JP3074095B2 - Corona discharge device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corona discharge device for uniformly charging an object to be charged by utilizing a corona discharge phenomenon.
More specifically, by using a corona discharge device having a plurality of discharge members and a resistor connected to each of the discharge members and a voltage source connected to the resistors, a stable discharge with a smaller discharge current is achieved. The present invention relates to a corona discharge device capable of generating a small amount of ozone and capable of performing uniform charging.

[0002]

2. Description of the Related Art In an image forming apparatus for forming an image by an electrophotographic method, a high voltage of 5 to 10 kv is applied to a tungsten wire having a diameter of 50 to 100 μm as a charging device for supplying a predetermined charging potential to the surface of an image forming body. There is known a corona discharge device that applies an electric charge to move the ions generated by the discharge on the wire to the surface of the image forming body to perform charging. When this method is used for negative discharge, the discharge points are randomly located on the wire depending on the state of the wire surface, resulting in unstable and non-uniform discharge to the charged surface, so that the charged surface is uniformly charged. For this purpose, a shield case as an auxiliary electrode and a grid for potential control are used. However, this method requires a large amount of discharge current to stabilize the discharge and make the charge uniform, resulting in a large amount of ozone, resulting in deterioration of image quality and adverse effects on the human body. is there.

In recent years, for example, Japanese Patent Application Laid-Open No. 63-1527
As disclosed in Japanese Unexamined Patent Publication No. 2 (Kokai) No. 2, a corona discharge device using a sawtooth-shaped discharge electrode instead of a tungsten wire has been proposed. This type of corona discharge device has a more uniform discharge to the surface to be charged because the discharge points are regularly located at the tip of the sawtooth, and has significant structural and operational advantages over the wire type. In addition, the discharge current required for uniform charging is small, the structural strength is relatively high, and the amount of undesired ozone is small.
However, on the other hand, there are drawbacks in that the means for supporting the saw-tooth electrode becomes complicated, and the tips of the saw-tooth electrode are easily damaged. Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 63-167382, a system in which a discharge resistor and a discharge electrode are formed on an insulating corona-resistant substrate has been proposed. In this method, the discharge electrode and the like are fixed on an insulating substrate, so that the discharge electrode can be easily mounted in the corona discharge device. There is an advantage that it is protected by the substrate and hardly damaged.

FIG. 13 is a structural view of a conventional corona discharge electrode, in which 51 is a sawtooth discharge electrode, 52 is an insulating substrate,
53 is a counter electrode and 54 is a high voltage power supply. Insulating substrate 5
A saw-tooth discharge electrode 51 made of stainless steel is provided on 2. The number of teeth of the sawtooth discharge electrode 51 is 10, and the pitch between each tooth is 2 mm. A counter electrode 53 made of stainless steel is fixed opposite to the sawtooth discharge electrode 51 at a predetermined interval g from the tip of the sawtooth discharge electrode 51.
A high voltage power supply 54 is connected to the sawtooth discharge electrode 51, and a corona discharge is generated in the counter electrode 53 by applying a high voltage to the sawtooth discharge electrode 51.

The discharge current flowing through each electrode during the corona discharge was measured by an ammeter connected in series between the sawtooth discharge electrode 51 and the high voltage power supply 54. FIG. 14 shows the applied voltage −
The discharge current of each electrode at 4.3 kv and g = 7 mm is shown. Thus, although discharge occurs at substantially equal intervals, the amount of discharge (discharge current) varies greatly and fluctuates, resulting in unstable discharge. One of the solutions to this problem
First, it is known that the current flowing through each of the electrode members is stabilized by connecting each of the electrode members to a power supply via a separate resistor. In order to solve this problem, for example, Japanese Patent Publication No. Hei 3-1663 has been proposed.

[0006]

As described above, in the conventional corona discharge device, since the discharge point is specified, damage to the tooth tip of the saw-tooth electrode, adhesion of suspended matter to the tip of the electrode,
The electrode is susceptible to the influence of the tilt and the like, and the discharge is unstable, but it is unstable. To stabilize the discharge, a discharge current several times to several tens times the actual charge amount must be applied. However, even if there is an electrode with insufficient resistance, the pitch of the tooth tip must be reduced to some extent so as not to cause charging failure, and as a result, there is a problem similar to the wire method in which a large amount of ozone is generated. Also, in order to form a discharge electrode and a discharge resistor on a ceramic substrate, a thick film printed circuit technique such as firing the electrode pattern and the resistor after printing the thick film is used. turn into. Also, the need to utilize a large number of resistors complicates the corona discharge device, not only significantly increasing the material costs, but also making it difficult to manufacture. As disclosed in the aforementioned Japanese Patent Publication No. 3-1663, it has been proposed to simplify the device by providing a space instead of via a resistor and utilizing a voltage drop due to discharge in the space. However, the discharge in space is unstable and easily affected by the environment. The publication is not intended to reduce the generation of ozone by reducing the discharge current, but to utilize discharge, and is not suitable as a technique for achieving the object of the present invention. .

The present invention has been made in view of the above circumstances, and it is possible to generate a stable discharge with a smaller discharge current, generate less ozone, and perform uniform power storage. It is an object of the present invention to provide a corona discharge device capable of easily assembling a corona discharge device.

[0008]

According to the present invention, in order to achieve the above object, the invention according to claim 1 comprises a plurality of discharge members comprising saw-tooth, comb-like or multi-needle electrodes; It has a plurality of resistors respectively connected to the member and a voltage source connected to the resistors, and a potential drop in the resistors is 200 V or more. Further, the invention according to claim 2 is characterized in that the discharge members are opposed to the counter electrode with a space of 7 mm, and the discharge members are arranged with a space of 2 mm. The invention according to claim 3 provides a plurality of discharge members formed of saw-tooth, comb-like or multi-needle electrodes, and a common discharge member for the plurality of discharge members.
A connected resistor and a common electrode connected to the resistor
And a voltage source connected to the common electrode.
The resistance value between the discharge members, between the discharge member and the common electrode
It is characterized in that it is made larger than the resistance value . Further, the invention according to claim 4 is characterized in that it has a plurality of discharge electrodes each having a cut-out portion for press-contact and a resistor pressed against the cut-out portion of the discharge member.

[0009]

The discharge member includes a plurality of discharge members formed of sawtooth, comb, or multi-needle electrodes, a plurality of resistors respectively connected to the discharge members, and a voltage source connected to the resistors. Since the potential drop at the resistor is 200 V or more, the discharge at each discharge member can be stabilized and uniformized, and uniform charging can be performed with a smaller discharge current. Also, serrated,
A plurality of discharge members consisting of comb-like or multi-needle electrodes,
A resistor commonly connected to the plurality of discharge members;
A common electrode connected to the antibody, and connected to the common electrode
A voltage source, and a resistance value between the adjacent discharge members,
By increasing the resistance value between the discharge member and the common electrode , the discharge in each discharge member can be stabilized and uniformized without inviting a complicated device, a high material cost, and a difficult manufacturing method. Uniform charging can be performed with a small discharge current, and as a result, generation of ozone can be reduced. In addition, since a plurality of discharge electrodes each having a cut-out portion for pressure contact and a resistor that presses one end to the cut-out portion of each discharge electrode is provided, the resistor is pressed into the cut-out portion to be electrically operated. Connection is obtained and the assemblability is excellent.

[0010]

Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a corona discharge device according to the present invention. In the drawing, 1 is a sawtooth discharge electrode, 2 is an insulating substrate, 3 is a counter electrode, 4 is a high voltage electrode,
Is a resistor. A sawtooth discharge electrode 1 made of stainless steel is provided on an insulating substrate 2. The saw-tooth discharge electrode 1 has 10 teeth and the pitch between each tooth is 2 mm. A counter electrode 3 made of stainless steel is opposed to the saw-tooth discharge electrode 1 at a predetermined interval g from the tip of the saw-tooth discharge electrode 1.
Has been fixed. A high voltage power supply 4 is connected to the sawtooth discharge electrode 1, and a corona discharge is generated in the counter electrode 3 by applying a high voltage to the sawtooth discharge electrode 1. The discharge current flowing through each electrode during this corona discharge was measured by an ammeter connected in series between the sawtooth discharge electrode 1 and the high-voltage power supply 4. Each discharge electrode is connected to a high voltage power supply 4 via a resistor 5 of 500 MΩ. FIG. 2 shows the discharge current of each electrode when discharging at an applied voltage of -4.78 kv and an interval g of 7 mm. Thus, the discharge amount at each electrode was very stable, and good discharge characteristics were obtained.

FIG. 3 is a block diagram of an electrophotographic apparatus such as a copying machine or a laser printer using the corona discharge device according to the present invention. In FIG. 3, reference numeral 6 denotes an image forming body (photoreceptor); Is a developing device, 9 is a transfer material, 10 is a fixing device, 11 is a cleaner, 12 is a discharge lamp, 13 is a corona discharge device (charger), 13a is a sawtooth discharge electrode, 13b is an insulating substrate, and 13c is a chip resistor. , 13d is a shield case, 1
3e is a grid electrode, 13f and 13g are high voltage power supplies, 14
Is a corona discharge device (transfer device), 14a is a sawtooth discharge electrode, 14b is an insulating substrate, 14c is a chip resistor, 14d
Is a shield case, and 14e is a high voltage power supply.

The photoreceptor 6 has a drum-shaped base made of a conductive material such as aluminum and is rotatably supported on the drum, and has an OPC (Organic) on the peripheral surface of the base.
Photoconductor) and the like. The photoconductor 6 is configured to be driven to rotate in the direction of the arrow A shown in the figure, and the photoconductor 6 has a corona discharge device (charger) 13 and a corona discharge device (transfer device) 1.
4 are in close proximity. The charger 13 includes an insulating substrate 13
A saw-toothed discharge electrode 13a made of stainless steel (0.1 mm in thickness) is disposed on b, and is supported in a shield case 13d having a U-shaped cross section. The insulating substrate 13b is provided with a common electrode, and is connected to the sawtooth discharge electrode 13a via a chip resistor 13c.

FIG. 4 is an enlarged view of a main part of the sawtooth discharge electrode in FIG. 3. In FIG. 4, reference numeral 13h denotes a common electrode, and other portions having the same functions as those in FIG. The number of teeth of the discharge electrode 13a is 52, the pitch p between the teeth is 4 mm, and the tip of the discharge electrode 13a is positioned so that the tip protrudes from the edge of the insulating substrate 13b toward the photoconductor 6 (d = 2 mm). It is adhered on the insulating substrate 13b. Common electrode 13h
Is connected to the high-voltage power supply 13f.
, A corona discharge is generated from the tooth tip, and the surface of the photoconductor 6 is charged. Discharge electrode 13
a between the photoconductor 6 and the photosensitive member 6 by a high-voltage power supply 13g.
A grid electrode 13e to which a voltage is applied to V is provided, and control is performed so that the charged potential of the photoconductor 6 becomes a predetermined potential (−700 V). After the surface of the photoconductor 6 is charged to a predetermined potential by the charger 13, an electrostatic latent image is formed on the surface of the photoconductor 6 by exposure 7, and the electrostatic latent image is developed by the developing device 8.

Next, when the toner image reaches a transfer portion where the corona discharge device (transfer device) 14 and the photosensitive member 6 face each other, the transfer material 9 is supplied to the transfer portion in time therewith (see FIG. 1). Arrow B direction). A transfer unit 1 similar to the charger 13 except that there is no grid electrode at the transfer site
By 4, the back surface of the transfer material 9 is charged, and the toner image on the photoconductor is transferred to the transfer material 9. Thereafter, the transfer material 9 carrying the toner image is conveyed to the fixing device 10, and the toner remaining on the photoreceptor 6 is collected by the cleaner 11. Enter the next step.

In the experimental apparatus shown in FIG.
Normalized standard of potential drop and discharge current at each pin resistor when 50M, 100M, 500M, 1G, 5GΩ and discharge current are changed to about 0.1, 0.5, 1.0μA per pin The relationship between the deviations is shown in FIG. Thus, when the potential drop across the resistor becomes 200 V or more, the variation in the discharge current is reduced, and the discharge is stabilized. The potential drop across the resistor to reduce the variation in the discharge current depends on the variation in the discharge conditions such as the state of the electrodes and the environment, but the results of this experiment were accurately produced by etching and have no history. In consideration of electrode deterioration, damage, adhesion of foreign matter, environmental change, and the like due to long-term use, it is possible to absorb the variation in the discharge conditions if there is a potential drop of about 500 V. And a stable discharge is obtained.

FIGS. 6A to 6C show the surface potential of the photoconductor when the high-voltage power supply 13f is adjusted so that the total discharge current becomes 30 μA and the photoconductor 6 is charged.
A saw-tooth discharge electrode (102 teeth) without a resistor; FIG. 12B shows a saw-tooth discharge electrode (52 teeth) in which each saw-tooth discharge electrode is connected to a high voltage power supply 13f via a 300 MΩ resistor. ), And FIG. (C) shows the result of the same 500 MΩ. The process speed is 30 mm /
s, the charging width is 210 mm. In FIG. 8C, the potential ripple was about 20 V, and good chargeability was obtained.

FIGS. 7 (a) to 7 (d) are structural views for explaining another embodiment of a corona discharge device according to the present invention, wherein FIG. 7 (a) is a sawtooth discharge electrode, and FIG. FIG. 3C shows a state in which the sawtooth discharge electrode and the common electrode are mounted on an insulating substrate, and FIG. 4D shows a state in which the common support portion of the sawtooth discharge electrode in FIG. FIG. In the figure, 21 is a sawtooth discharge electrode, 21a is a press-fitting slit groove, 21b is a half-etched portion, 21c is a common support portion, 22 is a common electrode, 22a is a slit groove, and 23 is an insulating substrate.

A 0.1t stainless steel plate is photo-etched to form a sawtooth discharge electrode 21, and a slit groove 21a for press-fitting a resistor is provided at the center of the discharge electrode 21. The rear ends of the plurality of discharge electrodes are integrally supported by a common support portion 21c provided for improving the assembling workability. Further, the slit portion is subjected to half etching 21b for cutting and separating. A slit groove 22a for press-fitting the resistor also into the common electrode 22
Is provided. The common electrode 22 may use the common support portion 21c remaining after the discharge electrode 21 is cut by the half etching 21b. The discharge electrode 21 and the common electrode 22 are fixed and supported on an insulating substrate 23 made of a plastic resin or the like by adhesion, injection molding, fusion, or the like. By removing the support portion 21c, a plurality of discharge electrodes 21 that are each independently separated are formed.

FIG. 8 is an enlarged view of a main part of the sawtooth discharge electrode in FIG. 7. In FIG. 8, reference numeral 24 denotes a resistor, and other parts having the same functions as those in FIG. 7 are denoted by the same reference numerals. The number of teeth of the sawtooth discharge electrode 21 is 104 and the pitch p between each tooth is 2
mm, and is adhered onto the insulating base material 23 such that the tooth tip is located at a position protruding (d = 2 mm) from the insulating edge portion toward the photoconductor. The resistor 24 is made of an organic material such as polyethylene, polyester, polyurethane, nylon, polyamide, or polyimide, and is made of carbon black or metal powder, and is made of an inorganic material or a zinc oxide, ruthenium oxide, or the like that forms a low-cost resistor. Metal oxides that form high-resistance resistors with stable performance against temperature and humidity changes, or uniform resistors with small local resistance changes, such as halogen oxyacid salts, perhalogen oxyacid salts, and lithium perchlorate Additives such as alkali metal salts exhibiting ionic conductivity to be formed are kneaded to obtain a predetermined electric resistance. As the resistance value,
Several hundred volts with a resistor for stabilizing the discharge characteristics
It is desirable that the resistance value is about 100 MΩ or more so as to cause the voltage drop.

The resistor 24 made of an organic material has one end press-fitted into the slit groove 21a of the discharge electrode 21 and the other end pressed into the slit groove 22a of the common electrode 22. Electrical connections are made as shown in the electrical connection explanatory diagram. When the resistors 24 are press-fitted, the required number of resistors may be collectively press-fitted to shorten the assembly time. After press-fitting the resistor, if necessary, the resistor 24 and the periphery of the slit grooves 21a and 22a may be resin-molded to prevent moisture.

FIG. 10 is a block diagram of an electrophotographic apparatus such as a copying machine or a laser printer using the corona discharge electrode shown in FIG. 7, in which 21 and 21a are sawtooth discharge electrodes, and 22 and 2 are shown.
2a is a common electrode, 23 and 23a are insulating substrates, 24 and
24a is a resistor, 25 and 25a are shield cases, 26
Is a grid electrode, 27a to 27c are high voltage power supplies, and other parts having the same function as in FIG. 3 are denoted by the same reference numerals. The photoreceptor 6 has a drum-shaped base made of a conductive material such as aluminum and is rotatably supported on the drum, and a photoconductive layer made of OPC or the like is formed on the peripheral surface of the base. It was done. The photoreceptor 6 is configured to be driven to rotate in the direction of arrow A shown in the figure, and a corona discharge device (charging device) 13 and a corona discharge device (transfer device) 14 are closely opposed to the photoreceptor 6. . The charger 13 has a sawtooth discharge electrode 21 made of stainless steel (0.1 mm in thickness) disposed on an insulating upper substrate 33 and is supported in a shield case 25 having a U-shaped cross section. The insulating base material 3
3 is provided with a common electrode 22 and is connected to the sawtooth discharge electrode 21 via a resistor 24, respectively.

The common electrode 22 is connected to a high-voltage power supply 27a. When a high voltage is applied by the high-voltage power supply 27a, a corona discharge is generated from the tooth tip to charge the surface of the photoreceptor 6. A grid electrode 26 to which a voltage of about -720 V is applied by a high-voltage power supply is disposed between the discharge electrode 21 and the photoconductor 6, so that the charging potential of the photoconductor 6 becomes a predetermined potential (-700V). Control. After the surface of the photoconductor 6 is charged to a predetermined potential by the charger 13, an electrostatic latent image is formed on the surface of the photoconductor 6 by exposure 7, and the electrostatic latent image is developed by the developing device 8. Next, when the toner image reaches a transfer portion where the corona discharge device (transfer device) 14 and the photoreceptor 6 face each other, the transfer material 9 is supplied to the transfer portion in synchronization with the timing (in the direction of arrow B in the drawing). At the transfer portion, the back surface of the transfer material 9 is charged by a transfer device 14 substantially similar to the charger 13 except that there is no grid electrode, and the toner image on the photoconductor is transferred to the transfer material 9. Thereafter, the transfer device 9 carrying the toner image is transported to the fixing device 10, and the toner remaining on the photoconductor 6 is collected by the cleaner 11.
The remaining residual charges are removed by the charge removing lamp 12 and the next step is started.

FIG. 11 is a block diagram for explaining still another embodiment of the corona discharge device according to the present invention.
Is a sawtooth discharge electrode, 32 is an insulating substrate, 33 is a counter electrode, 34 is a common electrode, 35 is a resistor, and 36 is a high voltage power supply. A sawtooth discharge electrode 31 is connected via a resistor 35 on an insulating substrate 32 provided with a common electrode 34. Other operations are the same as those in FIG. Also,
The discharge characteristics are the same as in FIG. Further, it is needless to say that an electrophotographic apparatus such as a copying machine or a laser printer as shown in FIG. 3 can be constituted by using the corona discharge device shown in FIG.

FIGS. 12A to 12C are diagrams showing the configuration of the discharge electrode portion at the time of assembling, and reference numerals in the drawing are the same as those in FIG. After superimposing the resistor 35 on the insulating substrate 32 and superimposing the sawtooth discharge electrode 31 formed by etching, laser processing or the like on the resistor 35, the sawtooth discharge electrode 31 is formed. Pressure bonding or thermocompression bonding from above. Insulating substrate 32, resistor 35 and discharge electrode 31
After being firmly pressed, they are cut off at the half-etched or half-laser processed folds. In this state,
The resistance value between adjacent discharge electrodes is 1 * 10 ¹² when 100 V is applied.
Ω or more, and the resistance between the discharge electrode and the common electrode is about 1 * 10 ⁹ Ω when 500 V is applied. Common electrode 34
Is connected to a high-voltage power supply 36, and by applying a high voltage from the high-voltage power supply 36, a corona discharge is generated from the tooth tip and the surface of the photoconductor 6 is charged.

In FIG. 11, the resistance of the resistor 34 is set to 10M, 50M, 100M, 500M, 1G, 5G.
Ω and discharge current of about 0.1, 0.3, 0.3 per pin.
The relationship between the potential drop at the resistor at each pin and the normalized standard deviation of the discharge current at pin 10 when the values are changed to 5, 0.7, 1.0, and 5.0 μA is shown in FIG. Was. Thus, when the potential drop in the resistor becomes 200 V or more, the variation in the discharge current is reduced and the discharge is stabilized. In another embodiment, a conductive substrate may be used instead of the insulating substrate 32. In this case, it is not necessary to attach the common electrode 34, and a high voltage power supply 36 is connected to the conductive substrate to apply a high voltage. Although the saw-tooth discharge electrode has been described in the present embodiment, it goes without saying that the same effect can be obtained with a comb-like or multi-needle electrode. In the present embodiment, the charging device of the electrophotographic apparatus has been particularly described. However, the present invention is not limited to this. For example, the present invention is applicable to a corona discharge device such as a transfer device, a static elimination device, and a peeling device of an electrophotographic device. It goes without saying that also applies.

[0026]

As is apparent from the above description, the present invention has the following effects. (1) It has a plurality of discharge members formed of sawtooth, comb or multi-needle electrodes, a plurality of resistors respectively connected to the discharge members, and a voltage source connected to the resistors, By using a corona discharge device in which the potential drop at the resistor is 200 V or more, a stable discharge can be generated with a smaller discharge current, and the generation of ozone is small,
Uniform charging can be performed. (2) A plurality of discharge members formed of saw-tooth, comb-like or multi-needle electrodes and commonly connected to the plurality of discharge members
A resistor, a common electrode connected to the resistor, and the common electrode.
A voltage source connected to a pole, and between adjacent discharge members.
Is greater than the resistance between the discharge member and the common electrode.
The stabilization and uniformity of the discharge at each discharge member without incurring complicated equipment, increasing the cost of materials, and difficult manufacturing methods by making the device sharper, assures uniform charging with less discharge current. Ozone generation can be reduced. (3) In a corona discharge device using a sawtooth discharge electrode, a resistor for stabilizing discharge is press-fitted and connected to an electrode slit to provide a corona discharge device that can be assembled extremely easily. The resistor to be press-fitted is also very inexpensive, mainly made of an organic material, to reduce the cost of the apparatus.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a corona discharge device according to the present invention.

FIG. 2 is a diagram showing discharge characteristics of a sawtooth discharge electrode in FIG.

FIG. 3 is a configuration diagram of an electrophotographic apparatus using the corona discharge device according to the present invention.

FIG. 4 is an enlarged view of a main part of the sawtooth discharge electrode in FIG. 3;

FIG. 5 is a diagram showing a relationship between a potential drop in a resistor according to the present invention and a normalized standard deviation of a discharge current.

FIG. 6 is a diagram showing a surface potential of a photoconductor according to the present invention.

FIG. 7 is a configuration diagram for explaining another embodiment of a corona discharge device according to the present invention.

FIG. 8 is an enlarged view of a main part of the sawtooth discharge electrode in FIG. 7;

FIG. 9 is an electrical connection diagram of each component shown in FIG. 7;

10 is a configuration diagram of an electrophotographic apparatus using a corona discharge device using the corona discharge electrode shown in FIG.

FIG. 11 is a configuration diagram for explaining still another embodiment of a corona discharge device according to the present invention.

FIG. 12 is a configuration diagram of a discharge electrode portion of the corona discharge device according to the present invention at the time of assembly.

FIG. 13 is a configuration diagram of a conventional corona discharge electrode.

FIG. 14 is a diagram showing discharge characteristics of the sawtooth discharge electrode in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Serrated discharge electrode, 2 ... Insulating substrate, 3 ... Counter electrode,
4 high voltage electrode, 5 resistor, 6 image forming body (photoreceptor), 7 exposure direction, 8 developing device, 9 transfer machine, 10
Fixing device, 11 Cleaner, 12 Static elimination lamp, 13 Corona discharge device (charger), 13a Serrated discharge electrode, 1
3b: insulating substrate, 13c: chip resistor, 13d: shield case, 13e: grid electrode, 13f, 13g ...
High voltage power supply, 14 ... Corona discharge device (transfer device), 14a ...
Serrated discharge electrodes, 14b: insulating substrate, 14c: chip resistor, 14d: shield case, 14e: high-voltage power supply.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Sawai 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Hiroshi Ishii 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (56) References JP-A-5-2314 (JP, A) JP-A-61-110176 (JP, A) JP-A-61-244263 (JP, A) JP-A-63-221365 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/02 H01T 19/00

Claims (4)

(57) [Claims] A plurality of discharge members each having a saw-tooth, comb-like or multi-needle electrode, a plurality of resistors respectively connected to the discharge members, and a voltage source connected to the resistors. And a potential drop at the resistor is 200 V or more. 2. The discharge member is opposed to a counter electrode at an interval of 7 mm, and the interval between the discharge members is 2 m.
2. The corona discharge device according to claim 1, wherein the corona discharge device is arranged at a distance of m. 3. A plurality of discharge members comprising sawtooth, comb or multi-needle electrodes, and a plurality of discharge members in common with the plurality of discharge members.
A connected resistor, a common electrode connected to the resistor,
And a voltage source connected to the common electrode.
The resistance value between the electrical members is determined by the resistance between the discharge member and the common electrode.
A corona discharge device characterized by having a value larger than the value . 4. A corona discharge device comprising: a plurality of discharge electrodes each having a cutout portion for pressure contact; and a resistor pressed against the cutout portion of the discharge member .