JPH09197880A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize device constitution and to shorten warm-up time by providing a heater and a load bearing structural body inside a fixing roller and constituting the surface side of the load bearing structural body in contact with the fixing roller of low frictional material. SOLUTION: The fixing roller 1 is composed of a thin cylindrical body and the heater lamps 5 and 5 and the fixed type load bearing member 2 are provided inside the roller 1. The member 2 is composed of a circular-arc shaped fixed pad 6 having the radius of curvature smaller than the radius of the roller 1 and a reinforcing member 3, and the surface of the pad 6 in contact with the roller 1 is equipped with a coating film 'metallic coat' which is conductive anodic oxidation processed so as to impregnate hard anodized aluminum with silver ion. The reinforcing member 3 is provided on the upper side of the pad 6 in order to correct the deformation of the pad 6, and its surface is high glossily chromeolated so as to prevent the absorption of heat from the lamp 5. Thus, even when the fixing roller is composed of the thin cylindrical body, it is hardly deformed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for passing an unfixed toner image through a nip region between a fixing roller and a pressure rotator and fixing the toner image with heat and pressure. The present invention relates to a fixing device used in a machine, a facsimile, a printer and the like that uses an electrophotographic process, which can reduce the size of the device and the warm-up time significantly.

[0002]

2. Description of the Related Art In a copying machine using an electrophotographic process, it is necessary to fix an unfixed toner image formed on a recording sheet into a permanent image.
Conventionally, a solvent fixing method, a pressure fixing method, and a heat fixing method are known.

The solvent fixing method has a drawback in that vapor of the solvent is emitted to cause many odors and hygiene problems.
The pressure fixing method has the disadvantage that the fixing property is poor as compared with other fixing methods, and the pressure-sensitive toner used here is expensive. Therefore, neither of these two fixing methods has been widely put into practical use at present.

Therefore, as a fixing method of an unfixed toner image in a copying machine utilizing an electrophotographic process, a heat fixing method of melting the toner by heating and fusing the unfixed toner image on a recording sheet is widely adopted. ing.

FIG. 5 is a diagram showing a schematic structure of a fixing device by the heat fixing method. As shown in FIG. 5, in this fixing device, a heater lamp 3 for heating is provided inside a cylindrical cored bar 32.
1, a fixing roller 30 having a so-called release layer 33 formed of a heat resistant resin coating layer or a heat resistant rubber coating layer on the outer peripheral surface thereof, and a cylindrical core metal 41 arranged in pressure contact with the fixing roller 30. And a pressure roller 40 having a heat resistant elastic body layer 42 formed on the outer peripheral surface thereof. The fixing process of the unfixed toner image is performed by the fixing roller 30 and the pressure roller 4.
The sheet 43 on which the unfixed toner image 44 has been formed is inserted between 0 and fixing by heat melting of the additive of the toner agent is performed.

The heating roller system in which fixing is performed by a heated fixing roller like this fixing device is compared with the hot air fixing system and the oven fixing system of other heating fixing methods.
Since it has high thermal efficiency, it is excellent in terms of low power consumption and high speed, and because it is less likely to cause a flame due to a paper jam, it is currently most widely used.

[0007]

By the way, in the conventional heating roller type fixing device, the time required to raise the surface temperature of the heating roller (fixing roller) from room temperature to a predetermined set temperature (hereinafter referred to as warm-up time). Say)
Requires a long time of 1 minute to 10 minutes. Since the warm-up time is determined by the relationship between the heat capacity of the heating roller and the input power, the heat capacity of the heating roller is small,
If the input power is large, the warm-up time can be shortened, but the heat capacity of the heating roller is limited by the rigidity of the roller, and the input power is limited by the power consumption of the machine of the copying machine.

Generally, the electric power that can be supplied only for fixing is about 300 W to 1200 W, and in order to shorten the warm-up time with the electric power in this range, it is effective to reduce the roll heat capacity of the heating roller. .

However, in order to reduce the roll heat capacity,
When the roll diameter and the wall thickness of the roll core are reduced, the roll rigidity is also reduced at the same time, and the load required for fixing cannot be applied. Incidentally, the heat capacity of the roll is proportional to the square of the roll diameter, while the roll rigidity is proportional to the fourth power of the roll diameter. Therefore, when the diameter of the roll is equal to or smaller than a predetermined roll diameter, the roll rigidity suddenly decreases, the roll bends, and it becomes impossible to apply a load necessary for fixing.

In order to solve these problems, various roll strength reinforcing techniques and roll radius correction techniques have been conventionally proposed. For example, in the "heat fixing device in a copying machine" described in JP-A-59-30571 and JP-A-59-128665, a heat insulator is provided inside a sleeve composed of a thin plate having a small heat capacity. A roll strength reinforcing technique is used in which one or more inner frames for supporting the sleeve via the inner frame are arranged between both supports to have flexibility.

Further, in the "pressure fixing device" described in Japanese Patent Application Laid-Open No. 56-60471, a disk is fitted as a fulcrum member on the pressure shaft, and the pressure shaft is inserted in the upper and lower hollow pipe roller pairs. A roll radius correction technique is used in which a load is applied to both ends of the hollow pipe roller to bend the shaft of the pressing portion to obtain a uniform pressure on the pair of hollow pipe rollers. Further, as a technique related to the roll deviation correction technique of this type of heat fixing device, there are disclosed in Japanese Patent Laid-Open No. 4-44074 and Japanese Patent Laid-Open No. 4-4407.
No. 5, JP-A-4-372974, etc., an endless film or belt is used in place of a rigid roll (fixing roller), and a heating and pressure-contacting member fixed inside the belt is arranged to ensure uniform heating. There is a proposal of a technique for obtaining a pressure part.

Further, Japanese Patent Laid-Open No. 6-43775 discloses that
In a heat fixing device in which a backup roller of a pressure member is pressed with a constant pressure against a hollow heat roller that houses a resistance heating element inside, an arc-shaped protrusion corresponding to the inner peripheral surface of the heat roller that fixes the resistance heating element. There is a proposal of a thermal fixing device having a heat transfer plate having a portion formed therein and configured to heat the heat roller via the heat transfer plate with heat from the resistance heating element.

The inventors of the present invention have studied the techniques of these heating roller type fixing devices and made improvements, and as a result, based on the strength test results of a thin fixing roller bearing both ends,
It has been found that roll breakage can be divided into two forms: stress in the axial direction of the roller (bending stress) and stress in the circumferential direction (stress of dents). In particular, when a thin roll is used as a fixing roller, the stress in the circumferential direction exceeds the stress in the axial direction with respect to the thin roll, so the stress in the circumferential direction is the main factor of roll failure. Axial stress can be reduced, for example, by a radius correction technique such as a backup roll, but there is no correction technique that reduces stress in the circumferential direction.
Therefore, in the fixing device according to the related art, there is a limit to the thinning of the fixing roller, and there is a problem that the device structure cannot be downsized and the warm-up time cannot be shortened.

The present invention has been made to solve these problems, and the first object of the present invention is to use a thin-walled cylindrical body as a fixing roller, which can reduce the size of the apparatus. The object of the present invention is to provide a fixing device capable of significantly reducing the warm-up time. A second object of the present invention is to provide a fixing device which is compact and can apply a relatively large pressure contact load for fixing, and which has high-speed fixing performance.

[0015]

In order to achieve the above object, the fixing device of the present invention allows an unfixed toner image to pass through a nip region between a fixing roller and a pressure rotator, and heat and pressure are applied thereto. In a fixing device for fixing, a fixing roller composed of a thin-walled cylindrical body, a heater for heating the fixing roller, a pressure rotating body contacting the fixing roller with a predetermined pressure, and a thin-walled cylindrical body of the fixing roller. A load receiving structure that is provided inside and receives a load from the pressure rotating body; and a low friction member that is provided on at least a surface side of the load receiving structure that contacts the fixing roller. .

Further, in the fixing device of the present invention, the low friction member provided on at least the surface side of the load receiving structure which comes into contact with the fixing roller is a metal-impregnated hard alumite coating or a filler-containing fluororesin coating. And
In this case, in the load receiving structure of the fixing device, at least the surface side of the load receiving structure that contacts the fixing roller has an arc shape and a radius of curvature r, and with respect to the radius R of the fixing roller,
It is characterized in that r ≦ R.

Further, in the fixing device of the present invention, in order to improve the sliding state between the fixing roller and the load receiving structure, a surface of the fixing roller and the load receiving structure which contacts at least the fixing roller. It is characterized in that a lubricant is arranged between it and the side. The lubricant in this case is characterized by using a grease selected from ester synthetic oil, synthetic hydrocarbon oil, phenyl ether synthetic oil, fluorosilicone synthetic oil, or fluorine synthetic oil. Further, in order that the lubricant is well adapted to the sliding surface of the load receiving structure, a groove is provided in the longitudinal direction on the surface side of the load receiving structure which comes into contact with the fixing roller, and the lubricant is arranged in the groove. It is characterized by

In the fixing device of the present invention having various characteristics as described above, the fixing roller, the heater, the pressure rotator, and the load receiving structure are main components. The fixing roller is composed of a thin-walled cylinder, and the heater heats the thin-walled cylinder of the fixing roller. The pressure rotator contacts the heated fixing roller at a predetermined pressure. As a result, a nip area is formed between the fixing roller and the pressure rotator, the unfixed toner image transferred onto the recording paper is passed through the nip area, and the unfixed toner image is formed by heat and pressure. Settles in. Here, a load receiving structure is further provided inside the thin-walled cylindrical body of the fixing roller, and the load receiving structure applies a predetermined pressure to the fixing roller by receiving the load from the pressure rotating body. And acts so as to press the fixing roller against the pressure rotating body.

In this case, in order to allow the cylindrical body of the fixing roller and the load receiving structure to slide in a pressed contact state, the load receiving structure has at least a surface side in contact with the fixing roller. Provide a low friction member. Further, at least the surface side of the load receiving structure that contacts the cylindrical body of the fixing roller has an arc shape and a radius of curvature r, and the radius R of the fixing roller is R.
On the other hand, r ≦ R. As a result, the load receiving structure and the fixing roller are in contact with each other at a substantially axially symmetrical center position of the load receiving structure, and pressure can be appropriately applied by the load in the nip region of the fixing roller.

Further, in order to improve the sliding state between the fixing roller and the load receiving structure, a lubricant is provided between at least the surface side of the load receiving structure which contacts the fixing roller. Further, a groove is provided in the longitudinal direction and the lubricant is arranged in the groove so that the lubricant is well adapted to the surface side of the load receiving structure that comes into contact with the fixing roller. This particularly improves the sliding state between the fixing roller and the load receiving structure at the time of starting.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, modes for carrying out the present invention will be specifically described with reference to the drawings. FIG.
FIG. 3 is a cross-sectional view illustrating the configuration of the fixing device according to the exemplary embodiment of the present invention. In FIG. 1, 1 is a fixing roller composed of a thin cylindrical body, 2 is a load receiving member, 3 is a reinforcing member, 4 is a pressure rotator, 5 is a heater lamp, 6 is a fixed pad, 7 is a nip region, and 8 is. Is a finger for removing adhered toner, 9 is a temperature sensor, 23 is recording paper on which a toner image is fixed, 24 is recording paper, and 25 is an unfixed toner image.

Description will be made with reference to FIG. The fixing roller 1 is composed of a thin-walled cylindrical body, for example, a nickel core having a radius of 17.5 mm, a wall thickness of 0.15 mm and a length of 335 mm, and a fluororesin (Teflon: trade name of DuPont) as a release layer.
Used to have a thickness of 30 μm. Two heater lamps 5 serving as a heating source are arranged at the center of the fixing roller 1. As the heater lamp 5, for example, 100v,
A 600w halogen lamp is used.

The temperature sensor 9 detects the surface temperature of the fixing roller 1 and controls the temperature of the fixing roller 1 so that the surface temperature of the fixing roller 1 is always 150 ° C. by a temperature controller (not shown). Since a thin cylindrical body is used as the fixing roller here, the warm-up time at this time can be 9 seconds. The fixing roller 1 is directly driven by a drive motor (not shown) at a speed of 250 mm / s. A fixed type load receiving member 2 is provided inside the cylindrical body of the fixing roll 1.

The load receiving member 2 has a radius 1 of the fixing roller 1.
It is composed of an arc-shaped fixed pad 6 having a radius of curvature of 16 mm, which is smaller than 7.5 mm, and a reinforcing member 3. The surface of the fixing pad 6 that is in contact with the fixing roller 1 is provided with a film (metal coat processed by Soken Kako Co., Ltd.) that is conductive anodized so as to impregnate hard alumite with silver ions. In the load receiving member 2, the reinforcing member 3 is provided on the upper side of the fixed pad 6 in order to correct the deformation of the fixed pad 6.
Substantially, the reinforcing member 3 receives a load from the pressure rotating body 4. The surface of the reinforcing member 3 is plated with high-gloss chromium in order to prevent absorption of heat from the heater lamp 5 of the heating source provided inside the cylindrical body of the fixing roller 1.

Therefore, the fixing roller 1 constituted by the thin-walled cylindrical body hardly deforms even under a load of 50 kg, and functions sufficiently as the fixing roller 1. The pressure rotator 4 here has, for example, an outer diameter of 30 mm, a wall thickness of 0.5 mm,
A 310 mm long stainless steel core with a thickness of 5.0 mm
It is composed of silicone rubber coated with. Both rolls of the fixing roller 1 and the pressure rotator 4 are 100K.
Rotate under pressure with a load of g. At this time, the width of the nip area is 7.5 mm.

The position of the fixing roller 1 is supported by both ends of the roll of the fixing roller 1 so that the position of the fixing roller 1 does not change due to the driving force of its rotation or the pressure contact force from the pressure rotating member 4. Since the load receiving member 2 receives the substantial pressure contact force, the load on the bearing portions at both ends of the fixing roller 1 is small. Therefore, a bearing having a simple structure is sufficient.

In the fixing process by the fixing device constructed as described above, the recording paper 24 on which the transferred unfixed toner image 25 is transferred is transferred to the nip area 7 between the fixing roller 1 and the pressure rotator 4. Through the insertion, the heat from the heater lamp 5 of the fixing roller 1 and the pressing force between the fixing roller 1 and the pressure rotator 4 fix the unfixed toner image 25 by heat melting the additive of the toner agent. , Recording paper 2 with the toner image fixed
Discharge 3.

In this case, the load receiving member 2 slides on the portion of the fixed pad 6, and the reinforcing member 3 receives the load from the pressure rotating member 4, so that the fixing roller 1 is always kept at a predetermined pressure. Therefore, the fixing roller 1 comes into contact with the pressure rotating body 4 with a strong load (pressing force) in the nip area 7, and the fixing performance is improved.

As described above, the fixing roller 1 is constituted by the thin-walled cylindrical body, and even if a high load is applied from the inside of the thin-walled cylindrical body of the fixing roller 1 by the load receiving member 2, the fixing roller 1 is destroyed. However, sufficient fixing performance can be obtained.

Further, according to the structure of such a fixing device, since the fixing roller 1 having a thin-walled cylindrical body is structured to be sandwiched between the pressure rotating body 4 and the load receiving member 2, the fixing roller 1 is substantially fixed. The force for bending or denting the roller 1 does not act. That is, unlike the conventional fixing device, since the load from the pressure rotating body 4 is not received by the bearings at both ends of the fixing roller 1, the fixing roller 1 is not bent and the hollow of the cylinder does not occur. Therefore, even if the fixing roller 1 is a thin-walled cylindrical body, a high load can be applied, and the size of the fixing device can be reduced. Further, the warm-up time can be greatly shortened, the fixing speed can be increased, and the instant-on start can be performed.

Further, in this case, in order to improve the sliding state between the fixing roller 1 and the load receiving member 2, the fixing roller 1 and the surface of the load receiving member 2 in contact with the fixing roller 1 are improved. Place a lubricant in between. That is, the load receiving member 2
A lubricant is placed on the fixed pad 6 of. As the lubricant, grease selected from ester synthetic oil, synthetic hydrocarbon oil, phenyl ether synthetic oil, fluorosilicone synthetic oil, or fluorine synthetic oil is used. Further, a groove is provided in the longitudinal direction on the surface side of the load receiving structure which comes into contact with the fixing roller so that the lubricant is well adapted to the sliding surface of the load receiving structure, and the lubricant is arranged in the groove. As a result, the sliding state between the fixing roller 1 and the load receiving member 2 is improved, the movement is smooth even at the time of starting, and the instant-on-start operation can be sufficiently ensured.

Next, specific examples of component parts of the fixing device of the present invention will be individually described. First, the fixing roller 1 will be described.

The fixing roller 1 is required to have a wall thickness of at least a thickness capable of maintaining a cylindrical shape as a roll, a contact type temperature sensor, an offset toner peeling claw, and a releasing agent. Even if a peripheral auxiliary component such as an oil supply device or a cleaning device that comes into contact with the surface at a predetermined pressure is provided, it is necessary to have a wall thickness that does not dent or deform. Considering this point, a metal-based material is desirable as the material of the fixing roller 1. For example, iron, SU
S (stainless steel), aluminum, copper, nickel or the like is used. In this case, the wall thickness is preferably 0.1 mm or more. When a heat-resistant resin roll or ceramic roll is used, its wall thickness is preferably 0.2 mm or more.

The fixing roller 1 is provided with a roll having the above thickness.
When used as, the fixing roller 1 can be directly driven by being mechanically coupled to an external drive mechanism. Further, with such a roll having a large thickness, heat energy sufficient to heat and fix the recording paper (paper) on which the unfixed toner image has been transferred can be stored, so that the surface temperature of the fixing roller 1 can be accurately determined. Even if the temperature cannot be controlled to 150 ° C., if the temperature can be controlled within a predetermined temperature range, for example, a temperature range of (150 ± 10) ° C., the heater lamp 5 as a heating source is repeatedly turned on and off when the fixing roller 1 is passed. Even if it does, uneven fixing performance does not occur.

Further, in the fixing roller 1 made of a thin-walled cylinder, the temperature of the fixing roller 1 is drastically increased even if the fixing roller 1 is rotated after the warm-up is completed because the entire roll is heated by the internal heater lamp 5 during warm-up. It is suitable for high-speed fixing without any problem.

As the pressure rotator 4 applied to the fixing device, a conventionally known pressure roll can be used.
For example, a pressure roll in which the surface of a metal core is coated with a heat-resistant elastic body, or a compound pressure rotary body in which a hollow pressure roll has another pressure roll shaft for correcting axial deviation Alternatively, a pressure belt composed of an endless belt or the like can be used.

Next, the load receiving member 2 will be described.
2 and 3 are views for explaining the structure of the load receiving member that is the load receiving structure of the present invention. When configuring the load receiving member 2, the frictional relationship between the load receiving member 2 and the fixing roller 1 becomes important. That is, the load receiving member 2
2 is provided inside the cylindrical body of the fixing roller 1 and arranged to receive the load from the pressure rotating body 4, and the fixing roller 1 and the pressure rotating body 4 rotate in the fixing process. At this time, the frictional relationship between the load receiving member 2 and the fixing roller 1 must be taken into consideration because the fixing roller 1 slides in contact with the inner surface of the fixing roller 1.

As shown in FIG. 3, the load receiving member 2 is composed of a fixed pad 6 and a reinforcing member 3 for correcting the deformation of the fixed pad 6. Substantially, since the reinforcing member 3 receives a load from the pressure rotating body 4, the reinforcing member 3 is made of an iron-based material or a SUS-based material because of its strength. The length of the reinforcing member 3 is longer than that of the fixing roller 1 in the axial direction.
It is fixed to the base frame of the fixing device outside the both ends of the fixing device. A uniform load can be obtained by preliminarily displacing the central portion by the amount of deflection in consideration of the radius of the reinforcing member 3. Further, the heat capacity of the fixed pad 6 and the reinforcing member 3 is preferably as small as possible from the viewpoint of warming up. In order to reduce the heat capacity, unnecessary parts may be hollowed out except for the necessary parts due to the mechanical structure that receives the load. That is, you may make it hollow or may provide a hole.

The fixing pad 6 is the fixing roller 1 under the conditions of high temperature of 150 to 250 ° C. and high load of 50 to 100 Kgf.
Will slip with the inner surface of. Therefore, heat resistance, slidability, and wear resistance are important properties of the material of the fixed pad 6. As a material that meets these requirements, a polyimide resin, a fluororesin, a polyphenylene sulfide resin, or a saturated polyester resin can be used as the resin base. Or, such resin, glass fiber,
A mixture of carbon, graphite, graphite fluoride, carbon fiber, molybdenum disulfide, fluororesin, etc. can be used. Further, as a metal base, iron, copper, and their sintered oil-containing metals, or molybdenum disulfide, fluororesin, nickel and fluororesin composite plating, or hard alumite impregnated with resin or metal, ceramic As such, silicon carbide ceramics, silicon carbide ceramics, alumina ceramics, and mixtures thereof with molybdenum disulfide, fluororesin, etc. can be used. Among these materials, those suitable for the movement and wear of the fixing roller 1 are preferably hard alumite impregnated with metal and fluorine resin with a filler.

As shown in FIGS. 2 and 3, the fixing pad 6 is basically of a cross section that is arcuate along the fixing roller 1 and extends in the longitudinal direction. It suffices that the width be substantially equal to the nip width with respect to 4. Generally, it is 5 mm to 10 mm. If it is larger than this,
Adhesion with the fixing roller 1 is deteriorated, and heat of the heated fixing roller 1 is taken from the side of the fixed pad 6, resulting in a problem that the warm-up time becomes long.
The radius of curvature r of the arc is r with respect to the radius R of the fixing roller 1.
It is important that ≦ R in terms of movement in the flexible and thin fixing roller 1. Further, as described later, an oil groove (10:
By providing (FIG. 4) in the longitudinal direction, the lubricant is present in the vicinity even after the suspension for a while, and the lubricant can be stably rotated.

Next, the lubricant will be described. As described above, since heat resistance, slidability, and wear resistance are important between the load receiving member 2 and the fixing roller 1, grease as a lubricant is used to satisfy these. The grease is a mixture of thickening agents such as metallic soap and various additives using oils and fats as a base oil, and is mainly used for lubrication. Examples of grease agents that can be used here include ester synthetic oils (base oils are diesters and polyol esters, and lithium stearate and urea are thickeners) and synthetic hydrocarbon oils (base oils are synthetic hydrocarbon oils). , Thickeners containing lithium or urea), phenyl ether synthetic oils (phenyl ether synthetic oils as base oils with urea thickeners), fluorosilicone synthetic oils (fluorosilicone synthetic oils) A grease selected from a base oil blended with a fluororesin or graphite fluoride powder) and a fluorine-based synthetic oil (perfluoroalkylpolyether containing polytetrafluoroethylene powder or graphite fluoride powder) is preferred.

By the way, as a modification of the shape of the fixed pad 6, the lubricant here comes into contact with the inner surface of the cylindrical body of the fixing roller 1 of the fixed roller 6 so that the lubricant is well adapted to the sliding surface of the load receiving member 2. A groove is provided in the longitudinal direction on the surface side, and a lubricant is arranged in the groove. That is, as shown in FIG.
A cross section of an arc along the fixing roller 1 extends in the longitudinal direction, and a groove 10 for temporarily storing a lubricant in the axial direction is further provided in the fixed pad 6. As a result, this groove 10
The lubricant enters the inside, and the familiarity of the lubricant on the arc-shaped surface of the fixed pad 6 is improved. This allows
The sliding state between the fixing roller 1 and the load receiving member 2 is improved, the movement is smooth even at the time of starting, and the instant-on start can be performed.

(Experimental Example 1) In order to evaluate the fixing performance of the fixing device having the above-mentioned structure, the fixing device was equipped with "Vivace 550" manufactured by Fuji Xerox Co., Ltd. Has been established. As a result of this case, sufficient fixability was obtained, and paper wrinkles did not occur at all. Further, no abnormal sound or abnormal movement is generated from the inner surface of the fixing roller 1 due to the sliding of the fixing pad 6 and the fixing roller 1. In this respect as well, there is no difference from the conventional fixing roller type fixing device. I could not find any inferior performance. The movement in No. 1 in the morning one day later was not so good, but it turned out that it was possible to move even if it was bald or somehow without grease.

(Experimental Example 2) In the fixing device having the constitution of Experimental Example 1 described above, a lubricant is further used, and as the lubricant, fluorine-based oil grease (perfluoroalkylpolyether and polytetrafluoroethylene powder) is used. What was put in: Daikin Industry Co., Ltd. product name "Demnum Grease L200") was applied and operated, the movement after 1 day also improved considerably.

(Experimental Example 3) The same configuration as in Experimental Example 2 was used.
An experiment was performed in which the lubricant was changed. As the lubricant in this case, a fluorosilicone synthetic oil grease (a fluorosilicone synthetic oil as a base oil mixed with a fluororesin powder:
When coated with a product name "Fluorosilicone Grease FG721" manufactured by Shin-Etsu Chemical Co., Ltd. and operated, the movement after 1 day was quite good as in Experimental Example 2.

(Experimental Example 4) Further, an experiment was conducted with the same structure as in Experimental Example 2, but using another lubricant. As the lubricant, a phenyl ether synthetic oil grease (a phenyl ether synthetic oil as a base oil with a urea thickener: Kyodo Yushi Co., Ltd., trade name "Multemp ET-"
R ”) was applied and operated, the movement after 1 day was also quite good as in Experimental Example 2.

(Experimental Example 5) Further, an experiment was conducted in which another lubricant was used with the same configuration as in Experimental Example 2. As the lubricant, apply ester synthetic oil grease (base oil is diester or polyol ester, and lithium stearate or urea is a thickener: Kyodo Yushi Co., Ltd. trade name "Multemp 8158") When I operated it,
The movement after 1 day was also quite good as in Experimental Example 2.

(Experimental Example 6) Further, an experiment was conducted with the same composition as in Experimental Example 2, but changing the lubricant. As a lubricant in this case, a synthetic hydrocarbon oil grease (a synthetic hydrocarbon oil as a base oil and lithium or urea added as a thickener: a product name “Multemp SC-S” manufactured by Kyodo Yushi Co., Ltd.) When painted and operated, the movement after 1 day was quite good as in Experimental Example 2.

(Experimental Example 7) Further, as an experimental example in which the low friction material coated on the surface of the fixed pad 6 of the load receiving member 2 in contact with the fixing roller 1 was replaced, the fluororesin was made of TFE enamel (manufactured by Daikin Industries, Ltd.). ), Mixed with glass fiber, graphite, and molybdenum disulfide as a filling material, the fixing pad 6 of the load receiving member 2
Was coated on the side in contact with the fixing roller 1 and tested in the same manner as in Experimental Example 1. The unfixed toner image in this case is the copying machine "Vivac" manufactured by Fuji Xerox Co., Ltd.
The unfixed toner image imaged with "e550" was fixed.
As a result of this case, sufficient fixability was obtained, and paper wrinkles did not occur at all. Also in this case, the fixed pad 6 and the fixing roller 1 are not slipped and no abnormal sound or abnormal movement is generated from the inner surface of the fixing roller 1. In this respect, the conventional fixing roller type is also used. I could not find any inferior performance. The movement at No. 1 in the morning one day later was the same as in Experimental Example 1 and was not so good, but it was found that it was possible to move even if it was bald or somehow without grease. Further, the surface of the fixed pad 6 coated with the material containing the filler was felt to be less worn than the TFE enamel itself.

(Experimental Example 8) Next, an experimental example will be described in which various lubricants are further added under the same conditions as in Experimental Example 7. As the lubricant in this case, a fluorine-based oil grease (perfluoroalkylpolyether with polytetrafluoroethylene powder added) as in each of the above-described experimental examples:
Product name “Demnum Grease L2” manufactured by Daikin Industries, Ltd.
00 ”), a fluorosilicone synthetic oil grease (a fluorosilicone synthetic oil as a base oil mixed with a fluororesin powder: a product name“ Fluorosilicone Grease FG721 ”manufactured by Shin-Etsu Chemical Co., Ltd.), a phenyl ether synthetic oil. Oil grease (phenyl ether synthetic oil as base oil with urea as thickener: Kyodo Yushi Co., Ltd. product name "Multemp ET-R"), ester synthetic oil grease (base oil as diester, polyol Ester with lithium stearate or urea as thickener: Kyodo Yushi Co., Ltd. trade name "Multemp 8158", synthetic hydrocarbon oil grease (synthetic hydrocarbon oil as base oil, lithium as thickener) And urea added: Pay attention to the movement of the fixing roller by using a product name “Multemp SC-S” manufactured by Kyodo Yushi Co., Ltd. But, even in the case of any grease, 1
The movement after day was also quite good as in Experimental Example 2.

(Experimental Example 9) By the way, the limit of the size of the radius of curvature of the fixed pad 6 (a condition of r≤R with respect to the radius R of the fixing roller, where r is the radius of curvature of the arc portion of the fixed pad) is confirmed. Therefore, the fixed pad 6 having a radius of curvature of 18 mm was used, and the test was performed under the same conditions as in Experimental Example 1 except for that. The fixing roller 1 in this case is
As mentioned above, the radius is 17.5 mm, the wall thickness is 0.15 mm,
A 335 mm long nickel core was coated with a fluororesin (Teflon / Dupont Co., Ltd.) as a release layer to a thickness of 30 μm. In this case, the movement of the fixing roller was not so good, and when the fixing pad was removed, scratches were observed at the tip portion, and it seemed that the fixing roller 1 surface was braked. It didn't move after a day.

(Experimental Example 10) Further, in order to confirm the effect of the shape of the modified example of the fixed pad 6 (FIG. 4), the width of the fixed pad 6 on the surface of the fixing roller 1 in contact with the inner surface of the cylindrical body is 1
The oil groove 10 having a depth of 0.8 mm and three oil grooves 10 having a depth of 0.8 mm was provided in parallel with the longitudinal direction in the vicinity of the central portion at intervals of 2 mm, and the test was conducted. Since the grease is stored even if pressure is applied by this groove, the test was performed under the same conditions as in Experimental Example 2 except that such a fixing pad was used. The movement of the fixing roller 1 in this case rotated without stagnation even after one day, and it was judged that the effect was good.

[0053]

As described above, according to the present invention, the fixing device has a novel structure in which the heater and the load receiving structure are provided inside the fixing roller, and the fixing device contacts at least the fixing roller of the load receiving structure. Since the surface side to be used is made of a low-friction material, a thin cylindrical body can be used as the fixing roller. Therefore, the apparatus structure can be downsized and the warm-up time can be greatly shortened. Moreover,
It can be rotated with high reliability even if a load of a predetermined pressure is applied,
It is compact and enables high-speed fixing, and its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the configuration of a fixing device according to an exemplary embodiment of the present invention,

FIG. 2 is a first diagram illustrating a structure of a load receiving member which is a load receiving structure of the present invention;

FIG. 3 is a second diagram for explaining the structure of the load receiving member that is the load receiving structure of the present invention;

FIG. 4 is a view for explaining a modified example of the load receiving structure of the present invention,

FIG. 5 is a diagram showing a schematic configuration of a fixing device by a heat fixing method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixing roller, 2 ... Load receiving member, 3 ... Reinforcing member, 4
... Pressurized rotor, 5 ... Heater lamp, 6 ... Fixed pad, 7
... nip area, 8 ... fingers, 9 ... temperature sensor, 10 ...
Grooves, 23 ... Recording paper on which toner image is fixed, 24 ... Recording paper, 25 ... Unfixed toner image, 30 ... Fixing roller, 31 ...
Heater lamp, 32 ... Cylindrical core metal, 33 ... Release layer, 40
... pressure roller, 41 ... cylindrical core bar, 42 ... heat resistant elastic layer, 43 ... sheet, 44 ... unfixed toner image.

Claims (6)

[Claims] 1. A fixing device configured to pass an unfixed toner image through a nip region between a fixing roller and a pressure rotator and fix the toner image by heat and pressure, the fixing roller having a thin cylindrical body, and the fixing roller. A heater that heats the fixing roller, a pressure rotating body that contacts the fixing roller at a predetermined pressure, a load receiving structure that is provided inside the thin-walled cylindrical body of the fixing roller, and receives a load from the pressure rotating body. A low-friction member provided on at least a surface side of the load receiving structure that contacts the fixing roller. 2. The fixing device according to claim 1, wherein the low friction member provided on at least a surface side of the load receiving structure that contacts the fixing roller is a metal-impregnated hard alumite coating or a filler-containing fluororesin coating. A fixing device characterized by the above. 3. The fixing device according to claim 1, wherein the load receiving structure has an arc shape and a radius of curvature r at least on a surface side of the load receiving structure that contacts the fixing roller, A fixing device, wherein r ≦ R with respect to the radius R of the fixing roller. 4. The fixing device according to claim 1, wherein a lubricant is provided between the fixing roller and at least a surface side of the load receiving structure that contacts the fixing roller. And fixing device. 5. The fixing device according to claim 4, wherein the lubricant is ester synthetic oil, synthetic hydrocarbon oil, phenyl ether synthetic oil, fluorosilicone synthetic oil,
Alternatively, the fixing device is a grease selected from fluorine-based synthetic oils. 6. The fixing device according to claim 4, wherein a groove is provided in a longitudinal direction on a surface side of the load receiving structure which comes into contact with the fixing roller, and a lubricant is arranged in the groove. Fixing device characterized by.