JPS62296174A - Electrifying device - Google Patents

Abstract

PURPOSE:To make spark discharge to hardly takes place so as to improve the current discharging effect and maintainability and make the life of an electrifying device longer, by providing an electric charge receiving body beside a solid-state electrode having a volume resistivity of 10<6>-10<13>OMEGAcm with a vacant space between them under a condition where the receiving body is faced to the electrode and connecting a DC power source between them. CONSTITUTION:A metallic electrode 2 is stuck to a solid-state electrode 1 having a volume resistivity of 10<6>-10<13>OMEGAcm with a conductive adhesive and an electric charge receiving body 3 is provided on the other side of the electrode 1 with a vacant space of <=1mm between them under a condition where the receiving body 3 is faced to the electrode 1. When a direct current is supplied to the electrode 1 from a DC power source 4, the vacant space between the electrode 1 and receiving body 3 is ionized and (+) ions are made to flow to the electric charge receiving body 3 and the receiving body 3 is electrostatically charged. If the electric charge receiving body 3 is used as a photosensitive body and the electrode 1 as an electrifying device in a copying device and a 3KV direct current is supplied to the electrifying device 1, no spark discharge takes place and the photosensitive body 3 is uniformly electrostatically charged, since the electrifying device 1 is a high-resistance body and its discharge is stable. Therefore, spark discharge is made to hardly occur with a small-sized device and its current discharging effect and maintainability can be improved. As a result, its life can be made longer.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Detailed Description of the Invention Field of Industrial Application This invention relates to a charging device that can be applied to copying machines and printers that apply an electrophotographic process.

2. Description of the Related Art Conventionally, an electrophotographic apparatus such as an electrophotographic copying machine has a 24th
Corotron charging devices such as those shown in Figures 1 and 25 are commonly used.

The above-mentioned charging device has an insulating block b provided at both ends of a shield case a having a rectangular cross-section, and a discharge wire cf is stretched between the insulating blocks b so as to be located approximately in the center of the above-mentioned shield case a. With the configured configuration, a high voltage of ±4000 to ±gooov is applied to the discharge wire C so that corona discharge occurs between it and the charge receptor d such as a photoreceptor. Ions generated by this corona discharge adhere to the charge receptor dlc and charge it.

In addition, the shield case a surrounding the discharge wire C has a function of strengthening and stabilizing the electric field formed on the surface of the discharge wire C by maintaining a certain spatial distance between the shield case a and the discharge wire C. There is.

Problems to be Solved by the Invention The charging device configured as described above requires special measures to stretch the discharge wire C with low mechanical strength between the insulating blocks b, resulting in high cost. High (Naruto K
Also, the dispersion wire C is easily broken due to vibration during use, so maintenance is troublesome as it needs to be replaced frequently.

Another problem is that during discharge, current flows through the shield case aK in addition to the charge receptor d, which increases the discharge current.As a result, the high-voltage power supply becomes larger and more expensive, and the increased discharge current generates less ozone. There are also problems that can cause pollution of the surrounding environment.

Furthermore, in order for the charging device to operate stably, there must be a sufficient distance between the discharge wire C, the shield case a, and the charge receptor d.

That is, the ionization region of corona discharge is within a range of 1 to several micrometers in the radial direction from the surface of the discharge wire C, and the space other than this region up to the shield case a and the charge receptor d is filled with air during discharge. This is a drift region in which ionization does not occur and only ions with polarity in one direction move, and the spatial impedance is higher than that in the ionization region.

A stable corona discharge can be maintained only when this drift region has a sufficient distance.

However, in an attempt to make the charging device more compact, if the discharge wire C is placed too close to the charge receptor d or if the distance from the discharge wire C to the shield case a is reduced, the ionization region expands and the spatial impedance decreases. As a result, a spark discharge occurs and damages the charge receptor d, etc.
In the conventional charging device described above, there is a limit to miniaturization.

On the other hand, as shown in Japanese Patent Publication No. 40-22713, another charging device uses an electrode in which an insulating thin film is partially formed on the surface of a metal, and the distance between the metal substrate having photosensitive paper and the electrode is
It has been disclosed that a photosensitive paper is charged by applying a voltage of 100 OV or less.

However, in this case, the electrode photosensitive paper and the metal substrate are stacked and charged, and there is a problem that dielectric breakdown is likely to occur when the applied voltage becomes low. Further, such contact type electrodes are not suitable for copying materials using reusable photoreceptors.

Furthermore, as an example of another charging device, a method and apparatus for placing an induction electrode and a discharge electrode facing each other with a dielectric between them, and applying an alternating current voltage between the two electrodes to generate positive and negative ions from the discharge electrode is disclosed in Japanese Patent Application Laid-Open No. 1983-1999. No. 53537, and a similar structure is disclosed in Japanese Patent Application Laid-Open No. 57-205757. These devices have the advantage of being relatively compact and being able to be set up at a predetermined distance from the charge receptor, but on the other hand, their configuration means that AC voltage is superimposed on DC voltage, so they require two power sources. However, since the amount of ozone is large and the creeping streamer is used, there is a problem that the amount of light emitted is large.

This invention was made for the purpose of improving the problems of the conventional charging device described above.

Means and Effects for Solving the Problems The present invention provides a charging device comprising a solid electrode of a high electrical resistance having a volume resistivity of 106 to 1 rΩ and a voltage applying electrode formed on one side thereof. is very easy,
It has the characteristics of being small and robust.

Embodiment 1 FIG. 1 is a basic configuration diagram of the charging device of the present invention and its application as charging means. In this figure, 1 is a solid electrode of high electrical resistance with a volume resistivity of I O' to 1♂Ωα, and 2 is a conductor electrode made of metal or the like that is closely adhered to one side of the solid electrode 1, for example, the back surface. It is connected to a power source 4 to apply a voltage to the solid electrode 1. A charge receptor 3 faces the other side of the solid electrode 1 with a gap of less than 1 inch in between, and forms, for example, a photoconductive layer on a conductor substrate, is grounded to the substrate, and is connected to the solid electrode I. Corona discharge occurs intermittently.

That is, when a DC voltage is applied through the solid electrode IK metal electrode 2, ionization of air occurs in the gap between the solid electrode 1 and the charge receptor 3.

If the positive polarity side of the DC power source 4 is connected to the metal electrode 2, + ions flow to the charge receptor 3 side and charge it.
- ions or electrons reach the solid electrode 1 side and are neutralized.

In addition, since the solid electrode 1 has a large resistance, the discharge is stable and does not lead to spark discharge, and the use of a high electrical resistance material for the solid electrode 1 prevents excessive current from flowing in any part of the gap. The charge receptor 3 can be charged more uniformly.

This is considered to be because the gap between the solid electrode 1 and the charge receptor 3 corresponds to an ionization region, and the solid electrode 1 itself corresponds to a high impedance drift region.

On the other hand, FIG. 2 shows an embodiment of an electronic copying machine that employs the charging device of the present invention.To explain this next, the charge receptor 3, which has a photoconductor layer formed on an aluminum substrate, has a drum shape. First, before the image information is irradiated, the surface is uniformly charged by a charging device 21,
A document table 11 is provided above the document table 11 on which a document 10 to be copied is placed, and a light source 12 that illuminates the document 10 is provided below the document table 11. to the body 3 (where an optical system 9 is installed).

Further, the electrostatic latent image formed on the surface of the charge receptor 30 by the exposure process is transferred to a developing device 13 installed around the charge receptor 30.
After being developed into a toner image, the toner image reaches a transfer device 14 and is transferred onto a sheet 16 fed from a sheet feeding device 15.

The paper 16 on which the toner image has been transferred is transferred to a charging device 17 for peeling.
The static electricity is removed by the charge receptor 3, and the fuser 1 is peeled off from the charge receptor 3.
g, and the toner image on the paper 16 is fixed on the paper 16 by the fixing device 18. On the other hand, the untransferred toner remaining on the surface of the charge receptor 3 after the transfer process is neutralized by the pre-cleaning corotron+9 IC. , are removed from the surface of the charge receptor 30 by the cleaning device 20.

The above is the structure and operation of a copying machine that employs the electrophotographic method.
Various charging devices such as the pre-cleaning charging device 19 are used, and the charging device of the present invention is applied to these charging devices.
To explain with a diagram, the solid electrode 1 has a volume resistance of 10
A metal electrode 2 having the same width, the same length, and a thickness of 3ffi11 was adhered to this using a conductive adhesive.

Further, the metal electrode 2 is fixed to an insulated support 5 and is opposed to the solid electrode 1 and the charge receptor 3 through a gap of about 200 μm, and the metal electrode 2 is connected to a DC power supply of about +3 KV.
When applied, the charge receptor 30 surface position was approximately +80
It became 0V.

Using the charging device having the above configuration, the charge receptor 3 is uniformly charged at f!
After charging, an electrostatic latent image is formed on the surface of the charge receptor 3 through an exposure process, and this is developed into a toner image by a developing device 12, and then the paper 1 fed from the paper feeder 14 is transferred through a transfer process.
The paper 15 on which the toner image was transferred was sent to the fixing device 16, and the toner image was transferred onto the paper 15. As a result, it was confirmed that a good copy image could be obtained.

In addition, when similar experiments were conducted by changing the volume resistivity of the solid electrode 10, it was found that when the volume resistivity was less than 100 Ω, intervening discharge was likely to occur in a part of the solid electrode 1, and when it exceeded 104 Ω, the charging It was found that the power supply voltage had to be made considerably high because the necessary current could be obtained sufficiently.

Therefore, the volume resistivity of the solid electrode 10 is 106Ωα~
A range of +d3Ω is appropriate. As a material applicable to the solid electrode 1, plastic is preferable, and in order to obtain the necessary resistance value, K can be adjusted by adding an ion-conducting material.

Next, regarding the surface resistance of the solid electrode 10, if a surfactant or the like is coated on the surface of the solid electrode 10 to prevent contamination, the surface resistance may become low.

In such a case, for example, if the surface resistance of the solid electrode 1 is 10Ω
Below this, spark discharge may occur even if the bulk resistance is high.

Therefore, it is necessary to maintain at least the surface resistance of the solid electrode 10 at a value higher than 10'Ω.

Further, if the gap between the solid electrode 1 and the charge receptor 3 exceeds 500 μm, electric discharge may become localized and black spots may appear on the obtained copy, so it is desirable that the gap be 500 μm or less.

Modified example On the other hand, in Fig. 4, the solid electrode 1'' has a volume resistivity of 1010.
This shows a modification example when using Ω-sized glass.
When glass is used, it has translucency, so a charging device that uses the light source 6 can be realized.

In this case, pressure is applied so that the metal electrode 2 is provided at a position that does not obstruct the optical path of the light source 6.

By using the above-mentioned charging device, the electric charge of the developed toner image on the charge receptor 3 is controlled by discharge, and the electric charge is removed by exposure. This improves the transfer efficiency and prevents unnecessary toner from being transferred to the back shadow area. It will be possible to prevent this from happening.

Example 2 The charging device described in Example 1 employs the solid electrode 1 made of a high electrical resistor, so that the current flowing between the solid electrode 1 and the charge receptor 30 is ineffective with a discharge current efficiency of approximately 100X. Since the current required for removing the charge is almost zero, it is necessary to supply only the current necessary for removing the charge.This allows the device itself to be made smaller, and the amount of ozone generated is also reduced, so it does not pollute the environment. This had the effect of reducing the amount of

However, if the contact between the solid electrode 1 and the metal electrode 2 that supplies current thereto is incomplete, there is a problem that the current flowing from the solid electrode 1 to the charge receptor 3 becomes non-uniform. In order to solve the above problems, good results have been obtained by bringing the solid electrode 1 and the metal electrode 2 into close contact as follows. The solid electrode 1 has a volume resistivity of 10 to 1♂Ωm as in Example 1.
A semiconductive material with a surface resistance of 106 Ω or more was used, and the solid electrode 1 was housed in a protective case 25 made of an insulator with the metal electrode 2 in close contact with the back surface of the solid electrode 1 as shown in FIG. .

Then, when the charging device having the above configuration was installed so that the solid electrode 1 faced the charge receptor 3 with a gap in between, and a DC power source 4 of -3 KV was applied to the metal electrode 2, the charge receptor 3
The surface could be charged to 1,800 μm.

Modified Example In order to further improve the adhesion between the solid electrode 1 and the metal electrode 2,
A metal electrode 2 was formed by silk screen printing a conductive paste on the back surface of the solid electrode 1, and when a DC power source 4 was applied to the metal electrode 2 as shown in FIG.
The surface of the charge receptor 30 could be charged in the same manner as in Example 2 above.

Similar results were also obtained when the metal electrode 2 was formed by vapor depositing carbon or a conductive metal instead of printing the #L metal electrode 2 on the back surface of the solid electrode 1.

Embodiment 3 FIG. 7 shows an embodiment in which multiple types of gold JA Hirogoku 21.22123 are provided on the back surface of the solid electrode 1 according to the size of the original 10 to be copied. To explain, when copying the original 10 using the charge receptor 3,
It is necessary to remove static electricity from areas other than the image area of the charge receptor 3 using an eraser, etc.
Power consumption also increases due to the eraser, etc.

Furthermore, if the static electricity is not removed using an eraser or the like, areas other than the image area are also developed, toner is wasted, and the load on the cleaning device 20 also increases.

Therefore, in this embodiment, as shown in FIG.
A plurality of metal electrodes 21122@2s, for example, three metal electrodes 21122@2s, whose lengths are set for each document size, are arranged in parallel on the back side of the document, and these metal electrodes 21y2m and 23 are connected to terminals 2a and 23, respectively.
2b and 2c are provided, and the DC power source 4 is selectively applied using the changeover switch 26 according to the document size.
It is something that Note that 27 indicates an application switch.

As a result, the metal electrode 2x to which the DC power supply 4 is applied,
22, 23 and the surface of the charge receptor 30 facing the solid electrode 1 between them, the selected metal electrode 21°2x H2:
Ions are released from the solid electrode 1 according to the length of s [,
The surface of charge receptor 3 is charged.

Further, since the metal electrodes to which the DC power source 4 is not applied are electrically floating, ions are not emitted toward the charge receptor 3 from the solid electrode 1 facing these metal electrodes.

As above 5, solid electrode IK multiple metal electrodes 21°2λ,
23, the voltage applied to each metal electrode 21, 22, 23 can be extremely low compared to a conventional charger using a discharge wire.
The interval between the solid electrodes 22 and 23 may be narrow, so that even if the solid electrode IK is provided with a plurality of metal electrodes 21, 22 and 23, the solid electrode i itself may be small, and the charging device will not become large.

In addition, the changeover switch 26
If it is configured to turn off intermittently, unnecessary charges will not be generated between each image, so it is possible to obtain the same function as an interimage lamp with metal electrodes in two directions, and an interimage lamp. can also be omitted.

Modified Example On the other hand, FIG. 9 shows a modified example of the third embodiment described above, in which a plurality of solid electrode IKs, for example, a metal electrode 2 (divided into three), is shown.

22v23 are adhered in a straight line with a conductive adhesive.

A DC power source 4 can be applied to each metal electrode 2122 2'3 according to the copy size using a changeover switch 28, 29.

For example, when copying a small-sized original, turn on only the application switch 27, and when copying a medium-sized original, turn on the application switch 27.
Turn on switch 28, and for large size switch 27,
In particular, when turning on 2g and 29, the metal electrode 2;
2; , 2 Ions are released from the solid electrode 1 according to the length of 2 toward the charge receptor I, and the surface of the charge receptor 3 becomes electrified in accordance with the copy size.

It goes without saying that the number of metal electrodes 2 is not limited to those of the above embodiments and modifications.

Example 4 FIG. 11 is an example showing a means for supporting the solid electrode 1. The solid electrode 1 is made of a conductive polymer or a conductive material made of a polymer such as a π-conjugated system, a metal chelate system, or a charge transfer complex system. Conductive polymers made by kneading them into polymers, conductive polymers made by kneading antistatic agents into polymers, conductive polymers made from composites of hydrophilic rubber and polymers, soda lime glass and borosilicate glass. It is made of glass or ceramic with additives added to which the resistance value has been adjusted, and has a volume resistivity of 10 to 1 convex i and a surface resistance of 10 6 Ω or more.

Further, the solid electrode 1 has a cross section formed into an almost inverted mountain shape, and a metal electrode 2 is closely attached to the upper surface of the base, and a DC power source 4 is applied to the metal electrode 2. The solid electrode 1 is attached to a support 30 made of an insulating material so as to face the charge receptor 3 at an air temperature of 200 μm. The mounting method is to install the insulating support 3 in advance.
0, diagonally forming recesses m30a into which both side edges of the solid electrode 10 can be inserted, and inserting the both side edges of the solid electrode 1 into these grooves 30a from the end side of the insulating support 30. , the fixed electrode 1 is fixed to the insulating support 30, and if this mounting method is used, even if the solid electrode 1 is twisted or warped, it can be inserted into the insulated support 30 to prevent the twist or warp. Since it can be corrected, the distance between the solid electrode 1 and the charge receptor 3 can be kept uniform over the entire length. Furthermore, by forming the support 3o from an insulating material, it is possible to prevent current from leaking from the solid electrode 1 to the support 3°, and therefore it is also possible to prevent the solid electrode 1 from deteriorating due to leakage.

Modified Example FIG. 12 shows a modified example of the solid electrode support means, in which the solid electrode 1 is formed into a polygonal shape, for example, a hexagonal cylinder, and the metal electrode 2 is tightly attached to the inner surface of the side facing the charge receptor 3. It is set up.

Further, the insulating support 3o that supports the solid electrode 1 has a V-shaped groove 30b into which the four corners of the solid electrode 1 fit,
These V-shaped grooves 30b are fixed to the insulating support 30 by inserting the solid electrode 1 from the end side of the K insulating support 30, and the surface facing the charge receptor 3 during use is If a problem occurs in the solid electrode 30, the solid electrode 10 can be pulled out from the insulating support 30 and reinserted so that the other side faces the charge receptor 3. Six sides can be used, which greatly extends the life of the solid electrode 10. Improvements can be made.

Embodiment 5 The embodiment shown in FIG. 13 is an embodiment in which a metal electrode 2 is embedded in a solid electrode 1. To explain this next, the solid electrode 1 is made of the same material as in the above embodiment 4, and a DC power supply is used. The surface of the metal electrode 2 to which No. 4 was applied is covered with a solid electrode 1 with a thickness of 1 mm.
Since the upper and lower surfaces of the solid electrode 1 can be used as discharge surfaces, the lower surface is first placed opposite the charge receptor 3 with a gap between them, and charged. If the lower surface becomes deteriorated or soiled, the upper surface can be used as a discharge surface by reversing the upper and lower surfaces, thus doubling the service life.

In addition, in order to support the solid electrode 1, it must be fixed i1 so as not to stain or damage the discharge surface! It is desirable that the corner of pole 1 be supported by an insulator holder.

Modified Example FIG. 14 shows a modified example in which the metal electrode 2 and the solid electrode 1 covering it are polygonal, for example, hexagonal columnar. Since there are six discharge surfaces, if the discharge surface is damaged or deteriorated. By changing the discharge surface, the life span can be significantly improved.

Embodiment 6 FIG. 15 shows another embodiment in which the hexagonal columnar solid electrode 1 and metal electrode 2 described in the modification of Embodiment 5 are elastically supported by a biasing means 34 such as a spring through a support 33. This is an example, in which a shaft portion 2a protruding from both ends of the metal electrode 2 is rotatably supported by a support 33 having a rectangular cross section, and a solid electrode 1 is attached to the tip of the shaft portion 2a. A roller 36 is rotatably supported via a bearing 37 in circumferential contact with the charge receptor 3 facing the charge receptor 3 to maintain a constant gap between the solid electrode 1 and the charge receptor 3, for example, 200 μm.

Further, the support body 33 that supports the solid electrode 1 and the metal electrode 2 is made of an insulator, and is biased toward the charge receptor 3 by a biasing means 34 provided at the back, thereby causing the roller 36 to maintain a certain level. It is brought into contact with the surface of the charge receptor 3 by pressure.

In the charging device configured as 5 above, the discharge surface of the solid electrode 1 can be brought close to the charge receptor 3 by reducing the diameter of the roller 36, and the distance between the two can be easily and reliably set. .

Even if the charge receptor 3 is eccentric, the roller 36 rotating in contact with the surface of the charge receptor 3 maintains a gap between the solid electrode 1 and the charge receptor 30, so there is no risk of the two coming into contact.

Example 7 Figure 17 shows an example in which the discharge performance was prevented from deteriorating due to foreign matter such as hetoner adhering to the solid electrode 1. Gold Ml! The DC power source 4 and the AC power source 39 can be selectively applied to the pole 2Vc by a changeover switch 38.

That is, as the number of copying cycles increases, the discharge surface of the solid electrode 1 facing the charge receptor 3 becomes contaminated with foreign matter such as toner, and the discharge performance deteriorates.

Therefore, during the copying cycle, a voltage of -3KV was applied to the metal electrode 2 by the direct i power supply 4, but during cycles other than the copying cycle, a voltage of 2KV, +000 Hz was applied by the AC power supply 39.
A high-frequency alternating electric field was formed around the solid electrode 10 by applying an alternating current voltage of .

As a result, the foreign matter attached to the solid electrode IK is scattered toward the charge receptor 3, so that the discharge surface of the solid electrode 1 can always be maintained in a clean state. Furthermore, the reason why foreign matter adhering to the solid electrode 1 can be removed by applying the AC power supply 39 to the metal electrode 2 is that when the toner used is The toner then flies towards the charge receptor 3 and returns to the solid electrode 1 side again in a negative half cycle, but at this time it collides with the remaining toner adhering to the solid electrode 1.
The remaining toner floats up and flies to the charge receptor 3 again in the next ten half cycles.

While repeating the above operation, most of the toner attached to the solid electrode 1 is adsorbed to the charge receptor 3 side, and is removed by the cleaning device f20 (see Figure 2) that cleans the surface of the charge receptor 3. Be it.

Modification Example In the above embodiment, the metal electrode 2 is used to charge the charge receptor 3.
I applied a DC power supply 4 of -3KV to , but from +2KV to +
Even when a DC voltage of 5 KV was applied, it was found that approximately gox, which was a foreign substance attached to the solid electrode 1, moved to the charge receptor 3 side, and the cleaning effect of the solid electrode 1 was observed.

Furthermore, when an AC voltage of 2 KV and a frequency of 1000 Hz and a DC voltage of +0.5 KV were simultaneously applied to the metal electrode 2, 90 to 95 N of foreign matter attached to the surface of the solid electrode 1 moved to the charge receptor 3 side, and the solid The cleaning effect of electrode 1 was observed.

Figure 18 shows the degree of dirt removal with respect to AC and DC applied voltages.
Effects were also observed with KV, DC applied voltage +〇, and 4KV.

In addition, in this table, ◎ means the degree of dirt is good, ○ means good, and Δ
indicates somewhat good.

Moreover, FIG. 19 is a diagram showing the relationship between the frequency of applied alternating current and dirt removal efficiency.

Example 8 Figure 20 shows an example in which a ceramic layer is provided on the discharge surface of the solid electrode 1.This will be explained next.The solid electrode 1 made of a semiconductive material has a discharge surface that is exposed to plasma during discharge. When exposed, active oxygen and ions generated during discharge break the molecular bonds of the material, causing deterioration.

Therefore, if the entire solid electrode 1 is made of ceramic,
Although deterioration of the discharge surface can be prevented, if the entire long solid electrode 1 is made of ceramic, the flatness will be lost due to the heat during high temperature sintering at 1500 to 2000°C, and if the solid electrode 1 is used, it will not be possible to accept charge. The distance to the body 3 becomes uneven, making it impossible to charge the battery uniformly.

In addition, since the long solid electrode 1 made of ceramic is brittle,
There are some defects that can easily cause damage during manufacturing, cleaning, or replacement.

Therefore, in this embodiment, a solid electrode 1 made of a semiconducting material is used.
A ceramic layer 40 with a thickness of 1 μm and 8°C was formed on the discharge surface 1a by sputtering.

The chemical ranking used is silicon oxide (Sing).
), silicon nitride (5i3N4), silicon carbide, etc., and sputtering time was controlled to obtain a film thickness of 1 μm.

Note that this film thickness of 1 μm is a sufficient distance to isolate plasma from the discharge surface 1a of the solid electrode 1, but the distance is not limited to this.

A metal electrode 2 is attached to the back of the solid electrode 1 manufactured as described above, and a DC power source 4 is applied to the metal electrode 2.
The time taken until the discharge surface 1a of the fixed electrode 1 deteriorated was measured.

As a result, the surface of the solid electrode 1 without 40 ft of ceramic layer on the discharge surface 1a deteriorated in about 10 hours;
In the solid electrode 1 provided with the ceramic layer 40, no deterioration of the discharge surface 1a was observed even after 50 hours.

Modification Example 1 Aluminum oxide (ktgo) is applied to the discharge surface 1a of the solid electrode 1.
s) was reactively deposited to achieve a film thickness of 1.5 μm.
A ceramic layer 40 was formed.

Although this ceramic layer 40 was formed in an atmosphere with an oxygen pressure of 10 to 10 Torr using aluminum as an evaporation source, a similar ceramic pN40 can also be obtained by performing reactive sputtering in oxygen.

Modification 2 Plasma chemical vapor deposition (CVP) is applied to the discharge surface 1a of the solid electrode 1.
) was used to form a ceramic layer 40 made of silicon oxide (SiOa) of OoBpm. This ceramic layer 40
was formed by performing high frequency discharge in a mixed gas of 8iH4 and 6 using the solid electrode 1 as an electrode.

It was also found that by forming the ceramic layer 40 on the discharge surface 1a of the solid electrode 1, deterioration of the discharge surface 1a can be prevented by changing the method of forming the collapse.

Embodiment 9 FIGS. 21 and 22 show another embodiment in which a static elimination lamp 42 is provided behind the solid electrode 1. Next, this will be explained. (see FIG. 21) to eliminate static electricity from untransferred toner remaining on the surface of the charge receptor 3 during the transfer process.A static elimination lamp 42 is installed behind the solid electrode 1. There is a button to control the charge of residual toner.

That is, a metal electrode 2 is attached to the back surface of the solid electrode 1, and a power source 4 is connected to the solid electrode IK via this metal electrode 2.
A voltage is applied, which causes a voltage of 400 Hz, 0.3 to O-5 from the solid electrode 1 to the charge receptor 3.
AA/esx f) AC IAt Den'? tr b' irradiated and further K 0.02-0-05 lIA/cs
(1) When a positive DC charge is irradiated and the toner on the surface of the charge receptor 3 is neutralized, at the same time, the static electricity is also removed by the static elimination lamp 42.

As a result, the charge of the toner remaining on the surface of the C charge receptor 3 is eliminated by the solid electrode 1, and the charge on the surface of the charge receptor 3 other than the portion where the toner remains is eliminated by the static elimination lamp 42, so that the cleaning device 20 allows good leaning.

Further, the solid electrode 1 is made of gold FA by depositing SnO on the back surface of a semiconductive material having a translucent property and having a volume resistivity of 10 to 1 Ωm so that the light from the static elimination lamp 42 can pass therethrough.
The one with t-pole 2 is used.

Modification Example After uniformly primary charging the surface of the charge receptor 30 with the solid electrode 1, secondary charging is performed by irradiating an alternating or negative DC charge from the solid electrode 1, while charging the surface of the charge receptor 30 from behind the solid GT electrode 1. The charge receptor 3 is exposed to light, and a static 1i is applied to the surface of the charge receptor 30.
It can also be applied to a charging device that forms a Lum.

Embodiment 10 FIG. 23 shows a shield electrode 45 on the discharge surface 1a of the solid electrode 1.
In an example in which a solid electrode 1 is provided, this will be explained next.
Foreign matter such as floating toner easily adheres to the discharge surface 1a of the
Also, if it adheres, there is a problem that the discharge becomes uneven.

Therefore, in this embodiment, a pair of shield electrodes 45 are provided on the discharge surface 1a of the solid electrode 1 along the longitudinal direction of the solid electrode 1 so as to be parallel to each other with an interval therebetween. The shield electrode 45 is made of a conductor with a width of about 1 inch glued with a conductive adhesive, and the shield electrode 45 is connected to a DC power source 46.
A high voltage of -1, OKV is applied.

In addition, a high voltage of approximately -3.0 KV is applied to the metal electrode 2 attached to the back of the fixed electrode 1 by a DC power source 4.
As a result, a potential of -goo v is obtained on the surface of the charge receptor 3 facing the fixed electrode j.

When a copying cycle is executed using the above-mentioned charging device, foreign matter such as floating toner generated during the copying cycle attaches to the shield electrode 45 before attaching to the discharge surface 1a of the solid electrode 1. It was possible to prevent the particles from adhering to the discharge surface 1a.

This makes it possible to obtain good copied images without having to frequently clean the discharge surface 1a of the solid electrode 1.

Effects of the Invention The charging device of the present invention has a simple configuration, is small in size, and is robust, and when it is used for charging, spark discharge is unlikely to occur between it and the charge receptor, and the charging device has excellent discharge current efficiency. It not only provides the desired characteristics, but also has the advantage of being easy to maintain and having a long lifespan.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the basic configuration of the present invention, FIG. 2 is an explanatory diagram showing an embodiment of an electronic copying machine using the charging device of the present invention, and FIG. 3 is an explanatory diagram showing an embodiment of the invention. Explanatory diagram,
Figures 4 to 23 are explanatory diagrams showing other embodiments;
4 and 25 are explanatory diagrams of the conventional technology. 1 is a solid electrode, and 3 is a charge receptor.

Claims (1)

[Claims] 1. A charging device comprising a solid electrode made of a high electrical resistance material having a volume resistivity of 10^6 to 10^1^3 Ωcm, and a voltage application electrode formed on one side thereof. . 2. The charging device according to claim 1, wherein a voltage applying electrode provided on the back surface of the solid electrode 1 is fixed to the solid electrode 1 with a conductive adhesive. 3. The charging device according to claim 1, wherein a plurality of voltage applying means are provided on the back surface of the solid electrode 1 for each copy size. 4. The charging device according to claim 1, wherein the solid electrode 1 has a polygonal shape having a plurality of discharge surfaces. 5. The charging device according to claim 1, wherein foreign matter adhering to the discharge surface of the solid electrode 1 is scattered and removed by applying AC power to the solid electrode 1 via the voltage application electrode. 6. The charging device according to claim 1, wherein a ceramic layer is formed on the discharge surface of the solid electrode 1. 7. The charging device according to claim 1, wherein the solid electrode 1 is made of a transparent material.