JPH08137190A - Electrostatic charging device - Google Patents

Abstract

PURPOSE: To provide an electrostatic charging device with which good uniform electrostatic charging performance and high operation reliability are assured and a cost reduction and long-term maintenance of stability are attained. CONSTITUTION: A conductive fibrous member 22 is stuck to an electrostatic charging blade base material 21 and a grid-like conductive elastic member 23 inclined in the moving direction of a member 9 to be electrostatically charged is stuck to this fibrous member 22, by which an electrostatic charging blade 2 is formed. This electrostatic charging blade 2 is supported by a supporting member 3 which comes into contact with the conductive fibrous member 22 and the conductive elastic member 23 and has an electrode 31 connected to a power source 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for charging a charging member by bringing it into contact with a member to be charged.

[0002]

2. Description of the Related Art A member to be charged in an image forming apparatus such as a copying machine, a laser printer, and an image recording device is an image carrier such as a photoconductor or a dielectric, and the surface of the image carrier must be uniformly charged. No. As a charging device for performing such charging, a corona discharger is widely known.

[0003] However, in charging by a corona discharger, a high voltage power supply having an absolute value of output of 4 to 7 KV is required, so that a shielded space is required, and further, distinction and caution in wiring connection are required. . Further, in corona discharge, a large amount of corona products such as ozone is generated, and a special technique is required to cope with such corona products. As a result, the manufacturing cost of the device becomes high, and the device itself becomes large.

Therefore, in recent years, contact charging type charging devices such as brush charging, roller charging and blade charging have been devised. These devices contact a charging member, to which a power output is connected, on the surface of an image carrier as a member to be charged, and charge the charging member to a predetermined potential.
It is intended to solve the problems of the corona discharge type charging device described above.

[0005]

However, the above-described brush charging, roller charging, and blade charging devices have the following problems. In the charging device by brush charging, the brush density condition, the applied power condition, the setting condition of how to make contact with the body to be charged, and the uniformity condition of the brush manufacturing and brush mounting are practically
There were many difficult conditions, and it was very difficult to achieve uniform charging. Further, there are many problems in terms of operation reliability, such as poor electrification due to the brush hair coming off and contamination of the brush by the developer or paper dust in the apparatus, and generating noise. Was.

On the other hand, a charging device using roller charging relatively easily performs uniform production of a roller and uniform contact with an object to be charged, so that there are few problems with uniformity and operation reliability of brush charging. However, once the roller surface is scratched or the developer or paper dust inside the device adheres to the roller, the charging performance of that part differs from the charging performance of other parts, causing periodic development deterioration. Will end up. In addition, it is doubtful that the charging device using the roller charging can secure uniform charging performance in anticipation of higher density and higher speed of images expected in the future.

On the other hand, in a charging device using blade charging,
Since the portion in contact with the member to be charged is always the same linear portion at the tip or antinode of the charging blade, the state of the linear contact portion greatly affects the charging performance.
Therefore, in particular, the uniformity of mechanical precision, electrical resistance, surface state, and the like in the portion in contact with the body to be charged and the mounting uniformity of the charging blade are strongly demanded, and the manufacturing cost is inevitably increased. there were.

Further, for example, when a pinhole is formed on an image carrier such as a photoconductor, the resistance of the portion becomes lower than that of the surface of the other photoconductor. Spark discharge occurs through the pinhole portion. For this reason, there is also a problem that charges are not applied over the front surface in the longitudinal direction including the pinhole of the photoconductor, and the output image is disturbed.

On the other hand, a charging device described in Japanese Patent Application Laid-Open No. 4-350678 has been devised. This charging device has a structure in which a back electrode layer is provided on the surface of a charging blade that does not come into contact with a member to be charged, and the charging blade is sandwiched between conductive support members so that the charging blade is stably supported for a long time. .

However, also in this charging device, the linear contact portion of the charging blade in contact with the member to be charged still has
It is easy to be damaged, and the developer and paper powder are apt to be mixed and adhered to this portion. Further, there is a problem of cost increase accompanying manufacturing, processing, and mounting, and a problem that it is difficult to maintain long-term stable performance.

The present invention has been made in view of the above problems, and it is possible to secure good uniform charging performance and high operation reliability, and further to reduce cost and maintain long-term stable performance. For the purpose of providing.

[0012]

In order to achieve the above object, the invention according to claim 1 provides a charging device for charging a charged body by bringing a charging member connected to a power source into contact with the charged body. The charging member is configured to include a conductive fibrous member and a conductive elastic member, which are arranged so as to be alternately exposed on the surface side in contact with the body to be charged.

According to a second aspect of the present invention, in the charging device according to the first aspect, when the conductive fibrous member comes into contact with the charged body when the conductive elastic member comes into contact with the charged body. The configuration is such that they are arranged to face each other with a gap.

According to a third aspect of the present invention, in the charging device according to the first or second aspect, the conductive elastic member is laminated on a surface of the conductive fibrous member and has a plurality of openings. Was adopted.

According to a fourth aspect of the present invention, in the charging device according to the first or second aspect, the plurality of belt-like members are formed by laminating the conductive elastic member on the surface of the conductive fibrous member at predetermined intervals. Was adopted.

According to a fifth aspect of the present invention, in the charging device according to any one of the first to fourth aspects, the gap is 0.1 mm to 3.0 mm.

According to a sixth aspect of the present invention, in the charging device according to any one of the first to fifth aspects, the electric resistance of the conductive fibrous member and the electric resistance of the conductive elastic member are set to 10 ^1. The configuration is set in the range of 10 to 10 ¹⁰ Ωcm.

According to a seventh aspect of the present invention, in the charging device according to the sixth aspect, the electric resistance value of the conductive fibrous member is different from the electric resistance value of the conductive elastic member.

According to an eighth aspect of the present invention, in the charging device according to any one of the first to seventh aspects, a first power supply is connected to the conductive fibrous member, and a second power supply is connected to the conductive elastic member.
Power supply is connected.

According to a ninth aspect of the present invention, in the charging device according to any one of the first to eighth aspects, the voltage of the power supply is a DC voltage on which an AC voltage is superimposed.

According to a tenth aspect of the present invention, in the charging device according to any one of the first to ninth aspects, the charging member is formed in a blade shape.

[0022]

According to the charging device of the first aspect of the present invention, the conductive member and the conductive elastic member are arranged such that the charging member is alternately exposed on the surface side in contact with the member to be charged. Since, the electrification by the conductive fibrous member,
The member to be charged is charged by a two-stage charging process including charging by the conductive elastic member.

According to the charging device of the second aspect of the present invention,
Since the conductive fibrous member is arranged so as to face the charged body with a predetermined gap when the conductive elastic member and the charged body contact each other, the fiber of the conductive fibrous member by the charged body No dirt or disorder in the condition occurs. In addition, even if a part of the conductive elastic member is damaged or the like, the conductive fibrous member ensures the charging property.

According to the charging device of the third aspect of the present invention,
Since the conductive elastic member is laminated on the surface of the conductive fibrous member and has a plurality of openings, discharge is performed from the conductive fibrous member to the member to be charged through the openings.

According to the charging device of the fourth aspect,
Since the conductive elastic member is a plurality of belts laminated at predetermined intervals on the surface of the conductive fibrous member, discharge is performed from the conductive fibrous member to the charged member via the gap between the belts. .

According to the charging device of the fifth aspect,
The gap between the conductive fibrous member and the member to be charged is 0.1 m
Since the distance is set to m to 3.0 mm, the charging performance is maintained without the conductive fibrous member coming into contact with the member to be charged.

According to the charging device of the present invention, the electric resistance of the conductive fibrous member and the electric resistance of the conductive elastic member are set in the range of 10 ¹ to 10 ¹⁰ Ωcm. Therefore, desired charging performance can be obtained without applying a high voltage to the conductive fibrous member or the conductive elastic member.

According to the charging device of the eighth aspect,
Since the first power supply is connected to the conductive fibrous member and the second power supply is connected to the conductive elastic member, the voltage applied to the conductive fibrous member and the voltage applied to the conductive elastic member are changed and controlled. can do.

According to the charging device of the ninth aspect,
Since the voltage of the power supply is a DC voltage on which an AC voltage is superimposed, the charging / reverse charging process is repeated in the charging process of the charging member.

According to the charging device of the tenth aspect of the present invention, since the charging member is formed in the shape of a blade, there are no many restrictions on the setting, and there is no loss of hair.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a schematic sectional view showing a charging device according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a conductive fibrous member and a conductive elastic member in FIG. FIG. In FIG. 1, reference numeral 1 denotes a charging device, and the charging device 1 includes a charging blade 2 (charging member) to be brought into contact with an object 9 to be charged, and a supporting member for supporting the charging blade 2 and applying a DC voltage of a power source 4. 3 and 3.

The charging blade 2 includes a charging blade substrate 21
And a conductive fibrous member 22 and a conductive elastic member 23. The charging blade substrate 21 is a rubber blade body made of EPDM, urethane, or the like.

The conductive fibrous member 22 is attached to the lower surface (the lower surface in FIG. 1) of the charging blade substrate 21 with the adhesive 10. The conductive fibrous member 22 is formed of a conductive fibrous substance. As this conductive fiber material, for example, non-woven cloth or cloth woven with regularity,
Alternatively, a material obtained by conducting electrical treatment on electric flocking or the like is used.
As the non-woven cloth or the cloth-like material woven with regularity, for example, a fiber having a base material of PET, PP, rayon, nylon, acrylic or the like, or a composite material thereof,
A metal plated or coated with nickel, copper, or the like, or made conductive by a conductive polymer coat containing a metal filler or carbon can be used.

In the case where electroconductive flocked material is used as the electroconductive fibrous member 22, the electric charging blade base material 21 made of a metal or the charging blade base material 21 coated with a metal film is electrically charged. Flocking is performed, and then a conductive coat such as a metal coat or a conductive polymer coat is used.

The conductive fibrous member 22 has a thickness of 40 when adhered to the charging blade substrate 21.
３００300 μm and the weight is 20-2000 g / m ² . The fiber thickness of the conductive fibrous member 22 is preferably 0.02 to 50 μm. This is 0.02
If it is thinner than 50 μm, it is rather difficult to form a needle electrode structure.
If the thickness is larger than μm, it is difficult to handle in the form of a cloth, and the attachment to the support member 3 may be uneven.

The electric resistance is preferably 10 ¹ to 10 ¹⁰ Ωcm as volume resistance. This depends on the electric resistance of the conductive fibrous member 22 and the applied voltage of the power source 4.
The charging performance of the conductive fibrous member 22 changes, but when the electric resistance is less than 10 ¹ Ωcm, the charged position does not stay on the conductive fibrous member 22, and when the electric resistance exceeds 10 ¹⁰ Ωcm, the predetermined charging performance is not improved. This is because a high voltage must be applied in order to obtain it, which is not preferable.

As shown in FIG. 2, the conductive elastic member 23 is a lattice-shaped member having a plurality of openings L and inclined obliquely with respect to the moving direction of the member 9 to be charged. The lower surface of the fibrous member 22 is attached with an adhesive 11.
The conductive elastic member 23 is made of a rubber material such as hydrin, EPDM, and urethane whose electric resistance is controlled to 10 ¹ to 10 ¹⁰ Ωcm. The electric resistance can be controlled by changing the content of a metal filler, carbon, or the like, and incorporating a conductive polymer. The electric resistance value of the conductive elastic member 23 is related to the conductive fibrous member 22 used at the same time.
It is desirable to make the resistance higher by one digit or more than the electrical resistance of. This is to increase the discharge efficiency of the conductive fibrous member 22.

The opening L can be easily formed by a mold or the like. Here, regarding the size of the opening L, at least a charging process described later can be formed in the vicinity of the contact portion between the charging blade 2 and the charged member 9, and the conductive fiber from the opening L can be formed. The size of the member 22 is set so as to prevent fiber fraying or falling off of the member 22.

The charging blade 2 composed of the charging blade substrate 21, the conductive fibrous member 22, and the conductive elastic member 23 is manufactured as follows. First, the conductive fibrous member 22 is superimposed on the conductive elastic member 23 to which the adhesive 11 is applied, and the conductive fibrous member 22 and the conductive elastic member 23 are bonded. At this time, as shown in FIG.
The right ends of the conductive elastic member 23 and the conductive fibrous member 22 are aligned. On the other hand, the left end of the conductive elastic member 23 is cut in advance by a predetermined length for an electrode 31 described later. Then, the charging blade 2 can be easily manufactured by bonding the charging blade substrate 21 with the adhesive 10 from above the conductive fibrous member 22 to which the conductive elastic member 23 is bonded.

The support member 3 has a structure in which a substantially linear support plate 30 and a substantially L-shaped electrode are fixed. The electrode 31 is electrically connected to the power source 4, and has a tip portion 32 for connecting the power source 4 to the conductive elastic member 23 and a step portion 33 for connecting the power source 4 to the conductive fibrous member 22.
And have.

The charging blade 2 is supported by such a support member 3. Specifically, the charging blade 2
Is press-fitted between the support plate 30 of the support member 3 and the electrode 31 and adhered with the adhesive 12. At this time, the step portion 33 of the electrode 31 is brought into contact with the left end portion of the conductive fibrous member 22 and the tip end portion 32 is brought into contact with the conductive elastic member 23. As a result, the voltage of the power supply 4 is
The voltage is applied to the conductive fibrous member 22 and the conductive elastic member 23 of the charging blade 2. For this reason, the adhesive 1
The adhesive 2 and the above-mentioned adhesives 10 and 11 do not need to be particularly conductive.

In this state, the right side of the charging blade 2 is brought into contact with the surface of the member 9 to be charged, as shown in FIG. 1, through the opening L of the conductive elastic member 23.
A gap G is generated between the lower surface of the conductive fibrous member 22 and the surface of the member 9 to be charged. The gap G is 0.1 to
It is set to 3.5 mm. This is the gap G
Is too narrow, the fibers forming the conductive fibrous member 22 may come into contact with the body 9 to be charged, and when the gap G exceeds 3.5 mm, the charging blade that is attached to the body 9 to be charged. This is because the charging performance of No. 2 is extremely poor. In addition, when the gap G is set to 0.1 to 3.5 mm, particularly preferable charging performance can be obtained.

Next, the operation of this embodiment will be described.
When the object 9 to be charged is conveyed to a position in contact with the charging blade 2 of the charging device 1, the fibers on the surface of the conductive fibrous member 22 connected to the power supply 4 become an aggregate of small needle electrodes. In this state, a minute discharge is performed on the charged body 9 through the opening L of the gap G, and the charged body 9 is charged. Since the surface of the conductive fibrous member 22 cannot be said to be uniform, in this state, the charging of the charged body 9 is not uniform.

However, at the same time, the conductive elastic member 23 connected to the power source 4 and in contact with the charged object 9 is
The charged object 9 is charged by performing charge injection into the substrate and micro discharge. As a result, the charged object 9 is uniformly charged at a predetermined charging level potential by the two-stage charging process. This charging process is performed once or more in the vicinity of the portion where the conductive elastic member 23 of the charging blade 2 and the member 9 to be charged contact. In particular, if they are contacted so as to be performed a plurality of times, they can be effectively and stably charged uniformly.

Further, the conductive elastic member 23 is connected to the member 9 to be charged.
Is formed in a lattice shape obliquely inclined with respect to the moving direction of the conductive member 9, no streak-like charging unevenness occurs on the charged body 9, and the mounting strength and durability of the conductive elastic member 23 are improved. Improvement can be achieved. Further, in the above-described charging process, the frayed fibers of the conductive fibrous member 22 are not exposed from the opening L or fall off.

As described above, according to the charging device of the present embodiment, the charging by the conductive fibrous member 22 having the surface which can be said to be an aggregate of small discharge needles, and the conductive elastic member in contact with the member 9 to be charged. By the two-stage charging process including the charging by the charging member 23, the charged object 9 can be charged uniformly at a predetermined charging level potential.

The conductive fibrous member 22 is opposed to the charged body 9 with a gap G and is arranged in a non-contact state with the charged body 9. The fiber state of the shaped member 22 is not stained or disturbed. Moreover, even if a part of the conductive elastic member 23 is damaged or the like, the charging property is ensured by the conductive fibrous member 22, so that stable charging can be performed, and the charging device 1 with high operation reliability is provided. Can be provided.

In the absence of the conductive elastic member 23, when a pinhole is generated in the charged body 9, the charged body 9 including the pinhole extends in the longitudinal direction (perpendicular to the plane of FIG. 1).
The charge is not spread over the entire surface, and charging failure occurs over the entire surface of the charged body 9 in the longitudinal direction. However, in the charging device 1 of the present embodiment, the conductive fibrous member 22 and the conductive elastic member 23 alternately face the charged object 9 via the opening L in the longitudinal direction of the charged object 9 also. Since the contact is made, the charging failure is only a minute portion of the pinhole portion, and the charging failure over the entire surface of the charged body 9 including the pinhole in the longitudinal direction does not occur.

Even if a charging failure occurs partially, charging is performed at two different stages of the charging process, so that the level of charging failure can be reduced.

Further, the voltage output value from the power supply 4 can be significantly reduced as compared with the corona discharge charging.
Not only safety is ensured, but also ozone generation can be significantly reduced.

Further, since the charging blade 2 can be manufactured by simply stacking the conductive fibrous member 22 and the conductive elastic member 23, the charging device 1 can be easily manufactured.

Also, by changing the characteristics of the conductive fibrous member 22 and the structure and characteristics of the conductive elastic member 23,
It is possible to meet various charging requirements of various charged objects 9.

Further, by moving the contact surface between the charging blade 2 and the body 9 to be charged to some extent, one charging device 1 can be used for a long period of time, so that the running cost can be reduced.

(Second Embodiment) FIG. 3 is a schematic sectional view showing a charging device according to a second embodiment of the present invention, and FIG. 4 shows the conductive fibrous member and the conductive elastic member in FIG. It is the figure which looked at from the bottom. The charging device of this embodiment differs from the charging device of the first embodiment in the structure of the conductive elastic member and the structure of the supporting member.

That is, as shown in FIG. 3 and FIG. 4, a plurality of conductive elastic members 24 of a band-like body having the same width are arranged at equal intervals so as to be inclined with respect to the moving direction of the charged body 9.
It is attached to the conductive fibrous member 22 with an insulating adhesive 13. Thereby, as shown in FIG. 4, the conductive fibrous members 22 and the conductive elastic members 24 are exposed alternately.

By attaching the conductive elastic member 24 in this manner, a large-sized charging blade 2 can be manufactured at low cost. Further, it is possible to easily remove the deposits on the surface of the conductive fibrous member 22 and to release a small amount of ozone generated during operation from the gap of the conductive elastic member 24.

The mounting direction of the conductive elastic member 24 is not particularly limited, and an example is shown in which mounting in this direction is also possible. By mounting in this direction, the escape at the time of ozone generation can be performed together with the movement of the charged body 9.

The support member 5 has a substantially L-shaped electrode 34 fixed to the support plate 30, and the linear electrode 3 is provided on the lower surface of the electrode 34.
5 is attached with an insulating adhesive 14. A power source 6 (first power source) and a power source 7 (second power source) are connected to the electrodes 34 and 35, respectively. That is, DC voltages are applied to the conductive fibrous member 22 and the conductive elastic member 24 from separate power sources 6 and 7.

In the charging process, the role of the conductive fibrous member 22 and the role of the conductive elastic member 24 are different.
For this reason, the power supply 6 can be variably set so that a voltage suitable for the characteristics of the conductive fibrous member 22 can be applied to the conductive fibrous member 22. The voltage can be variably set so that a voltage suitable for the above characteristics can be applied to the conductive elastic member 24.

That is, when the characteristics of the conductive fibrous member 22 and the conductive elastic member 24 change, the moving speed of the charged body 9 changes, or the environment changes, the power supply is changed. 6 and the power supply 7 to control the voltage so that a voltage corresponding to the change can be applied to the conductive fibrous member 22.
And the conductive elastic member 24.

As described above, according to the present embodiment, the voltage of the power supply 6 for the conductive fibrous member 22 and the voltage of the power supply 7 for the conductive elastic member 23 can be changed and controlled. Uniformity and stability of charging can be ensured in response to the requirement. The other configuration and operation and effect are the same as those of the first embodiment, and the description is omitted.

(Third Embodiment) FIG. 5 is a schematic sectional view showing a charging device according to a third embodiment of the present invention. In the charging device of this embodiment, the porous elastic member 40 is attached to the lower surface of the supporting member 8 which also serves as an electrode, and the conductive fibrous member 22 and the conductive elastic member 25 are provided on the surface of the porous elastic member 40. The structure is pasted.

The porous elastic member 40 is formed by forming a porous urethane foam or the like into a semi-cylindrical cross section, and the conductive fibrous member 22 is attached to the curved surface. The conductive elastic member 25 is the conductive elastic member 2 described above.
3 or the same structure as the conductive elastic member 24, and is attached to the surface of the conductive fibrous member 22. The conductive elastic member 25 and the conductive fibrous member 22 are electrically connected at their upper ends to the support member 8 and receive a DC voltage from the power supply 4 via the support member 8. I have.

The charging device according to the third embodiment having the above-described structure is similar to the first and second embodiments described above. A two-stage charging process is performed by the conductive fibrous member 22 and the conductive elastic member 25, and the charged body 9 is uniformly charged at a predetermined voltage level.

Further, since the supporting member 8 has a simple structure having both electrodes, the manufacturing cost can be reduced. Further, since the charging blade is a kamaboko type, it is possible to accurately and easily make contact with the body 9 to be charged. The other configuration, operation, and effect are the same as those of the first and second embodiments, and the description is omitted.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in the first and second embodiments, the charging blade substrate 21 is formed of a rubber blade body made of EPDM, urethane or the like, but may be formed of a metal body.

Further, the structure of the conductive elastic members 23, 24 is not limited to the lattice shape or the band shape, and the opening L and the like can have various shapes. However, in order to prevent charging unevenness, it is desirable to avoid an array that is parallel and perpendicular to the moving direction of the charged body 9.

In the first and second embodiments, the charging blade substrate 21 and the support members 3, 5 are formed separately, but they may be formed integrally.

Although the power supplies 4, 6, and 7 are DC power supplies, it is effective to superimpose an AC voltage on a DC voltage when more uniform charging and environmental compatibility are required. In particular, a frequency of 20 to 1000 Hz, preferably 100 to 5
00 Hz AC voltage is superimposed on the conductive fibrous member 2.
In the charging process of 2 or the conductive elastic members 23, 24, 25, the charging / reverse charging process can be repeated,
Thereby, local uneven charging can be eliminated.

[0070]

As described above, according to the charging device of the first aspect, the object to be charged is charged by a two-stage charging process of charging by the conductive fibrous member and charging by the conductive elastic member. Therefore, the member to be charged can be charged uniformly at a predetermined charging level potential.

Further, since the charging member is arranged so as to be exposed alternately on the side contacting the member to be charged,
Even if a pinhole is generated on the member to be charged, it is possible to prevent the occurrence of a situation in which charging failure occurs over the entire surface of the portion that contacts the charging member.

Even if a charging failure occurs partially, charging is performed at two different stages of the charging process, so that the level of charging failure can be reduced.

Further, since the voltage output value from the power supply can be greatly reduced as compared with the corona discharge charging, the safety can be ensured and the generation of ozone can be greatly reduced.

Further, since the charging member can be formed by simply arranging the conductive fibrous members and the conductive elastic members so as to be alternately exposed, the charging device can be easily manufactured. At the same time, the charging member can be formed into various shapes.

Further, by slightly moving the contact surface between the charging member and the member to be charged, one charging device can be used for a long period of time, so that the running cost can be reduced.

According to the charging device of the second aspect of the present invention,
Since the conductive fibrous member faces the member to be charged at a predetermined gap and is disposed in a non-contact state with the member to be charged, the fibrous state of the conductive fibrous member due to the member to be charged is disturbed or disturbed. Can be prevented. Moreover, even if a part of the conductive elastic member is damaged or the like, the charging property is ensured by the conductive fibrous member, so that stable charging can be performed and a charging device with high operation reliability is provided. be able to.

According to the charging device according to the third to seventh aspects of the present invention, the characteristics of the conductive fibrous member and the structure and characteristics of the conductive elastic member can be changed. It can respond to various charging requirements of the body.

According to the charging device of the invention of claim 8,
Since the voltage applied to the conductive fibrous member and the voltage applied to the conductive elastic member can be changed and controlled, uniformity and stability of charging can be ensured for all charging requirements.

According to the charging device of the ninth aspect,
Since the DC voltage on which the AC voltage is superimposed is applied to the charging member, the charging / reverse charging process can be repeated in the charging process of the charging member, whereby local uneven charging can be eliminated.

According to the charging device of the tenth aspect of the present invention, since the charging member is formed in a blade shape, there is no much restriction in setting as in the charging device by brush charging, and hair is not removed. No problem such as For this reason,
Excellent charging uniformity and operational reliability.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a charging device according to a first embodiment of the present invention.

FIG. 2 is a view of the conductive fibrous member and the conductive elastic member of FIG. 1 as viewed from below.

FIG. 3 is a schematic sectional view showing a charging device according to a second embodiment of the present invention.

FIG. 4 is a view of the conductive fibrous member and the conductive elastic member of FIG. 3 as viewed from below.

FIG. 5 is a schematic sectional view showing a charging device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charging device 2 Charging blade 3 Support member 4 Power supply 9 Charged body 21 Charging blade base material 22 Conductive fibrous member 23 Conductive elastic member 31 Electrode

Claims (10)

[Claims] 1. A charging device for charging a member to be charged by bringing the member to be charged into contact with the member to be charged, wherein the charging member is alternately exposed on a surface contacting the member to be charged. A conductive fibrous member and a conductive elastic member disposed in the charging device. 2. The conductive fibrous member is arranged so as to face the charged body with a predetermined gap when the conductive elastic member contacts the charged body. Charging device. 3. The charging device according to claim 1, wherein the conductive elastic member is laminated on the surface of the conductive fibrous member and has a plurality of openings. 4. The charging device according to claim 1, wherein the conductive elastic member is a plurality of strips laminated at predetermined intervals on the surface of the conductive fibrous member. 5. The gap is 0.1 mm to 3.0 m.
The charging device according to any one of claims 1 to 4, wherein m is m. 6. The electric resistance value of the conductive fibrous member and the electric resistance value of the conductive elastic member are set to 10 ¹ to 10 ¹⁰ Ωcm.
The charging device according to any one of claims 1 to 5, wherein the charging device is set in the range of: 7. The charging device according to claim 6, wherein the electric resistance value of the conductive fibrous member is different from the electric resistance value of the conductive elastic member. 8. The first power source is connected to the conductive fibrous member, and the second power source is connected to the conductive elastic member.
The charging device according to claim 7. 9. The charging device according to claim 1, wherein the voltage of the power source is a DC voltage on which an AC voltage is superimposed. 10. The charging device according to claim 1, wherein the charging member is formed in a blade shape.