JP2002023559A - Heat fixing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actualize a heat fixing device which can prevent the temperature of bearing parts at both ends of a heat roller from rising, increase the reliability of printing operation, prolong the life of a unit, and effectively use waste heat. SOLUTION: This heat fixing device which is used for the fixation part of an image forming device forming a toner image on a recorded material and fixes an unfixed toner image carried on the recorded material through heat fixation is equipped with a heat roller 2 and a press-contacting roller 3 which faces the heat roller and is pressed against it; and the heat roller 2 or press-contact roller 3 has an installed loop type meandering thin heat pipe 6 which is variable in contact area. As an example, the loop type meandering thin heat pipe 6 which is processed into a plane is installed on the internal surface of the heat roller 2 by sticking, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device provided in an image forming apparatus such as a printer, an electrophotographic copying machine, a facsimile, and a plotter. The present invention relates to a heat fixing device having a configuration in which a problem that a bearing portion is heated to a high temperature by heat to be applied and heat energy can be effectively used, and an image forming apparatus provided with the heat fixing device.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus such as a printer, an electrophotographic copying machine, a facsimile, a plotter or the like, a latent image is formed on an image carrier such as a photoreceptor, and the latent image is formed into a toner for developing means. The toner image on the image carrier is transferred to transfer paper, postcard, OHP
After the image is transferred to a recording material such as a sheet, the unfixed toner image carried on the recording material is fixed using heat fixing in a fixing unit to form a fixed image. Used as a fixing unit, as a thermal fixing device for fixing the unfixed toner image carried on the recording material using thermal fixing, a heating roller, a pressure roller facing the heating roller and pressure bonding, comprising: Inserting a recording material between a heating roller and a pressure roller, and fixing an unfixed toner image to the recording material by applying heat and pressure in a contact area between the roller and the recording material called a nip portion. It has been known.

In a heat fixing device having a heating roller and a pressure roller as described above, particularly when a recording material such as a postcard is continuously fed, only a part of the heating roller is applied to the recording material. Because of the contact, the temperature of the contact portion decreases, but the temperature of the portion other than the contact portion becomes too high, and there is a problem that the fixing efficiency of the heating roller becomes uneven. To cope with this problem, Japanese Patent Application Laid-Open No. 4-124688 discloses a technique for suppressing excess heat generated in a heating roller by using a plurality of halogen lamps of an appropriate length provided for each paper size.
There is disclosed a technique of controlling a heat area applied to a heating roller by switching and using the sheet for each sheet size. Japanese Patent Application Laid-Open No. H10-142983 discloses a technique in which a heat absorbing plate is brought into contact with both ends of a heating roller, and heat absorbed by the plate is discharged to the outside of the housing.

[0004]

Among the above-mentioned prior arts, in the conventional system in which a plurality of halogen lamps are switched and used, it is necessary to install a lamp which is hardly used as a mechanism, which increases the cost. I will. In addition, the method in which the heat absorbing plate is brought into contact with both ends of the heating roller is good for reducing the temperature of the end portion of the heating roller, but lacks the viewpoint of reusing the heat absorbed by the heat absorbing plate, and is not energy efficient. There is a problem in thermal conductivity in terms of utilization.
There is also a method of using a heat pipe to radiate heat to locally high temperature parts. However, conventional heat pipes are difficult to process and have anisotropy in the direction of heat conduction. There was a problem that it was not possible to dissipate heat.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a mechanism for efficiently disposing heat at low cost, and a heat fixing device capable of effectively utilizing heat. It is an object of the present invention to provide an apparatus and an image forming apparatus using the heat fixing device. More specifically, in an image forming apparatus using thermal fixing, when printing a narrow recording material continuously, by preventing the temperature of the bearings at both ends of the heating roller of the fixing unit from rising, the reliability of the printing operation is improved. To provide a heat fixing device capable of increasing the resilience, prolonging the life of the unit, and effectively using the exhaust heat, and improving the reliability and using the energy effectively by using the heat fixing device. It is intended to provide.

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 is used in a fixing section of an image forming apparatus for forming a toner image on a recording material, and the recording material is In a thermal fixing device for fixing a carried unfixed toner image using thermal fixing, a heating roller, a pressure roller opposed to and pressed against the heating roller, the contact area with the heating roller or the pressure roller, This is a configuration in which a changeable loop-shaped meandering thin tube heat pipe is installed. That is, in the present invention, a heat pipe is installed on a heating roller or a pressure roller as a mechanism for efficiently discharging and utilizing heat at a low cost. This uses a loop-shaped meandering thin tube heat pipe as described in Japanese Patent No. 328881. With conventional heat pipes, it is difficult to process into a planar shape, and even if processed, there is a restriction on the direction of heat reception (heat absorption) and heat conduction of the heat radiating section. Although it could not be used as a member for controlling conduction, the loop-shaped meandering thin tube heat pipe used in the present invention is easier to process in a plane shape than a conventional heat pipe, and has a higher thermal conductivity. Are good, there is almost no anisotropy in thermal conductivity, and they are small and lightweight, so that the invention described in the following claims can be made.

More specifically, the invention according to claim 2 is characterized in that, in the heat fixing device according to claim 1, a loop-shaped meandering thin tube heat pipe processed into a planar shape is installed on the inner surface of the heating roller. And More specifically, the invention according to claim 2 includes a heating roller and a pressure roller facing and pressing against the heating roller, and a recording material carrying an unfixed toner image (for example, a transfer sheet, a postcard,
OHP sheet) is inserted between the heating roller and the pressure roller, and heat and pressure are applied to fix the unfixed toner to the recording material by applying heat and pressure in a contact area between the roller and the recording material called a nip portion. In the fixing device, a heat source (eg, halogen lamp, heating wire, etc.)
A loop-shaped meandering thin-tube heat pipe processed into a planar shape is attached to the inner surface of a heating roller having, for example, an adhesive.

A third aspect of the present invention is the heat fixing device according to the first aspect, wherein a loop-shaped meandering thin tube heat pipe formed into a planar shape is provided on an inner surface of the pressure roller. More specifically, the invention according to claim 3 includes a heating roller, and a pressure roller facing and pressing against the heating roller, and a recording material carrying an unfixed toner image (for example, a transfer sheet, a postcard, OHP sheet) is inserted between the heating roller and the pressure roller, and heat and pressure are applied to fix the unfixed toner to the recording material by applying heat and pressure in a contact area between the roller and the recording material called a nip portion. In the fixing device, a loop-shaped meandering thin-tube heat pipe processed into a planar shape is attached to the inner surface of a pressure roller facing the heating roller by attaching or the like.

However, in the above-mentioned inventions according to the second and third aspects, only the means for equalizing the heat inside the heating roller or the pressure roller is used. For example, when printing a large amount of paper, a means for equalizing the temperature of the surface layer of both rollers may be required. Therefore, in the present application, a device expressed in the following claims is implemented.

According to a fourth aspect of the present invention, in the thermal fixing device according to the first aspect, a loop type meandering thin tube heat pipe provided with a unit capable of controlling separation and contact with a partial area of the heating roller is provided. It is characterized by doing. More specifically, the invention according to claim 4 includes a heating roller and a pressure roller facing and pressing against the heating roller, and a recording material carrying an unfixed toner image (for example, a transfer paper, a postcard, OHP sheet) is inserted between the heating roller and the pressure roller, and heat and pressure are applied to fix the unfixed toner to the recording material by applying heat and pressure in a contact area between the roller and the recording material called a nip portion. In the fixing device, a structure is provided in which a loop-shaped meandering thin tube heat pipe is arbitrarily separated from and brought into contact with a partial area of the heating roller.

According to a fifth aspect of the present invention, in the thermal fixing device of the fourth aspect, a loop-shaped meandering thin-tube heat pipe having a shape or a mechanism capable of controlling a contact area with the heating roller is provided. Features. That is, a heat fixing device according to a fifth aspect is configured such that, in addition to the configuration of the fourth aspect, the loop type meandering thin tube heat pipe is provided with a shape or a mechanism capable of arbitrarily adjusting a range of contact with the heating roller. is there.

According to a sixth aspect of the present invention, in the thermal fixing device according to the fourth or fifth aspect, a heat radiating portion of the loop type meandering thin tube heat pipe is connected to a recording material storage portion. I do. That is, in the heat fixing device according to the sixth aspect, in addition to the configuration according to the fourth or fifth aspect, the radiating end of the loop-shaped meandering thin tube heat pipe is connected to a part of the recording material storage portion, and excess heat is removed. It is configured to have a mechanism for conducting.

Next, the invention according to claim 7 is based on claims 4 and 5.
Or the heat fixing device according to 6, wherein the heating roller and the loop-shaped meandering thin tube heat pipe are in contact with each other via a roller having a high thermal conductivity material and a low heat capacity, and by changing the length of inserting the roller, The recording material fixing area of the heating roller is adjusted. That is, in the heat fixing device according to the seventh aspect, in addition to the configuration of the fourth, fifth, or sixth aspect, the heating roller contacts the loop-shaped meandering thin-tube heat pipe via a roller having a small heat capacity made of a material having a high thermal conductivity. This is a configuration having a mechanism for performing

Next, the invention according to claim 8 relates to claim 4,
In the thermal fixing device described in 5, 6, or 7, a controller that controls a separation contact or a contact area between the loop-shaped meandering thin-tube heat pipe and the heating roller portion by setting an image forming condition input from the operation unit by a user. It is characterized by having. That is, in the heat fixing device according to the eighth aspect, in addition to the configuration of the fourth, fifth, sixth, or seventh aspect,
The effective length of thermocompression bonding on the heating roller is calculated by setting the image forming conditions such as the paper size and the number of images set by the user, and the separation or contact area between the loop type meandering thin tube heat pipe and the heating roller is determined. And a controller for performing the control.

The invention according to claim 9 is the invention according to claims 4, 5, 6
Or in the heat fixing device according to 7, wherein a controller that controls a separated contact or a contact area between the loop-shaped meandering thin tube heat pipe and the heating roller portion by a temperature detected by a temperature sensor installed in a bearing portion of the heating roller. It is characterized by having. That is, in the thermal fixing device according to the ninth aspect, in addition to the configuration according to the fourth, fifth, sixth, or seventh aspect, the heat on the heating roller is determined by a temperature detected by a temperature sensor installed on a bearing portion of the heating roller. The configuration includes a controller that calculates the effective length of the pressure bonding and determines and controls the effective contact area between the loop-shaped meandering thin tube heat pipe and the heating roller.

The heat fixing apparatus according to the present invention has been described above. In the tenth aspect of the present invention, a latent image is formed on an image carrier, and the latent image is developed by toner of a developing unit. Forming an image, transferring the toner image on the image carrier to a recording material, and fixing the unfixed toner image carried on the recording material using heat fixing in a fixing unit. A fixing unit is provided with the heat fixing device according to any one of claims 1 to 9.
That is, in the image forming apparatus according to the tenth aspect, the fixing unit includes the heat fixing device according to any one of the first to ninth aspects. Even in the case of continuous printing, the temperature of the bearings at both ends of the heating roller of the fixing unit can be prevented by using a loop type meandering thin tube heat pipe, so the reliability of the printing operation is increased and the life of the unit is extended, In addition, it is possible to realize an image forming apparatus that can effectively use waste heat (energy).

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction, operation and operation of a heat fixing device according to the present invention and an image forming apparatus provided with the heat fixing device will be described in detail with reference to the illustrated embodiments. Figure 1
1 is a schematic configuration diagram of an image forming apparatus showing one embodiment of the present invention. In the image forming apparatus 100 shown in FIG. 1, an image carrier 101 such as a photoconductive photoreceptor rotates clockwise as indicated by an arrow in FIG.
After the surface is uniformly charged, the image information of the document 110 is read by the optical system 102 to form a latent image on the image carrier 101. The latent image formed on the image carrier 101 is developed by the toner 105 supplied from the developing roller 104a of the developing unit 104 to be visualized. Then, the toner image on the image carrier 101 is transferred by a transfer unit 107 to a recording material (for example, image transfer paper) 106 fed from a storage unit (not shown), and adheres to the recording material 106. The recording material 106 carrying the unfixed toner image is conveyed to the heat fixing device 1, and in the heat fixing device 1, the nip portion 4 between the heating roller 2 and the pressure roller facing the heating roller 2 and pressed against the heating roller 2. The toner 105 is fixed on the recording material 106 by heat and pressure. On the other hand, the residual toner of the image carrier 101 after the transfer of the toner image is removed by the cleaning unit 108, and the residual charge is removed by the charge removing unit 109.

In the image forming apparatus having the structure shown in FIG.
The heat fixing device 1 has a configuration including a heating roller 2 and a pressure roller 3 facing and pressing the heating roller 2. In the present invention, the contact area of the heating roller 2 or the pressure roller 3 can be changed. A loop type meandering thin tube heat pipe is provided.
0). Hereinafter, specific examples thereof will be described.

FIG. 2 is a schematic view showing the configuration of a heat fixing device according to an embodiment of the present invention. A loop-shaped meandering thin-tube heat pipe 6 is formed on the inner surface of a heating roller 2 of the heat fixing device 1. (Claim 2). That is, in the present embodiment, the heating roller 2 is covered by a loop-shaped meandering thin tube heat pipe 6 in which the periphery of the halogen lamp 5 at the center is processed into a planar shape, and the periphery thereof is a ceramic material 7.
It is structured to be covered by. Since the meandering thin tube heat pipe 6 has a small anisotropy in the heat conduction direction, it is hardly affected by the rotation of the heating roller 2.
The surface temperature of the heating roller 2 can be kept uniform.

FIG. 3 is a schematic structural view of a heat fixing device according to another embodiment of the present invention. A loop-shaped meandering thin tube heat pipe is formed on the inner surface of a pressure roller 3 of the heat fixing device 1. 6 (claim 3). That is, in the present embodiment, a loop-shaped meandering thin tube heat pipe 6 having a planar shape is provided concentrically inside the pressure roller 3 facing the heating roller 2, and an elastic member such as rubber is provided on the surface thereof. I have. In the case of the present embodiment, the temperature of the pressure roller 3 is homogenized by the loop-shaped meandering thin tube heat pipe 6, and the surface temperature of the heating roller 2 in contact with the pressure roller 3 can be homogenized.

FIG. 4 is a schematic structural view of a heat fixing device according to still another embodiment of the present invention. The configuration is such that a loop-shaped meandering thin-tube heat pipe 9 provided with: More specifically, in FIG. 4, a recording material 106 such as an image transfer sheet is used.
Is inserted between the heating roller 2 and the pressure roller 3, and the unfixed toner image carried on the recording material 106 is fixed on the recording material 106 by heat and pressure. The surface of 2 is heated by an internal halogen lamp (not shown). At this time, when the recording material 106 has a small paper size such as a postcard, the recording material 106 passes through one end of the heating roller 2 and the pressure roller 3, but in the present embodiment, the recording material 106 does not contact. A heat absorbing portion 10a of a loop-shaped meandering thin tube heat pipe 9 capable of controlling contact and separation is arranged in the region 8, and a mechanism (not shown) capable of arbitrarily having contact with the region 8 described above.
It has a structure with. The loop-shaped meandering thin tube heat pipe 9 is extremely easy to process, and has less anisotropy in the direction of heat conduction as compared with the conventional heat pipe.
It is configured such that it may be processed into a roller shape and brought into contact with the heating roller 2. The heat absorbed by the contact with the heating roller 2 is discharged by the heat radiating portion 10 b of the loop-shaped meandering thin-tube heat pipe 9.

FIG. 5 is a schematic structural view of a heat fixing device showing still another embodiment of the present invention. In addition to the structure similar to that of FIG. Or a loop type meandering thin tube heat pipe 9 having a mechanism
(Claim 5). More specifically, in the present embodiment, in addition to a mechanism (not shown) for bringing the loop-shaped meandering thin tube heat pipe 9 into and out of contact with the heating roller 2, the loop-shaped meandering thin tube heat pipe 9 is connected to the shaft of the heating roller 2. The heat absorbing portion 10a of the loop-shaped meandering thin-tube heat pipe 9 has a structure that can slide while contacting on the heating roller 2, and is configured to slide with the heating roller 2 by an arbitrary length. It has a contactable structure.

FIG. 6 is a schematic diagram showing a main portion of an image forming apparatus according to still another embodiment of the present invention. In addition to the structure similar to that of the heat fixing device 1 shown in FIG. The heat radiation portion 10b of the meandering thin tube heat pipe 9 is connected to the storage portion 11 of the recording material 106 (claim 6). More specifically, in this embodiment, the excess heat on the heating roller 2 absorbed by the heat absorbing portion 10a of the loop-shaped meandering thin tube heat pipe 9 is transmitted to the heat radiating portion 10a of the loop-shaped meandering thin tube heat pipe 9. But
The heat radiating portion 10b is connected to the storage portion 11 of the recording material 106 via a member having high thermal conductivity or the like. Normally, the storage section 11 of the recording material 106 has a sufficient heat capacity, so that the temperature does not locally rise. Also, the storage unit 11
Usually contains a recording material 106 such as image transfer paper, but the heat transmitted by the heat radiating portion 10b warms the recording material 106 and evaporates excess water contained in the recording material 106. Since it has the function, the exhaust heat of the heating roller 2 can be effectively used.

FIG. 7 is a schematic structural view of a heat fixing device showing still another embodiment of the present invention. In addition to the same structure as the heat fixing device 1 of FIG. 4, FIG. 5 or FIG. The roller 2 and the loop-shaped meandering thin tube heat pipe 9 are in contact with each other via a roller 12 having a high thermal conductivity material and a low heat capacity,
The recording material fixing area of the heating roller 2 is adjusted by changing the length of inserting the roller 12 (claim 7). More specifically, in this embodiment, the loop-shaped meandering thin-tube heat pipe 9
The heat absorbing portion 10a has the same length as the long axis portion of the heating roller 2 and is installed close to the heating roller 2. Heating roller 2 and loop type meandering thin tube heat pipe 9
Small rollers 1 having good heat conductivity and low heat capacity, such as bronze material, between the heat absorbing portions 10a.
2 is inserted, and the heat of the heating roller 2 is transmitted to the heat absorbing portion 10 a of the loop-shaped meandering thin tube heat pipe 9 through the small roller 12. At this time, the roller 12 is arbitrarily movable by a slide mechanism (not shown) in parallel with the long axis of the heating roller 2. And it has a structure in which the size of the contact heat area can be controlled by the moving distance of the small roller 12.

FIG. 8 is an explanatory view of a heat fixing device showing a further embodiment of the present invention and a schematic configuration of a control system thereof. The heat fixing device shown in FIG. 4, FIG. 5, FIG. 6 or FIG. In addition to the same configuration as that of the first embodiment, the controller 14 controls the separation contact or the contact area between the loop-shaped meandering thin-tube heat pipe 9 and the heating roller 2 by setting the image forming conditions input from the operation unit 16 by the user. (Claim 8). More specifically,
In a case where the image forming apparatus is a copying machine, in this embodiment, when a user using the copying machine inputs the paper size and the number of copies using the operation panel 16, the input value is set to a preset “threshold”. Is exceeded, a control command is output from the control CPU (central processing unit comprising a microcomputer) of the controller 14 to the heat fixing device 1, and
By controlling a mechanism 13 (or a mechanism for changing a contact area between the loop type meandering thin tube heat pipe 9) and the heating roller 2 so as to separate and contact the loop type meandering thin tube heat pipe 9, the heat absorbing portion 10a of the loop type meandering thin tube heat pipe 9 is brought into contact with the heating roller 2. It has a configuration. Therefore, the separation condition, the contact area, and the like between the loop-shaped meandering thin-tube heat pipe 9 and the heating roller 2 are controlled by the copying condition input from the operation panel 16 or the like, so that more appropriate operating conditions can be set.

FIG. 9 is an explanatory view showing a schematic configuration of a heat fixing device and a control system thereof according to still another embodiment of the present invention. The heat fixing device shown in FIG. 4, FIG. 5, FIG. 6 or FIG. In addition to the configuration similar to 1, the separated contact or contact area between the loop type meandering thin tube heat pipe 9 and the heating roller 2 is determined by the temperature detected by the temperature sensor 15 installed in the bearing of the heating roller 2. Controller 14 to control
(Claim 9) More specifically, in the present embodiment, a temperature sensor 15 is installed on a bearing portion of the heating roller 2, and the temperature detected by the temperature sensor 15 is If the threshold value is exceeded, a control CPU of the controller 14 (central processing unit including a microcomputer)
A control command is output to the heat fixing device 1 to control a mechanism 13 (or a mechanism for changing the contact area between both) of the loop-shaped meandering thin-tube heat pipe 9 to the heating roller 2, so that the heating roller 2 is The heat absorbing portion 10a of the meandering thin tube heat pipe 9 is configured to be in contact with the heat absorbing portion 10a. Therefore, when the paper is continuously passed and the size of the recording material 106 is smaller than the size of the heating roller 2, the temperature of the bearing portion increases, but the controller 14 detects the temperature increase with the temperature sensor 15. Since the excess heat is exhausted by controlling the separation contact and the contact area between the loop-shaped meandering thin tube heat pipe 9 and the heating roller 2, the temperature rise of the bearing portion can be kept within a certain range.

[0027]

As described above, according to the first aspect of the present invention, a loop-shaped meandering thin tube heat pipe having higher workability and less heat conduction anisotropy than the conventional heat pipe is used. Since the loop-shaped meandering thin tube heat pipe is provided on the heating roller or the pressure roller, the fixing temperature can be made uniform, and a heat fixing device that can effectively use waste heat can be realized. . According to the second aspect of the present invention, in the thermal fixing device according to the first aspect, a loop-shaped meandering thin-tube heat pipe formed into a planar shape is attached to the inner surface of the heating roller by, for example, attaching. The effect of being able to provide a heating roller of a heat fixing device in which the surface temperature is kept uniform can be obtained. Thus, it is possible to prevent non-uniform fixability due to a temperature drop in a part of the heating roller, and to suppress image deterioration such as a printed image or a copied image. According to the third aspect of the present invention, in the heat fixing device according to the first aspect, the inner surface of the pressure roller includes:
The configuration is such that the loop-shaped meandering thin tube heat pipe processed into a planar shape is installed by sticking, etc., so the surface temperature of the pressure roller can be homogenized, and the temperature of the contacting heating roller can be homogenized. Thus, similarly to the second aspect, it is possible to obtain an effect that it is possible to provide a heating roller of a heat fixing device in which the surface temperature is kept more uniform. Thus, it is possible to prevent non-uniform fixability due to a temperature drop in a part of the heating roller, and to suppress image deterioration such as a printed image or a copied image.

According to a fourth aspect of the present invention, there is provided the heat fixing device according to the first aspect, wherein the loop type meandering thin tube heat pipe includes a unit capable of controlling the separation and contact of a part of the heating roller. In particular, A
In the fixing section of an image forming apparatus such as a copying machine or a printer that can print large paper of 3 or more sizes, a loop type meandering thin tube heat pipe that can be separated from and contacted with a part of the heating roller is installed, and small size such as postcards By contacting this loop type meandering thin tube heat pipe with the non-passing area of the heating roller during continuous paper feeding of the recording material, the local abnormal rise in surface temperature is suppressed, The effect that deterioration can be prevented and printing can be stabilized can be obtained. According to the fifth aspect of the present invention, in the thermal fixing device according to the fourth aspect, a loop-shaped meandering thin-tube heat pipe having a shape or a mechanism capable of controlling a range of contact with the heating roller is provided. By keeping the same effect as that of the fourth aspect and controlling the area of the loop-shaped meandering thin tube heat pipe to be brought into contact, the same effect can be applied to printing of various paper sizes. be able to.

According to a sixth aspect of the present invention, in the thermal fixing device according to the fourth or fifth aspect, the heat radiating portion of the loop type meandering thin tube heat pipe is connected to the recording material storage portion. By connecting the heat radiating portion of the loop-shaped meandering thin-tube heat pipe to a part of the recording material storage portion while maintaining the effect of claim 4 or 5, the generated excess heat is transmitted to the recording material. As a result, by increasing the temperature of the recording material such as transfer paper, it is possible to transfer and fix the toner image with more energy saving, and it is possible to obtain an effect that stable fixation becomes possible. . According to the seventh aspect of the present invention,
7. The heat fixing device according to claim 4, wherein the heating roller and the loop-shaped meandering thin-tube heat pipe are in contact with each other via a roller having a high thermal conductivity material and a low heat capacity.
By changing the length of inserting this roller, the recording material fixing area of the heating roller is adjusted, so the roller of high thermal conductivity material and low heat capacity material is replaced with the loop-shaped meandering thin tube heat pipe and heating roller. By inserting the heat roller between the loop-shaped meandering thin tube heat pipe and the heating roller by adjusting the length of the roller inserted, the effect that the heat conduction can be more easily controlled can be obtained.

According to the eighth aspect of the present invention, in the thermal fixing device according to the fourth, fifth, sixth or seventh aspect, the separated contact or contact area between the loop type meandering thin tube heat pipe and the heating roller portion is utilized. The controller is provided with a controller that controls the image forming conditions input from the operation unit by the user, so that the controller forms a loop based on the image forming conditions input from the entire touch panel of the operation unit by the user of the image forming apparatus. Since the separated contact or the contact area between the meandering thin tube heat pipe and the heating roller portion can be controlled, the effect that more appropriate operating conditions can be set can be obtained. Claim 9
According to the invention described in the above aspect, in the thermal fixing device according to any one of claims 4, 5, 6 and 7, the separated contact or contact area between the loop-shaped meandering thin tube heat pipe and the heating roller portion is provided in the bearing portion of the heating roller. The controller has a controller that controls the temperature based on the temperature detected by the temperature sensor. Therefore, the controller detects the loop type meandering thin tube heat pipe and the heating roller based on the temperature detected by the temperature sensor installed on the bearing of the heating roller. Since the separated contact or the contact area with the portion can be controlled, the effect that the service life of the heat fixing device can be further extended can be obtained.

According to the tenth aspect of the present invention, a latent image is formed on an image carrier, and the latent image is developed by toner of a developing unit to be visualized. An image forming apparatus for fixing an unfixed toner image carried on a recording material by using a heat fixing unit in a fixing unit after transferring the image to a recording material, wherein the fixing unit includes: Since it is configured to include the heat fixing device according to any one of the above, even when printing a narrow recording material continuously, using a loop type meandering thin tube heat pipe, the bearing at both ends of the heating roller of the fixing unit. Since it is possible to prevent a rise in the temperature of the unit and to make the temperature of the heating roller uniform, it is possible to realize an image forming apparatus that increases the reliability of the printing operation, prolongs the life of the unit, and can effectively use waste heat (energy). be able to.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus showing one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a heat fixing device showing one embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a heat fixing device showing another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a heat fixing device showing still another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a heat fixing device showing still another embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a main part of an image forming apparatus showing still another embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a heat fixing device showing still another embodiment of the present invention.

FIG. 8 is an explanatory diagram of a schematic configuration of a heat fixing device and a control system thereof according to still another embodiment of the present invention.

FIG. 9 is an explanatory diagram of a schematic configuration of a heat fixing device and a control system thereof according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal fixing device 2 Heating roller 3 Compression roller 4 Nip part 5 Harigen lamp 6 Planar processed loop-shaped meandering thin tube heat pipe 7 Ceramic material 8 Paper passage area 9 Loop-shaped meandering thin tube heat pipe 10a Heat absorption unit 10b Heat dissipation unit 11 Recording material Storage section 12 Small roller 13 Loop-type meandering thin tube heat pipe contact / separation mechanism 14 Controller 15 Temperature sensor 16 Operation panel 100 Image forming apparatus 101 Image carrier 102 Charging section 103 Optical system 104 Developing section 105 Toner 106 Recording material 107 Transfer section 108 Cleaning unit 109 Static elimination unit 110 Original

Claims (10)

[Claims] An image forming apparatus for forming a toner image on a recording material, wherein the fixing unit fixes the unfixed toner image carried on the recording material using heat fixing. A heat fixing device comprising: a heating roller; and a pressure roller facing and pressure-contacting the heating roller, and a loop-type meandering thin-tube heat pipe capable of changing a contact area is provided on the heating roller or the pressure roller. . 2. The heat fixing device according to claim 1, wherein a loop-shaped meandering thin tube heat pipe formed into a planar shape is provided on an inner surface of the heating roller. 3. The heat fixing device according to claim 1, wherein a loop-shaped meandering thin tube heat pipe formed into a planar shape is provided on an inner surface of the pressure roller. 4. The heat fixing device according to claim 1, further comprising a loop-shaped meandering thin tube heat pipe provided with a means capable of controlling the separation and contact of a part of the heating roller. Fixing device. 5. The heat fixing device according to claim 4, wherein a loop-shaped meandering thin tube heat pipe having a shape or a mechanism capable of controlling a contact area with the heating roller is provided. 6. The heat fixing device according to claim 4, wherein a heat radiation part of the loop-shaped meandering thin tube heat pipe is connected to a recording material storage part. 7. The heat fixing device according to claim 4, wherein the heating roller and the loop-shaped meandering thin tube heat pipe are in contact with each other via a roller having a high thermal conductivity material and a low heat capacity. A heat fixing device for adjusting a fixing area of a recording material of a heating roller by changing a length for inserting a recording medium. 8. The thermal fixing device according to claim 4, wherein an image of a separated contact or a contact area between the loop-shaped meandering thin tube heat pipe and the heating roller portion is input by a user from an operation unit. A heat fixing device, comprising: a controller that is controlled by setting forming conditions. 9. The heat fixing device according to claim 4, wherein a separation contact or a contact area between the loop type meandering thin tube heat pipe and the heating roller portion is provided in a bearing portion of the heating roller. A thermal fixing device, comprising: a controller that controls the temperature based on a temperature detected by a temperature sensor. 10. A latent image is formed on an image carrier, the latent image is developed by toner of a developing means to visualize the toner image, and the toner image on the image carrier is transferred to a recording material. An image forming apparatus for fixing an unfixed toner image carried on a recording material by using a heat fixing unit in a fixing unit, wherein the fixing unit includes a heat fixing unit according to any one of claims 1 to 9. An image forming apparatus comprising the apparatus.