JPH05257405A - Fixing device for electrophotographic method image forming device - Google Patents

Abstract

PURPOSE:To prevent soiling of a backside of a recording body by cleaning a pressure roller and eliminating ground fogging toner. CONSTITUTION:Unfixed image transferred on a transfer fixing belt 4 by a transfer electrostatic charger 20 is fed between a heating roller 5 and a pressure roller 12 of the fixing device 21 along with the rotation of the transfer belt 4 and fixed to a recording body 6. When the recording body 6 is not passed by the fixing device 21, the ground fogging toner stuck to the pressure roller 12 is eliminated by a cleaning felt 10 abutted to a pressure roller 12 by a spring 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to a fixing device.

[0002]

2. Description of the Related Art FIG. 4 is a schematic sectional view of a conventional electrophotographic image forming apparatus. In the electrophotographic image forming apparatus 1, a paper feed cassette 7 containing a recording body 6 is incorporated. Inside the electrophotographic image forming apparatus 1, a paper feed cassette 7 is provided with a conveyance path 8a for recording bodies, and subsequently, a conveyance path 8b is arranged. Further, there is a portion called an image forming process in the upper part of the image forming apparatus, and the photosensitive drum 19 is arranged in the center thereof, and the cleaner 2, the charging roller 18, the exposing device 17, the developing device 16,
The transfer charger 20 is arranged in contact with or in the vicinity of the transfer charger 20, and an image is formed at this portion to form an unfixed image on the transfer fixing belt 4. The transfer-fixing belt 4 is stably rotated in the direction of arrow a by the drive rollers 3a and 3b, the nip conveyance of the heating roller 5 and the pressure roller 12 of the fixing device 21, and the tension roller 14, and the unfixed image is transferred to the transfer-fixing belt 4. And is fed between the heating roller 5 and the pressure roller 12 of the fixing device 21. Recorded material conveying path 8
The recording medium is fed from b, and the unfixed image on the transfer fixing belt 4 is fixed to the recording medium by the heat of the heating roller 5 and the pressure between the pressure roller 12 and the heating roller 5. After that, the recording medium 6 on which the image is fixed is conveyed through the recording medium conveying path 8c and is discharged onto the abolished tray 13.

[0003]

The fixing device of the above-described conventional electrophotographic image forming apparatus has a drawback that the back surface of the recording medium is soiled because it does not have a cleaning means for the pressure roller. .. That is, the toner 1 in the developing device 16
Although the surface of the photosensitive drum 19 and the surface of the photosensitive drum 19 are charged to the same potential, a phenomenon in which the toner 15 adheres to the photosensitive drum 19 in a minute amount (hereinafter referred to as background fog) inevitably occurs. The toner of this background fog is the photosensitive drum 1.
8 through the transfer / fixing belt 4, the recording medium is fixed to the fixing device 21.
When the recording medium is not passed through the fixing device, it is fixed on the recording medium and discharged together with the recording medium. When the toner of the background fog is accumulated on the pressure roller in this manner, the back surface of the recording body is finally soiled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing device for a book-type photographic image forming apparatus which removes toner adhering to the pressure roller of the fixing device and prevents the back surface of the recording medium from being soiled.

[0005]

A fixing device for an electrophotographic image forming apparatus according to a first aspect of the present invention includes a fixing device including a heating roller and a pressure roller, and sucks and conveys a recording medium, An unfixed image is formed on the transfer-fixing belt through an image forming process, and thereafter, recording is performed by the heating roller that rotates by receiving a driving force from a driving source and a pressure roller that rotates by being pressed against the heating roller. In a fixing device of an electrophotographic image forming apparatus that holds and conveys a body to fix an unfixed image on the recording body, a cleaning felt for cleaning the pressure roller is provided, and the cleaning felt is pressed by an elastic body. The pressure roller is cleaned by pressing it against the roller.

A fixing device for an electrophotographic image forming apparatus according to a second aspect of the present invention is provided with a cleaning paper roll and a winding roll for winding the cleaning paper on the fixing device, and the winding roll is for cleaning. When the paper is rolled up, the cleaning paper contacts the pressure roller to clean the pressure roller.

According to a third aspect of the present invention, there is provided a fixing device for an electrophotographic image forming apparatus, wherein the fixing device comprises a cleaning blade and a cleaner casing, and the cleaning blade is brought into contact with the pressure roller to apply the pressure. The toner adhering to the pressure roller is peeled off, the pressure roller is cleaned, and the peeled toner is stored in the cleaner case.

[0008]

The present invention will be described below with reference to the drawings. FIG. 2 is a schematic cross-sectional view of an electrophotographic image forming apparatus showing an embodiment of the first invention of FIG. 1. The electrophotographic image forming apparatus 1 incorporates a paper feed cassette 7 containing a recording body 6. Inside the electrophotographic image forming apparatus 1,
A conveyance path 8a for the recording medium is arranged following the paper feed cassette 7, and a conveyance path 8b is arranged following it. Further, there is a portion called an image forming process in the upper part of the image forming apparatus, and a photosensitive drum 19 is arranged in the center of the portion. The charging device 20 is arranged in contact with or in the vicinity of the charging device, and an image is formed in this portion to form an unfixed image on the transfer fixing belt 4. Transfer fixing belt 4
Is stably rotated in the direction of arrow a by the drive rollers 3a and 3b, the nip conveyance of the heating roller 5 and the pressure roller 12 of the fixing device 21, and the tension roller 14, and the unfixed image is fixed together with the rotation of the transfer fixing belt 4. It is fed between the heating roller 5 and the pressure roller 12 of the device 21. The recording medium is fed from the recording medium conveying path 8b to the heating roller 5
The heat and the pressure between the pressure roller 12 and the heating roller 5 fix the unfixed image on the transfer fixing belt 4 to the recording medium. After that, the recording medium on which the image is formed is conveyed through the recording medium conveying path 8c and is discharged onto the paper discharge tray 13.

In this embodiment, the cleaning felt 10 for cleaning the pressure roller 12 of the fixing device 21 is disposed under the pressure roller 12 so as to abut against the pressure roller 12, thereby removing the stain on the back surface of the recording medium. To do. That is, the toner of the background fog that occurs even when the toner 15 in the developing device 16 and the surface of the photosensitive drum 19 are charged to the same potential is the pressure roller 12 when the recording medium does not pass through the fixing device. The cleaning felt 10 is brought into contact with the pressure roller 12 by the spring 21,
The toner of the background fog adhering to the pressure roller 12 is removed by the cleaning felt 10.

FIG. 2 is a schematic sectional view of an electrophotographic image forming apparatus showing an embodiment of the second invention of the present invention. Since the cleaning paper 28 taken up from the cleaning paper roll 23 by the take-up roll 22 is in contact with the pressure roller 12, it adheres to the pressure roller 12 through the same process as in the above-described first embodiment of the invention. The toner is cleaned with the cleaning paper 28.

FIG. 3 is a schematic sectional view of an electrophotographic image forming apparatus showing an embodiment of the third invention of the present invention. The pressure roll 1 is processed in the same manner as in the first embodiment of the invention described above.
The toner adhering to the cleaning roller 2 is scraped off from the pressure roller 12 by the cleaning blade 25.
Stored in 4.

[0012]

As described above, the present invention cleans the pressure roller 12 by pressing or abutting the cleaning roller, the cleaning paper, the cleaning blade, etc., on the pressure roller 12 of the fixing device. It has the effect of preventing stains.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an electrophotographic image forming apparatus showing an embodiment of a first invention of the present invention.

FIG. 2 is a schematic sectional view of an electrophotographic image forming apparatus showing an embodiment of the second invention of the present invention.

FIG. 3 is a schematic sectional view of an electrophotographic image forming apparatus showing an embodiment of a third invention of the present invention.

FIG. 4 is a schematic sectional view of a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

 1 Electrophotographic Image Forming Apparatus 2 Cleaner 3a Drive Roller 3b Drive Roller 4 Transfer Fixing Belt 5 Heating Roller 6 Recording Body 7 Paper Cassette 8a Conveying Path 8b Conveying Path 8c Conveying Path 9 Controller 10 Cleaning Felt 11 Spring 12 Pressure Roller 13 Paper discharge tray 14 Tension roller 15 Toner 16 Developer 17 Exposure device 18 Charging roller 19 Photosensitive drum 20 Transfer charger 21 Fixer 22 Winding roll 23 Cleaning paper roll 24 Cleaner case 25 Cleaning blade 28 Cleaning paper

Claims (3)

[Claims] 1. A fixing device including a heating roller and a pressure roller is provided, a recording medium is sucked and conveyed, an unfixed image is formed on a transfer fixing belt through an image forming process, and then a driving source is used. An electrophotographic image forming apparatus for sandwiching and transporting a recording medium by the heating roller that rotates by obtaining a driving force and a pressure roller that is pressed against the heating roller and is driven to rotate, and fix an unfixed image on the recording medium. In the fixing device described above, an electrophotographic image forming apparatus characterized in that a cleaning felt for cleaning the pressure roller is provided, and the cleaning felt is brought into pressure contact with the pressure roller with an elastic body to clean the pressure roller. Fixing device fixing device. 2. The fixing device is provided with a cleaning paper roll and a take-up roll for taking up the cleaning paper, and when the take-up roll takes up the cleaning paper, the cleaning paper is applied to the pressure roller. A fixing device for an electrophotographic image forming apparatus, which is in contact with and cleans the pressure roller. 3. The fixing device includes a cleaning blade and a cleaner case, and the cleaning blade is brought into contact with the pressure roller to remove toner adhering to the pressure roller to clean the pressure roller. A fixing device for an electrophotographic image forming apparatus, wherein the peeled toner is housed in the cleaner case.