JPS63158576A - Electric discharge device - Google Patents

Abstract

PURPOSE:To execute satisfactory electric discharge, even if a member to be electrified is a photosensitive body, by providing an air hole connected to a space between a dielectric and the surface of the member to be electrified on the dielectric. CONSTITUTION:An air hole 20 penetrating in the vicinity of electrodes 11, 12 is pierced on a dielectric 10. This air hole 20 communicates with an air chamber 23 formed by holding the dielectric 10 in a stepped part 3b by a holding material 3. A tube attaching port 3c is provided, on a part of the holding material 3, and a suction tube 22 is attached thereto. That is, as for the suction tube 22, its one port is fitted to a suction pump, and the other is fitted into the holding member 3 through the tube attaching port 3c, and this tube has a function for leading the air sucked from the air hole 20, to the suction pump. In such a way, NNOx, and ozone does not remain on the surface of a photosensitive body 2, and there is no possibility that characteristics of the photosensitive body are varied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is used in the field of discharge technology, and particularly relates to a discharge device for charging and neutralizing a photoreceptor of an electrophotographic copying machine.

(Prior Art) This type of discharge device applies an alternating current voltage between electrodes provided so as to sandwich a dielectric material, and generates positive and negative ions by causing a discharge near one of the electrodes. A charging device that extracts ions of a predetermined polarity among these ions toward the charged member using an electric field formed by a bias voltage applied between the one electrode and the charged member, and attaches them to the charged member; It is known, for example, as shown in US Pat. No. 4,155,093.

In this method, the electrodes where the discharge takes place are exposed;
Since the discharge occurs strongly near this exposed electrode, 2
The electrodes are easily corroded due to plasma elution and fermentation effects caused by discharge. When such corrosion occurs, the discharge becomes uneven, resulting in uneven charging action, which poses a problem in practical durability.

Therefore, with the aim of improving the above-mentioned durability, the applicant has
It has a dielectric, at least two electrodes buried in the dielectric, and an exposed electrode, and the buried electrode has a dielectric at a predetermined discharge starting voltage when an alternating current voltage is applied between them. The exposed electrode is placed at a position where a discharge occurs near a part of the surface of the body, while the exposed electrode is located at or near a part of the surface and has a discharge starting voltage between it and any buried electrode. In Japanese Patent Application No. 61-1895/I, a discharge device was devised in which the discharge device was installed at a position higher than the predetermined discharge starting voltage.

In this device, a serious problem is the accuracy of the distance between the discharge electrode and the surface of the charged member.

That is, in this case, if the above-mentioned distance becomes larger than a predetermined value, the extracted ions will not reach the surface of the member to be charged, and the charging effect will be significantly reduced.

For this reason, it is necessary to increase the voltage applied between the electrodes to increase the amount of ions extracted to compensate for the decrease in charging effect due to the increase in the distance between the electrode and the surface of the charged member, which increases power consumption and reduces electrode durability. It will be a burden again.

On the other hand, when the above-mentioned distance becomes smaller than a predetermined value, the charging effect increases significantly, and charging can be performed with low power consumption. However, slight variations in distance tend to cause uneven charging, making it unsuitable for devices that require uniform image quality, such as copying machines.

Therefore, as a further countermeasure against this problem, the present applicant has devised a method of bringing the holder that holds the dielectric of the discharge device into contact with the surface of the charged member, and using this method, the distance between the surface of the charged member and the above-mentioned electrodes is increased. This made it possible to make it extremely narrow and stable.

(Problems to be Solved) As described above, according to the above-mentioned chamber, the distance to the surface of the charged member can be easily narrowed, and can be set accurately and stably.
Is it possible to make it suitable for a copying machine? However, if the distance between the charged member and the above-mentioned electrode is several layers, the air flow intervening between the charged member and the above-mentioned electrode may be too large. It was found that NOx and ozone (0:I), which are generated together with ion generation, remained at the electrode part mouth. This means that if the member to be charged is a photoconductor used in a copying machine, especially a leaf C photoconductor, N
Due to the influence of Ox and ozone (0), the copied image may be blurred,
This causes a flow, and in the worst case, it becomes a serious problem where the image formation is 1TTte.

Also, ozone (01) is a gas with strong oxidizing power, so
This also causes deterioration of the discharge device and peripheral equipment.

(Means for Solving the Problems) The present invention solves the above-mentioned particular problems and provides a discharge device that can perform good discharge even when there is a charged member or a photoreceptor. At least two electrodes are embedded in the dielectric body to be immersed; an exposed electrode for applying a bias voltage is provided in the dielectric body to be buried, and an air hole is provided that connects to the space between the dielectric body and the surface of the member to be charged. It is characterized by:

(Example) Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a sectional view of one embodiment of the discharge device of the present invention.

The discharge device of this embodiment has at least two buried electrodes 11.12 buried in the dielectric 10 and an exposed electrode 13 provided on the surface of the dielectric 10. The body IO is held by the holding member 3.

The two buried Ts above! J4j l l, 12 is an electrode for applying an alternating current voltage to generate a discharge, and a bare electrode 13 is applied with a bias voltage for extracting ions generated by the discharge to the charged member 2. It is an electrode. The buried electrodes 11, 12 and exposed electrodes I3 extend in the direction perpendicular to the plane of the paper in FIG. 1, which is the longitudinal direction of the dielectric IO.

The holding material 3 is made of a synthetic resin molded product and holds the dielectric material 10 with a snap fit that utilizes the elasticity of the resin. At the same time, a stepped portion 3b is formed in the middle, and the dielectric 1O is held by the claw-shaped portions 3a of the holding member 3. Further, the claw-shaped portion 3a of the holding member 3 is in contact with the photoreceptor 2, and by contacting the surface of the photoreceptor 2 in this way, the dielectric 10 is held at a constant distance from the surface of the photoreceptor 2. .

Furthermore, an air hole 20 penetrating through the dielectric IO is provided in the vicinity of the electrodes 11 and 12. Preferably, a plurality of air holes 20 are formed along the longitudinal direction of the electrodes 11 and 12 in parallel and close to each other.

The air hole 20 communicates with an air chamber 23 formed by holding the dielectric 10 on the holding member 3 or the stepped portion 3b. In this way, in this embodiment, the holding material 3 that holds the dielectric 10 serves to form the air chamber 23, and forms a guide path for air passing through the air holes 20 formed in the dielectric 10. are doing.

A tube attachment opening 3C is provided in a part of the holding member 3, and the suction tube 22 is attached to this in this embodiment. That is, the suction tube 22 is fitted into the holding material 3 with a suction pump (not shown) connected to one mouth and a tube attachment port 3c connected to the other end, and the air sucked through the air hole 20 is sucked. It serves as a guide to the pump.

Hereinafter, the dielectric lO1 buried electrode 11, 12 and exposed electrode 13 will be described in detail, including their materials.

The dielectric 10 is an inorganic dielectric material with high discharge resistance, such as glass, ceramic, etc. 5i02. MgO, 81□03 oxide, or silicon nitride (Si: +N4)
It is made of a nitride such as aluminum nitride (AIN), and in this embodiment, it is a long member with a rectangular cross section.

The electrodes 11.12 embedded in the dielectric IO are arranged in the figure parallel to the bottom surface of the dielectric IO (the surface facing the photoreceptor 2) and equidistant therefrom.

This is not essential or preferred for manufacturing reasons. Buried electrode 11
．． 12 is set at a position where, when an alternating current voltage is applied between them, a discharge occurs near a part of the surface of the dielectric 10 at a predetermined discharge starting voltage. As materials for these electrodes, AI, Cr, Au, Ni, etc. can be used. What should be noted here is that in the present invention, these electrodes are buried and not exposed, and are therefore less likely to corrode, so that high durability can be maintained even when the above materials are used.

The distance between the buried electrodes is preferably 17 tm or more, particularly 3 to 200 gm, in consideration of dielectric strength.

The electric body 10 may be integrated in this embodiment, or it may be a two-layer dielectric body joined to the upper surface or the lower surface of the dielectric body 10 and/or the buried electrode 1. In this case, the materials of each layer may be the same or different. In particular, when the dielectric layer is made of two layers, the dielectric layer on the back side where discharge occurs is made of an inorganic material with high discharge resistance to guarantee the life of the dielectric material, and the dielectric material on the other side is made of an organic material. Dielectrics may also be used. In either case of an integrated structure or a two-layer structure, the thickness of the dielectric material below the buried electrode should be at least 100 m,
The exposed electrode 13, which preferably has a thickness of 500 gm or less, particularly 3 layers of 1 or more and 200 JL or less, is fixed to the bottom surface of the discharge device 1 in which discharge by the alternating current voltage is generated in this embodiment. The material of this electrode 13 is a conductive metal with high corrosion resistance and RGM property, such as Ti, W, Cr, Te, Mo,
High-melting point metals such as Fe, Go, Ni, Au, and PL, alloys containing these metals, or oxides are used. Its thickness is 0.1 to 100 elongation-1 preferably 0.2
~20 pots, width at least 1L, preferably 10-5
00 gm. The exposed electrode 13 is located near the end of the discharge generation region 15, and is located near any buried electrode (11).
and 12) is a position where the AC applied voltage that causes discharge initiation is higher than the predetermined discharge initiation voltage. Here, the vicinity of the discharge area refers to the vicinity including the outside and the inside thereof, and whether it is outside is preferable, or even if it is inside, it is satisfactory for one device as long as it is close to the end of the discharge area.

In this embodiment as described above, discharge is performed as follows. Note that the discharge device of this example is as follows.

Whether it can be used to neutralize or charge the photoconductor 2 consisting of the dielectric layer or photoconductor layer 17 and the conductive substrate 18, the principles of neutralization and charging are similar, so only the case of charging will be described.

When an AC voltage higher than a predetermined discharge starting voltage is applied between the buried electrode 11 and the buried electrode 12 by the AC power supply 14, this causes the bottom surface of the dielectric lO of the illustrated discharge device (the electrode to which the AC voltage is applied Discharge is performed in a single region indicated by reference numeral 15, centered on a portion facing the vicinity of the electrodes (a plane substantially parallel to the line connecting 11 and 12), and a positive
Negative ions are generated alternately. However, bare electrode I
Since a bias voltage 19 is applied to the photoreceptor 3, ions of a desired polarity among the ions are extracted toward the photoreceptor 2, and the photoreceptor 2 is charged. Note that the polarity of the extracted ions is determined by the polarity of the applied bias voltage.

When a discharge occurs in such a situation, NOx and ozone (03) are generated around the electrode due to the discharge, but in this case, even if the distance between the photoreceptor 2 and the above-mentioned electrode is small, the suction air will continue to flow. It is also removed to the outside and does not stay around the electrode section.

That is, a suction tube 22 is fixedly attached to the holding member 3, and the suction pump suctions air through this suction tube 22. When air is suctioned by the suction pump, the air inside the air chamber 23 is suctioned by the suction pump, and the air pressure inside the air chamber 23 decreases, creating a pressure difference between the air chamber 23 and the outside. arise.

Here, since the dielectric body 10 is provided with a plurality of air holes 20, the air containing a large amount of NOx and ozone (0:l) between the dielectric body 10 and the photoreceptor 2 flows into the air chamber 23. In order to make the pressure difference uniform, the air chamber 23 passes through the air hole 20.
It flows into the interior and is sucked into the suction pump.

With the above method, during operation of the discharge device, NOx and ozone (03) generated around the electrode due to discharge are sucked through the plurality of air holes, so that NOx and ozone (03) are deposited on the surface of the photoreceptor 2.
Also, there is no possibility that ozone (03) will remain and the photoreceptor characteristics will change.

As described above, in this embodiment, a plurality of holes 20 are formed in the dielectric IO of the discharge device, and air is absorbed through the through holes 20 to form the surface of the photoreceptor and the bare electrode of the discharge device. NOx and ozone (03
) to remove air containing a large amount of

Therefore, even if the space between the dielectric material lO and the surface of the photoreceptor 2 is made extremely narrow, the problem of poor air flow due to the air holes 20 can be improved, and the distance between the surface of the photoreceptor and the bare electrode surface of the dielectric material can be improved. When suctioning the air interposed between
NOx and ozone (03) generated during charging can be reliably removed from the space between the photoreceptor surface and the bare electrode surface of the dielectric. If NOx and ozone (03) are removed, even if there is a charged member or photoreceptor 2, the NOx and ozone (03) that cause blurring and flow of copied images will remain around the electrode area. Therefore, it is possible to perform a good discharge action from a short distance with low power consumption without changing the characteristics of the photoreceptor. Furthermore, ozone (03) does not cause deterioration of equipment and peripheral equipment due to radiation.

In the above embodiment, the dielectric IO is provided with air holes 20, and the air is sucked through the holes for removal. Removal can also be performed by That is, in the above embodiment, the air containing a large amount of NOx and ozone (03) was sucked in from the air hole 20 by the suction pump. It becomes possible to blow fresher air onto the surface of the photoreceptor.

At this time, the air containing a large amount of NOx and ozone (03) generated around the electrode is suppressed by the pressure of the air blown out from the air hole 20, and the surface of the photoreceptor is constantly exposed to fresh air flowing in from the outside. Because of this, NOx, ozone (03
) will not cause problems such as toner image flow or blurring on the photoreceptor.

Further, regarding the air holes 20, in this embodiment, the air holes 20 are provided at the side positions of the electrodes as shown in FIG.
Air holes 20 may be provided between each row of the electrodes as shown. Specifically, a pair of discharge electrodes 11, 12 and a bias electrode 1 for ion extraction as shown in FIG.
It is also possible to provide an air hole 20 between the left and right sets of discharge electrodes in a discharge device having two sets of discharge electrodes on the left and right sides of the dielectric. By doing this, it is possible to improve the air flow and prevent NOx and ozone (03) from remaining.

Note that, not only when the pair of electrodes 11 and 12 are disposed in the dielectric IO and are arranged side by side in the horizontal direction as shown in FIG. 2, but also when they are buried vertically in parallel, the second It goes without saying that air holes can be provided between the left and right sets of discharge electrodes as shown in the figure.

(Effects of the Invention) As described above, according to the device of the present invention, air holes are provided in the dielectric material having the electrodes to improve the flow of air.
This prevents ozone (03) and ozone (03) from remaining around the dielectric electrode, so NOx and ozone (03) generated during discharge are removed from the space between the surface of the charged member and the bare electrode surface of the dielectric. Since it can be removed, the charged member or OP
Even in the case of a C photoconductor, it is possible to achieve the effect of enabling discharge at a shorter distance with lower power consumption without changing the photoconductor characteristics.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention. FIG. 2 is an explanatory diagram illustrating the formation of air holes and the like. 10... Dielectric 11.12... Buried electrode 13... Bare electrode 20... Air hole

Claims (4)

[Claims] (1) A dielectric body in which at least two electrodes for applying an AC voltage are embedded is provided with an exposed electrode for applying a bias voltage, and a through air hole is connected to the space between the dielectric body and the surface of the charged member. A discharge device characterized by: being drilled therein. (2) The discharge device according to claim (1), wherein the air holes are provided at a plurality of positions. (3) The discharge device according to claim (1), wherein the air hole is connected to suction or blowing means. (4) The discharge device according to claim (3), wherein the air guide path for suction or air blowing is formed of a holding material that holds a dielectric.