JPH07319357A - Paper powder removing device - Google Patents

Abstract

PURPOSE:To effectively catch paper powder and talc powder existing in a charged state with a different polarity by use of an electrostatic adhesion force of each brush by constituting the device of the brush which is charged With a positive polarity and the brush which is charged with a negative polarity when they are rubbed with a recording material. CONSTITUTION:A brush roll 11 is slid in contact with the surface of a paper 2 at a speed higher than a speed for feeding the paper 2, and the brush material 9 which is easily charged with the positive polarity and the brush material 10 which is easily charged with the negative polarity are mutually rubbed with the surface of the paper 2. Thus, the talc powder sticking to the surface of the paper 2 is removed by the brush member 9 which is easily charged with the positive polarity, and the paper powder sticking to the surface of the paper 2 is removed by the brush material 10 which is easily charged with the negative polarity. Since the triboelectrification to positive and negative polarities by the combination of two different kinds of brush materials 9 and 10 respectively charged with the positive and negative polarities is effectively used, the paper powder, etc., existing on the surface of the paper 2 can be effectively caught even in the case the components of the paper powder, etc., are charged with either polarity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper dust removing device provided in a paper feeding device of an electrophotographic recording device such as a laser printer, a copying machine and a facsimile.

[0002]

2. Description of the Related Art A paper dust removing device in an electrophotographic recording device or the like includes, for example, a paper feeding roller, a paper conveying roller for rubbing a brush brush or a roll brush,
It is used as a device that abuts a sheet-shaped scraper member or a device that removes paper powder or talc powder by rubbing or contacting the brush-like roll brush directly with a sheet.

On the other hand, the paper sent out from the paper tray is
Due to frictional electrification between sheets and frictional electrification with each member of the sheet conveying path, the sheet is usually charged with positive polarity. However, talc, which is a paper filler, tends to be negatively charged. Therefore, for example, a roll brush that is triboelectrically charged with a negative polarity or a brush-like brush can capture paper dust adhering to the paper surface, but it is difficult to adsorb talc powder. Therefore, it becomes a causative substance that causes image quality defects such as image loss, image blurring, and image deletion when attached to the photoconductor.

The same problem occurs when a bias voltage is applied to the roll brush or brush-like brush.
That is, if you try to remove the talc powder and make the charging property of the brush positive, the paper powder adhering to the paper surface cannot be removed, and this adheres to the photoconductor and reaches the cleaning unit. Cause cleaning failure,
Further, the talc powder contained in the paper powder may cause the above-mentioned image loss, image blurring, and image deletion.

Therefore, in order to improve the above-mentioned poor image quality,
It is necessary to remove both the paper fibers that are easily separated from the paper surface and the talc powder that is easily separated from the surface layer.

[0006]

As means for solving the above problems, for example, JP-A-2-188332, JP-A-59-43973 and JP-A-59-80.
There is a rotating brush disclosed in Japanese Patent No. 327 that removes paper dust or the like mechanically or statically. However, these configurations make the triboelectrification polarity with a mating contact object a specific polarity. As described above, the material is not configured.

Therefore, when attempting to remove paper powder or the like by static electricity, the electrostatic adhesion force is weak, and due to either positive or negative unipolar charging, only one of paper powder or talc powder can be captured. could not. Therefore, only one of the paper powder and the talc powder can be captured. Therefore, in order to remove both the paper powder and the talc powder, a means for rubbing the positively and negatively charged members on the surface of the paper is necessary. Will be needed.

In Japanese Patent Laid-Open No. 3-147648, a bias voltage having a polarity opposite to the electrostatic charge of the paper is applied to a pair of brush rollers arranged so as to rub the front and back surfaces of the paper. Alternatively, the conductive brush is grounded to neutralize and remove the electrostatic charge of the paper, and at the same time, the paper dust is removed by rubbing the brush roller.
This technique is not sufficient to capture both paper and talc powders due to the single polarity.

Further, when a conductive brush is used, it is possible to capture both paper powder and talc powder having electrostatic charges of different polarities, but the electrostatic adhesion force is weak and paper powder, It cannot capture talc powder etc. sufficiently.

FIG. 1 shows the charge polarity and charge of the paper in each part, taking the paper transport path of the printer as an example.
As shown in the above-described example, the paper 2 in the paper cassette 1 is in the transport path, that is, in the transport path that passes through the field roll 3, the registration roll 4, the photoconductor drum 5, and the fixing roll 6 to the paper discharge tray 7. It can be seen that the particles are positively charged.

Further, as shown in Table 1, according to the triboelectrification order, talc powder is more likely to be negatively charged than paper. Positive polarity due to frictional electrification and separation electrification between the sheets immediately after they are sent out, and frictional electrification due to contact when the sheet passes through a metal guide member or a resinous guide member disposed in the sheet conveyance path. It can be seen from the example shown in FIG. 1 that the toner is easily charged to the surface. At that time, it is considered that the talc of the paper filler is negatively charged.

Therefore, in order to prove this, an experiment was conducted using a triboelectrifying roll which was designed to remove paper powder and talc powder only by electrostatic adhesion, and as a result, Table 2
It was verified that the occurrence of deletion (image deletion) is controlled when the charging polarity of the roll is positive as shown in FIG.

From the above, both the paper powder mechanically separated by the paper feed roller and the like on the surface of the paper, the paper fibers which are about to be separated and the talc powder which is easily separated on the surface of the paper are used. In order to capture, it is necessary to bring a plurality of removing members, which are charged in both positive and negative polarities, into sliding contact with the sheet.

[0014]

In order to achieve the above object, a paper dust removing device according to the present invention forms an image by transferring a visible image formed on an image carrier onto a recording material. In a paper dust removing device that is provided on the upstream side of a transfer unit of an image forming apparatus and removes paper dust of the recording material by contacting with the recording material, a brush charged to a positive electrode by friction with the recording material and a negative electrode It is composed of an electrically charged brush.

[0015]

[Working] By rubbing brushes with different properties on the recording material, paper powder and talc powder existing on the surface of the recording material with different charging polarities are effective by the electrostatic adhesion force of each brush. Captured by.

[0016]

EXAMPLE An example of the present invention will be described with reference to FIG. In the explanation of this embodiment, the same members as those of the conventional one shown in FIG. As shown in FIG. 2, one brush roll 11 is provided on the upstream side of the photosensitive drum 5 so as to be in sliding contact with the surface of the paper 2 supplied to the photosensitive drum 5. The frit cover 12 is in contact with the brush roll 11, and the paper dust receiving pan 13 is provided on the lower side.

The brush roll 11 is configured as shown in FIG. 3, and brush materials 9 and 10 made of first and second lace-like woven fabrics made of different materials are alternately wound around the brush shaft in a spiral shape. Is configured. The brush materials 9 and 10 are made of materials in which one is easily charged to the positive electrode and the other is easily charged to the negative electrode due to friction with the contact partner member. Rayon is used as the brush material 9 that easily charges the positive electrode, and tetron is used as the brush material 10 that easily charges the negative electrode.

The frictional chargeability when the surface of the paper 2 is rubbed by the brush roll 11 is as shown in FIG. 4, which shows good frictional chargeability.

Regarding the material and processed shape of the brush, it is desirable to use in the following range in order to prevent the deformation of the thread and the promotion of the generation of paper dust due to the mechanical contact force. Brush single yarn denier: 6-20d Brush pile height: 5-10mm Brush density: 10,000-60,000 / inch ² base cloth lace width: 5-15mm Brush rotation direction: Same as paper running direction

In this structure, as shown in FIGS. 5 and 6, the brush roll 11 is brought into sliding contact with the surface of the paper 2 at a speed higher than the feeding speed of the paper 2. As a result, the brush material 9 that easily charges the positive electrode and the brush material 10 that easily charges the negative electrode alternately rub against the surface of the paper 2. Therefore, FIG.
As shown in FIG. 6, the talc powder 15 adhering to the surface of the paper 2 is removed by the brush material 9 which is easily charged to the positive electrode, and as shown in FIG.
The paper dust 16 adhering to the surface of is removed.

FIG. 7 shows a second embodiment of the present invention. Two brush rolls 1 are provided on the upstream side of the photosensitive drum 5.
The sheets 7 and 18 are arranged in sliding contact with the sheet 2. One of the brush rolls is made of a brush material that easily charges the positive electrode, and the other brush roll is made of a brush material that easily charges the negative electrode. Each brush roll 1
The frit cover 12 and the paper dust receiving pan 13 are provided on the reference numerals 7 and 18.

In the second embodiment, the talc powder and the paper powder adhering to the surface of the paper 2 are removed by the both brush rolls 17 and 18 by the same operation as in the first embodiment.

Further, as a third embodiment, as shown in FIG. 8, a pair of bar brushes 19 and 2 formed by brush-like processing of two types of brush materials which are easily charged to positive and negative polarities respectively.
0 is in the paper transport path on the upstream side of the photosensitive drum 5, and the paper 2
It is provided in sliding contact with the surface of.

Also in this case, as in the first and second embodiments, the talc powder and the paper powder charged on the paper 2 are positively and negatively charged by the sliding contact between the bar brushes 19 and 20. To be removed. In addition, Table 3 shows the deletion generation grade in the bias application roll.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

According to the present invention, the triboelectrification of both positive and negative polarities due to the combination of two kinds of brush materials having different positive and negative polarities of charge is efficiently utilized, and the polarity of the charge such as paper dust is removed. However, the paper dust or the like on the surface of the paper 2 can be efficiently captured.

As a result, as shown in Table 2, as compared with the conventional brush using a triboelectric charging using a single material, the brush using a conductive brush, and the brush applying a bias, as shown in Table 2, talc depletion-generated prints are obtained. As can be seen from the number of sheets, it has a life extension effect of more than double. Further, it can be provided at a lower cost than the bias applying method.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a charging property of a sheet in a sheet conveyance path of a printer.

FIG. 2 is an explanatory diagram showing an embodiment in which the present invention is applied to a paper conveyance path of a printer.

FIG. 3 is a perspective view showing an example of a brush roll.

FIG. 4 is a diagram showing the triboelectrification property of a brush roll formed by combining two types of brush materials.

FIG. 5 is an explanatory diagram showing a principle of removing paper dust and the like with a positive electrode charging brush.

FIG. 6 is an explanatory diagram showing a principle of removing paper dust and the like with a negative electrode charging brush.

FIG. 7 is an explanatory diagram showing an example in which brush rolls are arranged in parallel in a paper conveyance path of a printer.

FIG. 8 is an explanatory diagram showing an example in which brush-like brushes are arranged in parallel on a paper conveyance path of the printer.

[Explanation of symbols]

1 ... Paper cassette, 2 ... Paper, 3 ... Feed roll, 4
... resist roll, 5 ... photoconductor drum, 6 ... fixing roll, 7 ... paper discharge tray, 9, 10 ... brush material, 11,
17, 18 ... Brush roll, 12 ... Frit cover, 13
… Paper dust pan, 15… Talc powder, 16… Paper powder, 19,
20 ... bar brush.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Oike 2274 Hongo, Ebina, Ebina, Kanagawa Fuji Xerox Co., Ltd.Ebina Business Office (72) Inventor, Makoto Sakabebe 2274, Hongo, Ebina, Kanagawa Fuji Xerox Co., Ltd. Ebina Works (72) Inventor Masahiro Sato 2274 Hongo, Ebina City, Kanagawa Fuji Xerox Co., Ltd.Ebina Works

Claims (1)

[Claims] 1. A recording medium, which is provided on the upstream side of a transfer portion of an image forming apparatus for forming an image by transferring a visible image formed on an image bearing member onto a recording material, and contacts the recording material to record the image. A paper dust removing device for removing paper dust of a material, comprising a brush charged to a positive electrode and a brush charged to a negative electrode by friction with a recording material.