JPH1174068A - Heating device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device and an image forming apparatus in which an adhered substance is prevented from adhering to a rotating body, and problems such as contamination by the adhered substance and deterioration of separability of a material to be heated are prevented. To do. SOLUTION: A conductive rotating body 1 and a pressing member 5 forming a nip portion N with the rotating body 1, and a material to be heated is provided at a nip portion N between the rotating body 1 and the pressing member. In the heating device 100 that heats the material to be heated by nipping and conveying
A conductive plate 10 is provided on an end portion of the rotating body 1 in the rotation axis direction, and the rotating body 1 and the conductive plate 10 are conducted, and a sliding member 11 is provided in contact with the conductive plate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for pressurizing a material to be heated.
The present invention relates to a heating device for heating, and an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording device provided with the heating device as an image heating unit or a fixing unit.

[0002]

2. Description of the Related Art Conventionally, as an image heating apparatus typified by a heat fixing apparatus which is provided in an image forming apparatus such as a copying machine or a printer and heats and fixes an unfixed toner image on a recording material, a heat roller system is used. Things are widely used.

A fixing device as a heating device of the heat roller type basically has a pressure roller pair of a fixing roller (heating roller) and a pressure roller, and the roller pair is rotated to rotate the roller pair. The recording material on which the unfixed image is formed is introduced into the fixing (heating) nip portion, which is a mutual press contact portion, and is nipped and conveyed. The unfixed image is covered by the heat of the fixing roller and the pressing force of the fixing nip portion. This is to fix the recording material with heat and pressure.

The fixing roller generally has a hollow metal roller made of aluminum or the like as a base (core metal), and a halogen lamp as a heat source is inserted in the hollow space thereof. Of the halogen lamp is controlled so that the temperature is maintained at a predetermined fixing temperature.

On the other hand, Japanese Unexamined Utility Model Publication No. 51-109736 discloses an induction heating fixing device in which a current is induced in a fixing roller by magnetic flux and heat is generated by Joule heat of the current. This makes it possible to directly generate heat from the fixing roller by utilizing the generation of an induced current, and achieves a fixing process with higher efficiency than a heat roller type fixing device using a halogen lamp as a heat source.

Further, as shown in US Pat. No. 5,278,618, a fixing roller as a heating element is used as a film to improve the efficiency by lowering the entire heat capacity, or to obtain a higher density of energy acting on the fixing. An electromagnetic induction heating-type fixing device has also been devised in which the excitation coil is moved closer to the fixing roller to improve efficiency.

[0007]

However, the above-described fixing device (heating device) has the following problems.

In general, when the image surface of the material to be heated is sequentially separated from the fixing roller after passing through the nip portion between the fixing roller and the pressure roller, a part of the toner constituting the image becomes larger or smaller. It remains on the fixing roller. This phenomenon is referred to as offset. Particularly, when a plurality of images with a large amount of loaded toner are to be heated in succession, the amount of adhered toner increases. There has been a problem that the separability of the heating material is deteriorated and the image surface is stained by re-adhering to the material to be heated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and prevents the attached matter from adhering to the rotating body, thereby causing inconveniences such as contamination by the attached matter and deterioration of separability of a material to be heated. It is an object of the present invention to provide a heating device and an image forming apparatus that prevent the occurrence of the heating.

[0010]

According to the present invention, there is provided a heating apparatus and an image forming apparatus having the following constitutions.

[1]: A conductive rotating body, and a pressing member forming a nip portion with the rotating body, and a material to be heated is nipped and conveyed at a nip portion between the rotating body and the pressing member. In the heating device that heats the material to be heated, a conductive plate is provided on an end of the rotating body in the rotation axis direction, and the rotating body and the conductive plate are brought into conduction, and the sliding body is brought into contact with the conductive plate to slide. A heating device comprising a member.

[2]: A conductive rotating body and a pressing member forming a nip with the rotating body, and the material to be heated is nipped and conveyed by the nip between the rotating body and the pressing member. In the heating device that heats the material to be heated, an insulating holding ring and a conductive plate are provided on the rotating shaft end side of the rotating body, and the rotating body and the conductive plate are electrically connected to each other. A sliding member provided in contact with the heating device.

[3]: It has a conductive rotating body and a pressing member forming a nip portion with the rotating body, and the material to be heated is nipped and conveyed by the nip portion between the rotating body and the pressing member. In the heating device for heating the material to be heated by doing so, a conductive holding ring is provided on the rotation axis direction end side of the rotating body, and a sliding member is provided in contact with the holding ring. Heating equipment.

[4]: A bias is applied to the rotating body via the sliding member.
The heating device according to [2] or [3].

[5]: An electromagnetic induction heat generating member which is a rotating body, a first member having a magnetic field generating means for generating a magnetic field by applying a magnetic field to the electromagnetic induction heat generation member, and directly or otherwise on the first member. A second member that is a pressing member that forms a nip portion by mutually pressing the members therebetween, and imparts thermal energy of the electromagnetic induction heating member to the material to be heated that is introduced into the nip portion and is nipped and conveyed; The heating device according to any one of [1] to [4], wherein the material to be heated is heated.

[6]: The material to be heated is a recording material on which an image to be subjected to a heat treatment is carried, and as an image heating means for heating the image, any one of [1] to [5]. A heating device comprising the heating device according to claim 1.

[7]: an image forming means for forming and carrying a developer image on a recording material, and an image heating means for heating the developer image formed and carried on the recording material; An image forming apparatus, wherein the image heating means is the heating device according to any one of [1] to [5].

[8]: An image forming means for forming and carrying an unfixed image on a recording material, and a fixing means for fixing the unfixed image formed and carried on the recording material, wherein the fixing means are [ 1]
An image forming apparatus, which is the heating apparatus according to any one of claims 1 to 6.

[0019]

[9]: an image carrier as a member to be charged, charging means for charging the image carrier, exposure means for exposing the image carrier to form an electrostatic latent image, and Developing means for adhering toner to form a toner image, transfer means for transferring the toner image on the image carrier to a transfer material, and fixing means for making the toner image transferred to the transfer material a permanent fixed image And an image forming apparatus, wherein the fixing unit is the heating device according to any one of [1] to [6].

(Effect) The above-mentioned structure allows the adhered material such as toner to be charged to the same polarity as the adhered material, or by removing the charge from the rotator so as not to be charged to a polarity different from that of the adhered material. It is prevented from being attached to the rotating body by electric power or the like, thereby preventing contamination by the attached matter and deterioration of separability of the material to be heated.

In particular, in a case where an image forming apparatus or a heating device as an image heating unit or a fixing unit is used to continuously heat a plurality of images having a large amount of loaded toner, the toner is fixed by electrostatic force or the like. By preventing the toner from adhering to a rotating body such as a film, it becomes possible to prevent the deterioration of the separability of the material to be heated by the toner and the occurrence of defects such as an image defect due to the reattachment to the material to be heated. .

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] §1. Overall Configuration of Heating Device The present embodiment is a heating fixing device as a heating device according to the present invention. The heat fixing device of this example is an electromagnetic induction heating type / pressure roller drive type device using a cylindrical film as an electromagnetic induction heating member.

FIG. 1 is a schematic front view of a main part of the fixing device 100 of this embodiment, FIG. 2 is a schematic cross-sectional view of the main part, and FIG. FIG. 4 is an enlarged view of a cross section of the film, and FIG. 5 is a schematic cross-sectional view near the end of the film.

The heating and fixing device 100 of this embodiment is a rotating member as an electromagnetic induction heating member, that is, a cylindrical electromagnetic induction heating film (fixing film) as an endless belt.
1, a film guide member 2, an excitation coil 3 and a magnetic core (core metal) 4 as magnetic field generating means, and a pressure roller 5 as a pressure member. A recording material P as a material to be heated, in which an unfixed toner image t is formed and carried in the fixing nip portion N in contact, is introduced,
The recording material P is heated by electromagnetic induction heating of the fixing film 1 while applying pressure to the recording material P in the fixing nip portion N, so that the unfixed toner image t is fused and fixed to the surface of the recording material P.

As shown in FIG. 4, the fixing film 1 includes a heat generating layer 1a made of a metal film or the like serving as a base layer of the electromagnetic induction heat generating film, an elastic layer 1b laminated on the outer surface thereof,
It has a three-layer composite structure of a release layer 1c laminated on its outer surface.

The heat generating layer 1a is made of nickel, iron, ferromagnetic SU.
It is preferable to use a ferromagnetic metal such as S, a nickel-cobalt alloy, or the like, and a thickness of 1 to 100 μm is preferable from the relationship between electromagnetic energy absorption efficiency and film rigidity.

When fixing a color image or the like, the elastic layer 1b causes the heating surface (release layer 1c) to follow the unevenness of the recording material P or the unevenness of the toner layer of the unfixed toner image t so that the gloss of the image is improved. It is a layer necessary to prevent unevenness, and a layer having high heat resistance and good thermal conductivity such as silicone rubber, fluorine rubber, or fluorosilicone rubber is used, and has a thickness of 10 to 50.
The thickness is preferably 0 μm and the hardness is 60 ° or less (JIS-A).

The release layer 1c is made of a fluororesin, silicone resin, fluorosilicone rubber, fluororubber, silicone rubber, PFA, PTFE, FEP having a thickness of 1 to 100 μm.
Those having good releasability and heat resistance such as are used.

The free side of the heat generating layer 1a (the heat generating layer 1a
(A side opposite to the elastic layer 1b side), a heat insulating layer is provided to insulate the heat generated in the heat generating layer 1a so as not to go to the inside of the fixing film, thereby improving the heat supply efficiency to the recording material P side. It is good also as a structure to make it.

The film guide member 2 is formed of a phenol resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PTFE resin, a FEP resin, an LCP resin, and the like in order to secure insulation between the excitation coil 3 and the fixing film 1. A material having good heat resistance is used, and pressure is applied to a pressure contact portion (fixing nip portion N) against the pressure roller 5, support of the exciting coil 3 and the magnetic core 4 as magnetic field generating means, support of the fixing film 1, and fixing. It serves to improve the transport stability of the film 1 during rotation.

The exciting coil 3 is formed by winding a bundle of a plurality of thin copper wires, each of which is individually insulated and coated, around the magnetic core 4 a plurality of times, thereby forming a coil (wire loop). A pair of lead wires (feed lines) are connected to an excitation circuit (not shown). In this embodiment, the excitation coil 3 is made of polyimide having a heat resistance of 6 turns (6 turns) using polyimide as a heat-resistant insulating film. The diameter of the thin wire, the cross-sectional area of the bundled wire, and the like are determined by the amount of current flowing through the exciting coil 3.
This bundle (bundled wire cross-sectional area of about 3.1 mm ² ) is used. The exciting coil 3 wound around the magnetic core 4 as described above
The fixing film 1 is provided continuously over a width in a direction orthogonal to the moving direction of the fixing film 1 (axial direction of the fixing film 1).

The excitation core 4 is a core having a T-shaped cross section, and is made of a material used for a transformer core such as ferrite or permalloy (more preferably, ferrite which has no loss even at 100 kHz or more).

The pressure roller 5 is composed of a core metal 5a and a heat-resistant and elastic material 5b such as silicone rubber, fluoro rubber or fluoro resin formed and coated around the core metal.
Both ends of the cored bar 5a are rotatably supported by bearings between a sheet metal (not shown) of the apparatus.

As shown in FIGS. 1 and 3, a fixing film 1, a film guide member 2, an exciting coil 3, an exciting core 4, a pressing rigid stay 6, and a flange member are provided above the pressing roller 5. A heating unit (first member) composed of holding rings 7a and 7b is provided, and both ends of the rigid pressurizing stay 6 and spring receiving members 8a and 8 on the device chassis side.
The compression springs 9a and 9b are contracted between them, respectively, to apply a downward force to the stay 6 for pressure rigidity.
As a result, the lower surface of the film guide member 2 and the upper surface of the pressure roller 5 (first member) are pressed against each other with the fixing film 1 interposed therebetween to form a fixing nip portion N having a predetermined width.

The pressure roller 5 is driven to rotate in a counterclockwise direction shown by an arrow in FIG. This pressure roller 5
A rotational force acts on the fixing film 1 by a frictional force between the pressure roller 5 and the outer surface of the fixing film 1 by the rotational driving of the fixing film 1, and the fixing film 1 moves its inner surface to the lower surface of the film guide member 2 at the fixing nip N. The film guide member 2 is rotated around the film guide member 2 at a peripheral speed substantially corresponding to the rotational speed of the pressure roller 5 in the clockwise direction shown by the arrow while sliding in close contact. The heating principle in the fixing nip N is as follows.

An alternating current of 20 kHz to 500 kHz flows from an exciting circuit (not shown) to the exciting coil 3 to generate an alternating magnetic flux. The alternating magnetic flux generates an eddy current in the heat generating layer 1a of the fixing film 1, and the eddy current generates Joule heat due to the specific resistance of the heat generating layer 1a. The generated heat heats the recording material P nipped and conveyed to the nip N via the elastic layer 1b and the release layer 1c and the unfixed toner image t on the recording material P.

§2. Flange Member and Conductive Plate In this embodiment, the end of the film 1 is regulated by holding rings 7a and 7b, which are flange members, so that the running stability of the film 1 is improved.
1 to apply a bias to the film 1.

The holding ring 7 is made of a phenol resin, a polyimide resin, a polyamide resin, a polyamide-imide resin,
EEK resin, PES resin, PPS resin, PFA resin, P
The ring-shaped cap is made of a material having good insulation and heat resistance such as TFE resin, FEP resin, and LCP resin, and has a thickness of 0.5 to 3 mm. The retaining ring 7 is rotatably attached to the end of the guide member 2 in a state where the movement in the axial direction is restricted, and the rotation stability of the film 1 is secured by restricting the shift of the film 1. doing. Since the retaining ring 7 is configured to rotate with the film 1, there is no possibility of causing damage such as abrasion or cracking of the film end when regulating the deviation.

The conductive plate 10 is a ring-shaped member made of a conductive material such as metal and having a thickness of 0.1 to 3 mm, and is rotatably provided outside the holding ring 7b at the end of the film guide member. I have. Further, as shown schematically in FIG. 5, the conductive plate 10 is electrically connected to the heat generating layer 1a of the film 1 through a contact 10a (such as an elastic member or a conductive adhesive). And is configured to rotate with the film 1 via the contact or the holding ring 7b.

A chip-shaped sliding member 11 made of a conductive and heat-resistant material such as metal or carbon is provided on the device substrate 100a so as to be in contact with the conductive plate 10. A bias (fixing bias) is applied from the power supply 12 via the power supply 12.

As the fixing bias, for example, a DC bias having the same polarity as that of the toner is applied. The bias value to be applied may be appropriately set according to the configuration, environment, and the like of the apparatus, and a bias in which an AC bias is superimposed on a DC bias may be applied. A configuration may also be adopted in which a bias applying unit is provided on the pressure roller, and a bias is applied to both the film and the pressure roller.

The conductive plate 10 and the holding ring 7b, and the holding rings 7a and 7b and the film 1 may or may not be bonded and fixed depending on the rotation stability of the film 1.

§3. Effects of this embodiment With the above configuration, the film 1 can be charged to the same polarity as the toner, and the toner can be prevented from adhering to the film 1 due to electrostatic force or the like. For this reason, there is no occurrence of contamination by the attached toner and deterioration of the separability of the heated material P.

In particular, even when a plurality of images having a large amount of loaded toner are heated in succession, the toner can be prevented from adhering to the fixing film 1 by electrostatic force or the like, and the separation of the material to be heated by the toner is deteriorated. In addition, it is possible to prevent the occurrence of a defect such as an image defect due to re-adhesion to the material to be heated.

Also, since the sliding member 11 for applying the bias is rubbed against the conductive plate 10 without directly rubbing against the film, the sliding member 11 is not affected by deterioration of the film and the like even during durability. The bias could be applied stably, and the image could be formed satisfactorily.

Table 1 shows the results of evaluating the offset by continuously passing a plurality of images with a large amount of loaded toner using the heating device of this embodiment. As a comparative example, the results for the case without the sliding member and the bias applying means are also shown.

[0047]

[Table 1] As described above, in the comparative example, defects such as image stains and poor separation occur due to the offset, whereas in the present example, a good image free from defects due to the offset was obtained.

§4. Modification of this embodiment FIG. 6 shows a modification of this embodiment. FIG. 6A is a schematic cross-sectional view of one end of the apparatus, and FIG. 6B is a schematic perspective view of the flange member 13. In this modification, a conductive flange member 13 made of metal or the like is used instead of the above-described conductive plate 10.

The flange member 13 is formed by, for example, pressing a copper plate, and is fitted to the film 1 from outside the holding ring 7b. The flange member 13
Indicates a plurality of protrusions (fixed contacts) provided on the film 1 side
13 a is fixed by being pressed against the heat generating layer on the inner surface of the film by elastic force like a leaf spring, and rotates with the rotation of the film 1.

The flange member 13 also has a sliding member 11
The fixing bias is applied by the power supply 12 via the sliding member 11.

By adopting the above configuration, similar to the effect of the first embodiment, problems such as deterioration of the separability of the material to be heated due to the adhered toner and image defects due to re-adhesion to the material to be heated are caused. This can be prevented.

In this embodiment, the film 1 is connected to the projection 13a of the flange member 13 in a substantially fixed state, and the sliding member 11 serving as a sliding contact is rubbed against the flange member 13. Was not directly rubbed, and good image formation was able to be performed without being affected by deterioration of a film or the like even during durability.

Also in this example, when a plurality of images having a large amount of loaded toner were continuously passed and the evaluation of the offset was performed, a good image free from any problem due to the offset was obtained.

[Second Embodiment] In this embodiment, as shown in FIG. 7, the insulating holding ring 7b of the first embodiment is replaced with a conductive holding ring 14, and the holding ring 14 is slid. In this configuration, a member 11 is provided and a fixing bias is applied.

The holding ring 14 is made of phenol resin, polyimide resin, polyamide resin, polyamide imide resin,
PEEK resin, PES resin, PPS resin, PFA resin,
It is made conductive by dispersing a conductive filler such as carbon or metal in a heat-resistant resin such as PTFE resin, FEP resin or LCP resin.

The holding ring 14 is adhered and fixed to the inner surface of the film so as to be electrically connected to the heat generating layer on the inner surface of the film, and is rotated by being guided by the film guide 2 as the film 1 rotates.

In this embodiment, the holding ring 14 and the film 1 are bonded and fixed. However, when the rotation stability of the film 1 is ensured, the holding ring 1 is not necessarily used.
The film 4 and the film 1 do not need to be bonded and fixed.

With the above-described configuration, the toner is prevented from adhering to the fixing film 1 due to the offset even when a plurality of images with a large amount of loaded toner are to be heated successively. It is possible to prevent deterioration of the separability of the material to be heated due to the adhesion of the toner, and occurrence of problems such as image defects due to the re-adhesion of the offset toner to the material to be heated.

Further, by making the holding ring conductive, the conductive plate 10 in the first embodiment can be omitted, so that the configuration can be simplified.

Also in this example, when a plurality of images with a large amount of loaded toner were actually passed continuously and the evaluation of the offset was performed, a good image free from any trouble caused by the offset was obtained.

[Third Embodiment] This embodiment is an example of a film heating type fixing device using a ceramic heater as a heating element.

FIG. 8 is a front model diagram of the apparatus 200, FIG. 9 is a vertical cross-sectional model diagram, and FIG. 10 is a horizontal cross-sectional model diagram.

Reference numeral 18 denotes a heat-resistant and heat-insulating film guide having a substantially semicircular cross-section, and reference numeral 17 denotes a ceramic heater as a heating element, which is formed substantially at the center of the lower surface of the film guide 18 along the guide length. It is fitted into the groove and fixedly supported.

Reference numeral 16 denotes a cylindrical or endless heat-resistant fixing film. The fixing film 16 is loosely fitted on a film guide 18.

Reference numeral 25 denotes a phenol resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PEEK resin, a PES resin fitted to one end of the film guide 18.
Resin, PPS resin, PFA resin, PTFE resin, FEP
An annular flange member made of a resin, a heat-resistant resin such as an LCP resin, and made conductive by dispersing a conductive filler such as carbon and metal. Thus, the bias applying member also functions.

Reference numeral 20 denotes a rigid stay for pressure inserted inside the film guide 18.

The above-mentioned film guide 18, ceramic heater 17, fixing film 16, annular flange member 25,
The assembly of the pressing rigid stays 20 is referred to as a “heating assembly” for convenience.

Reference numeral 19 denotes an elastic pressure roller as a pressure member, which is provided with an elastic layer 19b of silicone rubber or the like on a core metal 19a to reduce the hardness. Both ends of the core metal 19a are not shown in the drawing. The bearings are rotatably held between the chassis side plates. Further, in order to improve the surface properties, a fluororesin layer such as PTFE, PFA and FEP may be further provided on the outer periphery.

On the upper side of the pressure roller 19, the above-mentioned heating assembly is disposed with the lower surface side of the film guide 18 facing downward, and the both ends of the stay 20 and the spring receiving members 21 and 21 of the apparatus chassis side plate side. Pressing spring 2 between each
The stays 20 are depressed by applying the pressing force to the stays 20 by contracting them. As a result, the film guide 18 is pressed and the lower surface of the ceramic heater 17 disposed on the lower surface of the film guide 18 and the pressing roller 19 are fixed to the fixing film 16.
The fixing nip portion N is formed by pressing the fixing nip therebetween.

The pressure roller 19 is driven by the driving means M in FIG.
It is driven to rotate counterclockwise as indicated by the arrow in the middle. A rotational force acts on the fixing film 16 by the frictional force between the pressing roller 19 and the outer surface of the fixing film 16 due to the rotation of the pressing roller 19, and the inner surface of the fixing film 16 is fixed at the fixing portion nip N by the ceramic. The outer periphery of the film guide 18 is rotated in a clockwise direction as indicated by an arrow at a peripheral speed substantially corresponding to the rotation speed of the pressure roller 19 while sliding in close contact with the lower surface of the heater 17 (pressure roller driving method).

In order to reduce the mutual sliding friction force between the lower surface of the ceramic heater 17 and the inner surface of the fixing film 16 in the fixing nip N, the lower surface of the ceramic heater 17 in the fixing nip N and the inner surface of the fixing film 16 are reduced. Lubricant such as heat resistant grease is interposed.

The rotation of the pressure roller 19 is started based on the print start signal.
Is started. When the rotation peripheral speed of the fixing film 16 due to the rotation of the pressure roller 19 is stabilized and the temperature of the ceramic heater 17 rises to a predetermined value, the fixing film 16 in the fixing nip N and the pressure roller 1
9, a recording material P carrying a toner image t as a material to be heated is introduced with the toner image carrier surface facing the fixing film 16 so that the recording material P becomes a fixing nip N
In the ceramic heater 1 via the fixing film 16
7, the fixing nip N is fixed to the lower surface of the fixing film 16.
And move along with it. In the moving passage process, the heat of the ceramic heater 17 is applied to the recording material P via the fixing film 16 and the toner image t is heated and fixed on the surface of the recording material P. Recording material P that has passed through fixing nip portion N
Is transported separately from the surface of the fixing film 16.

The fixing film 16 has a film thickness of 100 μm or less, preferably 50 μm or less, preferably 20 μm or more, or a single layer of a metal film, or PTFE, A composite layer film coated with PFA, FEP or the like can be used. In this example, Ni (nickel)
An electroformed film having a diameter of 20 mm with an outer peripheral surface coated with PTFE was used.

The ceramic heater 17 as a heating element is
The fixing film 16 is a horizontally long linear heating element having a low heat capacity and having a longitudinal direction perpendicular to the moving direction of the recording material P. FIG. 11 is a schematic cross-sectional view of the ceramic heater 17.
A heater substrate 17a made of alumina or the like, and a heat generating layer 17b provided along the surface of the heater substrate 17a, for example, an electric resistance material such as Ag / Pd (silver / palladium) are used.
The heat generating layer 17b has a basic configuration of a heat generating layer 17b applied by screen printing or the like to a thickness of 1 μm and a width of 1 to 5 mm, and a protective layer 17c of glass, fluororesin, or the like provided thereon.

When current is applied between both ends of the heat generating layer 17b of the ceramic heater 17, the heat generating layer 17b generates heat and the temperature of the heater 17 rises rapidly. The heater temperature is detected by a temperature sensor (not shown), and the power supply to the heat generating layer 17b is controlled by a control circuit (not shown) so that the heater temperature is maintained at a predetermined temperature, and the temperature of the heater 17 is controlled.

The ceramic heater 17 is fitted and fixed to a groove formed in a substantially central portion of the lower surface of the film guide 18 along the guide length with the protective layer 17c side exposed. Therefore, in the fixing nip portion N, the surface of the protective layer 17c of the ceramic heater 17 and the inner surface of the fixing film 1 slide in contact with each other.

The flange member 25 at the longitudinal end of the film
Is provided with a sliding member 11 such as a carbon chip, and the sliding member 11 is connected to a power supply 12 to apply a bias to the film.

The applied bias is appropriately set depending on the conditions of the apparatus and the like. In this example, the applied bias is set so as to apply 0 V (earth).

With the above-described configuration, even when an image having a large amount of loaded toner is to be heated continuously for a plurality of sheets, it is possible to prevent the toner from adhering to the fixing film due to the offset, and to prevent the toner from adhering. It is possible to prevent the separation of the material to be heated from deteriorating, and to prevent problems such as image defects due to re-adhesion to the material to be heated.

In this embodiment, the ceramic heater 1
Reference numeral 7 denotes an example in which the heat generating layer 17b is disposed on the fixing film 16 side. However, the present invention is not limited to this, and the surface opposite to the heating surface (film sliding surface) of a substrate having good heat conductivity using aluminum nitride or the like is used. A backside heating type ceramic heater provided with a heating layer may be used.

[Fourth Embodiment] The present embodiment is, for example, an image forming apparatus using the heat fixing device of the first embodiment. FIG. 12 is a schematic configuration diagram of the image forming apparatus. The image forming apparatus of this example is an electrophotographic color printer.

Reference numeral 101 denotes an electrophotographic photosensitive drum (image carrier) made of an organic photosensitive member or an amorphous silicon photosensitive member, which is rotated at a predetermined process speed (peripheral speed) in a counterclockwise direction indicated by an arrow.

The photosensitive drum 101 undergoes a uniform charging process of a predetermined polarity and potential by a charging device 102 such as a charging roller during its rotation.

Then, a laser beam 103 output from a laser optical box (laser scanner) 110 is provided on the charged surface.
And scanning exposure processing of the target image information. The laser optical box 110 outputs laser light 103 modulated (on / off) in response to a time-series electric digital pixel signal of target image information from an image signal generator such as an image reader (not shown), and The drum surface is subjected to scanning exposure, and the scanning exposure forms an electrostatic latent image corresponding to the target image information scanned and exposed on the rotating photosensitive drum 101 surface. 10
Reference numeral 9 denotes a mirror for deflecting the output laser light from the laser optical box 110 to the exposure position of the photosensitive drum 101.

In the case of forming a full-color image, scanning exposure and latent image formation are performed on a first color-separated component image of a target full-color image, for example, a yellow component image. Is developed as a yellow toner image by the operation of the yellow developing device 104Y. The yellow toner image is transferred onto the surface of the intermediate transfer drum 105 at a primary transfer portion T1 which is a contact portion (or a close portion) between the photosensitive drum 101 and the intermediate transfer drum 105. After the transfer of the toner image to the surface of the intermediate transfer drum 105, the surface of the rotating photosensitive drum 101 is
7 removes adhered residues such as transfer residual toner and is cleaned.

The above-described process cycle of charging, scanning exposure, development, primary transfer, and cleaning is performed by the second color separation component image of the target full-color image (for example, the magenta component image, the magenta developing device 104M operates). , The third color component image (for example, cyan component image, cyan developing device 104C)
Is activated), and the color separation component images of the fourth color component image (for example, the black component image, the black developing unit 104BK is activated) are sequentially executed, and a yellow toner image, a magenta toner image, and cyan are formed on the surface of the intermediate transfer drum 105. Toner image
The four color toner images, which are the black toner images, are sequentially transferred in a superimposed manner, and a color toner image corresponding to the target full-color image is synthesized and formed.

The intermediate transfer drum 105 has a medium-resistance elastic layer and a high-resistance surface layer on a metal drum, and has the same peripheral speed as the photosensitive drum 101 in contact with or close to the photosensitive drum 101. Is rotated clockwise as indicated by an arrow, and a bias potential is applied to the metal drum of the intermediate transfer drum 105 so that a toner image on the photosensitive drum 101 side is applied to the surface of the intermediate transfer drum 105 by a potential difference from the photosensitive drum 101. Transfer to

The color toner image synthesized and formed on the surface of the intermediate transfer member 105 is
In a secondary transfer portion T2, which is a contact nip portion between the recording material P and a transfer roller (transfer device) 106, the surface of the recording material P sent from the paper supply portion (not shown) to the secondary transfer portion T2 at a predetermined timing It is transcribed. The transfer roller 106 supplies a charge having a polarity opposite to that of the toner from the rear surface of the recording material P, thereby sequentially transferring the combined color toner images collectively from the surface of the intermediate transfer drum 105 to the recording material P.

The recording material P that has passed through the secondary transfer portion T2 is separated from the surface of the intermediate transfer drum 105, introduced into the image heating device (fixing device) 100, and subjected to the heat fixing process of the unfixed toner image. The sheet is discharged to a discharge tray (not shown) outside the apparatus as a color image formed product. The image heating device 100 is, for example, the heat fixing device of the first embodiment.

After the transfer of the color toner image onto the recording material P, the rotating intermediate transfer drum 105 is cleaned by the cleaner 108 by removing the residual toner such as untransferred toner and paper dust. The cleaner 108 is normally kept in a non-contact state with the intermediate transfer drum 105, and is kept in contact with the intermediate transfer drum 105 in the process of performing the secondary transfer of the color toner image from the intermediate transfer drum 105 to the recording material P. Is held.

The transfer roller 106 is always kept in a non-contact state with the intermediate transfer drum 105, and during the secondary transfer of the color toner image from the intermediate transfer drum 105 to the recording material P, the intermediate transfer member Drum 10
5 is held in contact with the recording material P via the recording material P.

In the image forming apparatus of this embodiment,
Electrophotographic photosensitive drum (image carrier) 1 as a member to be charged
01, a charging roller (charging device) 102 for charging the electrophotographic photosensitive drum 101, and the electrophotographic photosensitive drum 1
Exposure apparatus 110 for exposing 01 to form an electrostatic latent image;
A developing device 104 for forming a toner image by attaching toner to the electrostatic latent image; transfer devices 105 and 106 for transferring the toner image on the electrophotographic photosensitive drum 101 onto a recording material P as a transfer material; Thereby, an image forming means for forming and carrying an unfixed toner image (unfixed image) on the recording material is configured.

The image forming apparatus of this embodiment can also execute a print mode of a mono-color image such as a black and white screen. Also, a double-sided image print mode or a multiple image print mode can be executed.

In the case of the double-sided image print mode, the recording material P on which the first-side image has been printed out of the image heating device 100 has been printed.
Is turned upside down via a recirculation transport mechanism (not shown), is again sent to the secondary transfer portion T2, receives the toner image transfer on the two surfaces, and is again introduced into the image heating device 100 to transfer the toner image on the two surfaces. By receiving the fixing process, a double-sided image print is output.

In the case of the multi-image print mode, the recording material P on which the first image has been printed out of the image heating device 100 has been printed.
Is transferred to the secondary transfer portion T2 again without being turned upside down via a recirculation transport mechanism (not shown), receives the second transfer of the toner image on the surface on which the first image has been printed, and returns to the image heating device 100 again. The multi-image print is output by being subjected to the second toner image fixing process after being introduced.

As described above, when a full-color image is formed, the amount of loaded toner tends to increase due to the combination with a plurality of toner images and the increase of solid-coated portions. In addition, it is possible to prevent deterioration of the separability of the material to be heated due to the offset toner and occurrence of problems such as image defects due to reattachment to the material to be heated.

[Others] The heating device of the present invention is the fixing device 1 described in the above embodiment.
Not only 00 and 200, but also an image heating device such as a device for heating a transfer material carrying an image to improve the surface properties (such as gloss), a device for assuming a toner image, and a sheet-like material. It can be widely used as a heating device such as a device for feeding and drying / laminating.

[0098] In the above-described embodiment, the bias is applied to the film 1. However, the present invention is not limited to this, and the film 1 may be grounded via a sliding member, or may be slid (friction) between the rotating body and the sliding member. A configuration may be employed in which the rotating body is charged or neutralized so that the rotating body is not charged with a different polarity from the attached matter such as toner.

[0099]

As described above, according to the present invention, a heating device which prevents deposits from adhering to a rotating body and prevents problems such as dirt caused by the deposits and deterioration of separability of a material to be heated. An apparatus and an image forming apparatus can be provided.

Particularly, in a case where a plurality of images having a large amount of loaded toner are continuously heated in an image forming apparatus or a heating apparatus as an image heating means, toner adheres (offsets) to a rotating body such as a fixing film. This makes it possible to prevent deterioration of the separability of the material to be heated due to the adhesion of the toner and problems such as image defects due to reattachment to the material to be heated.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a heat fixing device according to a first embodiment;

FIG. 2 is a schematic cross-sectional view of a main part of the apparatus.

FIG. 3 is a longitudinal cross-sectional front view of a main part of the apparatus.

FIG. 4 is a model diagram of a layer structure of a fixing film of the apparatus.

FIG. 5 is a simplified view of a longitudinal end of the device.

FIG. 6 is a simplified view of a longitudinal end portion of a modification of the first embodiment.

FIG. 7 is a simplified view of a longitudinal end portion of the heat fixing device according to the second embodiment.

FIG. 8 is a schematic front view of a heat fixing device according to a third embodiment;

FIG. 9 is a front view of a longitudinal section of a main part of the apparatus.

FIG. 10 is a cross-sectional model view of a main part of the apparatus.

FIG. 11 is a schematic cross-sectional view of a ceramic heater of the apparatus.

FIG. 12 is a schematic configuration diagram of an image forming apparatus provided with the heat fixing device, and is a schematic configuration diagram of a heating device showing another example of a film driving system;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 16 Fixing film 2, 18 Film guide member 5, 19 Pressure roller 6, 20 Rigid stay for pressure 7a, 7b, 13, 25 Flange member 10 Conductive plate 11 Sliding member 12 Power supply 14 Holding ring 100, 200 Heat fixing apparatus

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsuyoshi Abe 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (9)

[Claims] 1. A heating member having a conductive rotator and a pressing member forming a nip with the rotator, wherein the nip portion between the rotator and the pressing member conveys a material to be heated. In the heating apparatus for heating the material to be heated, a conductive plate is provided on an end portion of the rotating body in the rotation axis direction, the conductive body is electrically connected to the rotating body, and the sliding member is brought into contact with the conductive plate to form a sliding member. A heating device, comprising: 2. A heating member having a conductive rotator and a pressing member forming a nip with the rotator, wherein the nip portion between the rotator and the pressing member sandwiches and conveys a material to be heated. In the heating device for heating the material to be heated in the above, an insulating holding ring and a conductive plate are provided on an end side in the rotation axis direction of the rotating body, and the rotating body and the conductive plate are electrically connected to each other. A heating device comprising a sliding member provided in contact therewith. 3. A heating member having a conductive rotator and a pressing member forming a nip with the rotator, wherein the nip portion between the rotator and the pressing member sandwiches and conveys a material to be heated. A heating device for heating a material to be heated, wherein a conductive holding ring is provided at an end of the rotating body in the rotation axis direction, and a sliding member is provided in contact with the holding ring. apparatus. 4. A bias is applied to said rotating body via said sliding member.
A heating device as described. 5. An electromagnetic induction heating member as a rotating body, a first member having a magnetic field generating means for applying a magnetic field to the electromagnetic induction heating member to generate heat, and directly or other members being attached to the first member. A second member that is a pressing member that forms a nip portion by being sandwiched and pressed against each other, and by applying heat energy of the electromagnetic induction heating member to the material to be heated that is introduced into the nip portion and pinched and conveyed. 5. The heating method according to claim 1, wherein the material to be heated is heated.
The heating device according to Item. 6. The heating device according to claim 1, wherein the material to be heated is a recording material carrying an image to be subjected to a heat treatment, and the image heating means for heating the image. A heating device comprising: 7. An image forming means for forming and carrying a developer image on a recording material, and an image heating means for heating the developer image formed and carried on the recording material, An image forming apparatus, wherein the means is the heating device according to claim 1. 8. An image forming means for forming and carrying an unfixed image on a recording material, and a fixing means for fixing an unfixed image formed and carried on the recording material, wherein the fixing means is provided. An image forming apparatus, which is the heating apparatus according to any one of claims 1 to 6. 9. An image carrier as a member to be charged, charging means for charging the image carrier, exposure means for exposing the image carrier to form an electrostatic latent image, and the electrostatic latent image Developing means for forming a toner image by adhering toner to the toner, transferring means for transferring the toner image on the image carrier to a transfer material, and fixing means for making the toner image transferred to the transfer material a permanent fixed image An image forming apparatus, comprising: a heating device according to claim 1, wherein the fixing unit is a heating device according to claim 1.