JP5481404B2 - Fixing apparatus and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a fixing device and an image forming apparatus such as a copying machine and a printer provided with the fixing device, and more particularly to improvement of heat insulation of the fixing device.

  In a conventional image forming apparatus, a predetermined electrostatic latent image in which charging is partially attenuated by irradiating a laser beam from an exposure unit onto an image carrier such as a photosensitive drum uniformly charged by a charging unit. After an image is formed and toner is attached to the electrostatic latent image by a developing unit to form a toner image, the toner image is transferred onto a recording medium using a transfer unit, and unfixed toner is heated and pressurized by a fixing device. Then, an image forming process for making a permanent image is executed.

  In the fixing device as described above, the amount of heat that does not contribute to the fixing operation is also radiated to the outside of the fixing device, so that unnecessary heat is applied to the photosensitive member and the cleaning unit arranged around. As a result, the driving torque of the apparatus increases due to the solidification of the toner, and in the worst case, the apparatus may stop, or the density abnormality may occur due to uneven charging on the surface of the photoreceptor. In addition, since the temperature inside the apparatus rises due to heat radiation from the fixing device, it also adversely affects other systems inside the apparatus, causing problems such as a reduction in image quality and durability of members.

  Conventionally, measures have been taken such as suppressing the temperature rise by providing an air flow between the fixing device and another system. However, cooling the fixing device leads to an increase in the amount of heat generated to ensure the amount of heat necessary for the fixing operation, and thus wasteful energy consumption increases, and there is a problem from the viewpoint of energy saving.

  Therefore, a method for suppressing heat radiation from the fixing device without using a cooling means such as a fan has been proposed. For example, Patent Document 1 discloses a porous roller on the inner wall surface of a housing in a heat roller type fixing device. There is disclosed a technique for ensuring heat insulation by attaching a ceramic heat insulating material, and collecting and reusing the heat insulating material from a used fixing device.

  Patent Document 2 discloses a configuration in which a guide member is provided on the outer or inner surface of the fixing device, and the heat insulating member can be attached and detached together with the guide member. Furthermore, Patent Document 3 discloses that a fixing device frame is formed by gas injection molding or blow molding, and has a gas layer that is substantially sealed inside the frame. A fixing device with improved efficiency is disclosed.

Japanese Patent Laid-Open No. 2005-77996 JP 2004-333734 A JP 2004-233548 A

  Incidentally, the heat insulation required for the housing of the fixing device varies depending on the specifications of the image forming apparatus on which the fixing device is mounted. For this reason, when one fixing device is mounted on a plurality of types of image forming apparatuses, it is necessary to adjust the heat insulation. However, it is difficult to adjust the heat insulation with the fixing devices disclosed in Patent Documents 1 to 3.

  Further, in order to stabilize the fixing of the toner image in the fixing device, it is necessary to make the temperature distribution of the fixing roller pair uniform in the axial direction. However, when the paper passes through the pair of fixing rollers, the heat of the portion where the paper contacts (paper passing area) is taken away by the paper, so that the heat is not taken away by the paper in the portion where the paper does not pass (non-paper passing area). The heat will be stored for that amount.

  For this reason, when printing on a small size paper is continuously performed, the temperature of the non-sheet passing area rises more than necessary, and there is a problem that the life of the fixing roller pair is shortened. On the other hand, if the overall temperature is lowered in accordance with the temperature rise in the non-sheet passing area, the temperature in the sheet passing area is also lowered, so that the amount of heat necessary for fixing cannot be supplied to the sheet.

  In the fixing devices disclosed in Patent Documents 1 to 3, the temperature rise in the non-sheet passing region that occurs during continuous printing of a small size as described above is not taken into consideration. In view of the demand for further downsizing, cost reduction, and energy saving of the image forming apparatus, development of a low-cost and compact fixing device has been demanded.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a fixing device that can suppress energy loss due to heat radiation to the outside of the fixing device as much as possible with a simple configuration and can easily adjust the heat insulation property, and an image forming apparatus including the fixing device. For the purpose.

  In order to achieve the above object, the present invention provides a fixing member comprising a heating member incorporating a heating means, a pressure member pressed against the heating member at a predetermined pressure, and a recording medium containing the fixing member and storing the fixing member A housing in which openings are formed on the upstream side and the downstream side in the transport direction, and a heat shield plate that is disposed in a portion of the inner surface of the housing facing the heating member and reflects heat radiation from the heating member. In the fixing device, a heat insulating layer formed by laminating a plurality of sheet-like heat insulating materials in which a plurality of thin tubes are arranged in parallel on at least one surface is formed between the inner surface of the housing and the heat shield plate. Yes.

  According to the present invention, in the fixing device configured as described above, the heat insulating material is laminated so that a direction of the thin tube and an axial direction of the heating member coincide with each other.

  According to the present invention, in the fixing device configured as described above, at least a part of the heat insulating material is laminated so that a direction of the thin tube is orthogonal to an axial direction of the heating member.

  According to the present invention, in the fixing device having the above-described configuration, the heat insulating material is arranged so that the direction of the narrow tube is in the region facing the sheet passing region of the heating member and the region facing the non-sheet passing region of the heating member. The ratio of the said heat insulating material orthogonal to the axial direction of a member differs.

  According to the present invention, in the fixing device having the above-described configuration, the region of the heating member facing the sheet passing region is smaller than the region facing the non-sheet passing region of the heating member. It is characterized by being stacked in large numbers.

  According to the present invention, in the fixing device having the above-described configuration, the region facing the paper passing region of the heating member is the same heat insulating material as the heat insulating material stacked in a region facing the non-paper passing region of the heating member. It is characterized in that a large number of sheets are stacked by compressing.

  According to the present invention, in the fixing device configured as described above, the heat shield plate and the heat insulating layer are also provided in a portion of the inner surface of the housing facing the pressure member.

  The present invention is also an image forming apparatus including the fixing device having the above-described configuration.

  According to the first configuration of the present invention, a plurality of sheet-like heat insulating materials in which a plurality of thin tubes are arranged in parallel on at least one surface are laminated on the inner surface of the housing to form a heat insulating layer, whereby the thin tubes are air in the heat insulating layer. Insulation can be improved to regulate convection. Moreover, the heat insulation of a heat insulation layer can be easily adjusted by changing the internal diameter of the thin tube of the heat insulating material to laminate | stack.

  Further, according to the second configuration of the present invention, in the fixing device having the first configuration, the heat insulating material is laminated so that the direction of the thin tube and the axial direction of the heating member coincide with each other to form the heat insulating layer. Thus, since air can freely move in the narrow tube in the axial direction of the heating member, variation in temperature distribution in the axial direction of the heating member can be reduced.

  Further, according to the third configuration of the present invention, in the fixing device of the first configuration, at least a part of the heat insulating material is laminated so that the direction of the thin tube is orthogonal to the axial direction of the heating member. Since the convection of air in the axial direction of the heating member is hindered as compared with the case where the thin tubes are aligned with the axial direction of the heating member, the heat insulating property of the heat insulating layer becomes higher.

  According to the fourth configuration of the present invention, in the fixing device according to the third configuration, the direction of the narrow tube in the region facing the sheet passing region of the heating member and the region facing the non-sheet passing region of the heating member. However, by changing the ratio of the heat insulating material orthogonal to the axial direction of the heating member, the heat insulating property of the region facing the non-paper passing region and the region facing the paper passing region can be varied separately. Therefore, the heat insulating property of the heat insulating layer can be adjusted more easily.

  According to the fifth configuration of the present invention, in the fixing device having any one of the first to fourth configurations, the region facing the sheet passing region of the heating member faces the non-sheet passing region of the heating member. By laminating a large number of heat insulating materials whose inner diameters of the narrow tubes are smaller than those of the areas to be used, by restricting the air convection by the small diameter thin tubes in the area facing the paper passing area, heat insulation is improved and heat loss is lost. Can be suppressed. On the other hand, in the region facing the non-sheet passing region, the excessive temperature rise at both ends of the heating member can be suppressed by enlarging the space in which air is convected by the large-diameter thin tube to promote heat dissipation.

  According to the sixth configuration of the present invention, in the fixing device having any one of the first to fourth configurations, the region facing the sheet passing region of the heating member faces the non-sheet passing region of the heating member. By compressing the same heat insulating material as the heat insulating material stacked in the area to be laminated and laminating a large number of sheets, the area facing the paper passing area is compressed and crushed to restrict air convection, thereby insulating the air. The loss of heat quantity can be suppressed by improving the property. On the other hand, in a region facing the non-sheet passing region, a space in which air is convected is enlarged by a thin tube that is not compressed to promote heat dissipation, thereby suppressing an excessive temperature rise at both ends of the heating member. Moreover, since the same heat insulating material can be used in the region facing the paper passing region and the region facing the non-paper passing region of the heating member, the number of members can be reduced.

  According to the seventh configuration of the present invention, in the fixing device having any one of the first to sixth configurations, the heat shield plate and the heat insulating layer are also provided on a portion of the housing inner surface facing the pressure member. As a result, energy loss due to heat radiation from the fixing member can be more effectively suppressed.

  Further, according to the eighth configuration of the present invention, by mounting the fixing device having any one of the first to seventh configurations, energy loss due to heat radiation to the outside of the fixing device can be suppressed as much as possible. Therefore, the image forming apparatus can be easily adjusted.

1 is a side sectional view showing the internal structure of an image forming apparatus equipped with a fixing device according to the present invention. 1 is a side sectional view of a fixing device according to an embodiment of the present invention. Perspective view of the upper housing of the fixing device as seen from the inside A plan view showing an example of a heat insulating material constituting a heat insulating layer of a fixing device Side view of the heat insulating material shown in FIG. Side view showing an example of a laminated structure of heat insulating layers formed in the regions R1 and R2 The side view which looked at the heat insulation layer formed in area | region R1, R2 from the left-right direction of FIG. 4 is a side sectional view of a heat insulating layer formed by alternately stacking a plurality of the heat insulating materials shown in FIG. 4 so that the directions of the thin tubes are orthogonal to each other.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing the internal structure of an image forming apparatus equipped with a fixing device of the present invention. In an image forming apparatus (for example, a printer) 100, when an image forming operation is performed, the photosensitive drum 5 that rotates clockwise in the drawing is uniformly charged by the charging unit 4, and an exposure unit (laser scanning unit) based on document image data. Etc.) An electrostatic latent image is formed on the photosensitive drum 5 by the laser beam from 7, and a developer (hereinafter referred to as toner) is attached to the electrostatic latent image by the developing unit 8 to form a toner image.

  The toner is supplied to the developing unit 8 from the toner container 9. The image data is transmitted from a personal computer (not shown) or the like. Further, a static elimination device (not shown) for removing residual charges on the surface of the photosensitive drum 5 is provided on the downstream side of the cleaning device 19.

  A sheet is conveyed from the sheet feeding cassette 10 or the manual sheet lay 11 via the sheet conveying path 12 and the registration roller pair 13 toward the photosensitive drum 5 on which the toner image is formed as described above. The toner image formed on the surface of the photosensitive drum 5 is transferred onto the sheet by (image transfer unit). The sheet on which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to the fixing device 15 to fix the toner image. The sheet that has passed through the fixing device 15 is conveyed to the upper part of the apparatus by a sheet conveying path 16 and is discharged from a discharge roller pair 17 to a discharge tray 18.

  FIG. 2 is a side sectional view showing an example of the fixing device of the present invention, and FIG. 3 is a perspective view of the upper housing of the fixing device as viewed from the inside. The housing of the fixing device 15 is composed of an upper housing 15a and a lower housing 15b made of resin. A heating roller 20a that rotates clockwise in the drawing is housed in the upper housing 15a, and a counter-roller is housed in the lower housing 15b. A pressure roller 20b that rotates clockwise is accommodated. A heater 21 is built in the heating roller 20a, and the pressure roller 20b is pressed against the heating roller 20a with a predetermined pressure by an urging means (not shown). The heating roller 20a and the pressure roller 20b constitute a fixing roller pair 20 that fixes unfixed toner on the paper P that passes through the fixing nip N. The heater 21 may be a halogen heater or an IH heater including an induction heating unit having an exciting coil and a core.

  The sheet P on which the toner image has been transferred by the transfer roller 14 (see FIG. 1) advances in the left direction in FIG. 2, and is carried into the fixing device 15 from the upstream opening 22a and passes through the fixing nip portion N of the fixing roller pair 20. pass. At this time, the toner image on the paper P is made a permanent image by being heated and pressurized at a predetermined temperature and pressure. Thereafter, the sheet P is conveyed to the outside of the fixing device 15 through the downstream opening 22b, and is discharged to the outside of the image forming apparatus from the discharge roller pair 17 (see FIG. 1).

  The upstream opening 22a is provided with a fixing approach guide 23 for guiding the upper surface of the paper entering the fixing nip N, and a part of the lower housing 15b guides the lower surface of the paper entering the fixing nip N. A fixing approach guide 24 is configured. The leading edge of the sheet is guided to the fixing nip portion N along the guide surfaces of the fixing approach guides 23 and 24. Further, a part of the lower housing 15b constitutes a fixing discharge guide 28 for guiding the paper that has passed through the fixing nip portion N. The fixing discharge guide 28 includes a fixing discharge switch (for detecting the passage of the paper in the fixing nip portion N). (Not shown) is provided.

  A heat insulating layer 30 in which a plurality of sheet-like heat insulating materials are laminated is formed on the inner surfaces of the upper housing 15a and the lower housing 15b, and between the heat insulating layer 30, the heating roller 20a, and the pressure roller 20b, A heat shield plate 31 that reflects the radiant heat of the heating roller 20a is disposed. Further, as shown in FIG. 3, a thermistor 40 that detects the surface temperature of the heating roller 20a at the substantially central portion of the inner surface of the upper housing 15a, and the energization to the heater 21 is cut off when the heating roller 20a exceeds a predetermined temperature. And a thermostat 41 is disposed.

  4 is a plan view showing an example of a heat insulating material constituting the heat insulating layer 30, and FIG. 5 is a side view of the heat insulating material shown in FIG. As shown in FIGS. 4 and 5, the heat insulating material 32 is obtained by joining a sheet material 32a formed of a heat resistant material and a corrugated plate 32b, and has a large number of cross sections between the sheet material 32a and the corrugated plate 32b. A triangular thin tube 33 is formed. In FIG. 4, the crest portion of the corrugated plate 32b is indicated by a solid line, and the trough portion is indicated by a broken line. 4 shows the heat insulating material 32 arranged on the left side with the thermistor 40 of the upper housing 15a shown in FIG. 3 in between. The heat insulating material 32 arranged on the right side of the thermistor 40 includes A hole or notch (not shown) for avoiding interference with the thermostat 41 is formed.

  Since the convection of air in the stacking direction in the heat insulating layer 30 is restricted by the thin tube 33 of the heat insulating material 32, the heat insulating property can be improved. Further, in the longitudinal direction of the upper housing 15a (the axial direction of the heating roller 20a), air can freely move in the narrow tube 33, so that variations in temperature distribution in the axial direction of the heating roller 20a can be reduced. Examples of the heat resistant material constituting the heat insulating material 32 include heat resistant resins such as polyester, polyamide and polyimide, and heat resistant rubber materials such as silicon rubber and urethane rubber. In addition, positioning holes 34 are formed at two locations on the upper and lower sides of the heat insulating material 32 so as to be inserted into positioning bosses (not shown) formed on the inner surface of the upper housing 15a (or the lower housing 15b).

  The thickness T of the sheet constituting the heat insulating material 32 can be used if it is a sheet of 10 mm or less, but a plurality of heat insulating materials 30a and 30b are overlapped along the inner surface shape of the upper housing 15a and the lower housing 15b. In consideration of regulating air convection in the thickness direction of the heat insulating layer 30, the thickness T of the sheet is preferably 1 mm or less.

  Since the convection of air in the stacking direction in the heat insulating layer 30 is limited by the thin tube 33, the thin tube 33 has a close relationship with the heat insulating property of the heat insulating layer 30. That is, the heat insulating property of the heat insulating layer 30 can be easily adjusted by changing the inner diameter of the thin tube 33 of the heat insulating material 32.

  For example, when a small size (A5 size) paper is continuously printed, the non-sheet passing area at both ends of the heating roller 20a is not deprived of heat by the sheet. easy. Therefore, in the central region R1 (see FIG. 3) of the upper housing 15a facing the sheet passing region at the center of the roller, both end portions of the upper housing 15a facing the non-sheet passing region at both ends of the roller while enhancing the heat insulating effect. In the region R2 (see FIG. 3), it is desirable to weaken the heat insulating effect and prevent overheating.

  FIG. 6 is a side view showing an example of a laminated structure of heat insulating layers formed in the regions R1 and R2, and FIGS. 7A and 7B illustrate the heat insulating layers formed in the regions R1 and R2, respectively. 6 is a side view seen from the left-right direction of FIG. In the heat insulating material 32 shown in FIG. 7A, the inner diameter of the narrow tube 33 is about ½ that of the heat insulating material 32 shown in FIG. In the laminated structure shown in FIG. 6, the heat insulating material 32 shown in FIG. 7 (a) is in the central region R1 of the upper housing 15a, and the heat insulating material 32 shown in FIG. 7 (b) is in the regions R2 at both ends of the upper housing 15a. It is arranged. Thereby, in area | region R1 which opposes a paper passing area | region, by restrict | limiting the convection of air with the small diameter small tube 33, heat insulation can be improved and the loss of heat quantity can be suppressed. On the other hand, in the region R2 facing the non-sheet passing region, the excessive temperature rise at both ends of the roller can be suppressed by enlarging the space in which air is convected by the large-diameter narrow tube 33 to promote heat dissipation.

  Further, since the heat insulating material 32 disposed in the region R1 facing the paper passing region and the heat insulating material 32 disposed in the region R2 at both ends are separate members, for example, the heat insulating material 32 having different inner diameters of the thin tubes 33 is used. By preparing a plurality of types, the heat insulating property of the region R2 facing the non-sheet passing region can be varied separately from the region R1. Therefore, when a single fixing device 15 is mounted on a plurality of types of image forming apparatuses 100, the heat insulating property of the heat insulating layer 30 can be easily adjusted by dividing the regions R1 and R2 according to the specifications of the image forming apparatus 100. it can.

  In FIG. 6, the heat insulating property of the heat insulating layer 30 in the regions R1 and R2 is adjusted by making the inner diameters of the thin tubes 33 of the heat insulating material 32 laminated in the regions R1 and R2 different. The same identical insulation 32 can also be used. In this case, the number of the heat insulating materials 32 stacked in the region R1 is made larger than that in the region R2, and the pressure applied to the heat insulating material 32 is increased in the region R1 to compress the heat insulating material 32 and the thin tube 33 is flattened. By squeezing into two, the heat insulating property of the heat insulating layer 30 in the region R1 can be enhanced and the heat dissipation in the region R2 can be promoted similarly to the laminated structure of FIG.

  FIG. 8 is a side view showing another example of the laminated structure of the heat insulating layer 30 formed in the regions R1 and R2. FIG. 8B shows a state in which the laminated structure of FIG. 8A is rotated by 90 °. In the laminated structure shown in FIG. 8, the heat insulating layer 30 is formed by alternately stacking a plurality of the heat insulating materials 32 shown in FIGS. 4 and 5 so that the directions of the thin tubes 33 are orthogonal.

  As shown in FIG. 8, by making the direction of the narrow tube 33 orthogonal, the direction in which the air can move in the narrow tube 33 is also orthogonal in each adjacent layer of the heat insulating layer 30. As a result, air convection in the longitudinal direction of the upper housing 15a is hindered compared to the case where the thin tubes 33 are aligned in the same direction as shown in FIG.

  In FIG. 8, the heat insulating materials 32 are alternately stacked so that the directions of the thin tubes 33 are orthogonal to each other. However, the region R1 facing the paper passing region of the heating roller 20a and the region R2 facing the non-paper passing region. By increasing or decreasing the ratio of the heat insulating material 32 in which the directions of the thin tubes 33 are orthogonal, the heat insulating property of the heat insulating layer 30 in the axial direction of the heating roller 20a can be adjusted.

  For example, the heat insulating layer 30 shown in FIG. 8 is arranged in the central region R1 of the upper housing 15a, and the heat insulating layer 30 shown in FIG. 6 is arranged in the regions R2 at both ends of the upper housing 15a. Thereby, in area | region R1 which opposes a paper passing area | region, heat insulation can be improved by regulating the convection of air by making the direction of the thin tube 33 in the heat insulation layer 30 orthogonal. On the other hand, in the region R2 facing the non-sheet passing region, the temperature rise at both ends of the roller can be suppressed by aligning the direction of the thin tube 33 and promoting air convection in the longitudinal direction of the upper housing 15a.

  In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the case where the heat insulating layer 30 in which the heat insulating material 32 is laminated is formed on the inner surface of the upper housing 15a has been described. it can.

  In each of the above embodiments, the heat insulating layer 30 and the heat shield plate 31 are provided on the inner surfaces of the upper housing 15a and the lower housing 15b. However, even if the heat insulating effect is provided only on the inner surface of the upper housing 15a facing the heating roller 20a, the heat insulating effect is obtained. I can expect enough. However, in order to more effectively suppress the energy loss due to heat radiation from the fixing roller pair 20, the inner surface of the lower housing 15b facing the pressure roller 20b with the heat insulating layer 30 and the heat shield plate 31 as in the above embodiments. Also preferably provided.

  Further, in each of the above embodiments, the heat insulating material 32 in which the thin tubes 33 are arranged in parallel on one side by joining the sheet material 32a and the corrugated plate 32b is used, but the sheet material 32a and the two corrugated plates 32b are used. The heat insulating layer 30 may be formed by using the heat insulating material 32 in which the thin tubes 33 are arranged in parallel on both surfaces by bonding. Further, the shape of the thin tube 33 is not limited to a triangular cross section, and may be a semicircular cross section, a rectangular cross section, or the like.

  Further, the present invention is not limited to the monochrome printer as shown in FIG. 1, but can be applied to other types of image forming apparatuses such as color printers, monochrome and color copiers, digital multifunction peripherals, and facsimiles. is there.

  INDUSTRIAL APPLICABILITY The present invention can be used for a fixing device mounted on an image forming apparatus, and includes a plurality of sheet-like heat insulating materials in which a plurality of thin tubes are arranged in parallel across the entire area of at least one surface between an inner surface of a housing and a heat shield plate. A heat insulating layer formed by laminating is formed.

  By utilizing the present invention, an energy loss due to heat radiation to the outside of the fixing device can be suppressed as much as possible, and a fixing device with easy adjustment of heat insulation can be provided at low cost.

15 Fixing device 15a Upper housing (housing)
15b Lower housing (housing)
20 Fixing roller pair (fixing member)
20a Heating roller (heating member)
20b Pressure roller (pressure member)
21 Heater (heating means)
22a upstream opening 22b downstream opening 23, 24 fixing approach guide 28 fixing discharge guide 30 heat insulation layer 31 heat shield plate 32 heat insulating material 32a sheet material 32b corrugated plate 33 capillary tube 34 positioning hole 40 thermistor 41 thermostat 100 printer

Claims (9)

A fixing member comprising a heating member having a built-in heating means, and a pressure member pressed against the heating member at a predetermined pressure;
A housing that houses the fixing member and has openings formed on the upstream side and the downstream side in the conveyance direction of the recording medium;
A heat shield disposed in a portion of the inner surface of the housing facing the heating member and reflecting heat radiation from the heating member;
In the fixing device provided with
Between the inner surface of the housing and the heat shield plate, a heat insulating layer formed by laminating a plurality of sheet-like heat insulating materials in which a plurality of thin tubes are arranged in parallel on at least one surface is formed ,
At least a part of the heat insulating material is laminated such that the direction of the narrow tube is orthogonal to the axial direction of the heating member . The heat insulating layer is a ratio of the heat insulating material in which the direction of the thin tube is orthogonal to the axial direction of the heating member in a region facing the paper passing region of the heating member and a region facing the non-paper passing region of the heating member. The fixing device according to claim 1, wherein the two are different from each other . The region facing the sheet passing region of the heating member is formed by laminating a plurality of the heat insulating materials whose inner diameters of the narrow tubes are smaller than the region facing the non-sheet passing region of the heating member. The fixing device according to claim 1 or 2 . The area facing the paper passing area of the heating member is formed by compressing the same heat insulating material as the heat insulating material stacked in the area facing the non-paper passing area of the heating member and stacking a plurality of sheets. The fixing device according to claim 1 or 2 . A fixing member comprising a heating member having a built-in heating means, and a pressure member pressed against the heating member at a predetermined pressure;
A housing that houses the fixing member and has openings formed on the upstream side and the downstream side in the conveyance direction of the recording medium;
A heat shield disposed in a portion of the inner surface of the housing facing the heating member and reflecting heat radiation from the heating member;
In the fixing device provided with
Between the inner surface of the housing and the heat shield plate, a heat insulating layer formed by laminating a plurality of sheet-like heat insulating materials in which a plurality of thin tubes are arranged in parallel on at least one surface is formed,
The region facing the sheet passing area of the heating element constant you wherein the inner diameter of said capillary compared to a region facing the non-paper passing area of the heating member is small the thermal insulator is a number stacked Landing gear. A fixing member comprising a heating member having a built-in heating means, and a pressure member pressed against the heating member at a predetermined pressure;
A housing that houses the fixing member and has openings formed on the upstream side and the downstream side in the conveyance direction of the recording medium;
A heat shield disposed in a portion of the inner surface of the housing facing the heating member and reflecting heat radiation from the heating member;
In the fixing device provided with
Between the inner surface of the housing and the heat shield plate, a heat insulating layer formed by laminating a plurality of sheet-like heat insulating materials in which a plurality of thin tubes are arranged in parallel on at least one surface is formed,
The area facing the paper passing area of the heating member is formed by compressing the same heat insulating material as the heat insulating material stacked in the area facing the non-paper passing area of the heating member and stacking a plurality of sheets. It shall be the constant Chakusochi. The insulation fixing device according to claim 5 or claim 6, characterized in that the direction of the thin tube and the axial direction of the heating member is laminated to match. The fixing device according to claim 1 , wherein the heat shield plate and the heat insulating layer are also provided on a portion of the inner surface of the housing facing the pressure member . An image forming apparatus comprising the fixing device according to claim 1 .