JPH0895373A - Control electrode member for electrophotographic developing device and developing method - Google Patents

Abstract

PURPOSE: To accurately and stably set a plate-like control electrode member in developing space formed by an image forming body and a developer carrying body opposed to the image forming body and to obtain a sufficient developing accelerating effect by forming the control electrode member of an insulating member having a dielectric constant in 1MHz larger than a specified value and an electrode member provided on the insulating member. CONSTITUTION: This control electrode member is constituted of the insulating member 45a inserted and set between the developer carrying body 41 and the image forming body 1 on an upstream side from a developing area or in the developer carrying direction of the developer carrying body 41 and the electrode member 45b provided on the insulating member 45a. The dielectric constant in 1MHz of the insulating member 45a is set to exceed 3.5 at 25 deg.C. A part of the plate-like control electrode member 45a constituted of the insulating member 45a and the electrode member 45b, for example, a part along the axial direction of a developing roller being the developer carrying body 41 is held in the shaft direction by a holding member 45c, whereby the control electrode member is accurately arranged in the developing space formed by the image forming body 1 and the developer carrying body 41 opposed to the image forming body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic developing apparatus, and more particularly, to transferring a developer or toner from a developer carrier to an electrostatic latent image on an image forming body, thereby developing the electrostatic latent image. The present invention relates to a control electrode member effectively used in an apparatus and a developing method.

[0002]

2. Description of the Related Art The powder developing method is classified into a contact type developing method in which a developer layer is in contact with an image forming body and a non-contact type developing method in which both are not in contact with each other. In any of the developing methods, the powder developer is transported to the vicinity of the image forming body as uniformly as possible with a layer thickness determined by a developer transporting body such as a developing roller and attached to the electrostatic latent image.

On the other hand, a developing method is known in which a powder developer is electrically ejected from a developer carrier to develop a latent image on an image forming body. In particular, a method in which a developer is vibrated by an AC electric field is widely used as an improved technique of the classical powder cloud developing method. The following publicly known examples belong to this category and have been proposed as a feature of inserting a control electrode into the developing space between the developer transport body and the image forming body. It is possible to increase the amount of development and to develop faithfully to the latent image by adopting the developing method using the control electrode, and such an effect is obtained especially in the electrophotographic method using the toner having a fine particle diameter. It's big.

(1) Japanese Unexamined Patent Publication No. 56-27158: A plurality of parallel electrode wires are stretched between an electrophotographic photosensitive member as an image forming body and a developer carrier, and the polarities of adjacent electrode wires are reversed. Development method in which an alternating voltage is applied to each electrode wire to cause the developer to fly.

(2) JP-A-57-198470: A wire grid is provided between the latent image holding surface and the toner holding surface to form a grid.
A developing method in which a direct current and / or an alternating current or an odd voltage is applied between the toner holding surfaces.

(3) Japanese Patent Laid-Open No. 3-131878: A developing method in which an electrode plate is arranged in the developing area and an alternating electric field is applied to the electrode plate to disperse and fly the toner.

(4) Japanese Patent Laid-Open No. 4-115264: A multicolor developing method using a plurality of developing devices according to the above-mentioned application technique.

However, with the techniques (1) and (2), it is difficult to accurately arrange the wires in the narrow developing space. In the techniques (3) and (4), plate electrodes are used instead of the wires. Although the placement accuracy is improved by using it, the electrode is installed over the upstream side and the downstream side in the developer transport direction with respect to the closest position of the image forming body and the developer transport body, Since the side electrode has a function of pushing back the developer toward the upstream side, for example, when the plate-like electrode is cantilevered on the upstream side and the upstream side of the developer transport body is blocked by the electrode with respect to the image forming body. Causes the amount of developer conveyed to the downstream side of the electrode, where substantial development occurs, to hinder effective development, and when the downstream side is supported by a cantilever to block the downstream side of the developer conveyance body, development is performed. The developer is the developer carrier-between the image forming bodies or the developer carrier- Has the disadvantage that results in scattering beyond the space between the poles.

In order to solve the above-mentioned drawbacks of the known technique and to carry out effective development, in (5) Japanese Patent Application No. 5-303377, the developer transport direction of the developer transport member is upstream from the development region. On the other hand, a control electrode member has been proposed which is composed of an insulating member which is placed on the side of the developer carrier so as to be in contact with or closest to the developer and an electrode member which is provided on the downstream side of the closest position.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a method of flying a powder developer by installing a plate-shaped control electrode member in the developing area among the above-mentioned known techniques.

As described above, the adoption of the plate-shaped control electrode member realizes highly accurate electrode installation.

The plate-shaped control electrode member has a higher rigidity than the linear or other shape electrode member, and a part thereof, for example, a portion along the axial direction of the developing roller, which is a developer transporting body, is arranged along the axial direction. If it is held by the holding member, it can be accurately arranged in the developing space formed by the image forming body and the developer conveying body facing the image forming body.

In particular, the method of placing the control electrode member in pressure contact with the developer on the developer transport body allows easy installation of the electrode with high accuracy. That is, if such a control electrode member is inserted and installed in the developing space so as to press and contact the developer on the developer carrying body, it can be accurately arranged in the developing space.

Further, the method of placing such a control electrode member in pressure contact with the image forming body also enables highly accurate placement of the electrode. That is, if such a control electrode member is inserted and installed in the developing space formed by the image forming body and the developer transporting body facing the image forming body so as to be in pressure contact with the image forming body, the control electrode member can be accurately arranged in the developing space. Can be done.

Since such a plate-shaped electrode member is installed in the vicinity of the developing device, especially in the developing space, it is difficult to use a thick plate-shaped electrode member with a large and complicated holding member. It is practical to carry out a thin plate-shaped body by supporting a part thereof. For example, a practical method is to carry out the control electrode member, which is a plate-like elastic body, by cantilevering the upstream end with respect to the developer transport direction. Especially usually 1mm
In order to insert the control electrode member with a margin in the thickness of the developing area, that is, the thickness in the vicinity of the closest position between the image forming body and the developer transport body, the control electrode is provided between the developer transport body and the control electrode member. It is preferable to set the thickness of the control electrode member to be as thin as possible in order to sufficiently increase the electric field formed in the second step and effectively cause the developer to peel and fly from the developer carrier. On the other hand, however, the thin control electrode member is inevitably low in rigidity, and it is difficult to realize stable installation by supporting only one end, for example.

A control electrode member made of a resin member reinforced with an inorganic fiber or an organic fiber having a large tensile strength and a large bending elastic modulus is effective to some extent for such a purpose, and its stable installation is required. Can be expected. However, even in that case, if a sufficiently thick member is used to achieve sufficiently stable installation, a voltage drop occurs due to this thick insulating member between the developer on the developer transport body and the electrode member, and the developer is peeled off. The flight cannot be caused effectively enough.

[Objects and Advantages of the Invention] In the present invention, the plate-shaped control electrode member is installed in the developing space to electrically fly the powder developer from the developer carrier to develop the latent image on the image forming body. On how to do.

An object of the present invention is to provide both a precise and stable installation of a plate-shaped control electrode member in a developing space formed by an image forming body and a developer carrying body facing the image forming body and a sufficient development promoting effect. It is in.

That is, stable installation and stable operation of the control electrode member, that is, realization of uniform high image density and low background density (which appears as a color mixing phenomenon in the case of non-contact superposition development) over a long period of time. Is a specific purpose.

Specifically, the dielectric constant at 1 MHz is larger than a certain value, and if necessary, an insulating member made of a resin or other material reinforced with inorganic fibers or organic fibers and an electrode member provided on the insulating member. An excellent control electrode member whose electrode member meets these purposes and a developing method using the same are provided. According to such a control electrode member and the developing method using the same, the developer supplied to the developing area can be highly efficiently ejected and adhered to the latent image on the surface of the image forming body. Therefore, it is possible to stably obtain a clear image in which the developer is not attached to a portion where the developer is not desired to be attached.

[0021]

According to the invention of claim 1 of the present application, the toner is inserted between the developer transport body and the image forming body on the upstream side of the developing region or the developer transport direction of the developer transport body. Control electrode member for a developing device, which comprises an insulating member installed on the insulating member and an electrode member provided on the insulating member, and the dielectric constant of the insulating member at 1 MHz exceeds 3.5 at 25 ° C. Therefore, the above object is achieved thereby.

According to the invention of claim 6 of the present application, a control electrode member comprising an insulating member having a dielectric constant at 1 MHz of more than 3.5 at 25 ° C. and an electrode member provided on the insulating member is used as a developer carrier. Development in which one end is fixedly held on the upstream side of the developing area with respect to the developer conveying direction and is inserted between the developer conveying body and the image forming body toward the downstream side so that the other end is located in the developing area. A method for achieving the above object.

The insulating member constituting the control electrode member of the present invention is made of resin reinforced with inorganic fiber or organic fiber, various ceramics and the like as required.

The resins used in the present invention are various thermoplastic resins or thermosetting resins.

When a thermoplastic resin is used, it can be manufactured by an inexpensive production means having excellent mass productivity such as injection molding or extrusion molding as described later. The good storage stability of the raw materials also contributes to the high productivity. Further, the toughness of the obtained member is superior to the case where a thermosetting resin is used, and the variety of thermoplastic resins is abundant, so the degree of freedom in material design is high. Another feature is that it can be remelted and shaped again, so that it can be used for recycling.

As the thermoplastic resin used in the present invention, various crystalline or amorphous polymer substances belonging to the category of so-called general-purpose resins, engineering plastics and super engineering plastics can be used.

Thermoplastic resins classified as general-purpose plastics include polyethylene, polypropylene (above crystalline), polyvinyl chloride, polystyrene, ABS resin, A
Homopolymers or copolymers such as S resin and methacrylic resin (above amorphous) can be used.

Although thermoplastic resins classified as general-purpose plastics can be applied to the present invention, thermoplastic resins classified as engineering plastics or super engineering plastics are more advantageously used. Thermoplastic resins classified as so-called engineering plastics or super engineering plastics include ultra-high molecular weight polyethylene, poly-4-methylpentene-1, nylon (nylon-6, nylon-6).
6, nylon-11, nylon-12, etc.), polyacetal, polybutylene terephthalate, polyethylene terephthalate, paraoxybenzoyl group-containing wholly aromatic polyester, polyphenylene sulfide, polyether ether ketone, polyamide imide (more crystalline), polyphenylene ether, polycarbonate , Polyarylate (polyester of 2-hydric phenol and aromatic dicarboxylic acid), polysulfone, polyethersulfone, polyetherimide (above amorphous) and the like can be used.

There is also a thermoplastic resin that exhibits physical properties comparable to engineering plastics while having a chemical structure to be classified as general-purpose plastics. Examples thereof include syndiotactic polystyrene called metallocene polymerized polymer, metallocene polymerized polyethylene, isotactic polypropylene, and syndiotactic polypropylene. These are excellent in mechanical properties (rigidity, impact resistance), heat resistance, etc. as compared with ordinary resins having the same chemical structure, and are advantageously used in the present invention.

Fluorine resin is another substance which is classified as a thermoplastic engineering plastic and which is advantageously used in the present invention. The fluororesin is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene
-Hexafluoropropylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene-ethylene copolymer, chlorotrifluoroethylene-ethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride and the like.

When a thermosetting resin is applied to the present invention, it is usually necessary to use a member manufacturing means different from the case where a thermoplastic resin is used. However, in these special production means other than injection molding and extrusion molding, it is possible to use relatively long inorganic fibers, organic fibers or processed products thereof as a reinforcing material, and it is one of the objects of the development of the present invention. It is advantageous to realize a highly rigid control electrode member for accurately and stably installing the plate-shaped control electrode in the space.

As the thermosetting resin, unsaturated polyester resin, epoxy resin, vinyl ester resin, phenol resin, thermosetting polyimide resin, thermosetting polyamide-imide or the like can be used.

As the unsaturated polyester resin, an orthophthalic acid resin, an isophthalic acid resin, a terephthalic acid resin, a bisphenol resin, a propylene glycol-maleic acid resin, dicyclopentadiene or a derivative thereof is introduced into the unsaturated polyester composition. And low molecular weight, or low styrene volatile resin with a film forming wax compound added, and thermoplastic resin (polyvinyl acetate resin, styrene-butadiene copolymer, polystyrene, saturated polyester, etc.) with low shrinkability resin,
Reactive type such as bromination of unsaturated polyester directly with Br ₂ or copolymerization with het acid, dibromoneopentyl glycol, halides such as chlorinated paraffin, tetrabromobisphenol and antimony trioxide, phosphorus compounds Addition-type flame-retardant resin that uses combination or aluminum hydroxide as an additive, tough resin (high strength, high elastic modulus, high elongation) that is hybridized with polyurethane or silicone, or IPN, etc. is there.

Bisphenol A as the epoxy resin
Type, novolac phenol type, bisphenol F type, brominated bisphenol A type glycidyl ether type epoxy resin, glycidyl amine type, glycidyl ester type, cycloaliphatic type, and heterocyclic epoxy type special epoxy resin.

The vinyl ester resin is usually a product obtained by dissolving an oligomer obtained by ring-opening addition reaction of an epoxy resin and an unsaturated monobasic acid such as methacrylic acid in a monomer such as styrene. In addition, there is also a special type that has a vinyl group at the terminal or side chain of the molecule and contains a vinyl monomer. Vinyl ester resins of glycidyl ether epoxy resins include bisphenol resins, novolac resins, brominated bisphenol resins, and the like, and special vinyl ester resins include vinyl ester urethane resins, vinyl isocyanurate, and side chain vinyl ester resins.

The phenol resin is obtained by polycondensing phenols and formaldehydes as raw materials. There are resol type and novolak type.

Examples of the thermosetting polyimide resin include maleic acid type polyimides such as polymaleimidoamine, polyaminobismaleimide, bismaleimide.o, o'-diallylbisphenol-A resin, bismaleimide.triazine resin, and nadic acid-modified polyimide. , And acetylene-terminated polyimide.

As the ceramics used in the present invention,
Al ₂ O ₃ (alumina), MgO / Al ₂ O ₃ (spinel), 3Al ₂ O ₃
· 2Si ₂ O _{3 (mullite), Al 2 O 3 -ZrO 2} ( zirconia), S
i ₃ N ₄ , SiC, ZrO ₂ , Al ₂ TiO ₂ , PSZ, cordierite,
Tricalcium phosphate, hydroxyapatite, tricalcium phosphate-zirconia, hydroxyapatite-zirconia, mullite-zirconia, SiC-TiC (conductive), Si-CN (usually Y ₂ O ₃ -Al ₂ O as a sintering aid) ₃ ), Al ₂ O ₃ -La ₂ O ₃ , Al ₂ O ₃ -T
Examples include various oxide-based, non-oxide-based, and mixed-system inorganic substances such as iO ₂ (Na) and TiC-ZrO ₂ .

The insulating member used in the present invention is optionally reinforced with inorganic fibers. As the inorganic fibers used in this case, whiskers (needle-shaped crystals), polycrystals, amorphous short fibers, continuous fibers, or those obtained by subjecting these to various processes can be used.

Whiskers have very few transitions and the strength is close to the ideal value of the inorganic crystal. Further, the resin reinforced with whiskers can be molded by a very general molding method such as injection molding, which is advantageous in this respect. Examples of such whiskers include hexagonal α-SiC whiskers, cubic β-SiC whiskers, α-Si ₃ N ₄ whiskers, K ₂ O ・ 6TiO ₂ (potassium hexatitanate) whiskers, graphite whiskers, β-Si _6-Z Al _Z O _Z N _8-Z (Sialon)
Whiskers and ZrO ₂ whiskers can be used.

The inorganic short fibers are fibers having a finite length that is not a single crystal and usually have a length of 1 mm or more and 10 cm or less. As such inorganic short fibers, for example, various glass fibers, carbon fibers, alumina short fibers, alumina / silica short fibers, ZrO ₂ short fibers, boron nitride short fibers and the like can be used.

The inorganic continuous fibers are fibers having a length equal to or larger than the size of the member and are roughly classified into two according to the difference in diameter. One is used as a monofilament with a diameter of 100 to 200 μm, and there is also one with boron or SiC grown on the surface by CVD. The other is a bundle with a diameter of 20 μm or less, which is used as a multifilament. The latter is superior when it is used after being processed into a woven fabric or when a member having a complicated shape is formed. If continuous fibers are used, it is generally possible to form a member having a high content of fibers with a controlled fiber arrangement, and it is possible to greatly improve the strength and rigidity of the member. However, it is necessary to use special means for forming, and secondary plastic working is impossible. Such inorganic continuous fibers include various glass fibers, fused silica, tungsten core wire continuous boron fiber (monofilament), tungsten core wire SiC continuous fiber (monofilament), tungsten core wire B ₄ C continuous fiber (monofilament), tungsten core wire silicon carbide- Boron continuous fiber (monofilament), carbon fiber core wire SiC continuous fiber (monofilament), fused silica core wire boron continuous fiber (monofilament), BN continuous fiber, SiC continuous fiber, Si-Ti-CO (B) continuous fiber (tyranno fiber) Alumina fiber, PAN carbon fiber, pitch carbon fiber, Z containing SiO ₂ , B ₂ O ₃
It is possible to use rO ₂ long fibers, various metal continuous fibers such as tungsten continuous fibers, molybdenum continuous fibers, steel continuous fibers, beryllium continuous fibers, super heat resistant nickel alloy (Rene 41) continuous fibers, and stainless steel continuous fibers.

Of the inorganic fibers, glass fibers that can be used at a particularly low cost are E-glass fibers, C-glass fibers, A-glass fibers, S-glass fibers, M-glass fibers,
There are fused quartz and the like.

The glass fiber is often surface-treated with an organic chromium complex compound, an organic silane compound or the like by a conventional method.

The insulating member used in the present invention is optionally reinforced with organic fibers. As the organic fibers used in this case, fibers made of a wide range of organic polymer substances can be used. Usually, a heat-stretched polymer or a polymer having a rigid polymer chain is often used to increase the number of fully extended polymer chains in the unit cross-sectional area. The aramid fiber is advantageously used for improving the elastic modulus of the member reinforced by this. Further, aramid pulp processed into fine fibers can be used as well. Liquid crystal polymer fibers have high impact absorption and are advantageously used for improving impact resistance, durability and abrasion resistance. In particular, if a high elastic modulus grade that has recently been obtained is used, it can be advantageously used for improving the elastic modulus.
Ultra-high molecular weight polyethylene fibers are weak against heat and require careful molding temperature, but they are advantageously used for improving the elastic modulus and impact resistance. The hybrid fabric of ultra high molecular weight polyethylene and carbon fiber is advantageously used by complementing the adhesiveness of polyethylene fiber and the impact resistance of carbon fiber. It is also possible to use polyvinyl alcohol fibers, particularly high-performance grade polyvinyl alcohol fibers (vinylon fibers), heterocyclic aromatic polymer fibers such as polyparaphenylene benzobisthiazole, acrylic fibers, and polyester fibers.

These inorganic fibers and organic fibers are used in various forms. For example, glass fibers are strands,
Used in the form of roving, yarn, continuous strand mat, scrim cloth, chopped strand mat, surface mat, roving cloth, glass cloth (woven yarn), chopped strand, chipped strand, glass powder, milled fiber, etc. To be

Carbon fibers are also similar to glass fibers such as strands, tows (corresponding to roving of glass fibers), yarns, cloths (woven with tows, woven with yarns), chopped strands and unidirectional materials. Used in the form. The same applies to other fibers.

The reinforcing fibers used in the present invention should be used in such a ratio that the rigidity of the molded article becomes the highest, but since the member of the present invention requires a smooth surface, these are The fibers should not be exposed and should be used within limits that give a smooth molding surface. Such an optimum usage ratio is generally high if reinforced fibers are woven,
In addition, the higher the affinity between the resin matrix and the fibers, the higher the affinity. Based on this fact, the fibers used in the present invention are 2 to 80% by weight, and most preferably 5% by weight, based on the whole molding.
To 60% by weight.

The method of manufacturing the insulating member constituting the control electrode member of the present invention differs depending on the types of resin and ceramics constituting them and, if reinforcing fibers are used, the type and form thereof.

When the thermoplastic resin is reinforced without using reinforcing fibers, or is reinforced with inorganic fibers or organic fibers which have a short length or are not given a secondary form by weaving, etc., the thermoplastic resin is used. The molding method generally used for molding is used. When the fiber is reinforced, a material called FRTP pellet can be used as a raw material. That is, unmelted or already melted thermoplastic resin and short fiber reinforcement and, if necessary, additives such as fillers are melt-kneaded in a kneading extruder and extruded in a strand form, cooled, or cut in a molten state. It is also possible to use a pelletized product by adhering and impregnating a molten resin or the like while passing a roving-like bundle of long fibers through the die and cutting this to a predetermined length. The proportion of the reinforcing material used is 2 to 80% by weight, but preferably 5 to 60% by weight, and this range can be widely adjusted in FRTP manufactured by using a bundle of long fibers. For molding with such a thermoplastic resin, in addition to injection molding, extrusion molding, blow molding,
Injection blow molding, compression molding, rotational molding, cast molding (casting), transfer molding (transfer molding), powder processing, solvent coating, machining, etc. can be used. It is also possible to use a special molding method called RIM.For example, in the case of nylon, a lactam containing reinforcing fiber, catalyst and activator is injected into the mold as needed, and a molded product is formed by anionic polymerization. Can be obtained.

Since polytetrafluoroethylene has a high melt viscosity, general melt processing cannot be applied. Compression molding,
Molding is performed by ram extrusion molding, paste extrusion molding, dispersion method, or the like.

The insulating member which constitutes the control electrode member made of thermosetting resin may be manufactured by injection molding or transfer molding similar to the thermoplastic resin.

As a means for carrying out the manufacture of the insulating member constituting the control electrode member made of a thermosetting resin reinforced with an inorganic fiber or an organic fiber in the simplest manner, a so-called SM is used.
There is a method of using C, BMC, or an intermediate product called prepreg.

SMC (sheet molding compound) is a thermosetting resin in the form corresponding to roving or chopped strand mat of glass fiber of inorganic fiber or organic fiber and, if necessary, thickener, filler, release agent. It is a sheet-shaped molding material in which a resin compound mixed with a pigment or the like is impregnated, both surfaces are covered with a non-adhesive sheet such as polyethylene, and then the resin compound is thickened with a thickener to make it non-adhesive. At the time of molding, a necessary amount is cut off, a sheet of polyethylene or the like is peeled off, the sheet is loaded into a mold and heated and pressed to cure. Since the resin used in preform molding and other molding methods is liquid but solid, it is easy to handle and advantageous in automating the molding. Since the reinforcing fiber and the resin compound flow together in the mold, a better molding surface than the preform molded product can be obtained.
Further, as compared with injection molding of BMC and the like, it is possible to obtain a molded product having excellent strength without breakage of reinforcing fibers up to the final molded product.

On the other hand, a premix which is a putty-like molding material produced by kneading a thermosetting resin, short reinforcing fibers, and if necessary, a filler, a pigment, a curing agent, etc., is particularly wavy or scratched. A BMC is a lump or preformed product that has a smooth surface and has excellent physical properties that prevent warping. Often, a thermoplastic resin is added to reduce shrinkage.

It is possible to integrally mold objects of complicated shape, the molding speed is high, and inserts, attachments, holes,
It has the feature that screws, ribs, bosses, etc. can be molded.

Further, heat is applied to a product in which reinforcing fibers that are longer than those of SMC are aligned, a product in which anisotropy of fiber orientation is eliminated by stacking multiple layers thereof, or a cloth in which reinforcing fibers are woven. A product obtained by impregnating a curable resin and, if necessary, a filler, a pigment and the like with a solvent, impregnating and drying the product, and a semi-cured product is called a prepreg, and a molded product can be obtained by press molding.

More general molding methods for thermosetting resins reinforced with inorganic fibers or organic fibers include hand lay-up method, spray-up method, mat or preform matched die method, premix method, filament winding method, addition method. The pressure reduction rubber bag method, the continuous pull-through method, etc. Since the insulating member constituting the control electrode member of the present invention has a relatively simple shape, the mat or preform matched die method, the premix method, the pressure / vacuum bag method, and the continuous pull-through method are particularly advantageous. The mat or preform matched die method uses male and female reinforced fiber mats such as chopped strand mats or reinforced fibers such as chopped strands shaped by preforming that are impregnated with a thermosetting resin (thermoplastic resin) binder. A molded product is obtained by pressing and heating in a mold. The premix method is compression molding using the above premix,
A molded product is obtained by transfer molding (transfer molding) or injection molding. In the pressure / vacuum bag method, a glass fiber base material such as prepreg is placed on either male or female mold and PVA is placed on top of it.
It is a method of covering with a film such as etc. and applying pressure from the outside, or drawing the inside vacuum to form. The continuous pull-through method is a method in which rovings, tows and the like are aligned, dipped in a resin or a mixture thereof, molded into a predetermined cross-sectional shape through a die, and then cured in a heating furnace.

In this molding process, inorganic fibers,
Various additives may be used in addition to the organic fiber, the thermoplastic resin, and the thermosetting resin. Particularly when a thermosetting resin is used, a curing agent and a curing accelerator are often used. An organic peroxide, an azo compound or the like is used as the curing agent. In some cases, a sensitizer for curing ultraviolet light or visible light may be used. As the accelerator, amine-based or metal naphthenic acid salts are used for the purpose of causing curing at room temperature.

The use of the filler sometimes has the effect of improving various physical properties such as mechanical strength, thermal conductivity, abrasion resistance and flame retardancy of the molded product depending on the particle shape and surface effect. Calcium carbonate, alumina, talc, diatomaceous earth, clay, kaolin, mica, barium sulfate, gypsum, silica gel (aerosil), glass balloon, shirasu balloon and the like may be used alone or in combination.

When a colorant is used, it is general to use a paste color in which a pigment is kneaded in advance, but a powder such as carbon black or titanium white may be used in some cases.

As the release agent, either an external release agent or an internal release agent or both are used. Specifically, stearic acid,
Examples thereof include zinc stearate, magnesium stearate, calcium stearate, aluminum distearate, soybean lecithin, various other waxes, poval, silicones and the like.

Other additives used include thickeners and thixotropic agents.

In the method for producing ceramics or fiber-reinforced ceramics, if necessary, an aqueous medium is used to mechanically mix the raw materials, and the raw material mixture is prepared by stirring or coprecipitation, and the aqueous medium is used. If there is, separate it by filtration. The obtained mixture or the like is formed into a thin plate and hot pressed. Further, cold isostatic pressing (CIP) molding is performed, and if necessary, atmospheric pressure sintering is performed in an atmosphere of an inert gas such as Ar. Sometimes a hot isostatic press is used. Inorganic fibers when fiber-reinforced ceramics,
Only metal fibers are used.

In order to provide an electrode member on the control electrode member in order to manufacture the control electrode member from the insulating member thus molded, when the insulating member is made of resin, an electrode material such as electrolytic copper foil or the like is used as described above. It is most efficient to provide the insulating member by molding, for example, press molding, and at the same time laminating and using an adhesive as needed, but a method of adhering the electrode material to the insulating member after molding. Any of the methods of heating and fusing can be used. Further, in order to install the electrode member only on a very limited part of the control electrode member, it is possible to install the electrode only on that part, but after the electrode is installed on a wide part, the so-called etching method is used. A method of removing the required portion is advantageous. Furthermore, it is also possible to install the electrode member by printing or applying a conductive ink or a conductive paint on the insulating member. Of course, the electrode member may be installed not only on the surface of the control electrode member but also inside thereof. In that case, when the insulating member is made of resin, the electrode material is molded at the same time as the insulating member is laminated by using an adhesive as needed, or as described above. The insulating member having the electrode member installed on the surface thereof is formed by stacking the insulating member on the insulating member having the electrode member installed on the surface and molding the insulating member by using an adhesive as required. It can be installed by gluing an insulating member that is molded separately on top of it.

The same applies when the insulating member is made of ceramics. When the ceramic itself is electrically conductive, it is possible to install the electrode member after the surface of the ceramic is covered with an insulating resin, ceramics or the like to obtain an insulating member.

A specific mode of mounting the control electrode member for the developing device manufactured as described above in the electrophotographic developing device will be described below.

[0068]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a modified U-BIX 9028 (manufactured by Konica Corp.) used as the image forming apparatus of this embodiment. Reference numeral 1 denotes a photosensitive drum, which is an image forming body in which a photoconductor is applied to an aluminum tube, and rotates clockwise.

2 is a scorotron charger, which is a charging means, and 3
Is an image writing device using a laser beam as an image exposing means, 4A, 4B, 4C and 4D are developing devices each containing a developer of a specific color, 5 is a transfer device, 6 is a cleaning device, and 8 is an image reading device. is there.

Each of the developing devices 4A, 4B, 4C, 4D
Respectively contain yellow (Y), magenta (M), cyan (C), and black (K) developers, and a developer transport body having a predetermined gap with the photosensitive drum 1, respectively.
41, the latent image on the photosensitive drum 1 is visualized by a non-contact reversal development method. The developer transport body 41 rotates counterclockwise. Incidentally, the developing devices 4A, 4B, 4C, 4D
Details of will be described later.

The transfer belt 5b of the transfer device 5 contains the transfer discharger 5a and is kept at a position separated from the surface of the photosensitive drum 1 while an image is formed on the photosensitive drum 1. After the image formation on the drum 1 is completed, the surface of the photoconductor drum 1 is contacted as shown in the figure only when transferring to the transfer material.

The cleaning blade 6a and the toner carrying roller 6b of the cleaning device 6 are kept at a position separated from the surface of the photoconductor drum 1 during image formation, and as shown in the figure only when cleaning after image transfer, It is pressed against the surface of 1. A color image is formed by the image forming apparatus as follows.

The halogen lamp 80 of the image reading device 8 illuminates the original document placed on the document table 7, and the reflected light is reflected by the first mirror 81, the second mirror 82, and the third mirror 83, and the lens 84 and the dichroic. Blue through the prism 85,
The color is separated into red and green, blue is read by the blue CCD 86, red is read by the red CCD 87, and green is read by the green CCD 88. CCD
The analog signal from is converted into a digital signal by an A / D converter (not shown) and image-processed.

When the image-processed digital signal is input to the image writing device 3, laser light emitted from a semiconductor laser which is a writing light source (not shown) passes through a collimator lens and a cylindrical lens (not shown) to drive a drive motor. The light is deflected by the rotating polygon mirror 34 rotated by 31, the optical path is bent by the mirror 35 through the fθ lens 32 and the cylindrical lens 33, and a uniform charge is applied in advance by the scorotron charger 2 as a charging means. It is projected onto the peripheral surface of the photoconductor drum 1 to scan and form the main bright line. An electrostatic latent image corresponding to the first color is formed on the peripheral surface of the photosensitive drum 1 by the main scanning by the deflection of the laser beam and the sub-scanning by the rotation of the photosensitive drum 1.

This electrostatic latent image is subjected to reversal development by the developing device 4A loaded with a two-component developer consisting of yellow (Y) toner and a magnetic carrier to form a toner image. The photoconductor drum 1 is separated from the photoconductor drum 1 while holding the toner image on the surface thereof.
After passing under the cleaning device 6, the next image forming cycle is started.

The photoconductor drum 1 is recharged by the scorotron charger 2, and then a digital signal corresponding to the second color is input to the image writing device 3 and the same as in the case of the first color signal described above. Then, an electrostatic latent image is formed on the surface of the photosensitive drum 1. The electrostatic latent image is magenta (M)
Reversal development is carried out by the developing device 4B loaded with a two-component developer consisting of the toner and the magnetic carrier. The magenta (M) toner image is also formed on the previously formed yellow (Y) toner image.

Reference numeral 4C is a developing device having a two-component developer composed of cyan (C) toner and a magnetic carrier, and similarly forms a cyan (C) toner image on the surface of the photosensitive drum 1. Further, 4D is a developing device having a two-component developer composed of black toner and a magnetic carrier, and similarly forms a black toner image on the surface of the photosensitive drum 1.

The multicolor toner image thus formed on the peripheral surface of the photosensitive drum 1 is transferred to the transfer discharger 5a of the transfer device 5.
Is applied to the transfer material sent from the paper feeding device 9 by applying a high voltage having a polarity opposite to that of the toner.

That is, the transfer material stored in the paper feeding device 9 is fed to the transfer device 5 at the same timing as the image formation on the photosensitive drum 1 by discharging the uppermost one sheet by the rotation of the paper feeding roller 10. To be done.

The transfer material which has received the image transfer is separated from the photosensitive drum 1 along the transfer belt 5b of the transfer device 5. The transfer material, which is separated from the transfer belt 5b by a sheet discharging device (not shown), is conveyed to the fixing device 12 by the conveying belt 11, the image is fused by the fixing roller 12a of the fixing device 12, and then the discharge roller 12b is removed. After that, the paper is ejected to the paper ejection tray 13.

On the other hand, the photosensitive drum 1 which has been transferred to the transfer material is further rotated to press the blade 6a of the cleaning device 6 and the toner carrying roller 6b into contact with each other to remove the residual toner, and then the blade. 6a is separated, and shortly thereafter, the toner carrying roller 6b is separated and a new image forming process is started.

Next, the developing devices 4A to 4D described above will be described in detail. The developing devices 4A to 4D have the same configuration, and these are collectively denoted by reference numeral 4.

FIG. 2 is a schematic sectional view of the developing device 4 used in the present invention. Reference numeral 41 in FIG. 2 is a JIS 10-point average roughness display (JIS-B0610), which is a rotatable developer carrier made of stainless steel or the like having a rough surface of 1 to 2 μm, and 43 agitates the developer 42. Stirrer to even out the ingredients,
44 is a supply roller that supplies the developer 42 to the developer transport body 41, 46 is a developer transport amount regulating member that regulates the thickness of the developer layer on the developer transport body 41, and 47 is the developer transport body
It is a scraper for stripping off the developer 42 on the 41. Reference numeral 45 denotes a plate-shaped member (control electrode member) having an electrode member, which includes an insulating member 45a and an electrode member 45b. The details of the plate member 45 having the electrode member will be described later.

A DC bias power source E1 is used for the developer carrier 41.
A bias voltage obtained by superimposing the AC voltage on the DC voltage is applied from the AC bias power source E2 through the protection resistor R1.
Further, a DC bias voltage is applied to the electrode member 45b by a DC bias power source E3 via a protection resistor R2.

FIG. 3 is a sectional view showing an example of arrangement of control electrode members in the developing device.

As a most general method of mounting the control electrode member 45 in the electrophotographic developing apparatus, a plate-shaped control electrode member 45 including an insulating member 45a and an electrode member 45b is partially
For example, if a portion of the developer transport body 41 along the axial direction of the developing roller is held by the holding member 45c along the axial direction, a developing space formed by the image forming body 1 and the developer transport body 41 opposed thereto It is possible to arrange this inside with high precision. A fluctuating electric field is applied between the control electrode member 45 and the developer transport body 41.

FIG. 4 is a sectional view showing another arrangement example of the control electrode member 45.

A control electrode member is provided on the developer on the developer transport body 41.
The method of installing by contacting 45b with pressure makes it possible to easily install an electrode with high accuracy. That is, if such a control electrode member 45 is inserted and installed in the developing space A so as to press and contact the developer 42 on the developer transport body 41, it can be accurately arranged in the developing space A. The method of placing the control electrode member 45 in pressure contact with the developer on the developer transport body 41 is disclosed in the above-mentioned prior arts, Japanese Patent Application Laid-Open No. 3-131878 and Japanese Patent Application No. 5-303377. That is, as shown in FIG. 4, it is used as the control electrode member 45 which is arranged so as to come into contact with the developer on the developer transport body 41 and have its tip end located in the developing area A.

FIG. 5 is a cross-sectional view showing still another arrangement example of the control electrode member 45. That is, as disclosed in Japanese Patent Application No. 5-303377, the insulating member 45a is brought into contact with the developer transport body 41 upstream of the developing area A, and the electrode member 45b contacts the insulating member 45a. It is used as a control electrode member installed only on the downstream side in the developer transport direction from the contact position. In this case, the length of the electrode member 45b in the developer transport direction is preferably 0.01 to 2 mm. In either case, a fluctuating electric field is applied between the control electrode member 45 and the developer transport body 41.

FIG. 6 is a sectional view showing another example of the arrangement of the control electrode member 45.

That is, the control electrode member 45 of the present invention may be installed in contact with the image forming body 1 contrary to the above known example.
Control electrode member 45 including insulating member 45a and electrode member 45b
Then, it is desirable that the insulating member 45a is in contact with the image forming body 1. In this case also, a fluctuating electric field is applied between the control electrode member 45 and the developer transport body 41.

Closing the developing region A or the downstream side of the developer transporting body 41 with respect to the developer transporting direction with the control electrode member 45 significantly reduces the developing efficiency, or the developer 42 transports the developer transporting body. The undesired result of scattering over the space between 41 and the image forming body 1 or between the developer transport body 41 and the control electrode member 45 is brought about. Therefore, when the control electrode member 45 is generally installed in the developing space, it is necessary to insert the control electrode member 45 from the upstream side with respect to the developer carrying direction of the developer carrying body 41. When the developer 42 on the body 41 is placed in pressure contact with the developer 42, the developer 42 on the developer transport body 41 is in pressure contact with the developer area A or upstream of the developer transport direction. Need to be installed. In addition, even when the image forming member 1 is installed in pressure contact with the image forming member 1, it is also not preferable to close the developing area A or the downstream side of the developer conveying member 41 in the developer conveying direction. In either case, the control electrode member 45 is connected to the developer carrier 41.
One end is fixedly held on the upstream side of the developing area A with respect to the developer carrying direction, and is inserted between the developer carrying body 41 and the image forming body 1 toward the downstream side so that the other end is located in the developing area A. It is convenient to install it.

In the present invention, the electrode member 45b is installed on a surface other than the surface of the control electrode member 45 on the side of the developer transport body 41 or inside thereof. This is because it is convenient to prevent the electrode member 45b from being damaged by being exposed to the relatively uneven thickness of the developer 42, especially the magnetic developer.

7A to 7D are cross-sectional views showing various embodiments of the control electrode member 45 in which the electrode member 45b is provided on the upper surface of the insulating member 45a, and FIGS. 8] is a cross-sectional view showing an example in which an electrode member 45b is embedded inside an insulating member 45a. 7J to 7O are cross-sectional views showing an example in which the electrode member 45b is provided at or near the tip of the insulating member 45a. FIG. 7P is a cross-sectional view showing an example in which the electrode member 45b is arranged on the upper surface and the tip of the insulating member 45a.

In the above-mentioned Japanese Patent Application No. 5-303377, the insulating member 45
a is brought into contact with the developer transport body 41 upstream of the developing area A, and the electrode member 45b is provided only on the downstream side in the developer transport direction from the contact position of the insulating member 45a. This is intended to prevent the developer 42 from backflowing and scattering to the upstream side in the developer conveying direction from the closest position. This is the case where all the installation methods of the control electrode member 45 are used, that is, the simple insertion into the developing space A, the pressing installation to the developer 42 on the developer transport body 41, and the pressing installation to the image forming body 1. Also, the electrode member 45b is installed only on the downstream side of the developer transporting direction of the developer transporting body 41 with respect to the closest position Q of the insulating member 45a to the developer transporting body 41. Is more preferable. Considering the thickness of the developing area A, the length measured in the developer conveying direction, and the required rigidity, the size of the control electrode member 45 is 20 except for the portion fixed to the holding member 45c.
˜500 μm, and the length measured in the developer conveying direction is preferably 5 to 50 mm.

The free end of the control electrode member 45 needs to be in the developing area A, but it goes without saying that the installation method in which most of the developing area A is closed by the control electrode member 45 is not preferable. Normally, the free end is located upstream of the closest position Q between the image forming body 1 and the developer transport body 41.

The fluctuating electric field applied between the control electrode member 45 and the developer transport body 41 causes the developer 42 to exceed the control electrode and effectively develop a latent image on the image forming body 1 by an AC power source. E2
Is preferably applied so as to be connected to the developer transport body 41 side. Of course, a DC bias electric field may be appropriately applied between the developer transport body 41, the control electrode member 45, and the image forming body 1. FIG. 8 shows an example of the electrical configuration of the present invention.

FIG. 9 is a cross-sectional view showing a structural example of a developing device using the control electrode member of the present invention. That is, the control electrode member 45 of the present invention, as disclosed in JP-A-3-131878,
It may be used in a developing device configuration that also serves as the developer transport amount regulating member 46 or the developer charging member. In these cases, the control electrode member 45 is placed in contact with the developer 42 on the developer transport body 41, and in the latter case, the developer 42 is the control electrode member.
Charge is imparted by frictional charging with 45.

Further, the control electrode member 45 of the present invention may be used in a developing device structure which also serves as a developer leveling member. Also in this case, the control electrode member 45 is installed in contact with the developer 42 on the developer transport body 41. The developer leveling member has already been disclosed in JP-B-63-16736, JP-A-4-36383 and JP-A-5-289522.

FIG. 10 is a sectional view showing another structural example of the developing device using the control electrode member of the present invention. That is, Japanese Patent Publication Sho 63
No. 16736, it is used as an elastic regulating plate whose abdominal surface is in pressure contact with the developer transport body 41 in order to regulate the layer thickness of the developer 42 supplied to the developer transport body 41.

FIG. 11 is a sectional view showing still another example of the structure of the developing device using the control electrode member of the present invention. That is, as disclosed in Japanese Patent Laid-Open No. 4-36383, a magnetic pole in a non-contact two-component developing device for applying an oscillating electric field to a developing region sandwiched by two magnetic poles having different polarities in the developer transport body 41. It may be installed as a pressing member to press the two-component developer at the position.

FIG. 12 is a sectional view showing still another example of the structure of the developing device using the control electrode member of the present invention. That is, as disclosed in Japanese Patent Laid-Open No. 5-289522, a non-magnetic material installed so as to come into contact with the developer upstream of a magnetic pole installed in the developer transport body 41 so as to face the development area A. It can be used as a developer leveling means.

FIG. 13 is a sectional view showing still another example of the structure of the developing device using the control electrode member of the present invention. That is, the developer layer is provided at a predetermined distance from the surface of the developer transport body 41, and the developer layer on the surface of the developer transport body 41 is regulated to a thickness to contact the surface of the image forming body 1 installed so as to face the developer layer. In the developing device 4 having the developer carrying amount regulating member 46, the developing device 4 is installed so as to come into contact with the developer 42 upstream of the magnetic pole installed in the developer carrying body 41 so as to face the developing area A. It can be used as a non-magnetic developer leveling means.

FIG. 14 is a sectional view showing still another example of the structure of a developing device using the control electrode member of the present invention. That is, the development is installed at a predetermined distance from the surface of the developer transport body 41, and the developer layer on the surface of the developer transport body 41 is regulated to a thickness to contact the surface of the image forming body installed so as to face the development. In the developing device 4 having the developer carrying amount controlling means, the developing area A is provided in the developer carrying body 41 also as the developer carrying amount controlling means.
It can be used as a non-magnetic developer leveling means installed so as to come into contact with the developer 42 upstream of the magnetic pole installed so as to face the developer.

FIG. 15 is a sectional view showing still another example of the structure of the developing device using the control electrode member of the present invention. That is, in the developing device 4 having the developer regulating means installed at a predetermined distance from the surface of the developer transport body 41, the developer transport body is
A predetermined thickness that makes contact with the developer 42 upstream of the magnetic pole installed in the area 41 so as to face the developing area A and makes the developer layer on the developer transport body 41 non-contact with the surface of the image forming body 1. It can be used as a non-magnetic developer leveling means to be installed.

FIG. 16 is a sectional view showing still another example of the structure of the developing device using the control electrode member of the present invention. That is, it is installed so as to come into contact with the developer 42 between the magnetic pole installed in the developer transport body 41 so as to face the development area A and between another magnetic pole having the same polarity as the magnetic pole. It can be used as a developer leveling means.

FIG. 17 is a sectional view showing still another example of the structure of the developing device using the control electrode member of the present invention. That is, it is installed with a predetermined gap from the surface of the developer transport body 41 so as to face another magnetic pole having the same polarity upstream of the magnetic pole installed in the developer transport body 41 so as to face the developing area A. , Can be used as a developer leveling unit that is used together with a developer transport amount regulating unit that regulates the passing amount of the developer 42.

The developer 42 used here may be a two-component developer comprising toner and magnetic particles, or may be a magnetic or non-magnetic one-component developer.

The control electrode member 45 of the present invention is the developer carrier 41.
When it is installed in pressure contact with the upper developer 42 or the image forming body 1, it is 5000 g / c in the direction orthogonal to the developer carrying direction of the developer carrying body 41 or the rotating direction of the image forming body 1.
It is pressed with a force of m, preferably 2000 g / cm or less. The control electrode member 45 of the present invention uses the holding member 45c to develop the developing area A.
Placed inside. When the portion not held by the holding member 45c is installed so as to be positioned in the developing area A as a free end, the control electrode member 45 must support its own weight. Further, when the control electrode member 45 is installed in pressure contact with the developer 42 or the image forming body 1, the control electrode member 45 must support this pressing force. Such continuous application of force causes the control electrode member 45 to be permanently deformed and, as a result, the pressing force to be reduced, or the relative distance between the developer transport body 41, the control electrode member 45, and the image forming body 1. There is a risk that the performance of the developing device 4 may be changed by changing the physical positional relationship, or that the developer transport amount, the developer charge amount, and the developer leveling effect may be changed. In order to avoid such permanent deformation and to stably install the control electrode member 45, the insulating member 45a constituting the control electrode member 45 should be designed to be as thick as possible within a range where the control electrode member 45 can be installed in the developing area A. Good,
It is possible to use a material having a rigidity as high as possible, such as a material reinforced with an inorganic fiber or an organic fiber.

However, the commonly used insulating member 45a having a thickness of 20 to 500 μm is the developer transport body 41 and the control electrode member.
It has the effect of reducing the electric field based on the AC voltage applied between the developer and the developer 45 supplied to the developing area A with high efficiency toward the latent image on the image forming body 1 and adheres thereto. If a high voltage is applied to compensate for such an electric field reduction effect, it is possible to stabilize a clear image in which the developer 42 does not adhere to the background portion where the developer 42 is not desired to adhere. Hard to get.

The present invention will be specifically described below with reference to examples, but of course the present invention is not limited to these examples.

Example 1 A nylon 6 resin containing 30 wt% of glass fiber is compression molded to obtain an insulating member having a thickness of 350 μm. The dielectric constant of this member at 1 MHz was 4.0 at 25 ° C. A 12 μm-thick electrolytic copper foil was adhered to the surface of this product with a 5 μm-thick epoxy adhesive, and a control electrode member having a 1 mm-wide electrolytic copper foil left only at the tip portion was obtained by etching.

FIG. 18A shows the image forming body 1 and the developer carrying body 41.
And FIG. 18B is a partially enlarged sectional view in the vicinity of the developing area A. FIG.

In FIGS. 18A and 18B, θ ₁ is the angle formed by the developer transport amount regulating member 46 with the magnetic pole closest to the rotation axis O of the developing roller, and θ ₂ is the transport of the image forming body 1 and the developer. Body 4
The closest contact point R between 1 and the rotary shaft O of the developing roller forms an angle with the upstream magnetic pole in the developer transporting direction of the developer transporting body 41, and θ ₃ is the rotary contact point O of the developing roller. The angle formed with the downstream magnetic pole is shown. Also,
l ₁ is the free length of the cantilever-supported control electrode member 45, l ₂ is the intersection M of the extension line of the holding member 45 c and the developer transport body 41.
And the horizontal distance between the closest contact point R between the image forming body 1 and the developer transport body 41. d is the control electrode member 45 from the closest contact point R.
The horizontal distance to the front end of the developer carrier 41 is denoted by r.

U-BIX 9028 type color copying machine (Konica Corporation)
(Made by the manufacturer) is changed to a doctor blade having a gap of 125 μm with the developer conveying roller, and the control electrode member 45 is mounted, and each dimensional value shown in FIG. 18 is r = 10.
mm, l ₁ = 9 mm, l ₂ = 4 mm, d = 0.5 mm, θ ₁ = 0 °, θ
₂ = 30 °, θ ₃ = 30 °, and the surface potential of the photoreceptor on the non-exposed area is-
850V, exposure section photoconductor surface potential is -50V, control electrode DC potential is -750V, DC bias applied to developer carrier (developing roller) 41 is -750V, AC bias frequency is 8kHz, and its voltage is 0.85kV. Set to _0-p . Developer 42 is U-
BIX9028 is the developer carrier σ ₁₀₀₀ of normal 18emu
/ G was used as it was except that it was changed to 25emu / g.

When the exposed portion of the photosensitive member was black-developed, it was 1.25.
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Also,
When the exposed portion of the photoreceptor was developed with yellow and then the unexposed portion was developed with black, the black toner adhesion amount was 40 particles / mm ^2, which was small.

The image quality did not deteriorate even after 50,000 continuous copies.

Comparative Example 1 Nylon 6-6 resin is compression molded to obtain an insulating member having a thickness of 350 μm. 1MH of this member
The dielectric constant at z was 3.4 at 25 ° C. A 12 μm thick electrolytic copper foil is adhered to the surface of this with an epoxy adhesive of 5 μm thickness, and a control electrode member 45 having a 1 mm wide electrolytic copper foil left only at the tip portion is obtained by etching.

U-BIX9028 type color copier (Konica Corporation)
(Manufactured), the developer transport amount regulating member 46 is changed to a doctor blade having a gap of 125 μm with the developer transport body 41, and this control electrode member 45 is mounted, and each dimensional value shown in FIG. 18 is r = 10 mm,
l ₁ = 9 mm, l ₂ = 4 mm, d = 0.5 mm, θ ₁ = 0 °, θ ₂ = 3
0 °, θ ₃ = 30 °, and unexposed area photoconductor surface potential is -850
V, exposure surface photoconductor surface potential is -50V, control electrode DC potential is -750V, applied DC bias to the developer carrier (developing roller) 41 is -750V, applied AC bias frequency is 8kHz.
z, and its voltage was set to 0.85 kV _0-p . Developer 42 is U-BIX9
028 is the developer carrier σ ₁₀₀₀ of the normal 18emu / g
Was used as it was, except that it was changed to 25 emu / g.

The black toner attached to the exposed portion of the photoconductor is 0.
It was 90 mg / cm ² , and a sufficient image density was not obtained.

When the applied AC bias frequency was increased to 8 kHz and the voltage was increased to 0.98 kV _0-p , the black toner development adhesion amount was improved to 1.23 mg / cm ² , and the exposed portion of the photoconductor was yellow-developed under these conditions. When the unexposed area was black-developed thereafter, the amount of black toner adhered was 100 / mm ² and violent color mixing was visually observed.

With the applied AC bias set to 8 kHz and 0.85 kV _0-p , the thickness of the insulating member was reduced to 300 μm, and the respective dimensional values shown in FIG. 18 were r = 10 mm, l ₁ = 7 mm, l ₂ = 3.4 mm,
When d = 0.5 mm, θ ₁ = 0 °, θ ₂ = 30 °, and θ ₃ = 30 °, good image density and low color mixture were initially obtained, but the developer layer was formed by continuous copying of 11,000 copies. Insufficient pressure was applied to the part, and violent color mixing occurred corresponding to this part.

Example 2 A polyacetal resin containing 25 wt% of glass fiber was compression molded to obtain an insulating member having a thickness of 300 μm. The dielectric constant of this member at 1 MHz was 3.9 at 25 ° C. A 12 μm-thick electrolytic copper foil is adhered to the surface of this product with a 5 μm-thick epoxy adhesive, and a control electrode member 45 is obtained by retreating from the tip by 500 μm by etching to leave a 500 μm-wide electrolytic copper foil.

U-BIX9028 type color copying machine (Konica Corporation)
The developer layer regulating member 46 of Ltd.) was changed to a doctor blade gap 175μm between the developer conveying member 41 equipped with the control electrode member 45, each dimension shown in FIG. 18 r = 10mm, l ₁
= 6 mm, l ₂ = 4 mm, d = 1.0 mm, θ ₁ = 0 °, θ ₂ = 0
And θ ₃ = 45 °, the surface potential of the non-exposed photoconductor is -850.
V, exposure unit photoconductor surface potential of -50 V, control electrode DC potential of -750 V, applied DC bias to developer carrier (developing roller) 41 of -750 V, applied AC bias frequency of 12 kH
z, and its voltage was set to 0.40 kV _0-p . The developer is U-BIX902
8 was used as it was, except that the developer carrier σ ₁₀₀₀ was changed from the usual 18 emu / g to 25 emu / g.

When the exposed portion of the photoconductor was developed in black, 1.30
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. When the exposed portion of the photoreceptor was developed with yellow and then the unexposed portion was developed with black, the amount of black toner deposited was 35 particles / mm ^2, which was small.

The image quality did not deteriorate even after 50,000 continuous copies.

Comparative Example 2 A PBT resin is compression-molded to obtain an insulating member having a thickness of 300 μm. The dielectric constant of this member at 1 MHz was 3.1 at 25 ° C. A 12 μm thick electrolytic copper foil is attached to the surface of this product with a 5 μm thick epoxy adhesive, and it is moved back by 500 μm from the tip by etching and the width
A control electrode member having an electrolytic copper foil as an electrode member of 500 μm is obtained.

U-BIX9028 type color copier (Konica Corporation)
The developer layer regulating member 46 of Ltd.) was changed to a doctor blade gap 175μm between the developer conveying member 41 equipped with the control electrode member 45, each dimension shown in FIG. 18 r = 10mm, l ₁
= 6 mm, l ₂ = 4 mm, d = 1.0 mm, θ ₁ = 0 °, θ ₂ = 0
And θ ₃ = 45 °, the surface potential of the non-exposed photoconductor is -850.
V, exposure unit photoconductor surface potential of -50 V, control electrode DC potential of -750 V, applied DC bias to developer carrier (developing roller) 41 of -750 V, applied AC bias frequency of 12 kH
z, and its voltage was set to 0.40 kV _0-p . Developer 42 is U-BIX9
028 is the developer carrier σ ₁₀₀₀ of the normal 18emu / g
Was used as it was, except that it was changed to 25 emu / g.

When the exposed portion of the photoconductor was developed in black, the amount of toner attached was 0.73 mg / cm ² , and a sufficient image density could not be obtained.

When the applied AC bias frequency was increased to 12 kHz and the voltage was increased to 0.50 kV _0-p , the adhered amount of black toner was improved to 1.28 mg / cm ² , and the exposed portion of the photoconductor was yellow-developed under these conditions. When the non-exposed portion was black-developed after that, the black toner adhesion amount was 96 / mm ² and violent color mixing was visually observed.

The thickness of the insulating member was reduced to 240 μm while the applied AC bias was set to 12 kHz and 0.40 kV _0-p , and the respective dimensional values shown in FIG. 18 were r = 10 mm, l ₁ = 5 mm, l ₂ = 3.8mm,
When d = 1.0 mm, θ ₁ = 0 °, θ ₂ = 0 °, and θ ₃ = 45 °, good image density and low color mixture were initially obtained, but the developer layer was formed by continuous copying of 5000 copies. Insufficient pressure was applied to the part, and violent color mixing occurred corresponding to this part.

Example 3 A layer of plain-woven glass cloth made of E-glass was treated with γ-aminopropyltrimethoxysilane, and 6 phr of dicyandiamide was added as a curing agent so that the weight of the molded article would be 50%. Epoxy equivalent 4
It is impregnated with 80 bisphenol A type epoxy resin varnish (using methyl ethyl ketone solvent), dried on two sheets of prepreg, and electrolytic copper foil with a thickness of 12 μm is layered on it.
/ Cm ² is press-molded to obtain a member having a thickness of 262 μm. The electrolytic copper foil electrode member having a width of 500 μm is left by etching, and the same prepreg is laminated again on the surface having the electrode member 45b and press-molded under the same conditions, followed by punching,
As shown in the cross-sectional view of FIG. 19, an electrolytic copper foil electrode member having a width of 500 μm, which is retracted from the tip by 500 μm, is provided on the lower surface, that is, at a position 250 μm from the pressing contact surface of the developer carrier 41 to the developer 42. A control electrode member 45 having a thickness of 375 μm is obtained. In FIG. 18, when an insulating member 45a having no electrolytic copper foil was similarly prepared and measured, the dielectric constant at 1 MHz was 4.8 at 25 ° C. U-BIX9028 type color copying machine (manufactured by Konica Corp.) was replaced with the developer transport amount regulating member 46 to a doctor blade having a gap of 100 μm with the developer transport roller 41, and this control electrode member 45 was mounted. Each dimension value shown in r = 10 mm, l
₁ = 6 mm, l ₂ = 4 mm, d = 1.0 mm, θ ₁ = 0 °, θ ₂ = 0
And θ ₃ = 60 °, the surface potential of the non-exposed photoconductor is -850.
V, exposure unit photoconductor surface potential -50V, control electrode DC potential -700V, applied DC bias to developer carrier (developing roller) 41 -750V, applied AC bias frequency 10kH
z, and its voltage was set to 0.35 kV _0-p .

As the developer 42, U-BIX 9028 was used as it was, except that the developer carrier σ ₁₀₀₀ was changed from the usual 18 emu / g to 25 emu / g.

When the exposed portion of the photosensitive member was black-developed, it was 1.33.
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Also,
When the exposed portion of the photoreceptor was developed with yellow and then the unexposed portion was developed with black, the amount of black toner deposited was 21 particles / mm ^2, which was extremely small.

There was no deterioration in image quality even after the continuous 50,000 copies.

Example 4 A varnish having a concentration of 50% by weight in which polyaminobismaleimide (Kerimid601-Rhone Poulenc) was dissolved in N-methylpyrrolidone was preliminarily treated with N-β-aminoethyl-γ-aminopropyltrimethoxysilane. A layer of plain woven glass cloth made of treated E-glass was impregnated so that the weight in the molded product would be 50%, and dried at 150 ° C for 15 minutes. Hold at 190 ° C. and 50 kg / cm ² for 2 hours and press-mold to obtain a member having a thickness of 312 μm. 20 from the tip by etching
Control electrode member that retracts 0 μm and leaves the electrode member with a width of 500 μm
Get 45. The dielectric constant of the part without the electrolytic copper foil was 4.6 at 25 ° C. at 1 MHz. The U-BIX9028 type color copying machine (manufactured by Konica Corp.) was replaced with the developer transport amount regulating member 46 to a doctor blade having a gap of 200 μm with the developer transport roller 41, and this control electrode member 45 was mounted. The respective dimension values shown in r = 10 mm, l ₁ = 6 mm, l ₂ = 4 mm, d = 0.5 mm, θ ₁ = 0
°, θ ₂ = 0 °, θ ₃ = 60 °, the non-exposed area photoconductor surface potential is -850 V, the exposed area photoconductor surface potential is -50 V, the control electrode DC potential is -800 V, and the developer carrier (development) Laura) 41
The applied DC bias was set to -750 V, the applied AC bias frequency was set to 10 kHz, and the voltage was set to 0.35 kV _0-p .

The developer 42 used was that of U-BIX 9028, except that the developer carrier σ ₁₀₀₀ was changed from the usual 18 emu / g to 25 emu / g.

When the exposed portion of the photosensitive member was black-developed, it was 1.33.
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Also,
When the exposed portion of the photosensitive member was developed with yellow and then the unexposed portion was developed with black, the adhered amount of black toner was 22 particles / mm ^2, which was extremely small.

There was no deterioration in image quality even after 50,000 continuous copies.

Comparative Example 3 Polybenzophenone tetracarboxylic acid imide (PI2080-Upjohn equivalent product, benzophenone tetracarboxylic acid / methylenedianiline / toluylenediamine condensate) is electrolyzed at 350 ° C. and 800 kg / cm ² to a thickness of 12 μm. A member with a thickness of 312 μm is obtained by stacking with a copper foil and press-molding. 200μm back from the tip by etching and 500μm
A control electrode member 45 having the width of the electrode member left is obtained. The dielectric constant of the part without the electrolytic copper foil was 3.3 at 25 ° C. at 1 MHz. The U-BIX9028 type color copier (made by Konica Co., Ltd.) is provided with a developer transport amount regulating member 46 and a gap 20 with the developer transport roller.
This control electrode member 45 was changed to a doctor blade of 0 μm.
Mounted, and the respective dimension values shown in Fig. 18 are r = 10 mm, l ₁ = 6 m
m, l ₂ = 4 mm, d = 0.5 mm, θ ₁ = 0 °, θ ₂ = 0 °, θ ₃
= 60 °, non-exposed area photoconductor surface potential is -850V, exposed area photoconductor surface potential is -50V, control electrode DC potential is -800V
V, the applied DC bias to the developer transport body (developing roller) 41 was set to -750 V, the applied AC bias frequency was set to 10 kHz, and the voltage was set to 0.35 kV _0-p .

The developer used was U-BIX 9028 as it was, except that the developer carrier σ ₁₀₀₀ was changed from 18 emu / g to 25 emu / g.

The black toner attached to the exposed portion of the photoconductor is 0.
It was 58 mg / cm ² , and a sufficient image density could not be obtained.

When the applied AC bias frequency was increased to 10 kHz and the voltage was increased to 0.49 kV _0-p , the toner adhesion amount on development was 1.3.
Although it was improved to 3 mg / cm ² , under this condition, when the exposed portion of the photoreceptor was developed with yellow, the unexposed portion was developed with black.
The amount of black toner deposited was 92 / mm ² , and violent color mixing was visually observed.

With the applied AC bias set to 10 kHz and 0.35 kV _0-p , the thickness of the insulating member was set to 210 μm, and the respective dimension values shown in FIG. 18 were r = 10 mm, l ₁ = 5 mm, l ₂ = 3.9 mm. , D =
When 0.5 mm, θ ₁ = 0 °, θ ₂ = 0 °, and θ ₃ = 60 °, good image density and low color mixture were initially obtained.
The continuous copying of 9,000 copies resulted in an insufficiently pressed portion of the developer layer, and violent color mixing occurred corresponding to this portion.

Example 5 A varnish having a concentration of 50% by weight in which polyaminobismaleimide (Kerimid601-Rhone Poulenc) was dissolved in N-methylpyrrolidone was preliminarily treated with N-β-aminoethyl-γ-aminopropyltrimethoxysilane. A layer of plain woven glass cloth made of treated E-glass was impregnated so that the weight in the molded product would be 50%, and dried at 150 ° C for 15 minutes. Hold at 190 ° C. and 50 kg / cm ² for 2 hours and press-mold to obtain a member having a thickness of 312 μm. 20 from the tip by etching
A control electrode member is obtained by retreating 0 μm and leaving an electrode member having a width of 500 μm. The dielectric constant of the part without electrolytic copper foil is 2 at 1MHz.
It was 4.6 at 5 ° C.

FIG. 20A shows the image forming body 1 and the developer carrying body 41.
20 is a sectional view showing the geometrical arrangement of the control electrode member 45 and FIG.
FIG. 3B is a partially enlarged cross-sectional view near the development area A.

20A and 20B, r ₂ represents the radius of the image forming body 1, and χ represents the angle formed with the horizontal direction of the control electrode member 45. The meanings of r ₁ , l ₁ , d, θ ₁ , θ ₂ , θ ₃ are the same as in FIG. U-BIX9028 type color copying machine (manufactured by Konica Co., Ltd.) was changed to a developer carrying amount controlling member 46 to a doctor blade having a gap of 200 μm with the developer carrying roller 41, and this control electrode member 45 was used as an image of the electrode member 46b. Mount toward the forming body side 1 and set the respective dimensional values shown in FIG. 20 to r ₁ = 1
0 mm, r ₂ = 90 mm, l ₁ = 15 mm, d = 0.5 mm, θ ₁ = 0 °,
With θ ₂ = 0 °, θ ₃ = 60 °, χ = tan ⁻¹ 0.1, the surface potential of the non-exposed photoconductor is −850 V, and the surface potential of the photoconductor is 50 −50.
V, the control electrode DC potential was set to -800 V, the DC bias applied to the developer transport body (developing roller) 41 was set to -750 V, the AC bias frequency applied was 10 kHz, and the voltage was set to 0.35 kV _0-p .

As the developer 42, U-BIX 9028 was used as it was except that the developer carrier σ ₁₀₀₀ was changed from the usual 18 emu / g to 25 emu / g.

When the exposed portion of the photoconductor was developed in black, 1.28
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Further, when the exposed portion of the photoconductor was developed by yellow and transferred, and the unexposed portion was developed by black on the transfer paper after fixing and transferred overlaid, the adhesion amount of the black toner was 25 particles / mm ^2, which was extremely small.

There was no deterioration in image quality even after the continuous 50,000 copies in the monochrome mode.

Example 6 Polyamino bismaleimide (Kerimid 601-Rhone Poulenc) was dissolved in N-methylpyrrolidone to prepare a varnish having a concentration of 50% by weight with N-β-aminoethyl-γ-aminopropyltrimethoxysilane. A layer of plain woven glass cloth made of treated E-glass was impregnated so that the weight in the molded product would be 50%, and dried at 150 ° C for 15 minutes. Hold at 190 ° C. and 50 kg / cm ² for 2 hours and press-mold to obtain a member having a thickness of 312 μm. 20 from the tip by etching
The control electrode member 45 is obtained by retreating by 0 μm and leaving the electrode member 45b having a width of 500 μm. The dielectric constant of the part without the electrolytic copper foil was 4.6 at 25 ° C. at 1 MHz.

FIG. 21A shows the image forming body 1 and the developer carrying body 41.
21 is a sectional view showing the geometrical arrangement of the control electrode member 45 and FIG.
FIG. 3B is a partially enlarged cross-sectional view near the development area A.

In FIGS. 21A and 21B, d ₁ is the horizontal distance from the closest point R between the image forming body 1 and the developer transport body 41 to the tip of the control electrode member 45, and d ₂ is the control electrode. This is the closest distance between the member 45 and the developer transport body 41. φ is the image forming body 1
The closest point R between the developer transport body 41 and the developer transport body 41 is an angle formed by the rotation shaft O of the developing roller and the closest approach point U between the control electrode member 45 and the developer transport body 41. Note that r ₁ , l ₁ , r ₁ , θ ₁ ,
The meanings of θ ₂ and θ ₃ are the same as in FIG. U-BI
The developer carrying amount regulating member 46 of the X9028 type color copying machine (manufactured by Konica Corporation) was changed to a doctor blade having a gap of 100 μm with the developer carrying roller 41, and the control electrode member 45 was replaced with the electrode member 45b on the image forming body side. 22 and attach the respective dimension values shown in FIG. 22 to r = 10 mm, l ₁ = 10 mm, d ₁ = 0.5 mm, d ₂ = 0.15
mm, θ ₁ = 0 °, θ ₂ = 0 °, θ ₃ = 60 °, φ = tan ⁻¹ 0.12
The surface potential of the non-exposed portion photoconductor is -850V, the surface potential of the exposed portion photoconductor is -50V, the control electrode DC potential is -800V, and the DC bias applied to the developer transport body (developing roller) 41 is-.
750V, applied AC bias frequency is 10kHz, and its voltage is 0.
Set to 35kV _0-p .

As the developer 42, U-BIX 9028 was used as it was except that the developer carrier σ ₁₀₀₀ was changed from the usual 18 emu / g to 25 emu / g.

When the exposed portion of the photosensitive member was black-developed, it was 1.33.
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Also,
When the exposed portion of the photosensitive member was developed with yellow and then the unexposed portion was developed with black, the amount of black toner deposited was 19 particles / mm ^2, which was extremely small.

There was no deterioration in image quality even after 50,000 continuous copies.

Example 7 A varnish having a concentration of 50% by weight in which polyaminobismaleimide (Kerimid601-Rhone Poulenc) was dissolved in N-methylpyrrolidone was preliminarily treated with N-β-aminoethyl-γ-aminopropyltrimethoxysilane. One layer of treated plain weave glass cloth made of E-glass was impregnated so that the weight of the molded product would be 50%, and dried at 150 ° C for 15 minutes.
Hold at 50 ℃ / cm ² for 2 hours, press-mold, thickness 56
Obtain a member of μm. 200μm from the tip by etching
Control electrode member that retracts and leaves the electrode member 45b with a width of 500 μm
Get 45. The dielectric constant of the part without the electrolytic copper foil was 4.6 at 25 ° C. at 1 MHz. The U-BIX9028 type color copying machine (manufactured by Konica Corp.) was changed to a doctor blade having a gap of 200 μm with the developer conveying roller 41 instead of the developer conveying amount controlling member 46, and the control electrode member 45 was mounted. The respective dimension values shown in r = 10 mm, l ₁ = 6 mm, l ₂ = 4 mm, d = 0.5 mm, θ ₁ = 0
°, θ ₂ = 0 °, θ ₃ = 60 °, the non-exposed area photoconductor surface potential is -850 V, the exposed area photoconductor surface potential is -50 V, the control electrode DC potential is -800 V, and the developer carrier (development) Laura) 41
The applied DC bias was set to -750 V, the applied AC bias frequency was set to 10 kHz, and the voltage was set to 0.058 kV _0-p ).

As the developer 42, U-BIX 9028 was used as it was, except that the developer carrier σ ₁₀₀₀ was changed from 18 emu / g to 25 emu / g.

When the exposed portion of the photosensitive member was developed in black, 1.30
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Also,
When the exposed portion of the photoconductor was developed with yellow and then the non-exposed portion was developed with black, the amount of black toner deposited was extremely small at 1 piece / mm ² .

There was no deterioration in image quality even after the continuous 50,000 copies.

[Embodiment 8] 99.999% pure metallic copper is vapor-deposited on a 99.5% alumina plate having a thickness of 300 μm and 500 μm is deposited on the tip thereof.
A control electrode member 45 having a width electrode member 45b is obtained. The dielectric constant of the alumina plate at 1 MHz was 9.7 at 25 ° C. U-
BIX9028 type color copier (Konica Corporation) developer transfer amount control member 46 and developer transfer roller 41 gap 200μm
This control electrode member 45 is mounted in place of the doctor blade of _{No. 1} , and each dimensional value shown in FIG. 19 is r = 10 mm, l ₁ = 12 mm,
l ₂ = 4.3 mm, d = 0.5 mm, θ ₁ = 0 °, θ ₂ = 0 °, θ ₃ =
At 60 °, the surface potential of the non-exposed photoconductor is -850V, the surface potential of the photoconductor is -50V, and the control electrode DC potential is -800V.
V, the applied DC bias to the developer carrier (developing roller) 41 was set to -750 V, the applied AC bias frequency was set to 10 kHz, and the voltage was set to 170 kV _0-p .

As the developer 42, U-BIX 9028 was used as it was, except that σ _{1000 of the} developer carrier was changed from the usual 18 emu / g to 25 emu / g.

When the exposed portion of the photosensitive member was developed in black, 1.29
Toner of mg / cm ² was adhered to the development, and sufficient image density was obtained with each color of yellow, cyan, and magenta. Also,
When the exposed portion of the photoreceptor was yellow-developed and then the non-exposed portion was black-developed, the amount of black toner adhered was extremely small at 2 particles / mm ² .

There was no deterioration in image quality even after the continuous 50,000 copies.

In the embodiments of the present invention, a modified U-BIX 9028 machine was used as an image forming apparatus. However, the present invention is applicable to a copying machine, a printer, a facsimile machine or a combination machine thereof that forms an image by various developing methods. As described above, the present invention can be similarly used for other electrophotographic apparatuses that form an image by writing an image on the photosensitive drum or the photosensitive belt that is an image forming body.

The control electrode member and the developing method of the present invention are suitable for a two-component developer composed of toner and magnetic particles, but are similarly applied to a magnetic or non-magnetic one-component developer.

[0168]

According to the control electrode member of the present invention and the developing method using the same, the plate-shaped control electrode member can be accurately and stably installed in the developing space of the developing device, and the control electrode can be installed. The development promoting effect of the member is not impaired. This results in uniform high image density and low background density or low color mixture over a long period of time.

[Brief description of drawings]

FIG. 1 is a U-BIX 9028 (Konica) used in an example of the present invention.
Reconstruction machine configuration diagram manufactured by Co., Ltd.

FIG. 2 is a schematic cross-sectional view showing an embodiment of a developing device used in the image forming apparatus of the present invention.

FIG. 3 is a cross-sectional view showing an arrangement example of control electrode members in a developing device.

FIG. 4 is a cross-sectional view showing another arrangement example of control electrode members.

FIG. 5 is a cross-sectional view showing yet another arrangement example of control electrode members.

FIG. 6 is a cross-sectional view showing another example of arrangement of control electrode members.

FIG. 7 is a cross-sectional view showing various examples of the control electrode member.

FIG. 8 is a diagram showing an electrical configuration in the present invention.

FIG. 9 is a cross-sectional view showing a configuration example of a developing device using the control electrode member of the present invention.

FIG. 10 is a cross-sectional view showing another configuration example of the developing device using the control electrode member of the present invention.

FIG. 11 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 12 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 13 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 14 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 15 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 16 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 17 is a cross-sectional view showing still another configuration example of the developing device using the control electrode member of the present invention.

FIG. 18 is a cross-sectional view and a partially enlarged cross-sectional view showing the arrangement of an image forming body, a developer transport body, and a control electrode member.

FIG. 19 is a sectional view of a control electrode member.

20A and 20B are a sectional view and a partially enlarged sectional view showing the arrangement of an image forming body, a developer carrying body, and a control electrode member.

21A and 21B are a sectional view and a partially enlarged sectional view showing the arrangement of an image forming body, a developer carrying body, and a control electrode member.

[Explanation of symbols]

 1 photoconductor drum (image forming body) 2 scorotron charger 3 image writing device 4, 4A, 4B, 4C, 4D developing device 5 transfer device 6 cleaning device 7 platen 8 image reading device 9 paper feeding device 12 fixing device 41 developing device Agent carrier (developing roller) 42 Developer 43 Stirrer 44 Supply roller 45 Plate-shaped member having electrode member (control electrode member) 45a Insulating member 45b Electrode member 45c Holding member 46 Developer transport amount regulating member 47 Scraper A Development Area E1 DC bias power source (developer carrier side) E2 AC bias power source (developer carrier side) E3 DC bias power source (control electrode member side)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Shigeta Konica stock company, 2970 Ishikawa-cho, Hachioji, Tokyo (72) Inventor Toru Komatsu 2970 Ishikawa-machi, Hachioji, Tokyo Konica stock, company

Claims (10)

[Claims] 1. An insulating member which is installed between a developer transport body and an image forming body at an upstream side of a developing space in which development mainly occurs, that is, a developing region or a developer transport direction of the developer transport body. And an electrode member provided on the insulating member, and the dielectric constant of the insulating member at 1 MHz is 25.
A control electrode member for an electrophotographic developing device, which has a temperature of more than 3.5 at ℃. 2. The control electrode member for an electrophotographic developing apparatus according to claim 1, wherein the electrode member is installed on a surface other than the surface of the insulating member on the developer carrier side or inside thereof. 3. The electrode member is installed only on the downstream side of the developer carrying direction of the developer carrying body with respect to the closest position of the insulating member to the developer carrying body. A control electrode member for an electrophotographic developing apparatus as described. 4. The insulating member is made of a resin reinforced with an inorganic fiber or an organic fiber.
A control electrode member for an electrophotographic developing apparatus according to item 1. 5. The control electrode member for an electrophotographic developing apparatus according to claim 1, wherein the thickness of the electrode member is 20 to 500 μm, and the length measured in the developer conveying direction is 5 to 50 mm. 6. A control electrode member comprising an insulating member having a dielectric constant at 1 MHz of more than 3.5 at 25 ° C. and an electrode member provided on the insulating member in the developer carrying direction of the developer carrying body. A developing method characterized in that one end is fixedly held on the upstream side of the developing area, and the other end is inserted between the developer conveying body and the image forming body toward the downstream side so as to be positioned in the developing area. 7. The developing method according to claim 6, wherein the control electrode member is installed in pressure contact with the developer on the developer transport body. 8. The developing method according to claim 6, wherein the control electrode member is installed in pressure contact with the image forming body. 9. The developing method according to claim 6, wherein the developer carrying direction of the developer carrying body and the moving direction of the image forming body are the same. 10. The developing method according to claim 6, wherein the developer on the developer transport body is kept in a non-contact state with the image forming body.