JP2002099142A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which can carry a developer more smoothly and securely by eliminating various problems impeding the conveyance of the developer when a mechanism (electric field curtain) carrying the developer by using a traveling wave electric field is used and an image forming device of high quality equipped with the developing device. SOLUTION: This developing device is equipped with a developer carrying means 11 which carries the developer by producing the traveling wave electric field with a polyphase voltage applied to electrodes 113 arrayed in a base material 114 at specific intervals and a nearly cylindrical supply means 13 which comes into contact with the surface of the developer carrying means 11 rotatably and supplies the developer 17 to the developer carrying means 11, and the developer carrying means 11 is arranged in a development area facing the image carrier carrying an electrostatic latent image on its surface. Further, the device is equipped with a light irradiation means 15 which emits light, and the developer carrying means 11 is provided with a photoconductive layer 111 to be irradiated with the light by the light irradiating means 15 in an area including at least the contact part with the supply means 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and an image forming apparatus, and a developing device for developing an electrostatic latent image formed on a latent image carrier (image carrier) using a developer or the like. More particularly, the present invention relates to a developing device using a mechanism (electric field curtain) for transporting a developer using a traveling wave electric field, and an image forming apparatus including the same.

[0002]

2. Description of the Related Art Image forming apparatuses using an electrophotographic process, such as a copying machine, a printer, and a facsimile, are known. As a developing apparatus applied to these image forming apparatuses, a two-component system using a magnet brush is used. There has been known a developing device or a system in which a one-component developer is pressed against a developer carrier such as a developing roller by a blade or the like to form a thin layer and is brought into contact with a photoconductor as an image carrier to perform development. Yes,
It has already been put to practical use.

On the other hand, a non-contact type developing device which performs development without bringing a developer carrier into contact with an image carrier has attracted attention, and uses a powder cloud method / jumping method or an electric field curtain (traveling wave electric field). A method has been proposed. For example, a developing device using an electric field curtain is as follows. JP-A-3-21967 discloses the following technology. A precharging unit for precharging the developer conveyed by the developer carrying carrier and an electric field curtain generating unit for applying an electric field curtain on the developer carrying carrier are provided. As the pre-charging means, a pre-charging roller made of, for example, urethane foam is used, and the pre-charging roller is provided so as to be in contact with the developer-carrying carrier, and a blade is provided so that the front end is in contact with the pre-charging roller. Is provided. The pre-charging roller performs pre-charging of the developer by rubbing the developer with the developer carrying member, and also controls the layer thickness of the developer.

According to the above configuration, the developer can be uniformly charged to an appropriate charge amount, and the developer can be stably transported to the image carrier.
As a result, it is possible to prevent the developer from being scattered at the time of transport and to prevent fogging of the formed image.

However, in the above prior art,
This leads to the following problems. If the pre-charge roller is rotated while being brought into contact with the developer carrying carrier, the developer carrying carrier may be charged and may not be able to carry the developer stably. Nothing is said about this problem. From the viewpoint of making the layer thickness of the developer supplied to the developer carrying carrier uniform, it is disclosed that the pre-charging roller is rotated in a direction opposite to the rotation direction of the developer carrying carrier. However, nothing is said about stably transporting the developer.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to use a mechanism (electric field curtain) for transporting a developer using a traveling wave electric field. In addition, it is an object of the present invention to provide a developing device capable of solving the problems that hinder the transport of the developer and enabling the developer to be transported more smoothly and reliably, and a high-quality image forming apparatus including the developing device. It is in.

[0007]

According to the present invention, there is provided a developing method in which a traveling-wave electric field is formed by a multi-phase voltage applied to a plurality of electrodes arranged at predetermined intervals in a base material to transport a developer. A developer transporting means, and a substantially cylindrical supply means for rotatably contacting the surface of the developer transporting means and supplying the developer to the developer transporting means; and A developing device arranged in a developing region opposed to an image carrier that carries an electrostatic latent image on the surface thereof, comprising: a light irradiating unit that irradiates light; The developing device includes a photoconductive layer to which the irradiation unit irradiates light at least in a region including a contact portion with the supply unit.

When the supply means rotatably contacts the developer conveying means, not only the developer conveyed on its surface but also the developer conveying means is charged, and as a result, the developer is stably conveyed. May be hindered. On the other hand, according to the above configuration, the photoconductive layer is formed at least in the vicinity of the contact portion of the supply unit, and the photoconductive layer is periodically irradiated with light by the light irradiation unit, so that the charged development is performed. It becomes possible to eliminate the charge of the agent conveying means. Therefore, the developer can be transported more stably.

[0009] Further, there is provided a developing device in which the photoconductive layer is formed of a material exhibiting ambipolar conductivity.

According to the above construction, since the photoconductive layer exhibits ambipolar conductivity, the charge can be reliably removed regardless of the polarity of the triboelectric charge generated by the contact between the supply means and the developer transport means. it can.

Further, the present invention is the developing device, wherein the electrodes arranged in the area where the photoconductive layer is provided in the developer conveying means are transparent electrodes.

According to the above configuration, since the electrode is a transparent electrode, the light is not blocked by the electrode even when the light is irradiated on the photoconductive layer by the light irradiating means. Irradiation with light enables more uniform charge removal.

Further, the present invention provides a developing device for applying a predetermined DC voltage to at least one of a plurality of electrodes in a supply unit and a developer conveying unit at the time of irradiating light by the light irradiating unit. It is.

According to the above structure, the electric field formed in the photoconductive layer is strengthened, so that the charged developer conveying means can be more quickly discharged.

Further, the present invention is a developing device wherein the light irradiation by the light irradiation means is performed every time one developing operation is completed.

According to the above arrangement, each time one developing operation is completed, that is, each time the image forming apparatus having the developing device of the present invention completes one image forming operation, the developer conveying means is discharged. Will be. Therefore, the developer can be stably conveyed every time an image forming operation is performed, and the quality of an image formed by the image forming apparatus including the developer according to the present invention can be further improved.

According to the present invention, there is provided a developer transporting means for transporting the developer by forming a traveling-wave electric field by a multiphase voltage applied to a plurality of electrodes arranged at a predetermined interval. In a developing device in which the developer conveying means is arranged in a developing region opposed to an image carrier that carries the electrostatic latent image on its surface, the developing device is rotatably contacted with the surface of the developer conveying means, and A supply unit having a substantially cylindrical shape for supplying the developer conveyed on the surface; and a rotation direction of the supply unit on the surface is a forward direction with respect to a conveyance direction of the developer. Developing device.

According to the above arrangement, at the contact portion (nip portion) between the developer conveying means and the supplying means, the rotation direction of the supplying means and the developer conveying direction are the same. For this reason, the developer is prevented from being blocked by the supply unit at the contact portion, and the stagnation of the developer is suppressed, so that the developer can be stably conveyed.

Further, the present invention is an image forming apparatus provided with the above-mentioned developing device.

[0020]

Embodiments of the present invention will be described. An embodiment of a developing device and an image forming apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of a configuration of an image forming apparatus to which an embodiment is applied. FIG.
FIG. 1 is a schematic diagram of a configuration of a developing device according to a first embodiment. FIG. 3 is a schematic diagram illustrating a configuration of the toner conveying member of the developing device according to the first embodiment. FIG. 4 is a waveform diagram illustrating an example of a voltage waveform applied to the toner conveying member according to the first embodiment. FIG. 5 is a schematic diagram illustrating a configuration of the toner conveying member of the developing device according to the first embodiment. FIG. 6 is a schematic diagram of another example of the developing device of the first embodiment. FIG. 7 shows the second embodiment.
FIG. 2 is a schematic diagram of a configuration of a developing device. FIG. 8 is an explanatory diagram of a contact portion between the toner conveying member and the supply member described in the second embodiment.

In order to explain the developing device of the present invention, an example of an image forming apparatus to which the developing device of the present invention is applied will be described. As shown in FIG. The image forming apparatus includes a charging member 3, an exposure member 4, a developing device 1, a transfer member 5, a cleaning member 6, a charge removing member 7, and a fixing member 8. The charging member 3, the exposure member 4, the developing device 1, the transfer member 5, the cleaning member 6, and the charge removing member 7 are arranged around the cylindrical photoreceptor 2 in this order. Of course, other members may be arranged. Further, between the photoreceptor 2 and the transfer member 5, a paper transport path through which the paper as the recording medium 9 is transported is arranged. A fixing member 8 is disposed on the downstream side of the photoconductor 2 when viewed from the conveyance direction of the paper conveyance path.

In the electrophotographic process, an original image or an electrostatic latent image corresponding to data from a host computer is formed on a photosensitive member 2 as an image carrier, and the electrostatic latent image is visualized by a developing device 1. The image is transferred onto a recording medium 9 such as a PPC sheet to form an image.

As shown in FIG. 1, the photoreceptor 2
A photoconductive layer 22 is formed thereon, and is rotatable from the charging member 3 according to the arrangement order of the above members. First, the surface of the photoconductor 2 is charged by the charging member 3 until it reaches a predetermined potential. The surface of the photoconductor charged to a predetermined potential reaches the position of the exposure member 4 by rotation of the photoconductor 2 (rotation direction 2a). The exposure member 4 is a writing unit, and writes an image on the surface of the photoconductor charged by light such as a laser based on image information. As a result, an electrostatic latent image is formed on the photoconductor 2. The surface of the photoconductor on which the electrostatic latent image is formed reaches the position of the developing device 1 by the rotation of the photoconductor 2.

The developing device 1 develops the electrostatic latent image on the surface of the photoreceptor as a toner image with a developer such as toner 17 conveyed on the toner conveying member (developer conveying means) 11. The surface of the photoconductor carrying the toner image reaches the position of the transfer member 5 by the rotation of the photoconductor 2. The transfer member 5 transfers the toner image on the photoreceptor surface onto a recording medium 9 such as a sheet. The toner image transferred from the photoconductor 2 onto the recording medium 9 is fixed on the paper by the fixing member 8.

After the toner image has been transferred, the surface of the photoreceptor
The rotation of the photoconductor 2 reaches the position of the cleaning member 6. The cleaning member 6 removes toner and paper dust remaining on the photoconductor surface. The photosensitive member surface cleaned by the cleaning member 6 is the photosensitive member 2
Reaches the position of the charge removing member 7 by the rotation of. The charge removing member 7 removes a potential remaining on the surface of the photoconductor. One image formation is completed by a series of operations described above.

As the photoreceptor 2, for example, a metal drum such as aluminum is used as a base material 21 and a photoconductive layer such as amorphous silicon (a-Si), selenium (Se), or an organic optical semiconductor (OPC) is formed on the outer peripheral surface thereof. There is a configuration in which 22 is formed in a thin film shape, but it is not particularly limited.

Examples of the charging member 3 include a corona charger composed of a charged wire such as a tungsten wire, a metal shield plate and a grid plate, a charging roller and a charging brush, but are not particularly limited. is not.

The exposing member 4 includes, for example, a semiconductor laser and a light emitting diode, but is not particularly limited.

Examples of the transfer member 5 include a corona transfer device, a transfer roller, and a transfer brush, but are not particularly limited.

The cleaning member 6 includes, for example, a cleaning blade, but is not particularly limited.

The charge removing member 7 includes, for example, a charge removing lamp, but is not particularly limited.

In FIG. 1, since a fixed interval is provided between the toner conveying member 11 and the photosensitive member 2, in this embodiment, the electrostatic latent image on the photosensitive member surface is not contacted. Although the configuration is such that development is performed, the present invention is not limited to this, and a configuration in which the toner transport member 11 is brought into contact with the surface of the photoconductor to perform contact development may be employed.

Embodiment 1 will be described. As shown in FIG. 2, the developing device 1 according to the present embodiment includes a toner conveying member (developer conveying unit) 11, a support member 12, a supply member 13, a recovery member 14, a light irradiation member 15, , Casing 16 and toner mixing means 18. The toner transport member (developer transport means) 11, the support member 12, the supply member 13, the recovery member 14, and the light irradiation member 15 will be described later. The casing 16 is composed of a toner (developer) 17
Is housed inside. The toner mixing means 18
The mixing paddle (MX paddle) is used in the present embodiment to mix and stir the toner 17 contained in the casing, and rotates in the rotation direction 18a.

The toner conveying member 11 has a belt shape so as to form a substantially flat surface facing the developing area 2b of the photosensitive member 2. In FIG. 2, a belt-shaped toner conveying member 11 is shown, but the shape of the toner conveying member 11 is not limited to this, and may be, for example, a semicircular shape. The toner conveying member 11 is shown in FIG.
The developing device 1 is arranged so as to be slightly inclined with respect to the vertical direction and substantially parallel to the tangential direction of the developing region 2b on the surface of the photoconductor. Further, a support member 12 for holding the toner conveying member 11 is provided on the surface opposite to the surface for conveying the toner 17 so that the belt-shaped toner conveying member 11 can maintain the above arrangement. Further, a photoconductive layer 111 is provided in a region including a contact portion of the toner conveying member 11 with the supply member 13,
The light irradiating member (light irradiating means) 15 for irradiating light to the region serving as the photoconductive layer 111 is a support member 1.
2 is provided inside.

The lower end portion (upstream side) of the toner conveying member 11
Is provided with a supply member (supply means) 13 for supplying the toner conveyed on the toner conveying member surface. On the other hand, a collecting member 14 for collecting the toner on the surface of the toner conveying member is provided at an upper end (downstream side) of the toner conveying member 11. Further, a multi-phase AC power supply 19a and a developing bias power supply 19b are connected to the toner conveying member 11 in series. Both the supply member 13 and the recovery member 14 are rotatably in contact with the surface of the belt-shaped toner conveying member 11.

The supply member 13 is for supplying the toner 17 contained in the casing 16 to the toner conveying member 11, and the material is not particularly limited. For example, silicone, urethane, EPD
Solid rubber such as M (ethylene-propylene-diene-methylene copolymer), foamed rubber, and the like.
In addition, conductivity may be imparted by adding carbon black or an ionic conductive agent (voltage can also be applied).
The function of charging the toner 17 to the supply member 13 may be added by setting the contact pressure between the supply member 13 and the toner transport member 11 and the voltage value applied to the supply member 13 to appropriate values. Alternatively, for example, a thin blade (the same material as that of the supply member 13 can be used) may be provided in a stage preceding the supply member 13 to charge the toner 17.

The collecting member 14 is for collecting the toner not contributing to the development of the electrostatic latent image on the photoreceptor 2 and returning it to the inside of the developing device 1. The material is not particularly limited. The same member as the supply member 13 can be used.

The support member 12 is for holding the belt-shaped toner conveying member 11 in a state of facing the developing area 2b of the photoconductor 2, and its configuration is not particularly limited. For example, polycarbonate and acrylic resin can be used.

As will be described later, the light irradiating member 15 can irradiate the photoconductive layer 111 of the toner conveying member 11 with light so that the charged area can be neutralized. Is not particularly limited as long as it is, for example, an LED (Light Emitting Dio
de) is preferably used.

The toner conveying member 11 conveys the toner 17 by an electric field curtain effect. As shown in FIG. 3, a traveling wave generating electrode 113 for generating an electric field curtain effect is provided in an insulating layer (base material) 114. However, a plurality of sets are buried sequentially and continuously with one set as a plurality. These electrodes 113 are connected to a multi-phase AC power supply 19 for toner conveyance.
a and a developing bias DC power supply 19b, an electric field curtain is generated in a direction parallel to the surface of the toner conveying member 11 by applying a multi-phase AC voltage. Is transported.

A specific example of the toner conveying member 11 is as follows.
For example, the base material 114: polyimide (thickness 25 μm),
The traveling wave generating electrode 113: copper (18 μm in thickness), the surface protective layer 112: polyimide (25 μm in thickness), and the like. In addition, the traveling wave generating electrode 113
A microelectrode having a width of 40 μm to 130 μm,
0 dpi (dot per inch) to 300 dpi, that is, about 2
They are arranged parallel to each other with a pitch of 54 μm to 85 μm.

In the present embodiment, four minute electrodes
Are set as one set. For each set of electrodes, for example, FIG.
Although a four-phase alternating voltage having a voltage waveform (having a phase shift) as shown in (1) is applied to form a traveling wave electric field on the traveling wave generating electrode, the invention is not particularly limited to this.
Three micro-electrodes may be applied as a set of three micro-electrodes. Further, as shown in FIG. 4, it is preferable that a bias voltage (developing bias) is applied so that a developing electric field is formed between the photoconductor 2 and the toner conveying member 11. This will be described later.

The voltage waveform to be applied may be a sine wave or a trapezoidal wave, and the voltage value range is preferably about 10 V to 1 kV, and the frequency range is 100 Hz to 1 kV.
00 kHz is preferably used. However, these voltage values and frequencies may be set to appropriate values depending on the shape of the traveling wave generating electrode 113, the conveying speed of the toner 17, the material used for the toner 17, and the like, and are not particularly limited.

In this embodiment, as shown in FIG. 2 and FIG. 5, the photoconductive layer 111 is provided in a certain area of the toner conveying member 11 including at least a contact portion with the supply member 13. 2 and 5, the photoconductive layer 111 is provided in a part of the surface protection layer 112 near the nip portion (the portion where the supply member is in contact).

In the conventional configuration (having no photoconductive layer),
When the preliminary charging means (supplying member) rotatably contacts the surface of the toner conveying member, not only the developer conveyed on the surface but also the toner conveying member is charged. When the toner conveying member is charged in this way, a traveling wave electric field sufficient to convey the toner in the area is not formed, and the possibility of obstructing the conveyance of the toner by the traveling wave is increased, and the toner is stabilized. There was a possibility that the transfer would be hindered.

On the other hand, in the present embodiment, since at least the vicinity of the nip where the supply member 13 and the toner conveying member 11 come into contact is formed by the photoconductive layer 111, the area of the photoconductive layer 111 is formed. The light irradiation member 15 is periodically
Irradiating the light, the charged toner conveying member 11 can be discharged. Therefore, the developer (toner) 1
7 can be transported more stably.

At this time, the photoconductive layer 111 is not particularly limited as long as it exhibits conductivity when irradiated with light. As a material used for the photoconductive layer 111, specifically, for example, an organic semiconductor including a carrier generation layer and a carrier transport layer, hydrogenated amorphous silicon, or the like is suitably used.

A specific example of the organic semiconductor will be described. First, the carrier generation layer may have a configuration in which a charge generation material is added to at least a binder resin. In addition, various additives such as a chemical sensitizer and an optical sensitizer may be added.

Examples of the charge generating material include bisazo compounds such as chlordian blue; polycyclic quinone compounds such as dibromoansansthrone; perylene compounds; quinacridone compounds; phthalocyanine compounds;
Azulenium salt compounds; and the like. Each of these materials may be used alone or in combination of two or more.

The binder resin for the carrier generation layer is not particularly limited. For example, polyvinyl butyral resin, polycarbonate resin, polyester resin, polyarylate resin, phenoxy resin, epoxy resin, polystyrene resin, polymethyl methacrylate resin, Examples include polyvinyl chloride resin and silicone resin.

The chemical sensitizer includes, for example, an electron accepting material, and the optical sensitizer includes various dyes. Although the electron accepting material is not particularly limited, for example, tetracyanoethylene, 7, 7, 8, 8
Cyano compounds such as tetracyanoquinodimethane; quinones such as anthraquinone and p-benzoquinone;
Examples include nitro compounds such as 4,7-trinitrofluorenone. The dye as the optical sensitizer is not particularly limited, but examples thereof include xanthene dyes; thiazine dyes; and triphenylmeta dyes.

Next, as the carrier transporting layer, a configuration in which a charge transporting material is added to at least the binder resin can be mentioned.

Examples of the charge transport material include high molecular compounds such as polyvinyl carbazole and polysilane; and low molecular compounds such as hydranzone compounds, oxadiazole compounds, stilbene compounds and triphenylmethane compounds.

The binder resin for the carrier transport layer is not particularly limited. For example, polycarbonate resin, polyester resin, phenoxy resin, epoxy resin, polystyrene resin, polymethyl methacrylate resin, polyvinyl chloride resin, silicone resin, etc. Is mentioned.

Next, hydrogenated amorphous silicon (a-
Si: H) will be described. Hydrogenated amorphous silicon is prepared by a conventional plasma-enhanced chemical vapor deposition method (plasma CVD).
Method: Intrinsic hydrogenated amorphous silicon created by Chemical Vapor Deposition or trace amount (several ppm to several pp)
m) Boron doped hydrogenated amorphous silicon to which boron (B) is added.

The volume resistivity of this hydrogenated amorphous silicon
The resistivity ρ is 10⁹Ω · cm or more 10 ¹¹Ω · cm or less
It is preferable, but not particularly limited.
The volume resistivity ρ is the base at the time of fabrication by the plasma CVD method.
Set the plate temperature, pressure, gas flow rate,
It can be adjusted by setting.

In the present embodiment, any of the above materials may be used for the photoconductive layer, but hydrogenated amorphous silicon is more preferable. Hydrogenated amorphous silicon is preferred because it has the advantages of relatively easily removing static electricity without disturbing the traveling wave electric field, exhibiting bipolar conductivity, having a high surface hardness and preventing abrasion of the surface protective layer, and the like. .

In the present embodiment, since the triboelectric charge generated by the contact between the supply member and the toner conveying member can be of both positive and negative electric charges, the electric conductivity of both polarities is higher than that of the material having only one polarity. If the material has the following formula, the charge of the toner conveying member can be reliably removed even if the charging polarity changes. That is, the photoconductive layer in the present embodiment is not limited to hydrogenated amorphous silicon, and it is preferable to use a material having ambipolar conductivity.

Further, it is preferable that the traveling wave generating electrodes arranged in the region where the photoconductive layer is provided are formed of transparent electrodes. Thus, when the light irradiation member irradiates the photoconductive layer with light, the light is not blocked by the electrodes. Therefore, the entire photoconductive layer can be uniformly irradiated with light to perform more uniform charge removal.

The transparent electrode is not particularly limited, but examples thereof include ITO (Indium Tin Oxide), tin oxide (SnO ₂ ), and indium oxide (In ₂ O ₃ ). The method for forming the transparent electrode is not particularly limited. For example, an electron beam evaporation method is preferably used.

In the configurations shown in FIGS. 2 and 5, the photoconductive layer is provided only at the nip between the supply member and the toner conveying member. However, the present embodiment is not limited to this. As shown in FIG. 6, a photoconductive layer 111 may be provided on the entire surface protective layer of the toner conveying member 11.

At this time, in order to irradiate the entire area of the toner conveying member with light, the light irradiating member 15 is rotated (rotational direction 15).
a) is preferably used. When rotating the light irradiation member 15, it is preferable to adjust the current value according to the distance between the light irradiation member 15 and the photoconductive layer 111 in order to make the light irradiation intensity the same. Thereby, static elimination can be performed more reliably.

In the present embodiment, at the time of irradiating the light with the light irradiating member 15, the bias voltage (predetermined voltage) is applied to at least one of the supply member 13 and the traveling wave generating electrode 113 of the toner conveying member 11. DC voltage)
Is preferably applied.

For example, in the present embodiment, the toner conveying member 11 includes four sets of microelectrodes to form a set, and apply a four-phase voltage waveform as shown in FIG. , And a traveling wave electric field is formed on the traveling wave generating electrode. Further, as shown in FIG. 4, a developing electric field is formed between the photosensitive member 2 and the toner conveying member 11. It is preferable that the developing bias voltage (predetermined DC voltage) is applied as described above (at this time, the supply member 13 is connected to the ground potential or the developing bias power source 1).
9b is applied.) As a result, the electric field formed in the photoconductive layer 111 can be increased, so that the charged toner conveying member 11 can be more quickly discharged.

Conversely, when a voltage is applied to the supply member 13,
Each pair of electrodes of the toner conveying member 11 may be applied with a ground potential or a voltage having a polarity opposite to the voltage applied to the supply member 13.

The timing of light irradiation by the light irradiation member 15 in the present embodiment is not particularly limited, but a more preferable timing is each time one development operation is completed. That is, completion of one development operation coincides with the timing at which the image forming apparatus including the development device 1 of the present embodiment completes one image formation operation. Therefore, each time an image forming operation is performed,
Since the charge on the toner conveying member 11 is removed, the undesired charged state of the toner conveying member 11 is canceled every time the image forming operation is performed. therefore,
The toner can always be stably transported every time an image forming operation is performed, and the quality of the formed image can be further improved.

Embodiment 2 will be described. In the present embodiment, the rotation direction 13a of the supply member and the toner conveyance direction 11
By setting a to the same direction (forward direction), the toner 17 can be transported more smoothly. As shown in FIG. 7, the developing device 1 according to the present embodiment has substantially the same configuration except that the photoconductive layer and the light irradiation member according to the first embodiment are not provided.

Here, a description will be given of supplying toner to the toner conveying member by rotating while the supplying member is in contact with the surface of the belt-shaped toner conveying member. FIG.
As shown in FIG. 10, when the rotation direction of the supply member is opposite to the toner conveyance direction at the nip portion 13b, toner accumulation occurs at the exit side of the nip portion.
The occurrence of such toner accumulation indicates that the toner is not smoothly transported, and furthermore, this toner accumulation also acts as a barrier to toner transport, so that smooth toner transport becomes more difficult. .

Therefore, in the present embodiment, the rotation direction of the supply member at the nip portion, that is, the rotation direction of the supply member 13 on the surface in contact with the toner conveyance member 11 is set to the forward direction with respect to the toner conveyance direction. That is, the direction is the same. As a result, as shown in FIG. 8, the toner is prevented from being blocked by the supply member at the nip portion, and the developer is prevented from staying, so that the developer can be stably conveyed.

As the supply member 13, the same one as in the first embodiment is used, but the rotation speed at this time is preferably several mm / s to several tens mm / s. Further, the contact pressure (nip pressure) between the surface of the toner conveying member 11 and the supply member 13 in the nip portion is preferably several gf / mm. The rotation speed and contact pressure of the supply member 13 are set to appropriate values according to the material and toner conveyance speed used for the supply member 13 and the toner conveyance member 11 (the toner conveyance member 11 is charged as described in the first embodiment). May be set so that toner accumulation does not occur. By setting the supply member in this manner, the occurrence of toner accumulation can be effectively avoided.

Further, the configuration in the second embodiment, that is, the configuration in which the rotation direction of the supply member is set in the same direction as the toner transport direction, is the same as that in the first embodiment, that is, the photoconductive layer is provided in the nip portion, The present invention can be applied to a configuration in which charge is removed by irradiation. As a result, the formation of the traveling wave is not hindered by the configuration of the first embodiment, and the toner is transported more smoothly. Further, since the toner is not accumulated by the supply member, the toner is further transported more smoothly. become. Therefore, in the developing device according to the present invention, it is highly preferable that not only one of the first and second embodiments but also both configurations are employed. Further, as an image forming apparatus having a developing device, an image forming apparatus other than an electrophotographic process, for example, an image forming apparatus of another system such as an ion flow system and a toner jet system can be similarly applied.

[0072]

According to the present invention, when a mechanism (electric field curtain) for transporting a developer using a traveling wave electric field is used, problems that hinder the transport of the developer can be solved.
It is possible to obtain a developing device capable of smoothly and reliably transporting the developer and a high-quality image forming apparatus including the developing device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a configuration of an image forming apparatus to which an embodiment is applied.

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

FIG. 3 is a schematic cross-sectional view of a toner conveying member of the developing device according to the first embodiment.

FIG. 4 is a waveform diagram illustrating an example of a voltage waveform applied to a toner conveying member according to the first embodiment.

FIG. 5 is a schematic front view of a toner conveying member of the developing device according to the first embodiment.

FIG. 6 is a schematic view of another example of the developing device according to the first embodiment.

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

FIG. 8 is an explanatory diagram of a contact portion between a toner conveying member and a supply member described in a second embodiment.

FIG. 9 is a schematic front view of a toner conveying member of the developing device in which toner accumulation occurs.

FIG. 10 is an explanatory diagram of toner accumulation at a contact portion between a toner conveying member and a supply member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 developing device 11 toner transport member 11a toner transport direction 111 photoconductive layer 112 surface protection layer 113 traveling wave generating electrode 114 base material 12 support member 13 supply member 13a rotation direction 13b nip portion 14 recovery member 15 light irradiation member 16 casing 17 toner Reference Signs List 18 MX paddle 19a Multi-phase AC power supply 19b Development bias DC power supply 2 Photoconductor 2a Rotation direction 2b Development area 21 Base material 22 Photoconductive layer 3 Charging member 4 Exposure member 5 Transfer member 6 Cleaning member 7 Static elimination member 8 Fixing member 9 Recording medium

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tasuke Uemura 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Kiyoshi Toizumi 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Shiro Narukawa 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2H077 AA37 AB03 AC04 AC13 AC16 AD00 AD07 AD13 AD31 AD36 CA02 CA10 EA15 EA16

Claims (7)

[Claims] 1. A developer transporting means for transporting a developer by forming a traveling-wave electric field by a polyphase voltage applied to a plurality of electrodes arranged at predetermined intervals in a base material, and the developer And a substantially cylindrical supply means for rotatably contacting the surface of the transport means and supplying the developer to the developer transport means, and the developer transport means transfers the electrostatic latent image to the surface thereof. A developing device arranged in a developing area opposed to the image carrier that carries the light, a light irradiating unit that irradiates light, and the developer conveying unit includes a light irradiating unit that irradiates the light with the light. A developing device comprising a conductive layer at least in a region including a contact portion with a supply unit. 2. The developing device according to claim 1, wherein said photoconductive layer is formed of a material exhibiting ambipolar conductivity. 3. The developing device according to claim 1, wherein the electrodes arranged in a region where the photoconductive layer is provided in the developer conveying means are transparent electrodes. 4. The method according to claim 1, wherein a predetermined DC voltage is applied to at least one of a plurality of electrodes in the supply unit and the developer conveying unit when the light is irradiated by the light irradiation unit. The developing device according to claim 1. 5. The developing device according to claim 1, wherein the light irradiation by the light irradiation unit is performed each time one developing operation is completed. 6. An electrostatic latent image comprising developer transport means for transporting a developer by forming a traveling-wave electric field by a polyphase voltage applied to a plurality of electrodes arranged at predetermined intervals. In the development area facing the image carrier carrying the surface thereof,
In the developing device in which the developer conveying unit is disposed, the developer conveying unit rotatably contacts the surface of the developer conveying unit, and
A supply unit having a substantially cylindrical shape for supplying the developer conveyed on the surface; and a rotation direction of the supply unit on the surface is a forward direction with respect to a conveyance direction of the developer. A developing device. 7. An image forming apparatus comprising the developing device according to claim 1.