JPH06250540A - Heating device - Google Patents

Abstract

(57) [Summary] [Objective] One of the objects of the present invention is to provide a device and a control method without complicating and without increasing the cost.
It is an object of the present invention to provide a heating device capable of preventing heat deterioration and twisting of a pressure roller and a film, wrinkling of a film, and high temperature offset during continuous feeding of small size paper. [Structure] A heat transfer member 12 formed of aluminum or the like is brought into contact with a pressure roller 6 by using a spring 13 to improve heat conductivity in the longitudinal direction of the pressure roller to thereby improve the thermal conductivity between the paper passing portion and the non-paper passing portion. Reduce the temperature difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a heating element is adhered to one side of a heat resistant film and an object to be heated is adhered to multiple sides, and heat energy is applied to the object via the heat resistant film. Heating device.

[0002]

2. Description of the Related Art This apparatus is an image heat fixing device in an image forming apparatus such as an electrophotographic copying machine, a printer or a fax machine, that is, a resin which is heated and meltable by an image forming process means such as electrophotography, electrostatic recording or magnetic recording. To the target image information formed directly or indirectly (transfer) on the surface of the recording material (electrofax sheet, electrostatic recording sheet, recording material sheet, printing paper, etc.) using toner composed of A device that heats and fixes a corresponding unfixed toner image as a permanently fixed image on the surface of the recording material bearing the image. For example, the recording material bearing the image is heated to provide surface properties (gloss, etc.) It can be widely used as a means and a device for heat-treating an image carrier, such as a device for reforming an image carrier, a device for performing hypothetical dressing, and the like.

Hereinafter, as an example of such a heating device,
A heat fixing device used in a copying machine or the like will be described.
As the heat fixing device, for example, JP-A-63-3131 is used.
As disclosed in Japanese Patent Laid-Open No. 82-82, Japanese Patent Application Laid-Open No. 2-157878 and the like, there have been proposed those using a heating body having a rapid temperature rise and a thin film.

FIG. 29 shows an example of such a heat fixing device. This device is a thin heat-resistant film (sheet) 101 and a driving roller 111 for the film 101.
A tension roller 112 that applies tension to the film 101, a heater 106 that is fixedly supported on one side of the film 101 and is fixedly supported, and a heater 106 on the other side. The pressure roller 102 is disposed so as to face the heater 106, and the pressure image roller 102 that makes the visible image bearing surface of the recording material P to be image-fixed adhere to the heater 106 via the film 101. The film 101 is configured to move at the same speed in the forward direction as the recording material P to be image-fixed which is conveyed and introduced between the film 101 and the pressure roller 102 at least during image fixing, A heater 10 with the traveling moving film 101 interposed therebetween.
The recording material P is passed through a fixing nip portion as a fixing portion formed by pressure contact between the pressure roller 6 and the pressure roller 102. As a result, the surface of the recording material P on which the visible image is carried is transferred to the film 10
1 is heated by the heater 106 to apply heat energy to the visible image (unfixed toner image) to soften / melt it, and then the film 101 after passing through the fixing portion and the recording material P are separated at a separation point. By doing so, it has been established.

The heater 1 in the above heat fixing device
The temperature control of 06 is performed by the heater 10 by the thermistor 104.
The thermistor 10 is controlled by controlling the energization of the heating element 105 so that the detected temperature of 6 becomes constant.
No. 4 is always arranged at a position corresponding to the paper passing area so that the paper passing portion has a constant temperature no matter what size recording material is passed.

In such a film heating type fixing device, a heating body having a very small heat capacity and a rapid temperature rise can be used, and the time required for the heater to reach a predetermined heating temperature is greatly shortened to save power. Can be realized.

Further, when the endless belt-shaped film as described above is used, a large offset force is generated in the film, and therefore, the applicant of the present invention has filed in Japanese Patent Application Nos. 2-153602 and 2-153604. We proposed a device in which the endless film is suspended and driven with a margin to reduce the film deviation force and further reduce the driving torque.

An example of such a film heating apparatus is shown in FIG.
It shows in 0. In FIG. 30, 3 is a heater, which has a good conductive substrate 9 and a resistance layer 4 which generates heat when energized.
Reference numeral 1 is a heat insulating holder that heat-insulates and supports the heater 3, and 6 is a pressure roller that also functions as a drive roller that drives the film 2.

[0009]

However, the above-mentioned conventional example has the following problems. First, FIG.
In the conventional apparatus shown in FIG. 1, the thermistor 104 is arranged at a position corresponding to the paper passing portion, and the detected temperature of the heater 106 is always controlled to be constant no matter what size recording material is passed. Since electricity is supplied, for example, when a small size paper such as a B5 size paper, an envelope or a postcard is continuously passed as a recording material, the temperature difference between the pressure roller 102 in the paper passing portion and the non-paper passing portion is about 100 ° C. Become. If continuous feeding of small size paper is continued in such a state, the film is twisted, and in the worst case, the film 101 is twisted and the device is damaged.

Such twisting of the film becomes remarkable when the deviation control of the fixing film is eliminated as shown in FIG. 30 to reduce the cost and downsize.

The main factors that cause the film 101 to twist are the temperature dependence of the strength of the thermal expansion film with respect to the twist of the pressure roller 102 (film thickness, etc.), and the temperature characteristics of the film surface (inner surface) (friction coefficient). , Etc.) and all of these factors have temperature dependence.

It is not yet known in detail how these factors act on the twist of the film, but it is possible to prevent the twist of the film by lowering the temperature of the pressure roller or the film temperature in the non-sheet passing portion. It has been found that there is a significant effect in preventing the outbreak.

Further, if the small size paper is continuously fed for a long time as described above, the pressure roller and the film are thermally deteriorated to shorten the service life of the parts or, in the worst case, damage the apparatus. Therefore, it is necessary to lower the temperature of the non-sheet passing portion in this way.

Therefore, a method of providing a plurality of heater heating patterns and energizing only that area according to the paper size has been proposed, but there is a problem in that the apparatus and the control method become complicated and the cost increases. .

Further, in the above film heating system,
The temperature of the driving roller that drives the film also rises due to heat conduction from the film. Therefore, when a small-sized recording material is continuously processed, the temperature of the drive roller is not uniform in the axial direction due to the temperature rise of the heater and the non-sheet passing portion of the film. Then, the diameter of the drive roller becomes non-uniform in the axial direction due to thermal expansion.

It has been conventionally known that when a shaft for driving an endless film has a taper difference in diameter, the film is displaced in a large diameter direction. By continuously performing the heat treatment, the outer diameter shape of the drive roller in the axial direction is partially displaced as compared with that before the heat treatment, so that the driving of the film is likely to be unstable.

Further, when the film has a thin thickness of 100 μm or less, particularly 50 μm or less and a material having a high elastic modulus such as polyimide is used, the film may be wrinkled if the displacement direction of the film on the drive roller is not uniform. There is also this.

Further, in the tensionless film heating system as shown in FIG. 30 in which the film is driven and conveyed by the pressure roller without applying tension to the film, the pressure roller which also serves as the driving roller is directly heated by the heater through the film. Therefore, the diameter of the drive roller (pressure roller) in the axial direction changes quickly, and the film is likely to be wrinkled.

Further, since there is a difference in the outer diameter of the pressure roller in the axial direction, there is a difference in the feed amount of the film. In particular,
With one-sided reference in which one end of the recording material is conveyed as a reference, if the feed amount differs in the film width direction, the film may be twisted and damaged as described above.

Further, after the small-sized recording material is passed, the fixing film and the pressure roller in the non-sheet passing portion are at high temperature. By the way, the toner becomes over-melted and hot offset occurs.

Further, in the conventional example shown in FIG. 30, since the film traveling is stabilized by using the holder 1 as a guide member, the contact area of the film becomes large and the friction resistance increases. there were.

To solve this problem, the present applicant proposes a method of raising a plurality of ribs substantially parallel to the traveling direction of the film on the guide member to reduce the contact area between the film and the guide member. Proposed.

However, since the film has a small heat capacity,
Where the film is in contact with the guide member, the temperature of the film is strongly influenced by the guide member, and a temperature difference occurs between the rib portion where the film contacts the guide member and the non-contact portion.

In particular, when a rib parallel to the running direction of the film is set up, the portion of the film in contact with the rib is always fixed at a fixed position in the longitudinal direction of the film, so that the temperature of this portion is always constant. It becomes extremely low and uneven temperature occurs on the film.

At this time, when a recording material carrying an unfixed image is passed through the heating device, temperature unevenness of the film appears as a difference in gloss on the image. Alternatively, in the worst case, there is a problem that fixing failure occurs at the position corresponding to the rib on the image.

A first object of the present invention is to solve the above-mentioned problems, to complicate the apparatus and control method, and without increasing the cost, the pressure roller and the film in the continuous feeding of small size paper. Another object of the present invention is to provide a heating device capable of preventing heat deterioration and twisting, wrinkling of a film, and high temperature offset.

A second object of the present invention is to solve the above problems and to provide a film type heating device which does not adversely affect the image due to temperature unevenness even when the film guide member is provided with ribs. To provide.

[0028]

According to the first invention of the present application,
The first purpose is to support a heating body, an endlessly movable film stretched so as to contact the heating body and the supporting body, and to press the heating body through the film. In a heating device, which is provided with a pressing member and which conveys the thermal energy of the heating body to the recording material by sandwiching and conveying the recording material at the pressing portion, a heat transfer member around the pressing member. It is achieved by disposing.

According to the second invention of the present application, the first object is to provide a support for supporting the heating body, and an endlessly movable film stretched so as to contact the heating body and the support. A heating member disposed so as to be in pressure contact with the heating body via the film, and the recording material is sandwiched and conveyed at the pressure contact portion to impart the thermal energy of the heating body to the recording material. In the heating device, it is achieved by setting that the pressure member is provided with a heat transfer member formed to extend in a direction perpendicular to the traveling direction of the recording material.

Further, according to the third invention of the present application, the above-mentioned first object is a support for supporting a heating body, and an endlessly movable film stretched so as to be in contact with the heating body and the support. A heating member disposed so as to be in pressure contact with the heating body via the film, and the recording material is sandwiched and conveyed at the pressure contact portion to impart the thermal energy of the heating body to the recording material. In a heating device, a cooling member having a good heat conductivity and a large heat capacity is arranged so as to contact the film over the longitudinal direction of the film.

Further, according to the fourth invention of the present application, the first object is to provide a support for supporting the heating body, and an endlessly movable film stretched so as to contact the heating body and the support. A heating member disposed so as to be in pressure contact with the heating body via the film, and the recording material is sandwiched and conveyed at the pressure contact portion to impart the thermal energy of the heating body to the recording material. In the heating device, the cooling member having a good heat conductivity and a large heat capacity is arranged in the vicinity of the film so as not to be in contact with the film in the longitudinal direction of the film.

According to a fifth aspect of the present invention, the second object is to provide a heating body supported by a support, an endlessly movable film stretched in contact with the heating body, and the film. A heating member, and a pressing member disposed so as to press-contact the heating body via the film. In the heating device for applying the thermal energy of the body to the recording material, the guide member is arranged on the upstream side and the downstream side in the moving direction of the film around the heating body, and the plurality of ribs are This is achieved by extending in parallel to the moving direction of the film and arranging so that the positions in the direction orthogonal to the moving direction do not overlap on the upstream side and the downstream side.

Further, according to the sixth invention of the present application, the second object is to provide a heating body supported by a support, an endlessly movable film stretched so as to be in contact with the heating body, and the film. A heating member, and a pressing member disposed so as to press-contact the heating body via the film. In the heating device for applying the thermal energy of the body to the recording material, the plurality of ribs are arranged at a predetermined angle with respect to the moving direction of the film.

According to the seventh invention of the present application, the second object is to provide a heating body supported by a support, an endlessly movable film stretched in contact with the heating body, and the film. A heating member, and a pressing member disposed so as to press-contact the heating body via the film. In the heating device for applying the thermal energy of the body to the recording material, the guide member is provided at least on the upstream side in the moving direction of the film with respect to the heating body, and the height of the guide surface on the heating body side is This is achieved by being formed so as to be equal over the entire area in the direction orthogonal to the moving direction.

[0035]

According to the first invention of the present application, when a small-sized recording material such as an envelope or a postcard is continuously nipped and conveyed by the pressure contact portion between the heating member and the pressure member formed through the film,
A temperature difference is generated between the passage area and the non-passage area of the recording material on the surface of the pressure member, and the thermal energy accumulated in the non-passage area is supplied to the heat transfer member disposed around the pressure member, and further, Since the thermal energy accumulated in the heat transfer member is supplied to the passage area, the temperature difference is eliminated and the film is not twisted.

Further, according to the second aspect of the present invention, when a small-sized recording material such as an envelope or a postcard is continuously nipped and conveyed at the pressure contact portion between the heating member and the pressure member formed via the film. Although a temperature difference occurs between the passage area and the non-passage area of the recording material on the surface of the pressure member, the thermal energy accumulated in the non-passage area is supplied to the heat transfer member arranged in the pressure member. Since the heat transfer member is formed so as to extend in the direction perpendicular to the traveling direction of the recording material, the heat energy is supplied to the passage area to eliminate the temperature difference between the two areas. Therefore, the outer diameter of the pressure roller does not change in the axial direction,
The film can be driven stably.

Further, according to the third and fourth inventions of the present application,
When a small-sized recording material such as an envelope or a postcard is continuously nipped and conveyed at the pressure contact portion between the heating body formed through the film and the pressure member, the recording material passage area on the surface of the pressure member is not affected. Although there is a temperature difference in the passing area, the thermal energy accumulated in the non-passing area is supplied to the cooling member in contact with or in the non-contact with the film along the longitudinal direction of the film. Since the cooling member has good thermal conductivity and a large heat capacity, it efficiently accumulates the heat energy in the non-paper passing area and reliably supplies the heat energy to the passing area. As a result, overheating of the non-sheet passing area does not occur,
The heat deterioration of the pressing member and the difference in outer diameter do not occur, and the high temperature offset does not occur.

According to the fifth aspect of the present invention, since the guide member of the film is provided with a plurality of ribs so as to contact the film, the contact area between the film and the guide member is reduced and the frictional resistance is reduced. Is reduced. At this time, a temperature difference occurs between a portion of the film that contacts the rib and a portion that does not contact the rib, but the guide member is provided on the upstream side and the downstream side in the moving direction of the film around the heating body, and the rib is Since it is formed so as to extend parallel to the moving direction, and the position in the direction orthogonal to the moving direction is arranged so as not to overlap between the upstream side and the downstream side, it will come into uniform contact with the film, The temperature difference is eliminated.

Further, according to the sixth aspect of the present invention, since the guide member of the film is provided with a plurality of ribs so as to contact with the film, the contact area between the film and the guide member is reduced and the friction resistance is reduced. Is reduced. At this time, a temperature difference occurs between a portion of the film that contacts the rib and a portion that does not contact the rib, but since the rib is arranged at a predetermined angle with respect to the moving direction of the film, As the area moves, the contact area between the film and the rib increases in the direction orthogonal to the moving direction, thus eliminating the temperature difference.

Further, according to the seventh invention of the present application, since the plurality of ribs are provided on the guide member of the film so as to contact the film, the contact area between the film and the guide member is reduced and the friction resistance is reduced. Is reduced. At this time, a temperature difference occurs between a portion of the film that contacts the rib and a portion that does not contact the rib, but the guide member is provided at least on the upstream side in the moving direction of the film with respect to the heating body, and the heating body side. Since the height of the guide surface is formed so as to be equal over the entire area in the direction orthogonal to the moving direction, the film comes into uniform contact with the guide surface, and the temperature difference is Resolve.

[0041]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view showing a schematic configuration of a tensionless film heating type fixing device as an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a resin-made lateral stay, which serves as an inner surface guide member for a film 2 which will be described later.

2 is an endless heat-resistant film,
It is fitted onto the stay 1 including the heater 3 as a heating body. The inner peripheral length of the endless heat-resistant film 2 and the outer peripheral length of the stay 1 including the heater 3 are larger than those of the film 2 by, for example, 3 mm. The length fits loosely with a margin.

The film 2 has a total thickness of 10 in order to reduce the heat capacity and improve the quick start property.
A single layer of PTFE, PFA, FEP or polyimide, polyamide imide, PEEK, PES, PPS with heat resistance, releasability, strength, durability, etc.
A composite layer film in which PTFE, PFA, FEP or the like is coated on the outer peripheral surface of the above can be used. In this embodiment, a polyimide film having a total thickness of 50 μm in which the outer peripheral surface is coated with PTFE is used.

Reference numeral 3 is a heater as a heating body, and the heater 3 is provided along the substantially central portion of the substrate made of alumina or the like.
As the heating element 4, for example, an electric resistance material such as Ag / Pd (silver-palladium) is applied by screen printing to a thickness of about 10 μm and a width of 1 to 3 mm, and glass or a fluororesin is applied as the protective layer 5 thereon. is doing.

Numeral 10 is a thermistor for the heating element,
The heater thermistor 10 is disposed on the surface of the heater 3 opposite to the side in contact with the fixing film, and the temperature of the heater 3 is controlled by the temperature detected by the thermistor 10.
The position of the thermistor 10 is in the vicinity of the conveyance reference portion in order to secure stable fixing property, and the temperature of the recording material passing portion is always controlled.

Reference numeral 6 denotes a film pressure roller as a rotating body that drives the film 2 by sandwiching the film 2 with the heater 3 to form the fixing nip portion, and includes a stainless shaft 7 having an outer diameter of 8 mm and a length. The surface layer of a silicone rubber having a thickness of 220 mm and a thickness of about 4 mm was coated with a fluorine latex coat (GLS213 manufactured by Daikin Co., Ltd. mixed with 10 wt% of FEP) in an amount of 30 μm and baked, and the hardness was 50 ° C.
(Asker C hardness) roller portion 8, and is driven by driving means (not shown) from the end portion of the stainless shaft 7.

Reference numeral 12 is a plate-shaped heat transfer member for improving the thermal conductivity in the longitudinal direction of the pressure roller and reducing the temperature difference between the paper passing portion and the non-paper passing portion. Abutted against. In this embodiment, the plate-shaped heat transfer member 12 is made of aluminum having good thermal conductivity. Shape is effect,
From the standpoints of space and cost, the wall thickness is 1.5 mm and the width is 20 m
The length was m and the length was 220 mm, and the pressure roller was brought into contact with the entire area in the longitudinal direction.

The fixing device used in this embodiment is shown in FIG.
The one-sided reference configuration is as shown in FIG. 3, and the end portion of the recording material is conveyed along the reference conveyance surface a.

Using the fixing device having the above-described structure and the fixing device shown in FIG. 3 having the same structure as that of the fixing device of this embodiment except for the plate-shaped heat transfer member 12 and the spring 13. An experiment was conducted on the temperature rise of the pressure roller and the twist of the film.

In FIG. 4, the temperature of the heater 3 is controlled to 160 ° C. by using the fixing device shown in FIG. 3, and the envelope (width 105 × length 241 mm) in which the temperature rise in the non-sheet passing portion is set to the process speed (conveyance speed). ) The result of measuring the pressure roller temperature of the paper passing portion and the pressure roller temperature of the non-paper passing portion with a thermography (thermo tracer, manufactured by Niden Sanei Co., Ltd.) when the paper is continuously fed at 24 mm / sec and a paper gap of 150 mm. Is. As can be seen from this figure, the temperature of the pressure roller 6 has a difference of about 60 ° C. when 10 sheets are continuously fed and about 100 ° C. when 20 sheets are continuously fed. In an experiment conducted by the present inventors, when the temperature difference between the paper passing portion and the non-paper passing portion of the pressure roller 6 becomes about 100 ° C. or more,
The film 2 begins to have wrinkles and twists.

Next, FIG. 5 shows the result of the same examination as the above experiment using the fixing device of this example. As can be seen from this figure, the temperature difference between the paper-passing portion and the non-paper-passing portion of the pressure roller 6 is about 70 ° C. even when 30 sheets or more are continuously fed, and 100 sheets of The film was not twisted even when the paper was continuously fed. As described above, the temperature rise in the non-sheet passing portion is reduced because the thermal energy accumulated in the pressure roller on the non-sheet passing portion side where the recording material does not absorb the heat energy is brought into contact with the pressure roller 6. It is considered that the aluminum sheet 12 supplied the sheet to the sheet passing portion side.

Further, the aluminum plate 12 has the effect of heat dissipation. When the temperature of the aluminum plate 12 when actually passing 30 or more envelopes was measured, it was about 200 ° C. on the non-paper passing side and about 150 ° C. on the paper passing side. That is, the aluminum plate 12 has a temperature higher than that of the pressure roller in the paper passing portion, so that the thermal energy accumulated in the non-paper passing portion of the pressure roller passes through the aluminum plate 12 and passes through the paper of the pressure roller. It is understood that it is being supplied to the department.

As described above, when the thermal energy of the non-sheet-passing portion is supplied to the sheet-passing portion of the pressure roller, the temperature detected by the thermistor 10 arranged in the sheet-passing portion becomes difficult to decrease, which causes The number of times the heater that is performing the temperature control is turned on is reduced, and as a result, the temperature rise in the non-sheet passing portion is reduced.

The main factors causing twisting of the film are thermal expansion of the pressure roller, temperature dependence of the twisting of the film (film thickness, etc.), temperature characteristics of the film surface (inner surface) (change in friction coefficient, etc.). Etc., and all of these factors have temperature dependence. Among these, the thermal expansion of the pressure roller has a temperature difference of 100 ° C. and an outer diameter change of about 60 ° C.
It is about 0 μm, and it has been known from the study by the present inventors that the strength against the twist due to the temperature rise in the non-sheet passing portion is increased by increasing the film thickness.

It is not yet known in detail how these factors act on the twist of the film, but it is not possible to lower the temperature of the pressure roller in the non-sheet passing portion or the film temperature by twisting the film. It has been found that there is a remarkable effect in preventing the occurrence of.

From the above, by using the fixing device having the structure shown in this embodiment, the occurrence of twisting of the film is prevented, the fixing device is defective due to the twisting of the film, the paper feeding is defective, and the film is twisted. It is possible to prevent the fixing device from being damaged and being damaged. The surface layer of the pressure roller is a fluorine latex coat (GLS213 manufactured by Daikin Co.,
(A mixture of 10% by weight) was coated with 30 μm and baked, and the heat resistance temperature is about 250 to 26.
It is about 0 ° C. Therefore, it is necessary to raise the temperature of the non-sheet passing portion of the pressure roller to 250 ° C. or less. In the fixing device according to the present exemplary embodiment, since the temperature of the non-sheet passing portion is about 210 ° C.,
It is possible to prevent damage to the pressure roller.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the fixing device of this embodiment, the pressure roller is damaged,
In order to improve the durability life due to dirt and reduce the temperature rise in the non-sheet passing portion of the pressure roller, a cylindrical metal roller is brought into contact with the pressure roller as a heat transfer member. FIG. 6 is a sectional view showing a schematic configuration of the fixing device of this embodiment.

In FIG. 6, reference numeral 14 denotes a metal roller which is in contact with the pressure roller 6, and in this embodiment, aluminum having good heat conductivity is used. The shape is an aluminum roller having an outer diameter of 6 mm and a length of 220 mm in terms of effects, space, cost, etc., and was brought into contact with the entire area of the pressure roller in the longitudinal direction. The fixing device of this embodiment is made of metal (aluminum).
Except for the roller 14, it has the same structure as the fixing device shown in FIG.

Using the fixing device of this embodiment, the temperature rise of the pressure roller was measured and the experiment on the twist of the film was conducted. FIG. 7 shows a heater 3 using the fixing device of this embodiment.
The temperature is controlled to 160 ° C, and the envelopes (width 105 x length 241 mm) where the temperature of the non-sheet-passing parts is severely heated are continuously fed at a process speed (conveyance speed) of 24 mm / sec and a paper interval of 150 mm. It is the result of measuring the pressure roller temperature of No. 1 and the pressure roller temperature of the non-sheet passing portion by thermography.

As can be seen from this figure, the temperature difference between the paper-passing portion and the non-paper-passing portion of the pressure roller is approximately 75 ° C. even when 30 or more sheets are continuously fed, and 100 The film was not twisted even when the sheets were continuously fed.
Similar to the first embodiment, this is because the aluminum roller 14 contacting the pressure roller 6 supplies the thermal energy accumulated in the non-sheet passing portion to the sheet passing portion and that the aluminum roller 14 dissipates heat. It is thought to be due to the effect of.

Next, using the fixing device of the present embodiment and the fixing device of the first embodiment, an experiment of scratches and stains on the pressure roller due to durability was conducted. In the fixing device according to the first exemplary embodiment, plain paper continuous 1
When 0000 sheets are passed, the pressure roller becomes dirty and 5000
Scratches occurred when 0 sheets were passed. On the other hand, in the fixing device of this embodiment, smear occurred when 50,000 sheets of plain paper were continuously passed, but no scratch was generated even when 100000 sheets were passed. In the fixing device of the first embodiment, the aluminum plate 12 is in contact with the pressure roller 6, whereas in the fixing device of the present embodiment, the pressure roller 6 is contacted with the aluminum roller 14 that is a rotating body. Since they are in contact with each other, the durability of the pressure roller is improved.

As described above, by using the fixing device of this embodiment, the twisting of the film is prevented, and the fixing of the film due to the twisting of the film, the paper passing defect, and the film are twisted off. The fixing device can be prevented from being damaged. In addition, the temperature rise of the pressure roller in the non-sheet passing area is set to 250 ° C., which is the heat resistant temperature of the fluorine latex coat on the surface layer of the pressure roller.
Since it can be set as follows, it is possible to prevent the pressure roller from being damaged. Further, in the fixing device of the present embodiment, since the aluminum roller, which is a rotating body, is brought into contact with the pressure roller, the durability of the pressure roller is improved.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The fixing device of this embodiment reduces the temperature rise in the non-sheet passing portion of the pressure roller, and completely prevents the pressure roller from being scratched, soiled, etc. A non-contact heat transfer member is arranged on the pressure roller unit. FIG. 8 is a cross-sectional view showing a schematic configuration of the fixing device of this embodiment.

In FIG. 8, reference numeral 15 denotes a heat transfer member, which is arranged at a predetermined distance from the pressure roller 6 and has the purpose of transferring heat for heating the non-sheet passing portion of the pressure roller. In the example, aluminum having good thermal conductivity was used. The shape is a wall thickness of 1.5 m in terms of effect, space, cost, etc.
m, width 21 mm, length 220 mm, the curvature (diameter) of the curved surface facing the pressure roller was 18 mm, and it was arranged so as to cover an area of 1/3 of the pressure roller. At this time, the gap L with the pressure roller is 1 mm. The fixing device of this embodiment has the same configuration as the fixing device shown in FIG. 1 except for the heat transfer member 15.

Fixing device of this embodiment (gap L = 1 mm)
Then, in the same fixing device, the temperature rise of the pressure roller was measured when the gap L = 1.5 mm and the gap L = 2.0 mm, and the experiment on the twist of the film was conducted. Figure 9
Is a fixing device similar to the fixing device of the present embodiment.
The gap L between the heat transfer member 15 and L = 1 mm, L = 1.5
mm, L = 2 mm, and when the temperature of the heater 3 was controlled to 160 ° C., an envelope (width 105 ×
Process speed (conveyance speed) of 24 (241 mm)
It is the result of measuring the pressure roller temperature of the paper passing portion and the pressure roller temperature of the non-paper passing portion by thermography when the paper is continuously fed at a distance of 150 mm between mm / sec.

In this experiment, in the fixing device with the gap L = 2 mm, the film is twisted when continuously feeding 25 sheets, and at this time, the temperature difference between the paper passing portion and the non-paper passing portion of the pressure roller is about 100. It was ℃. In the fixing device with the gap L = 1.5 mm, the film begins to be twisted several times during continuous 100 sheet passing,
There was a crisp sound, but it recovered after that.
At this time, the temperature difference between the paper passing portion and the non-paper passing portion of the pressure roller is
It was approximately 95 ° C. In the fixing device of this embodiment with the gap L = 1 mm, the temperature difference of the pressure roller was about 80 ° C. even when 100 sheets were continuously fed, and the film was not twisted. From these things, it is desirable that the gap L between the pressure roller 6 and the heat transfer member 15 be L = 1 mm or less. In consideration of the thermal expansion and mechanical tolerance of the pressure roller, the gap L is used in this embodiment. = 1 mm. Gap L = 1m
Since m is set, the thermal energy accumulated in the non-sheet passing portion of the pressure roller 6 is supplied to the sheet passing portion, and the heat transfer member 15 is used as in the first and second embodiments. It is considered that the effect of heat dissipation was remarkable.

As described above, by using the fixing device of this embodiment, the twisting of the film is prevented, and the twisting of the film causes the fixing failure, the sheet passing failure, and the film being twisted off. The fixing device can be prevented from being damaged. In addition, the temperature rise of the pressure roller in the non-sheet passing area is set to 250 ° C., which is the heat resistant temperature of the fluorine latex coat on the surface layer of the pressure roller.
Since it can be set as follows, it is possible to prevent the pressure roller from being damaged. Further, in the fixing device of this embodiment, since the non-contact heat transfer member is arranged in the pressure roller portion, there is no fear that the durability of the pressure roller is reduced by this.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a sectional view showing a schematic configuration of a tensionless film heating type fixing device as one embodiment of the present invention.

In FIG. 10, reference numeral 1 denotes a horizontally long stay made of heat-resistant resin, which serves as an inner surface guide member for the film 2 described later.

Reference numeral 3 is a heater as a heating element, and the heater 3 is provided along the substantially central portion of the substrate made of alumina or the like.
As the heating element 4, for example, an electric resistance material such as Ag / Pd (silver palladium) is applied to the thickness of 10 μm and the width of 1 to 3 mm by screen printing or the like, and the protective layer 5 is coated with glass or fluororesin. There is.

2 is an endless heat-resistant film,
The stay 1 including the heater 3 is externally fitted. The inner peripheral length of the endless heat-resistant film 2 and the outer peripheral length of the stay 1 including the heater 3 are larger than those of the film 2 by, for example, 3 mm. The length fits loosely with a margin.

The film 2 has a total thickness of 10 in order to reduce the heat capacity and improve the quick start property.
It is possible to use a film of a single layer or a composite layer having a heat resistance, releasability, strength and durability of 0 μm or less, preferably 40 μm or less and 20 μm or more.

Reference numeral 6 denotes a pressure roller as a rotating body which drives the film 2 by forming a fixing nip portion with the heater 3 sandwiching the film 2. The pressure roller 6 has left and right end portions of a central shaft 7 rotatably supported by left and right bearing members (not shown).

In the conventional film heating type fixing device, as the pressure roller, the one in which the central axis is covered with a rubber elastic body having a good releasability such as silicone rubber having a predetermined thickness is used. In such a conventional fixing device, when small-sized paper is continuously fed and the temperature of the non-sheet-passing portion is increased, a thermal expansion of rubber in the axial direction of the pressure roller causes a difference in diameter between the pressure rollers, There was a problem that the film was pushed to one side or twisted in the middle due to the uneven speed of film transport.

To solve this problem, the rubber portion having a large thermal expansion is thinned, and the central shaft made of metal, which has a smaller thermal expansion than the rubber and has a good thermal conductivity, is thickened, so that the axial direction of the pressure roller is increased. It is considered to reduce the nonuniformity of the diameter.

However, when this method is used, the elasticity of the pressure roller is lost, and the fixing nip portion formed by the heater and the pressure roller via the film becomes small,
The heating time for the paper is shortened, which causes a problem of fixing failure.

Therefore, in this embodiment, as shown in FIG. 11, the pressure roller 6 (driving roller) is a central shaft 7 having a diameter of 9 mm.
A 4 mm-thick sponge-made elastic body is wound around the elastic layer 8 a, and a stainless tube 8 b is wound as a transmission layer having a thickness of 0.05 mm on the elastic layer 8 a. The heat-shrinkable tube is coated as the release layer 8c.

The releasing layer 8c improves the releasability of the toner from the surface of the pressure roller, the elastic layer 8a gives the pressure roller elasticity to secure the fixing nip portion, and the transfer layer 8b heats. Is transmitted in the axial direction.

Here, the transfer layer 8b is made of an elastic metal and exhibits better heat transfer as it is closer to the surface layer and thicker, but if it is too thick, it serves as the lower elastic layer 8a. It will interfere.

According to the experiments by the present inventors, the Young's modulus is 1
0 × ¹⁰ 10 N / m ² or more metals, for example, a thickness of 0.
Good results have been obtained with stainless steel or nickel thin films of about 03 to 0.1 mm. Maximum paper size is A
In the four-width fixing device of this embodiment, when the envelopes are continuously fed at 160 ° C., the surface temperature of the pressure roller in the non-sheet-passing portion is about 30 sheets, and the surface temperature of the pressure roller not using the present invention is With the roller, the highest temperature reaches about 250 ° C,
The film 2 is twisted, and if it is further continued, the film 2 is destroyed in the worst case. On the other hand, when the pressure roller 6 of the present embodiment is used, even in the highest temperature portion 210.
The temperature rose only to about 0 ° C., and the film 2 was not broken even if small size paper was continuously fed thereafter. This is because the heat transfer layer transfers the temperature of the non-paper passing portion to the paper passing portion, which lowers the temperature of the non-paper passing portion and raises the temperature of the paper passing portion. This is due to the two effects that the heat generation amount of the heater itself is reduced and the temperature rise of the non-sheet passing portion is also reduced.

Further, the pressure roller of this embodiment is advantageous in that the structure is simple, the manufacture is easy, and the traveling drive of the film 2 is smooth.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIG. The same parts as those of the fourth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 12 shows a cross section of the pressure roller of this embodiment. In this embodiment, unlike the fourth embodiment, the cylindrical thin aluminum shaft 8d is embedded in the elastic body 8a at equal intervals as shown in FIG. To raise.

In this embodiment, the fixing device of Embodiment 4 is used, and the rubber elastic body is made of silicone rubber, and the release layer 8c is made of fluororubber latex in substantially the same size. As the shaft 8d as the heat transfer member, 20 aluminum shafts having a diameter of 1 mm are embedded. Aluminum has very good heat conduction in spite of its lack of elasticity, and when the pressure roller of this embodiment is used, it is possible to obtain an effect substantially equivalent to that of the above embodiment.

Shaft 8 as a heat transfer member of this embodiment
Since d does not require elasticity, it is possible to freely select a material having good heat conduction, and it is possible to secure a certain thickness and to transfer heat very efficiently.

Sixth Embodiment Next, a sixth embodiment of the present invention will be described with reference to FIG. The same parts as those of the fourth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 13 shows a cross section of the pressure roller of this embodiment. In this embodiment, a fixing device similar to that of the fourth embodiment is used, the pressure roller uses silicone rubber for the elastic layer 8a, and the thickness of the heat transfer plate 8e is 0.0 in the elastic layer.
An 8 mm aluminum plate is spirally embedded from the central axis as shown in FIG. By arranging the arcuate plates spirally in this manner, more heat transfer members can be arranged at a position closer to the fixing nip portion formed with the fixing film, and a force is applied in the radial direction. There is an advantage that it is easier to bend and to secure elasticity more easily.

<Seventh Embodiment> Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 14 is a sectional view showing a schematic structure of a film heating type fixing device as one embodiment of the present invention.

In FIG. 14, 1 is a heater 3 which is a heating body.
Is a holder that heat-insulates and also serves as a stay as a reinforcing member of the guide device on the inner surface of the endless film 2.

This holder is made of PPS (polyphenylene sulfide), PAI (polyamide imide), PI.
(Polyimide), PEEK (polyether ether ketone), liquid crystal polymer, or other high heat resistant resin, or a composite material of these resins and ceramics, metal, glass, or the like.

Reference numeral 3 denotes a heater as a heating element, and the heater 3 has a longitudinal direction in a direction orthogonal to the moving direction of the film 2. The substrate 9 is made of a ceramic such as alumina, and the heating resistor 4 is made of an electric resistance material such as Ag / Pd (silver palladium) along the substantially central portion of the lower surface of the heater substrate 9 having a thickness of 10 μm and a width of 1 to 3 mm. Is coated by screen printing or the like, and a glass layer for insulation and protection is provided thereon.

The temperature detecting element 10 is provided on the back surface of the substrate 9.
When the image is heated, the energization of the resistor is controlled so that the temperature detected by the temperature detecting element 10 is maintained at a predetermined set temperature.

2 is an endless heat-resistant film,
It is suspended on the holder 1 including the heater 3. The inner peripheral length of the endless heat-resistant film 2 and the outer peripheral length of the holder 1 including the heater 3 are, for example, 3 mm in the film 2.
Therefore, the film 2 is loosely fitted on the holder 1 including the heater 3 with a sufficient circumferential length.

The film 2 has a total thickness of 10 in order to reduce the heat capacity and improve the quick start property.
It is possible to use a film of a single layer or a composite layer having a heat resistance, releasability, strength and durability of 0 μm or less, preferably 40 μm or less and 20 μm or more.

Reference numeral 6 denotes a pressure roller as a rotating body which forms a nip portion by sandwiching the film 2 with the heater 3.
A central shaft 7 and a roller portion 8 made of a rubber elastic body having a good releasability such as silicone rubber, which is externally mounted on the shaft, and the left and right ends of the central shaft 7 are respectively bearing members (not shown).
The bearing is rotatably supported on the.

The pressure roller 6 is a drive source (not shown).
The film 2 is driven to rotate by the pressure roller 6.

Reference numeral 16 is a film temperature cooling member which is mounted on the holder 1 in the longitudinal direction and absorbs heat of the film 2 in a state of contact with the film 2. The cooling member 16
The film 2 and the film 2 are in contact with each other so as to rub the film 2 lightly to the extent that the cooling member 16 does not apply tension.

The cooling member 16 is made of a metal having a high thermal conductivity in order to easily absorb the heat of the film 2. Specifically, aluminum, zinc, copper, silver or the like can be used.

When several or more small size sheets are continuously passed through the heating device of this structure, the temperature rise in the non-sheet passing portion of the film temperature is suppressed by the cooling member 16 to be lower than the conventional one. At this time, the heat absorbed by the cooling member 16 in the non-sheet passing portion of the film 2 flows to the portion of the cooling member 16 which is in contact with the sheet passing portion of the film 2, and this heat reversely heats the sheet passing portion of the film. In addition, the temperature difference between the non-sheet passing portion and the sheet passing portion of the film is further reduced. That is, the cooling member 16 also has an effect of equalizing the temperature gradient between the non-sheet passing portion and the sheet passing portion of the film.

Here, the cooling effect provided to the film and the reduction of the temperature gradient accompanying it also naturally act on the pressure roller, and in the apparatus having the structure in which the pressure roller also serves as the drive roller as in the present embodiment, the conventional method is used. It is possible to suppress the twisting of the film due to the difference in the feed amount of the film in the longitudinal direction of the pressure roller, which has been a problem.

It is also possible to prevent deterioration of the rubber material used for the pressure roller due to heat. In this embodiment, the cooling member is in contact with the film, but even if it is not in contact, the same effect can be obtained by radiating heat from the film.

<Embodiment 8> Next, an embodiment 8 of the present invention will be described with reference to FIGS. In addition, the same parts as those of the seventh embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 15 is a sectional view showing the schematic arrangement of a film heating type fixing device as an embodiment of the present invention.

Although the cooling member is in contact with the inner surface of the film in the seventh embodiment, it may be in contact with the outer surface of the film as in this embodiment.

In FIG. 15, reference numeral 17 denotes a cooling member pressed against the outer surface of the film, which prevents excessive temperature rise in the non-sheet passing portion of the film and the pressure roller as in the case of the seventh embodiment, and prevents the film length from increasing. This has the effect of leveling the temperature difference in the direction.

Further, by making unevenness on the side of the cooling member 17 which is in contact with the film to increase the surface area,
The heat dissipation from the cooling member is increased to enhance the cooling effect.

Further, when the cooling member 17 is arranged on the outer surface of the film as in this embodiment, the cooling effect of the film is higher than that when it is arranged on the inner surface of the film.

The principle of the cooling action of the film in the present invention is that the heat of the film is taken by the cooling member such as metal, and the cooling of the cooling member itself is left to natural heat dissipation.

Here, when the cooling member is on the inner surface of the film, the space formed inside the film is a relatively closed space with little replacement of air, so the air on the inner surface of the film becomes very hot and the cooling member To the surrounding air is low, and therefore the temperature of the cooling member is also saturated at a high temperature.

On the other hand, when the cooling member is attached to the outer surface of the film, the cooling member can always come into contact with fresh air, so that the saturation temperature becomes low. That is, the temperature of the film can be lowered accordingly.

Further, as shown in FIG. 16, the inner surface of the film,
If the welfare is provided with cooling members on both outer surfaces, unnecessary temperature rise of the film can be prevented, and the temperature gradient in the film longitudinal direction can be reduced.

At this time, in the form in which the cooling members on both the inner and outer surfaces of the film come into contact with the film, the two cooling members sandwich the film, resulting in an increase in the driving torque of the film. Therefore, in this case, it is preferable that either of them is not in contact. Alternatively, PFA, PTFE, F
It may be brought into contact with each other by applying a coating such as EP that reduces the frictional force.

However, the above configuration does not completely deny the contact of the cooling member without coating, but recognizes it as necessary.

<Ninth Embodiment> Next, a ninth embodiment of the present invention will be described with reference to FIG. In addition, the same parts as those of the seventh embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG. 17, the cooling member 18
Is a rotating body and is driven to rotate in accordance with the rotational running of the film.

When the cooling member is rotated in this way, the contact between the cooling member and the film is always made in the portion cooled by heat radiation during one rotation, so that the cooling effect of the film is higher than that of the case where the cooling member is fixed. Get higher.

The rotary cooling member 18 can be used in combination with the cooling member 16 on the inner surface of the film as in the eighth embodiment.

Further, the cooling member on the inner surface of the film can also be a rotating body. Further, the rotary cooling member 18 may be rotationally driven by a gear. In this case, the rotary cooling member can be brought out of contact with the film.

<Embodiment 10> Next, Embodiment 10 of the present invention.
Will be described with reference to FIGS. 18 to 20. FIG. 18 is a sub-sectional view of the film heating apparatus of this embodiment.

In FIG. 18, reference numeral 30 denotes a fixing heater, which is formed by printing a pattern 30b of a resistance heating element that generates heat by energizing silver palladium or the like on a substrate 30a having good thermal conductivity such as alumina.

Reference numeral 51 is a heat-resistant resin such as polyimide molded into an endless belt-like film, and the outer periphery thereof is coated with a fluororesin such as PFA or PTFE in order to improve releasability from the toner. .

Reference numeral 52 denotes a roller for driving the film 51, the surface of which is coated with rubber to increase the friction coefficient.

53 is a tension roller, which is a film 51.
The tension applied to the film is adjusted in the front and back of the drawing by a mechanism (not shown) for preventing the deviation of the film.

Reference numeral P denotes a recording material, which carries an unfixed toner image Ta and is conveyed to the nip N. The unfixed toner image Ta is heated and pressed at the nip portion N and discharged as a fixed image Tb.

Reference numeral 55 is a pressure roller in which fluororubber or silicone rubber is wound around a cored bar.

Reference numeral 81 is an entrance guide for guiding the entrance of the recording material into the nip N.

Numerals 32 and 33 are guide members for guiding the inner surface of the film 51 to stabilize the film running. 32 is located on the inlet side with respect to the recording material traveling direction,
33 is located on the exit side.

FIG. 19 is a perspective view of the guide member 32.
In FIG. 20, the contact surfaces of the guide members 32 and 33 with the film are aligned in the longitudinal direction, and the passing position of the film thereon is also shown at the same time.

As shown in FIGS. 19 and 20, the guide members 32 and 33 are provided with ribs 31 on the guide surfaces of the films along the moving direction of the films indicated by the arrows.
The ribs on the guide member 32 on the inlet side and the ribs on the guide 33 on the outlet side are alternately arranged in the longitudinal position so that they do not overlap.

By guiding the film with the ribs 31, the contact area between the film and the guide member is made to reduce the frictional resistance. At the same time, by alternately arranging the ribs on the inlet side and the outlet side, temperature unevenness due to contact with the ribs of the film can be reduced as compared with the case where the rib positions on the inlet side and the outlet side overlap.

<Embodiment 11> Next, an embodiment 11 of the present invention.
Will be described with reference to FIGS. 21 and 22. FIG. 21 is a sub-sectional view of the film heating apparatus of this embodiment.

In this embodiment, the endless film is suspended with a margin so that the pressure roller 6 can drive the film without applying tension to the film.

In FIG. 21, 1 is a horizontally long stay,
It also serves as an inner surface guide member of the film 2 which will be described later and as a support / reinforcement member for the heater 3 and the heater support 38 which will be described later.

This stay 1 has a horizontally long bottom surface portion 1c and a front wall plate 1a having a transverse cross-section outwardly arcuate curve which is provided by successively standing up from both longitudinal sides of the bottom surface portion 1c.
And a pair of left and right horizontal lugs (not shown) protruding outward from the left and right end portions of the rear wall plate 1b and the bottom surface portion 1c, respectively.

The linear heater 3 as the heating body of the present embodiment has the same structure as that of the tenth embodiment, and has the longitudinal direction in the transverse direction of the fixing film (the direction perpendicular to the running direction of the fixing film 2). It comprises a heater substrate 9 having a heating element 4 integrally attached and supported on the lower surface side of a horizontally long heater supporting body 38 having high rigidity, high heat resistance and heat insulation, along the lower surface longitudinal direction.

The heating element 4 is formed by applying an electric resistance material such as Ag / Pd (silver palladium) to a thickness of about 10 μm and a width of 1 to 3 mm by screen printing along the substantially central portion of the lower surface of the heater substrate 9. Then, a glass layer for insulation and protection is provided thereon.

Further, in order to reduce friction with the fixing film 2, PFA, PTFE or the like may be coated thereon.

The heater support 38 is made of, for example, high heat resistant resin such as PPS (polyphenylene sulfide), PAI (polyamide imide), PI (polyimide), PEEK (polyether ether ketone), liquid crystal polymer, or these resins and ceramics. , A composite material with metal, glass or the like.

2 is an endless heat resistant film,
The stay 1 including the heater 3 and the heater support 38 is externally fitted. The inner peripheral length of the endless heat-resistant film 2 and the outer peripheral length of the stay 1 including the heater 3 and the heater support 38 are larger than those of the film 2 by, for example, 3 mm.
Therefore, the film 2 is loosely fitted around the stay 1 including the heater 3 and the heater support 38 with a sufficient circumferential length.

The film 2 has a total thickness of 10 in order to reduce the heat capacity and improve the quick start property.
It is possible to use a film of a single layer or a composite layer having a heat resistance, releasability, strength and durability of 0 μm or less, preferably 40 μm or less and 20 μm or more.

Reference numeral 6 denotes a pressure roller (pressure contact roller, backup roller) as a rotating body which drives the film by forming a nip portion with the heater 3 sandwiching the film 2, and a central shaft (not shown). And a roller portion made of a rubber elastic body such as silicone rubber having a good releasability, which is externally mounted on the shaft. The left and right end portions of the central shaft are rotatably supported by bearing members (not shown). There is.

The heating device using the tensionless film as described above does not use a driving roller, a tension roller, etc., as compared with the tenth embodiment, so that it has the advantage of being compact and simple, but on the other hand, it cannot be used as the inner surface of the film 2. The heater 3, the guide members 1a and 1b, and the heater support 3 which is a heat insulating member
When the friction with the recording material 8 increases, the film 2 slips between the recording material (not shown) and the toner image on the recording material is dragged.

Therefore, in this embodiment, in order to prevent slippage, a felt 35 for applying a lubricant such as oil or grease is brought into contact with the inner surface of the film, and the inner surface of the film 2 on which oil or the like is attached is a guide member. Ribs 36 and 37 are provided so as not to stick to 1a and 1b. Reference numeral 34 is a member that supports the felt.

The ribs 36 and 37 of the guide portions 1a and 1b have a width of 1 to 3 mm, a height of 0.5 to 1 mm, and an interval of 10 to 20 m.
By setting the thickness to m, the rib-free portion can be moved without contacting the non-rib portion of the guide member due to the rigidity of the film itself.

At this time, as shown in FIG. 22, Example 10 was used.
Similarly to the above, the rib positions are alternately shifted between the inlet side guide 1a and the outlet side guide 1b to suppress the temperature unevenness of the film.

As a result, even in the apparatus in which tension is not applied to the film as in this embodiment, the frictional resistance between the guide and the inner surface of the film can be reduced and the temperature unevenness of the film can be reduced.

<Embodiment 12> Next, Embodiment 12 of the present invention.
Will be described with reference to FIG. The same parts as those of the tenth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 23 shows the inlet side guide member 32 of this embodiment.
And the contact surface of the outlet side guide member 33 with the film 2 are shown with their positions aligned in the longitudinal direction.

The ribs on the guide members 32 and 33 do not have to extend to the full width of the guides, and may be divided into some as shown in FIG. Also in this case, if the positions of the ribs do not overlap between the guides on the inlet side and the outlet side, the effect on the temperature unevenness is greater than that of the tenth embodiment.

<Embodiment 13> Next, Embodiment 13 of the present invention.
Will be described with reference to FIG. The same parts as those of the tenth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 24 shows the contact surface of the guide member 32 with the film 2. As shown in FIG. 24, the guide member 32
The film 2 indicated by the arrow on the guide surface of the film 2
The ribs 31 are provided obliquely at an angle θ of 0 ° or more with respect to the moving direction of.

As described above, by raising the ribs obliquely, the points at which the ribs and the film contact each other in the longitudinal direction during one rotation of the film are increased as compared with the case where the straight ribs are raised. It is possible to further reduce temperature unevenness as compared with.

In this case, if the positions of the ribs are alternately shifted as in the tenth embodiment, a great effect is exerted, but even if the ribs are at the same position in the inlet side guide and the outlet side guide, some effect can be expected. .

Further, this structure can be naturally used in a tensionless film heating apparatus as in the eleventh embodiment.

<Embodiment 14> Next, Embodiment 14 of the present invention.
Will be described with reference to FIGS. 25 and 26. The same parts as those of the tenth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 25 shows the contact surface of the guide member 32 with the film. As shown in FIG. 25, the guide member 32 is provided with ribs 31 on the guide surface of the film 2 at an angle θ with respect to the moving direction of the film 2 shown by the arrow.

Concretely, this angle θ is given by the distance ε between ribs and the rib length ξ in FIG.

[0162]

[Equation 1] ξ sin θ ≧ ε

It satisfies the condition of.

If the ribs are set up as described above, the film always comes into contact with the ribs at any position once during one rotation.

That is, by guiding the film with the ribs 31, the contact area between the film and the guide member is reduced, the frictional resistance can be reduced, and the contact position with the rib in the longitudinal direction of the film can be reduced. Without fixing, temperature unevenness on the film can be prevented.

Needless to say, the ribs do not necessarily have to be aligned in one direction, and the structure shown in FIG. 26 may be used.

Further, this structure can be naturally used in a tensionless film heating type apparatus as in the eleventh embodiment.

Also in this case, the ribs are erected at an angle θ with respect to the traveling direction of the film such that the ribs come into contact with the film at least once during one rotation cycle of the film at all points on the inner surface of the film. I'm good.

<Embodiment 15> Next, Embodiment 15 of the present invention.
Will be described with reference to FIG. The same parts as those of the eleventh embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 27 shows the contact surface of the entrance side film guide member 1a showing the present embodiment with the inner surface of the film.

In this embodiment, the shape of the guide surface on the inlet side is shown in FIG.
The configuration shown in FIG. That is, a plurality of ribs are erected in the film traveling direction, and the portion near the fixing nip of the film guide is formed into a bank shape equal to the height of the ribs in the entire longitudinal direction. However, there is no particular requirement for the rib angle θ, and −90 <θ <90 ° can be obtained.

With this structure, even if the ribs stand at any angle with respect to the film running direction, the temperature unevenness of the film can be leveled by the bank in the vicinity of the fixing nip portion, and the fixing unevenness on the recording material can be prevented. It can be lost.

Further, in this embodiment, the bank-like portion is located near the nib of the inlet side guide, which is the most effective, but it is effective even at another position, and naturally it may be on the outlet side. Alternatively, there may be a plurality.

<Embodiment 16> Next, Embodiment 16 of the present invention.
Will be described with reference to FIG. The same parts as those of the eleventh embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 28 is a contact surface of the entrance side film guide member 1a showing the present embodiment with the inner surface of the film.

In this embodiment, the shape of the guide surface on the inlet side is shown in FIG.
The configuration shown in FIG. That is, a plurality of ribs are erected parallel to the film running direction, and the ribs are cut over the entire longitudinal direction only in the vicinity of the fixing nip of the film guide. The rib angle θ can be −90 ° <θ <90 ° as in the fifteenth embodiment.

With this structure, no matter what angle the rib stands with respect to the running direction of the film, the inner surface of the film is always in contact with the guide in the entire longitudinal region in the vicinity of the fixing nip portion. The temperature unevenness of 1 is evened out here, and the fixing unevenness on the recording material can be eliminated.

[0178]

As described above, according to the first invention of the present application, by providing the contact member or the non-contact heat transfer member to the pressing member, the paper passing portion when the small size paper is continuously passed is provided. It is possible to reduce the temperature difference in the non-sheet passing portion and prevent the device from being damaged due to the temperature rise in the non-sheet passing portion.

Further, according to the second invention of the present application, by providing the heat transfer member to the pressing member, the speed of heat conduction in the pressing member in the direction perpendicular to the recording material advancing direction is increased, and the non-sheet passing portion is provided. By transmitting the rise in temperature of the pressure member to the paper-passing portion, the temperature rise in the non-paper-passing portion at the time of continuously heating the small-sized recording material is mitigated, and the film width direction displacement and It is possible to prevent wrinkles and reduce high-temperature offset when a large-sized recording material is passed immediately after continuous heating of a small-sized recording material.

Further, according to the third and fourth inventions of the present application,
By placing a cooling member with a relatively high heat capacity such as metal and good thermal conductivity on the fixing film in the vicinity of the film in a non-contact manner or in contact therewith, a non-paper passing portion when continuously passing small size paper It is possible to suppress excessive temperature rise, and to prevent twisting of the fixing film, heat deterioration of the pressure roller rubber material, hot offset, and the like due to it.

According to the fifth to seventh inventions of the present application,
In a film heating type heating device having a film guide with ribs, the rib or the guide surface and the film are brought into uniform contact with each other as the film moves, so that the contact area between the guide member and the film is not increased,
It is possible to prevent uneven temperature on the film surface.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a sheet passing portion and a sheet non-passing portion in the apparatus shown in FIG.

FIG. 3 is a cross-sectional view of a heat fixing device used for comparison with the present invention in Example 1 of the present invention.

FIG. 4 is a diagram showing a pressure roller temperature when a small-sized recording material is continuously fed using the apparatus of FIG.

5 is a diagram showing a temperature of a pressure roller when a small-sized recording material is continuously fed using the apparatus of FIG.

FIG. 6 is a cross-sectional view illustrating a schematic configuration of a heat fixing device according to a second exemplary embodiment of the present invention.

FIG. 7 is a diagram showing a pressure roller temperature when a small-sized recording material is continuously fed using the apparatus of FIG.

FIG. 8 is a cross-sectional view illustrating a schematic configuration of a heat fixing device according to a third exemplary embodiment of the present invention.

9 is a diagram showing a temperature of a pressure roller when a small-sized recording material is continuously fed using the apparatus of FIG.

FIG. 10 is a cross-sectional view of a heat fixing device according to a fourth embodiment of the present invention.

11 is a sectional view of a pressure roller of the apparatus shown in FIG.

FIG. 12 is a cross-sectional view of a pressure roller according to a fifth exemplary embodiment of the present invention.

FIG. 13 is a sectional view of a pressure roller according to a sixth embodiment of the present invention.

FIG. 14 is a sectional view showing a schematic configuration of a fixing device according to a seventh embodiment of the present invention.

FIG. 15 is a sectional view showing a schematic configuration of a fixing device according to an eighth embodiment of the present invention.

FIG. 16 is a sectional view showing a schematic configuration of another fixing device according to Embodiment 8 of the present invention.

FIG. 17 is a sectional view showing a schematic configuration of a fixing device according to a ninth embodiment of the present invention.

FIG. 18 is a sectional view showing a schematic configuration of a fixing device according to a tenth embodiment of the invention.

FIG. 19 is a perspective view showing a schematic configuration of a guide member in the apparatus shown in FIG.

20 is a view showing the arrangement of ribs of the guide member in the apparatus shown in FIG.

FIG. 21 is a sectional view showing a schematic configuration of a fixing device according to an eleventh embodiment of the present invention.

22 is a view showing the arrangement of ribs of the guide member in the apparatus shown in FIG. 21.

FIG. 23 is a diagram showing an arrangement of ribs of a guide member according to a twelfth embodiment of the present invention.

FIG. 24 is a diagram showing an arrangement of ribs of a guide member according to a thirteenth embodiment of the present invention.

FIG. 25 is a diagram showing an arrangement of ribs of a guide member in Embodiment 14 of the present invention.

FIG. 26 is a diagram showing another arrangement of ribs of the guide member according to the fourteenth embodiment of the present invention.

FIG. 27 is a diagram showing another arrangement of ribs of the guide member according to the fifteenth embodiment of the present invention.

FIG. 28 is a diagram showing another arrangement of ribs of the guide member according to the sixteenth embodiment of the present invention.

FIG. 29 is a sectional view showing a schematic configuration of a conventional heat fixing device.

FIG. 30 is a cross-sectional view showing a schematic configuration of another conventional heat fixing device.

[Explanation of symbols]

 1 stay, holder (support) 1a, 1b guide member 2 film 3 heater (heating body) 6 pressure roller (pressure member) 8b, 8d, 8e heat transfer member 12, 14, 15 heat transfer member 16, 17, 18 Cooling Member 30 Heater (Heating Body) 31 Rib 32, 33 Guide Member 36, 37 Rib 51 Film 55 Pressure Roller (Pressure Member) P Recording Material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuza Yo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (15)

[Claims] 1. A support for supporting a heating body, an endlessly movable film stretched so as to contact the heating body and the support, and a film arranged to be pressed against the heating body through the film. In the heating device for applying the thermal energy of the heating body to the recording material by sandwiching and conveying the recording material at the pressure contact portion, a heat transfer member is arranged around the pressing member. A heating device characterized by being installed. 2. The heating device according to claim 1, wherein the heat transfer member is arranged so as to contact the pressure member. 3. The heating device according to claim 1, wherein the heat transfer member is arranged so as to be in non-contact with the pressing member with a predetermined gap. 4. A support for supporting a heating body, an endlessly movable film stretched so as to come into contact with the heating body and the support, and arranged so as to come into pressure contact with the heating body through the film. A heating device for applying the thermal energy of the heating element to the recording material by sandwiching and transporting the recording material at the pressure contact portion. The heating device is provided with a heat transfer member formed so as to extend in a direction perpendicular to the traveling direction. 5. The pressurizing member is formed in a roller shape, and the heat transfer member is a cylindrical elastic body disposed on the surface layer of the pressurizing member or in the vicinity thereof. The heating device according to. 6. The heating device according to claim 4, wherein the pressing member has a layer having elasticity, and the plurality of heat transfer members are movably arranged inside the layer. . 7. A support for supporting the heating body, an endlessly movable film stretched so as to contact the heating body and the support, and a film provided so as to be in pressure contact with the heating body through the film. In a heating device for applying thermal energy of the heating element to the recording material by sandwiching and conveying the recording material at the pressure contact portion, a cooling member having good thermal conductivity and a large heat capacity is provided. The heating device is arranged so as to come into contact with the film over the longitudinal direction of the film. 8. A support for supporting a heating body, an endlessly movable film stretched so as to contact the heating body and the support, and a film arranged to be in pressure contact with the heating body through the film. In a heating device for applying thermal energy of the heating element to the recording material by sandwiching and conveying the recording material at the pressure contact portion, a cooling member having good thermal conductivity and a large heat capacity is provided. A heating device, which is arranged so as to be in non-contact with the film in the vicinity of the film in the longitudinal direction thereof. 9. The heating device according to claim 7, wherein the cooling member is made of metal. 10. A heating body supported by a support body, an endlessly movable film stretched so as to come into contact with the heating body, a guide member having a plurality of ribs in contact with the film, and a film interposed therebetween. And a heating member arranged so as to be pressed against the heating body, and the recording material is sandwiched and conveyed at the pressing portion to impart the thermal energy of the heating body to the recording material, The guide member is disposed on the upstream side and the downstream side in the moving direction of the film around the heating body, and the plurality of ribs extend parallel to the moving direction of the film, and the moving direction The heating device is arranged so that the position in the direction orthogonal to the above does not overlap on the upstream side and the downstream side. 11. A heating body supported by a support body, an endlessly movable film stretched so as to be in contact with the heating body, a guide member having a plurality of ribs in contact with the film, and a film interposed therebetween. And a heating member arranged so as to be pressed against the heating body, and the recording material is sandwiched and conveyed at the pressing portion to impart the thermal energy of the heating body to the recording material, The heating device, wherein the plurality of ribs are arranged at a predetermined angle with respect to the moving direction of the film. 12. The rib has a distance ξsi when the distance between the ribs is ε and the length of the rib is ξ with respect to the moving direction of the film.
The heating device according to claim 11, wherein the heating device has an angle θ that satisfies the relationship of n θ ≧ ε. 13. A heating body supported by a support body, an endlessly movable film stretched so as to be in contact with the heating body, a guide member having a plurality of ribs in contact with the film, and a film interposed therebetween. And a heating member arranged so as to be pressed against the heating body, and the recording material is sandwiched and conveyed at the pressing portion to impart the thermal energy of the heating body to the recording material, The guide member is provided at least on the upstream side in the moving direction of the film with respect to the heating body, and the height of the guide surface on the heating body side is equal over the entire area in the direction orthogonal to the moving direction. A heating device characterized in that it is formed in. 14. The height of the guide surface on the heating body side is formed to be equal to the height of the rib over the entire area in the direction orthogonal to the moving direction of the film.
The heating device according to item 3. 15. The heating device according to claim 13, wherein the guide surface on the heating body side is not provided with ribs.