JPH075784A - Heater and image forming device - Google Patents

Abstract

PURPOSE:To moderate or to prevent the occurrence of a temp. rise at a non-paper passing part and to eliminate various kinds of troubles due to the temp. rise at the non-paper passing part and the trouble due to the thermal expansion of a pressure member by applying elasticity to a heating body and forming a press-contact nip part having a prescribed width between the pressure member and the heating body by the elastic deformation of the heating body. CONSTITUTION:As to the heater 1 of a heat roller system and a film heating system, etc., which heats a material to be recorded 8 at the press-contact nip N formed between the heating body 1 and the pressure member 2, the elasticity is applied to the heating body 1 so as to form the press-contact nip part N having a prescribed width between the pressure member 2 by the elastic deformation of the heating body 1. Then, a rigid material provided with good thermal conductivity and whose thermal expansion is extremely reduced and having accuracy in outer dimension is used as the pressure member 2. Thus, the thermal conductivity of the press-contact nip part N formed between the heating body 1 and the pressure member 2 along the longitudinal direction is increased, so that the heat generated in the non-paper passing area is easily diffused into a paper passing area and the excessive temp. rise due to the heat accumulation in the non-paper passing area is suppressed, so that the temp. rise phenomenon is moderated or prevented at the non-paper passing part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for heating a material to be heated at a pressure nip portion between a heating body and a pressing member, and an image forming apparatus provided with the heating device as a heat fixing device.

[0002]

2. Description of the Related Art As a specific example of a heating device for heating a material to be heated in a pressure contact nip portion between a heating body and a pressure member, in an image forming apparatus such as an electrophotographic printer, an electrophotographic copying machine, an electrostatic recording device, There is a heat roller type image heating and fixing device.

This is basically composed of a heating roller (fixing roller) as a heating body and a pressure roller as a pressure member pressed against the heating roller. The pair of rollers are rotated to press the roller pair. Introducing a recording material (transfer material sheet, electrostatic recording paper, electro-fax paper, printing paper, etc.) as a heated material on which an unfixed image (toner image) is formed and carried in the nip portion (fixing nip portion) By sandwiching and passing the pressure contact nip portion, the unfixed image is heat-pressure fixed as a permanently fixed image on the surface of the recording material by the heat of the heating roller and the pressing force of the pressure contact nip portion.

In the heat roller system, when the heating roller is a surface heat generation type roller, the energy efficiency is high, the surface temperature rises quickly, and the temperature can be rapidly raised from room temperature to a fixable temperature at the time of printing. It is an energy-saving type device that can reduce power consumption to zero.

A film heating type device has been put into practical use as another energy-saving type heating device or an image heating and fixing device. This is disclosed in, for example, JP-A-63-31
3182, JP-A-2-157878, 4-440
75-44083, 4-204980-204984, etc., a heat-resistant film (fixing film) is closely adhered to a heating element with a pressure member and slid and conveyed, and the heating element is sandwiched between the heating elements. A heat-resistant film is introduced between the heat-resistant film and the pressure member in the pressure-contact nip part formed by the pressure member and the heat-resistant film, and the pressure-contact nip part is conveyed along with the heat-resistant film to resist heat from the heating element. It is a device for applying to a material to be heated through a flexible film.

In the film heating type heating device, since a low heating capacity linear heating element can be used as a heating element and a thin film having a low heating capacity can be used, power saving and reduction of wait time (quick start property) can be achieved. In addition, it is possible to suppress the temperature rise inside the apparatus, and in the image heating and fixing device, the fixing point and the separation point can be set separately, so that there is an advantage that offset can be prevented.

[0007]

SUMMARY OF THE INVENTION A heating device for heating a material to be heated in a pressure contact nip portion between a heating body and a pressing member, such as the above-mentioned heating roller system or film heating system, has hitherto been used. Was used as an elastic roller made of heat resistant rubber or the like to form a pressure contact nip portion having a predetermined width with the heating body by elastic deformation of the pressure elastic roller.

However, the elastic roller made of heat-resistant rubber or the like as the pressing member has a poor thermal conductivity and a large coefficient of thermal expansion. Therefore, there were the following problems.

[0009]. In a heating device of a heat roller type or a film heating type, a material to be heated having a width smaller than the material to be heated (small-sized material to be heated) continuously introduced into the apparatus is continuously introduced and heat-treated. As a result, the heating body portion of the pressure contact nip portion formed between the heating body and the pressure member, which corresponds to the area through which the material to be heated passes (paper passing area), is covered by the temperature control system. While the heat consumption for heating the heating material is compensated and maintained at a predetermined temperature, the heating element portion corresponding to the area where the heating material does not pass (non-sheet passing area) is Since heat is not consumed for heating, heat is stored, and the heating element part / pressurizing member part corresponding to this non-paper passing area,
In the case of a film heating type heating device, the temperature of the heating element, heat-resistant film, and pressure member rises above the paper-passing area that is maintained and maintained at a specified temperature. The "part temperature increase" phenomenon occurs, but the poor thermal conductivity of the elastic roller made of heat-resistant rubber or the like as the pressing member is one of the major causes of promoting this non-sheet passing part temperature increase phenomenon.

In particular, in a heating device of a heating roller type using a heating roller of a surface heating type or a heating device of a film heating type, the heat conduction in the longitudinal direction of the pressure contact nip portion of the pressure member (fixing roller, fixing film) is poor. For this reason, the temperature rise in the non-sheet passing portion becomes large, and thermal damage easily occurs to the parts near the heating member, such as the pressure elastic roller and the bearing.

[0011]. If the temperature rise of this non-sheet-passing portion rises significantly, the temperature of the non-sheet-passing portion rises next time when a large-sized material to be heated is passed than the small-sized material to be passed. The heating temperature of the heated material portion corresponding to the pressure contact nip portion becomes higher than that of the other heated material portions, causing uneven heating.

If the material to be heated is a recording material that supports an unfixed developer image to which an image is to be fixed, uneven fixing, gloss unevenness, toner offset and the like of the image will occur.

In a film heating type heating device, when heat resistant grease is interposed as a lubricant between the heating body and the film in order to reduce the sliding frictional resistance between the heating body and the film, the grease is overheated to raise the temperature at the non-sheet passing portion. At the same time, the film is evaporated to cause poor film conveyance, and the film life is shortened.

.. Further, due to the large coefficient of thermal expansion of an elastic roller such as heat-resistant rubber as a heating member, the roller outside diameter of the roller in the sheet passing area and the roller outside diameter of the roller in the sheet non-passing area are increased due to the temperature rise in the sheet non-passing area. There is a problem that an abnormal image such as paper wrinkles occurs when a large-sized material to be heated is passed in this state.

.. Further, in the case of a device in which the pressure elastic roller is a drive roller that conveys the material to be heated or the heat resistant film, the conveying speed of the material to be heated or the heat resistant film is determined by the peripheral speed of the drive roller. If the coefficient of thermal expansion of the pressure elastic roller is large, the peripheral speed tends to change,
For example, in the case of the image heating fixing device of the image forming apparatus, when the recording material is stretched between the image forming portion such as the image transfer portion and the image heating fixing device, the recording material is pulled by the image heating fixing device. Then, the formed image stretches or the image blurs.

Therefore, the present invention alleviates or prevents the temperature rise in the non-sheet-passing portion to eliminate the above-mentioned problems caused by the temperature rise in the non-sheet-passing portion, and the thermal expansion of the pressing member. The purpose is to solve the problems caused by it.

[0017]

The present invention is a heating device and an image forming apparatus characterized by the following configurations.

(1) A heating device for heating a material to be heated in a pressure contact nip portion between a heating body and a pressing member, wherein the heating body is provided with elasticity and elastically deformed to the pressing member. A heating device characterized in that a pressure contact nip portion having a predetermined width is formed therebetween.

(2) A heat-resistant film is adhered to a heating member by a pressure member and slidably conveyed, and a heat-resistant film in a pressure contact nip portion formed between the heating member and the pressure member with the heat-resistant film sandwiched therebetween. The material to be heated is introduced between the pressure member and the pressure member, and the heat of the heating element is conveyed through the pressure contact nip part together with the heat resistant film to apply the heat of the heating element to the material to be heated through the heat resistant film. A heating device, wherein a heating body is provided with elasticity, and a heat-resistant film is sandwiched between the heating member and a pressing member by elastic deformation of the heating body to form a pressure contact nip portion with a predetermined width. .

(3) The heating device according to (1) or (2), wherein the pressure member is a rigid body.

(4) The heating device according to (1) or (2), wherein the pressing member is a good heat conductor.

(5) The heating device according to (1) or (2), wherein the pressure member is a rotating body.

(6) The heating device according to (1), wherein the heating element is a surface-heating type rotating element having elasticity.

(7) The heating according to any one of (1) to (6), wherein the material to be heated is a recording material that supports a visible image and is a heat fixing device that heats the visible image. apparatus.

(8) An image forming apparatus comprising the heating device according to any one of (1) to (7) as a heat fixing device for heating a visible image on a recording material.

[0026]

The heating member is provided with elasticity, and by the elastic deformation of the heating member, a press contact nip portion having a predetermined width is formed between the heating member and the pressing member, so that the pressing member has good thermal conductivity. In addition, it is possible to use a rigid member that has very little thermal expansion and good outer diameter accuracy.

As a result, the thermal conductivity along the longitudinal direction of the pressure contact nip portion between the heating member and the pressing member is increased, so that the heat in the non-sheet passing area easily diffuses into the non-sheet passing area. Excessive temperature rise due to heat storage is suppressed, and the temperature rise phenomenon of the non-sheet passing portion is alleviated or prevented.

Therefore, due to the temperature rise in the non-sheet passing portion, heat damage to parts such as bearings in the vicinity of the heating member, and abnormal images such as uneven heat fixing, uneven gloss, and offset of the image of the recording material as the heating material. Also, the generation of paper wrinkles is eliminated.

Since the heating element has elasticity,
The surface of the heating body having elasticity adheres to the surface of the recording material as the material to be heated introduced into the pressure contact nip portion along the surface of the recording material due to elastic deformation of the heating body to form a visible image. Since the heat conduction is performed, the thermal efficiency is improved, and since the visible image is also wrapped, the fixing property is improved, and at the same time, the occurrence of electrostatic offset can be reduced.

Also, when the pressing member is a driving rotating body for conveying the material to be heated or a film in a film heating type heating device, the peripheral speed due to thermal expansion is small and the recording material or the film is easily conveyed. -The conveyance speed is stable, and it is possible to prevent the image from being stretched or blurred due to the recording material being pulled.

[0031]

【Example】

<Embodiment 1> (FIGS. 1 to 3) The heating device of this embodiment is a heat roller type image heating and fixing device using a surface heating type heating roller. FIG. 1 is a schematic cross-sectional view of a main part of the apparatus, and FIG. 2 is a schematic vertical cross-sectional view of one end side of a heating roller.

Reference numeral 1 denotes a surface-heating type heating roller (fixing roller) having elasticity as a heating element, and 2 a pressure roller as a pressure member. Both rollers 1 and 2 are arranged vertically in parallel. They are arranged and pressed against each other with a predetermined pressing force.

N is a pressure contact nip portion (fixing nip portion) formed between the rollers 1 and 2 by elastic deformation of the heating roller 1 by pressure contact between the rollers 1 and 2. The heating roller 1 is rotationally driven by the driving means M in the clockwise direction a as indicated by the arrow, and the pressure roller 2 is driven to rotate.

In the heating roller 1, a heat insulating layer 1b made of a heat resistant heat insulating material and an elastic heat generating layer 1c are sequentially formed on a core material 1a, and a heat-resistant release layer for preventing contamination of the surface of the heating roller on the outermost layer. 1d is covered.

The core material 1a is used to obtain the strength of the heating roller 1, and may be formed by processing aluminum or stainless steel into a cylindrical shape or a hollow cylindrical shape.

In the heat insulating layer 1b, the heat generated by the heat generating layer 1c in order to accelerate the temperature rise of the heating roller 1 is applied to the core material 1.
It is provided so as not to escape to the a side. Heat insulation layer 1
As the heat-resistant heat insulating material constituting b, heat-resistant materials such as nylon 6, nylon 66, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide mixed with about 30-40% of heat-resistant reinforcing fibers such as short glass fibers are used. A reinforced resin, a heat-resistant polymer such as a silicone resin, a fluororesin, a polyimide, an aromatic polyamide, or a polybenzimidazole, or an inorganic solid heat insulating material such as foam glass may be used.

As the resistance heating elastic body constituting the elastic heating layer 1c, a conductive filler such as carbon black is added to a resin such as silicon rubber or fluororubber so that the volume resistivity is 1 × 10 ^-1 Ωcm or less. A set heat resistant conductive elastic body or the like can be used.

As the heat-resistant release layer 1d, PFA or PTF is used.
A fluororesin such as E can be used. It is desirable that the thickness of the heat-resistant release layer 1d be 20 μm or less so as not to hinder the heat conduction from the heat generating layer 1c to the recording material 8 as the material to be heated introduced into the pressure contact nip portion N.

As shown in FIG. 2, energizing electrodes 1e are attached to both ends of the elastic heating layer 1c of the heating roller 1, and the elastic heating layer 1c is energized through the electrodes 1e to heat it. The surface of the roller 1 is heated.

The pressure roller 2 has a PF as a heat-resistant release layer 2b on a hollow cylindrical good heat-conductive core material 2a made of a metal having high heat conductivity such as aluminum or copper, or alumina.
A, a fluororesin such as PTFE, or a fluororubber / fluororesin mixed latex coated with a thickness of 10 to 50 μm may be used.

Further, in order to increase the nip width of the pressure contact nip portion N, a pressure roller structure may be used in which a heat-resistant thin rubber 2c is coated on a good heat conductive core material 2a as shown in FIG. At this time, the thickness of the thin rubber 2c is the pressure roller 2
1 mm or less, preferably 0.5 mm or less so as not to reduce the thermal conductivity of the surface of the. Further, a heat-resistant release layer 2b may be provided on the thin rubber layer 2c.

Thus, the roller pair 1 and 2 of the heating roller 1 and the pressure roller 2 are rotationally driven to energize the heat generating layer 1c of the heating roller 1 to generate heat, thereby making the surface temperature of the heating roller 1 predetermined. By raising the temperature to the fixing temperature and introducing the recording material 8 on which the unfixed visible image T is formed and carried to the pressure contact nip portion N, the recording material 8 is conveyed while sandwiching the pressure contact nip portion N,
The unfixed visible image T is heat-pressure fixed on the surface of the recording material 8 by the heat of the heating roller 1 and the pressure of the pressure contact nip portion N.

Since the heating roller 1 of the apparatus of the present embodiment is of the surface heating type, it has high energy efficiency, and when the heating layer 1c is energized, the surface temperature rises quickly and the temperature can be raised quickly from room temperature to the fixable temperature during printing. Therefore, the power consumption during standby can be reduced to zero and energy can be saved.

During printing, the surface temperature of the heating roller 1 is detected by a temperature detecting element (not shown), and the heating layer 1c is not energized so that the detected temperature of the element is maintained at a predetermined fixing temperature. It is controlled by the energization control circuit.

A) Since the heating roller 1 is provided with elasticity and the heating roller 1 is elastically deformed to form a pressure contact nip portion N with a predetermined width between the heating roller 1 and the pressure roller 2, the pressure roller 2
As a result, it is possible to use a good heat conductor made of a rigid body.

As a result, the thermal conductivity along the longitudinal direction of the pressure contact nip portion between the heating roller 1 and the pressure roller 2 is increased, so that the heat in the non-sheet passing area easily diffuses to the sheet passing area. Excessive temperature rise due to heat storage in the area is suppressed, and the temperature rise in the non-sheet passing portion is alleviated or prevented.

B) Therefore, heat damage to parts such as bearings in the vicinity of the heating member due to temperature rise in the non-sheet passing portion is prevented.

C) Abnormal images such as uneven heat fixing, uneven gloss, and offset of the image on the recording material due to the temperature rise in the non-sheet passing portion, and the occurrence of paper wrinkles are eliminated.

D) Since the heating roller 1 has elasticity, the surface of the heating roller 1 is elastically deformed on the surface of the recording material 8 introduced into the pressure contact nip portion N by the elastic deformation of the recording material. Since heat is conducted to the visible image (toner image) by closely adhering along the surface, the thermal efficiency is improved, and since it also has the effect of wrapping the visible image, at the same time the fixing property becomes good and
It is also possible to reduce the occurrence of electrostatic offset.

E) The pressure roller 2 is not an elastic roller such as a heat resistant rubber having a high thermal expansion coefficient and a high thermal expansion coefficient, but has a good thermal conductivity and an extremely small thermal expansion coefficient. Since a rigid roller with high accuracy can be used, heating due to a large thermal expansion difference between the roller outer diameter of the paper passing area and the roller outer diameter of the paper non-passing area due to the temperature rise of the non-paper passing area The occurrence of abnormal images such as paper wrinkles on the material is prevented.

F) Further, when the pressure roller is used as a driving roller for the material to be heated, the peripheral speed change due to thermal expansion is small and the expansion or blurring of the image due to the tension of the recording material is prevented. It

Example 2 (FIG. 4) In Example 1 described above, the heat generating layer 1c on the surface of the heating roller 1 itself was made to have elasticity, but in this Example, the thickness is 30 to 30 mm.
The heating layer 1g of 50 μm and the elastic layer 1f together with the pressure roller 2
The same effect as that of the above-described first embodiment is provided by pressing it against.

That is, as shown in FIG. 4, the heating roller 1 of this embodiment has a heat insulating layer 1b made of a heat resistant heat insulating material and an elastic layer 1f made of a heat resistant elastic body on a core material 1a made of aluminum, stainless steel or the like. Formed, thickness 30-50 μm on it
The following heat generating layer 1g is adhered, and the heat-resistant release layer 1d is coated on the outermost layer.

The elastic layer 1f is made of silicone rubber, fluororubber or the like.

The heating layer 1g is made of, for example, PFA, PTFE,
Fluorine resin such as EPE, heat resistant resin such as polyimide, etc. are formed into a film on a heater base material, and an electric resistance material such as Ag / Pd is formed by screen printing to a thickness of about 10 μm.
It is a film-shaped heating element coated to have a thickness of about m.

An electrode (not shown) is attached to the heat generating layer 1g, and electricity is supplied through the electrode to heat the surface of the heating roller.

The heating roller 2 is a good heat conductor roller having the same structure as that of the first embodiment.

In this embodiment, the heating roller 1 and the pressure roller 2
The pressure contact nip portion N is formed by the elasticity of the elastic layer 1f of the heating roller 1, and the pressure roller 2 is made of a good heat conductor as in the first embodiment, so that the heat conductivity in the longitudinal direction of the apparatus can be improved. Have secured.

Therefore, also in the case of the apparatus of this embodiment, the same effects as the above a) to f) are obtained as in the case of the apparatus of the first embodiment.

Further, since heat generation and elasticity of the pressure roller 1 are functionally separated by the heat generating layer 1g and the elastic layer 1f, a material that can be used as a material for forming the surface heat generating layer 1g and a material for forming the elastic layer 1f is selected. The breadth of.

Further, in the surface heating layer 1f as in this embodiment, the distribution of heat distribution in the longitudinal direction of the heating roller can be easily adjusted,
If it is combined with the good heat conductive pressure roller 2, more reliable fixing temperature control becomes possible.

<Embodiment 3> (FIGS. 5 and 6) This embodiment is a film heating type heating device (image heating and fixing device). The apparatus of this example is disclosed in JP-A-4-44075.
~ 44083 gazette, the same 4-204980-20498.
This is a so-called tensionless type film heating system device disclosed in Japanese Patent Publication No. 4 or the like. FIG. 5 is a cross-sectional view of a main part of the apparatus, and FIG. 6 is an enlarged view of a pressure contact nip portion.

Reference numeral 7 designates a gutter-shaped film inner surface guide stay having a substantially semi-circular cross section, and a linear heating of elastic low heat capacity, which will be described later, is formed in a groove formed along the length of the outer lower surface of the stay. The body 5 is inserted and fixedly supported.

The stay 7 includes PPS (polyphenylene sulfide), PAI (polyamide imide), PI (polyimide), PEEK (polyether ether ketone),
It can be made of a highly heat-resistant resin such as liquid crystal polymer or a composite material of these resins and ceramics, metal, glass or the like.

Reference numeral 6 is a cylindrical heat-resistant film, which is externally fitted to the stay 7 including the heating body 5. The inner peripheral length of the cylindrical film 6 and the outer peripheral length of the stay 7 including the heating body 5 are larger than those of the film 6 by, for example, about 3 mm. The length fits loosely with a margin.

The film 6 has a film thickness of 100 in order to reduce the heat capacity and improve the quick start property.
It is possible to use a single layer or a composite layer film having a heat resistance, releasability, strength, durability and flexibility of not more than 60 μm, preferably not more than 60 μm and not less than 20 μm.

For example, a single layer film such as PTFE, PFA, FEP, or polyimide, polyamide imide, P
PT on the outer peripheral surface of EEK, PES, PPS, etc. films
It is a composite layer film coated with a release layer such as FE, PFA and FEP.

The pressure roller 2 is a good thermal conductor roller similar to that of the first and second embodiments, and the film 6 is sandwiched with a predetermined pressing force by a bearing means and an urging means (not shown) so that the heating body 5 is heated. A pressure contact nip portion N is formed by being disposed in pressure contact with the surface.

The pressure roller 2 is rotationally driven in the counterclockwise direction indicated by an arrow by transmitting a rotational driving force by a driving means M through a power transmission system (not shown).

Due to the frictional force between the pressure roller 2 and the outer surface of the film due to the rotational driving of the pressure roller 2, the rotational force acts directly on the film 6 (when the recording material 8 is introduced into the pressure contact nip portion N, the recording material 8 is exposed). A rotational force acts indirectly on the film 6 via the recording material 8), and the film 6 is rotationally driven in the clockwise direction a as indicated by an arrow while sliding in pressure contact with the surface of the heating body 5. The film inner surface guide stay 7 facilitates rotation of the film 6. Further, in order to reduce the sliding resistance between the inner surface of the film 6 and the surface of the heating body 5, it is preferable to interpose a small amount of a lubricant such as heat resistant grease between them.

When the rotational peripheral speed of the film 6 is stabilized by the rotation of the pressure roller 2 and the temperature of the heating body 5 rises to a predetermined level, the film 6 is sandwiched between the heating body 5 and the pressure roller 2. The recording material 8 to be image-fixed as the material to be heated is introduced between the film 6 in the pressure contact nip portion N and the pressure roller 2 and is conveyed while sandwiching the pressure contact nip portion N together with the film 6. The heat of the heating body 5 is applied to the recording material 8 via the film 6, and the unfixed visible image T on the recording material 8 is heat-fixed on the surface of the recording material 8. The recording material 8 passing through the pressure nip portion N is separated from the surface of the film 6 and conveyed.

In the tensionless type film heating type apparatus of this embodiment, the pressure contact nip portion N and the film inner surface guide stay outer surface portion on the upstream side of the pressure contact nip portion N in the film rotation direction and the film when the film is rotationally driven. Tension acts only on the film part in the contact area,
Tension does not act on most of the rest of the film.

Therefore, the displacement force of the film 6 along the length of the stay in the film rotational driving state is small, and the film displacement control means or the film displacement control means can be simplified. For example, the film shift control means may be as simple as a flange member 9 that receives the film end portion, and the film shift control means may be omitted to reduce the cost and size of the apparatus.

The heating element 5 has the layer structure shown in FIG.
The heat generating films 5a to 5c are adhered to the heater support 5e via the heat resistant elastic layer 5d, and are elongated in a direction perpendicular to the transport direction a of the film 6 or the recording material 8.

The heat generating films 5a to 5c are made of PEA, PT.
A heating layer 5b and a heating element protective layer 5c are sequentially formed on a heater base material 5a formed into a film shape of a fluororesin such as FE, FEP, and EPE or a heat resistant resin such as polyimide.

The heat generating layer 5b is formed along the length of the surface of the heater substrate 5a, for example, Ag / Pd (silver palladium), Ru.
It is formed by applying an electric resistance material such as O ₂ or Ta ₂ N in a linear or strip shape having a thickness of about 10 μm and a width of 1 to 3 mm by screen printing or the like.

The heat resistant elastic layer 5d is made of silicone rubber, fluororubber or the like.

The heater support 5e is a high heat resistant resin, a composite material of these resins and ceramics, metal, glass or the like.

On the heating element protective layer 5c of the heating element 5, in order to further reduce friction with the inner surface of the film 6, PFA, P
A heat-resistant release layer such as TFE may be coated.

The heating element 5 has elasticity including the elastic layer 5d, and is elastically deformed as shown in FIG. 6 so that the film 6 is sandwiched between the heating element 5 and the pressure roller 2 which is a good heat conductor. A press contact nip portion N having a width is formed.

Therefore, also in the case of the film heating type heating apparatus of this embodiment, the same effects as those of the apparatus a) to f) of the above-mentioned embodiment 1 are obtained.

Further, since the heat generating layer 5b as in this embodiment can adjust the heat distribution distribution in the longitudinal direction of the heating body, a more reliable fixing temperature control can be performed by combining with the good heat conductive pressure roller 2. become.

Further, since the pressure roller has a good outer diameter accuracy and an extremely small thermal expansion, the film 6 as in this embodiment is used.
In a device that conveys the recording material 8 or the recording material 8 by driving the pressure roller 2, the conveyance properties of the film 6 and the recording material 8 are improved.

<Embodiment 4> (FIGS. 7 to 9) FIGS. 7 to 9 show other examples of the configuration of a film heating type heating device.

In FIG. 7, the first film suspending roller 11, the second film suspending roller 12, and the heating element 5 held by the heat insulating holder 10 are arranged in parallel with each other by three members 11.
An endless belt-shaped heat-resistant film 6 is stretched between 12 and 5, and the pressure roller 2 is disposed by pressing the heat-resistant film 6 against the heating body 5 with the film 6 interposed therebetween. The film suspension roller 11 or the pressure roller 2 of FIG.
When the first film suspension roller 11 is used as a drive roller, the pressure roller 2 is driven to rotate.

In FIG. 8, an endless belt-shaped heat-resistant film 6 is suspended and stretched between the heating member 5 and two members 5 and 14 of one film suspension roller 14, and the film 6 is sandwiched and pressed. The roller 2 is disposed in pressure contact with the heating body 5, and the heat-resistant film 6 is rotated and conveyed a as a film suspension roller 14 or the pressure roller 2 as a film drive roller. When the film suspension roller 14 is used as a driving roller, the pressure roller 2 is driven to rotate.

The heat-resistant film 6 shown in FIG.
Instead of an endless belt, a long end film wound in a roll is used, and the end film is wound from the feeding shaft 15 side to the winding shaft 16 side via the heating body 5,
The pressure roller 2 is brought into pressure contact with the heating body 5 with the film 6 sandwiched therebetween, and the film 6 is run and conveyed to the winding shaft 16 side. The pressure roller 2 may be a film driving roller.

In any of the devices shown in FIGS. 7 to 9, the heating element 5 is used.
The pressure roller 2 and the pressure roller 2 are an elastic heating element and a good heat conducting roller, respectively, similarly to those in the third embodiment, and have the same effects as those in the third embodiment.

<Fifth Embodiment> (FIG. 10) FIG. 10 shows an example of an image forming apparatus incorporating an image heating and fixing device A as a heating device of a heating roller type according to the present invention as shown in the first embodiment. Shows a schematic configuration of. The image forming apparatus of this embodiment is a reciprocating platen type, a rotary drum type, a transfer type, and a process cartridge attaching / detaching type electrophotographic copying apparatus.

Reference numeral 100 denotes an apparatus casing, 101 denotes a reciprocating type document placing table made of a transparent plate member such as a glass plate disposed on an upper surface plate 102 of the apparatus casing.
The upper part is driven to reciprocate to the right a and the left a'in the drawing at a predetermined speed.

Reference numeral G denotes an original, which is placed on the upper surface of the original placing table 101 according to a predetermined placing standard with the image surface side to be copied facing downward, and by placing the original pressure plate 103 on the original and pressing it. Set.

Reference numeral 104 denotes a slit opening serving as a document illuminating section which is opened on the surface of the upper surface plate 102 of the machine as a long side in a direction perpendicular to the reciprocating direction of the document placing table 101 (direction perpendicular to the paper surface).

The downward image surface of the document G placed and set on the document placing table 101 moves the positions of the slit openings 104 sequentially from the right side to the left side in the forward movement process of the document placing table 101 to the right a. The light L of the lamp 105 is passed through the slit opening 104 and the transparent original placing table 101 to be illuminated and scanned in the passing process, and the original surface reflected light of the illumination scanning light is reflected by the image element array 106 by the photosensitive drum. Image formation exposure is performed on the 107th surface.

The photosensitive drum 107 is coated with a photosensitive layer such as a zinc oxide photosensitive layer and an organic semiconductor photosensitive layer, and is rotated in a clockwise direction indicated by an arrow b at a predetermined peripheral speed around a central support shaft 108. During the rotation process, the charging device 109 receives a uniform positive or negative charging process, and the uniformly charged surface is subjected to the image formation exposure (slit exposure) of the original image, so that the surface of the photosensitive drum 107 is formed. An electrostatic latent image corresponding to the image-exposed original image is sequentially formed.

This electrostatic latent image is sequentially visualized by a developing device 110 with toner made of resin or the like that is softened and melted by heating, and the toner image as the visualized image is provided with a transfer discharger 111 as a transfer portion. It moves to the part.

Reference numeral S denotes a cassette in which transfer material sheets P as recording materials are stacked and housed, the sheets in the cassette are fed out and fed one by one by the rotation of the feeding roller 112, and then the drum is moved by the registration rollers 113. When the leading edge of the toner image forming portion on 107 reaches the portion of the transfer discharger 111, the leading edge of the transfer material sheet P also arrives at the position between the transfer discharger 111 and the photosensitive drum 107 so that they both coincide with each other. It is returned and is synchronously fed.

Then, the transfer discharger 111 sequentially transfers the toner image on the photosensitive drum 107 side to the surface of the fed sheet.

The sheet to which the toner image has been transferred at the transfer portion is sequentially separated from the surface of the photosensitive drum 107 by a separating means (not shown), and is guided to the fixing device A by the conveying device 114 to carry the unfixed toner. Receives heat fixing of the image,
An image formed product (copy) is discharged onto a paper discharge tray 117 outside the apparatus through a discharge roller 116.

The surface of the photosensitive drum 107 after the image transfer is subjected to the removal of adhering contaminants such as transfer residual toner by the cleaning device 118, and is repeatedly used for image formation.

The PC is a process cartridge which is attached / detached to / from the cartridge attaching / detaching portion 120 in the apparatus main body 100.
In the case of the present example, the apparatus main body 10 including the four process devices of the photosensitive drum 107 as an image bearing member, the charging device 109, the developing device 110, and the cleaning device 118 together.
It is detachable and replaceable with respect to 0.

[0101]

As described above, according to the present invention, in a heating device for heating a material to be heated at a pressure nip portion between a heating body and a pressure member, such as a heat roller method and a film heating method, non-sheet passing is performed. It is possible to alleviate or prevent the occurrence of temperature rise in the section, solve the various problems as described above due to the temperature rise in the non-sheet passing section, and solve the problem due to thermal expansion of the pressure member, The intended purpose is often achieved.

[Brief description of drawings]

FIG. 1 is a device according to a first embodiment (heating roller type heating device).
Cross-sectional model view of the main part of

FIG. 2 is a vertical cross-sectional model view of one end side of the heating roller

FIG. 3 is a schematic cross-sectional view of another configuration example of the pressure roller.

FIG. 4 is an apparatus of Example 2 (heating roller type heating apparatus)
Cross-sectional model view of the main part of

FIG. 5 is a schematic cross-sectional view of a main part of the apparatus of Example 3 (heating apparatus of film heating type).

FIG. 6 is an enlarged view of the pressure contact nip portion.

FIG. 7 is a diagram (No. 1) of another configuration example of the film heating type heating device.

FIG. 8 is a diagram of another example of the configuration of the film heating type heating device (Part 2).

FIG. 9 is a diagram (part 3) of another configuration example of the film heating type heating device.

FIG. 10 is a schematic configuration diagram of an image forming apparatus according to a fifth embodiment.

[Description of symbols] 1 heating roller 1a core material 1b heat insulating layer 1c elastic heating layer 1d heat-resistant release layer 1e energizing electrode 1f elastic layer 1g heating layer 2 pressing roller 2a as a pressing member good heat Conductive core material 2b Heat-resistant release layer 2c Heat-resistant thin rubber layer N Press-contact nip portion 5 Heater 5a Heater base material 5b Heat-generating layer 5c Heat-generating element protective layer 5d Heat-resistant elastic layer 5e Heater support 6 Heat-resistant film 7 Stay 8 Recording material as heating material

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toshio Miyamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Koichi Suwa 3-30-2 Shimomaruko, Ota-ku, Tokyo Kiya Non-Incorporated (72) Inventor Tatsuichi Tsukita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoru Izawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. In the company

Claims (8)

[Claims] 1. A heating device for heating a material to be heated at a pressure nip portion between a heating body and a pressing member, wherein the heating body is provided with elasticity and is elastically deformed between the heating body and the pressing member. A heating device characterized in that a pressure contact nip portion having a predetermined width is formed in the heating device. 2. A heat-resistant film in a pressure-contact nip portion formed by the heating body and the pressing member, wherein the heat-resistant film is brought into close contact with the heating member by a pressure member and slidably conveyed, and the heat-resistant film is sandwiched therebetween. A film heating type heating device that introduces a material to be heated between the pressure member and conveys the pressure nip portion together with the heat resistant film to apply the heat of the heating body to the material to be heated through the heat resistant film. The heating device is characterized in that the heating body is provided with elasticity, and a heat-resistant film is sandwiched between the heating body and the pressing member by elastic deformation of the heating body to form a pressure contact nip portion having a predetermined width. 3. The heating device according to claim 1, wherein the pressing member is a rigid body. 4. The heating device according to claim 1, wherein the pressing member is a good heat conductor. 5. The heating device according to claim 1, wherein the pressing member is a rotating body. 6. The heating device according to claim 1, wherein the heating body is a surface-heating type rotating body having elasticity. 7. The heating device according to claim 1, wherein the material to be heated is a recording material supporting a visible image and is a heating fixing device for heating the visible image. 8. An image forming apparatus comprising the heating device according to claim 1 as a heat fixing device for heating a visible image of a recording material.