JPH1078715A - Heating device and image forming device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the movement of a rotary body consisting of endless film in a length direction with simple constitution in a heating device having the rotary body and directly imparting heat energy to a material to be recorded from the heating layer of the rotary body or imparting the heat energy to the material to be recorded from a heating body through the rotary body. SOLUTION: This device is provided with the rotary body 10 consisting of the endless film and having the heating layer, a pressure member 30 forming a nip N between the rotary body 10 and the member 30, and an exciting coil applying magnetic field in the heating layer. Assuming that either diameter of the rotating body 10 is ϕ1 , the other diameter thereof is ϕ2 and an optional diameter except both ends is ϕx , relation ϕ1 <=ϕx <ϕ2 or ϕ1 <ϕx <=ϕ2 is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating body made of an endless film and a pressing member forming a nip between the rotating body and a recording member between the rotating body and the pressing member. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device that pinches and conveys a material to apply heat energy to a recording material directly from a heating layer of a rotating body, or to apply heat energy to a recording material from a heating body via a rotating body. In particular, the present invention relates to a heating device suitable for an image heating device used in an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus to fix an unfixed image on a recording material.

[0002]

2. Description of the Related Art An image heating apparatus used in an image forming apparatus,
For example, a heat roller system is conventionally known as a heat fixing device.

As the heat roller method, there are a fixing roller having a built-in halogen heater and a fixing roller generating an eddy current.

An image heating apparatus in which a halogen heater is built in a fixing roller is employed, for example, in a heat fixing apparatus of a color image recording apparatus having a maximum of four toner layers. That is, a halogen heater built in the fixing roller generates heat, and the toner image on the recording material is heated via the core metal of the fixing roller and the rubber elastic layer on the outer periphery of the core metal.

[0005] An image heating apparatus for generating an eddy current in the fixing roller is disclosed, for example, in Japanese Patent Publication No. 5-9027. In this image heating device, an eddy current is generated in a fixing roller by magnetic flux, and the fixing roller generates heat by Joule heat.

[0006]

However, according to the above-described image heating apparatus in which a halogen heater is incorporated in the fixing roller, since the heat capacity of the fixing roller is large, it takes time to sufficiently heat the fixing roller, and quick start-up is performed. There is a problem that can not be. Also, the use of a halogen heater is inefficient because energy is once converted into light.

In particular, in a color image forming apparatus, since a maximum of four toner layers are stacked, it is not possible to sufficiently heat the interface between the recording material and the toner layer only by incorporating the halogen heater in the fixing roller. May cause poor fixing. Therefore, the roller-type fixing device in the color image forming apparatus includes a halogen heater not only in the fixing roller but also in a pressure roller in contact with the fixing roller. However, it still takes a long time to sufficiently heat, and the problem that quick start cannot be performed remains. Further, since the heat capacity of both the fixing roller and the pressure roller becomes extremely large, there is a problem that power consumption is increased.

According to the image heating apparatus disclosed in Japanese Patent Publication No. 5-9027 for generating an eddy current in a fixing roller, when a fixing roller having a large heat capacity has heat, an exciting coil or an exciting core heats up. Therefore, there is a problem that the amount of magnetic flux is reduced and heat generation becomes unstable. In addition, since heat is radiated to the inside of the fixing roller, thermal efficiency is not sufficient.

In order to solve the problems (mainly due to the large heat capacity of the roller) of the method of heating by a halogen heater built in the roller and the method of generating an eddy current in the roller, A heating method using a film having a small heat capacity has been proposed.

A heating device using this film is shown in FIG.
As shown in FIG.
And a pressing member 30 that forms a nip between the rotating member 10 and the rotating member 10. The recording material (not shown) is nipped and conveyed between the rotating member 10 and the pressing member 30. The heat energy is directly applied to the recording material from the heat generating layer, or the heating energy is applied to the recording material from a heating body (not shown) via the rotating body 30.

By the way, this heating device needs to prevent the rotating body 10 from moving in the longitudinal direction. Since the heating device has the same diameter (the diameter of both ends and the central portion is the same) in the longitudinal direction of the rotating body 10, there is a possibility that the heating device moves in both longitudinal directions of the rotating body 10. for that reason,
A complicated mechanism is required to control the movement in both directions, or it is necessary to provide regulating members 21a and 21b at both ends of the rotating body 10 for regulating the deviation of the rotating body 10 in both directions.

An object of the present invention is to provide a rotating body made of an endless film, to apply heat energy to a recording material directly from a heating layer of the rotating body, or to record from a heating body via the rotating body. It is an object of the present invention to provide a heating device for applying heat energy to a material, wherein the heating device prevents movement of a rotating body in a longitudinal direction by a simple configuration.

[0013]

According to a first aspect of the present invention, an object of the present invention is to provide a rotating body made of an endless film having a heating layer and a pressurizing method for forming a nip between the rotating body and the rotating body. A heating element for generating a magnetic field in the heat generating layer and an exciting coil for generating an alternating magnetic field that generates an eddy current; In a heating device that applies thermal energy to a recording material from, when one diameter of the rotating body is φ ₁ , the other diameter is φ ₂ , and the diameter of any part except both ends of the rotating body is φ _x , φ _This is achieved by satisfying the relationship of ₁ ≦ φ _x <φ ₂ or φ ₁ <φ _x ≦ φ ₂ .

According to a second aspect of the present invention,
The object is to provide a rotating body made of an endless film, a heating body for heating the rotating body, and a pressing member for forming a nip between the rotating body and a pressing member between the rotating body and the pressing member. In a heating device that applies thermal energy to a recording medium from a heating body via a rotating body by pinching and conveying the recording material, one diameter of the rotating body is φ ₁ , the other diameter is φ ₂ , When the diameter of any portion except the both end portions and phi _x, is achieved by satisfying φ ₁ ≦ φ _x <φ ₂ or φ ₁ <φ _x ≦ φ ₂ relationship.

According to the third aspect of the present invention,
The above object is achieved in the first or second aspect of the invention by providing a restricting member for restricting the longitudinal movement of the rotating body near the smaller end of the rotating body. .

According to a fourth aspect of the present invention,
The object is to provide a rotating body made of an endless film having a heating layer, a pressing member that forms a nip between the rotating body and an exciting coil that generates an alternating magnetic field that creates an eddy current by applying a magnetic field to the heating layer. A heating device that applies heat energy to the recording material from the heat generating layer of the rotating body by nipping and transporting the recording material between the rotating body and the pressing member. Assuming that φ ₃ , the other diameter is φ ₄ , and the diameter of any part except both ends of the heating member is φ _y , the relationship of φ ₃ ≧ φ _y > φ ₄ or φ ₃ > φ _y ≧ φ ₄ is satisfied. This is achieved by:

According to a fifth aspect of the present invention,
The object is to provide a rotating body made of an endless film, a heating body for heating the rotating body, and a pressing member for forming a nip between the rotating body and a pressing member between the rotating body and the pressing member. In a heating device that applies thermal energy to a recording medium from a heating body via a rotating body by pinching and conveying the recording material, one diameter of the heating member is φ ₃ , the other diameter is φ ₄ , Assuming that the diameter of any part other than both ends is φ _y , this is achieved by satisfying the relationship of φ ₃ ≧ φ _y > φ ₄ or φ ₃ > φ _y ≧ φ ₄ .

According to the sixth aspect of the present invention,
The above object is achieved in the fourth or fifth aspect by providing a restricting member for restricting the longitudinal movement of the rotating body in the vicinity of the smaller diameter end of the pressing member. You.

According to a seventh aspect of the present invention,
The above object is achieved by the third or sixth aspect of the present invention, wherein the regulating member is provided so as to rotate at substantially the same speed as the end of the rotating body.

According to an eighth aspect of the present invention, the above object is attained in one of the first to seventh aspects, wherein the rotating body and the pressurizing member are arranged in a longitudinal dimension of the rotating body. Where L _F and the longitudinal dimension of the pressurizing member are L _{R. This} is achieved by satisfying the relationship of L _F > L _R.

According to a ninth aspect of the present invention, the above object is achieved by a heating apparatus according to one of the first to eighth aspects, wherein the heating device according to the first aspect of the present invention is adapted to remove an unfixed image formed on a recording material. This is achieved by configuring an image heating device that performs heat treatment to fix the image.

That is, in the first invention according to the present application, in the heating device in which the rotating body generates heat by electromagnetic force, the rotating body moves in the longitudinal direction only on the small diameter side.

According to the second aspect of the present invention, in a heating device for applying heat energy through a rotating body by a heating body, the rotating body moves in the longitudinal direction only on the small diameter side.

In the third invention according to the present application, the first invention
In the first or second invention, the rotating body rotates with one end of the rotating body abutting on the regulating member.

According to the fourth aspect of the present invention, in a heating device in which a nip is formed by a rotating body and a pressing member and the rotating body generates heat by electromagnetic force, heating elements having different diameters at both ends are provided. The pressure member rotates to move the rotating body only in one longitudinal direction.

According to a fifth aspect of the present invention, in a heating device in which a nip is formed between a rotating body and a pressing member and heat energy is applied by the heating body via the rotating body, The pressing members having different diameters rotate to move the rotating body only in one longitudinal direction.

In the sixth invention according to the present application, the fourth invention
In the fifth or fifth aspect of the present invention, the restricting member provided near the larger end of the pressing member restricts the movement of the rotating body in one longitudinal direction.

In the seventh invention according to the present application, the third invention
In one of the inventions to the sixth invention,
The restricting member rotates at substantially the same speed as the end of the rotator, and prevents the end of the rotator from sliding against the restricting member.

In the eighth invention according to the present application, the longitudinal dimension of the rotating body is longer than the longitudinal dimension of the pressing member, and the end on the small diameter side of the rotating body is inside the end of the pressing member. And the pressing member is prevented from being scraped by the end of the rotating body.

In the ninth invention according to the present application, the first invention
The heating device according to any one of the inventions to the eighth invention is an image forming apparatus constituting an image heating device, wherein a direction of a rotating body of the heating device is determined in one direction, and a regulating member is provided for the rotating body. One may be provided on the side of the approach direction.

[0031]

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

FIG. 10 shows an electrophotographic color printer as an example of an image forming apparatus using the image heating device (heat fixing device) 100 of the present invention.

The electrophotographic color printer of this embodiment comprises a photosensitive drum 101 made of an organic photosensitive member or an amorphous silicon photosensitive member, a charging roller 102 for uniformly charging the photosensitive drum 101, and an image signal generator. A laser optical box 110 for converting a signal (not shown) into an on / off state of a laser beam 103 to form an electrostatic latent image on the photosensitive drum 101, and selectively forming an electrostatic latent image on the photosensitive drum 101. Developing device 104 for adhering toner to form an image, intermediate transfer drum 105 to which a toner image is transferred by a potential difference between photosensitive drum 101, and electric charge of the opposite polarity to the toner are supplied from the back surface of recording material P Transfer roller 106 for transferring the toner image on the intermediate transfer drum 105 onto the recording material P
And an image heating device (heating and fixing device) 100 for applying heat and pressure to the recording material P on which the unfixed toner image is placed to perform permanent fixing on the recording material P.

Reference numeral 109 denotes a mirror. The cleaner 107 removes toner and paper dust remaining on the photosensitive drum 101. The cleaner 108 removes toner and paper dust remaining on the intermediate transfer drum 105.

The developing device 104 includes a yellow Y, magenta M, and cyan C color developing device and a black developing device Bk. The developing device 104 develops a latent image on the photosensitive drum 101 one color at a time and sequentially superimposes the toner images on the intermediate transfer drum 105 to obtain a color image.

Hereinafter, embodiments of the image heating apparatus of the present invention will be described.

(First Embodiment) FIGS. 1 and 6 show a first embodiment of the image heating apparatus of the present invention.

This image heating apparatus includes a fixing film 10 as a rotating body made of an endless film having a heating layer.
And a pressing roller 30 as a pressing member for forming a nip N between the fixing film 10 and an exciting coil 1 for generating an alternating magnetic field for generating an eddy current by applying a magnetic field to the heating layer.
8 is provided. Then, the rotating body 10 and the pressure roller 3
When the recording material P is nipped and conveyed between 0 and 0, thermal energy is applied to the recording material P from the heat generating layer of the fixing film 10.

In the present embodiment, as shown in FIG. 8, the fixing film 10 has a three-layer structure including a heat generating layer 1, an elastic layer 2, and a release layer 3 sequentially from the inner peripheral side to the outer peripheral side. (Layer structure will be described later in detail). In this embodiment, the fixing film 10 is rotated in the direction of the arrow in FIG. The fixing film 10 is pressurized to the nip N by the film guide 16 and transport stability is achieved. The film guide 16 is provided with a core 17 having a high magnetic permeability by a lower half peripheral portion 16a.
And the exciting coil 18. The upper half peripheral portion 16b guides the conveyance of the fixing film 10 exclusively.

The core 17 having a high magnetic permeability is preferably made of a material used for a transformer core, such as ferrite or permalloy, and more preferably a ferrite having a small loss even at 100 kHz or more.

The excitation coil 18 is connected to an excitation circuit 50 (see FIG. 7). This excitation circuit 50 has a frequency of 20 kHz.
A high frequency of 500 kHz from z is generated by a switching power supply. Heat fixing is performed by passing a recording material P on which unfixed toner T is placed through a nip N formed by the pressure roller 30 and the fixing film 10.

The heating principle is as follows. The magnetic flux generated by the current applied to the exciting coil 18 by the exciting circuit 50 is guided to the core 17 to generate an eddy current in the heat generating layer 1 of the fixing film 10. Heat is generated by the resistance.

The generated heat heats the recording material P conveyed to the nip N and the toner T on the recording material P via the elastic layer 2 and the release layer 3. The toner T is melted in the nip N and cooled after passing through the nip to form a permanently fixed image.

Next, the exciting coil 18 and the core 17 will be described.

The distance between the exciting coil 18 and the heat generating layer 1 of the fixing film 10 is preferably as short as possible. The reason is that the magnetic field generated by the exciting coil 18 and the core 17 is efficiently absorbed by the heat generating layer 1 of the fixing film 10.

Therefore, the exciting coil 18 and the fixing film 1
As shown in FIG. 6, the excitation coil 18 was arranged along the curved surface of the fixing film 10 so that the region having a distance between 0 and 0 was as large as possible. In the present embodiment, the distance between the heating layer 1 and the exciting coil 18 is set to 1 mm.

When the distance between the exciting coil 18 and the heat generating layer 1 of the fixing film 10 exceeds 5 mm, the magnetic flux absorption efficiency decreases, so that it is preferable to keep the distance within 5 mm. Within 5 mm, the heating layer 1 of the fixing film 10 and the exciting coil 1
It is not necessary that the distance to 8 be constant.

In the present embodiment, the windings of the exciting coil 18 are arranged in one row. However, the present invention is not limited to this, and two or more rows may be wound.

Next, the fixing film 10 will be described.

FIG. 1 shows a combination of a fixing film 10 and a pressure roller 30.

Assuming that _one diameter of the rotating body is φ ₁ , the other diameter is φ ₂ , and the diameter of any part except both ends of the rotating body is φ _x , φ ₁ ≦ φ _x <φ It is formed so as to satisfy ₂ or φ ₁ <φ _x ≦ φ ₂ relationship.

For example, it is formed in a shape as shown in FIGS. Thereby, the longitudinal movement (deviation) of the fixing film 10 is set to one direction A.

Therefore, as shown in FIG. 1, one end of the fixing film 10 is always in contact with the regulating member 21a at the end of the fixing film 10, so that the fixing film 10 is prevented from moving in the longitudinal direction, and stable rotation is achieved. Becomes In addition, since the regulating member 21a only needs to be provided on one side in the shift direction A, the regulating member 21a is provided on both sides of the fixing film 10 (FIG. 5).
) Can be reduced in cost and space can be saved.

Next, the layer structure of the fixing film 10 will be described in detail.

FIG. 8 shows an example of the fixing film 10.

The fixing film 10 shown in FIG. 8 includes a heat generating layer 1, an elastic layer 2, and a release layer 3 sequentially from the inside to the outside.
Consists of layers.

The heat generating layer 1 is a base layer of the fixing film 10 and is made of a metal or the like. When a magnetic flux enters, an eddy current is generated to generate Joule heat.

The metal used as the material of the heat generating layer 1 may be a non-magnetic metal. However, more preferably, metals such as nickel, iron, magnetic stainless steel, and cobalt-nickel alloy that absorb magnetic flux are good.

The heat generating layer 1 may be formed by stacking a resin layer in which a metal filler or the like is mixed on a heat resistant and strong resin film such as polyimide without using a metal as a base material. Good.

The thickness of the heat generating layer 1 is preferably larger than the skin thickness expressed by the following equation and 200 μm or less.

The skin thickness σ [m] is determined by the frequency f of the excitation circuit.
[Hz], the magnetic permeability μ, and the specific resistance ρ [Ωm] can be expressed as σ = 503 × (ρ / fμ) ^1/2 .

The skin thickness σ indicates the depth of absorption of electromagnetic waves used in electromagnetic induction, and the electromagnetic wave intensity E is 1 / e or less at a deep portion. Most of the energy is absorbed up to this skin thickness (see FIG. 11).

The thickness of the heat generating layer 1 is preferably 1 to 100
μm is good. When the thickness is smaller than 1 μm, most of the electromagnetic energy cannot be absorbed, so that the efficiency is deteriorated. On the other hand, if it exceeds 100 μm, the rigidity becomes too strong and the flexibility becomes poor, and it is not practical to use as the rotating body 10.

The elastic layer 2 is provided to make the fixing film 10 elastic. As the material of the elastic layer 2, a material having good heat resistance and good thermal conductivity is selected. Examples of such a material include silicone rubber, fluorine rubber, and fluorosilicone rubber.

The elastic layer 2 preferably has a thickness of 10 to 1000 μm. This thickness is necessary to guarantee the quality of the fixed image, as described below.

When a color image is printed, a solid image is formed over a large area on the recording material P, especially for a photographic image. In this case, if the release layer 3 serving as the heating surface cannot follow the unevenness of the recording material P or the unevenness of the toner layer, uneven heating occurs, and uneven gloss occurs in an image in a portion having a large amount of heat transfer and a portion having a small amount of heat transfer. . That is, a portion having a large amount of heat transfer has high gloss, and a portion having a small amount of heat transfer has low gloss. When the thickness of the elastic layer 2 is less than 10 μm, the elastic layer 2 cannot follow irregularities of the recording material P or the toner layer, and uneven image gloss occurs. On the other hand, when the thickness is 1000 μm or more, the thermal resistance of the elastic layer 3 becomes large, and it is difficult to realize a quick start. Therefore, the elastic layer 2
Is preferably 10 to 1000 μm, more preferably 50 to 500 μm.

If the hardness of the elastic layer 2 is too high, the elastic layer 2 cannot follow the irregularities of the recording material P or the toner layer, resulting in uneven image gloss. Therefore, the hardness of the elastic layer 2 is preferably 60 ° (JIS-A) or less, more preferably 45 ° (JIS-A) or less.

The thermal conductivity λ of the elastic layer 2 is 6 × 10 ⁻⁴ to
2 × 10 ⁻³ [cal / cm · sec · deg. ] Is good. Thermal conductivity λ is 6 × 10 ⁻⁴ [cal / cm · sec ·
deg. ], The thermal resistance is large, and the temperature rise in the surface layer of the fixing film 10 becomes slow. On the other hand, the thermal conductivity λ is 2 × 10 ⁻³ [cal / cm · sec ·
deg. ], The hardness becomes too high and the compression set becomes worse.

Therefore, the thermal conductivity λ is, as described above,
6 × 10 ^{-4 to} 2 × 10 ^-3 [cal / cm · sec · de
g. ] Is good. More preferably, 8 × 10 ^{−4 to} 1.5 ×
10 ⁻³ [cal / cm · sec · deg. ] Is good.

The release layer 3 is a heating surface in contact with the recording material P.

The material of the release layer 3 is selected from those having good releasability and good heat resistance. Such materials include:
Fluororesin, silicone resin, fluororesin silicone rubber, fluororubber, silicone rubber, PFA, PTFE,
FEP and the like.

The release layer 3 preferably has a thickness of 1 to 100 μm. If the thickness is less than 1 μm, there arises a problem that a part having poor releasability is formed due to unevenness of the coating film and durability is insufficient. On the other hand, when the thickness exceeds 100 μm, a problem that heat conduction is deteriorated occurs. In particular, in the case of a resin-based release layer, the hardness becomes too high, and the effect of the elastic layer 2 is lost.

Further, as shown in FIG. 9, the fixing film 10 may be provided with a heat insulating layer 4 on the innermost side of the layer structure shown in FIG. 8 to improve the thermal efficiency.

In the case where the heat insulating layer 4 is provided, heat is generated so that the heat generated in the heat generating layer 1 does not go to the inside of the fixing film 10. Heat supply efficiency is improved. Thereby, power consumption can be suppressed.

The heat insulating layer 4 is preferably made of a heat resistant resin.
As this heat-resistant resin, fluororesin polyimide resin, polyamide resin, polyamideimide resin, PEEK resin, P
ES resin, PPS resin, PFA resin, PTFE resin, F
EP resin and the like.

The heat insulating layer 4 has a thickness of 10 μm to 10 μm.
00 μm is preferred. When it is smaller than 10 μm, the heat insulating effect cannot be obtained and the durability is insufficient. On the other hand, 1000
If it exceeds μm, the distance from the core 17 to the heat generating layer 1 increases, and the magnetic flux cannot be sufficiently absorbed by the heat generating layer 1.

Next, the pressure roller 30 will be described.

The pressure roller 30 is formed by covering a core metal with silicone rubber, fluorine rubber or the like. The pressure roller 30 is rotated by a drive mechanism (not shown).

In order to supply thermal energy from the pressure roller 30 to the recording material P, a heating element may be provided on the pressure roller 30.

Next, the fixing film 10 and the pressure roller 30
Will be described in the longitudinal direction.

The longitudinal dimension of the fixing film 10 and the pressure roller 30 is determined by setting the longitudinal dimension of the fixing film 10 to L _F ,
When the longitudinal dimension of the pressing roller 30 and L _R, is set so as to satisfy the relationship L _F> L _R.

[0082] longitudinal dimension L _F of the fixing film 10 is a longer portion than the pressure roller L _R, the regulating member 21a side is La, the opposite side of the regulating member 21a and Lb. Then, La is moved from the end of the pressure roller 30 to the regulating member 21a.
The distance may be set to be longer than the initial distance to. Also, Lb
May be set to be equal to or larger than the maximum dimensional tolerance between the pressure roller 30 and the fixing film 10. Therefore, the minimum value of Lb can be set to zero.

Thus, the large diameter φ ₂ of the fixing film 10
Side is no longer inside the end of the pressure roller 30, and the end of the fixing film 10
0 can be prevented from being scraped off.
A stable rotation of 0 can be obtained.

In this embodiment, a toner T containing a low softening substance is used. Therefore, although an oil application mechanism for preventing offset is not provided, an oil application mechanism may be provided when a toner containing no softening substance is used.

Further, a cooling section may be provided downstream of the fixing nip to perform cooling separation.

In the present embodiment, a four-color image formation is described. However, the present invention may be applied to a monochrome or one-pass multi-color image forming apparatus. As described above, when the monochrome and one-pass multicolor image forming apparatus is used, the elastic layer 2 may be omitted from the fixing film 10.

According to the image heating apparatus configured as described above, the fixing film 10 shifts in one direction as follows.

The pressure roller 30 is rotated by a drive mechanism (not shown). Following the pressure roller 30, the fixing film 10 rotates. Then, the alternating magnetic field generated by the exciting coil 18 enters the heating layer 1 of the fixing film 10 and causes the heating layer 1 to generate heat. In this state, the recording material P is nipped and conveyed between the fixing film 10 and the pressure roller 30 to apply heat energy from the heat generating layer 1 of the fixing film 10 to the recording material P to perform a fixing action. .

The fixing film 10 has a smaller diameter φ ₁ ,
That is, only the arrow A moves in one direction. Accordingly, one end of the fixing film 10 is always in contact with the regulating member 21a, so that the fixing film 10 is prevented from moving in the longitudinal direction, and stable rotation is achieved. Thus, the regulating member 21a
Need only be provided in one approach direction A side.

(Second Embodiment) In the second embodiment, in addition to the image heating device of the first embodiment, a regulating member 2 is provided.
1a is configured to rotate at substantially the same speed as the fixing film 10. (This will be described with reference to FIG. 1 as a drawing.) This prevents rubbing between the end portion of the fixing film 10 and the regulating member 21a, and prevents damage due to abrasion deterioration of the end portion of the fixing film 10 due to rubbing. In addition, the life of the fixing film 10 is extended.

[0091] As a method of rotating the regulating member 21a, for example, there is the following method.

Using the biasing force of the fixing film 10,
The fixing film 10 is driven to rotate by the frictional force between the end surface of the fixing film 10 and the regulating member 21a.

A gear (not shown) is provided on the regulating member 21a, and a rotational driving force is applied from the outside so that the speed is substantially equal to that of the fixing film 10.

However, the fixing film 10 and the regulating member 2
What is necessary is just to rotate 1a at substantially constant speed, and the rotation method is not limited to this.

According to the second embodiment configured as described above, the regulating member 21a rotates at substantially the same speed as the fixing film 10 to prevent the end portion of the fixing film 10 from sliding against the regulating member 21a. Further, damage due to abrasion deterioration of the end portion of the fixing film 10 due to rubbing is prevented.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS.

The image heating apparatus of the third embodiment is similar to that of FIG.
As shown in (1), the fixing film 10 is formed to have the same diameter in the longitudinal direction of the film, while the diameter of the pressure roller 30 is changed at both ends, as compared with the first embodiment.

Assuming that one diameter of the heating roller 30 is φ ₃ , the other diameter is φ ₄ , and the diameter of any part of the heating roller 30 except for both ends thereof is φ _y , the pressing roller 30 has φ ₃ ≧ φ is set to satisfy a relationship of _y> phi ₄ or _{φ 3> φ y ≧ φ 4} .

For example, it is formed in a shape as shown in FIGS. Thus, a peripheral speed difference is provided at both ends of the pressure roller 30, and the direction in which the fixing film 10 rotates following the pressure roller 30 is defined as one direction A. Therefore, the fixing film 10 is always in contact with the regulating member 21a, preventing the fixing film 10 from moving in the longitudinal direction, and obtaining stable rotation of the fixing film 10. The regulating member 21a may be provided only on one side of the fixing film 10 in the direction A (the larger diameter of the pressure roller 30), and the cost is reduced as compared with the case where the regulating member 21a is provided on both sides of the fixing film 10.

In the third embodiment, the regulating member 21a may be rotated at substantially the same speed as the fixing film 10 as in the second embodiment.

Further, when the pressure roller 30 having different diameters at both ends in the third embodiment and the fixing roller 10 having different diameters at both ends shown in the first embodiment are combined,
An effect similar to that of the third embodiment is obtained.

According to the image heating apparatus of the third embodiment described above, the peripheral speed difference is provided at both ends of the pressure roller 30 so that the direction in which the fixing film 10 rotates following the pressure roller 30 is shifted in one direction A. It is set to (If larger diameter phi ₃ of the pressing roller 30).

Therefore, the fixing film 10 always comes into contact with the regulating member 21a.
0 is prevented from moving in the longitudinal direction, and stable rotation of the fixing film 10 is obtained. Fixing member 21a to fixing film 10
Side A side (larger diameter of pressure roller 30)
Only need to be provided.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG.

In the fourth embodiment, heat energy is applied to the recording material P from the heater 202 as a heating element via the fixing film 10. This is different from the first to third embodiments in that the fixing film 10 itself generates heat.

The heater 202 includes a heater substrate 203, an electric resistance material 204 on the lower surface of the heater substrate 203, and a heat-resistant protective layer 205. The heater stay 201 is provided to support the heater 202 and guide the rotation of the fixing film 10.

The type of the heating element is not limited as long as it can apply heat energy through the fixing film 10.

The fixing film 10 has a conductive layer (heat generation layer 1) for generating heat in the first to third embodiments, but the conductive layer is omitted in the fourth embodiment. be able to.

In the image heating apparatus according to the fourth embodiment, similarly to the above-described embodiments, the fixing film 10 or the heating roller 30 is configured such that the diameter of the heating roller 30 is different at both ends, so that the fixing film 10 can be one. It is only necessary to displace in one direction and to arrange only one of the regulating members.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made.

For example, in the above-described embodiment, the fixing film 10 rotates following the rotation of the pressure roller 30, but the invention is not limited to this, and the fixing film 10 may be driven to rotate. . The heating device illustrated in FIG. 12 applies tension to the fixing film 10 by the tension roller 20 and drives the fixing roller 10 by the driving roller 19.

[0112]

As described above, the first embodiment according to the present application is described.
According to the invention, in a heating device of a type in which the rotating body itself generates heat by electromagnetic force, one diameter of the rotating body is φ ₁ ,
Assuming that the other diameter is φ ₂ and the diameter of any part other than both ends of the rotating body is φ _x , the relationship of φ ₁ ≦ φ _x <φ ₂ or φ ₁ <φ _x ≦ φ ₂ is satisfied.

Therefore, the direction in which the rotating body approaches is determined in one direction, and only one regulating member needs to be provided on the approaching side of the rotating body, so that the regulating member is provided on both ends of the rotating body. Thus, costs can be reduced. Further, since the rotating body is shifted only in one direction, stable rotation can be obtained.

According to the second aspect of the present invention,
In a heating device of a type in which heat energy is applied by a heating body through a rotating body, one diameter of the rotating body is φ ₁ , the other diameter is φ ₂ , and a diameter of an arbitrary portion excluding both ends of the rotating body is Is φ _x , the relationship of φ ₁ ≦ φ _x <φ ₂ or φ ₁ <φ _x ≦ φ ₂ is satisfied.

Therefore, the direction in which the rotating body approaches is determined in one direction, and only one regulating member needs to be provided on the approaching side of the rotating body, so that the regulating member is provided on both end sides of the rotating body. Thus, costs can be reduced. Further, since the rotating body is shifted only in one direction, stable rotation can be obtained.

According to the third aspect of the present invention,
In the first invention or the second invention, since the regulating member for regulating the longitudinal movement of the rotating body is provided near the end of the rotating body having the smaller diameter, the regulating member is provided at both ends of the rotating body. The cost can be reduced as compared with the case where it is provided on the unit side.

Further, according to the fourth invention of the present application,
In a heating device that forms a nip between a rotating body and a pressing member and heats the rotating body itself by electromagnetic force, one diameter of the heating member is φ ₃ , the other diameter is φ ₄ , and both ends of the heating member Assuming that the diameter of any part other than is φ _y , the relationship of φ ₃ ≧ φ _y > φ ₄ or φ ₃ > φ _y ≧ φ ₄ is satisfied. Therefore, the direction in which the rotating body is shifted is determined in one direction, and one regulating member may be provided on the side in which the rotating body is shifted, so that the cost is reduced as compared with the case where the regulating member is provided on both ends of the rotating body. Can be achieved. Further, since the rotating body is shifted only in one direction, stable rotation can be obtained.

Further, according to the fifth invention of the present application,
In a heating device that forms a nip between a rotating body and a pressing member and applies thermal energy through the rotating body by the heating body, one diameter of the heating member is φ ₃ , the other diameter is φ ₄ , When the diameter of any portion except for the both end portions of the member and phi _y, satisfies the relationship of φ ₃ ≧ φ _y> φ ₄ or _{φ 3> φ y ≧ φ 4} .

Therefore, the direction in which the rotating body approaches is determined in one direction, and only one regulating member needs to be provided on the approaching side of the rotating body, so that the regulating member is provided on both end sides of the rotating body. Thus, costs can be reduced. Further, since the rotating body is shifted only in one direction, stable rotation can be obtained.

According to the sixth invention of the present application,
In the fourth invention or the fifth invention, since the regulating member that regulates the longitudinal movement of the rotating body is provided near the end of the pressure member having the smaller diameter, the regulating member is attached to the rotating body. The cost can be reduced as compared with the case where both ends are provided.

Further, according to the seventh invention of the present application,
In one of the third invention to the sixth invention, the regulating member is provided so as to rotate at substantially the same speed as the end of the rotating body, so that the end of the rotating body and the regulating member are connected to each other. The rubbing is prevented, the end of the rotating body due to the rubbing is prevented from being damaged due to wear deterioration, and the life of the rotating body can be extended.

Further, according to the eighth invention of the present application,
When the longitudinal dimension of the rotator L _F, the longitudinal dimension of the pressure member and L _R, to satisfy the relationship L _F> L _R.

As a result, the end of the rotating body on the small diameter side does not become inside the end of the pressing member, so that it is possible to prevent the pressing member from being cut off by the end of the rotating body and to stabilize the rotating body. Rotation is obtained.

According to the ninth invention of the present application,
An image forming apparatus includes the heat generating device according to one of the first to eighth inventions. Therefore, the direction in which the rotating body of the heating device approaches is determined in one direction, and only one regulating member may be provided on the approaching side of the rotating body, so that the regulating member is provided on both end sides of the rotating body. Thus, costs can be reduced. Further, since the rotating body is shifted only in one direction, stable rotation can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment of a heating device of the present invention.

FIGS. 2A, 2B, and 2C are perspective views each showing an example of a rotating body that can be used in the heating device of FIG. 1;

FIG. 3 is a front view of a heating device according to a third embodiment of the present invention.

FIGS. 4A, 4B, and 4C are perspective views of examples of a pressing member that can be used in the heating device of FIG. 3;

FIG. 5 is a front view of a conventional heating device.

FIG. 6 is a longitudinal sectional view of the heating device according to the first embodiment of FIG. 1;

FIG. 7 is a perspective view of a magnetic flux generator used in the heating device according to the first embodiment of FIG. 1;

FIG. 8 is an enlarged cross-sectional view illustrating a layer configuration of an example of a rotating body used in the heating device of the present invention.

FIG. 9 is an enlarged cross-sectional view illustrating a layer configuration of another example of the rotating body used in the heating device of the present invention.

FIG. 10 is a schematic sectional view of an image forming apparatus using the heating device of the present invention.

FIG. 11 is a graph showing a relationship between a heating layer depth and an electromagnetic wave intensity.

FIG. 12 is a sectional view showing a modification of the heating device of the present invention.

FIG. 13 is a sectional view of a heating device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 fixing film (rotating member) 18 excitation coil 21a regulating member 30 pressing roller (pressing member) 202 heater (heating member) N nip

Continued on the front page (72) Inventor Hiroki Kisu 3-2-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (9)

[Claims] 1. A rotating body made of an endless film having a heating layer, a pressing member forming a nip between the rotating body and an excitation for generating an alternating magnetic field for generating an eddy current by applying a magnetic field to the heating layer. A heating device having a coil and applying heat energy to the recording material from a heating layer of the rotating body by nipping and transporting the recording material between the rotating body and the pressing member; Is φ ₁ , the other diameter is φ ₂ , and the diameter of any part except both ends of the rotating body is φ _x , satisfying the relationship of φ ₁ ≦ φ _x <φ ₂ or φ ₁ <φ _x ≦ φ ₂ A heating device. 2. A rotator made of an endless film,
A heating element that heats the rotating body, and a pressing member that forms a nip between the rotating body and a pressing member that sandwiches and conveys the recording material between the rotating body and the pressing member. In a heating device that applies thermal energy to a recording material via a rotating body, one diameter of the rotating body is φ ₁ , the other diameter is φ ₂ , and the diameter of any part except both ends of the rotating body is φ _x to _{the, φ 1 ≦ φ x <φ} 2 or φ ₁ <φ _x ≦ φ heating apparatus characterized by satisfying the _two relationships. 3. The heating device according to claim 1, wherein a regulating member for regulating longitudinal movement of the rotating body is provided near an end of the rotating body having a smaller diameter. . 4. A rotating body made of an endless film having a heating layer, a pressing member forming a nip between the rotating body, and an excitation for generating an alternating magnetic field for generating an eddy current by applying a magnetic field to the heating layer. A heating device having a coil and applying thermal energy to the recording material from the heat generating layer of the rotating body by nipping and transporting the recording material between the rotating body and the pressing member; Is φ ₃ , the other diameter is φ ₄ , and the diameter of any part except both ends of the heating member is φ _y , satisfying the relationship of φ ₃ ≧ φ _y > φ ₄ or φ ₃ > φ _y ≧ φ ₄ A heating device. 5. A rotating body made of an endless film,
A heating element that heats the rotating body, and a pressing member that forms a nip between the rotating body and a pressing member that sandwiches and conveys the recording material between the rotating body and the pressing member. In a heating device that applies thermal energy to a recording material via a rotating body, one diameter of a heating member is φ ₃ , the other diameter is φ ₄ , and the diameter of an arbitrary portion excluding both ends of the heating member is φ _y to _{the, φ 3 ≧ φ y> φ} 4 or φ _3> φ _y ≧ φ heating apparatus characterized by satisfying the ₄ relationship. 6. In the vicinity of the larger end of the pressure member,
The heating device according to claim 4 or 5, further comprising a regulating member that regulates movement of the rotating body in the longitudinal direction. 7. The heating device according to claim 3, wherein the regulating member is provided so as to rotate at substantially the same speed as an end of the rotating body. The 8. rotator and the pressure member, the longitudinal dimension of the rotator L _F, the longitudinal dimension of the pressure member when the L _R, claim to be satisfied the relationship L _F> L _R The heating device according to any one of claims 1 to 7. 9. The image heating apparatus according to claim 1, wherein the heating apparatus heats and fixes an unfixed image formed on the recording material. Image forming apparatus.