JP3920733B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device and an image forming apparatus using the same, and more particularly to a heat exchange mechanism.
[0002]
[Prior art]
In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a printing machine, a fixing process is performed to prevent a developed toner image transferred from a photosensitive member forming a latent image carrier from peeling off from a transfer medium. Is executed.
In the fixing step, for example, an operation is adopted in which the toner used in the development processing is melted by heating and pressurizing, and the toner is infiltrated into a sheet or the like as an image carrier.
[0003]
One fixing method uses a belt wound around a plurality of rollers including a roller having a built-in heat source. This configuration has an advantage that the time required for starting up to a predetermined fixing temperature can be shortened by using a belt having a small heat capacity as compared with a configuration using a heat roller fixing system in which rollers are opposed to each other.
[0004]
In the belt fixing system, the above-described fixing process is performed when the belt heated by the heat source comes into contact with the toner. As a heat source system for heating the belt, the control and configuration are relatively simplified. An easy resistance heating method is often used.
[0005]
In the resistance heating method used as a heat source, the power consumption is extremely high, which is an undesirable configuration from the viewpoint of energy saving that has been increasingly demanded in recent years.
On the other hand, it is important in terms of preventing the occurrence of the offset phenomenon that the toner subjected to the fixing process is cooled and hardened as soon as it penetrates into the transfer medium in a state of being melted and softened by heating. From the viewpoint of energy saving, it is conceivable to reduce the fixing temperature by reducing the power consumption in the heat source.
In terms of the toner material in terms of lowering the fixing temperature, in this case, a toner whose softening point or melting point is inevitably low is selected, but the thermoplastic resin used in the toner is used. As a characteristic of the above, there is a property that the melt viscosity is inevitably lowered when the softening point or the melting point is lowered. This property is determined by the softening point or melting point of a thermoplastic resin depending on the molecular weight, molecular weight distribution, crystallinity, crosslinking degree, intermolecular force, etc. of the resin. The molecular weight and the degree of crosslinking must be lowered or the molecular weight distribution must be narrowed. Among these, since the lower limit of the molecular weight distribution is determined from the limit of the storage stability of the resin, lowering the molecular weight itself inevitably becomes narrower.
[0006]
Generally, when the molecular weight is lowered, the molecular chain is shortened, so that the entanglement is loosened and the melt viscosity is lowered. Further, even when the molecular weight distribution is narrowed, the entanglement of the molecular chains is loosened and the melt viscosity is lowered. Further, when the degree of cross-linking between molecules is lowered, each molecule is easy to move, so the melt viscosity is lowered. Therefore, if the fixing temperature is lowered, the toner characteristics Then Since the offset phenomenon is likely to occur, a configuration to eliminate the offset phenomenon has been proposed (for example, Japanese Patent Akira 51-29835). This publication discloses a configuration in which heat is applied to an object to be fixed in a fixing unit using a film sheet, and then the toner is solidified and then peeled off after the film sheet and the object to be fixed are kept in close contact with each other. In order to further accelerate the cooling effect of the toner Forced A configuration for cooling is disclosed. As a method for promoting the latter toner cooling effect, there are configurations described in Japanese Patent Application Laid-Open Nos. 5-273766 and 2001-22198.
[0007]
In Japanese Patent Application Laid-Open Nos. 5-273766 and 2001-22198, a cooling means is provided at a corresponding position after passing through the fixing nip portion in the extension region of the belt, or the fixing nip portion in the moving direction of the belt. A configuration is disclosed in which a roller around which the belt that has passed is used as a cooling means.
[0008]
[Problems to be solved by the invention]
When forced cooling by air blowing is used, the surrounding air is cooled by flowing the surrounding air at the time of air blowing, or a device that dislikes temperature rise due to the diffusion of hot air by air blowing, for example, melting due to heat has occurred. Later, coagulation occurs, which adversely affects a device containing toner that is likely to cause blocking. In addition, when water or other liquid is used as the heat medium instead of air blowing, the equipment including the circulation path becomes large, which may increase the size of the apparatus.
[0009]
As a configuration for suppressing the heat generated in the fixing device from affecting the peripheral portion, there is a configuration in which the fixing device is thermally blocked from the peripheral portion instead of cooling a member used in the fixing device. Specifically, a heat shield wall is provided that surrounds the entire range or a part of the fixing device excluding the fixing nip portion. In this configuration, it is possible to suppress the radiation heat or convection heat from the fixing device. However, even when such a configuration is adopted, if the temperature rises due to the heat storage of the heat shield wall itself, the ambient temperature of the peripheral portion increases, and as a result, as in the case of the cooling configuration described above, The temperature rises, and the toner blocking phenomenon tends to occur.
[0010]
As described above, in the cooling or heat shielding structure in the fixing device, the main purpose is to prevent the dissipation of the generated heat, and energy consumption efficiency is improved by leaving a part of the generated heat unused. It will get worse and it will be difficult to achieve energy savings.
[0011]
As a configuration that effectively uses the heat generated in the fixing device, if the belt fixing method is targeted, the heat of the stretched portion heated by the heat source is transferred to the stretched portion of the reheating region that has passed through the cooling unit, A so-called configuration for performing heat exchange has been proposed (for example, JP-A-2001-22198).
[0012]
In the above publication, heat exchangers that are in contact with both sides of the belt extension part are provided, the extension part that has passed through the fixing nip after heating is absorbed by cooling, and the heat is opposed to the extension part and the heat source. It is transmitted to the previous extension part. In addition, a configuration is disclosed in which a Peltier element capable of switching between heating and cooling by supplying electric power is used as a heat exchanger so that temperature changes are efficiently performed at each extended portion on the cooling side and the heating side.
[0013]
However, this configuration has the following problems.
Since the Peltier element used to efficiently change the temperature at each stretched part requires an external power supply, a power supply dedicated to this element is required, and as a result, it is used for the fixing device. In addition to the heat source to be used, the power consumption part is added, which is contrary to energy saving.
The Peltier element is formed in an ingot shape or a disk shape having a sandwich structure with ceramics provided on a surface layer portion, and has a structure made rigid by ceramics. For this reason, it may be damaged if bent. For this reason, as shown in the above publication, the Peltier element is disposed so as to contact a flat surface of another belt having a surface that contacts the fixing belt, or disposed so as to contact the flat extending surface of the fixing belt. Will be adopted.
[0014]
When a Peltier element is used, heat can be exchanged for the belt by being able to perform auxiliary heating and cooling, but the belt used in the fixing device is matched to the structure of the Peltier element as described in the above publication. In addition, there is a case where a flat surface is formed, and there is a case where the surface has a curved surface. In such a case, there is a possibility that a heat exchanger that can perform auxiliary heating and cooling cannot be used. In addition, in the above publication, one of the rollers around which the belt is wound is provided as a heating member having a heat source, and the other of the rollers is provided as a cooling member. As a result, there is a risk of complication of the configuration.
[0015]
Further, in the Peltier element, the thermal conductivity of the ceramic located in the surface layer portion is poor, and a sudden temperature change cannot be expected. For this reason, in order to select a steep temperature change, it is necessary to increase the power. As a result, the power consumption tends to increase, and there is a possibility that energy saving cannot be achieved.
[0016]
An object of the present invention is to provide a structure that can ensure energy saving with a simple configuration regardless of the surface form of the fixing member, in view of the problems in the above-described conventional fixing apparatus, in particular, the fixing apparatus when the surface form of the fixing member is not a flat surface. A fixing device and an image forming apparatus.
[0017]
[Means for Solving the Problems]
The invention described in claim 1 The fixing member heated by the heat source and the pressure member in contact with the fixing member constitute a fixing nip portion, and the heat source is incorporated in the fixing member constituting the fixing nip portion. Recording material carrying an unfixed toner image Pass through In the fixing device, A heat recovery member is provided at a position where the remaining heat after fixing can be recovered at a position where the recording material has passed through the fixing nip portion, and a heat supply member is provided at a position different from the fixing nip portion. The member and the heat supply member are integrated, and the heat recovery member has both a cooling and heating action through electric power supply by a thermoelectric effect, and a frigister element that can be deformed in accordance with the form of the fixing nip portion. And that the heat supply member is located on one side of the transistor element. It is a feature.
[0018]
The invention according to claim 2 As the fixing member, a belt wound around a rotatable roller incorporating the heat source is used, and as the pressure member, the belt is wound around a roller facing the rotatable roller incorporating the heat source. A belt that presses the recording material against a belt as a fixing member is used, and the heat recovery member is provided in contact with the opposing position of the rollers at a position where the sheet passes, and the heat recovery member The integrated heat supply member is provided in contact with a position where the belt moves toward a position where the rollers face each other. It is a feature.
[0019]
The invention according to claim 3 As the fixing member, a fixing roller having a built-in heat source is used, and as the pressure member, a pressure roller capable of forming a fixing nip portion in contact with the fixing roller is formed, and the fixing nip portion of the fixing roller is used. A heat recovery member is disposed at a position excluding the heat transfer member, a heat supply member is disposed at a position passing through the fixing nip portion in the circumferential direction of the fixing roller, and a member capable of utilizing a thermoelectric effect is used as the heat recovery member. The heat recovery member and the heat supply member are electrically connected to a voltage stabilization device, and the voltage stabilization device utilizes the electromotive force generated by the thermoelectric effect in the heat recovery member. The surface temperature of the roller As described above, the temperature of the heat supply member is controlled.
[0020]
The invention according to claim 4 The fixing device according to claim 1 is used in an image forming apparatus. It is characterized by that.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus to which a fixing device according to an embodiment of the present invention is applied.
The image forming apparatus shown in FIG. 1 also has a copying function capable of forming an electrostatic latent image on a photoconductor as a latent image carrier based on image information obtained by reading a document and image information from a host computer. It is a full-color printer that can perform visible image processing of an electrostatic latent image using a plurality of colors.
[0038]
In FIG. 1, a photoconductor 2 that is a drum-shaped latent image carrier is disposed inside an image forming apparatus 1.
A charging device 3, a writing device 4, a developing device 5, a transfer device 6, and a cleaning device 7 that perform image forming processing along the rotation direction of the photosensitive member 2 are disposed around the photosensitive member 2.
[0039]
The writing device 4 used in the image forming apparatus 1 in this embodiment is provided with a laser light source that can emit laser light in accordance with an image signal from a control unit (not shown). However, the writing light is emitted not only by the output signal from the computer but also by the image signal based on the original image read by the scanner 8 provided in the image forming apparatus 1. That is, the image forming apparatus 1 is provided with a document placing table 1A on the upper surface of the housing so that a document can be placed. Below the document placing table 1A, a scanner 8 for reading a document image is provided. Is provided.
The scanner 8 includes a reading optical system having a known structure and a reading element, and image information obtained by the reading element is output to the control unit.
[0040]
The writing device 4 is not provided with a reference numeral, but includes a polygon mirror 4A, an fθ lens 4B, a BTL lens 4C, and a writing mirror 4D in addition to a laser light source (not shown). The scanner 8 includes a scanning light source and a reflecting mirror. A first scanner unit 8A movable in parallel with the document table, a second scanner unit 8B movable with a pair of mirrors for optical path conversion, a lens 8C, and a CD element as an optical reading element. The provided board 8D is equipped.
[0041]
The transfer device 6 in this embodiment includes a primary transfer device 6A that primarily transfers a visible image from the photoreceptor 2, and a secondary transfer that performs secondary transfer from the primary transfer device 6A to a sheet such as a recording sheet. The apparatus 6B is equipped.
The primary transfer device 6A includes an intermediate transfer belt 6A1 wound around a plurality of rollers. The primary transfer device 6A is mounted on the photoreceptor 2 by a primary transfer charger 6A2 disposed at a position opposite to the intermediate transfer belt 6A1 and the photoreceptor 2. These visible images can be transferred to the intermediate transfer belt 6A1.
On the intermediate transfer belt 6A1, an image of a color complementary to the color separation can be superimposed and transferred by a developing device 5 described later, and the superimposed transfer image is recorded on a recording sheet or the like by a secondary transfer device 6B. The sheet is transferred onto a sheet (hereinafter referred to as a sheet).
[0042]
The secondary transfer device 6B is composed of a charging roller that can be brought into contact with and separated from the intermediate transfer belt 6A1 in the primary transfer device 6A across the sheet conveyance path, and performs intermediate transfer while nipping and conveying the moving sheet. The superimposed image on the belt 6A1 can be electrostatically transferred to the sheet.
The secondary charging device 6B can be brought into contact with the intermediate transfer belt 6A1 only at the time of transferring a single color and at the time of batch transfer of superimposed images, and when the images of the respective colors are transferred to the intermediate transfer belt 6A1, the intermediate transfer belt. The image is not disturbed without coming into contact with 6A1.
[0043]
A sheet is fed by a sheet feeding device 9 to a secondary transfer position corresponding to a position where the intermediate transfer belt 6A1 and the secondary transfer device 6B face each other.
The paper feeding device 9 includes a paper feeding cassette 9A that can store recording paper, a feeding roller 9B that feeds out the sheets in the paper feeding cassette 9A, a separation roller pair 9C, a conveying roller 9D, and a registration roller 9E. A sheet separated from the sheet feeding cassette 9A toward the next transfer position is fed with registration timing set by a registration roller 9E.
[0044]
In this embodiment, it is also possible to feed sheets other than the sheet size from the inside of the sheet feeding cassette or different types of sheets. Therefore, a manual feed tray 9F, a part of which can be tilted, is provided in the casing of the main body of the image forming apparatus, and the sheet fed from the paper feed tray 9A is moved between the manual feed tray 9F and the registration roller 9E. A conveying roller 9D is disposed at a position where the paths meet, and a feeding roller 9B is disposed in the vicinity of the manual feed tray 9F.
[0045]
In the above configuration, the electrostatic latent image formed on the photoreceptor 2 is subjected to visible image processing by the developing device 5 and transferred to the intermediate transfer belt 6A1 by the primary transfer device 6A.
When the image is a single color, the transferred image on the intermediate transfer belt 6A1 is secondarily transferred as it is to the sheet fed from the paper feeding device 9 by the secondary transfer device 6B, and when the image is a plurality of colors, the intermediate transfer is performed. After the superimposed transfer onto the belt 6A1, the sheet is collectively transferred to the sheet by the secondary transfer device 6B.
The sheet after the secondary transfer is separated from the secondary transfer position, conveyed to the fixing device 11 via the conveying device 10, and the image is fixed and discharged.
[0046]
Less than, Of the present invention Embodiment about explain.
FIG. 2 is a diagram for explaining the principle configuration of the fixing device according to the embodiment of the present invention. The fixing device 11 shown in FIG. 2 is a toner carried on the sheet S while nipping and conveying the sheet S. First and second fixing members 11A and 11B that face each other at a fixing position corresponding to a fixing nip portion that can heat and press T are provided, and a belt (hereinafter, referred to as a fixing belt 11A) is used on one of them. ing.
As the other fixing member, a pressure belt 11B that presses a sheet against the fixing belt 11A is used, and the fixing device 11 adopts a belt fixing method.
The fixing belt 11A is wound around a pair of rollers 12 and 13, and one of the extending portions formed between these rollers moves in the same direction while coming into contact with the pressure belt 11B.
The fixing belt 11A is maintained at a fixing temperature by being heated by a heat source 12A using a resistance heating system built in one of the rollers 12 around which the belt is wound.
The heat source 12A is feedback-controlled by a temperature sensor (not shown) that detects the surface temperature of the fixing belt.
[0047]
In the fixing belt 11A, a heat recovery member 13 that is in contact with the inner surface in the region of the fixing nip portion is disposed.
The heat recovery member 13 is brought into contact with the fixing belt 11A at a position where the residual heat after fixing can be recovered in the fixing nip portion, and the fixing on the surface opposite to the contact surface is on the side opposite to the fixing nip portion side. It is integrated with the heat supply member 14 that contacts the extended surface of the belt 11A.
[0048]
The heat supply member 14 is made of a noble metal such as gold, silver and copper, or a good heat conductor such as aluminum. The heat supply member 14 is on the side in contact with the expansion surface of the fixing belt 11 </ b> A that is opposite to the surface integrated with the heat recovery member. The surface is positioned at a position before reheating by the heat source 12A.
[0049]
As the heat recovery member 13, a member that can obtain both the cooling by heat absorption and the heating by heat generation on the front and back surfaces by power supply, which is one of the thermoelectric effects, is used. In the configuration shown in FIG. It has been.
[0050]
The transistor elements 13A are configured to be in contact with the surface form of the fixing belt 11A. As shown in FIG. 3, the arrangement interval between adjacent elements within a predetermined area is set to about 0.01 to 5 mm. In either case, a sheet-like structure is used by repeatedly folding back and spreading continuously, or a sandwich structure with a thin film on both sides is used. Thus, it can be bent and deformed.
[0051]
The surface of the heat recovery member 13 that comes into contact with the fixing belt 11A by energizing the transistor element 13A functions as a cooling surface, and the opposite surface functions as a heat generation surface. For this reason, the heat supply member 14 integrated on the opposite side is heated and the fixing belt 11A is preheated by the heat source 12A before being reheated.
[0052]
In the present embodiment, the heat recovery member 13 can be brought into contact with the surface form of the fixing belt 11A with the above-described configuration, so that a part of the fixing belt 11A has a curved surface as shown in FIG. Even if it exists, it can be bent and deform | transformed corresponding to the surface form. Accordingly, since the contact can be made uniformly regardless of the surface form of the fixing belt 11A, heat absorption from the fixing belt 11A, that is, cooling unevenness can be eliminated, and the cooling effect of the fixing belt 11A can be enhanced.
[0053]
The configuration shown in FIG. 4 is a configuration that follows the principle configuration shown in FIG. 2, and in this configuration, the fixing belt 1A is wound around only the roller 12 including the heat source 12A, not a pair of rollers. The end in the extending direction is guided with respect to the support member 11A1 that can guide the fixing belt 11A instead of the roller 13 shown in FIG.
The support member 11A1 has a curved surface that can press the fixing belt 11A toward the pressure belt 11B. The curved surface enlarges the fixing nip portion and uniformizes the contact pressure with the toner T, thereby preventing uneven fixing due to uneven heating. It is designed to prevent the occurrence. Therefore, the heat recovery member 13 is formed in contact with the curved surface of the fixing belt 11A.
[0054]
On the other hand, the energization of the transistor element 13A generates heat on the surface opposite to the cooling surface, the heat is transmitted to the heat supply member 14, and the fixing belt 11A in contact with the heat supply member 14 is spared before reheating. It will be heated. Accordingly, the cooling of the fixing belt 11A is promoted to promote the cooling and hardening of the toner to be fixed, while the power consumption in the heat source 12A can be suppressed by the preliminary heating of the fixing belt 11A.
[0055]
As shown in FIG. 5, the transistor elements 13 </ b> A used for the heat recovery member 13 have a plurality of transistor elements 13 </ b> A as shown in FIG. Can also be juxtaposed. Also in this case, similarly to the above-described configuration, the arrangement interval between adjacent ones is set to 0.01 to 5 mm. This interval is set in order to eliminate temperature unevenness within a predetermined area.
[0056]
The energization control to the transistor element 13 shown in FIGS. 2 and 5, that is, the on / off setting, is performed based on the temperature on the cooled surface side or the heat generating surface side of the fixing belt 11A. That is, for the on / off setting, the thermocouple 13B whose operation state is switched at a predetermined temperature is used.
[0057]
The energization control of the transistor elements 13A targeted for the configuration shown in FIG. 5 can be performed for each of the transistor elements 13A, whereby fine temperature management corresponding to the surface temperature of the fixing belt 11A can be performed. In other words, when the surface temperature of the fixing belt 11A is higher than the predetermined temperature, the energization to any of the transistor elements 13A is stopped.
As a result, the temperature management of the fixing belt 11A by the transistor element 13A is automated. In this way, heat is circulated by using the heat radiation by cooling to heat the fixing belt 11A.
[0058]
In the above-described embodiment, the fuser element 13 is configured to be able to uniformly contact the fixing belt 11A as a fixing member in accordance with the surface form of the fixing belt 11A by bending and deforming, so that the fixing belt 11A is heated. It can be pressed by the recovery member 13. As a result, the contact pressure of the fixing belt 11A with the sheet S is increased, the contact with the toner T can be improved, and the heat supply efficiency with respect to the toner T can be increased. In addition, since the contact state between the fixing belt 11A after fixing and the heat recovery member 13 is also improved, the recovery efficiency of the residual heat is enhanced, the toner cooling effect is promoted, and the molten toner is reversely transferred to the transfer belt 11A. Can be surely prevented.
[0059]
next, In the present invention Of the fixing device another Embodiments will be described.
The present embodiment is characterized in that an electromotive force is generated corresponding to the heat recovered by the heat recovery member, and the fixing member is preheated by the heat supply member using this electromotive force.
In the fixing device 20 shown in FIG. 6, the first fixing member is composed of a fixing roller 21 including a heat source 21 </ b> A, and the second fixing member is in contact with the fixing roller 21 so as to form a fixing nip portion. A roller 22 is used.
[0060]
Unlike the configuration shown in FIG. 2, the heat recovery member 23 is disposed in the vicinity of the outer periphery of the fixing roller 21, and is disposed in a range including at least the upper portion of the fixing roller 21. In the configuration shown in FIG. 6, it is arranged in three directions excluding the fixing nip portion that faces and contacts the pressure roller 22. Thereby, the heat dissipated from the fixing roller 21 can be efficiently absorbed.
[0061]
As the heat recovery member 23, a member that can use the Seebeck effect or the Peltier effect, which is a thermoelectric effect that generates an electromotive force due to a temperature difference based on the amount of recovered heat, is used. In the configuration shown in FIG. 6, a thermocouple or a Peltier element is used. .
When a thermocouple or Peltier element is used as the heat recovery member 23, particularly when a Peltier element is used, the material from the fixing roller 21 as shown in FIG. It is also possible to dispose only above the fixing roller 21 corresponding to a position where heat is easily absorbed.
[0062]
Since the heat recovery member 23 has a thermoelectric effect, the heat recovery member 23 is used as a flexible member that can be flexibly deformed into a shape following the outer peripheral surface of the fixing roller 21 as shown in FIG. It is also possible to employ a possible transistor element (denoted by reference numeral 23 'for convenience). In this case, the configuration shown in FIG. 3 or FIG.
[0063]
The heat recovery members 23 and 23 ′ are connected to the input side of the voltage stabilization device 24, and the heat supply member 25 that is in contact with the peripheral surface of the fixing roller 21 is connected to the output side of the voltage stabilization device 24. ing.
The voltage stabilizing device 24 is a device for managing the temperature of the heat supply member 25, and can control the applied voltage including on / off control to the heat supply member 25 so that the surface temperature of the fixing roller 21 reaches a predetermined temperature. It is like that. In addition, the arrow shown with a broken line in FIG. 8 has shown the signal path | route of the feedback signal for performing the temperature management of the heat supply member 25. FIG.
[0064]
The heat supply member 25 is composed of a roller member capable of generating heat by the electric power applied from the voltage stabilizing device 24. In this configuration, a resistance heating element or a lamp is used. However, the structure is flexible and flexibly deformed. It is also possible to attach a frigister element, which is a thermoelectric element that can be used, to the roller peripheral surface.
[0065]
In this embodiment, in the configuration as described above, when the heat dissipated from the fixing roller 21 is absorbed by the heat recovery member 23, the electromotive force is generated due to the temperature difference between the fixing roller 21 side and the opposite side of the heat recovery member 23. The generated electromotive force is taken into the voltage stabilizing device 24.
[0066]
In the voltage stabilizing device 24, the voltage applied to the heat supply member 25 is controlled in accordance with the surface temperature of the fixing roller 21, and the preheating of the fixing roller 21 using the heat supply member 25 is executed. As a result, the fixing roller 21 maintains the surface temperature at a predetermined temperature by heating from the heat supply member 25 serving as a heat source other than the heat source 21A, so that power consumption at the heat source 21A can be reduced. Thus, by converting the exhaust heat remaining in the fixing roller 21 into heat energy for heating the fixing roller 21, it is possible to reduce the load on the heat source 21A and save energy.
[0067]
The inventor compared the power consumption of the above configuration with the internal configuration, and as a result, the configuration shown in FIG. 6 can confirm about 10% energy saving, and the configuration shown in FIG. In the configuration shown in FIG. 8, although the loss of about 10 to 15 percent occurs due to the narrow arrangement area of the heat recovery members 23 and 23 ′, the load reduction at the heat source 21 </ b> A is obvious. Energy saving was confirmed compared with the case of not using.
[0068]
In order to efficiently and particularly extract a large amount of electromotive force generated in the heat recovery members 23 and 23 ′, it is necessary to increase the temperature difference between the heat recovery members 23 and 23 ′. Hereinafter, an embodiment of the invention described in claim 19 will be described with respect to this configuration.
In FIG. 9, a heat radiating fin 26 is provided as a forced cooling means for increasing the temperature difference between the surface facing the fixing roller 21 and the surface opposite to the heat recovery member 23 shown in FIG. 7. The structure which contacts the airflow F with the ventilation means which is not shown in figure with respect to the fin 26 is shown. As a result, the heat radiation area can be expanded, and the temperature difference between the heat absorbing surface in contact with the fixing roller 21 and the decaying surface on the opposite side can be expanded.
[0069]
FIG. 10 shows a configuration in which a heat exchanger 27 capable of circulating a heat medium as a forced cooling means is provided on the surface opposite to the side facing the fixing roller 23 for the heat recovery member 23 having the configuration shown in FIG. It is shown. In this configuration, water or oil is used as a heat medium, heat exchange is performed by a heat medium circulating through a cooling unit (not shown), and the temperature difference between the heat absorption surface and the heat radiation surface of the heat recovery member 23 is increased. be able to.
[0070]
The inventor conducted an experiment on the energy saving effect of the configuration shown in FIGS. 9 and 10. The configuration shown in FIG. 9 increased the energy conversion efficiency by about 20% or more compared to the configuration shown in FIG. 7. In the configuration shown in FIG. 10, energy saving of 20% or more was confirmed in the same manner as described above in the configuration shown in FIG. Moreover, it was confirmed that the temperature at the periphery of the fixing device could be stopped within 40 ° C. By adopting such a configuration, it is possible to recycle the heat by the recovered heat, thereby suppressing the increase in the load on the heat source and realizing energy saving, speeding up the temperature rise at the fixing member, and further, inside the apparatus. Therefore, it is possible to prevent thermal adverse effects on the devices arranged around the fixing device.
[0071]
In particular, when a transistor element 23 ′ provided in a shape following the outer peripheral surface of the fixing rotor 21 is used, the peripheral surface of the fixing roller 21 is compared with a case where an ingot-shaped or disk-shaped member having a normal structure is used. Therefore, it has been confirmed that the energy can be further reduced by about 10% as compared with the configuration shown in FIGS. Thereby, energy saving efficiency is improved regardless of the form or shape of the fixing member.
[0072]
【The invention's effect】
Claim 1 to 3 According to the invention described, 3. A fixing member that generates heat on a surface opposite to the cooling surface by energization of a transistor element used for a heat recovery member, and that heat is transmitted to the heat supply member and is in contact with the heat supply member. In the present invention, the fixing belt, and in the third aspect of the present invention, the fixing roller is preheated before reheating. Accordingly, the cooling of the fixing member is promoted to promote the cooling and hardening of the toner to be fixed, while the preheating of the fixing belt 11A can suppress the power consumption at the heat source. .
[0073]
Claim 4 According to the described invention, Residual heat generated in the fixing member having a heat source can be recovered and the fixing member before reheating can be heated, and an electromotive force generated corresponding to the recovered heat is used during the heating, The heat accumulated in the fixing member can be circulated, thereby reducing the load on the existing heat source and enabling energy saving. .
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of an image forming apparatus to which a fixing device according to an embodiment of the present invention is applied.
FIG. 2 is a schematic diagram for explaining a principle configuration of a fixing device according to an embodiment of the present invention.
FIG. 3 is a view for explaining the configuration of a heat recovery member used in the fixing device shown in FIG. 2;
4 is a diagram for explaining an operation in the principle structure shown in FIG. 2; FIG.
FIG. 5 is a diagram for explaining another configuration of the heat recovery member shown in FIG. 2;
FIG. 6 is a diagram illustrating another configuration of the fixing device according to the embodiment of the invention.
7 is a diagram showing a partial modification of the configuration shown in FIG. 6. FIG.
8 is a diagram showing still another modification of the configuration shown in FIG.
FIG. 9 is a diagram illustrating another configuration of the fixing device according to the embodiment of the invention.
10 is a diagram showing a partial modification of the configuration shown in FIG. 9;
[Explanation of symbols]
1 Image forming device
11 Fixing device
11A First fixing member
11B Second fixing member
12A heat source
13, 23, 23 'heat recovery member
13A Frigister element
14,25 Heat supply member
24 Voltage stabilizer
26 Radiation fins as forced cooling means
27 Heat exchanger as forced cooling means

Claims (4)

The fixing member heated by the heat source and the pressure member in contact with the fixing member constitute a fixing nip portion, and the heat source is incorporated in the fixing member constituting the fixing nip portion and carries an unfixed toner image. In the fixing device that passes the recorded material,
A heat recovery member is provided at a position where the residual heat after fixing is recovered at a position where the recording material has passed through the fixing nip portion, and a heat supply member is provided at a position different from the fixing nip portion,
The heat recovery member and the heat supply member are integrated, and the heat recovery member can have both cooling and heating effects through power supply by the thermoelectric effect, and can be deformed following the form of the fixing nip portion. A fixing device using a frigister element, wherein the heat supply member is located on one surface of the fristister element . As the fixing member, a belt wound around a rotatable roller incorporating the heat source is used, and as the pressure member, the belt is wound around a roller facing the rotatable roller incorporating the heat source. A belt that presses the recording material against a belt as a fixing member is used,
The heat recovery member is provided in contact with the opposing position of the rollers at the position where the sheet passes, and the heat supply member integrated with the heat recovery member is directed toward the opposing position of the rollers. The fixing device according to claim 1, wherein the fixing device is provided in contact with a position where the belt moves . As upper Symbol fixing member, the fixing roller with a built-in heat source is used in contact opposite to the fixing roller person as the pressure member, the fixing nip portion is capable of forming a pressure roller is used,
A heat recovery member is disposed at a position excluding the fixing nip portion of the fixing roller, and a heat supply member is disposed at a position passing through the fixing nip portion in the circumferential direction of the fixing roller.
A member that can use a thermoelectric effect is used as the heat recovery member, and the heat recovery member and the heat supply member are electrically connected to a voltage stabilizing device,
The voltage stabilizing device performs temperature management of the heat supply member so that the surface temperature of the fixing roller becomes a predetermined temperature using an electromotive force generated by a thermoelectric effect in the heat recovery member. The fixing device according to claim 1. An image forming apparatus using the fixing device according to claim 1.

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