JPS6117164A - Discharging device - Google Patents

Abstract

PURPOSE:To form a discharging device capable of uniform destaticization and electrification by equalizing the length of an induction electrode to the width of destaticization/electrification. CONSTITUTION:The length l of an induction electrode 3 is equal to an electrification width L of a member 5 to be electrified, and the length of a discharging electrode 4 is made slightly longer than the electrification width L. The length of the induction electrode and the electrification width of the member to be electrified are equalized to each other in this manner to electrify uniformly the member 5, which is moved in the direction of an arrow B relatively to a discharging member 1, with the electrification width L because a discharging area in the lengthwise direction of the discharging member is determined by the length in the lengthwise direction of the induction electrode. That is, discharging occurs only in a part of the discharging electrode corresponding to the length of the induction electrode, and a bias voltage does not contribute to electrification of the member to be electrified in parts other than the discharging part though the bias voltage is applied between the discharging electrode and a conductor base body.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a discharge device for charging and eliminating static electricity in electrostatic recording, electrophotographic devices, and the like.

(Prior Art) Conventionally, in electrostatic recording and electrophotographic devices, in order to remove static electricity, a corona discharge device is used that generates corona discharge by applying a high voltage to a wire with a wire diameter of about 0.1 thread. is widely used. However, in such a corona discharge device, the wire is thin and easily damaged, and even a small amount of dirt on the wire tends to cause harmful discharge unevenness, and this discharge unevenness causes uneven removal and charging of the target and charged member. It has the disadvantage that it becomes resistant to electricity when it is in a charged state.

In addition, the corona discharge device uses a relatively long wire.

The wire is stretched inside the conductive shielding member by applying tension to both ends, but depending on the tension, the weight of the wire, etc., the charged member to be charged with Fi is removed at the ends and center of the corona discharge device. The distance changes continuously.

For this reason, there is a drawback that the state of charge removal and charging becomes uneven between the ends and the center of the corona discharge device.

Furthermore, it is necessary to maintain a certain distance between the wire and the conductive shielding member surrounding the wire, which limits the miniaturization of the corona discharge device.

On the other hand, as another discharge device, an AC voltage is applied between electrodes that sandwich a dielectric material, thereby generating positive and negative ions at the junction between the end face of one electrode (discharge electrode) and the dielectric material. There is a method that extracts ions of a desired polarity using an external electric field (Japanese Patent Application Laid-open No. 54-53537, Japanese Patent Application No. 187399-1980 filed by the applicant of the present invention). In such devices, the dielectric thickness is reduced (e.g., 5
00 μm or less, preferably about 20-200 μm), the discharge device can be made smaller compared to conventional corona discharge devices. According to this discharge device, since the discharge electrode is fixed to the dielectric material, burning of the discharge electrode can be prevented, and the distance between the discharge electrode and the covered/charged member can be kept constant. . This will be more effective if the discharge device is simply reinforced.

Furthermore, when an alternating current voltage is applied between the electrodes, discharge occurs actively, and the discharge electrodes have the advantage of being less likely to become dirty and less likely to experience uneven charging or uneven static removal.

However, when such a discharge device is used to remove and charge a charged member, the amount of discharge increases at the ends of the discharge electrodes depending on the position of the electrodes that sandwich the dielectric, and uneven removal and charging may occur. It turns out that this happens.

(Object of the invention) The present invention has been made in view of the above problems, and is a method for uniform removal and
An object of the present invention is to provide a discharge device that can be charged.

(Summary of the Invention) The present invention is a discharge device in which ions are generated in the vicinity of the discharge electrode by applying alternate voltages to an induction electrode and a discharge electrode that sandwich a dielectric. It is characterized in that the length of the discharge electrode is made equal to the removal/charging width of the charging member, and the length of the discharge electrode is slightly longer than the removal/charging width.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) and 1(b) are a sectional view and a plan view illustrating the basic configuration of a discharge device according to the present invention.

The discharge member l is a dielectric material 2. Induction electrode 3. It has a discharge electrode 4, and an induction electrode 3 and a discharge electrode 4 are respectively arranged in the longitudinal direction of the dielectric 2 with the dielectric interposed therebetween.

The discharge member 1 has a uniform thickness. ``Such a discharge member 1 is placed with respect to the charged member 5 with the discharge electrode 4 facing the charged member 5. Dielectric materials include inorganic materials such as ceramic, mica, and glass, polyimide,
Organic polymer materials such as tetrafluoroethylene, polyester, acrylic, vinyl chloride, and polyethylene are used, and each electrode is made of a conductive material.

An alternate voltage application means 6 is provided between the induction electrode 3 and the discharge electrode 4.
Alternating voltages are applied by. The waveform of this alternating voltage may be any waveform such as a sine wave or a pulsed rectangular wave.

On the other hand, a bias voltage is applied between the discharge electrode 4 and the conductive substrate 5a of the charged member 5 by the bias voltage applying means 7Fc. Note that this bias voltage is applied to the conductor base 5a.
and the induction electrode 3.

The charging method is to apply alternate voltages between the induction electrode 3 and the discharge electrode 4 to generate a discharge from around the discharge electrode 4, generate enough positive and negative ions, and connect the discharge electrode 4 and the conductor. The positive or negative ions are selectively extracted by an electric field caused by a bias voltage applied between the substrates 5a, and the surface of the insulator or photoconductor 5b of the member to be charged 5 is charged to a specific polarity and a desired value. It is something that makes you

However, with the electrode arrangement as shown in FIGS. 1(a) and 1(b), 1 occurs at the ends A and A' of the discharge electrode 4 because the creepage distance with the induction electrode 3 increases. The amount of positive and negative ions is larger than in other parts of the discharge electrode. Therefore, when the charged member 5 is charged, the end portion of the discharge electrode 4 is charged in a larger amount than other portions, resulting in uneven charging, as shown in FIG. 1(c). Put it away.

Accordingly, in one aspect of the present invention, the above problem is solved by making the length of the induction electrode in the longitudinal direction coincide with the charging width of the member to be charged.

2(a) and 2(b) are diagrams explaining the present invention in detail, FIG. 2(a) is a cross-sectional view of the discharge device, and FIG. 2(b) is a plan view of the discharge device as seen from the induction electrode side. It is a diagram. According to this embodiment, the length l of the induction electrode 3 is set equal to the charging width of the charged member 5, and the length of the discharge electrode 4 is set to be slightly longer than the charging width. In this way, by matching the length of the induction electrode and the charging width of the charged member, the charged member 5 that moves in the direction of arrow B relative to the discharge member 1 is charged uniformly with respect to the charging width LK. be able to. this is,
This is due to the fact that the discharge area in the longitudinal direction of the discharge member is determined by the length of the induction electrode in the longitudinal direction. In other words, discharge occurs only in the discharge electrode portion corresponding to the length of the induction electrode, and even if a bias voltage is applied between the discharge electrode and the conductive substrate, areas other than the discharge portion do not contribute to the charging of the charged member. It's for a reason. Therefore, Fig. 1 (c
), the amount of charge increases at the end of the discharge electrode, causing uneven charging, and the member to be charged can be charged uniformly.

In the present invention, the charging width of the charged member is defined as the charging width in the direction perpendicular to the moving direction B when the charged member moves other than the discharge portion as shown in FIG. 2(b). It refers to the width.

In this embodiment, the case where a member to be charged is charged has been described as an example, but it goes without saying that the present invention is also applicable to the case of static elimination.

(Effect of the invention).

As described above, according to the present invention, by making the length of the % induction electrode match the removal/charging width, it is possible to perform uneven removal/charging on the material to be removed/charged.・It is now possible to remove and charge only the necessary areas of the charged member.

[Brief explanation of drawings]

FIG. 1(a) is a sectional view illustrating the basic configuration of the discharge device according to the present invention, FIG. 1(b) is a plan view of the discharge device viewed from the discharge electrode side, and FIG. 1(c) is a discharge device. A graph showing the amount of charge on the charged member in the longitudinal direction of the electrode, FIG.
FIG. 2(b) is a plan view of the discharge device viewed from the visiting electrode side. 1: Discharge member 2: Dielectric material

Claims (1)

[Claims] a dielectric, an induction electrode and a discharge electrode sandwiching the dielectric;
It has an alternating voltage application means for applying an alternating voltage between the induction electrode and the discharge electrode to generate ions in the vicinity of the discharge electrode, and the length of the induction electrode is determined by the length of the induction electrode, the removal of the charging member, and the charging width. , and the length of the discharge electrode is slightly longer than the charging/removal width.