three-layer structure in which a core metal 542a, an elastic layer 542b, and a surface layer 542c are formed in order from the inside. The core metal 542a has, for example, heat conduction such as iron, stainless steel, aluminum, and copper. High performance metals or alloys thereof are used. Examples of the shape of the core metal 542a include a cylindrical shape and a columnar shape, but a cylindrical shape with a small amount of heat radiation from the core metal 542a is preferable. For the elastic layer 542b, a heat-resistant rubber material such as silicon rubber, fluorine rubber, or fluorosilicone rubber is suitable, and among these, silicon rubber that is particularly excellent in rubber elasticity is preferable.

  The material constituting the surface layer 542c is not particularly limited as long as it is excellent in heat resistance and durability and has high slidability. For example, a fluorine resin material such as PFA or PTFE, fluorine rubber, or the like is used. May be. It is also possible to have a two-layer structure without providing a surface layer. Further, a heating unit that heats the fixing roller 542 may be provided inside the fixing roller 542. This is because the start-up time from when the image forming apparatus 100 is turned on until the image can be formed is shortened, and the surface temperature of the fixing roller 542 is lowered due to the transfer of heat to the recording paper 32 when the toner image is fixed. This is to prevent it.

  The fixing belt 543 is heated to a predetermined temperature by the heating member 20 and heats the recording paper 32 on which the unfixed toner image 31 conveyed in contact with the fixing belt 543 is formed. The fixing belt 543 is an endless belt, is suspended by the heating member 20 and the fixing roller 542, and is wound around the fixing roller 542 at a predetermined angle. When the fixing roller 542 rotates, the fixing belt 543 rotates in the rotation direction X following the fixing roller 542. The fixing belt 543 is provided so as to come into contact with the pressure belt 553 at a pressure contact portion between the fixing roller 542 and a pressure roller 552 described later.

  The fixing belt 543 has a three-layer structure including a base material layer, an elastic layer, and a release layer, and is an endless belt having a thickness of 270 μm formed in a cylindrical shape having a diameter of 60 mm. The material constituting the base material layer is not particularly limited as long as it is excellent in heat resistance and durability, and examples thereof include heat-resistant synthetic resins. Among them, polyimide (PI), polyamideimide (PAI) and the like can be mentioned. preferable. These resins are not only high-strength and high-heat-resistant materials, but also are inexpensive. The thickness of the base material layer is not particularly limited, but is preferably 30 to 200 μm. In the present embodiment, the base material layer is made of polyimide and has a thickness of 100 μm.

  The material constituting the elastic layer is not particularly limited as long as it has rubber elasticity, but is preferably superior in heat resistance. Specific examples of such materials include silicon rubber, fluorine rubber, fluorosilicone rubber, and the like. Among these, silicon rubber is particularly preferable because of its excellent rubber elasticity and good heat resistance. The surface hardness of the elastic layer is preferably 1 to 60 degrees in terms of JIS-A hardness. Within this JIS-A hardness range, it is possible to prevent poor toner fixability while preventing a decrease in strength of the elastic layer and poor adhesion. Specific examples of silicon rubber having such characteristics include one-component, two-component or three-component or more silicon rubber, LTV type, RTV type or HTV type silicon rubber, condensation type or addition type silicon rubber. Rubber etc. are mentioned. Moreover, it is preferable that the thickness of an elastic layer is 30-500 micrometers. If it is this thickness range, heat insulation can be restrained low, maintaining the elastic effect of an elastic layer, and the energy saving effect can be exhibited. In the present embodiment, the elastic layer is made of silicon rubber having a JIS-A hardness of 5 degrees and a thickness of 150 μm.

  The release layer is made of a fluororesin tube. Since the release layer formed on the outer peripheral side of the fixing belt 543 is composed of a fluororesin tube, the release layer is formed by applying a resin containing a fluororesin and firing the resin. Excellent durability. In addition, when forming a release layer by coating and baking, a high-precision and expensive mold is required to obtain a release layer with high dimensional accuracy. A mold release layer with high dimensional accuracy can be obtained without using a simple mold. The thickness of the release layer is preferably 5 to 50 μm. Within this thickness range, it is possible to follow the minute irregularities of the recording paper 32 while having an appropriate strength and utilizing the elasticity of the elastic layer. In the present embodiment, a PTFE tube having a thickness of about 20 μm is used as the release layer.

  Next, the pressurizing unit 550 will be described. The pressure unit 550 includes a pressure roller 551, a tension roller 552, and a pressure belt 553 that is an endless belt. In the pressure unit 550, the pressure belt 553 is stretched between the pressure roller 551 and the tension roller 552. The pressure roller 551 and the tension roller 552 are rotatably supported and supported between left and right side plates (not shown) of the fixing device 530, respectively.

  The pressure belt 553 is configured in the same manner as the fixing belt 543 described above, and rotates following the fixing belt 543 that comes into contact therewith.

  The pressure roller 551 is a roller-shaped member having an outer diameter of 30 mm that rotates in the rotation direction Y around the rotation axis along with the rotation of the pressure belt 553 that rotates following the rotation of the fixing belt 543. The pressure roller 551 has a three-layer structure in which a core metal 551a, an elastic layer 551b, and a surface layer 551c are formed in this order from the inside. Examples of the material constituting the metal core 542a, the elastic layer 551b, and the surface layer 551c of the pressure roller 551 include the same materials as the metal core 542a, the elastic layer 542b, and the surface layer 542c of the fixing roller 542 described above. A heating unit 551d for heating the pressure roller 551 is provided inside the pressure roller 551. This is because the start-up time from when the image forming apparatus 100 is turned on until the image can be formed is shortened, and the surface temperature of the pressure roller 551 is abrupt due to the transfer of heat to the recording paper 32 when fixing the toner image. This is to prevent a decrease or the like. In this embodiment, a halogen lamp is used as the heating means 551d.

  The tension roller 552 has an iron alloy cored bar 552a having an outer diameter of 30 mm and an inner diameter of 26 mm, and a silicone sponge layer 552b is provided to reduce the thermal conductivity and reduce the heat conduction from the pressure belt 553. Is provided.

  The fixing device 50 is a so-called twin belt fixing type fixing device in which a fixing nip portion is formed at a portion where the fixing belt 543 and the pressure belt 553 come into contact, and fixing processing is performed at the fixing nip portion. In the fixing device 530, the pressure contact portion where the fixing roller 542 and the pressure roller 552 are in pressure contact with each other via the fixing belt 543 and the pressure belt 553 is the most downstream portion of the fixing nip portion, and the fixing belt 543 and the pressure belt 553. In the entire area of the fixing nip formed at the portion where the contact is made, the most downstream portion is a portion where the pressure distribution in the recording paper conveyance direction is maximized. In this way, by configuring the pressure distribution in the most downstream portion of the fixing nip portion to be maximum, it is possible to prevent the fixing belt 543 and the pressure belt 553 from slipping during rotation.

  The fixing device 50 includes a fixing pad 544 as a first pressure pad that presses the fixing belt 543 toward the pressure belt 553 in order to obtain a wide fixing nip region without increasing the size of the device. A pressure pad 554 serving as a second pressure pad that pressurizes the pressure belt 553 toward the fixing belt 543 is provided. The fixing pad 544 and the pressure pad 554 are supported between the left and right side plates (not shown) of the fixing device 50. The pressure pad 554 is pressed toward the fixing pad 544 with a predetermined pressure in a direction Z close to the fixing pad 544 by a pressing mechanism (not shown). Examples of the material constituting the fixing pad 544 and the pressure pad 554 include PPS (polyphenylene sulfide resin).

  Further, when a fixing nip portion is formed by the fixing pad 544 and the pressure pad 554 that are not rotating bodies, the inner peripheral surfaces of the fixing belt 543 and the pressure belt 553 are rubbed against the pads, and the inner surfaces of the belts 543 and 553 are rubbed. When the friction coefficient between the peripheral surface and each of the pads 544 and 554 is large, the sliding resistance is increased. As a result, problems such as image shift, gear breakage, and increased power consumption of the drive motor 113 occur, and this problem is particularly noticeable in the twin belt system. Therefore, a low friction sheet layer is provided on the contact surfaces of the fixing pad 544 and the pressure pad 554 with the belts 543 and 553. Accordingly, wear of the pads 544 and 554 due to sliding friction with the belts 543 and 553 is prevented and sliding resistance can be reduced, so that good belt running performance and belt durability can be obtained.

  In the present embodiment, the fixing device 50 is configured to heat the fixing belt 543 disposed on the fixing unit 540 side by the heating member 20, but the pressure belt 553 disposed on the pressure unit 550 side is provided. You may comprise so that it may heat with the heating member 20. FIG.

  FIG. 16 is a diagram illustrating a configuration of an image forming apparatus 100 according to an embodiment of the present invention. The image forming apparatus 100 is an apparatus that forms multi-color and single-color images on the recording paper 32 based on image data of a read original or image data transmitted via a network or the like. The image forming apparatus 100 includes any one of the fixing devices 15, 40, and 50 of the present embodiment described above. A case where the image forming apparatus 100 includes the fixing device 15 will be described below.

  The image forming apparatus 100 includes an exposure unit 10, a photosensitive drum 101 (101a to 101d), a developing device 102 (102a to 102d), a charging roller 103 (103a to 103d), a cleaning unit 104 (104a to 104d), and an intermediate transfer belt. 11, a primary transfer roller 13 (13a to 13d), a secondary transfer roller 14, a fixing device 15, paper transport paths P1, P2, and P3, a paper feed cassette 16, a manual paper feed tray 17, and a paper discharge tray 18. .

  The image forming apparatus 100 corresponds to the hues of four colors of cyan (C), magenta (M), and yellow (Y), which are three subtractive primary colors obtained by color separation of black (K) and a color image. Using the image data, image formation is performed in the image forming units Pa to Pd corresponding to each hue. Each of the image forming units Pa to Pd has the same configuration. For example, the black (K) image forming unit Pa includes the photosensitive drum 101a, the developing device 102a, the charging roller 103a, the primary transfer roller 13a, the cleaning unit 104a, and the like. Consists of The image forming portions Pa to Pd are arranged in a line in the moving direction (sub-scanning direction) of the intermediate transfer belt 11.

  The charging roller 103 is a contact-type charger that uniformly charges the surface of the photosensitive drum 101 to a predetermined potential. Instead of the charging roller 103, a contact type charger using a charging brush or a non-contact type charger using a charging wire may be used.

  The exposure unit 10 includes a semiconductor laser (not shown), a polygon mirror 4, a first reflection mirror 7, a second reflection mirror 8, and the like. Black (K), cyan (C), magenta (M), and yellow (Y). Each of the photosensitive drums 101a to 101d is irradiated with a light beam such as a laser beam modulated by the image data of each hue. Each of the photosensitive drums 101a to 101d forms an electrostatic latent image based on image data of each hue of black (K), cyan (C), magenta (M), and yellow (Y).

  The developing device 102 supplies toner as a developer to the surface of the photosensitive drum 101 on which the electrostatic latent image is formed, and develops the electrostatic latent image into a toner image. Each of the developing devices 102a to 102d contains toner of each hue of black (K), cyan (C), magenta (M), and yellow (Y), and is formed on each of the photosensitive drums 101a to 101d. The electrostatic latent image of each hue is visualized into a toner image of each hue. The cleaning unit 104 removes and collects toner remaining on the surface of the photosensitive drum 101 after development and image transfer.

  The intermediate transfer belt 11 is disposed above the photosensitive drum 101, and is stretched between the driving roller 11a and the driven roller 11b to form a loop-shaped moving path. The outer peripheral surface of the intermediate transfer belt 11 faces the photosensitive drum 101d, the photosensitive drum 101c, the photosensitive drum 101b, and the photosensitive drum 101a in this order. Primary transfer rollers 13a to 13d are arranged at positions facing the respective photosensitive drums 101a to 101d with the intermediate transfer belt 11 interposed therebetween. Each of the positions where the intermediate transfer belt 11 faces the photosensitive drums 101a to 101d is a primary transfer position. The intermediate transfer belt 11 is formed of a film having a thickness of about 100 to 150 μm.

  The primary transfer rollers 13a to 13d have constant voltage control of a primary transfer bias opposite to the charging polarity of the toner in order to transfer the toner images carried on the surfaces of the photosensitive drums 101a to 101d onto the intermediate transfer belt 11. Applied. As a result, the toner images of the respective colors formed on the photosensitive drums 101a to 101d are sequentially transferred onto the outer peripheral surface of the intermediate transfer belt 11, and a full-color toner image is formed on the outer peripheral surface of the intermediate transfer belt 11. .

  However, when image data of only a part of the hues of yellow (Y), magenta (M), cyan (C), and black (K) is input, input is performed among the four photosensitive drums 101a to 101d. The electrostatic latent image and the toner image are formed only on a part of the photosensitive drums 101 corresponding to the hue of the image data. For example, when forming a monochrome image, an electrostatic latent image and a toner image are formed only on the photosensitive drum 101a corresponding to the black hue, and only the black toner image is transferred to the outer peripheral surface of the intermediate transfer belt 11. Is done.

  Each of the primary transfer rollers 13a to 13d is configured by covering the surface of a shaft whose base is a metal such as stainless steel having a diameter of 8 to 10 mm with a conductive elastic material (for example, EPDM, urethane foam, etc.). A high voltage is uniformly applied to the intermediate transfer belt 11 by the elastic material.

  The toner image transferred to the outer peripheral surface of the intermediate transfer belt 11 at each primary transfer position is conveyed to a secondary transfer position that is a position facing the secondary transfer roller 14 by the rotation of the intermediate transfer belt 11. The secondary transfer roller 14 is pressed against the outer peripheral surface of the intermediate transfer belt 11 whose inner peripheral surface is in contact with the peripheral surface of the driving roller 11a at a predetermined nip pressure during image formation. When the recording paper 32 fed from the paper feed cassette 16 or the manual paper feed tray 17 passes between the secondary transfer roller 14 and the intermediate transfer belt 11, the secondary transfer roller 14 is charged with the charged polarity of toner. Is applied with a high voltage of reverse polarity. As a result, the toner image is transferred from the outer peripheral surface of the intermediate transfer belt 11 to the surface of the recording paper 32.

  Of the toner adhering to the intermediate transfer belt 11 from the photosensitive drum 101, the toner remaining on the intermediate transfer belt 11 without being transferred onto the recording paper 32 is transferred in order to prevent color mixing in the next process. Collected by the cleaning unit 12.

  The recording paper 32 onto which the toner image has been transferred is guided to the fixing device 15 of the present invention described above, and passes through the fixing nip portion and is heated and pressurized. As a result, the toner image is firmly fixed on the surface of the recording paper 32. The recording paper 32 on which the toner image is fixed is discharged onto the paper discharge tray 18 by the paper discharge roller 18a.

  In the image forming apparatus 100, the recording paper 32 stored in the paper cassette 16 is sent to the paper discharge tray 18 between the secondary transfer roller 14 and the intermediate transfer belt 11 and via the fixing device 15. For this purpose, a sheet conveyance path P1 extending in a substantially vertical direction is provided. A pickup roller 16a that feeds the recording paper 32 in the paper cassette 16 one by one into the paper transport path P1 and a transport roller 16b that transports the fed recording paper 32 upward are transported to the paper transport path P1. A registration roller 19 that guides the recording sheet 32 between the secondary transfer roller 14 and the intermediate transfer belt 11 at a predetermined timing, and a discharge roller 18 a that discharges the recording sheet 32 to the discharge tray 18 are disposed.

  Further, inside the image forming apparatus 100, a paper conveyance path P2 in which a pickup roller 17a and a conveyance roller 16b are arranged is formed between the manual paper feed tray 17 and the registration rollers 19. Further, a paper transport path P3 is formed between the paper discharge roller 18a and the upstream side of the registration roller 19 in the paper transport path P1.

  The paper discharge roller 18a is rotatable in both forward and reverse directions, and is used for the second time in forming a single-sided image for forming an image on one side of the recording paper 32 and in forming a double-sided image for forming images on both sides of the recording paper 32. When the surface image is formed, the recording paper 32 is driven in the forward rotation direction and discharged to the paper discharge tray 18. On the other hand, when the first side image is formed in the double-sided image formation, the paper discharge roller 18a is driven in the normal direction until the rear end of the paper passes through the fixing device 15, and then sandwiches the rear end of the recording paper 32. In this state, the recording paper 32 is driven in the reverse direction to guide the recording paper 32 into the paper transport path P3. Thus, the recording paper 32 on which an image is formed only on one side at the time of double-sided image formation is guided to the paper transport path P1 with the front and back sides and front and rear ends reversed.

  The registration roller 19 receives the recording paper 32 fed from the paper cassette 16 or the manual paper feed tray 17 or transported via the paper transport path P <b> 3 at the timing synchronized with the rotation of the intermediate transfer belt 11. Guided between the transfer roller 14 and the intermediate transfer belt 11. For this reason, the registration roller 19 stops rotating when the operation of the photosensitive drum 101 and the intermediate transfer belt 11 is started, and the recording paper 32 fed or conveyed prior to the rotation of the intermediate transfer belt 11 has a leading edge. The movement in the paper conveyance path P1 is stopped in a state where it is in contact with the registration roller 19. Thereafter, the registration roller 19 is located at a position where the secondary transfer roller 14 and the intermediate transfer belt 11 are pressed against each other, and the front end portion of the recording paper 32 and the front end portion of the toner image formed on the intermediate transfer belt 11 face each other. Start rotation at the timing.

  At the time of full color image formation in which image formation is performed in all of the image forming portions Pa to Pd, the primary transfer rollers 13a to 13d press the intermediate transfer belt 11 against all of the photosensitive drums 101a to 101d. On the other hand, at the time of monochrome image formation in which image formation is performed only in the image forming portion Pa, only the primary transfer roller 13a is brought into pressure contact with the photosensitive drum 101a.

  The image forming apparatus 100 configured as described above includes the fixing device 15 having a uniform fixing characteristic in which the fixing temperature is prevented from being varied with respect to the set temperature, so that a uniform and high-quality image is recorded. It can be formed on paper 32.

(Example)
EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to these Examples.

Example 1
The fixing device used in Example 1 is the fixing device 15 described above. The fixing device 15 was mounted on a copying machine (trade name: MX-4500N, manufactured by Sharp Corporation). Detailed conditions in Example 1 were as follows.

<Fixing roller>
A stainless steel having a diameter of 30 mm, a core metal of 15 mm in diameter, and an elastic layer made of silicon sponge rubber having a thickness of 5 mm was used.

<Pressure roller>
A diameter of 30 mm made of silicon solid rubber, a core metal diameter of 24 mm (thickness 2 mm), a release layer having a 30 μm thick PFA tube, and a heater lamp with a rated power of 400 W inside was used.

<Fixing belt>
A belt in which a polyimide having a thickness of 70 μm was formed on a belt substrate, a silicon rubber having a thickness of 150 μm was formed on an elastic layer, and a PTFE coat having a thickness of 30 μm was formed on a release layer was used.

<Color to prevent meandering>
A polyphenylene sulfide (PPS) collar having an inner diameter of 20 mm, a diameter of 32 mm, and a width of 7 mm was disposed at the end of the fixing roller so as to contact the end of the fixing belt.

<Heating member>
The heating member used in Example 1 is the heating member 30 described above.

[Heat dissipation member]
A mixed material of PTFE and PFA was coated on the outer peripheral surface of a cylindrical body made of aluminum having an axial length of 320 mm and a thickness of 0.5 mm to form an outer surface coating layer having a thickness of 15 μm. Next, a material made of silicone resin (trade name: B-600, manufactured by Okitsumo Co., Ltd.) is spray-applied to the inner peripheral surface of the cylindrical body, and then baked at 180 ° C. for 20 minutes to form an inner surface coat having a thickness of 35 μm A layer was formed. In this way, a part of the cylindrical body in which the outer surface coating layer and the inner surface coating layer are formed is cut out in the circumferential direction, the curvature radius R1 is 15 mm (diameter 30 mm), and the elevation angle θ with respect to the axial line at both ends in the circumferential direction is Cylindrical part A which becomes 216 ° (narrow angle is 144 °) was produced.

[Pressing member]
A cylindrical body made of stainless steel having an axial length of 357 mm and a wall thickness of 0.2 mm is cut away, and a radius of curvature R2 is 15.5 mm (diameter 31 mm). A pressing member A having an elevation angle with respect to the axis of 216 ° (a narrow angle of 144 °) was produced. At this time, corresponding to the length of the pressing member in the axial direction, the region portion that is longer outward than the axial length of the heat radiating member becomes an extending portion, and the extending portion extends at each axial end. The length is the same. Note that the pressing member A does not have an opening that penetrates and opens in the thickness direction, and is a solid plate member.

[Heat generation member]
The heat generating member used in Example 1 is the heat generating member 203 described above. Nickel chromium foil pattern etching heating element (thickness 80 μm, width 0.90 mm to 1.06 mm, volume resistivity 107.3 × 10 ⁻⁸ Ωcm) A mica sheet having a thickness of 0.1 mm was laminated to form a second insulating layer and a third insulating layer. At this time, the interval P1 between adjacent linear portions in the resistance heating element is 1.2 mm. Next, a polyimide sheet having a thickness of 25 μm made of polyimide (trade name: Kapton (registered trademark), manufactured by DuPont) is laminated on the surfaces of the second and third insulating layers, and the first insulating layer and the fourth insulating layer are laminated. A layer was formed to produce a heat generating member A.

[Low hardness, good thermal conductive material]
The material constituting the low-hardness heat-conductive member A is a silicone-based grease heat-dissipating agent A, a heat-dissipating silicon SCH-30 manufactured by Sanhayato Co., Ltd. (heat resistance 300 ° C., heat conductivity 2 × 10 ⁻³ cal / s • cm · ° C. (0.84 W / m · K), hardness at 25 ° C. 300) was used.

[Preparation of heating member A]
A silicone-based grease heat-dissipating agent A was applied to the inner peripheral surface of the cylindrical portion A produced as described above, and a low-hardness heat-conductive member A having a thickness of about 50 μm was formed. Next, the heat generating member A is disposed so that the first insulating layer is in contact with the surface of the low hardness and good heat conducting member A, and the pressing member A is disposed so as to be in contact with the surface of the fourth insulating layer of the heat generating member A. did. And the both ends of the circumferential direction of the cylindrical part A were bend | folded inside, and the some bending piece was formed, and it was set as the heat radiating member A. At this time, one bent piece has a rectangular shape (10 mm × 7 mm), and eight bent pieces are formed at each circumferential end of the cylindrical portion A with an interval of 40 mm in the axial direction. did. And the fixing adapter was attached to the extension part of the press member A, and the heating member A of Example 1 was produced. The heating member A of Example 1 had an insulation resistance of 100 MΩ or more and a withstand voltage of AC 1500 V / 1 minute. The heating member A was fixed to the side frame of the copying machine via a fixed adapter.

<Thermistor>
One non-contact infrared sensor as the heating element side thermistor is installed at the center and one end of the fixing belt in the width direction so that the contact thermistor contacts the pressure roller surface as the pressure roller side thermistor. Installed.

<Device control means>
The apparatus control means controls the power supply to the heat generating area divided into three parts based on the temperature detected by the heat generating body side thermistor. Further, the apparatus control means controls the power supply to the heater lamp of the pressure roller based on the temperature detected by the pressure roller side thermistor when the paper is passed.

<Safety device>
A thermal protector is arranged in the vicinity of the outer peripheral surface of the fixing belt, and the power supply circuit is disconnected when the surface temperature of the fixing belt becomes abnormally high.

<Fixing conditions>
Fixing nip length: 8.5 mm (length of the fixing nip in the recording paper conveyance direction)
Fixing speed: 220mm / sec
Heating nip length: 44 mm (contact length in the recording paper conveyance direction between the fixing belt and the heating member)
Heating nip width: 330 mm (length corresponding to the axial direction of the fixing roller)

<Operation of copier>
First, a 100 V power supply and device control means were connected to the heating member A of the heating member A produced as described above, and the electrical resistance value at 20 ° C. of the heating member A was measured. 33Ω, the central region was 12.32Ω, and each end region was 12.95Ω. Next, the warm-up time in the copying machine, the temperature variation when 50 sheets were continuously fed, and the edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heat generating member A, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is as follows: 21.0 sec. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  The distribution of power supplied to the heat generating member A is controlled by setting the heat generation area at the central portion in the axial direction to 812 W at 100 V and the heat generation area at both ends in the axial direction to 193 W at 50 V, distinguishing between the energization at the central portion and both ends. As a result, there was almost no unevenness in image density during continuous paper feeding, and a high-quality image was obtained. Further, through the energization time control and the phase control for the central portion and both ends of the heat generating member A in the axial direction, the heat generation temperature distribution in the axial direction of the heat generating member A is increased in the central portion, so that small size paper is passed. When the temperature at both ends in the axial direction of the heating member A was measured with a heating element side thermistor, no excessive temperature rise was observed, and an increase in power consumption could be efficiently suppressed.

  Further, since the outer surface coating layer is formed on the outer peripheral surface of the heat radiating member A that contacts the fixing belt, the heating member A is suppressed from increasing the frictional force between the heat radiating member A and the fixing belt. The belt sliding was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

  Further, the temperature distribution on the surface of the heating member A did not vary with respect to the set temperature even during continuous paper feeding, and the heat transfer efficiency with respect to the fixing belt did not decrease. Furthermore, even after printing 200K sheets, local peeling did not occur between the members constituting the heating member A, there was no problem in safety, and the warm-up time and resistance value were the same as in the initial stage. .

  Therefore, it has been possible to provide a copying machine provided with an energy-saving fixing device as well as ensuring reliability and safety over a long period of time and maintaining the life of the heating member A.

(Example 2)
The fixing device used in Example 2 is the fixing device 15 described above. And it carried out similarly to Example 1 except having performed the heating member as follows.

<Heating member>
The heating of Example 1 except that the heat generating member B was prepared as a heat generating element (thickness 50 μm, pattern width 0.22 mm to 0.33 mm) using a stainless steel (SUS304H) foil as the resistance heating element constituting the heat generating layer. The heating member B of Example 2 was produced in the same manner as the member A.

<Operation of copier>
First, a 100 V power supply and device control means were connected to the heating member B of the heating member B produced as described above, and the electrical resistance value at 20 ° C. of the heating member B was measured. The electrical resistance value in the central region was 12.12Ω, and the electrical resistance value in each end region was 13.37Ω. Next, the warm-up time in the copying machine, the temperature variation when 50 sheets were continuously fed, and the edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heating member B, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 21.7 sec, and the target warm is 30 sec or less. The up time could be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member B when small-size paper was passed was measured with a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  Further, since the heating member B is formed with the outer surface coating layer in the same manner as the heating member A of Example 1, an increase in the frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

  Further, the temperature distribution on the surface of the heating member B did not vary with respect to the set temperature even during continuous paper feeding, and the heat transfer efficiency with respect to the fixing belt did not decrease. Further, even after printing 200K sheets, local peeling did not occur between the members constituting the heating member B, there was no problem in safety, and the warm-up time and the resistance value were the same as in the initial stage. .

  Therefore, it has been possible to provide a copying machine equipped with an energy-saving fixing device as well as ensuring reliability and safety over a long period of time and maintaining the life of the heating member B.

(Example 3)
The fixing device used in Example 3 is the fixing device 15 described above. And it carried out similarly to Example 1 except having performed the heating member as follows.

<Heating member>
As a material constituting the low-heat hardness and heat-conducting member, a sheet-like heat conducting gel λ _GEL COH-4000 manufactured by Taika Co., Ltd., which is a silicone-based gel sheet heat dissipating material (heat resistance 250 ° C., heat conductivity 6.5 W / m · A heating member C of Example 3 was manufactured in the same manner as the heating member A of Example 1 except that the low hardness and good heat conductive member C was prepared using K, hardness 50) at 25 ° C.

<Operation of copier>
The warm-up time in the copying machine, temperature variation when 50 sheets were continuously passed, and edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 22.0 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member C when small-size paper was passed was measured with a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  Further, since the heating member C is formed with the outer surface coating layer similarly to the heating member A of Example 1, an increase in the frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

  Further, the temperature distribution on the surface of the heating member C did not vary with respect to the set temperature even during continuous paper feeding, and the heat transfer efficiency with respect to the fixing belt did not decrease. Further, even after printing 200K sheets, local peeling did not occur between the members constituting the heating member C, there was no problem in safety, and the warm-up time and resistance value were the same as in the initial stage. .

  Therefore, it is possible to provide a copying machine equipped with an energy-saving fixing device as well as ensuring reliability and safety over a long period of time and maintaining the life of the heating member C.

Example 4
The fixing device used in Example 4 is the fixing device 15 described above. And it carried out similarly to Example 1 except having performed the heating member as follows.

<Heating member>
The second insulating layer and the third insulating layer were formed by laminating mica sheets made of mica having a thickness of 0.1 mm on both surfaces of the heat generating layer made of the resistance heating element similar to the heat generating member A of Example 1. Next, a first insulating layer is formed by laminating a polyimide sheet having a thickness of 25 μm made of polyimide (trade name: Kapton (registered trademark), manufactured by DuPont) on the surface of the second insulating layer. A fourth insulating layer was formed by laminating a polyimide sheet having a thickness of 1.0 mm and a circumferential length of 56.5 mm on the surface, and a heating member D was produced. And the heating member of Example 4 was comprised so that the 4th insulating layer of the heat generating member D produced as mentioned above might serve as a press member. At this time, the fourth insulating layer that also serves as the pressing member has a curvature radius R2 of 15.5 mm and an elevation angle of 216 ° with respect to the axial lines at both ends in the circumferential direction. Except this, it carried out similarly to Example 1, and produced the heating member D of Example 4. FIG.

<Operation of copier>
The warm-up time in the copying machine, temperature variation when 50 sheets were continuously passed, and edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 21.5 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member D when passing small-size paper was measured with a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  Further, since the heating member D has an outer surface coating layer formed similarly to the heating member A of Example 1, an increase in frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

  Further, the temperature distribution on the surface of the heating member D did not vary with respect to the set temperature even during continuous paper feeding, and the heat transfer efficiency with respect to the fixing belt did not decrease. Furthermore, even after printing 200K sheets, local peeling did not occur between the members constituting the heating member D, there was no problem in safety, and the warm-up time and resistance value were the same as in the initial stage. .

  Therefore, it is possible to provide a copying machine equipped with an energy-saving fixing device as well as ensuring reliability and safety over a long period of time and maintaining the life of the heating member C.

(Example 5)
The fixing device used in Example 5 is the fixing device 15 described above. And it carried out similarly to Example 1 except having performed the heating member as follows.

<Heating member>
Using a zirconia thin plate (Ceraflex-A, manufactured by Nippon Fine Ceramics Co., Ltd.), which is a bending ceramic that does not break even when bent, as the material constituting the pressing member, the thickness is 0.5 mm and the length in the circumferential direction A pressing member E having a length of 56.5 mm was produced. At this time, the pressing member E has a curvature radius R2 of 15.5 mm and an elevation angle with respect to the axis at both ends in the circumferential direction is 216 °. Except this, it carried out similarly to Example 1, and produced the heating member E of Example 5. FIG.

<Operation of copier>
The warm-up time in the copying machine, temperature variation when 50 sheets were continuously passed, and edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 21.0 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member E when small-size paper was passed was measured with a heating element side thermistor, no excessive temperature rise was observed, and an increase in power consumption could be efficiently suppressed.

  Further, since the heating member E is formed with the outer surface coating layer similarly to the heating member A of Example 1, an increase in the frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

  Further, the temperature distribution on the surface of the heating member E did not vary with respect to the set temperature even during continuous paper feeding, and the heat transfer efficiency with respect to the fixing belt did not decrease. Further, even after printing 200K sheets, local peeling did not occur between the members constituting the heating member E, there was no problem in safety, and the warm-up time and the resistance value were the same as in the initial stage. .

  Therefore, it is possible to provide a copying machine equipped with an energy-saving fixing device as well as ensuring reliability and safety over a long period of time and maintaining the life of the heating member E.

(Example 6)
The fixing device used in Example 6 is the fixing device 15 described above. And it was made to be the same as that of Example 1 except having performed the press member of the heating member as follows.

[Pressing member]
A cylindrical body made of stainless steel having an axial length of 357 mm and a wall thickness of 0.2 mm is cut away, and a radius of curvature R2 is 14.0 mm (diameter 28 mm). A pressing member F having an elevation angle with respect to the axis of 216 ° (a narrow angle of 144 °) was produced. At this time, corresponding to the length of the pressing member in the axial direction, the region portion that is longer outward than the axial length of the heat radiating member becomes an extending portion, and the extending portion extends at each axial end. The length is the same. Note that the pressing member F does not have an opening that penetrates and opens in the thickness direction, and is a solid plate member.

<Operation of copier>
First, a 100V power source and device control means were connected to the heating member of the heating member produced as described above, and the electrical resistance value at 20 ° C. of the heating member was measured. The overall electrical resistance value was 8.33Ω. The central region was 12.32Ω, and each end region was 12.95Ω. Next, the warm-up time in the copying machine, the temperature variation when 50 sheets were continuously fed, and the edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heat generating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 25 at both the widthwise center and both ends of the fixing belt. 0.0 sec. The target was 30 seconds or less, but the warm-up time was slightly longer. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

(Example 7)
The fixing device used in Example 7 is the fixing device 15 described above. And it carried out similarly to Example 2 except having performed the heating member as follows.

<Heating member>
Similarly to the heat generating member B of Example 2, the heat generating member was manufactured by using a resistance heat generating element constituting the heat generating layer as a heat generating element (thickness 50 μm, pattern width 0.22 mm to 0.33 mm) using stainless steel (SUS304H) foil. did. And the heating member G of Example 7 was produced like the heating member B of Example 2 except having made the pressing member G into the pressing member shown below. The pressing member G has a length of 357 mm in the axial direction, a thickness of 0.2 mm, and a plurality of openings regularly arranged so that the minimum width dimension of the peripheral edge of the opening is 1.0 mm. A portion corresponding to the circumferential end of the stainless steel plate is cut out, the curvature radius R2 is 15.5 mm (diameter 31 mm), and the elevation angle with respect to the axis at both circumferential ends is 216 ° (the narrow angle is 144 °). It was produced by bending.

<Operation of copier>
First, a 100V power source and device control means were connected to the heat generating member of the heating member G manufactured as described above, and the electric resistance value at 20 ° C. of the heat generating member was measured. The overall electric resistance value was 8.34Ω. Yes, the electrical resistance value in the central region was 12.12Ω, and the electrical resistance value in each end region was 13.37Ω. Next, the warm-up time in the copying machine, the temperature variation when 50 sheets were continuously fed, and the edge temperature rise when small-size sheets were passed were measured.

  When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 20.8 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member when small-size paper was passed was measured by a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  In addition, since the heating member G is formed with the outer surface coating layer similarly to the heating member B of Example 2, an increase in the frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

  Further, the temperature distribution on the surface of the heating member G did not vary with respect to the set temperature even during continuous paper feeding, and the heat transfer efficiency with respect to the fixing belt did not decrease. Furthermore, even after printing 200K sheets, no local peeling occurred between the members constituting the heating member G, there was no problem in safety, and the warm-up time and resistance value were the same as in the initial stage. .

  Therefore, it has been possible to provide a copying machine equipped with an energy-saving fixing device as well as ensuring reliability and safety over a long period of time and maintaining the life of the heating member.

(Example 8)
The fixing device used in Example 8 is the fixing device 15 described above. And it carried out similarly to Example 7 except having performed the heating member as follows.

<Heating member>
[Heat dissipation member]
An axial length of 320 mm and a cylindrical body made of aluminum having a thickness of 0.5 mm (outer surface coating layer and inner surface coating layer are formed) are cut out in a circumferential direction so that the radius of curvature R1 is A heat radiating member H having a diameter of 15 mm (diameter: 30 mm) and an elevation angle θ with respect to the axial lines at both ends in the circumferential direction being 180 ° (a narrow angle being 180 °) was produced. In addition, the heat radiating member H is formed with a bent piece, similarly to the heat radiating member of the seventh embodiment.

[Pressing member]
The circumference of the stainless steel plate in which the length in the axial direction is 357 mm, the wall thickness is 0.2 mm, and the plurality of openings are regularly arranged at intervals so that the minimum width dimension of the opening periphery is 1.0 mm. The portion corresponding to the end in the direction is cut out and bent so that the curvature radius R2 is 15.5 mm (diameter 31 mm) and the elevation angle with respect to the axis at both ends in the circumferential direction is 180 ° (the narrow angle is 180 °). H was produced.

[Heat generation member]
Similarly to the heat generating member of Example 7, the heat generating member H is manufactured by using a resistance heat generating element constituting the heat generating layer as a heat generating element (thickness 50 μm, pattern width 0.22 mm to 0.33 mm) using stainless steel (SUS304H) foil. did.

  A heating member H of Example 8 was produced in the same manner as the heating member G of Example 7, except that the heat radiating member H, the pressing member H, and the heat generating member H were used.

<Operation of copier>
When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 19.3 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member when small-size paper was passed was measured by a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  In addition, since the heating member H is formed with the outer surface coating layer in the same manner as the heating member G of Example 7, an increase in frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

Example 9
The fixing device used in Example 9 is the fixing device 15 described above. And it carried out similarly to Example 7 except having performed the heating member as follows.

<Heating member>
[Heat dissipation member]
An axial length of 320 mm and a cylindrical body made of aluminum having a thickness of 0.5 mm (the outer surface coating layer and the inner surface coating layer are formed) are cut out in a circumferential direction so that the radius of curvature R1 is A heat radiating member I having a height of 15 ° (diameter 30 mm) and an elevation angle θ of 320 ° (narrow angle of 40 °) with respect to the axial lines at both ends in the circumferential direction was produced. In addition, the heat radiating member I is formed with a bent piece, similarly to the heat radiating member of the seventh embodiment.

[Pressing member]
The circumference of the stainless steel plate in which the length in the axial direction is 357 mm, the wall thickness is 0.2 mm, and the plurality of openings are regularly arranged at intervals so that the minimum width dimension of the opening periphery is 1.0 mm. The portion corresponding to the end of the direction is cut out and bent so that the radius of curvature R2 is 15.5 mm (diameter 31 mm) and the elevation angle with respect to the axis at both ends in the circumferential direction is 320 ° (narrow angle is 40 °). I was produced.

[Heat generation member]
Similarly to the heat generating member of Example 7, the heat generating member I was prepared by using a resistance heat generating element constituting the heat generating layer as a heat generating element (thickness 50 μm, pattern width 0.22 mm to 0.33 mm) using stainless steel (SUS304H) foil. did.

  A heating member I of Example 9 was produced in the same manner as the heating member G of Example 7 except that the heat radiating member I, the pressing member I, and the heat generating member I were used.

<Operation of copier>
When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 29.9 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member when small-size paper was passed was measured by a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  In addition, since the heating member I is formed with the outer surface coating layer similarly to the heating member G of Example 7, an increase in the frictional force between the heat dissipation member and the fixing belt is suppressed, and the fixing belt slides. The movement was smooth with no frictional resistance, and there was no meandering of the fixing belt. Furthermore, since a non-contact thermistor was used for temperature detection on the surface of the fixing belt, the surface of the fixing belt was not damaged, and a belt life of 200K sheets could be secured.

(Example 10)
The fixing device used in Example 10 is the fixing device 15 described above. And it carried out similarly to Example 7 except having performed the heating member as follows.

<Heating member>
[Heat dissipation member]
An axial length of 320 mm and a cylindrical body made of aluminum having a thickness of 0.5 mm (the outer surface coating layer and the inner surface coating layer are formed) are cut out in a circumferential direction so that the radius of curvature R1 is A heat dissipating member J having an elevation angle θ of 15 mm (diameter 30 mm) with respect to the axial lines at both ends in the circumferential direction of 179 ° was produced. In addition, the heat radiating member J is formed with a bent piece similarly to the heat radiating member of the seventh embodiment.

[Pressing member]
The circumference of the stainless steel plate in which the length in the axial direction is 357 mm, the wall thickness is 0.2 mm, and the plurality of openings are regularly arranged at intervals so that the minimum width dimension of the opening periphery is 1.0 mm. A pressing member J was manufactured by cutting out a portion corresponding to the end portion in the direction and bending the radius of curvature R2 to 15.5 mm (diameter 31 mm) and the elevation angle with respect to the axis at both ends in the circumferential direction to be 179 °.

[Heat generation member]
Similarly to the heat generating member of Example 7, the heat generating member J was prepared by using a resistance heat generating element constituting the heat generating layer as a heat generating element (thickness 50 μm, pattern width 0.22 mm to 0.33 mm) using stainless steel (SUS304H) foil. did.

  A heating member J of Example 10 was produced in the same manner as the heating member G of Example 7, except that the heat radiating member J, the pressing member J, and the heat generating member J were used.

<Operation of copier>
When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 20.1 sec, and the target warm-up is 30 sec or less. Time was able to be achieved stably. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  Further, there was almost no image density unevenness in continuous paper passing, and a high quality image was obtained. Furthermore, when the temperature at both ends in the axial direction of the heating member when small-size paper was passed was measured by a heating element side thermistor, no excessive temperature increase was observed, and an increase in power consumption could be efficiently suppressed.

  Further, since the heating member J is formed with the outer surface coating layer in the same manner as the heating member G of Example 7, an increase in the frictional force between the heat dissipation member and the fixing belt is suppressed. However, in the fixing belt, since friction was large in a region in contact with the edge portion of the bent piece of the heat radiating member J, the belt was observed to be biased, but 200K prints could be secured.

(Example 11)
The fixing device used in Example 11 is the fixing device 15 described above. And it carried out similarly to Example 7 except having performed the heating member as follows.

<Heating member>
[Heat dissipation member]
An axial length of 320 mm and a cylindrical body made of aluminum having a thickness of 0.5 mm (the outer surface coating layer and the inner surface coating layer are formed) are cut out in a circumferential direction so that the radius of curvature R1 is A heat dissipating member K having a diameter of 15 mm (diameter: 30 mm) and an elevation angle θ of 321 ° (narrow angle of 39 °) with respect to the axis at both ends in the circumferential direction was produced. In addition, the heat radiating member K is formed with a bent piece, similarly to the heat radiating member of the seventh embodiment.

[Pressing member]
The circumference of the stainless steel plate in which the length in the axial direction is 357 mm, the wall thickness is 0.2 mm, and the plurality of openings are regularly arranged at intervals so that the minimum width dimension of the opening periphery is 1.0 mm. A portion corresponding to the end portion in the direction is cut out and bent so that the curvature radius R2 is 15.5 mm (diameter 31 mm) and the elevation angle with respect to the axis at both ends in the circumferential direction is 321 ° (narrow angle is 39 °). K was produced.

[Heat generation member]
Similarly to the heat generating member of Example 7, the heat generating member K is manufactured by using a resistance heat generating element constituting the heat generating layer as a heat generating element (thickness 50 μm, pattern width 0.22 mm to 0.33 mm) using stainless steel (SUS304H) foil. did.

  A heating member K of Example 11 was produced in the same manner as the heating member G of Example 7 except that the heat radiating member K, the pressing member K, and the heat generating member K were used.

<Operation of copier>
When a voltage of 100 V is applied to the entire heating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 29.8 sec, and the target of 30 sec or less can be achieved. It was. There was no problem with the fixability of the fixed image on the recording paper immediately after the warm-up was completed.

  In addition, since the heating member K is formed with the outer surface coating layer similarly to the heating member G of Example 7, an increase in frictional force between the heat dissipation member and the fixing belt is suppressed, and the circumferential end portion is reduced. There was no edge, the sliding of the fixing belt was smooth with no frictional resistance, and there was no meandering of the fixing belt. However, since the narrow angle of the heat radiating member is small, it takes time to produce the heating member.

(Comparative Example 1)
The heating member was the same as Example 1 except that it was as follows. In addition, the heating member in the comparative example 1 does not have a bent piece on the heat radiating member, and does not have a low hardness and good heat conducting member.

<Heating member>
[Heat dissipation member]
A cylindrical body made of aluminum having an axial length of 320 mm and a wall thickness of 0.5 mm is cut away, and a radius of curvature R1 is 15 mm (diameter 30 mm). A cylindrical heat radiating member L having an elevation angle θ of 216 ° was produced.

[Pressing member]
A spiral spring member having a wire diameter of 0.5 mm for each strip was prepared as the pressing member L in Comparative Example 1.

[Heat generation member]
A stainless steel (NCA1BA) foil pattern etching heating element (thickness 50 μm, pattern width 0.18 to 0.27 mm) is laminated on both surfaces of a heating layer made of a resistance heating element by laminating a polyimide sheet with a thickness of 25 μm. The heat generating member L was formed.

[Preparation of heating member H]
An epoxy adhesive having high heat resistance was applied to the inner peripheral surface of the heat dissipating member L produced as described above, and the heat generating member L was pasted thereon. And it fixed so that the outer peripheral part of the radial direction outer side of each strip | belt of the helical pressing member L might contact the surface of the heat generating member L, and the heating member L of the comparative example 1 was produced.

<Operation of copier>
First, a 100 V power source and device control means were connected to the heating member H of the heating member L produced as described above, and the electrical resistance value at 20 ° C. of the heating member L was measured. The electric resistance value in the central region was 12.32Ω, and the electric resistance values in the end regions were 12.95Ω, respectively.

  When a voltage of 100 V was applied to the entire heating member L, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) was 20.3 sec.

  However, when several tens of sheets were printed, abnormal overheating occurred and the polyimide smelled. When the heating member L was visually observed, a part of the heat generating member L was peeled off from the heat radiating member L, and the polyimide of the insulating layer was carbonized and discolored.

Further, in Comparative Example 1, image density unevenness was caused by continuous paper passing, resulting in an image defect. Furthermore, when the temperature at both ends in the axial direction of the heating member L when the small size paper was passed was measured with a heating element side thermistor, an excessive temperature increase occurred and the heating member L and the fixing belt were damaged.
(Comparative Example 2)
The heating member was the same as Comparative Example 1 except that it was as follows. In addition, although the bending piece is not formed in the heat radiating member, the heating member in the comparative example 2 has a low-hardness good heat conductive member.

<Heating member>
[Heat dissipation member]
A cylindrical body made of aluminum having an axial length of 320 mm and a wall thickness of 0.5 mm is cut away, and a radius of curvature R1 is 15 mm (diameter 30 mm). A cylindrical heat radiating member M having an elevation angle θ of 216 ° was produced.

[Pressing member]
A spiral spring member having a wire diameter of 0.5 mm was prepared as the pressing member M in Comparative Example 2.

[Heat generation member]
A stainless steel foil pattern etching heating element (thickness 50 μm, pattern width 0.18 to 0.27 mm) is formed on both surfaces of a heating layer made of a resistance heating element by laminating a polyimide sheet with a thickness of 25 μm to form an insulating layer, A heat generating member M was produced.

[Production of heating member]
As a material constituting the low hardness and good heat conducting member A used in Example 1 on the inner peripheral surface of the heat dissipating member M produced as described above, the heat dissipated by Sanhayato Co., Ltd., which is a silicone-based grease heat dissipating agent A. The conductive silicon SCH-30 was applied, and a heat generating member was attached thereon. And it fixed so that the outer peripheral part of the radial direction outer side of each strip | belt of a helical pressing member might contact the surface of the heat generating member M, and the heating member M of the comparative example 2 was produced.

<Operation of copier>
First, a 100 V power supply and device control means were connected to the heating member M of the heating member M produced as described above, and the electrical resistance value at 20 ° C. of the heating member M was measured. The electric resistance value in the central region was 12.32Ω, and the electric resistance values in the end regions were 12.95Ω, respectively.

  When a voltage of 100 V was applied to the entire heat generating member M, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) was 20.5 sec.

  However, when several sheets were printed, abnormal overheating occurred and the polyimide smelled. When the heating member M was visually observed, a part of the heat generating member M was peeled off from the heat radiating member M, and the polyimide of the insulating layer was carbonized and discolored. In Comparative Example 2, continuous paper could not be passed, and no further evaluation was possible.

(Comparative Example 3)
Example 1 except that the heat-radiating silicon SCH-30 manufactured by Sunhayato Co., Ltd., which is a silicone-based grease heat-dissipating agent A, was not used as the material constituting the low-altitude good heat-conducting member A configured as the heating member The same was done. In other words, the heating member N in Comparative Example 3 has a bent piece formed on the heat radiating member, but does not have a low hardness and good heat conducting member.

<Operation of copier>
First, a 100V power supply and device control means were connected to the heating member N of the heating member N produced as described above, and the electrical resistance value at 20 ° C. of the heating member was measured. The overall electrical resistance value was 8.33Ω. Yes, the electric resistance value in the central region was 12.32Ω, and the electric resistance values in the end regions were 12.95Ω, respectively.

  When a voltage of 100 V is applied to the entire heat generating member, the time required for the entire fixing belt surface temperature on the fixing roller to reach 180 ° C. (warm-up time) is 30.2 sec, and the target is 30 seconds or less. There wasn't. Further, in Comparative Example 3, image density unevenness was caused by continuous paper passing, resulting in an image defect.

15, 40, 50 Fixing device 15a Fixing roller 15b Pressure roller 20, 30, 30A Heating member 25 Fixing belt 100 Image forming device 201, 301, 302 Heat radiation member 201a, 301a, 302a Tubular portion 201b, 301b, 302b Bending piece 202 Heat-resistant member with low hardness 203, 303, 403 Heating member 204, 204a, 204b, 204c Pressing member 205 Fixed adapter 20111, 3011, 3021 First bent portion 2012, 3012 Second bent portion 2033, 3033, 4033 Heat generating layer 2040 Extension part 3013 Inner surface coating layer 3014 Outer surface coating layer

Claims (12)

A heat dissipating member having a cylindrical part formed in a cylindrical shape forming a part of a cylindrical body, and a bent piece bent inward from at least a part of both circumferential ends of the cylindrical part;
A material having low hardness and high thermal conductivity, and a low hardness and good thermal conductive member provided in contact with the inner peripheral surface of the heat radiating member;
It has a heat generating layer made of a resistance heating element that generates heat when energized and an insulating layer made of an insulator, and the insulating layer is laminated so as to sandwich the heat generating layer, and is formed on the inner peripheral surface of the low-hardness heat-conductive member. A heat generating member provided in contact;
The heat generating member is formed in a cylindrical shape forming a part of a cylindrical body, contacts the inner peripheral surface of the heat generating member on the outer peripheral surface, and elastically presses the heat generating member in a direction close to the heat radiating member. And a pressing member that holds the member,
The bent piece of the heat radiating member is formed by bending from at least a part of both ends in the circumferential direction of the cylindrical portion in a direction approaching the pressing member, and in a direction approaching the heat generating member with respect to the pressing member A heating member having a bent portion that applies a pressing force to the head.   2. The heating member according to claim 1, wherein a plurality of the bent pieces of the heat radiating member are provided at intervals in an axial direction of the cylindrical portion.   The pressing member is disposed inside the cylindrical portion by deforming a member having a radius of curvature R2 in the circumferential direction larger than the radius of curvature R1 in the circumferential direction of the cylindrical portion of the heat dissipation member. The heating member according to claim 1 or 2, characterized by the above. The heat dissipation member is formed using an alloy selected from an aluminum alloy, a magnesium alloy, and a copper alloy,
The heating member according to any one of claims 1 to 3, wherein the pressing member is formed to have elasticity using a material selected from a metal, a heat-resistant resin, and ceramics. The resistance heating element constituting the heat generating layer of the heat generating member extends in a circumferential direction of the heat radiating member, and a plurality of linear portions formed on the surface of the insulating layer and an extension of the adjacent linear portions. The connecting direction end portions are connected to each other so as to extend in the axial direction of the heat radiating member so as to form a single line, and are formed on the surface of the insulating layer.
The pressing member is configured such that a plurality of openings that penetrate through and open in the thickness direction are regularly arranged at intervals.
The minimum width dimension of the opening peripheral edge part that defines each of the plurality of openings in the pressing member is greater than or equal to the line width of the linear part and the connection part of the resistance heating element. The heating member according to any one of 1 to 4. The pressing member is formed such that its axial length is larger than the axial length of the heat radiating member and the heat generating member, and extends outward from both axial ends of the heat radiating member. Have an extension,
The heating member according to claim 1, wherein the extension portion is provided with a fixing adapter configured to be connected to the outside so as to fix the pressing member.   The heating member according to any one of claims 1 to 6, wherein an elevation angle with respect to the axial lines at both ends in the circumferential direction of the cylindrical portion of the heat dissipation member is selected from 180 ° to 320 °. .   8. The heat radiating member is characterized in that an inner surface coating layer made of a material having heat resistance and high heat radiation is formed on an inner peripheral surface in contact with the low-hardness and high-heat conducting member. The heating member according to any one of the above.   The heating member according to any one of claims 1 to 8, wherein an outer surface coating layer made of a material having heat resistance and a low friction coefficient is formed on an outer peripheral surface of the heat dissipation member.   The heating member according to claim 9, wherein the outer surface coating layer is made of at least one of a PTFE resin and a PFA resin containing fluorine. A rotatable endless belt stretched between a first fixing member and a heating member, and a second fixing member disposed so as to face the first fixing member via the endless belt. A fixing device that heats and fixes a toner image carried on a recording medium on a recording medium at a fixing nip formed by contact between the endless belt and the second fixing member,
The said heating member is a heating member as described in any one of Claims 1-10, It contacts with the said endless belt in the outer peripheral surface of the said heat radiating member, The said endless belt is heated, It is characterized by the above-mentioned. Fixing device to do.   An image forming apparatus comprising the fixing device according to claim 11.

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