JPS63208070A - Corona discharger - Google Patents

Abstract

PURPOSE:To decrease the amt. of ozone to be generated so that the life of a titled device is extended and the cost thereof is reduced by using an active carbon fiber material to constitute the side surface of a shield. CONSTITUTION:At least the inside surface 9 of the shield is constituted of the active carbon fiber ACF10. O3 13 formed in a corona plasma area 12 on the surface of an electrode wire 11 is decomposed by the AFC10. The amt. of O3 to be released from a corona discharger which is the source for generating O3 is, therefore, decreased and the formation of NOx is decreased. Gaseous Si (silicone oil vapor, etc.) which is the cause for the resulted product of discharge consisting of SiO2 grown on the surface of the electrode wire 11 is adsorbed to the active carbon fibers 10, by which the deterioration of the electrode wire 11 is retarded. The working life of the corona discharger is thereby extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a corona discharge device used in electrophotographic copying machines and the like. More particularly, the present invention relates to a corona discharge device that produces less ozone, has a long operating life, and is low cost.

[Prior Art 1 An example of a conventional electrophotographic copying machine is shown in [Omitted (1)] in FIG.
4 Explain based on the fire diagram. In the copying machine shown in FIG. 8, there is a glass document table 22 on which the document 21 can be placed on top of the cabinet 23, and a platen cover 39 that covers the document 21.
are arranged. Below the document table 22, first mirror units 1 to 10 each include a light source 26 and a first anti-fouling mirror 27.
An optical scanning table consisting of 25 is provided so as to be movable in a straight line to the left and right in the drawing, and a second mirror unit 24 to keep the optical path length between the document scanning point and the photoreceptor constant changes the speed to the first mirror unit 1. The reflected light from the document table 22 side is incident on the photosensitive drum 40 as an image carrier through the lens 2B and the reflecting mirror 29 in a slit shape.

Around the photosensitive drum 40 are a charging corotron (corona discharge device) 41, a developing bag @ 44, a transfer corotron (corona discharge device) 45, and a peeling corotron (corona discharge device) 4.
6. A static eliminating corotron (corotron discharge device) 47 and a cleaning device 48 are provided. The photoreceptor drum 40 rotates in the direction of arrow A, and after the surface of the drum is charged by the charging corotron 41, it is exposed to image light by the optical system described above to form an electrostatic latent image. This latent image is visualized with toner by a developing device 44.

On the other hand, the paper 35 fed from the paper feed cassette 33 via the paper feed rollers 34 and 36 has its toner image on the drum 40 transferred by the transfer corotron 45, and is then peeled off from the drum by the peeling corotron 46, and then transferred to the fixing section 32. The image is fixed and discharged onto the tray 37. Also, after the image is transferred to the photoreceptor drum, residual charges are removed.
It is cleaned by the cleaning device 48 and sent to the next copy cycle υ11.

In such an electrophotographic copying machine, in order to uniformly charge the photoreceptor (charging corotron 41), to transfer the toner image (transfer corotron 45), and to peel off the paper (separation corotron/'I6), A corona discharge device is used to remove residual charges (electrostatic discharge roller) (Ron 47).

[Problems to be Solved by the Invention] The discharge device has a configuration as shown in FIG. 9. In other words, the electrode wire 6 where the high voltage power source performs corona discharge
The electrode wire 6 is surrounded by a conductive shield 5 that is electrically grounded, and is disposed adjacent to the grounded photosensitive drum 1 . Corona discharge is performed when the electrode wire 6 is brought close to the photoreceptor 1 and a sufficiently large voltage is applied to the electrode wire 6, causing destruction of ions in the air between the electrode wire 6 and the photoreceptor. . As a result of the discharge, charged ions formed around the electrode wire 6 flow toward the grounded photoreceptor drum 1, adhere to the surface of the photoreceptor, and charge the surface of the photoreceptor to a relatively high potential.

In this type of corotron, corona discharge is performed in the atmosphere, so in addition to the ions mentioned above, ozone O3 is formed as a fermentation organism as a result of inelastic collisions between oxygen 02 and electrons. released.

Since this 03 has strong reactivity (oxidizing power), it is not only toxic to the human body, but also accelerates the deterioration of the interior of the copying machine, such as the photoconductor M of the photoreceptor.

Conventionally, as a method for reducing this 03, for example, i
) A method of reducing 03 by suctioning 03 generated in colo 1 to ron and passing it through a filter carrying decomposed substances during the discharge process (Utility Model No. 56-
No. 45851, No. 56-1'70459), ii) A method of reducing the total discharge current of the corotron (JP-A-55-120050 @>, 1ii) Fixing decomposed substances to the surface of the corotron shield 03 A method of reducing it by decomposing it as soon as it occurs (
Many methods have been proposed, such as Japanese Patent Publication No. 52-1670 @, No. 53-33852).

However, none of these methods was satisfactory in terms of decomposition or reduction efficiency of 03, life span, etc.

That is, in the method ii) above, it is possible to reduce 03 to large rlJ.
In method ii), the decomposed substance and L/T, for example Mn
, v, Fc, Cu, Ni, Cr, co, 7n, etc., oxides of these metals, activated carbon, or substances in which Ag, Pt, Pd, etc. are supported on activated carbon are used, but none of them are effective. It has some drawbacks such as decomposition efficiency, lifespan, and peeling of decomposed substances. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and to provide a corona discharge device that emits less ozone and has a long operating life.

[Means for Solving the Problems] As shown in FIG.
iber: Hereinafter abbreviated as ACF. >10, by decomposing 0313 generated in the corona plasma region 12 on the surface of the electrode wire 11 with ACFlo, the amount of 03 released from the corona discharger, which is the source of 030, is reduced by 1-1. At the same time, the generation of NOx is reduced, and the deterioration of the electrode wire 11 is prevented by adsorbing Si-based gas (such as silicone oil vapor) on the activated carbon fiber 10, which causes discharge products made of SiO2 that grow on the surface of the electrode wire 11. This slows down the process and extends the operating life of the corona discharger.

The ACF used in the corona discharge device of the present invention can be prepared by any conventionally known method! A can be built. For example, after oxidizing polyacrylonitrile fibers, or pre-oxidizing and carbonizing cellulose fibers, pitch fibers, and phenolic resin fibers, an activating gas with a moisture content of 5Vo1% or more, preferably B□vo+% or more (for example, water vapor,
It is produced by activation using carbon dioxide, ammonia gas, a mixture thereof, etc.) in a high temperature atmosphere of 350° C. or higher for 1 minute to 3 hours.

However, ACF's "IA)Ei" is not limited to the above method.

The ACF used in the present invention has an adsorption surface area of 300 to 20
00Trt/g. Such ACF has an equilibrium adsorption capacity about 1.5 to several times higher and an adsorption rate of 10 to 100 times higher than that of granular activated carbon.

This J, eel activated carbon 1ili fiber is inexpensive! It is possible to create A-shaped products (i.e., unlike baked crystals of powdered activated carbon, there is almost no dusting due to desorption of the activated carbon, and by utilizing the properties of fibers, it can be made into nonyl-like, paper-like, honeycomb-like, and resin-like forms. E”
It can be easily processed into a strip or a coat (prepared by coating with a binder mixed with fibers).

In the present invention, (i) 8CF can be used as an intermediate suspension, and in addition, (ii) a metal, (iii) a substance having catalytic activity such as a metal oxide, or (iv) a metal chelate compound can be added to the ACF. Supported materials can also be preferably used, and corona discharge devices constructed from these preferred materials are also a subject of the invention.

Examples of metals that are adhered and supported on ACF include Ti.
SV, Cr, Mn, Fe, Co, Ni, Cu, Zr,
Nb, Mo, Ru1Rh, PdXPt.

Examples include one type of A(], Sn, W, Pb, etc., or an alloy thereof.

Further, as the metal oxide, for example, one of the above metal oxides is used.
A species or two or more species may be mentioned.

In addition, examples of metal chelate compounds include Cr, M
n, Co, Ni, Cu, Zn, Cd, p(1
, Ag, etc., such as ethylenediaminetetraacetic acid 1 (EDTA), nitrilotriacetic acid (to NT), trans-1,2-cyclohexacyaminetetraacetic acid M
(cy-DTA>, diethylenetriaminepentaacetic acid (D
TPA>, triethylenetetraminehexaacetic acid (TTHA)
), Glycol Ether Diamine Tetra Vinegar M (GETA
), iminoniacetic acid (IDA), N,N-ethylenebis(γ-〇-hydroxyphinyl)glycine (EHPG)
and other metal chelate compounds coordinated with chelating agents such as complexans.

All of these types of A Cl- can efficiently decompose 03, have a long life, and effectively adsorb harmful gases other than 03. Also, since it is conductive, it can be used as an electrode.

FIG. 1 shows an embodiment of the present invention in which at least the inner surface of the shield of a corotron is made of ACF as described above. In the example shown in Figure 1, ACF paper is glued onto an aluminum shield and processed so that the inner surface of the corotron is made of 80F.

Another example of a corona discharge device in which at least the inner surface of the shield is made of ACF material is shown in FIG.
In addition to the corotron shield made of CF material only, the shield made of corrugated pole-shaped 80F16 as shown in Figure 3, and the shield reinforced with metal wire as shown in Figure 4. One made of ACF felt 17, one made of ACF 18 with the shield sandwiched between metal plates as shown in Figure 5, and one made of ACF 19 with the four corners of the shield reinforced with plastic as shown in Figure 6. An ACF whose shield is reinforced with metal mesh as shown in Figure 7.
20 and so on.

Hereinafter, (i) ACF alone, (ii) metal-supported ACF, (
A corona discharge device using iii) gold FJ2 compound-supported ACF and (iv) metal chelate compound-supported ACF will be sequentially explained.

(i) ACF alone After ACF is pulverized, it is mixed with cellulose fibers such as fibrillated bulb fibers and illumination pal fibers, and then paper-made using a normal wet paper-making method to obtain 1 q of ACF paper. This ACF
The paper was attached to an aluminum shield with a thickness of 1 m and an AC paper with a thickness of 0.1 # using adhesive. When this corotron and a corotron made only of aluminum were compared in terms of 03ffi emitted from the exhaust fan of a copying machine when positive discharge, negative discharge and AC discharge were performed, the corotron of the present invention had a 03ffi of 03ffi emitted from the corotron made of an aluminum shield. was reduced to 23% for all positive discharge, negative discharge, and AC discharge.

Next, as shown in Fig. 2, for a corotron shield made of 1m thick 8C paper only, we compare the 03 base emitted from the exhaust fan of a copying machine with a corotron made of stainless steel shield. 03 amount is positive discharge,
Both negative discharge and AC discharge decreased to 14%. It has been found that when the ACF is provided not only on the inner surface of the shield but also on the entire surface, 03ffl is further reduced than when the ACF is provided only on the inner surface of the shield.

In addition, the output level that is adjusted to exhibit stable discharge characteristics at d3 in 1 tron is set to 20% of the unevenness of the discharge current in the axial direction of the discharge wire, and then When we looked at the number of copies per A5 in the above-mentioned example using positive discharge, the number of copies made by the corotron made of stainless steel shield was 55,000 copies, whereas the number of copies made by the corotron made of ACF paper shield according to the present invention was 55,000 copies. 95,000 copies were sold. Such a difference causes deterioration of the discharge characteristics on the surface of the electrode wire due to discharge.
It was confirmed using an electron microscope that the amount of growth of the discharge product consisting of 2 was due to less crawling of the corotron according to the present invention. The reason for this is presumed to be that ACF adsorbs and reduces Si-based gas, such as dimethylsiloxane gas, which is a source gas for SiO2 formation.

In addition to the above-mentioned characteristics, like 03, nitrogen oxides (NOx) released from the corotron due to corona discharge also accelerate the deterioration of parts within the copying machine, but the corotron according to the present invention can also reduce the amount of NOx. was confirmed.

Regarding the above example, NOx was measured using a discharge device for measuring NOx concentration.
When comparing the suspension, the Noxffi has a positive discharge of 45%, compared to the corotron made of an aluminum shield, with the corotron made of a shield attached with ACF.
With negative discharge, it decreased to 66%. This decrease in NOx is considered to be due to adsorption, unlike the decomposition in the case of 03.

In addition, tests were also conducted on a known shield coated with activated carbon fine powder as a corotron for reducing 03, but the one using the ACF of the present invention did not have the problem of strength decreasing over time. Although no desorption of CF was observed, some of the products coated with activated carbon powder peeled off during handling, making them unusable.

When we investigated other corotrons with the configurations shown in Figures 4 to 7, we found that the amount of 03 emitted from the exhaust fan of the copying machine was due to the shield made of aluminum or stainless steel [1].
It was reduced to 10-20% compared to TRON.

(ii) Metal-supported ACF As a method for supporting metals on ACl:, ACF is impregnated in an aqueous solution of a total compound such as a metal salt, and if necessary, a precipitant is added to precipitate the metal compound on the ACF. In addition to the general method of reducing active metals to fibers by reducing them using formalin, formic acid, NaBH4, hydrogen gas, etc., electroplating is performed on ACF using the conductivity of ACl as an electrode. A method in which metal is attached using a metal plate or an electroless plating method can also be used.

The amount of metal supported is not particularly limited as long as it can be supported, but a practical amount is 0.001 to 30% by weight, preferably 0.1 to 2.0% by weight, preferably 11% by weight based on ACF.

As an example, we used ACF paper on which A() was supported as the metal, and with the configuration shown in Figure 2, we used an adhesive to paste Ag-supported ACF paper with a thickness of 011# on aluminum with a thickness of 1 mm. Created a Shitacorotron.

Note that AIIJ-supported paper is produced, for example, by mixing pulverized AC with fibrillated cellulose fibers such as wood pulp fibers and pulp fibers, and then forming the mixture using a normal wet paper-making method.

This ACF paper is immersed in a silver nitrate solution for calculation.

Next, after making the mixture alkaline with caustic soda, formalin is added dropwise while stirring. Add excess formalin and discharge for 1 to 2 hours to reduce and spread silver on ACF paper. After reduction,
ACF paper is filtered, washed with water, and dried at 100-110°C.

At this time, the amount of silver spread on the ACF paper can be varied by adjusting the amount of silver nitrate solution added.
As one example, 2% Act was supported.

This A(]-supported ACF paper (thickness o, i,) was attached with adhesive to an aluminum shield with a thickness of 1# as shown in Figure 1. ]
A comparison was made of the 03W emitted from the exhaust fan of a copying machine when the corotron was negatively discharged using a corotron with a shield attached to ACF paper that does not carry aluminum and a corotron with a shield made only of aluminum. Compared to Coro1 to Ron (0% decomposition rate 0%), which consist only of shields, the decomposition rate of 03 is 7 for ACFC aluminum shield Corotron.
7%, A (] Supported ACF paper affixed aluminum shield]
In Rotron, it was 84%. Also, A that does not support metal
In the shield Rorotron with CF paper attached, the 03 decomposition rate decreased to 44% after copying 50,000 copies, whereas in the Corotron 1'' with A(] carrying ACF paper attached, it remained at 55%.

In addition, the permissible output level for achieving stable discharge characteristics for Colo 1 to Coron is defined as the level where the unevenness of the discharge current distribution in the axial direction of the discharge wire reaches 20%, and the When we looked at the number of copies made in the above example under positive discharge, the number of copies was 55,000 for the corotron made of an aluminum shield, whereas the number of copies made by the corotron made of the Ag-supported ACF paper affixed shield according to the present invention was 55,000. 10.55 million copies were sold.

In addition, when comparing the × of NOxI using a discharge device for measuring concentration, it was found that the corotron, which is made of a shield with ACF paper attached to it, has a Noxffi of 42% in positive discharge, and 42% in negative discharge, compared to the corotron, which is made of aluminum shield. It decreased to 54%.

Furthermore, the ACF paper was reduced with an alkaline hydrazine solution using a chloride solution of platinum chloride or palladium chloride, so that 1% by weight of pt or Pd was supported on the ACF paper. Using these, the shield is made of cardboard-like ACF 16 as shown in Figure 3, the shield is made of ACF felt 17 reinforced with metal wire as shown in Figure 4, and the shield is made of ACF felt 17 reinforced with metal wire as shown in Figure 5. as shown in Fig. 6, formed of ACF19 with the shield 4 reinforced with plastic, as shown in Fig. 7, and ACF20 with the shield reinforced with metal mesh as shown in Fig. 7. A model formed using the following was fabricated and tested. 03f emitted from the exhaust fan of any Corotron copier
fi was reduced to 10 to 15% compared to a corotron with a shield made of aluminum or stainless steel, which is higher than that of AC and F without metal support. In addition, the decomposition rate decreased significantly over time.

(iii) Metal oxide-supported ACF A method for supporting metal oxides on ACF is, for example, by impregnating ACF with an aqueous solution of metal chlorides, nitrates, etc., and then baking to convert the metal salt into metal oxide. ACF is produced by coating or by impregnating ACF raw material fibers, such as CELL D's fiber, with a solution of metal chlorides and nitrates, then firing and activating it.
At the same time, the metal salt is converted into a metal oxide, or the metal salt is further dissolved in the spinning solution, the yarn is delivered after mixing, and fired and activated, or the aqueous solution of metal nitrate, 5A acid salt, etc. is impregnated with ACF. After that, sodium hydroxide is added to form a hydroxide, which is then heated to form a metal oxide.

Note that the metal oxide supported on ACF in the present invention is not limited to a stoichiometric oxidation state, but may be one in an unsaturated or supersaturated oxidation state, or one containing a hydrous acid group oxide.

The amount of these metal oxides supported is not particularly limited as long as it can be supported, but o, ooi ~ 30
A small amount %, preferably 0.1 to 20ff1m% is practical.

Among the metal oxides listed above, manganese oxide is particularly preferred.

Next, as an example, using ACF paper loaded with cobalt oxide, we pasted a 0.1# thick ACF paper loaded with cobalt oxide onto a 1-thick aluminum plate with the configuration shown in Figure 1. I made a corotron.

The cobalt oxide-supported ACF paper was manufactured as follows.

Wood pulp fiber made by fibrillating pulverized ACF,
After mixing with cellulose fibers such as pulp fibers, ACF paper was first obtained by making paper using a normal mixed paper making method.

Next, this ACF paper was immersed in an h1 amount of cobalt nitrate solution, then immersed in a NaOH solution, and then washed with water. After pre-drying this, it was heated at 110°C to support 15% by weight of cobalt oxide on ACF paper.
CF paper was obtained.

In addition, ACF paper was immersed in a calculated manganese nitrate solution and then treated in the same manner to support 15% manganese oxide.
! 7. :A CF paper (thickness 0.1 mIn>17) was coated with 1# thick aluminum as shown in Figure 1.
Coro 1 to Ron were prepared.

When corotrons of the above two scales, similar structure with ACF paper that does not carry metal oxides attached], and a shield made of aluminum [11~rons are used to cause a negative discharge of Coro1~rons] The amount of 03 released from the exhaust fan of a copying machine was compared.

Compared to a corotron consisting only of an aluminum shield (03 decomposition rate 0%), the 03 decomposition rate was 77% for the ACFT shield corotron, 83% for the corotron with cobalt oxide-supported ACF paper pasted, and 83% for the corotron with manganese oxide-supported ACF paper pasted. It was 81%. Further, the 03 decomposition rate after copying 50,000 sheets was 44% for the ACFC shielded corotron, 60% for the corotron attached to cobalt oxide-supported ACF paper, and 78% for the corotron attached to manganese oxide-supported ACF paper.

In addition, the permissible output level for the corotron to exhibit stable discharge performance for 1 hour is set until the percentage of unevenness in the discharge current distribution in the axial direction of the discharge wire reaches 20%, and until then the copying machine I checked the number of sheets with positive discharge.

As a result, the number of sheets was 55,000 sheets for a corotron made only of aluminum shields, 110,000 sheets for a corotron with cobalt oxide sustained ACF paper affixed, and 120,000 sheets for a corotron affixed with manganese oxide-supported ACF paper.

Furthermore, when we compared the amount of No using a discharge device for NOx a measurement, we found that the corotron made of cobalt oxide-supported A CFC paper shield had 30% Noxffi in positive discharge compared to the corotron made of aluminum shield.
, it decreased to 49% in negative discharge. In addition, for a corotron consisting of a shield pasted with ACF paper carrying manganese oxide, 33% for positive discharge and 5% for negative discharge.
It decreased to 7%.

The above cobalt oxide supported ACF, manganese 1112 oxide supported ACF, 8C [Felt with CuCF2.2+-
8C impregnated with an aqueous solution of 120, dried at 100'C, fired at 800'C in a nitrogen stream for 1 hour, and attached with oxidized steel [shielded using felt as shown in Figure 3] is made of corrugated ACF 16, as shown in Fig. 4, the shield is reinforced with metal wire and made of ACF felt 17, and as shown in Fig. 5, a shield metal plate is sandwiched between ACF sheets. , and A with the shield 4 corner reinforced with plastic as shown in Figure 6.
We created one made of ACF 20 with a shield reinforced with a metal mesh as shown in Figure 7.The amount of 03 emitted from the exhaust fan of the copying machine in both corotrons is aluminum. Compared to a corotron with a shield made of stainless steel, the decomposition rate was reduced to 10 to 15%, which is higher than that of ACF without metal support.The decomposition rate also decreased significantly over time.

(iv) Metal chelate compound-supported ACF Metal chelate compound-supported ACF can be obtained by any method such as a method in which a solution or dispersion of a metal chelate compound is firmly attached to ACF and dried.

Metal chelate compounds are used in ACF at approximately 30% of the total product.
It can be carried up to. When this AC is used, it is supported in an amount of about 0.01 to 20% by weight, preferably about 2 to 15%. If the loading is less than 0.01%, the effect will be insufficient, and if it is more than 20%, the loading will be so large that the apparent specific surface area will become small and the effect will drop sharply.

The chelate compound is supported so that the specific surface area of ACF remains at least 50%, preferably at least 70%, of the specific surface area before being supported.

Next, as an example, nickel ethylenediaminetetraacetate (E
DTA-Ni) supported ACF paper (thickness 0.1 mtn>
A corotron was fabricated by attaching the sample to an aluminum shield with a thickness of 1 mm as shown in FIG. EDTA-Ni supported ACF paper is produced by mixing pulverized ACF with cellulose fibers and making it using a normal mixed papermaking method to obtain ACF paper.
This was immersed in a calculated amount of EDIA-Ni solution, pre-dried, and then 11
Dry at 0°C [EDI A-Ni 5%
The ACF-paper carried is 17.

A corotron with EDIA-Ni-supported ACF paper attached, a corotron with a similar structure but with a shield pasted with ACF paper that does not support EDTA-Ni, and a corotron with a shield made only of aluminum were used.
A comparison of the 03M emitted from the exhaust air of a copying machine when the RON is negatively discharged reveals that the 03 decomposition rate is 0% compared to the CO[I-tron (03 decomposition rate 0%), which is made only of aluminum shields. The failure rate was 77% for the paper-attached ACF shield corotron, and 81% for the EDTA-Ni-supported ACF paper + i-shield corotron. Also 5
After 10,000 copies, the decomposition rate of 03 was 44% for the AC paper-attached (-1 shield corotron) and 52% for the EDTA-Ni-supported ACF paper-attached shield corotron.

In addition, the permissible output level for the corotron to exhibit stable discharge characteristics is set until the percentage of unevenness in the discharge current distribution in the axial direction of the discharge wire reaches 20%, and until that point the copying machine in the copying machine When looking at the number of sheets under positive discharge for the above embodiments, the number of sheets was 100,000 sheets for the corotron comprising the EDTA-Ni-supported ACF paper-attached shield according to the present invention, compared to 55,000 sheets for the corotron comprising the aluminum shield.

In addition, when comparing the amount of NOx using a discharge device for measuring NO concentration, it was found that the corotron made of a shield with EDTA-Ni-supported ACF paper pasted had 44% NOxffl in positive discharge and 44% in negative discharge compared to the corotron made of aluminum shield. It decreased to 56%.

Furthermore, EDTA-Co supported ACF was obtained by spraying an EDTA-Co solution onto ACF, and using this, a shield was formed from cardboard-shaped ACF16 as shown in Figure 3, and a shield was formed as shown in Figure 4. When the shield is made of ACF felt 17 reinforced with metal wire, as shown in Figure 5, the shield is made of metal plate sandwiched between ACF felt 18, and as shown in Figure 6, the shield 4 is made of plastic. The shield was made of 80F19 reinforced with metal wire, and the shield was made of ACF20 reinforced with metal wire as shown in FIG. Both Corotrons are copy machines.
The air emitted from the fan is EDTA-3 compared to the shielded Corotron made of aluminum and stainless steel.
It decreased to 10 to 15%, which is higher than the case of AC without Co support.

In addition, the degradation rate decreased significantly over time.

[Effects of the Invention] In the present invention, at least the shield surface is made of activated carbon fiber (A
The present invention provides a corona discharge device constructed of CF>, which has features such as extremely low ozone emission, the ability to reduce nitrogen oxides, and no deterioration in performance over a long period of time.

[Brief explanation of the drawing]

1 to 5 are cross-sectional views of an example of an ACF installed corona discharge device according to the present invention, and FIGS. 6 to 7 are a part of an example of an AC installed corona discharge device according to the present invention, respectively. FIG. 8 is a schematic view of an example of an electrophotographic copying machine, and FIG. 9 is a partially cutaway perspective view of a corona discharge device provided adjacent to a photoreceptor drum. - Photosensitive drum: 2, 14... Photoconductive insulating layer; 3... Conductive layer: 4... Corona discharge device; 5.
...Shield member; 6,1'l...Corona discharge electrode wire; 7...Electrical connector: 8...Voltage power source; 9
...Aluminum shield: 10...ACF paper;
12... Corona plasma pirate; 13... Ozone; 1
5...ACF paper; 16...Corrugated paper-like ACF
:17...Metal wire reinforced ACF felt: 18...
Metal plate support ACF paper; 19... Plus deck reinforcement A
CF paper; 20...wire mesh reinforcement A C1 paper; 21...
Original; 22... Original table; 23... Cabinet; 24° 25... Mirror unit: 26... Light source; 27... Mirror; 28... Lens: 29.
... Reflection mirror; 30 ... Heating fixing roll: 31
...pressure roll; 32...fixing section; 33...
Paper feed tray; 34... Paper feed [1-ru; 35... Paper; 36... Timing roll; 37... Paper output tray; 39... Plantain cover; 710...
・Photoreceptor drum; 44...Developing device: 45...Transfer corotron; 46...Peeling] [211-ron;
47... Static eliminator [1 tron; I! '18... Cleaning device + 1419... Cleaning blade. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1) A corona discharge device characterized in that at least the inner surface of the shield is made of an activated carbon fiber material. 2) Corona discharge device according to claim 1, wherein the activated carbon fiber material carries a metal. 3) Corona discharge device according to claim 1, wherein the activated carbon fiber material carries a metal oxide. 4) The corona discharge device according to claim 3, wherein the metal oxide is manganese oxide. 5) Corona discharge device according to claim 1, wherein the activated carbon fiber material carries a metal chelate compound.