JPH07295412A - Image fixing device of electrophotographic type image formation device - Google Patents

Abstract

PURPOSE:To obtain an image fixing device of electrophotographic image forming device which can prevent degradation of image quality due to the toner stuck to a heat resistance film, in a simple constitution. CONSTITUTION:An image of toner 19 formed on a recording medium 18, is fixed to the recording medium 18 by laminating, heating and pressurizing a heating body 11, and a heat resistance film 14. A heat resistance film 14 is supplied from a supply side reel 15, carried at a speed the same as that of the recording medium 18 between a heating body 11 and a pressurizing roller 13 held by means of a heating body support member 12, then collected by means of collecting side reel 17 via a film carrying roller 16. The excessive toner stuck to the heat resistance film 14 is collected by means of a toner collecting tray 20. Since fixing is performed always by means of a new heat resistance film 14, image quality can be improved. Measures for preventing the toner from being stuck to the heat resistance film 14 are alleviated, any circulation mechanism is no more required, and cost reduction can be achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image fixing device for an electrophotographic image forming apparatus, and more particularly, it is used in an electrophotographic image forming apparatus such as a printer, a facsimile and a copying machine and has a toner image formed thereon. The present invention relates to an image fixing device of an electrophotographic image forming apparatus that heats and fixes a toner image on the surface of a medium.

[0002]

2. Description of the Related Art Conventionally, in an image fixing device of an electrophotographic image forming apparatus, a heat fixing method is generally used for fixing a toner image on the surface of a recording medium. This method
A fixed pressure is applied between a pair of rollers, one of which is heated, and a recording medium on which an unfixed toner image is formed is passed between the rollers to fix the image. Recently, a heating element (ceramic heater, etc.) that can rapidly generate heat up to the fixing temperature in order to shorten the preheating time of the heating element.
There is an image fixing device having a configuration as shown in FIG.

In this image fixing device, a heating element 1 for softening the toner for enhancing the fixing property is supported by a heating element support member 2. The pressure roller 3 and the heating element 1 face each other and are pressed, while the heat resistant film 4 is conveyed by the drive pulley 5 and the heat resistant film 4 is circulated.

In the above structure, the recording medium 6 on which an unfixed toner image is formed is conveyed in the direction of arrow A and passes between the pressure roller 3 and the heat resistant film 4. At this time, the toner 7 heated by the heating element 1 via the heat resistant film 4 is softened, and is pressed by the pressure roller 3 to be fixed on the recording medium 6.

As a prior art example related to the present invention, Japanese Patent Laid-Open No.
No. 372972 discloses a toner image on a heat-resistant belt, which forms electrostatic latent images of plural colors as a toner image on a photosensitive belt and electrostatically transfers the toner image to a rotating heat-resistant belt. Is melted by heating, and the fused toner image is transferred onto a medium such as paper and fixed at the same time.

Further, in JP-A-2-39057, a heat-resistant film is stretched endlessly around a heating roll and a peeling roll, and a toner image formed on a support is pressed against the heat-resistant film in an overlapping manner. After heating and bringing the support and the heat-resistant film into close contact with each other and running for a predetermined time, the support and the heat-resistant film are peeled off.

[0007]

However, in the image fixing device in which the heat-resistant film is interposed between the toner and the heating element as described above, the toner on the surface of the recording medium adheres to the heat-resistant film, and Toner that adheres to and remains on the recording medium may scatter during circulation of the heat-resistant film and re-attach to the recording medium. To avoid this, special coating is applied to make it difficult for toner to adhere to the heat-resistant film, and silicone oil is supplied to the surface of the heat-resistant film.
Alternatively, it is necessary to take measures such as using a toner remover.
These measures are accompanied by problems that cause the price of the device to rise.

It is an object of the present invention to provide an image fixing device of an electrophotographic image forming apparatus which has a simple structure and can prevent deterioration of image quality due to toner attached to a heat resistant film.

[0009]

In order to achieve the above object, an image fixing device of an electrophotographic image forming apparatus of the present invention heats a toner image formed on a recording medium with a heating element and a heat-resistant film overlaid. And an image fixing device of an electrophotographic image forming apparatus for fixing a toner image to a recording medium by applying pressure, wherein a heat-resistant film supplying means for supplying a heat-resistant film and a heat-resistant film supplied from the heat-resistant film supplying means are heated and It is characterized in that it has a heat-resistant film collecting means for collecting it after pressurizing, and heats and pressurizes the heat-resistant film in one direction from the heat-resistant film supplying means to the heat-resistant film collecting means.

Further, the image fixing device of the electrophotographic image forming apparatus further has a toner collecting means, and the toner falling from the heat resistant film after heating and pressurizing may be collected by the toner collecting means.

[0011]

Therefore, according to the image fixing device of the electrophotographic image forming apparatus of the present invention, the heat-resistant film is supplied, and the heat-resistant film supplied is heated and pressed, and then collected.
The heat resistant film is conveyed in one direction and heated and pressed. With such a structure, since a new portion of the heat resistant film is used for image fixing, it is not necessary to take a measure for preventing toner adhesion to the heat resistant film. Further, since the heat-resistant film does not have a structure of circulation / reuse, it becomes easy to take a measure for collecting the excess toner adhering to the heat-resistant film, and the collection efficiency can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image fixing device of an electrophotographic image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, there is shown an embodiment of an image fixing device of an electrophotographic image forming apparatus of the present invention.

In the image fixing device of the embodiment, a heating element 11 for improving the fixing property of toner, a heating element support member 12 for holding the heating element 11, a pressure roller 13 arranged to face the heating element 11, The heat-resistant film 14 interposed between the pressure roller 13 and the heating element 11, the supply-side reel 15 for conveying the heat-resistant film 14, the film-conveying rollers 16, 16, the collecting-side reel 17 for collecting the heat-resistant film 14, the toner 1.
Recording medium 18 for fixing the image of No. 9 and surplus toner 1
9 and a toner recovery tray 20 for recovering 9.

In the above structure, the heat generating element 11 and the pressure roller 13 are pressed against each other, and the unfixed toner 19 on the recording medium is heated by the heat resistant film 14 by this pressing force. Pressed.

The heat-resistant film 14 is interposed between the pressure roller 13 and the heating element 11, and is conveyed by the film conveying roller 16 from the supply-side reel 15 and then the collecting-side reel 1.
Recovered to 7.

In the fixing operation of the image fixing device, the recording medium 18 on which an unfixed toner image is formed is conveyed in the direction of arrow A and passes between the pressure roller 13 and the heat resistant film 14. At this time, the heat-resistant film 14 is transferred from the supply reel 15 to the recording medium 18 by the film conveying roller 16.
It is transported at the same speed as that of. In this conveyance, when the recording medium 18 passes between the heating element 11 and the pressure roller 13, the unfixed toner 19 is heated by the heating element 11 via the heat resistant film 14.

By this heating, the toner 1 on the recording medium 18
9 softens and the fixability increases. The unfixed toner 19 having the improved fixing property is pressed against the recording medium 18 by the pressure roller 13 and fixed on the recording medium 18.

The heat-resistant film 14, which is sequentially supplied from the supply reel 15 and conveyed, intervenes in fixing the unfixed toner 19 to the recording medium 18 and prevents fusion of the toner to the heating element 11. The heat-resistant film 14 allows the toner 19 to be applied to the heating element 11.
Therefore, a clear toner image is fixed on the recording medium.

The heat-resistant film 14 that has passed between the heating element 11 and the pressure roller 13 at the same speed as the recording medium 18 is conveyed and guided by the conveying rollers 16 and 16, and the collecting side reel 1
Take up by 7. In the process of winding,
The toner 19 adhering to the heat-resistant film 14 is collected by the toner collection tray 20, so that the toner 19 is scattered from the heat-resistant film 14 and drops onto the recording medium 11 and the recording medium 1
It is possible to prevent the image clearly fixed to 1 from being stained.

According to the above construction, since the heat resistant film 14 is not circulated and reused, no special measure for preventing toner adhesion to the heat resistant film 14 is required. Examples of measures for preventing toner adhesion include special coating processing on the surface of the heat resistant film, supply of silicone oil to the surface, setting of a toner remover, and the like. Further, since the heat resistant film 14 is simply collected without a circulation structure, the toner 19 attached to the heat resistant film 14 can be collected more reliably.

These can reduce factors that deteriorate image quality, such as scattering of excess toner, mixing of other toner into an unfixed toner image, and dropping of excess toner onto a fixed image. Further, the structure of the image fixing device is simplified, and the processing steps for preventing toner adhesion to the heat-resistant film are reduced or simplified, which is advantageous in cost.

Although the above-described embodiment is a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

[0023]

As is apparent from the above description, the image fixing device of the electrophotographic image forming apparatus of the present invention supplies a heat-resistant film, heats and pressurizes the supplied heat-resistant film, and then collects the heat-resistant film. Thus, the heat resistant film is conveyed in one direction and heated and pressed. According to this structure, since a new portion of the heat resistant film is always used for image fixing, it is not necessary to take measures to prevent toner adhesion to the heat resistant film. Since the heat-resistant film is not circulated and reused, it is easy to take measures to collect the excess toner attached to the heat-resistant film, and the collection efficiency can be improved. As a result, it is possible to reduce the scattering of the excess toner and the adhesion to the recording medium, and it is possible to reduce the cost and improve the image quality.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image fixing device of an electrophotographic image forming apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of an image fixing device of a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

 11 Heating Element 12 Heating Element Supporting Member 13 Pressure Roller 14 Heat Resistant Film 15 Supply Side Reel 16 Film Conveying Roller 17 Recovery Side Reel 18 Recording Medium 19 Toner

Claims (2)

[Claims] 1. A toner image formed on a recording medium is heated and pressed by stacking a heating element and a heat-resistant film,
In an image fixing device of an electrophotographic image forming apparatus for fixing the toner image to the recording medium, a heat-resistant film supplying means for supplying the heat-resistant film, the heat-resistant film supplied from the heat-resistant film supplying means for heating and An electronic device comprising: a heat-resistant film collecting means for collecting after pressurizing, wherein the heat-resistant film is conveyed in one direction from the heat-resistant film supplying means to the heat-resistant film collecting means, and the heating and pressing are performed. Image fixing device for photographic image forming apparatus. 2. The image fixing device of the electrophotographic image forming apparatus further has a toner collecting means, and the toner falling from the heat resistant film after the heating and pressurizing is collected by the toner collecting means. Claim 1
An image fixing device of the electrophotographic image forming apparatus described.