JPH09197934A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent staining on the rear surface of a transfer paper caused by carrying belts by providing a cleaning means for cleaning the carrying belts. SOLUTION: A cleaning far brush 20 is provided on the side of the fixing roller 5 of each carrying belt 2. The far brush 20 is constituted of a roller-like core metal, a base cloth wound on the core metal and looplike or straight fur interwoven with the base cloth and located to bring the fur into contact with the carrying belts 2. The fur brush 20 is provided to correspond to all of plural carrying belts 2 and can clean the carrying belts 2 in all the sizes of the transfer papers capable of passing through, to prevent the occurrence of the staining on the rear surface of the transfer paper caused by the fact that an uncleaned part remains when the transfer paper having a maximum paper passing width passes through. The fur brush 20 is driven to rotate in a fixed direction by a driving means, so that the fur rubs the surfaces of the carrying belts 2, to scrape/remove toner, paper powder, etc., stuck onto the surfaces of the belt 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a printer or the like for performing electrostatic transfer, and more particularly to an improvement of a transfer paper conveying apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus of this type, a transfer belt that transfers image information of a photoconductor onto a transfer paper and electrostatically conveys the transfer paper, and a transfer belt. A transfer belt is provided which connects between the entrance of a fixing roller for fixing the image information transferred on the paper and the transfer belt, and the transfer belt and the transfer belt have the same resistance value.

However, since the transfer belt is in contact with the photoconductor, the background toner on the photoconductor between the transfer sheets is transferred to the transfer belt. Since the transfer belt is equipped with a cleaning device, the transfer belt surface is cleaned, but toner that has entered the transfer belt such as cracks cannot be completely cleaned and remains on the transfer belt. There is. The toner remaining on the transfer belt adheres to the back side of the transfer paper. Therefore, an object of the present invention is to prevent the back surface of the transfer paper from being contaminated by the conveyor belt.

[0004]

According to a first aspect of the present invention, there is provided a transfer belt for transferring image information of a photoconductor onto a transfer paper, and for transferring the transfer paper by electrostatic attraction. An image forming apparatus having a conveyor belt connecting an entrance of a fixing roller for fixing the image information transferred on the transfer paper and the transfer belt, and having the same resistance value as the conveyor belt and the transfer belt. In the above, a cleaning means for cleaning the conveyor belt is provided.

The image forming apparatus according to the second aspect is characterized in that the length of the cleaning means is equal to or larger than the maximum sheet passing width of the transfer sheet.

In the image forming apparatus according to the third aspect, the cleaning means is a fur brush.

In the image forming apparatus according to the fourth aspect, the cleaning means is a blade.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a structure around a transfer / conveying belt device of an image forming apparatus according to the present invention, and FIG. 2 is a plan view of the same. In this image forming apparatus, the transfer / transport belt of the transfer / transport device is divided into a transfer belt 1 and a transport belt 2. A plurality of conveyor belts 2 are arranged in parallel so as to correspond to the maximum sheet passing width.

The operation of the image forming apparatus of this embodiment will be outlined. The transfer belt 1 transfers an image on the photoconductor 3 to a transfer paper (not shown), and the transfer paper on which the image is transferred is attracted by the electrostatic attraction force of the transfer belt 1 and conveyed. The transferred transfer paper is separated by the curvature of the drive roller 4 of the transfer belt 1, and is further transferred to the fixing roller 5 by the transfer belt 2. At this time, the transfer sheet conveyed by the conveyor belt 2 is sucked by the suction fan 6 installed below the conveyor belt 2 and adheres to the upper surface of the conveyor belt 2 so that the fixing roller 5
Is transported to the entrance to.

At this time, the transfer belt 1 and the conveyor belt 2 are arranged so that the rear end of the transfer paper passes through the nip portion between the photoconductor 3 and the transfer belt 1 and then the front end of the transfer paper enters the fixing roller 5.
Even when the linear distance between the fixing roller 5 and the nip portion between the photoconductor 3 and the transfer belt 1 is less than the maximum transfer paper size, the conveyance from the nip portion between the photoconductor 3 and the transfer belt 1 to the fixing roller 5 is performed. Ensure that the path is larger than the maximum transfer paper size.

The transfer belt 1 and the conveyor belt 2 are driven by transmitting a driving force from a main motor (not shown) to the conveyor belt drive gear 7 to drive the conveyor belt 2 in the direction of the arrow in the figure, and also from the main motor. The force is transferred to the transfer belt drive gear 1 via the transfer belt driven pulley 10 and the timing belt 9 via the transfer belt driven gear 10 and the idler gear 11.
2, the transfer belt drive roller 4 is rotated in the direction of the arrow in the figure, and the transfer belt 1 is driven in the direction of the arrow in the figure.

Regarding the surface resistivities of the transfer belt 1 and the conveyor belt 2, if the surface resistivities of the transfer belt 1 and the conveyor belt 2 are different, an abnormal discharge occurs at the time of separating the transfer paper, and the transferred image is disturbed. The surface resistivities are made equal to prevent abnormal discharge during separation, and the transfer paper is separated and conveyed from the transfer belt 1 in a state where the transfer image is stable.
For example, in both the transfer belt 1 and the conveyor belt 2, a chloroprene rubber having a surface resistivity of 1 × 10 ⁷ to 1 × 10 ⁹ Ω is used for the rubber layer and a surface resistivity of 1 × 10 ⁹ to 1 × 10 for the coat layer.
^{Use 12} Ω polyvinylidene fluoride.

Fur brushes 20 for cleaning are provided on the fixing roller 5 side of each of the conveyor belts 2. FIG.
Is an enlarged side view around the fur brush 20, and FIG. 4 is a perspective view of the same. The fur brush 20 is composed of a roller-shaped core metal 21, a base cloth 22 wound around the core metal 21, and a loop-shaped or straight hair-shaped hair body 23 woven into the base cloth 22, and the hair body 23 is shown in the figure. As shown in FIG. The fur brush 20 includes a plurality of conveyor belts 2.
The transfer belt 2 can be cleaned for all sizes of transfer paper that can be passed, and an uncleaned portion does not remain when the transfer paper having the maximum paper passage width is passed, so that the back surface of the transfer paper is not stained. Is done.

The fur brush 20 is rotationally driven in the clockwise direction in FIG. 3 by a driving means (not shown), and the hair 23 rubs against the surface of the conveyor belt 2 so that toner attached to the surface of the conveyor belt 2 and the like. Remove paper dust by scraping.

5 and 6 show an embodiment in which a blade is used for cleaning the conveyor belt. The cleaning blade 30 includes a blade 31 and a blade holder 32. The blade holder 32 is positioned diagonally below the conveyor belt drive pulley 8 in FIG. 5, and the tip of the blade 31 slides on the surface of the conveyor belt 2. By rubbing, the toner adhering from the back surface of the transfer paper and the paper dust generated from the transfer paper are scraped off. This blade type cleaning means does not require a drive mechanism unlike the fur brush type, so that the structure can be simplified accordingly.

[0016]

The image forming apparatus according to the present invention has the cleaning means for cleaning the conveyor belt.
There is an effect that it is possible to prevent the back surface of the transfer paper from being soiled by the transport belt.

In the image forming apparatus according to the second aspect of the present invention, since the conveyor belt and the cleaning means are longer than the maximum sheet passing width, it is possible to prevent the transfer belt from being contaminated by the conveying belt for all transferable sheets. effective.

According to another aspect of the image forming apparatus of the present invention, by using the fur brush as the cleaning means, the toner on the conveyor belt is scraped off, and at the same time, the dust of the transfer paper is scraped off by the fur brush hairs. Therefore, there is an effect that it is possible to prevent the fixing performance from being deteriorated by the paper dust.

According to the image forming apparatus of the fourth aspect, by using the blade as the cleaning means, there is an effect that the cleaning means can be provided at a low cost with a simple structure without the need for a drive system.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration around a transfer / conveying belt device of an image forming apparatus according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is an enlarged side view around the fur brush.

FIG. 4 is a perspective view around the fur brush.

FIG. 5 is an enlarged side view around a cleaning blade that replaces the fur brush.

FIG. 6 is a perspective view of the same.

[Explanation of symbols]

 1 Transfer Belt 2 Conveyor Belt 3 Photoconductor 4 Transfer Belt Drive Roller 5 Fixing Roller 6 Suction Fan 7 Conveyor Belt Drive Gear 8 Conveyor Belt Drive Pulley 9 Timing Belt 10 Conveyor Belt Driven Gear 11 Idler Gear 12 Transfer Belt Drive Gear 20 Fur Brush 21 Core metal 22 Base cloth 23 Hair body 30 Cleaning blade 31 Blade 32 Blade holder

Claims (4)

[Claims] 1. Transferring image information of a photoconductor onto a transfer paper,
And a transfer belt that electrostatically conveys the transfer paper, and a conveyance belt that connects between the entrance of a fixing roller that fixes the image information transferred onto the transfer paper and the transfer belt.
Further, in the image forming apparatus in which the resistance value of the transfer belt is equal to that of the transfer belt, the image forming apparatus includes a cleaning unit for cleaning the transfer belt. 2. The image forming apparatus according to claim 1, wherein the length of the cleaning means is equal to or larger than the maximum sheet passing width of the transfer sheet. 3. The image forming apparatus according to claim 1, wherein the cleaning unit is a fur brush. 4. The image forming apparatus according to claim 1, wherein the cleaning unit is a blade.