JP5383386B2 - Heat fixing device - Google Patents

Description

  The present invention relates to a heat fixing device using a carbon-based resistance heating element such as a graphite heater.

Conventionally, as a heat fixing device, a fixing roller type using a heat roller provided with a heater inside has been widely used. However, this fixing roller type heat fixing device has a problem in terms of energy saving because it is necessary to heat a fixing roller having a large heat capacity, and has a problem that it takes time to start up.
From the above viewpoint, in order to realize a quick start of the apparatus, a heat fixing device using a halogen heater as a heat source has been proposed and put into practical use. There were problems such as a large inrush current at start-up and complicated power supply design of the device.
Based on the above situation, in image forming apparatuses such as copiers and printers, as a heat source of a heat fixing device that fixes toner onto a recording material such as paper by heating, it has been conventionally used as a heat source of a heating device. Attempts have been made to use carbon-based resistance heating elements such as graphite heaters or carbon heaters.

A carbon-based resistance heating element generally has a rectangular cross section orthogonal to the longitudinal direction of the heating element, and has radiation directivity in two directions. Therefore, by adjusting the peak direction of the radiation intensity to the nip portion where the toner is fixed, it is possible to obtain a heating efficiency superior to that having no radiation directivity. In particular, the image fixing device disclosed in Patent Document 1 uses a combination of a sheet-like carbon-based resistance heating element having radiation directivity and a reflecting portion that reflects infrared radiation from the carbon-based resistance heating element, By concentrating infrared radiation in a narrow range of the rotating body that contacts and heats it, the heating efficiency of the paper through the rotating body is improved.

Japanese Patent Laying-Open No. 2008-33240 (FIG. 3)

  However, in the technique of Patent Document 1, the infrared radiation emitted from one surface of the heating element is directed directly to the nip portion where the toner is fixed, and the infrared radiation emitted from the other surface of the heating element is used. A reflection part is provided that reflects only locally at the nip part. Therefore, a part of infrared rays reflected by the reflecting portion is irradiated to the heating element itself, and the emitted infrared rays cannot be used efficiently.

  An object of the present invention is to provide a heat fixing device using a plate-like carbon-based resistance heating element having radiation directivity, which can efficiently heat and fix an unfixed image formed on a recording material. It is.

The heat fixing apparatus of the present invention includes a first rotating body and a second rotating body that is rotatable in a direction opposite to the first rotating body and forms a nip portion of a recording material between the first rotating body and the first rotating body. , look-containing carbon-based resistance heating element having a first and a second radiation surface, which has a linear shape extending in the rotation axis direction of the first rotating body, wherein it is contained in the first rotor first An unfixed image is provided by passing a recording material having an unfixed image formed in the nip portion, and a heat generating unit that heats the inner surface of the rotator, and a reflection part included in the first rotator. Is a heating and fixing device that heats and fixes the recording material to the recording material, wherein most of infrared radiation from the first radiation surface of the carbon-based resistance heating element forms the nip portion of the first rotating body. From the second radiation surface of the carbon resistance heating element. Most of the infrared radiation of the light is reflected by the reflecting portion, so that it is upstream of the first region in the rotation direction of the first rotating body and faces the center point of the nip portion in the first rotating body. The second region of the first rotating body that is continuous with the first region and downstream of the opposing point is irradiated.

According to the present invention, the first region including the region that forms the nip portion is heated by infrared radiation from the first surface of the carbon-based resistance heating element, and the second region other than the first region including the region that forms the nip portion. Is heated by infrared radiation from the second surface of the carbon-based resistance heating element. Then, most of the infrared radiation from the second surface can be reflected by the reflecting portion to efficiently promote the temperature rise in the second region, and when the recording material passes through the nip portion, the temperature of the nip portion is set. The recording material can be sufficiently raised and the recording material can be efficiently heated. As a result, it is possible to drive the heat fixing device with power saving.
In another aspect, the heat fixing device of the present invention is rotatable in the direction opposite to the first rotating body and the first rotating body, and forms a nip portion of a recording material between the first rotating body and the first rotating body. The first rotating body includes a second rotating body and a carbon-based resistance heating element having first and second radiation surfaces, and has a linear shape extending in the rotation axis direction of the first rotating body, and is included in the first rotating body. A heating unit that heats the inner surface of the first rotating body, and a reflecting portion included in the first rotating body, and passing a recording material on which an unfixed image is formed in the nip portion. A heating and fixing device that heat-fixes the unfixed image on the recording material, wherein infrared radiation from the first radiation surface of the carbon-based resistance heating element is reflected by the reflecting portion, whereby the first The first region including the region forming the nip portion of the rotating body is irradiated to Infrared radiation from the second radiation surface of the carbon-based resistance heating element is reflected by the reflecting portion, so that the first rotation is upstream of the first region with respect to the rotation direction of the first rotating body. The second region of the first rotating body that is continuous with the first region and is downstream of the opposing point that faces the center point of the nip portion in the body is irradiated.
In still another aspect, the heat fixing apparatus of the present invention is capable of rotating in a direction opposite to the first rotating body and the first rotating body, and forming a nip portion of a recording material between the first rotating body. And a carbon-based resistance heating element having first and second radiation surfaces, and has a linear shape extending in the rotation axis direction of the first rotation body, and the first rotation body includes A heating unit that is included and heats the inner surface of the first rotator, and a reflective portion that is included in the first rotator, and passes a recording material on which an unfixed image is formed in the nip portion. In the heat fixing apparatus for heat-fixing the unfixed image on the recording material, the infrared radiation from the first radiation surface of the carbon-based resistance heating element is reflected by the reflecting portion, whereby the first The first region including the region for forming the nip portion of one rotating body is irradiated. , Infrared radiation from the second radiation surface of the carbonaceous resistance heating element is, by reflecting by the reflection portion, and the first region is irradiated to the second region of different first rotating body.
At this time, a part of infrared radiation from the first radiation surface and the second radiation surface of the carbon-based resistance heating element may be emitted toward the first region and the second region, respectively.

  The first region and the second region do not rotate with the heating body or the first rotating body in a fixed coordinate system fixed outside the heating body or the first rotating body and the pressure body or the second rotating body, It means an area at a fixed position on the heating body or the first rotating body in the fixed coordinate system.

  A fixing auxiliary member that is included in the first rotating body and is in contact with or close to at least the first region and is irradiated with infrared radiation from the carbon-based resistance heating element and has a larger heat capacity than the first rotating body. Is preferably further provided. This makes it possible to heat the recording material more efficiently.

  According to the present invention, the region where the nip portion of the heating body is formed by infrared radiation from the first radiation surface of the carbon-based resistance heating element having the first and second radiation surfaces having high radiation intensity in at least two directions. When the recording material passes through the nip portion, the first region including the first region is heated and the second region upstream of the first region is heated by infrared radiation from the second radiation surface. The temperature of the recording material can be sufficiently increased, and the recording material can be efficiently heated. As a result, it is possible to drive the heat fixing device with power saving. The heat fixing apparatus of the present invention can be mounted on, for example, an on-demand high-speed color printer.

1 is a plan view of a heat fixing device according to a first embodiment of the present invention. It is sectional drawing of the heat fixing apparatus shown in FIG. It is sectional drawing of the heat fixing apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the heat fixing apparatus which concerns on the 3rd Embodiment of this invention.

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

<First Embodiment>
The heat fixing apparatus according to the first embodiment of the present invention is included in an image forming apparatus that forms an unfixed image on a sheet P as a recording material. As shown in FIGS. 1 and 2, the heating and fixing apparatus 1 according to the present embodiment includes a flexible cylindrical heating belt 10 as a heating body or a first rotating body, and a heating belt 10 below the heating belt 10. A pressure roller 20 serving as a pressure body or a second rotating body arranged and a heating element unit 30 included in the heating belt 10 are included. As will be described later, in addition to the heating element unit 30, the heating belt 10 includes a reflecting portion 40 having a concave surface and an arc-shaped piece 50 as a fixing auxiliary member (heat absorbing member). All members in the heat fixing apparatus 1 are formed longer than the width of the paper P. In FIG. 1, the heating element unit 30 that is in the heating belt 10 and is not actually visible is indicated by a solid line.

  The heating belt 10 is composed of a thin resin layer, a thin metal layer, or a laminate layer thereof. The surface of the pressure roller 20 is made of heat resistant rubber. The pressure roller 20 is rotationally driven around the shaft 21 counterclockwise in FIG. 2 by a drive mechanism (not shown) including a motor and gears. When the lowest point of the heating belt 10 comes into contact with the highest point of the pressure roller 20, the fixing region (nip portion, center point X) of the paper P on which an image is formed (direction perpendicular to the paper surface of FIG. 2). Is formed. The pressure roller 20 is biased upward by a biasing mechanism (not shown) including an elastic member so that an appropriate pressure is applied to the paper P at the nip portion. Therefore, the heating belt 10 receiving the rotational force from the pressure roller 20 is driven to rotate clockwise. The heat fixing device 1 according to the present embodiment fixes the toner on the paper P by the contact pressure between the heating belt 10 and the pressure roller 20 and the heat from the heating element unit 30.

  The paper P is transported to the left in FIG. 1 by a transport mechanism (not shown). Before reaching the nip portion, the toner image pattern transferred from the photosensitive drum (not shown) is adhered to the upper surface of the paper P in an unfixed state.

  The heating element unit 30 included in the heating belt 10 includes a graphite heater 31 which is a carbon-based resistance heating element having first and second radiation surfaces having high radiation intensity on both sides of a sheet, and the graphite heater 31. A cylindrical and transparent glass tube 32 which is a covering body to be included is included. The heating element unit 30 has a linear shape extending in the direction of the rotation axis of the heating belt 10, that is, the vertical direction on the paper surface of FIG. 1 (the direction orthogonal to the paper surface of FIG. 2). The central axis of the glass tube 32 is slightly below the center of the heating belt 10, that is, the rotation axis.

  The graphite heater 31 emits infrared rays when energized. The graphite heater 31 extends horizontally so that its center passes through the central axis of the glass tube 32. Therefore, both radiation surfaces 31a and 31b of the graphite heater 31 are horizontal surfaces, one radiation surface (second radiation surface) 31a faces upward, and the other radiation surface (first radiation surface) 31b Looking down. As described above, the heating element unit 30 is arranged symmetrically with respect to a vertical plane passing through the center of the heating belt 10.

  The infrared rays emitted from the radiation surface 31a of the graphite heater 31 have directivity. Specifically, the intensity of the emitted infrared light is the strongest in the direction from the center of the graphite heater 31 directly upward, and becomes weaker as it moves left and right from there, and is emitted from the graphite heater 31 in the horizontal direction. Infrared intensity is very weak. The infrared rays radiated from the radiation surface 31b of the graphite heater 31 have the same directivity as this. The graphite heater 31 emits the same amount of infrared rays from the radiation surface 31a and the radiation surface 31b.

  In the present embodiment, the first region A1 of the heating belt 10 including the center point X of the nip portion is a region where the nip portion is formed by infrared rays emitted from the radiation surface (first radiation surface) 31b of the graphite heater 31. Is heated via an arcuate piece 50 which is a fixing auxiliary member (heat absorbing member) provided corresponding to the first region A1 including

  The arc-shaped piece 50 is formed in substantially the same region range as the first region A1 including the region where the nip portion is formed, along the inner surface of the heating belt 10. The outer peripheral surface of the arc-shaped piece 50 is in contact with the first region A1 with a contact pressure that does not hinder the rotation of the heating belt 10 (or close to the heating belt 10 so as to be thermally coupled). Yes. Therefore, the arc-shaped piece 50 is irradiated with infrared rays emitted from the radiation surface (first radiation surface) 31b, whereby the arc-shaped piece 50 is stored with heat. The arc-shaped piece 50 is made of a material having a larger heat capacity than the heating belt 10. Therefore, by providing the arc-shaped piece 50, it is easy to relatively increase the heat storage amount in the first region A1 including the region where the nip portion is formed.

  In the present embodiment, most of infrared rays radiated from the radiation surface 31b are applied to the arc-shaped piece 50 provided in the first region A1 including the region that substantially forms the nip portion.

  The reflector 40 can reflect most of the infrared radiation from one radiation surface (second radiation surface) 31 a of the graphite heater 31 substantially toward one side of the inner surface of the heating belt 10. It has a shape. Infrared light reflected by the reflecting portion 40 is applied to the preheating region (second region) B1. The preheating region (second region) B1 is upstream of the first region A1 including the region where the nip portion is formed in the rotation direction of the heating belt 10 and is continuous with the first region A1.

  In the present embodiment, the upstream end of the preheating region (second region) B1 is downstream of the opposing point Y facing the center point X of the nip portion in the heating belt 10 with respect to the rotation direction of the heating belt 10 and is heated. With respect to the rotational direction, the center of the belt 10 is the upstream of the intermediate point Z located 90 ° from the opposite point Y.

  In addition, you may comprise so that the upstream of 1st area | region A1 and the downstream of preheating area | region (2nd area | region) B1 may overlap.

  As described above, when the graphite heater 31 is energized, the first region A1 including the region forming the nip portion of the heating belt 10 is heated by the infrared radiation from the radiation surface 31b and upstream of the first region A1. The preheating region (second region) B1 on the side is heated by infrared radiation from the radiation surface 31a. At this time, all of the infrared rays radiated from the radiation surface 31a and reflected by the reflecting portion are irradiated to the preheating region (second region) B1 on the upstream side of the first region A1, and are emitted from the radiation surface 31a. Infrared rays can be used efficiently. Therefore, the infrared radiation from the radiation surface 31a can be concentrated to promote the temperature increase in the preheating region (second region) B1. Further, when attention is paid to a certain part of the heating belt 10, the part includes a first region including a region where a nip portion is formed next as the heating belt 10 rotates after the region becomes the preheating region (second region) B <b> 1. Since it becomes area A1, when the paper P passes through the nip portion, the temperature of the nip portion can be sufficiently increased. In this way, the first region A1 and the preheating region (second region) B1 including the region where the nip portion is formed by the infrared radiation from the radiation surface 31b and the infrared radiation from the radiation surface 31a are individually heated. Thus, when the paper P enters the region where the nip portion is formed, the paper P can be efficiently heated to fix the toner to the paper P. As a result, the heat fixing device 1 can be driven with power saving.

  In the present embodiment, since the upstream end of the preheating region (second region) B1 is downstream of the opposing point Y and further upstream of the intermediate point Z than the opposing point Y, the preheating is performed. Compared to the case where the region (second region) does not reach the upstream of the intermediate point Z, the preheating region (second region) B1 can be sufficiently heated, and the paper P is efficiently heated. Is possible. In addition, the preheating area | region which made it so that the upstream end of preheating area | region (2nd area | region) B1 may be located in the downstream rather than the intermediate point Z by the heat absorption / release transmission characteristic of the heating belt 10 was made into the narrow area | region. (Second region) B1 may be intensively heated by infrared radiation from the radiation surface 31a.

  In addition, since the graphite heater 31 emits the same amount of infrared rays from the two radiation surfaces 31a and 31b, the worker is not aware of the difference between the two radiation surfaces 31a and 31b when attaching the heating element unit 30. That's it. Therefore, the attaching operation of the heating element unit 30 can be facilitated.

  Furthermore, since the preheating region (second region) B1 is continuous with the first region A1 including the nip portion, there is no period during which the portion of the heating belt 10 once heated by the graphite heater 31 is not heated, It is possible to heat the paper P more efficiently.

  In addition, since the heat fixing device 1 includes the arc-shaped piece 50 that is in contact with the first region A1 including the region where the nip portion is formed and has a larger heat capacity than the heating belt 10, a certain amount of time has elapsed since the start of operation. After that, the heat supply to the paper P is stably performed. As a result, the paper P can be heated more efficiently.

<Second Embodiment>
Next, a heat fixing apparatus 101 according to the second embodiment of the present invention will be described with reference to FIG. 3 mainly on differences from the first embodiment. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 3, in the heating and fixing apparatus 101 of the present embodiment, the heating element unit 130 included in the heating belt 10 has a center axis of the glass tube 132 obliquely rightward with respect to the center of the heating belt 10. It is arranged to be located below. The graphite heater 131 having the same shape as the graphite heater 31 in the first embodiment is inclined so that its center passes through the central axis of the glass tube 132 and its upper end is located inside the lower end. It is extended. Therefore, both radiation surfaces 131a and 131b of the graphite heater 131 are inclined surfaces, one radiation surface 131a faces obliquely upward and outward, and the other radiation surface 131b faces obliquely downward and inward. The infrared radiation direction of one radiation surface 131a is downstream from the opposing point Y, and the infrared radiation direction of the other radiation surface 131b is downstream from the center point X of the nip portion.

  The reflection unit 140 includes a concave portion 140a having a shape capable of reflecting a part of infrared radiation from the radiation surface 131a of the graphite heater 131 toward the inner surface of the heating belt 10, and one of infrared radiation from the radiation surface 131b. And a concave portion 140b having a shape capable of reflecting the portion toward the inner surface of the heating belt 10. The two recesses 140a and 140b are connected to each other. The infrared light reflected by the recess 140a is applied to the preheating region (second region) B2, and the infrared light reflected by the recess 140b is applied to the arcuate piece 50 located in the first region A2 including the region forming the nip portion.

  In the present embodiment, the first region A2 of the heating belt 10 including the center point X of the nip portion is heated via the arc-shaped piece 50 by infrared rays radiated from the radiation surface 131b of the graphite heater 131. The area A2 including the area where the nip portion is formed corresponds to the same range as the area A1 including the area where the nip portion is formed in the first embodiment. In the present embodiment, most of the infrared rays radiated from the radiation surface 131b are reflected directly and the remaining infrared rays radiated from the radiation surface 131b are reflected by the concave portion 140b and irradiated to the arc-shaped piece 50 together.

  The preheating region (second region) B2 is upstream of the first region A2 including the nip portion in the rotation direction of the heating belt 10 and is continuous with the first region A2. In the present embodiment, most of the infrared rays radiated from the radiation surface 131a are reflected directly and the remaining infrared rays radiated from the radiation surface 131a are reflected by the recess 140a, and are both preheated regions (second regions) B2. Is irradiated. The upstream end of the preheating region (second region) B <b> 2 is downstream from the facing point Y and upstream from the intermediate point Z in the rotation direction of the heating belt 10.

  As described above, when the graphite heater 131 is energized, the first region A2 including the region that forms the nip portion of the heating belt 10 is heated by the infrared radiation from the radiation surface 131b and the preheating region (second heating region). Region B2 is heated by infrared radiation from the radiation surface 131a. At this time, all the infrared rays emitted from the emission surface 131a are irradiated to the preheating region (second region) B2 on the upstream side of the first region A2, and the infrared rays emitted from the emission surface 131b are efficiently emitted. Can be used. Therefore, it is possible to concentrate the infrared radiation from the radiation surface 131a and promote the temperature rise in the preheating region (second region) B2. Further, when attention is paid to a certain part of the heating belt 10, the part includes a first region including a region where a nip portion is formed next as the heating belt 10 rotates after the region becomes the preheating region (second region) B2. Since it becomes area A2, when the paper P passes through the nip portion, the temperature of the nip portion can be sufficiently increased. As described above, the preheating region (second region) B2 is provided on the heating belt 10, and the first region A2 including the nip portion and the preheating region (infrared radiation from the radiation surface 131b and the infrared radiation from the radiation surface 131a) and the preheating region ( By individually heating the second region B2, it is possible to efficiently heat the paper P and fix the toner to the paper P when the paper P enters the nip portion. As a result, the heat-fixing device 101 can be driven with power saving. Furthermore, since the infrared radiation direction of one radiation surface 131a is downstream from the opposing point Y, the infrared radiation direction of the other radiation surface 131b is downstream from the center point X of the nip portion. Compared to the first embodiment, the preheating region (second region) B2 can be heated more effectively. In addition, according to the present embodiment, the same technical effect as that of the first embodiment can be obtained. In addition, according to the present embodiment, the same technical effect as that of the first embodiment can be obtained.

<Third Embodiment>
Next, a heat fixing apparatus 201 according to the third embodiment of the present invention will be described with reference to FIG. 4 mainly on differences from the first embodiment. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 4, in the heat fixing apparatus 201 of the present embodiment, the heating element unit 230 included in the heating belt 10 has the central axis of the glass tube 232 as in the second embodiment. Is arranged so as to be located diagonally to the lower right of the center of the heating belt 10. The graphite heater 231 having the same shape as the graphite heater 131 in the first embodiment is inclined so that its center passes through the central axis of the glass tube 232 and its upper end is located inside the lower end. It is extended. Therefore, both radiation surfaces 231a and 231b of the graphite heater 231 are inclined surfaces, one radiation surface 231a faces obliquely upward and outward, and the other radiation surface 231b faces obliquely downward and inward. The infrared radiation direction of one radiation surface 231a is downstream from the opposing point Y, and the infrared radiation direction of the other radiation surface 231b is downstream from the center point X of the nip portion.

  The reflecting mirror 240 includes a concave portion 140a having a shape capable of reflecting a part of infrared radiation from the radiation surface 231a of the graphite heater 231 toward the inner surface of the heating belt 10, and one of infrared radiation from the radiation surface 231b. And a concave portion 240b having a shape that can reflect the portion toward the inner surface of the heating belt 10. The two recesses 240a and 240b are separated and separated. Both the infrared light reflected by the concave portion 240a and the infrared light reflected by the concave portion 240b are applied to the arc-shaped piece 250. In the present embodiment, the arc-shaped piece 250 has an inner surface of the heating belt 10 within the same range as a combination of the first region A3 including a region for forming a nip portion described later and the preheating region (second region) B3. Are arranged along.

  In the present embodiment, the first region A3 of the heating belt 10 including the center point X of the nip portion is heated via the arc-shaped piece 250 by infrared rays radiated from the radiation surface 231b of the graphite heater 231. The nip region A3 corresponds to the same range as the nip region A1 in the first embodiment. In the present embodiment, most of the infrared rays radiated from the radiation surface 231b are reflected directly and the remaining infrared rays radiated from the radiation surface 231b are reflected by the recess 240b and are irradiated to the downstream region of the arc-shaped piece 250 together. The

  The preheating region (second region) B3 that is upstream of the first region A3 including the region that forms the nip portion in the rotation direction of the heating belt 10 and that is continuous with the first region A3 is a radiation surface 231a of the graphite heater 231. It is heated via the arc-shaped piece 250 by the infrared rays emitted from it. In the present embodiment, most of the infrared rays radiated from the radiation surface 231a are reflected directly and the remaining infrared rays radiated from the radiation surface 231a are reflected by the concave portion 240a and are irradiated on the upstream region of the arcuate piece 250 together. The The upstream end of the preheating region (second region) B3 is downstream of the facing point Y and upstream of the intermediate point Z in the rotation direction of the heating belt 10.

  As described above, when the graphite heater 231 is energized, the first region A3 including the region where the nip portion of the heating belt 10 is formed is heated by the infrared radiation from the radiation surface 231b and the preheating region (second heating region). Region B3 is heated by infrared radiation from the radiation surface 231a. At this time, all of the infrared rays irradiated from the radiation surface 231a and reflected by the reflecting portion 240a are irradiated to the preheating region (second region) B3 on the upstream side of the first region A3 including the nip portion. The infrared rays emitted from the radiation surface 231a can be used efficiently. Therefore, it is possible to concentrate the infrared radiation from the radiation surface 231a and promote the temperature rise in the preheating region (second region) B3. Further, when attention is paid to a certain portion of the heating belt 10, the portion becomes the preheating region (second region) B3 and then becomes the nip portion as the heating belt 10 rotates, so that the sheet P is nipped. When passing through the portion, the temperature of the nip portion can be sufficiently raised. As described above, the preheating region (second region) B3 is provided in the heating belt 10, and the first region A3 including the nip portion and the preheating region (infrared radiation from the radiation surface 231b and infrared radiation from the radiation surface 231a) and the preheating region ( By individually heating the second region B3, when the paper P enters the center point X of the nip portion, it is possible to efficiently heat the paper P and fix the toner to the paper P. As a result, the heat fixing device 201 can be driven with power saving. Furthermore, since the infrared radiation direction of one radiation surface 231a is downstream from the opposing point Y, and the infrared radiation direction of the other radiation surface 231b is downstream from the center point X of the nip portion, As compared with the first embodiment, the preheating region (second region) B3 can be heated more effectively. In addition, according to the present embodiment, the same technical effect as that of the first embodiment can be obtained.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made to the above-described embodiments as long as they are described in the claims. It is possible to apply. For example, in the above-described embodiment, a graphite heater is used as the carbon-based resistance heating element, but other carbon-based resistance heating elements such as a carbon heater can be used. In the above-described embodiment, the carbon-based resistance heating element having a sheet shape is used. In the present invention, the first and second radiations having high irradiation intensity in at least two directions are used as the carbon-based resistance heating element. You may use what has the arbitrary shape which has a surface.

  The first rotating body is not limited to the heating belt as in the above-described embodiment, and a roller type may be used. In the embodiment described above, the arcuate piece which is a fixing auxiliary member is used, but this may not be used. Further, the heating element unit may have a plurality of carbon-based resistance heating elements. In this case, if at least one surface of the plurality of carbon-based resistance heating elements heats the first region including the nip portion and the other at least one surface heats the upstream preheating region (second region). Good.

1 Heating Fixing Device 10 Heating Belt (Heating Body, First Rotating Body)
20 Pressure roller (pressure body, second rotating body)
21 Shaft 30 Heating unit 31 Graphite heater 31a, 31b Radiation surface 32 Glass tube 40 Reflecting mirror 50 Arc-shaped piece (fixing auxiliary member)
X Nip part center point A1 First area B1 including nip part Preheating area (second area)
P paper

Claims (5)

A first rotating body;
A second rotator that is rotatable in the opposite direction to the first rotator and forms a nip portion of a recording material with the first rotator;
Look containing a carbon-based resistance heating element having a first and a second radiation surface, which has a linear shape extending in the rotation axis direction of the first rotating body, wherein it is contained in the first rotator first A heating unit for heating the inner surface of the rotating body ;
A reflection part included in the first rotating body,
A heating and fixing device that heat-fixes the unfixed image on the recording material by passing a recording material on which an unfixed image is formed in the nip portion;
Most of infrared radiation from the first radiation surface of the carbon-based resistance heating element is emitted toward a first region including a region that forms the nip portion of the first rotating body,
Most of the infrared radiation from the second radiation surface of the carbon-based resistance heating element is reflected by the reflecting portion, thereby being upstream of the first region with respect to the rotation direction of the first rotating body. Heat fixing by irradiating a second area of the first rotating body which is downstream of an opposing point facing the center point of the nip portion in the first rotating body and which is continuous with the first area. apparatus. A first rotating body;
A second rotator that is rotatable in the opposite direction to the first rotator and forms a nip portion of a recording material with the first rotator;
The first rotation body includes a carbon-based resistance heating element having first and second radiation surfaces, has a linear shape extending in a rotation axis direction of the first rotation body, and is included in the first rotation body. A heating unit that heats the inner surface of the body;
A reflection part included in the first rotating body,
A heating and fixing device that heat-fixes the unfixed image on the recording material by passing a recording material on which an unfixed image is formed in the nip portion;
Infrared radiation from the first radiation surface of the carbon-based resistance heating element is applied to a first region including a region that forms the nip portion of the first rotating body by being reflected by the reflection unit,
Infrared radiation from the second radiation surface of the carbon-based resistance heating element is reflected by the reflecting portion, thereby being upstream of the first region in the rotation direction of the first rotating body and the first. The heating and fixing device irradiates a second area of the first rotating body, which is downstream of an opposing point facing the center point of the nip portion in the rotating body, and is continuous with the first area. A first rotating body;
A second rotator that is rotatable in the opposite direction to the first rotator and forms a nip portion of a recording material with the first rotator;
The first rotation body includes a carbon-based resistance heating element having first and second radiation surfaces, has a linear shape extending in a rotation axis direction of the first rotation body, and is included in the first rotation body. A heating unit that heats the inner surface of the body;
A reflection part included in the first rotating body,
A heating and fixing device that heat-fixes the unfixed image on the recording material by passing a recording material on which an unfixed image is formed in the nip portion;
Infrared radiation from the first radiation surface of the carbon-based resistance heating element is applied to a first region including a region that forms the nip portion of the first rotating body by being reflected by the reflection unit,
Infrared radiation from the second radiation surface of the carbon-based resistance heating element is reflected by the reflecting portion, and is irradiated onto a second region of the first rotating body different from the first region. A heat-fixing device characterized. A part of infrared radiation from the first radiation surface and the second radiation surface of the carbon-based resistance heating element is emitted toward the first region and the second region, respectively. The heat fixing device according to claim 2. A fixing auxiliary member that is included in the first rotating body and is in contact with or close to at least the first region and is irradiated with infrared radiation from the carbon-based resistance heating element and has a larger heat capacity than the first rotating body. heat fixing device according to any one of claims 1 to 4, characterized in that it further comprises a.

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