JPS6032073A - Brush electrostatic charger - Google Patents

Abstract

PURPOSE:To improve electrostatic charging characteristics of a body to be charged by weaving contacts and constituting a carried underlying material by conductive fibers having the same or less resistance value as that of the contacts. CONSTITUTION:An electrostatic charging roller consists of a rotatable roller body 1 and a contact body 30 whose back is adhered to the whole main surface of the roller body 1 through an insulating adhesives layer 20. The contact body 30 consists of the underlying material layer 60 formed by a textile composed of warp and weft made of conductive fibers and brush-like contacts 7 made of carbon-dispersed acrylic fiber an woven into the layer 60. Since the underlying material 60 of the roller is also constituted of the conductive fiber, an electric field is expanded in the plane direction extremely efficiently and the contacts 7 apply uniform charge to the photosensitive body precisely. Consequently, stable charging characteristics can be maintained and the quality of a copied picture is extremely improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a T-brush charging device, and in particular to a brush used in processes such as charging a photoreceptor (photoconductor layer) in an electronic 4-photo copying machine. This invention relates to a charging device.

[Prior art]

In electrostatic electrophotographic apparatuses, a corona charging device is often used as a means for applying a uniform charge to the surface of a photoreceptor.

However, since corona charging devices use high voltage,
In addition to being dangerous, corona discharge characteristics are subject to large fluctuations due to external conditions (pressure, temperature, humidity, ventilation conditions), and the ozone generated during discharge poses the problem of damaging peripheral equipment. was.

In order to eliminate these disadvantages, attempts have been made in recent years to develop a brush-type charging electrode using a contact charging method instead of the conventional corona charging device.

A conventional brush charging roller for contact charging has a roller body (base) capable of rotating AF, as shown in FIG. 1 showing a part of its cross section and FIG. 1 and a contact body 3 adhered to the entire main surface of the roller body with an insulating adhesive 2 interposed therebetween. As shown in a perspective view in FIG. 3, this contact body 3 includes a base layer 6 made of a woven fabric of warp threads 4 and weft threads 5 made of non-conductive fibers, and a brush made of conductive fibers woven into the base layer 6. A contact element 7 having a shape of 1.5 mm is formed by fixing the back surface of the contact element 7 with a back coat layer 8 made of conductive paste.

In this device, the current supplied to the base IK passes through the back coat layer 8 and flows to the contact 7, and this contact 7 supplies charges to the photoreceptor, which is the object to be charged.

By the way, this contactor 7 is made of, for example, carbon-dispersed acrylic fiber made by Toshi Co., which is commonly referred to as 5A-7, carbon-dispersed nylon fiber made by Kanebo Co., Ltd., which is commonly known as Beltron, and Unitika Co., Ltd., which is commonly known as Ledge. However, the warp yarns 4 and the weft yarns 5 constituting the base layer are made of non-conductive fibers such as spun, tetoron, and polypropylene, respectively, and The spread of the electric field in the horizontal direction (°C in Figure 1) is uneven, resulting in poor charging characteristics, and images formed by copying machines using such charging rollers are said to have uneven image quality. I had a problem.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a charging device that can uniformly and stably charge and maintain the surface of a charged body (photoreceptor).

[Structure of the invention]

The brush charging device of the present invention has a contactor woven into it, and the supporting base (fabric body consisting of warp and weft threads) is made of conductive fibers having a resistance value equal to or lower than that of the armature. This is an attempt to improve the charging characteristics by ensuring the spread of the electric field in the plane direction.

〔Example〕

The charging roller according to the embodiment of the present invention has a rotatable roller main body (base), as shown in FIG. The contact body 30 is attached to the entire main surface of the roller body through an insulating adhesive layer 20 made of nylon, acrylic, etc., so that the back surface is fixed to the entire main surface of the roller body. This contact body includes a base layer 60 formed of a woven body of warp threads 40 and weft threads 50 made of conductive fibers manufactured by Nippon Bige Co., Ltd., commonly known as Thunderon, and a 5A-7 base layer 60 woven into the base layer 60. It consists of a brush-like contactor 7 made of carbon-dispersed acrylic fiber manufactured by Toshi Co., Ltd., and its woven form is the same as that of the conventional example shown in FIG.

When copying is performed using conventional equipment, one copy of Japan Industrial Standards Column A No. 4 paper, which is considered to be a charging failure, is produced.
According to this roller, the area ratio of "white spots" was approximately 159C, but since the base is also made of conductive fibers, the spread of the electric field in the plane direction is extremely good, and the contactor is By reliably applying a uniform charge to the photoreceptor, it is possible to maintain stable charging characteristics, and the image quality of each copy is greatly improved.

In addition, voltage can be applied directly to the base, and the contact body can be simply adhered to the surface of the base l without the need for a conductive back coat layer as in conventional examples. The adhesive used for this purpose only needs to be selected from those with good adhesive properties, and the adhesive strength of the contact body can be increased, thereby improving the durability of the charging roll.

In the examples, Thunderon (manufactured by Nippon Bimo Co., Ltd.), which is a fiber impregnated with conductive particles, was used for the warp and weft threads of the base. Fibers coated to make them conductive, conductive fibers such as P-4 (manufactured by Asahi Kasei Co., Ltd.) or metal fibers commonly known as Naslon, are fine as long as they can form a conductive base layer. Needless to say.

〔Effect of the invention〕

As explained above, according to one aspect of the present invention, by composing the base on which the contact is woven and fixed with a conductive material, it is possible to ensure the spread of the electric field and obtain uniform and stable charging characteristics. can.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a part of the cross section of a conventional charging roller, FIG. 2 is a sectional view taken along line A-A in FIG. The figure shows a part of the cross section of the charging roller according to the embodiment of the present invention, and FIG. 5 is a sectional view taken along line BB in FIG. 4. l...Roller body, 2.20...Adhesive layer, 3.
30... Contact body, 4, 40... Warp, 5.50.
...Weft, 6゜60... Base layer, 7... Contact, 8
...Back coat layer. Applicant's agent Takahisa Kimura A Figure 1 Figure 2 Figure 4 Figure 5

Claims (3)

[Claims] (1) A roller body, a base layer made of a woven fabric adhered to the entire main surface of the roller body, and conductive contacts woven into the base layer to form a brush-like nap. 1. A brush charging device comprising: a brush charging device characterized in that the fabric body is made of conductive fibers; (2) The brush charging device according to claim (1), wherein the contactor and the fabric body are made of fibers covered with a polymer trap containing conductive particles. (3) The brush charging device according to claim (1), wherein the contactor and the fabric body are made of fibers impregnated with conductive particles.