JPS63129362A - Discharging device - Google Patents

Abstract

PURPOSE:To efficiently, dehumidify the periphery of the electrode of a device, to reduce the power consumption, and to perform uniform and stable discharging by providing the discharging device with a humidity detecting means and controlling a heat generating body according to the output of this humidity detecting means. CONSTITUTION:When an AC voltage above is specific discharging start voltage is applied between embedded electrodes 11 and 12 from an AC power source 14, discharging is carried out in a single area 15 around a part facing the periphery of the part between the electrodes on the bottom surface of the discharging device 1 to generate positive and negative ions alternately. A bare electrode 13, on the other hand, is applied with a bias voltage by a bias power source 19, so ions having a desired polarity are extracted toward a member 2 to be charged electrostatically, so the member 2 is charged electrostatically. A microcomputer 22 supplies electric power to the heater 21 when the value of a current inputted from a humidity sensor 23 varies exceeding a recording current value recorded in the microcomputer to raise the temperature of a dielectric 10, there removing moisture around the discharging device.

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 disposed to sandwich a dielectric material to generate a discharge near one electrode to generate positive and negative ions. A charging device extracts ions of a predetermined polarity among the ions toward the charged member by an electric field formed by a bias voltage applied between the one electrode and the charged member, and makes them adhere to the charged member, For example, it is known as shown in US Pat. No. 1,155,09:1.

In this method, the electrodes where the discharge takes place are exposed;
Since the discharge occurs strongly near this exposed electrode,
The electrodes are easily corroded by plasma etching, oxidation, etc. caused by discharge. When such corrosion occurs, the discharge becomes uneven, resulting in uneven charge removal and charging effects, which poses a problem in practical durability.

Therefore, with the aim of improving the above-mentioned durability, the applicant has
It has a dielectric material, at least two electrodes buried in the dielectric material, and an exposed electrode, and the buried electrode is capable of discharging the dielectric material at a predetermined discharge starting voltage when an alternating current voltage is applied between them. It is placed in a position where an electrical discharge is generated near a part of the body's surface.

On the other hand, the exposed electrode is located at or near a part of the surface, and has a structure in which the discharge starting voltage between it and any buried electrode is higher than the predetermined discharge starting voltage. This discharge device was devised in Japanese Patent Application No. 18954/1983.

With the above-mentioned proposal, the durability against electrode corrosion due to electric discharge has been significantly improved.

(Problems to be Solved) As described above, with the L-chamber arrangement, there is a problem of whether durability can be improved or that the surface absorbs moisture. In other words, if the discharge device is not in use, moisture in the air will adhere to the surface of the dielectric and electrode, so even if the power is turned on, a discharge will not occur unless the humidity on the surface of the electrode and dielectric decreases. have. For this reason, it is very difficult to discharge when the humidity of the atmosphere is high or when there is condensation on the device in cold weather.

In order to solve the above problem, there is a method of gluing or pressure-bonding a heating element near the discharge device or on the surface of the discharge device where electrodes are not formed, raising the temperature of the entire discharge device, and eliminating moisture from the dielectric and electrodes. Conceivable.

However, when power is constantly supplied to the heating element, the power consumption increases despite the fact that the discharge device has low power consumption and is capable of discharging with a low current.

Further, it cannot be expected to perform uniform and stable discharge quickly and efficiently under a wide range of environmental conditions.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned particular problems, and includes a method for applying a bias voltage to a dielectric body in which at least two electrodes for applying an AC voltage are embedded. and a heating element for heating the dielectric, a humidity detection means for detecting humidity, and a control means for controlling the heating element based on the output of the humidity detection means. This is a characteristic feature.

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

FIG. 1 is a sectional view of a discharge device according to an embodiment of the present invention.

The discharge device 1 of this embodiment includes at least two buried electrodes II, 12 buried in a dielectric 10, and the dielectric 1
It has a bare electrode 13 provided on the surface of 0. J
The two buried electrodes 11 and 12 are electrodes for applying an alternating current voltage to generate a discharge, and the exposed electrode 13 is for extracting ions generated by the discharge toward the charged member 2. It is the electrode to which the bias voltage is applied.

A humidity sensor 23 as a humidity detection means is provided on the dielectric 10, avoiding the electrodes. Humidity sensor 23
is Cr 20x v F e t O:ly S n
02* Z n Oe T i O2+NiFe2O
4. Electrolyte systems using composite metal oxides such as Al2O□, MCr20z, M, SnO<, etc., MgC:r204-TiO□-based ceramics, lithium chloride, etc., PAPA (
Various materials can be used depending on the required characteristics, such as organic materials using P-aminophdoracetylene) and the like.

Furthermore, the dielectric IO is provided with a heater 21 as a power generator, which is made of a resistance heating element using carbon, Ni.Cr, 91, or the like.

The output of the humidity sensor 23 is given to a microcomputer 22 as a control means, and the microcomputer 22 controls power input to the heater 21 based on the output from the humidity sensor 23. It has become.

The dielectric 10, buried electrodes 11, 12, and exposed electrodes 13 will be described in detail below, including their materials.

The dielectric IO is an inorganic dielectric material with high discharge resistance, such as glass, ceramic, oxides such as SiO□, MgO, and AI□03, or nitrides such as silicon nitride (S!:+Na) and aluminum nitride (AIN). In this example, it is a long member with a rectangular cross section.

The electrodes 11, 12 embedded in the dielectric 1O are arranged parallel to the bottom surface of the dielectric (the surface facing the target/charging member 2) and equidistant therefrom in the figure. This is not essential or preferred for manufacturing reasons. The buried positions of the buried electrodes 11 and 12 are set at positions where, when an alternating 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 corrosion does not occur, so that high durability can be maintained even when the above materials are used.

The distance between the buried electrodes is preferably 1 gem or more, particularly 3 to 200 p-ta, in consideration of dielectric strength.

The dielectric 10 may be integrated in this embodiment, or may be a two-layer dielectric joined at the upper surface or lower surface of the dielectric 10 and/or the buried electrode 11. In this case, the materials of each layer may be the same or different. especially,
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 an organic dielectric material. may 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 1 gm or more, 50 gm or more.
It is preferably 0 gm or less, particularly 31 Lm or more and 200 grn or less. In this embodiment, the bare electrode 13 is fixed to the bottom surface of the discharge device 1 in which discharge is generated by the alternating current voltage. A temperature increasing power source 20 is also connected to the exposed electrode 13.

The material of this electrode 13 is a conductive metal with high corrosion resistance and oxidizability, such as Ti, tri, Cr, Te, M
o, Fe, Go, Ni.

High melting point metals such as Au and Pt, alloys containing these metals, or oxides are used.

Its thickness is 0.1-100, preferably 0.2-20
The width of the layer is IILm or more, preferably lO to 500 l. The position of the bare electrode is near the end of the discharge generation region 15, and the AC applied voltage that causes discharge initiation between it and any of the buried electrodes (11 and 12) is higher than the predetermined discharge initiation voltage. It's the location. Here, the vicinity of the discharge area refers to the vicinity including the outside and inside thereof, and it is preferable to be outside, but even if it is inside, it is functionally satisfactory as long as it is near the end of the discharge area.

In this particular embodiment described above, discharge is performed as follows. Note that the discharge device l of this embodiment can be used to neutralize or charge the liquid gland/charging member 2 consisting of the dielectric layer or photoreceptor layer 17 and the conductive substrate 18.
Since the principles of electrification removal and charging are the same, only the case where electrification is performed will be explained.

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 illustrated discharge device fal (the electrode 11 and the same 12 to which the AC voltage is applied) to be applied between the buried electrodes 11 and 12. With reference numeral 1, centering on the part facing the vicinity of the electrodes (a plane substantially parallel to the line connecting
A discharge is performed in a single region indicated by 5, and positive and negative ions are generated alternately. However, since a bias voltage is applied to the exposed electrode 13 by the bias power supply 19, ions of a desired polarity among the ions are extracted toward the member to be charged 2, and the member to be charged 2 is not charged. Ru. Note that the polarity of the extracted ions is determined by the polarity of the applied bias voltage.

Further, the heater 21, which is one power generator, is powered on by a command from the microcomputer 22 to raise the temperature of the dielectric 10.

That is, the microcomputer 22 constantly monitors the output from the humidity sensor 23 and controls the heater 21. Here, when the humidity changes and the amount of moisture in the air increases, the output current from the humidity sensor 23 changes. The microcomputer 22 has a humidity sensor 23
When the current value input from the microcomputer changes and exceeds the recorded current value recorded in the microcomputer, power is applied to the heater 21 to raise the temperature of the dielectric 10 and remove the temperature around the discharge device. The recording current value is a current value output from the humidity sensor under the highest humidity condition within the humidity range in which discharge can be performed satisfactorily. Furthermore, the recording current value changes depending on the specifications of the discharge device, and suitability conditions differ depending on the type of device.

The operation of the microcomputer 22 described above continues even during discharging, and it turns on and off power to the heater 21 according to the environment.
The cut is always controlled.

In the above-mentioned embodiments, the humidity sensor is mounted on the current-visiting body of the discharge device, or in the present invention, the humidity sensor may be provided on the dielectric by adhesive, or even if the humidity sensor is mounted on the dielectric to hold the dielectric. A humidity sensor may be provided on the holding body.

In addition, the heater is controlled by a microcomputer.
The amount of heat generated can be controlled by stopping the supply of current or controlling the amount of current.

(Effects of the Invention) As described above, according to the device of the present invention, the discharge device is provided with a humidity detection means, and the heating element is controlled based on the output from the humidity detection means, thereby efficiently controlling the electrodes of the device. It becomes possible to dehumidify the surrounding area, reduce power consumption, and achieve the effect that uniform and stable discharge can be performed quickly and efficiently under a wide range of environmental conditions.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a device according to an embodiment of the present invention. 1...Discharge device 10...Dielectric 11.12...Embedded electrode 13... ...Bare electrode 21...
...Heating element (heater) 22...
...Control means (microcomputer)

Claims (1)

[Scope of Claims] A dielectric body in which at least two electrodes for applying an alternating current voltage are embedded is provided with an exposed electrode for applying a bias voltage, and a heating element for heating the dielectric body and a humidity sensor for detecting humidity. A discharge device comprising: a detection means; and a control means for controlling the heating element based on the output of the humidity detection means.