JPS5961858A - Electrostatic charger and destaticization device for electrostatic recording - Google Patents

Abstract

PURPOSE:To lower an applied voltage and to improve the stability and uniformity of electrostatic charger and destaticization by using ferromagnetic metallic fluid as a medium for charge supply, and bringing it into direct contact with the surface of an insulator to be charged or discharged. CONSTITUTION:Pointed magnetic bodies 2 and 2 are attached to both ends of a magnet 1 opposite to each other so that their tips have a narrow gap, which is filled with ferromagnetic metallic fluid 3 such as mercury. Further, the magnet 1 is made rotatable and when an electrode is detached, the metallic fluid is prevented from flowing out and scattering. The electrode 21 constituted as mentioned above is impressed with a voltage from a power source 23 and the electrode 21 is in contact with the surface of the insulator 22 while using the ferromagnetic metallic fluid 3 as the medium. Thus, charges are transferred by the direct contacting between the ferromagnetic metallic fluid and insulator, so the electrostatic charge and destaticization are performed stably and uniformly and the same charges are transferred at a lower voltage than that of a corona method, increasing the speed of the electrostatic charge or destaticization.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel charging and removing Wl device used in electrostatic recording, and more specifically, to a novel charging and removing Wl device that is capable of stably and uniformly charging an insulator and quickly removing static electricity. This invention relates to a simple charging and neutralizing device.

In the electrostatic recording method in which an electrostatic latent image is formed on an insulator, it is an essential technique to apply a charge of a predetermined potential to the insulator and remove this charge as necessary. For this purpose, generally a thin electrically conductive wire is stretched near the surface of the insulator to be charged or neutralized, and a high voltage of several gigavolts is applied to this wire to generate a °C corona discharge and apply an electric charge to the insulator. A so-called corona discharge method is used to neutralize the existing electric charge. A so-called fur brush method has also been proposed in which the surface of the insulator is rubbed with fur or the like to generate frictional electrification.

However, since the corona discharge method performs discharge through the air, it is difficult to stably charge an insulator with a constant potential, and there are also problems with the uniformity of charging within one plane. In addition, there are other undesirable drawbacks, such as the need for a high-pressure m source, which is dangerous and increases the size of the device, and light-years of ozone, which is considered to be harmful, when discharged in the air. In addition, the fur brush method is unstable due to hair wear and tear.
Due to drawbacks such as the large size of the device, it has hardly been put into practical use.

An object of the present invention is to provide a small and simple charging or static eliminator that can stably and uniformly charge or remove a predetermined potential from an insulator using a much lower voltage power source than the corona discharge method. It is about providing.

A feature of the present invention is that a ferromagnetic metal fluid is used as a charge supply medium, and it should be charged or neutralized! ! ! This was achieved by means of a device that was brought into direct contact with the surface of the edge. According to the above device, charge is exchanged through direct contact between the ferromagnetic metal fluid and the insulator, so charging and neutralization can be performed extremely stably and uniformly, and the applied voltage can also be applied at the same rate as the corona method. It is possible to apply an equivalent charge, and unlike the case of corona discharge, there is virtually no restriction on the amount of harmful particles supplied, so it is possible to charge or remove static electricity from an insulator at a high speed. A typical ferromagnetic metal fluid is one in which iron particles are dispersed in mercury, as described in the magazine "Industrial Materials", Vol. 7, No. 7 (July 1982), page A. manufactured by such a method.

Mercury, which is a metallic liquid, has good drowsiness conductivity and has no adhesion to other materials, making it suitable as a medium for contact charging and neutralization. When trying to charge or remove static electricity from a moving insulator, it is difficult to hold mercury in an appropriate position, and its use is impractical when considering the toxicity of mercury when it spills and scatters. Met.

The present invention uses a liquid metal such as mercury made into a ferromagnetic fluid, which is held in an electrode section by magnetic force and placed in contact with an insulator to be charged or neutralized.

Hereinafter, the content of the present invention will be specifically explained using the drawings.

FIG. 1(A) is a schematic cross-sectional view of a band-shaped or non-N electrode according to the present invention. As shown in the figure, a magnetic material 2.2' with a shiny tip is attached to the r7fiJ pole of the magnet l so that the tips thereof face each other so as to form a narrow gap, and the narrow gap is filled with a ferromagnetic metal fluid 3. In the narrow gap, an extremely strong magnetic field is formed because the sharp magnetic bodies are placed very close to each other. Therefore, the ferromagnetic metal fluid 3 is strongly held here.

In addition, when the magnet 1 is made rotatable and the electrode is removed, the metal fluid 3 is attracted by the magnet 1 and is contained in the cavity inside the ml pole by setting the state as shown in Fig. 1 (B). Prevents spillage and scattering of liquids containing mercury and allows safe handling. Also, if you are moving it, seal the gaps with tape, etc.).

FIG. 2(A) is a conceptual diagram when charging or neutralizing an insulator using this electrode, and 2] is the above electrode, 2
Reference numeral 2 denotes an insulator to be charged or neutralized, which moves in the direction of the arrow. A voltage is applied to the electrode 21 by a power source Z3, and the electrode 21 is in contact with the surface of the insulator using the ferromagnetic metal liquid 3 as a medium, as shown in FIG. 2(B). 2
4 is a grounding roller. In the figure, the symbol 10 is used to represent charging, but it is of course possible to give a charge of 1 by changing the sign of the applied voltage as necessary.

FIG. 3 is a schematic diagram of an embodiment in which a charging device according to the present invention is attached to an electrostatic recording device using a photoreceptor having photoconductivity as an insulator.

31 is a selenium-tellurium photoreceptor layer;
[Rotate in the direction of the arrow using an aluminum drum with a diameter of 120 ynx. Reference numeral 33 denotes a charging electrode according to the present invention, which is in contact with the surface of the photoreceptor 320 through a ferromagnetic metal fluid 34. The ferromagnetic metal fluid used was one in which fine iron particles were dispersed in mercury, and its saturation magnetization was 400 G (at 4KO@). The electrode portion is connected to a power source 34 via a high resistance (35). This is to protect the current device and photoreceptor from excessive current that may occur due to damage to the high-resistance photoreceptor.

The photoreceptor 32 is charged by a band Wllv pole and subjected to image exposure at 36 to form an electrostatic latent image.

The electrostatic latent image is developed with toner in a developing device 37 to become a toner image, which is transferred onto a transfer member 39 such as paper to obtain a recorded matter. 40 is a transfer electrode for electrostatically transferring the toner image onto the transfer plate, and 41 is a separation electrode for separating the transfer material from the surface of the photoreceptor. The surface of the photoreceptor after image transfer is cleaned by a cleaning device 42 and used repeatedly. The transfer material 39 is fed in synchronization with the photosensitive drum 31, but its feeding device is omitted from this figure.

When the apparatus shown in this figure was operated at a charging applied voltage of 700 mm and a photoreceptor linear velocity of 160 mm/sec, extremely good recorded matter could be obtained.
Furthermore, even in high-speed operation where the photoreceptor linear velocity was increased to 30,071 (z/sec), stable and good charging could be achieved. Also, the applied voltage of 700 mm was significantly lower than the applied voltage of 5 to 6 KV required for the electrode. This was extremely low, proving the effectiveness of the present invention.

Furthermore, as a matter of course, the generation of harmful substances such as ozone could not be alleviated.

[Brief explanation of the drawing]

Figure 1: Structure diagram of charging and neutralizing electrodes Figure 2: Conceptual diagram of charging and neutralizing device Figure 3: Schematic representation of electrostatic recording device using a band device
Yoshimi Kuwahara 4

Claims (3)

[Claims] (1) In an electrostatic recording device that forms an electrostatic latent image on an insulator, a magnetic field generating means provided close to the surface of the insulator, and a magnetic field held within the magnetic field formed by the magnetic field generating means. 1. A charging and discharging device for electrostatic recording, comprising a ferromagnetic metal fluid, the ferromagnetic metal fluid being brought into contact with the surface of the insulator. (2) Special i' characterized in that the insulator has photoconductivity
(r) A charging and neutralizing device for electrostatic recording according to claim 1. (3) The charging and discharging device for electrostatic recording according to claim 1, wherein the magnetic field generating means has a variable magnetic field direction.