JP4459554B2 - Fixing roller - Google Patents

Description

[0001]
[Industrial application fields]
In the present invention, the outer periphery of the metal core is covered with a sponge, and the outer periphery of the sponge is covered with a thin sleeve. La Related.
[0002]
[Prior art]
For example, in an image forming apparatus such as a copying machine, a printer, or a facsimile, a recording material (transfer material / photosensitive paper / electrostatic recording paper) by an appropriate image forming process mechanism such as an electrophotographic method, an electrostatic recording method, or a magnetic recording method. As a fixing device for heating and pressure-fixing an unfixed toner image formed and supported on a printing paper or the like) in correspondence with target image information by a transfer method (indirect method) or a direct method A so-called two-roller system configuration including a fixing roller and a pressure roller is widely used.
[0003]
FIG. 13 shows a schematic configuration of a conventional two-roller type fixing device. Reference numeral 80 indicates a fixing roller as a heating rotator. Inside the hollow hollow core made of aluminum of the fixing roller 80, a halogen lamp 81 is disposed as a heating means. The halogen lamp 81 is energized from a power source (not shown) to generate heat, and the fixing roller 80 is recorded from the inside of the hollow core metal 82 as a recording material P as a heated material (hereinafter referred to as a transfer material). Heat to a temperature sufficient to melt the toner in the upper toner image.
[0004]
Further, in order to fix the toner on the transfer material P onto the transfer material without offsetting, the outer surface of the hollow core metal 82 of the fixing roller 80 is polytetrafluoroethylene (excellent in releasability). A releasable layer 83 such as PTFE) or perfluoroalkoxytetrafluoroethylene copolymer (PFA) is formed. The thermistor 84 is in contact with the surface of the fixing roller 80, detects the temperature of the surface of the fixing roller, and turns on / off power supply to the halogen lamp 81 so as to heat the toner image on the transfer material at an appropriate temperature. It is configured to perform off control.
[0005]
Reference numeral 90 denotes a pressure roller as a pressure member for the fixing roller 80, which is arranged substantially in parallel with the fixing roller 80, and is urged by pressure springs (not shown) at both ends of the roller. Thus, it is held in pressure contact with the fixing roller 80. The pressure roller 90 includes an elastic layer formed of silicone rubber or a sponge elastic layer 92 formed by foaming silicone rubber on the outside of the metal core 91, and a PTFE or PFA releasability similar to that of the fixing roller 80 on the outer layer. The layer 93 is formed and configured.
[0006]
By configuring the two-roller type fixing device in this way, a sufficient nip width can be formed in the pressure nip N between the fixing roller 80 and the pressure roller 90 by the elasticity of the pressure roller 90. It will be possible.
[0007]
Then, a transfer material P carrying an unfixed toner image is introduced into the nip portion N between the rotated fixing roller 80 and the pressure roller 90 with the image surface facing the fixing roller 80, and is nipped and conveyed. The toner image is heated and pressed and fixed as a permanent image on the surface of the transfer material P by the heat of the roller 80 and the pressure applied at the nip portion N.
[0008]
Here, the hollow core metal 82 of the fixing roller 80 has an outer diameter of 20 to 30 mm and a wall thickness of 1 in order to keep the heat capacity as small as possible and satisfy the mechanical strength while having higher thermal conductivity. .5-3mm was required. Further, the releasable layer 83 constituting the outermost layer cannot be formed thick because of low thermal conductivity, and is usually formed with a thickness of 30 to 50 μm.
[0009]
Further, the pressure roller 90 needs to have a roller surface hardness of about 15 to 60 degrees (ASKER-C, with a load of 300 g) in order to obtain a nip width sufficient for the toner to melt during the transfer of the transfer material P. It was.
[0010]
However, in the case of the two-roller type fixing device as in the conventional example, the thermal conductivity can be increased by reducing the thickness of the hollow cored bar 82 of the fixing roller 80 as much as possible, but the heat capacity is reduced. When the transfer material P is passed, the temperature fluctuation (ripple) on the surface of the fixing roller 80 increases due to the heat radiation to the transfer material P, and thus the toner image on the transfer material P has a non-uniform fixability. Etc. were pointed out.
[0011]
For this reason, in the two-roller type fixing device using the fixing roller 80 and the pressure roller 90, there is a problem that the reduction of the warm-up time required recently is not easily achieved. That is, even when the image forming apparatus is not in operation, the surface of the fixing roller 80 needs to be heated to some extent, and power consumption is large.
[0012]
Further, since the fixing roller 80 is a rigid body and the nip portion N is formed only by the elasticity of the pressure roller 90, the transfer material P is conveyed along the shape of the fixing roller 80. As a result, an external pressure is applied to the transfer material P so as to be bent in a heated state, so that the transfer material P discharged from the fixing device is curled along the curvature shape of the nip portion N. In particular, when the degree is poor, there is a problem that the separation performance from the fixing roller 80 is also adversely affected.
[0013]
Further, when the envelope is passed, there is a problem that wrinkles occur due to the curve or deformation of the envelope, and the printed address is divided by the wrinkles. This is a problem that becomes more apparent as the outer diameter of the fixing roller 80 becomes smaller with the recent miniaturization of the apparatus.
[0014]
Furthermore, when the pressure roller 90 is pressed against the fixing roller 80 by the pressure means at both ends in the longitudinal direction of the pressure roller 90, the small-diameter pressure roller 90 is compared with the central portion in the longitudinal direction due to the deflection of the shaft. The pressure increases as it goes to both ends. For this reason, the width of the nip portion N differs in the longitudinal direction of the nip portion, and becomes larger toward the both end portions than the central portion in the longitudinal direction of the nip portion. As a result, the pressure applied to the transfer material P sandwiched and conveyed by the nip N is different between the center and both ends, and the end of the transfer material is excessively pressurized, so that the paper fibers are stretched and wavy. It was pointed out.
[0015]
In order to solve such a problem, for example, as shown in Japanese Patent No. 3103140, “When an elastic roller is inserted into a sleeve to form a roller, the elastic roller is formed with closed cells. The inner diameter of the sleeve is made smaller than the outer diameter of the elastic roller, and the elastic roller is left in a vacuum apparatus so that the outer diameter of the elastic roller is smaller than the inner diameter of the sleeve, and then the elastic force is applied to the sleeve. It has been proposed to manufacture a fixing roller by a “roller manufacturing method characterized by inserting and integrating rollers”.
[0016]
According to this roller manufacturing method, the above-mentioned problems are solved, and a roller manufacturing method capable of manufacturing a uniform roller in a short time with a high yield is provided.
[0017]
[Problems to be solved by the invention]
However, in the roller manufactured by the manufacturing method described in the above-mentioned registered gazette, an elastic roller having an outer diameter set larger than the inner diameter of the sleeve is left in the vacuum apparatus once to set the outer diameter of the roller. When the outer diameter of the elastic roller and the inner peripheral surface of the sleeve are inserted after being reduced in diameter and the outer diameter of the elastic roller is restored, the frictional engagement force in a so-called compression state is merely used. It is in the state which is only locked by.
[0018]
As a result, when this is used in a state where it is actually rotated and heated as a fixing roller in the fixing device, the rotational driving force is transmitted to the core metal, while the sleeve is pressurized. It will be in rolling contact with the roller. As a result, when the frictional engagement force between the sleeve and the pressure roller becomes strong, a relative rotation occurs between the sponge layer constituting the elastic roller and the sleeve, so that the outer surface of the sponge layer is formed within a short time. It has been pointed out that the problem is that it has become messy and becomes unusable, and there is a strong demand for improvement.
[0019]
Further, in such a state that the fixing roller is driven to rotate, as described above, the sleeve is not fixed to the sponge layer at all, so that the sleeve is displaced along the axial direction with respect to the sponge layer. Can occur. As described above, when the sleeve is displaced along the axial direction with respect to the sponge layer, the edge of the sponge layer comes into contact with the inner peripheral surface of the sleeve, and the stress concentration is partially applied. Become. When stress concentration acts in this way, cracks may occur from this acting part and the sleeve may be broken. From this viewpoint, improvement is strongly desired.
[0020]
Further, in order to ensure the adhesion between the sleeve and the sponge layer, the inner diameter of the sleeve is set to be smaller than the outer diameter of the sponge layer. It has been pointed out that the insertion work (assembly work) becomes difficult when inserting the sponge body in which the structure is disposed, and there is a strong demand for structural improvements from the viewpoint of this assembly workability. .
[0021]
The present invention has been made in view of the above-described circumstances, and a main object of the present invention is to improve the assembly workability of the work of assembling the sponge body into the sleeve when manufacturing the fixing roller. Low La Is to provide.
[0022]
Another object of the present invention is to improve the assembling workability and to maintain a usable state for a long period of time even in a state of actual rotational driving. La Is to provide.
[0023]
Another object of the present invention is to improve the assembly workability and to adhere between the sponge and the thin sleeve so that the gap between the outer peripheral surface of the sponge and the inner peripheral surface of the thin sleeve is along the circumferential direction. This prevents the relative movement of the sponge and ensures that the outer peripheral surface of the sponge is shaky and avoids the situation where the sponge has a long life. La Is to provide.
[0024]
Another object of the present invention is to improve the assembly workability and to bond the sponge and the thin sleeve in the axial direction between the outer peripheral surface of the sponge and the inner peripheral surface of the thin sleeve. This is a fixing roller that can prevent the relative movement along the sleeve and effectively suppress the occurrence of cracking due to stress concentration due to the edge of the sponge layer hitting the sleeve. La Is to provide.
[0025]
[Means for Solving the Problems]
In order to solve the above-mentioned problems and achieve the object, the fixing roller according to the present invention is arranged according to claim 1 so as to surround the cored bar and the outer periphery of the cored bar. A sponge layer made of silicone rubber and having an Asker C hardness of 300 g load set in a range of 15 to 60 degrees, and a nickel electroformed thickness bonded to the outer periphery of the sponge layer via an adhesive layer A thin sleeve having a metal layer having a thickness of 10 to 200 μm, and a release layer disposed on the outer periphery of the thin sleeve so as to cover it In addition, an elastic layer is formed between the thin sleeve and the release layer, The outer diameter of the sponge layer and the inner diameter of the thin sleeve are set to be the same before the sponge layer is inserted into the thin sleeve, and the adhesive layer has a thickness of 5 to 100 μm and is cured. It is characterized by comprising a silicone rubber-based adhesive made of an addition LTV, which is a rubber-based adhesive having a predetermined elasticity.
[0030]
Also, a fixing roller according to the present invention is as follows. 2 According to the description, the adhesive layer is formed over the entire circumference.
[0034]
Also, a fixing roller according to the present invention is as follows. 3 According to the description, the release layer is made of a fluororesin.
[0035]
Also, a fixing roller according to the present invention is as follows. 4 According to the description, the release layer is formed of a fluororesin layer applied to the outer periphery of the thin sleeve.
[0036]
Also, a fixing roller according to the present invention is as follows. 5 According to the description, the release layer is formed of a fluororesin tube coated on the outer periphery of the thin sleeve.
[0038]
Also, a fixing roller according to the present invention is as follows. 6 According to the description, the elastic layer is made of silicone rubber.
[0039]
Also, a fixing roller according to the present invention is as follows. 7 The elastic layer is formed so as to have a thickness of 10 to 500 μm.
[0040]
Also, a fixing roller according to the present invention is as follows. 8 According to the description, the sponge layer includes open cells.
[0041]
Also, a fixing roller according to the present invention is as follows. 9 According to the description, the thin sleeve is a laminate including at least a heat-resistant synthetic resin layer and a metal layer.
[0044]
Also, a fixing roller according to the present invention is as follows. 10 The heat-resistant synthetic resin layer is made of polyimide resin.
[0050]
DESCRIPTION OF PREFERRED EMBODIMENTS
Hereinafter, various embodiments of a fixing roller according to the present invention and a two-roller type fixing device including the fixing roller will be described in detail with reference to the accompanying drawings.
[0051]
(Description of the first embodiment)
First, a schematic configuration of a fixing device 10 according to a first embodiment of the present invention will be described with reference to FIG. Reference numeral 12 denotes a fixing roller as a heating rotator to which the fixing roller of the first embodiment according to the present invention is applied. Reference numeral 14 denotes a predetermined roller on the fixing roller 12. A pressure roller is shown as a pressure member that rolls in contact with pressure. A thermistor 38 for measuring the surface temperature is disposed in contact with the outer peripheral surface of the fixing roller 12.
[0052]
The fixing roller 12 is rotationally driven in a direction indicated by an arrow by a drive system (not shown) through a drive gear (not shown) at a longitudinal end of a drive shaft of a metal core 16 made of metal such as iron. On the other hand, the pressure roller 14 is pressed against the fixing roller 12 by a pressure spring (not shown) via bearings (not shown) at both ends of the iron core 18 in the longitudinal direction. Rotate in the direction indicated by the arrow following the rotation. Reference numeral N indicates a pressure nip where the rollers 12 and 14 are in rolling contact with each other.
[0053]
As shown in FIG. 2, the fixing roller 12 according to the first embodiment includes a cored bar 16 and a sponge layer disposed around the cored bar 16 via a primer 20 so as to surround the cored bar 16. 22, a thin sleeve 26 bonded to the outer periphery of the sponge layer 22 via an adhesive layer 24, and a release layer 28 disposed on the outer periphery of the thin sleeve 26 so as to cover it. It is configured.
[0054]
Here, the above-described sponge layer 22 is composed of a sponge body containing open cells formed by foaming silicone rubber. The sponge layer 22 is formed of a sponge body inserted into the thin-walled sleeve 26, and an outer diameter polishing (not shown) is performed so that the outer diameter thereof is the same as the inner diameter of the sleeve 26 before the insertion. It is processed by the device. Specifically, the inner diameter of the thin sleeve 26 and the outer diameter of the sponge body before insertion are both set to 30.0 mm.
[0055]
As a result, in the fixing roller 12 assembling step, the sponge layer 22 disposed so as to surround the cored bar 16 via the primer 20 is inserted into the thin sleeve 26 through the primer 20, and the adhesive layer 24. When the thin sleeve 26 is bonded to the outer periphery of the sponge layer 22 through the inner diameter of the sponge layer 22, the inner diameter of the thin sleeve 26 and the outer diameter of the sponge body before insertion are the same diameter. Thus, the insertion operation (assembly operation) can be carried out very easily, and the assembling workability in assembling can be greatly improved.
[0056]
Further, the thin-walled sleeve 26 is formed of a metal material having a high thermal conductivity, such as iron, SUS, or nickel. Specifically, in this embodiment, the thin sleeve 26 is formed of a nickel electroformed sleeve and has an inner diameter of 30. 0.0 mm and a wall thickness of 10 to 200 μm, preferably 30 to 50 μm. Specifically, in this embodiment, it is formed as a thin sleeve having a wall thickness of 35 μm.
[0057]
Further, in order to bond the sponge layer 22 and the thin sleeve 26 described above, at least one of the outer peripheral surface of the sponge layer 22 and the inner peripheral surface of the thin sleeve 26, specifically, in the first embodiment, the sponge layer 22 Prior to insertion of the thin sleeve 26 into the outer periphery of the layer 22, an adhesive is applied over the entire surface to form an adhesive layer 24.
[0058]
Here, as the adhesive constituting the adhesive layer 24, a silicone rubber-based adhesive is used in the first embodiment, and in particular, a two-liquid addition LTV (trade name: SE1700, Toray Dow Corning Silicone) is used. Also, an adhesive of RTV (trade name: KE45, manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.
[0059]
Here, the layer thickness of the adhesive layer 24 is suitably in the range of 5 to 100 μm, and in particular in the first embodiment, it is set to about 50 μm as a conversion from the coating amount. If the thickness of the adhesive layer 24 is less than 5 μm, the adhesive strength is not ensured. On the other hand, if the thickness is more than 100 μm, the heat insulating effect of the sponge layer 22 is impaired, which is not preferable. Therefore, as described above, the optimum thickness of the adhesive layer 24 is 5 to 100 μm.
[0060]
As described above, since the sponge layer 22 and the thin sleeve 26 are bonded to each other, even if the frictional engagement force between the thin sleeve 26 and the pressure roller 14 is increased in the rotation state of the fixing roller 12. The relative rotation between the sponge layer 22 and the thin-walled sleeve 26 does not occur, and the outer surface of the sponge layer becomes shabby and becomes unusable in a short time, which has been a problem in the past. However, it will be surely prevented, and the effect is enormous.
[0061]
Further, in such a rotation state of the fixing roller 12, the thin sleeve 26 is bonded and fixed to the sponge layer 22, so that the thin sleeve 26 is reliably prevented from being displaced along the axial direction with respect to the sponge layer 22. Will be. As a result, the occurrence of cracking due to stress concentration, which was generated by the displacement of the thin sleeve 26 along the axial direction with respect to the sponge layer 22, is reliably prevented. The effect is tremendous.
[0062]
Further, by adopting a silicone rubber adhesive as the adhesive constituting the adhesive layer 24, the adhesive itself can exhibit predetermined softness and elasticity. As a result, when the soft sponge layer 22 and the hard thin sleeve 26 are bonded, the difference in hardness between the two can be effectively absorbed and no significant stress can be exerted. It is.
[0063]
Further, since the adhesive layer 24 has a predetermined elasticity as described above, it prevents the force from the hard thin sleeve 26 from being directly transmitted to the sponge layer 22, so-called protection. The function as a layer can be exhibited.
[0064]
The release layer 28 is made of a fluororesin such as PTFE or PFA. For example, it may be formed by applying PFA to the outer peripheral surface of the thin-walled sleeve 26, or may be formed by covering a PFA tube.
[0065]
On the other hand, the pressure roller 14 is formed by sequentially forming an elastic layer 30 made of silicone rubber and a release layer 32 such as PTFE or PFA on the outer periphery of the cored bar 18.
[0066]
Reference numeral 34 denotes a halogen heater as external heating means for heating the surface of the fixing roller 12 from the outside. The halogen heater 34 is disposed in the vicinity of the transfer material entrance of the pressure nip N between the fixing roller 12 and the pressure roller 14 so as to face the fixing roller 12. The surface is adapted to be heated.
[0067]
Here, in order to efficiently perform the radiant heating of the fixing roller 12 by the halogen heater 34, a curved reflecting plate 36 having a high reflectance is disposed on the opposite side of the fixing roller 12 with the halogen heater 34 in the middle. The radiant heat from the halogen heater 34 is reflected to the fixing roller 12 side without being diffused.
[0068]
The thermistor 38 for detecting the surface temperature of the fixing roller is in contact with the fixing roller 12 described above, and the surface temperature information of the fixing roller 12 detected thereby is converted into an A / D converter ( Is sent to a CPU (not shown) via an unillustrated CPU, and based on this, the CPU (not shown) controls ON / OFF of the halogen heater 34 via an AC driver (not shown), thereby fixing the fixing roller. The surface temperature of 12 is controlled to a predetermined value.
[0069]
Other external heating methods for the fixing roller 12 include induction heating using a heating coil 40 as shown in FIG. This is particularly effective when a ferromagnetic material such as iron, nickel, or cobalt is used as the thin-walled sleeve 26. The heating coil 40 is disposed at a predetermined interval from the surface of the fixing roller 12.
[0070]
4 is an enlarged perspective view of one end side of the heating coil 40 shown in FIG. The heating coil 40 is a horizontally long member substantially corresponding to the length dimension of the fixing roller 12 and is arranged substantially parallel to the fixing roller 12. Reference numeral 42 in the figure denotes a horizontally long core made of a ferromagnetic material such as ferrite, and typical shapes generally used for a switching power source include I type, E type, U type, and the like. In this embodiment, an E-type core is used, but a core having another shape can be used. A conductive wire 44 is wound around the core 42 and is energized by a power source (not shown) from the end in the longitudinal direction.
[0071]
With the above configuration, the thin-walled sleeve 26 of the fixing roller 12 energizes a high-frequency alternating current to the conducting wire 44 of the heating coil 40, thereby generating an eddy current in the thin-walled sleeve 26 of the fixing roller 12, and the Joule heat. Induction heating. Also in this case, the surface temperature of the fixing roller 12 is detected by the thermistor 38, and the energization to the heating coil 40 is controlled based on the detection information so that the surface of the fixing roller 12 reaches a predetermined fixing temperature. This heating method enables heating with high energy efficiency and is an efficient fixing method.
[0072]
In the fixing roller 12 described above, in the configuration of the first embodiment, the sponge layer 22 is formed inside and the thin sleeve 26 is formed outside, and the metal sleeve 26 having a small heat capacity and excellent thermal conductivity is provided from the outside. The heating means (halogen heater) 34 can be used to rapidly heat.
[0073]
Here, if the thickness of the thin sleeve 26 is made too thin, there is a problem from the viewpoint of processing, but if the thickness of the thin sleeve 26 is made too thick in order to satisfy the viewpoint of processing, the rigidity becomes strong, There arises a problem that the nip width of the nip portion N cannot be obtained sufficiently. From the above viewpoint, it can be seen that the thin sleeve 26 of the fixing roller 12 is preferably formed with a thickness of 10 to 200 μm.
[0074]
In the fixing roller 12 of the first embodiment, the surface of the fixing roller 12 in which a sponge layer 22 as an elastic body layer having a high heat insulating effect is formed inside, and a thin sleeve 26 having a thickness of 10 to 200 μm is formed outside thereof, By heating to a temperature at which fixing can be performed by the external heating means 34, the warm-up time can be shortened. Therefore, when the image forming apparatus is not operating, it is not necessary to heat the surface of the fixing roller as in the conventional example, and power consumption can be greatly reduced.
[0075]
Further, according to the fixing roller 12 of the first embodiment, the non-uniformity of the pressure nip N caused by the bending of the core 18 of the small-diameter pressure roller 14 due to internal elasticity can be eliminated, and the length of the pressure nip By making the nip width in the hand direction uniform, a similar load is applied to the transfer material, so that defects in the transfer material such as undulation can be prevented.
[0076]
Furthermore, since the fixing roller 12 itself is also elastic, it is easy to set a wide nip width, and the fixing device can also increase the speed of the image forming apparatus.
[0077]
Needless to say, the fixing roller and the fixing device according to the present invention are not limited to the configuration of the first embodiment described above and can be variously modified without departing from the gist of the present invention. Hereinafter, various embodiments of a fixing device and a fixing roller according to the present invention will be described with reference to the accompanying drawings. In the following description, the same parts as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0078]
(Description of the second embodiment)
For example, in the fixing roller 12 of the first embodiment described above, the release layer 28 has been described as being disposed directly on the outer peripheral surface of the thin sleeve 26. However, the present invention has such a configuration. For example, as shown in FIG. 5 as a second embodiment, an elastic layer 46 such as silicone rubber is once formed on the outer peripheral surface of the thin-walled sleeve 26, and the outer peripheral surface of the elastic layer 46 is formed. Needless to say, the release layer 28 may be formed.
[0079]
(Explanation of the third embodiment)
In the fixing roller 12 of the first embodiment described above, the thin sleeve 26 has been described as being formed of a nickel electroformed belt. However, the present invention is not limited to such a configuration. As shown in FIG. 6 as a third embodiment, it may be constituted by a laminate of a synthetic resin layer and a thin metal layer. The thin sleeve 26 used for the fixing roller 12 of the third embodiment will be described below.
[0080]
In the third embodiment, the thin sleeve 26 is constituted by a laminate in which heat resistant synthetic resin layers 26a and thin metal layers 26b are alternately laminated as shown in the figure. Specifically, in the third embodiment, the heat-resistant synthetic resin layer 26a made of, for example, a polyimide resin as a heat-resistant synthetic resin located on the innermost layer, and disposed on the outer layer side surface of the heat-resistant synthetic resin layer 26a. The thin metal layers 26b made of, for example, silver as the metal are alternately stacked, and the outermost layers are laminated so as to end with the heat-resistant synthetic resin layer 26a. Needless to say, the material of the heat-resistant synthetic resin layer 26a is not limited to the above-described polyimide, and polyamide, polyether, PS, PPS, and the like are also applicable. Needless to say, the material of the metal thin layer 26b is not limited to the above-described silver, and iron, nickel, cobalt, and the like can also be applied.
[0081]
Here, the thin metal layer 26b made of silver is set so as to adhere over the entire surface of the heat-resistant synthetic resin layer 26a by vapor deposition in this embodiment, but is limited to such vapor deposition. In addition, it can be deposited by electroless plating (chemical plating), or silver flakes can be used.
[0082]
In addition, when using silver flakes, a polyimide varnish should be used as the heat-resistant synthetic resin layer 26a, and silver flakes may be contained in the varnish. That is, in this case, a laminated unit in which the metal layer 26b made of silver is embedded in the heat-resistant synthetic resin layer 26a is defined. In other words, the laminated unit is made of a heat-resistant synthetic resin layer made of polyimide. And a metal layer made of silver and a heat-resistant synthetic resin layer made of polyimide. The thin-walled sleeve 26 includes at least one laminated unit. As a result, no matter how many laminated units are stacked, the thin-walled sleeve 26 inevitably ends up with the heat-resistant synthetic resin layer 26a in the outermost layer. Will be laminated.
[0083]
Here, the average particle diameter of the silver flakes is preferably in the range of 1 to 15 μm, and the mixing ratio of the polyimide varnish and the silver flakes is determined according to the calorific value required, for example, when self-heating is performed. The volume ratio is preferably in the range of 1: 4 to 1: 1.
[0084]
In the third embodiment described above, the outermost layer of the laminate has been described to end with the heat-resistant synthetic resin layer 26a. However, the present invention is not limited to such a configuration, and FIG. Needless to say, it may be configured to end with the thin metal layer 26b as shown as a modification of the third embodiment. In other words, in this modification, the heat-resistant synthetic resin layer 26a and the metal thin layer 26b are formed as a laminated pair, and at least one or more of the laminated pairs are provided.
[0085]
Here, the thin-walled sleeve 26 may be configured to end with the heat-resistant synthetic resin layer 26a in the outermost layer, or may be configured to end with the thin metal layer 26b, but the thickness of the thin-walled sleeve 26 is the first thickness. As described in the examples, the thickness is preferably in the range of 10 μm to 100 μm.
[0086]
(Description of the fourth embodiment)
Further, the fixing roller according to the present invention has been described as applied to the fixing roller. However, the present invention is not limited to such an application, and as shown in FIG. Needless to say, the fixing roller may be applied to the pressure roller 14.
[0087]
In detail, as shown in FIG. 8, the pressure roller 14 of the fourth embodiment has substantially the same configuration as the fixing roller 12 of the other embodiments described above. It should be noted that the fixing roller 12 to which the pressure roller 14 of the second embodiment is pressed is a core metal 16 in which a halogen heater 34 as a heating source is housed, and directly on the outer periphery of the core metal 16. And a release layer 28 arranged in a regular manner.
[0088]
Even if the fixing roller according to the present invention is applied to the pressure roller 14 as in the fourth embodiment, the same effects as when the fixing roller 12 is applied to the fixing roller 12 can be obtained.
[0089]
(Explanation of the fifth embodiment)
Further, in the above-described fourth embodiment, the fixing roller 12 to which the pressure roller to which the fixing roller according to the present invention is applied is pressed and contacted as the fixing roller 12 and the metal core 16 and the separation disposed directly on the outer periphery thereof. Although the present invention has been described as comprising the mold layer 28, the present invention is not limited to such a configuration, and as shown in FIG. 9 as a fifth embodiment, the core metal 16 and the release layer 28. Needless to say, the elastic layer 58 may be interposed between the two.
[0090]
(Explanation of the sixth embodiment)
In the first to fifth embodiments described above, the fixing roller according to the present invention has been described as being applied to the fixing roller 12 or the pressure roller 14 in the fixing device 10. Without being limited to such application, the fixing roller according to the present invention can be applied to both the fixing roller 12 and the pressure roller 14 as shown in the sixth embodiment in FIG. Needless to say.
[0091]
(Explanation of the seventh embodiment)
Next, the configuration of the seventh embodiment of the fixing apparatus according to the present invention will be described with reference to FIG. The overall configuration of the fixing device 10 of the seventh embodiment is the same as that described with reference to FIG. 1 in the first embodiment, and the fixing roller 12 disposed in the fixing device 10 is the same as that described above. Since the configuration is also the same as the configuration shown with reference to FIG. 2 described above, description thereof is omitted here.
[0092]
In the seventh embodiment, the external heating means in the first embodiment is disposed in a non-contact state with respect to the outer peripheral surface of the fixing roller, but for heating the surface of the fixing roller. A configuration in which the external heating means 50 is brought into direct contact with the outer peripheral surface of the fixing roller 12 is employed.
[0093]
This external heating means 50 forms a low heat capacity energization heating resistor 54 by applying a paste such as silver / palladium alloy powder in the form of a line or strip along the length of the surface of an insulating substrate 52 such as a long and narrow ceramic. A heated plate (ceramic heater) is shown, which is excellent in thermal conductivity and thermal responsiveness, and can rapidly heat the surface of the fixing roller. The surface of the heating plate 50 is coated with a member 56 having good heat resistance and releasability, such as PTFE / PFA, so that it can withstand sliding against the fixing roller 12. The heating plate 50 is pressed against the fixing roller 12 with an appropriate pressure by pressing the back surface of the heating plate 50 with a pressing member (not shown).
[0094]
In the seventh embodiment described above, since an appropriate position on the surface of the fixing roller can be directly heated, the effect of realizing energy-efficient heat fixing can be achieved.
[0095]
(Explanation of the eighth embodiment)
Further, the configuration of the eighth embodiment of the fixing apparatus according to the present invention will be described with reference to FIG. In the eighth embodiment, induction heating by AC magnetic field formation is used as an external heating means for the fixing roller 12, and the heating means is disposed below the nip portion N for fixing the toner image on the transfer material. It is. The configuration of the fixing roller 12 in the fixing device 10 is the same as the configuration shown in FIG.
[0096]
In the eighth embodiment, the thin sleeve 26 of the fixing roller 12 is preferably made of a ferromagnetic material such as iron, cobalt, or nickel. In FIG. 12, reference numeral 60 is the same as that shown in the first embodiment described above, and indicates a heating coil in which a conducting wire is wound around a magnetic core such as ferrite. A cylindrical film 62 made of polyimide, aromatic polyamide, polybenzimidazole or the like is interposed between the fixing roller 12 and the fixing roller 12.
[0097]
The film 62 is sandwiched between the heating coil 60 and the fixing roller 12 by a pressurizing unit (not shown) such as a spring with a constant pressure, and is rotated by the rotation of the fixing roller 12. At this time, since the heating coil 60 and the film 62 slide, the inner surface of the film 62 may be coated with a fluorine resin having excellent wear resistance and releasability. Further, in order to prevent offset and maintain releasability from the transfer material, the outside of the film 62 may be similarly coated with a fluorine resin. Further, even if the fluororesin member having excellent wear resistance and releasability is covered on the fixing roller 12 side of the heating coil 60, the configuration is similarly excellent in durability.
[0098]
The configuration of the heating coil 60 is the same as the configuration shown in FIG. 4 in the first embodiment described above, and a conductive wire is wound around a core made of a ferromagnetic material such as ferrite, and the heating coil 60 is less than the end in the longitudinal direction. Energized by the illustrated power source.
[0099]
With the above configuration, the thin sleeve 26 of the fixing roller 12 applies an AC magnetic field to the thin sleeve 26 of the fixing roller 12 from below the nip portion N by energizing high-frequency alternating current to the conducting wire of the heating coil 60. An eddy current is generated in the thin sleeve 26, and the thin sleeve 26 is induction-heated by the Joule heat. As a result, the surface of the fixing roller in the nip portion N is rapidly heated to melt and fix the toner image on the transferred material.
[0100]
In the eighth embodiment, since the nip portion N is directly heated by energy efficient induction heating, the surface of the fixing roller can be rapidly heated to a temperature at which the toner image on the transfer material can be melted. Establishment is possible. Furthermore, since the induction heating is performed by generating an alternating magnetic field, stable heating can be performed while the transfer material is being conveyed.
[0101]
Further, since the inside of the fixing roller has an appropriate elasticity and a deformable film 62 is used between the fixing roller 12 and the heating coil 60, the width of the nip portion N is the width of the core of the heating coil 40. It can be easily changed by selecting.
[0102]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the assembly workability of the assembly work of the sponge body into the sleeve when the fixing roller is manufactured. Proposed by La Will be served.
[0103]
Further, according to the present invention, it is possible to improve the assembly workability and to maintain the usable state for a long period of time even in the state of being actually driven to rotate. La Will be provided.
[0104]
Further, according to the present invention, the assembly workability is improved, and the sponge and the thin sleeve are bonded to each other, so that the outer peripheral surface of the sponge and the inner peripheral surface of the thin sleeve are relatively aligned in the circumferential direction. It is prohibited to move, and it is possible to avoid the situation where the outer peripheral surface of the sponge is shabby and to ensure a long service life. La Will be provided.
[0105]
Further, according to the present invention, the assembly workability is improved, and the sponge and the thin sleeve are bonded to each other, whereby the sponge outer surface and the thin sleeve inner peripheral surface are relatively aligned in the axial direction. It is forbidden to move and effectively suppresses the occurrence of cracking due to stress concentration due to the sponge layer hitting the sleeve, so that it can extend the service life. La Will be provided.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a configuration of a first embodiment of a fixing device including a fixing roller according to the present invention.
FIG. 2 is a cross-sectional view showing a configuration obtained when the fixing roller according to the first embodiment of the present invention is applied to the fixing roller in the fixing device shown in FIG. 1;
FIG. 3 is a side view showing a schematic configuration of a fixing device using a heating coil instead of a halogen lamp as a modification of the external heating means.
4 is an enlarged perspective view of one end side of the heating coil shown in FIG. 3. FIG.
FIG. 5 is a diagram schematically showing the configuration of a fixing roller according to a second embodiment of the present invention.
FIG. 6 is a diagram schematically showing a configuration of a thin sleeve provided in the fixing roller of the third embodiment of the fixing roller according to the present invention.
7 is a cross-sectional view schematically showing a configuration of a modified example of a thin sleeve provided in the fixing roller of the third embodiment shown in FIG. 6; FIG.
FIG. 8 is a diagram schematically showing a configuration of a fourth embodiment when the fixing roller according to the present invention is applied to a pressure roller.
FIG. 9 is a diagram schematically showing a configuration of a fifth embodiment when the fixing roller according to the present invention is applied to a pressure roller.
FIG. 10 is a diagram schematically showing a configuration of a sixth embodiment when a fixing roller according to the present invention is applied to both a fixing roller and a pressure roller.
FIG. 11 is a diagram schematically showing a configuration of a seventh embodiment of the fixing device according to the present invention;
FIG. 12 is a diagram schematically showing a configuration of an eighth embodiment of the fixing device according to the present invention;
FIG. 13 is a diagram schematically illustrating a configuration of a conventional two-roller type fixing device.
[Explanation of symbols]
10 Fixing device
12 Fixing roller
14 Pressure roller
16 Core metal (for fixing roller)
18 Core metal (for pressure roller)
20 Primers
22 Sponge layer
24 Adhesive layer
26 Thin sleeve
26a Heat-resistant synthetic resin layer
26b thin metal layer
28 Release layer
30 Elastic layer
32 Release layer
34 Halogen heater (external heating means)
36 Reflector
38 Thermistor
40 Heating coil
42 core
44 conductor
46 Elastic layer
50 heating plate
52 Insulating substrate
54 Heating resistor
56 Coating material
58 Elastic layer
60 Heating coil
62 films
N Nip part
P Transfer material (material to be heated)

Claims (10)

With a mandrel,
A sponge layer disposed around the outer periphery of the core metal, made of silicone rubber and set in a range of 15 to 60 degrees with an Asker C hardness of 300 g load;
A thin sleeve having a 10-200 μm thick metal layer made of nickel electroforming bonded to the outer periphery of the sponge layer via an adhesive layer;
A release layer disposed on the outer periphery of the thin sleeve so as to cover it, and an elastic layer is formed between the thin sleeve and the release layer,
The outer diameter of the sponge layer and the inner diameter of the thin sleeve are set the same in the state before the sponge layer is inserted into the thin sleeve,
The fixing roller, wherein the adhesive layer is made of a silicone rubber-based adhesive made of an additional LTV which is a rubber-based adhesive having a thickness of 5 to 100 μm and having a predetermined elasticity in a cured state. . The fixing roller according to claim 1, wherein the adhesive layer is formed over the entire circumference. The fixing roller according to claim 1, wherein the release layer is made of a fluororesin. The fixing roller according to claim 3, wherein the release layer is formed of a fluororesin layer applied to an outer periphery of a thin sleeve. The fixing roller according to claim 3, wherein the release layer is formed of a fluororesin tube coated on an outer periphery of a thin sleeve. The elastic layer includes a fixing roller according to any one of claims 1 to 5, characterized in that it is made of silicone rubber. The elastic layer includes a fixing roller according to any one of claims 1 to 6, characterized in that it is formed to have a thickness of thickness of 10 to 500 [mu] m. The sponge layer is a fixing roller according to any one of claims 1 to 7, characterized in that it comprises an open cell. The thin sleeve fixing roller according to any one of claims 1 to 8, characterized in that a laminate comprising at least heat-resistant synthetic resin layer and a metal layer. The fixing roller according to claim 9 , wherein the heat-resistant synthetic resin layer is made of polyimide resin.

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