JP2002091160A - Developing device - Google Patents

Abstract

(57) [Problem] To provide a developer transport member that generates a traveling-wave electric field, the developer is charged by the developer, or the developer adheres to the surface, and the transport of the developer becomes unstable. An endless belt-like covering member (2) for covering a peripheral surface of a developer carrying member (21) for carrying a developer by a traveling wave electric field.
2, the coating member 22 is moved with respect to the developer conveying member 21. The developer is conveyed on the covering member 22 by the traveling wave electric field without contacting the developer conveying member 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing an electrostatic latent image formed on an image carrier using a developer or the like, and more particularly, to a mechanism for transporting the developer using a traveling wave electric field. The present invention relates to a developing device used.

[0002]

2. Description of the Related Art As a developing method applied to an image forming apparatus using an electrophotographic process such as a copying machine and a printer,
At present, a non-contact type developing device that performs development without bringing a developer carrier into contact with an image carrier has attracted attention, and methods using a powder cloud method, a jumping method, and an electric field curtain (a traveling wave electric field) have been proposed. Have been.

As a method using an electric field curtain, for example, there is a developing device disclosed in Japanese Patent No. 2836537. The developing device includes a transport path as developer transport means for transporting the developer from the developer accommodating section toward the image carrier, and a developing device which is disposed below the transport path and collects unnecessary developer from the image carrier. The image forming apparatus includes a collection path serving as an agent collection unit, and a developing electrode provided at an end of the conveyance path on the image carrier side and facing the image carrier and directed downward.

[0004] An electrode for generating an electric field curtain action is embedded in the transport path, and the developer is stirred and charged by the electric field curtain action to transport the developer to a developing position. The developer transported to the developing position is moved toward the image carrier by a developing electric field generated by the surface charge of the image carrier and the developing bias applied to the developing electrode, and the electrostatic latent image is developed. The developer that has not adhered to the image carrier drops from the developing electrode, proceeds to the recovery path, is excited, and is recovered in the developer container.

[0005] With such a configuration, the developer is conveyed by a traveling-wave type AC electric field without using mechanical power to develop the electrostatic latent image, and the developer not contributing to the development is removed. It can be collected and reused, and the device is simplified and downsized.

[0006]

However, in the above-described developing device, the transport path carrying the developer may be charged by applying a voltage to the electrode or contacting the developer, and the like. Curtain formation may be unstable. Further, the developer may adhere to the transport path, and the transport of the developer is hindered. As described above, there is a problem that the conveyance of the developer becomes unstable, and as a result, stable image formation cannot be obtained.

In view of the above, it is an object of the present invention to provide a developing device capable of forming a stable image by reliably transporting a developer.

[0008]

According to the present invention, there is provided a developer transporting member for transporting a developer toward an image carrier by a traveling wave electric field, comprising a covering member for covering a peripheral surface thereof. This is to move the covering member. According to this, the developer moves on the covering member by the traveling wave electric field formed by the developer transport member, and the developer is transported without contacting the developer transport member. Therefore, the developer transport member is not charged or the developer is not fixed, and a stable traveling wave electric field is formed, so that the developer can be transported reliably.

At this time, since the covering member is moving,
Different surfaces will always face the image carrier,
The effects of charging by the developer and the effects of the adhesion of the developer can be eliminated, and the transport of the developer is not hindered. Here, the moving speed of the covering member is desirably set to a speed that can be regarded as substantially stationary with respect to the developer to be conveyed. That is, if the moving speed is high, the layer of the developer to be conveyed is disturbed by the wind pressure, and the distribution of the developer may be non-uniform. Suppressed and uniform layer of developer can be formed.

[0010] The covering member may be an endless belt,
A finite belt shape or a sheet shape may be used. In particular, an endless belt shape is optimal because it can be used endlessly and a mechanism for moving it can be simplified. Further, by setting the volume resistivity of the covering member to 10 ⁸ to 10 ¹⁷ Ω · cm, it is possible to remove the electricity from the covering member, to obtain a stable electric field, and to stably transport the developer. The volume resistivity is desirably 10 ⁸ to 10 ¹⁴ Ω · cm. By using a material, the charge of the covering member can be more easily removed, and the developer can be transported more stably by obtaining a stable electric field. .
Furthermore, when the covering member is brought into close contact with the developer transport member, uniformity of the electric field can be maintained, and uneven transport of the developer is eliminated.

Here, when the covering member is in the form of an endless belt or a finite belt or sheet and is repeatedly used by being reciprocated, the charge removing member for removing the charge of the covering member is moved in the image carrier in the developer conveying direction. Is provided on the downstream side of the location facing the. Further, a cleaning member for removing the developer that did not contribute to the development from the covering member may be provided, and the cleaning member may be disposed downstream of the charge removing member. If a conductive material is used as the cleaning member, not only cleaning but also static elimination can be performed, so that two members can be integrated into one, and the apparatus can be downsized.

With this configuration, when the covering member passes through the image carrier and reaches the developer conveying member again, since the covering member is neutralized, it adversely affects the formation of the traveling wave electric field by the developer conveying member. And the developer can be stably conveyed. Further, since the developer attached to the covering member is reliably removed by the cleaning member, it is possible to prevent the developer from sticking due to defective cleaning,
A good image without defects can be obtained. Moreover, static elimination members,
If the cleaning member and the cleaning member are arranged in this order, the charge is removed first, so that the developer is easily removed from the covering member.

Further, a supply member is provided at a position where the covering member contacts the developer conveying member on the upstream side in the developer conveying direction. The developer is charged by the supply member and supplied to the covering member, so that the transport of the developer by the traveling wave electric field is stabilized. When the charge removing member and the cleaning member are arranged close to the supply member, it is possible to prevent the covering member from being charged by the contact of the developer or the like after the charge removal, and to increase the stability of the developer conveyance.

The direction of movement of the covering member may be the same as the direction of transport of the developer, but if the direction is reversed, the removed and cleaned covering member moves toward the image carrier. In addition, it is possible to eliminate the influence of the charging by the developer and the adhesion of the developer, and it is possible to obtain a stable transport of the developer.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows an example of an image forming apparatus using an electrophotographic process to which a developing device of the present invention is applied. In this electrophotographic process, a document image or an electrostatic latent image corresponding to data from a host computer is formed on a photoreceptor 1 as an image carrier, and the electrostatic latent image is visualized by a developer from a developing device 2. Then, the image is transferred onto a recording medium 3 such as paper to form an image.

Around the photosensitive member 1, a charging device 4, an exposure device 5, a developing device 2, a transfer device 6, a cleaning device 7,
The static eliminators 8 and the like are arranged in order from the upstream side in the rotation direction of the photoconductor 1. Further, a fixing device 9 is disposed downstream of the recording medium 3 in the transport direction.

The photoreceptor 1 has a photoconductive layer 11 such as amorphous silicon (a-Si), selenium (Se), or an organic optical semiconductor (OPC) on the outer peripheral surface of a metal drum of aluminum or the like as a base material 10. Are formed in a thin film shape.

The charging device 4 is, for example, a charging wire such as a tungsten wire, a metal shield plate, a corona charger made of a grit plate, a charging roller, a charging brush, or the like. The exposure device 5 is a semiconductor laser. The transfer device 6 is, for example, a corona charger, a charging roller, a charging brush, or the like. The detailed configuration of the developing device 2 will be described later.

The photosensitive member 1 is first uniformly charged by the charging device 4 and then irradiated with light by the exposure device 5 in accordance with image information. In this way, an electrostatic latent image is formed on the photoconductor 1, and the developer (toner) in the developing device 2 is moved by the developing electric field formed between the photoconductor 1 and the developing device 2, and the electrostatic latent image is formed. The latent image is visualized as a toner image. This toner image is transferred onto the recording medium 3 by the transfer device 6 and is fixed by heating in the fixing device 9. After the transfer of the toner image, the toner remaining on the photoconductor 1 is removed by a cleaning device 7 having a cleaning blade or the like, and the electric charge remaining on the photoconductor 1 is removed by a static elimination device 8 such as a static elimination lamp. Static electricity is removed.

Next, the developing device 2 will be described. As shown in FIG. 2, in the developing device 2, a toner transport member (developer transport member) 21 that generates a traveling-wave electric field and transports the toner in a developing tank 20 containing a toner as a developer.
Covering member 2 that moves while covering toner conveying member 21
2. A supply member 23 for supplying the toner to the toner conveying member 21, a rotatable MX (mixing) paddle 24 for supplying the toner in the developing tank 20 to the vicinity of the supply member 23 and stirring the toner, and a covering member 22. A charge removing member 25 for removing charge and a cleaning member 26 for removing toner from the covering member 22 are provided.

The developing tank 20 is arranged opposite to the side of the photoreceptor 1, and has an opening 27 on the side opposite to the photoreceptor 1. The toner conveying member 21 is positioned so as to face the opening 27.
Are fixed to the support member 28 and transport the toner upward from below. Therefore, the opening 27 is formed by the toner conveying member 21 and the covering member 22 that covers the toner conveying member 21.
Is closed, and the toner container 29 is formed inside the developing tank 20.

At the lower edge of the opening 27, an inclined surface protruding toward the photoreceptor 1 is formed. Although the toner supplied to the toner conveying member 21 is charged by the supplying member 23, there is a possibility that there is a toner having a low charge amount, and such toner may drop during the conveyance. There is. Therefore, receiving part 3
0 receives the toner and prevents the toner from scattering.

As shown in FIG. 3, the toner conveying member 21 is made of a base material 31 made of, for example, polyimide (having a thickness of 25 μm).
m), a traveling wave generating electrode 32 made of copper foil (18 μm in thickness) is formed, and a surface protection layer 33 made of polyimide (25 μm in thickness) is laminated thereon. As described above, since the toner conveying member 21 can be formed to be very thin and elastic, the toner conveying member 21 can be attached with a curvature to the support member 28 curved toward the photosensitive member 1. . The area of the toner conveying member 21 closest to the photoconductor 1 is defined as a development area A.

Here, the traveling wave generating electrode 32 constituting the toner conveying member 21 will be described. Traveling wave generating electrode 3
2 is a microelectrode 32a having a width of 40 to 130 μm, for example.
00 dpi (about 254 μm) to 300 dpi (about 85 μm)
m) A plurality of sets of three or four microelectrodes 32a are formed so as to be parallel to each other while maintaining a pitch interval.

A three-phase or four-phase alternating voltage (a voltage containing a polyphase AC component) is applied to each pair of electrodes 32a by a polyphase AC power supply 34. That is, as shown in FIG. 4, when a pulse voltage (in this case, a four-phase pulse voltage) having a predetermined phase difference is applied to each of the electrodes, a traveling wave electric field is formed on the traveling wave generating electrode 32, The toner is transported.

The alternating voltage applied to the traveling wave generating electrode 32 is set to a value of, for example, about 100 V to 1000 V so that dielectric breakdown does not occur between the electrodes 32 a, and the frequency is set to a value within a range of 100 Hz to 100 kHz. Is used. The alternating voltage and the frequency may be set to appropriate values depending on the shape of the element of the traveling wave generating electrode 32, the conveying speed of the toner, the material used for the toner, and the like. The toner conveying member 21 includes the photosensitive member 1 and the toner conveying member 21.
The developing bias DC power supply 35 applies a DC voltage so that a developing electric field is formed between the DC voltage and the developing voltage.

The covering member 22 is in the form of an endless belt and covers the peripheral surface of the toner conveying member 21 facing the photoreceptor 1, so as to prevent the toner conveying member 21 from being charged and to prevent the toner from sticking. belongs to. Materials include polyimide, PET (polyethylene terephthalate), polytetrafluoroethylene, polyfluoroethylene propylene, P
It is obtained by dispersing or compatibilizing carbon black or an ionic conductive material in an organic insulating material such as TFE (polytetrafluoroethylene) or a rubber material such as silicon, isoprene or butadiene. The volume resistivity of the cover member 22 is 10 ⁸ ~10 ^{1 7} Ω · cm is adequate, 10 ¹² Ω · c
If it is more than m, it is difficult to remove the charge of the covering member 22. Also, 1
When the resistance is less than 0 ⁸ Ω · cm, the electric field formed by the traveling wave generating electrode 32 is shielded due to a decrease in resistance, and a sufficient electric field is not formed on the covering member 22, making it difficult to transport the toner. become. The covering member 22
Can be neutralized even at a volume resistivity of 10 ¹⁴ to 10 ¹⁷ Ω · cm, but is preferably 10 ⁸ to 10 ¹⁴ Ω · cm.
By doing so, it is possible to more easily remove static electricity.

As shown in FIG. 5, the thickness of the covering member 22 is d μm, the pitch between the traveling wave generating electrodes 32 is λ μm,
When the thickness of the surface protection layer 33 is set to d, in order to make the electric field generated at the electrode 32 effectively act on the toner, d + △
It is necessary that d ≦ λ. When d10 △ d> λ, the formed electric field is weakened, and there is a possibility that the toner cannot be sufficiently conveyed. Therefore, the thickness of the covering member 22 is set so that d ≦ λ− △ d <λ. For example, λ = 12
When the thickness is 0 μm, the thickness △ d of the surface protection layer 33 is considered,
Let d = 80 μm. By setting the thickness of the covering member 22 in this manner, a stable traveling wave electric field can be formed, and the toner can be transported stably.

The covering member 22 is wound around a driving roller 40 and a driven roller 41 which are arranged vertically, and is moved in the direction of arrow B (the same direction as the toner conveying direction) by rotating the driving roller 40 clockwise. Is done. As described above, the covering member 22 is supported by the driving roller 40, the driven roller 41, and the toner conveying member 21 at at least three points, so that the covering member 22 is in close contact with the toner conveying member 21. The covering member 22 and the toner conveying member 21 are not in close contact with each other;
That is, if there is a gap between the two, the voltage applied by the traveling wave generating electrode 32 is distributed,
There is a possibility that the electric field formed on the upper surface is weakened, so that sufficient toner cannot be conveyed. Although the covering member 22 is arranged in non-contact with the photoconductor 1, the covering member 22 may be arranged so as to be in contact with the photoconductor 1, and development may be performed.

The supply member 23 is composed of a supply roller made of a material such as a sponge type urethane foam, and is rotatably opposed to the lower end of the toner conveying member 21 with the covering member 22 sandwiched below the developing tank 20. And is rotated counterclockwise by a motor (not shown) or the like. As a result, the toner in the toner container 29 is charged in a desired polarity direction, and the charged toner is
2 and supply while regulating the layer thickness. The supply member 23
May be connected to a DC power supply. Also, the supply member 2
Numeral 3 is in sliding contact with the covering member 22 and also in sliding contact with the bottom surface of the developing tank 20.
It prevents leakage outside.

The static elimination member 25 is a static elimination roller made of a metal such as aluminum, iron, or copper, or a material such as carbon black, urethane rubber, silicon rubber, or EPDM (ethylene propylene) to which an ionic conductive material is added.
It is rotatably arranged above the developing tank 20 so as to face the toner conveying member 21 with the covering member 22 interposed therebetween, and is rotated counterclockwise. The charge removing member 25 removes the charge of the covering member 22, collects the toner that has not contributed to the development to the toner storage unit 29, and supplies the refreshed covering member 22 to the photoconductor 1 at all times. .

The cleaning member 26 is made of stainless steel,
It is made of a plate-like material such as nickel-coated iron, urethane or silicon rubber, and faces the driven roller 41 downstream of the charge removing member 25 in the toner conveying direction, and has a contact end with the covering member 22 opposite to the moving direction. It is arranged to face the side. Note that, as the cleaning member 26, a roller,
A brush may be used. As a result, the residual toner on the covering member 22 is scraped off and cleaned, and the toner is returned to the toner container 29 again.

As the cleaning member 26, a material obtained by mixing a conductive material such as carbon black or ions with urethane rubber, silicon rubber, EPDM (ethylene propylene), or the like, or the above stainless steel, nickel-coated iron, aluminum, By using a conductive material such as a metal such as copper, not only the toner is scraped off, but also the charge removing member 25 may be used so as to remove the charge of the covering member 22, and it is not necessary to separately provide the charge removing member 25.

The partition wall 4 extends from a position higher than the top surface of the stored toner to the bottom surface of the toner storage portion 29.
2 is provided along the covering member 22, and the covering member 22 is isolated from the toner container 29. The partition wall 42 can prevent the toner from adhering to the surface of the cleaned covering member 22 before the covering member 22 reaches the supply member 23.

Next, the developing operation of the developing device 2 will be described. The toner stored in the toner storage unit 29 is MX
The mixture is stirred by the paddle 24 and supplied to the vicinity of the supply member 23. The toner existing near the supply member 23 is charged by the supply member 23 and supplied to the toner transport member 21. The toner charged through this process is conveyed in the direction of arrow B on the surface of the covering member 22 without directly touching the toner conveying member 21 by the traveling wave electric field formed by the toner conveying member 21, and is exposed in the developing area A. The electrostatic latent image on the body 1 is developed. The toner that has not contributed to the development is further transported in the B direction, and
If the electric charge on the cover 2 is removed, and there is toner fixed on the covering member 22, the toner is removed from the covering member 22 by the cleaning member 26 and returns to the toner container 29 again.

At this time, the covering member 22 is driven in the direction B, which is the same as the toner conveying direction, so slowly that it is regarded as being substantially stationary with respect to the toner conveying speed. That is,
Regarding the relationship between the moving speed of the covering member 22 and the toner carrying speed, when the toner is carried by the traveling wave electric field and the covering member 22 is driven, the moving speed of the covering member 22 must be set appropriately for the toner carrying speed. In addition, uniform toner conveyance cannot be performed. For example, when the covering member 22 moves, the toner (cloud-like toner) being conveyed may be disturbed by an air current generated in the vicinity of the covering member 22 and may become non-uniform. Therefore, it is preferable to control the driving speed of the covering member 22 at a level that is considered to be substantially stationary with respect to the toner transport speed. . Here, as described in the following literature, for example, a method of providing two infrared sensors and detecting a time when toner arrives by a toner detection signal from each sensor, or a high-speed video It can be measured by measuring with a camera (IS & Ts NIP15:
1999 International Conference on Digital Printing
Technologies p.262-265 `` Aspects of Toner Transpor
t on a Traveling Wave Device ”).

(Second Embodiment) In the present embodiment, as shown in FIG.
Is provided in the toner container 29 so as to face the drive roller 40 with the covering member 22 interposed therebetween, and is disposed in the moving direction of the covering member 22 in the order of the charge removing member 25 and the cleaning member 26 in the vicinity of the supply member 23. Other configurations are the same as those of the first embodiment.

Thus, the distance over which the refreshed surface after the charge elimination and cleaning moves to the developing area A can be shortened. Therefore, there is no possibility that the surface of the covering member 22 is charged by the toner or the like in the toner container 29 after the charge elimination and cleaning, and the toner can be transported while maintaining the refreshed surface up to the development area A.

(Third Embodiment) In the present embodiment, as shown in FIG. 7, the drive roller 40 is driven to rotate so that the moving direction of the covering member 22 is in the direction of arrow C opposite to the toner conveying direction. Then, the charge removing member 25 is disposed so as to face the upper end of the toner conveying member 21 with the covering member 22 interposed therebetween. Further, the cleaning member 26 is arranged such that the contact end with the covering member 22 is directed to the opposite side to the moving direction.
The moving speed of the covering member 22 is the same as or slower than that in the above embodiment. Other configurations are the same as those of the first embodiment.

As a result, the covering member 22 whose surface has been neutralized and cleaned moves toward the developing region A, so that the clean surface of the covering member 22 faces the developing region A, and stable development can be performed. . Further, when the charge removal and cleaning of the cover member 22 are performed, for example, in the developing device 2 illustrated in FIG. 6, the toner in the toner storage unit 29 may enter between the cover member 22 and the charge removal member 25 or the cleaning member 26. However, in the above configuration, the toner in the toner storage portion 29 is
Such a problem does not occur because the cleaning member 26 scrapes off the paper even if it is adhered to and transported.

Incidentally, the toner conveyed by the toner conveying member 21 and not contributing to the development is applied to the covering member 22.
And the cleaning member 26 may collect in the space D. Therefore, a separating mechanism for separating the cleaning member 26 from the covering member 22 is provided, and the toner accumulated between the cleaning member 26 and the covering member 22 is periodically separated from the covering member 22 to the toner container 29. I will put it back.

That is, as shown in FIG. 8, a holding member 43 for holding the cleaning member 26 is rotatably supported around a shaft 43a as a separating / contacting mechanism, so that the cleaning member 26 is pressed against the covering member 22 in the direction of pressing. An elastic member (not shown) such as a biasing spring is provided. An eccentric cam 44, which is rotationally driven by a motor (not shown), is provided in the vicinity of the cleaning member 26. When the eccentric cam 44 rotates in the direction of arrow E, the cleaning member 26 moves in a direction opposite to the direction urged by the elastic member. , The toner rotates in the direction away from the covering member 22, and the toner stored in the space D falls and returns to the toner storage unit 29. When the eccentric cam 44 rotates in the direction of arrow F, the cleaning member 26 rotates in a direction approaching the covering member 22 and presses against the covering member 22. The eccentric cam 44 has two locking members 4
Since the movable range is set by 5 and 46,
The separation and contact of the cleaning member 26 can be reliably controlled. Note that the cleaning member 26 may be directly separated from and brought into contact with the covering member 22 by a solenoid, and the mechanism for separating and connecting the cleaning member 26 is not limited to the above.

Further, a plurality of such cleaning members 26 are arranged so that any one of the cleaning members 26 is always in contact with the covering member 22 so that the toner adhered to the covering member 22 is surely removed. You may.

It should be noted that the present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention. In each embodiment, instead of providing the charge removing member, the charge can be removed by a driving roller or a driven roller. Aluminum, as the material of the drive roller and the driven roller,
Metals such as iron and copper, or carbon black, urethane rubber, silicon rubber, EPD with ionic conductive material added
Using a conductive material such as M (ethylene propylene), static electricity is removed from the covering member so as to make contact with the back surface side of the covering member. In this case, it is suitable for the developing devices of the second and third embodiments, which can quickly supply the charge-removed covering member to the developing area.

The covering member is not limited to an endless belt shape, but may be a finite belt shape, or may be moved by winding both ends around a reel. At this time, if the reciprocating movement is performed by switching the moving direction in accordance with the timing of image formation, it can be used repeatedly like the endless belt. Alternatively, the covering member may be formed in a sheet shape and reciprocated.

[0046]

As is apparent from the above description, according to the present invention, the peripheral surface of the developer transport member for transporting the developer by the traveling wave electric field is covered with the covering member, and the covering member is moved to develop the developer. The developer is not directly conveyed on the developer conveying member, so that charging of the developer conveying member and sticking of the developer can be prevented. Therefore, the electric field formed by the developer conveying member is stable,
The developer can be smoothly transported toward the image carrier, and stable image formation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus using a developing device of the present invention.

FIG. 2 is a configuration diagram of a developing device according to the first embodiment.

FIG. 3 is a configuration diagram of a toner conveying member.

FIG. 4 is a timing chart of a voltage waveform applied to the toner conveying member.

FIG. 5 is a view for explaining the relationship between the thickness of the covering member and the pitch between the electrodes of the toner conveying member.

FIG. 6 is a configuration diagram of a developing device according to a second embodiment.

FIG. 7 is a configuration diagram of a developing device according to a third embodiment.

FIG. 8 is a diagram illustrating a separation / contact mechanism of a cleaning member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor 2 developing device 20 developing tank 21 toner transport member (developer transport member) 22 coating member 23 supply member 25 static elimination member 26 cleaning member 27 opening 29 toner storage portion 30 receiving portion

Claims (13)

[Claims] 1. A developing device for developing an electrostatic latent image formed on an image bearing member arranged oppositely, comprising: a plurality of electrodes arranged at predetermined intervals; To form a traveling-wave electric field by applying a voltage containing a polyphase AC component to the developer, conveying the developer toward the image carrier by the traveling-wave electric field; A covering member that covers the surface and moves with respect to the developer conveying member, wherein the developer moves on the covering member. 2. The developing device according to claim 1, wherein the covering member has an endless belt shape. 3. The coating member has a volume resistivity of 10 ⁸ to 10 ^17.
The developing device according to claim 1, wherein the developing device has a resistance value of Ω · cm. 4. The developing device according to claim 1, wherein d <λ when the thickness of the covering member is d mm and the pitch between the electrodes of the developer conveying member is λ mm. 5. The developing device according to claim 1, wherein the covering member is in close contact with the developer conveying member. 6. The developing device according to claim 1, wherein the covering member moves at a speed that is considered to be substantially stationary with respect to the developer conveyed by the traveling wave electric field. 7. The developing device according to claim 1, further comprising a charge removing member for removing charge from the covering member. 8. The developing device according to claim 1, further comprising a cleaning member for removing a developer that did not contribute to development from the covering member. 9. The developing device according to claim 8, wherein the cleaning member is made of a conductive material. 10. The developing device according to claim 1, wherein the moving direction of the covering member is opposite to the direction in which the developer is conveyed. 11. A developer container for storing a developer, wherein an opening is formed to open toward the image carrier, and a developer conveying member is formed in the opening so as to convey the developer from below to above. 3. The developing device according to claim 1, wherein a receiving portion that receives the developer that has fallen is provided at a lower edge of the opening. 12. An opening opening toward an image carrier is formed in a developing tank for storing a developer, a developer conveying member is disposed in the opening, and a charge removal of a coating member is performed in the developing tank. And a cleaning member that removes a developer that did not contribute to development from the coating member is provided,
2. The cleaning member according to claim 1, wherein the cleaning member is disposed downstream of the charge removing member in a developer conveying direction.
Or the developing device according to 2. 13. An opening opening toward an image carrier is formed in a developing tank containing a developer, a developer conveying member is disposed in the opening, and a charge is applied to the developer in the developing tank. A supply member that charges the developer by applying and supplies the developer to the endless belt-shaped covering member, a charge removing member that removes the charge of the covering member, and a developer that has not contributed to the development from the covering member. The developing device according to claim 1, further comprising a cleaning member to be removed, and wherein the cleaning member and the charge removing member are arranged near the supply member.