JP2004354670A - Thermal insulation roller and fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image of good sharpness by preventing the drop of a fixing temperature of a nip section. <P>SOLUTION: The thermal insulation roller 30 having a core shaft 31, a thermally insulating layer 32 disposed on the outer periphery of the core shaft 31 and a surface layer 33 disposed on the outer periphery of the thermally insulating layer 32 is provided with an air layer 34 between the core material 32 and the thermally insulating layer 32. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat insulating roller and a fixing device provided in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, a multifunction machine having a plurality of these functions, and a printing machine.
[0002]
[Prior art]
Such a fixing device includes a heating roller having a heating unit, a supporting roller disposed apart from the heating roller, a fixing belt endlessly wound around the heating roller and the supporting roller, and a fixing belt. It has an opposing roller that forms a nip by pressing, guides a recording material onto which a visible image obtained by developing an electrostatic image with toner is transferred to a nip portion, and passes through the nip portion to form a toner image of the recording material. There is one that performs fixing (Patent Document 1).
[0003]
Further, a heating roller having a heating means, a pressure roller having a pressure roller which presses against the heating roller to form a nip, guides a recording material onto which a visible image obtained by developing an electrostatic image with toner is transferred to the nip portion, There is a method in which a toner image on a recording material is fixed by passing through the nip portion (Patent Document 2).
[0004]
[Patent Document 1]
JP-A-2003-76206 (FIGS. 1 to 8 on pages 1 to 6)
[0005]
[Patent Document 2]
JP-A-2003-122170 (FIGS. 1 to 8 on pages 1 to 10)
[0006]
[Problems to be solved by the invention]
In the case of such a fixing device, the fixing temperature of the nip is controlled so that the heat source of the heating roller is maintained at a predetermined temperature because it affects the fixing performance. Heat transfer occurs from the surface to the inside, and the temperature of the roller surface decreases. For this reason, it is difficult to maintain the temperature in the nip at a predetermined temperature, and the fixing may not be sufficient and an image defect may occur.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a heat insulating roller and a fixing device capable of preventing a decrease in a fixing temperature of a nip portion and obtaining an image of good image quality.
[0008]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the present invention is configured as follows.
[0009]
The invention according to claim 1 is a heat insulating roller having a core shaft, a heat insulating layer provided on the outer periphery of the core shaft, and a surface layer provided on the outer periphery of the heat insulating layer.
An adiabatic roller, wherein an air layer is provided between the core shaft and the adiabatic layer.
[0010]
According to the first aspect of the present invention, since the air layer is provided between the core shaft and the heat insulating layer, heat transfer from the heat insulating layer to the core shaft side is interrupted by the air layer, and the roller of the heat insulating roller is provided. A decrease in surface temperature can be prevented, and higher heat insulating properties can be obtained with a simple structure.
[0011]
In the invention according to claim 2, the air space is:
The heat insulating roller according to claim 1, wherein the heat insulating roller is configured by at least one of a groove and a concave portion provided on an outer peripheral surface of the core shaft.
[0012]
According to the second aspect of the present invention, the air layer is formed of at least one of a groove and a concave portion provided on the outer peripheral surface of the core shaft, and the groove may be in an axial direction or a spiral shape, and the cross-sectional shape is , V-shape or U-shape, and is not particularly limited.
[0013]
In the invention according to claim 3, the air space is:
The heat insulating roller according to claim 1, wherein the heat insulating roller is configured by at least one of a groove and a recess provided on an inner peripheral surface of the heat insulating layer.
[0014]
According to the third aspect of the present invention, the air layer is constituted by at least one of a groove and a concave portion provided on the inner peripheral surface of the heat insulating layer, and the groove may be in an axial direction or a spiral shape. May be V-shaped or U-shaped, and is not particularly limited.
[0015]
In the invention according to claim 4, the air space is:
The heat insulating roller according to claim 1, wherein the heat insulating roller is configured by at least one of a groove and a concave portion provided on an outer peripheral surface of the core shaft and an inner peripheral surface of the heat insulating layer.
[0016]
According to the invention described in claim 4, the air layer is constituted by at least one of a groove and a recess provided on the outer peripheral surface of the core shaft and the inner peripheral surface of the heat insulating layer, and the groove is formed in an axial direction or a spiral shape. And the sectional shape may be V-shaped or U-shaped, and is not particularly limited.
[0017]
The invention according to claim 5, wherein the heat insulating layer is
5. A heat insulating paper produced by making short fibers and synthetic pulp from a wholly aromatic polyamide polymer and dispersing it in water, and configured by processing a paper tube. It is a heat insulating roller described in the paragraph.
[0018]
According to the invention as set forth in claim 5, the heat insulating layer is formed by forming a short fiber and a synthetic pulp from a wholly aromatic polyamide polymer and dispersing the same in water, and then manufacturing the heat insulating paper by paper tube processing. Quality and excellent heat insulation.
[0019]
The invention according to claim 6 is characterized in that the heat insulating layer comprises:
The heat insulating roller according to any one of claims 1 to 4, wherein the heat insulating paper is manufactured by impregnating a heat resistant resin into pulp and processed by a paper tube processing.
[0020]
According to the sixth aspect of the present invention, the heat insulating layer is made of a heat insulating paper made by impregnating a heat resistant resin into pulp and processed by a paper tube processing, and is porous and excellent in heat insulating properties.
[0021]
The invention according to claim 7, wherein the heat insulating paper is:
By being laminated in a spiral shape, the range of heat insulation can be freely selected,
7. The heat insulating roller according to claim 5, wherein a range of the heat insulation is from one layer winding to 125 layers depending on the layer thickness in a spiral shape.
[0022]
According to the invention described in claim 7, the range of heat insulation can be freely selected by laminating the heat insulating paper in a spiral shape. Further, the range of heat insulation can be changed from a single layer winding to a layer thickness. Up to 125 layers are stacked in a spiral shape, whereby a parallel flatness with a cylindricality of the surface can be obtained.
[0023]
The invention according to claim 8 is characterized in that the surface layer is made of any one of silicone rubber, silicone sponge, silicone foam, PFA tube, resin coating, and resin surface impregnation. Item 8. The heat insulating roller according to any one of items 7.
[0024]
According to the invention described in claim 8, the surface layer is made of any one of silicone rubber, silicone sponge, silicone foam, PFA tube, resin coating, and resin surface impregnation, and the hardness of the surface is selected by selecting these. Can be set.
[0025]
The invention according to claim 9, wherein a heating roller having a heating unit, a support roller disposed apart from the heating roller, a fixing belt endlessly wound around the heating roller and the support roller, and A pressure roller that presses against the fixing belt to form a nip, guides a recording material onto which a visible image developed with toner has been transferred to the nip portion, and passes the recording material through the nip portion to form a toner image. In a fixing device that performs fixing,
The fixing device according to claim 1, wherein the support roller and / or the pressure roller is the heat-insulating roller according to claim 1.
[0026]
According to the ninth aspect of the present invention, the support roller and / or the pressure roller is the heat-insulating roller according to any one of the first to seventh aspects, and prevents a temperature drop on the roller surface of the heat-insulating roller. Thus, it is possible to obtain a good quality image while maintaining the nip at a predetermined fixing temperature, and to consume power. Further, the nip portion can be set to the fixing temperature in a short time, and the warm-up time of the apparatus can be reduced.
[0027]
The invention according to claim 10 has a heating roller having a heating means, and a pressure roller which presses the heating roller to form a nip, and the recording material on which a visible image developed with toner is transferred is provided. In a fixing device that leads to a nip portion and fixes the toner image by passing through the nip portion,
The fixing device according to claim 1, wherein the pressure roller is a heat insulating roller according to claim 1.
[0028]
According to the tenth aspect of the present invention, the pressure roller is the heat-insulating roller according to any one of the first to seventh aspects. It is possible to obtain an image of good quality while maintaining a predetermined fixing temperature, and it is possible to consume power. Further, the nip portion can be set to the fixing temperature in a short time, and the warm-up time of the apparatus can be reduced.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a heat insulating roller and a fixing device of the present invention will be described. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Further, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning or technical scope of the terms of the present invention.
[0030]
FIG. 1 is a schematic sectional configuration diagram showing an example of the fixing device.
[0031]
The fixing device 1 according to the present invention includes a heating roller 3 having a heating unit 2, a supporting roller 4 disposed separately from the heating roller 3, and a fixing roller endlessly wound around the heating roller 3 and the supporting roller 4. The image forming apparatus includes a belt 5 and a pressure roller 6 that presses the fixing belt 5 to form a nip.
[0032]
In the vicinity of the pressure roller 6, a support roller 7 for applying friction for pressing the fixing belt 5 against the pressure roller 6 is provided, and the heating means 2 of the heating roller 3 is constituted by a heater. The pressure roller 6 is provided with an auxiliary heating means 20.
[0033]
On the surface of the fixing belt 5, oil is supplied from a supply roller 60 and an application roller 61, and a cleaning roller 62 is further provided. The pressure roller 6 is provided with a cleaning roller 63.
[0034]
In an image forming unit disposed in the preceding stage of the fixing device 1, a visible image obtained by developing the electrostatic image with toner is transferred to a recording material P, and the recording material P is guided to a nip 11 by a guide 10. When the recording material P passes through the nip 11, the toner image of the recording material P is fixed, and after the toner image is fixed, the recording material P is separated from the pressure roller 6 by the separation claw 12 and discharged. In the nip portion 11, the recording material P is preheated by the fixing belt 5, and the fixing belt 5 is formed of a material having good thermal conductivity, so that the fixing performance of the toner image is improved.
[0035]
In this embodiment, the support roller 4 is constituted by a heat insulating roller 30 shown in FIGS. 2 is a sectional view of the heat insulating roller, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, FIG. 4 is a side view of the core shaft, FIG. 5 is a sectional view of the groove, and FIG. .
[0036]
The heat insulating roller 30 of this embodiment has a core shaft 31, a heat insulating layer 32 provided on the outer periphery of the core shaft 31, and a surface layer 33 provided on the outer periphery of the heat insulating layer 32. The core shaft 31 is made of, for example, aluminum or the like, and has support portions 31a on both sides. An air layer 34 is provided between the core shaft 3 and the heat insulating layer 32.
[0037]
By providing the air layer 34 between the core shaft 31 and the heat insulating layer 32, heat transfer from the heat insulating layer 32 to the core shaft 31 is blocked by the air layer 34, and the temperature of the roller surface of the heat insulating roller 30 is reduced. The lowering can be prevented, and higher heat insulating properties can be obtained with a simple structure.
[0038]
As shown in FIGS. 4 to 6, the air layer 34 includes at least one of a groove 50 and a recess 51 provided on the outer peripheral surface of the core shaft 31. The groove 50 is formed in the axial direction as shown in FIG. 4A, or is formed in a spiral shape as shown in FIG. 4B. The recesses 51 are formed in the axial direction as shown in FIG. 4C, or are formed in a zigzag as shown in FIG. 4D. Further, as shown in FIG. 4E, a groove 50 and a concave portion 51 may be provided on the outer peripheral surface of the core shaft 31.
[0039]
Further, the cross-sectional shape of the groove 50 may be V-shaped or U-shaped as shown in FIG. 5, and the cross-sectional shape of the concave portion 51 may be V-shaped or U-shaped as shown in FIG. As described above, the air layer 34 is constituted by at least one of the groove 50 and the recess 51 provided on the outer peripheral surface of the core shaft 31, and the groove may be in the axial direction or in a spiral shape, and the cross-sectional shape is V-shaped. Alternatively, it may be U-shaped, and is not particularly limited.
[0040]
In addition, as shown in FIG. 7, the air layer 34 may be configured by at least one of the groove 70 and the concave portion 71 provided on the inner peripheral surface of the heat insulating layer 32. Since the groove 70 and the concave portion 71 are configured in the same manner as the groove 50 and the concave portion 51 of the core shaft 31, the description is omitted.
[0041]
Further, the air layer 34 may be configured by at least one of a groove and a concave portion provided on the outer peripheral surface of the core shaft 31 and the inner peripheral surface of the heat insulating layer 32.
[0042]
The heat insulating layer 32 of this embodiment is formed by forming a short fiber and a synthetic pulp from a wholly aromatic polyamide polymer, dispersing them in water, and processing heat insulating paper manufactured by a paper machine into a paper tube. The heat insulating layer 32 is porous and has excellent heat insulating properties.
[0043]
Further, the heat insulating layer 32 is formed by impregnating pulp with a heat-resistant resin such as a polyimide resin, a bismaleimide resin, a phenol resin, or a heat-resistant epoxy resin, and then performing a paper tube process on the pulp. Excellent heat insulation.
[0044]
The heat insulating paper thus manufactured can be freely selected in a range of heat insulation by being laminated in a spiral shape. For example, the range of heat insulation can be spirally laminated from a single layer winding to 125 layers depending on the thickness of the layer, whereby the thickness of the aramid heat insulating paper is set to, for example, 0.04 mm to 5.0 mm, and the surface of the cylinder is cylindrical. A degree of parallel flatness can be obtained.
[0045]
The heat insulating layer 32 of this embodiment can use, for example, Type 411 manufactured by DuPont Teijin Advanced Paper Co., Ltd. as the heat insulating paper.
[0046]
The surface layer 33 of this embodiment is made of any one of silicone rubber, silicone sponge, silicone foam, PFA tube, resin coating, and resin surface impregnation. With these choices, the hardness of the surface can be set.
[0047]
As the surface layer 33 of this embodiment, for example, a conductive polymer having an electron conjugated system manufactured by Achilles Co., Ltd. is uniformly applied to the surface of a general-purpose plastic substrate (film, sheet, fiber) or the like, and the surface is made conductive. Conductive material can be used.
[0048]
Further, in this embodiment, the pressure roller 6 is provided with the auxiliary heating means 20, but the pressure roller 6 can be constituted by the heat insulating roller 30 shown in FIGS. Thus, the need for the auxiliary heating means 20 is eliminated, and the cost and power consumption of the roller can be reduced.
[0049]
Further, the support roller 7 for giving friction may be constituted by a heat insulating roller 30.
[0050]
In the fixing device 1 of this embodiment, the support roller 4, the support roller 7, and / or the pressure roller 6 are formed of the heat insulating roller 30, so that the temperature of the roller surface of the heat insulating roller 30 can be prevented from lowering. It is possible to obtain an image of good quality while maintaining a predetermined fixing temperature, and it is possible to consume power.
[0051]
Further, since the temperature of the roller surface of the heat insulating roller 30 can be prevented from lowering, the nip 11 can be brought to the fixing temperature in a short time, and the warm-up time of the apparatus can be reduced.
[0052]
FIG. 8 is a schematic sectional view showing another example of the fixing device. The fixing device 1 according to this embodiment includes a heating roller 101 having a heating unit 100 and a pressure roller 102 that presses against the heating roller 101 to form a nip, and a visible image developed with toner is transferred. The recording material P is guided to the nip portion 103, and the toner image is fixed by passing through the nip portion 103.
[0053]
In this embodiment, the pressure roller 102 is constituted by the heat insulating roller 30 shown in FIG. 2 to FIG. 7, so that the fixing temperature of the nip 103 is prevented from lowering, and an image of good image quality can be obtained. Power consumption is possible.
[0054]
Further, since the temperature of the roller surface of the heat insulating roller 30 can be prevented from lowering, the nip 103 can be set to the fixing temperature in a short time, and the warm-up time of the apparatus can be reduced.
[0055]
【The invention's effect】
As described above, according to the first aspect of the invention, by providing the air layer between the core shaft and the heat insulating layer, heat transfer from the heat insulating layer to the core shaft side is blocked by the air layer, and the heat insulating roller is provided. , The temperature of the roller surface can be prevented from lowering, and higher heat insulating properties can be obtained with a simple structure.
[0056]
According to the second aspect of the present invention, the air layer is constituted by at least one of a groove and a concave portion provided on the outer peripheral surface of the core shaft, and the groove may be in an axial direction or a spiral shape, and has a V-shaped cross section. The shape may be a U shape or a U shape, and is not particularly limited.
[0057]
According to the third aspect of the present invention, the air layer is constituted by at least one of a groove and a concave portion provided on the inner peripheral surface of the heat insulating layer, and the groove may be in an axial direction or a spiral shape. The shape may be a letter or a letter U, and is not particularly limited.
[0058]
In the invention described in claim 4, the air layer is formed of at least one of a groove and a recess provided on the outer peripheral surface of the core shaft and the inner peripheral surface of the heat insulating layer, and the groove may be in the axial direction or in a spiral shape, The sectional shape may be V-shaped or U-shaped, and is not particularly limited.
[0059]
According to the invention as set forth in claim 5, the heat insulating layer is made of heat-insulating paper made by making short fibers and synthetic pulp from a wholly aromatic polyamide polymer and dispersing in water, and then processed by paper tube processing, and is porous. Excellent heat insulation.
[0060]
According to the sixth aspect of the present invention, the heat insulating layer is formed by processing a heat insulating paper made by impregnating a pulp with a heat resistant resin into a paper tube, and is porous and has excellent heat insulating properties.
[0061]
In the invention according to claim 7, the range of heat insulation can be freely selected by laminating the heat insulating paper in a spiral shape. Further, the range of heat insulation is from one layer winding to 125 layers depending on the layer thickness. Are spirally laminated, whereby a parallel flatness with a cylindricity of the surface can be obtained.
[0062]
In the invention described in claim 8, the surface layer is formed of any one of silicone rubber, silicone sponge, silicone foam, PFA tube, resin coating, and resin surface impregnation, and the surface hardness is set by selecting these. Can be.
[0063]
According to a ninth aspect of the present invention, the support roller and / or the pressure roller is the heat insulating roller according to any one of the first to seventh aspects, and can prevent a temperature drop on the roller surface of the heat insulating roller, It is possible to obtain an image of good quality while maintaining the unit at a predetermined fixing temperature, and to consume power. Further, the nip portion can be set to the fixing temperature in a short time, and the warm-up time of the apparatus can be reduced.
[0064]
According to a tenth aspect of the present invention, the pressure roller is the heat-insulating roller according to any one of the first to seventh aspects, which can prevent the temperature of the roller surface of the heat-insulating roller from lowering and fix the nip portion to a predetermined fixing position. An image of good quality can be obtained while maintaining the temperature, and power consumption is possible. Further, the nip portion can be set to the fixing temperature in a short time, and the warm-up time of the apparatus can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional configuration diagram illustrating an example of a fixing device.
FIG. 2 is a sectional view of a heat insulating roller.
FIG. 3 is a sectional view taken along line III-III in FIG. 2;
FIG. 4 is a side view of a core shaft.
FIG. 5 is a sectional view of a groove.
FIG. 6 is a sectional view of a concave portion.
FIG. 7 is a cross-sectional view showing an embodiment in which an air layer is provided on the inner peripheral surface of a heat insulating layer.
FIG. 8 is a schematic cross-sectional configuration diagram illustrating another example of the fixing device.
[Explanation of symbols]
Reference Signs List 30 Insulation roller 31 Core shaft 32 Insulation layer 33 Surface layer 34 Air layer

Claims (10)

In a heat insulating roller having a core shaft, a heat insulating layer provided on the outer periphery of the core shaft, and a surface layer provided on the outer periphery of the heat insulating layer,
A heat insulating roller, wherein an air layer is provided between the core shaft and the heat insulating layer. The air layer,
The heat insulating roller according to claim 1, wherein the heat insulating roller is configured by at least one of a groove and a concave portion provided on an outer peripheral surface of the core shaft. The air layer,
The heat insulating roller according to claim 1, wherein the heat insulating roller includes at least one of a groove and a concave portion provided on an inner peripheral surface of the heat insulating layer. The air layer,
The heat insulating roller according to claim 1, wherein the heat insulating roller is configured by at least one of a groove and a concave portion provided on an outer peripheral surface of the core shaft and an inner peripheral surface of the heat insulating layer. The heat insulation layer,
5. A heat insulating paper produced by making short fibers and synthetic pulp from a wholly aromatic polyamide polymer and dispersing it in water, and configured by processing a paper tube. Insulation roller according to Item. The heat insulation layer,
The heat-insulating roller according to any one of claims 1 to 4, wherein the heat-insulating paper is formed by impregnating a heat-resistant resin into pulp to form a paper tube. The insulating paper is
By being laminated in a spiral shape, the range of heat insulation can be freely selected,
The heat insulating roller according to claim 5, wherein a range of the heat insulation is from one layer winding to 125 layers depending on a layer thickness in a spiral shape. 8. The surface layer according to claim 1, wherein the surface layer is made of any one of silicone rubber, silicone sponge, silicone foam, PFA tube, resin coating, and resin surface impregnation. Insulation roller. A heating roller having heating means, a support roller disposed apart from the heating roller, a fixing belt endlessly stretched between the heating roller and the support roller, and a nip pressed against the fixing belt. In a fixing device having a pressure roller for forming a toner image, a recording material onto which a visible image developed with toner is transferred is guided to the nip portion, and the toner image is fixed by passing through the nip portion.
The fixing device according to claim 1, wherein the support roller and / or the pressure roller are the heat insulating rollers according to claim 1. A heating roller having a heating unit, and a pressure roller that presses against the heating roller to form a nip, guides a recording material onto which a visible image developed with toner is transferred to the nip, and passes the nip to the nip. In a fixing device that fixes a toner image by passing through,
The fixing device according to claim 1, wherein the pressure roller is a heat insulating roller according to claim 1.

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