JPS60150064A - Electrically conductive brush of copying machine - Google Patents

Abstract

PURPOSE:To prevent deterioration of toughness and uniformly charging performance, etc. for a long term, by coating the surface of each fiber contg. a dispersed conductive material with an elastic rubber layer and using these conductive fibers to prepare a conductive brush for use in an electrophotographic copying machine. CONSTITUTION:A conductive material 9, such as carbon, into nylon fibers or the like to form conductive fibers 8, and their surfaces are coated with an elastic material layer 10, preferably, made of silicone rubber. A conductive brush 3 made of these fibers 8 are arranged rotatably near a photosensitive body 1, and the brush 3 is electrostatically charged. The surface of the photosensitive body 1 is rubber with the brush 3, charge is transferred to the body 1, and it is charged. Since the surfaces of the fibers 8 are coated with the elastic rubber layer 10, the brush is not deteriorated in toughness for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a four-polarity brush used in a charging device or a cleaning device of an electronic copying machine.

Prior Art Conventionally, a corona charging method using a corona charger has been widely used to charge the photoreceptor in electronic copying machines, but the corona charger is dangerous because it uses high pressure, and The drawback is that it generates a large amount of ozone when charged, which can damage other parts.

Therefore, a contact charging method using a brush charger has been proposed as an alternative to the corona charging method, but this method has the advantage of being safer because it uses a lower voltage than the corona charging method, and generates extremely little ozone. . On the other hand, plated fibers, metals, or tetraelectric fibers are generally used as the brush of this brush charger, but since the brush fibers constantly rotate in contact with the surface of the photoreceptor and charge the photoreceptor,
There are drawbacks such as damage to the surface of the photoreceptor and conversely, the brush fibers become flattened, resulting in poor charging characteristics and, as a result, the quality of copies is adversely affected.

OBJECTS OF THE INVENTION It is an object of the present invention to provide brush fibers for a brush charger that can eliminate the above-mentioned drawbacks of the brush charger, have uniform charging properties, and maintain good copy image quality over a long period of time.

Structure of the Invention The conductive brush for the copying machine of the present invention is characterized in that it is made of conductive fibers in which a tetraelectric substance is dispersed, and the surface of the fibers is coated with a rubber elastic layer.

The present invention will be described in detail below based on the accompanying drawings. 1st
FIG. 1A is a schematic diagram of a brush charger, in which a brush charger 2 is provided so as to come into pressure contact with a photoreceptor 1. FIG. Conventional brush chargers are in constant contact with the photoreceptor, so the first
As shown in Figure (b), the brush fibers become sagging A. FIG. 2 is a cross-sectional view of a brush charger using conductive fibers, in which conductive fibers 3 are flocked on a base fabric 4.
A conductive back coat layer 5 is provided on the back side, and this is wound around the paper tube 7 by the adhesive force of the adhesive layer 6.

Figures 3 (a) and (b) are cross-sectional views of conventional conductive fibers, which are made conductive by dispersing conductive substances such as carbon 9 into fibers 8, but depending on the dispersion method, (a) % (b
), etc., with different structures are swept away. Examples of conductive fibers include acrylic fibers (5A-7 manufactured by Toshi Corporation), nylon fibers (Beltron manufactured by Kanebo Corporation), and rayon fibers (Shikku manufactured by Unitika Corporation). It is conductive.

FIG. 41 shows the basic structure of the present invention, in which the surface of the aforementioned 411L fiber 8 is coated with a rubber elastic layer 10. In this case, RTV (room temperature vulcanizable silicone rubber), which can be spray coated, is used as the Nocom elastic layer (Toshiba Silicone Co., Ltd.).
SE-3031RTV, KE45 manufactured by Shin-Etsu Silicone ■
SRTV, etc.).

In the electronic copying machine, a brush-type charger 2 is rotatably arranged near the photoreceptor 1, and the conductive brush 3 is charged by means not shown. When the charger 2 rotates, the conductive brush 3 rubs the surface of the photoreceptor 1, and the charges on the brush 3 move to the photoreceptor 1, so that the photoreceptor 1 is charged. By covering the outer periphery of the fibers 8 with the rubber elastic layer 10, the conductive brush 3 has elasticity, so that the brush 3 will not wear out even if it is rubbed against the photoreceptor 1 for a long time.

FIG. 6 shows the results of a brush fatigue test using the conductive brush of the present invention in comparison with a conventional example. As can be clearly seen from this figure, as the number of copies increases in the conventional conductive brush, the amount of sag increases significantly, but the conductive brush provided with the rubber elastic layer of the present invention increases the number of copies per copy. Even if it increases, the amount of wear is extremely small.

From this, it can be seen that the conductive brush of the present invention has characteristics far superior to those of the conventional brush.

What has been explained above is a conductive brush for a charger, but there are also other brushes such as cleaning brushes, which are inconvenient if sagging occurs.If a rubber elastic layer is provided around the outer periphery of the brush, the brush will be reinforced and sag may occur. There isn't.

Effects of the Invention According to the present invention, unlike conventional brush chargers, the fibers do not deteriorate prematurely, and deterioration in charging uniformity can be prevented over a long period of time, resulting in excellent copy image quality.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic diagram showing the arrangement of the brush charger and the photoreceptor, and FIG.
A side view of the device, Figure 2 is a partial sectional view of the brush charger, and Figure 3 is a partial cross-sectional view of the brush charger.
Figures Ca) and (b) are cross-sectional views of conductive fibers, Figure 2 is a cross-sectional view of conductive fibers used in the present invention, Figure 2 is a comparison of the characteristics of conventional conductive brushes and the conductive brush of the present invention. This is the graph. Symbols in the figure: 1... Photoreceptor; 2... Brush charger; 3... Conductive brush: 4... Base fabric; 5... Back coat layer; 6
... Adhesive layer; 7... Paper tube; 8... Fiber; 9...
Carbon; lO...Rubber elastic body layer; A...Settling amount.

Claims (1)

[Claims] A conductive brush for a copying machine, characterized in that it is made of conductive fibers in which a conductive substance is dispersed and the surface of the fibers is coated with a rubber elastic layer.