JPS6029764A - Destaticizing device - Google Patents

Abstract

PURPOSE:To enable effective destaticization of the surface electrifying potential of paper by providing the 1st electrode consisting of fibrous conductors and the plate-shaped 2nd electrode to face each other with paper in-between, impressing a DC voltage to the 2nd electrode and increasing the electric field intensity between the paper and the 1st electrode. CONSTITUTION:The 2nd electrode 2 is provided in the position where said electrode faces the 1st electrode 1 with paper PA in-between. The bias potential V0 in the same direction as the surface electrifying potential V of the paper PA is applied from a DC power source 3 to the 2nd electrode 2. The destaticizing effect for the paper PA moving in the direction of an arrow F1 is increased by as much as the bias potential V0 applied via the 2nd electrode 2. The destaticization of the paper having any surface electrifying potential is therefore made possible according to the level of the bias potential and it is not always necessary to bring the fibrous conductors constituting the 1st electrode 1 into contact with the surface of the paper PA and therefore the wear, pull-off and breakage of the 1st electrode 1 are prevented and the long-term use is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a static eliminator that is disposed in a paper transport path of, for example, an electrophotographic photographic machine, a printer, etc., and completely eliminates static electricity from the paper that passes through the transport path. - [Prior Art] Generally, in the above-mentioned electrophotographic copying machines and the like, paper is often unnecessarily charged due to friction caused by rubber rollers, heating during fixing, and the like. Such unnecessary charging of paper can cause errors in the normal operation of the machine, and can seriously impair the operability of the operator due to the need for paper. Development has been progressing ever since.

One of the devices currently in practical use is a so-called self-discharge promoting type static eliminator that discharges electrical charges on paper through electrodes made of a large number of thin fibrous conductors. Such a static eliminator has a simple structure and is advantageous in terms of cost, so it is currently widely used. Used in machines and printers.

However, not all problems have been solved with the advent of the above-mentioned static eliminator.

In other words, in the case of the same charge removal device, when the charge potential on the surface of the paper is high, it exhibits a good charge removal effect, but when the charge potential is low, it exhibits almost no effect, so in practical use, The fibrous conductor serving as the electrode had to be brought into contact with the surface of the paper, and the electrical charge had to be discharged by this contact leakage. As a result, the fibrous conductor is subject to severe wear, and the conductor is also prone to breakage and breakage, making it unavoidable to use the device for a long period of time. Furthermore, the fibrous conductors that have fallen out or broken have become attached to the electrical circuits in the machine, causing new problems such as interfering with the normal operation of the machine.

[Purpose of the Invention] The purpose of the present invention is to provide a static eliminator that can effectively eliminate static electricity from any sheet of paper that has a harmful potential on its surface, and that can be used for a long period of time while maintaining safety. do.

[Structure of the Invention] The present invention focuses on the fact that the anti-sleep effect of the static eliminator is proportional to the electric field strength between the electrodes and the paper, and the static eliminator is placed in a position facing the electrodes while holding the paper. Furthermore, another second electrode is provided, and a DC voltage is applied to this second electrode to increase the total electric field strength. As a result, the electrical charge on the surface of the paper can be easily transferred to the electrode made of the many thin fibrous conductors mentioned above, that is, the first electrode, and even if this potential is low, it can be easily transferred through the first electrode. The battery can be effectively discharged. In addition,
Although the shape of the second electrode is arbitrary, it is preferable that the second electrode has the shape of a main electrode plate in this apparatus in which the entire sheet of paper is to be neutralized.

〔Effect of the invention〕

As described above, according to the static eliminator according to the present invention, the static elimination efficiency is significantly improved, and for this reason, it is possible to realize effective static elimination even when the first electrode does not come into contact with the entire surface of the paper. Become.

Therefore, the above-mentioned wear and tear on the first electrode,
This also prevents breakage and allows the static eliminator to be fully used safely and over a long period of time. Furthermore, due to the above-mentioned improvement in static elimination efficiency, a material with a high resistance value can be used as the fibrous conductor for the first electrode, and even if it falls out or breaks, it may not adhere to the electric circuit. Even if something happens, the risk of it becoming serious is low.

〔Example〕

First, the present invention will be explained in detail with reference to FIGS. 1 and 2.

FIG. 1 shows a static eliminator that discharges the electrical charges on a paper PA moving in the direction of arrow F1 in the figure using only striped electrodes 1 made of a large number of thin fibrous conductors, unlike conventional devices. The structure and its function are schematically shown. In the figure, V indicates the surface potential of the paper PA, and y-E indicates the electric field strength between the paper PA and the first electrode 1. , and d indicate the distances between these sheets of paper PA and the first electrode 1, respectively.

Therefore, in the case of this device, the electric field strength E is E=V/
Since the static elimination effect of the device is proportional to the electric field strength 7, the static elimination effect of the device will be expressed as A (1=kE=kV/d (k is In other words, the higher the charging potential V or the shorter the distance d, the more the electric field strength E increases, and the more effective the division likelihood effect A improves.

On the other hand, in FIG. 2, a second electrode 2 is further provided at a position facing the above-mentioned first electrode 1 while sandwiching the paper PA, and a direct current source 3 is connected to the second electrode 2 to connect the paper PA to the paper PA.
Bias potential V in the same direction as the surface charge potential V. In addition, this figure schematically shows the structure and operation of the static eliminator according to the present invention, which discharges the charged @odor from the paper PA moving in the direction of the arrow F1 in the figure, as described above.

Therefore, in the case of this device, the above electric field strength E is B=CV 10V. )/d The static elimination effect of the device is expressed as A.

Ao=kE=k(V+V.)/d (k is a proportionality constant) The same static elimination effect increases by the amount of potential v0.This means that this bias potential ■.

Depending on the level of the paper PA, it is of course possible to eliminate static electricity from any sheet of paper with a surface charge potential. This means that even if the shaped conductor is made of a material with a high resistance value, it is possible to effectively eliminate static electricity.

FIG. 3 shows, as an embodiment of the static eliminator according to the present invention, a configuration in which the static eliminator is applied to a paper discharge section of an electrophotographic copying machine.

In FIG. 3, the copying machine 100 includes a photosensitive drum 101
, a charging corotron 102 that charges the photoreceptor drum 101, a rung 103 that scans and illuminates the placed original OR, and optical systems 104a, 104b, and 104es that expose the entire surface of the photoreceptor drum 101 to the reflected light.
A developing device 105 that develops the electrostatic latent image formed on the surface of the photoreceptor drum 1010 by the exposure, a transfer corotron 106 that transfers the developed image onto the paper PA conveyed by various conveyance rollers, and a photosensitive device after the transfer. A static eliminating corotron 107 that eliminates static electricity from the surface of the body drum 101
, a cleaning device 108 for cleaning the surface of the drum 1010 after the static electricity removal, and a cleaning device 108 for cleaning the surface of the drum 1010 after the static electricity removal,
A fixing device 10 fixes this transferred image by heating A.
9, and a controller 1 that centrally controls each of the above-mentioned devices so that the operations related to copying are executed smoothly.
This is a known electrophotographic copying machine equipped with a first electrode 10 made of a large number of thin filament-like conductors, a second electrode α20 made of a grate-like conductor, and the second electrode α20. As shown in FIG. 3, the static eliminator of the present invention has a DC power source 30 that applies a DC voltage to a DC voltage source 20 and performs static neutralization based on the above-described principle.As shown in FIG. The first and second electrodes 10 and 20 are connected to the paper discharge section of the copying machine 100 so as to discharge
They are arranged so as to sandwich the transport path PAL of the paper PA, respectively. However, in the static eliminator of this embodiment, the timing of applying DC voltage to the second electrode 20 by the DC power supply 30 is also controlled by the controller 110 described above so as to correspond to the series of copying operations described above. The moon paper PA is connected to the first and second electrodes 1
Only when passing between gates 0 and 20, static elimination based on the above-mentioned principle is performed.

Alternatively, it is of course possible to adopt a configuration in which, for example, the voltage is applied to the second voltage 20 only while the copying machine 100 is powered on. Furthermore, in this embodiment, the second electrode 20 to which a high 7a voltage is applied is covered with an insulator 21 made of plastic or the like for safety reasons.

By providing the static eliminator according to the present invention in the manner described above, it is possible to effectively and reliably eliminate static electricity from the paper PA discharged from the copying machine 10'0, and as a result, the operator can This can bring great convenience in organizing the paper PA.

If the above-mentioned copying machine is a double-sided copying machine, the static eliminator of this embodiment can be further installed in front of the paper reversing mechanism to prevent malfunctions of the copying machine due to unnecessary charging of the paper. This also makes it possible to effectively avoid paper jams and the like.

Further, the application of the static eliminator according to the present invention is not limited to the above-mentioned copying machine, but is also applicable to a wide range of applications, such as use as an output device or internal processing device of a printer that has a structure in which paper is easily charged, and even as a portable device. It can be widely applied as a stand-alone device for other purposes.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing the principle of the static eliminator according to the present invention, and FIG. 3 shows an embodiment of the static eliminator according to the present invention at the paper ejection section of an all-electrophotographic copying machine. Composition when applied to? FIG. 1.10...Fibrous conductor that is the first electrode, 2°20
...Plate-shaped conductor, which is the second electrode, 3°30...
・DC'#L source, 21... Insulator, 1oo... Copying machine, 101... Photosensitive drum, 1o2... Charging corotron, 103... Lamp, 104... Optical system,
105... Developing device, 106... Corotron for transfer, 107... Corotron for static elimination, 108... Cleaning device, 109... Fixing device, 110... Controller, PA... Paper, PAL ...Paper transport path, O
R...Manuscript. Figure 1 Figure 2

Claims (2)

[Claims] (1) In a static eliminator that discharges electrical charges on paper via a first electrode made of a large number of thin fibrous conductors,
a second electrode sandwiching the paper and facing the first electrode;
an electrode is provided, and the second electrode is provided with a directivity ηt′t that increases the electric field strength between the paper and the first electrode.
4L pressure was applied, and the static electricity was removed as a sign of e%. − (2) The static eliminator according to claim (1), wherein the second electrode is a plate-shaped conductor.