JPH05165338A - Electrophotographic development device - Google Patents

Abstract

PURPOSE:To spread and extend a conveyance layer for a developer uniformly on a conveying and carrying surface, to eliminate time-series variation in layer thickness, and to increase developer durability for small-particle-diameter and/or low-softening-point toner. CONSTITUTION:The development device has a developer carrier 3 which is equipped with a fixed magnet body inside and carries a thin-layer two- component developer in a development area and a rod-shaped developer amount control body 5 which presses the developer against the developer carrying surface of the developer carrier 3 to control the amount of the conveyed developer. A lubricant is incorporated in the two-component developer, the pressing surface of the rod-shaped developer amount control body is a curved surface of 0.5-15mm in radius of curvature which is made of a rigid material, and the developer carrier surface is a roughened surface after a sand blast treatment using indefinite-shape particles and then spherical large particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device applicable to the development of a latent image formed on an image forming body, especially a photoconductor used in an electrophotographic copying machine.

[0002]

BACKGROUND OF THE INVENTION In an electrophotographic copying machine using a one-component or two-component developer, in order to obtain a good image, the layer thickness of the developer on a developer carrier (also referred to as a developing sleeve or simply sleeve) is set. It must be thin and uniform.

Conventionally, as a developer amount regulating body, the layer thickness has been regulated by a fixing regulating plate which has been used for a long time, but there is a limit in the accuracy of mechanical attachment between the developer carrying body and the fixing regulating plate. The minimum layer thickness is about 0.3 mm. Moreover, it was difficult to obtain a uniform and even thin layer by this method. Various developer layer thickness regulating members other than the fixed regulating plate have been devised in order to obtain a more uniform thin layer.

For example, in a developing device using a one-component developer, an elastic plate having one end fixed as a developer layer thickness regulating member (hereinafter referred to as a regulating member) pressed against the sleeve surface (Japanese Patent Laid-Open No. 54-43038). ), An elastic plate obtained by laminating a metal plate and a soft elastic plate (JP-A-54-51848), and an elastic roller for intermittently or continuously pressing (JP-A-59-126567 and 59-129879). ,
No. 60-12627) is proposed.

Further, in a developing device using a two-component type developer, a method of pressing the front end image of the elastic plate onto the sleeve in a direction in which the developing agent is approached (Japanese Patent Laid-Open No. 62-191868,
No. 62-191869), a method in which a magnet body is installed on the back of a solid plate and pressed by the magnetic force between the magnet body and the magnet body built into the sleeve (Japanese Patent Laid-Open Nos. 61-189582 and 62-75563), and further regulations A method (Japanese Patent Laid-Open No. 2-50184) in which the member itself is a rigid magnetic rod has been proposed.

However, in the case where a thin layer is formed by pressing the elastic regulating plate against the sleeve having rigidity, the elastic plate is liable to change its elastic modulus or to be permanently deformed during long-term use, and has durability as a regulating member. Is short, and when the position of the elastic plate changes slightly when it is attached, the amount of tip play and pressing force change, making it difficult to regulate the layer thickness in a stable manner.
Therefore, it has a serious drawback that the mounting accuracy is extremely strict during mass production.

Further, in the magnetic force pressing method, although the effect of unraveling the toner agglomeration by the back surface of the regulating member and the magnets built in the sleeve is recognized, it is possible to use the magnetic force through the solid plate-shaped regulating member. The pressure fluctuation due to the distance fluctuation easily occurs, the pressure effect on the developer layer is not stable, and the toner or the developer agglomerates pass through, or conversely, a constant layer thickness cannot be obtained, which causes clogging. However, there is a drawback that the image quality is adversely affected by causing white stripes.

Further, in order to eliminate the uniform thickness of the developer on the sleeve surface and the time-series layer thickness undulation, the adhesive force with the toner on the sleeve surface and the rough surface shape of the sleeve surface which influences the transport amount,
Also, it is necessary to examine the fluidity of the entire developer and the lubricity of the toner particles themselves.

On the other hand, in recent years, the demand for color copying has increased, and the color softening point of toner has been reduced to meet the demand for colorization of copying machines and reduction of power consumption.

A two-component developer having good color reproducibility is suitable for colorization on the premise of multiple development, and a uniform thin layer development layer is required in the batch transfer system of laminated color toner image layers.

Further, when the softening point of the toner is lowered, the toner itself may melt due to the friction between the sleeve or the regulating member and the toner, and the toner may stick to the sleeve or the regulating member. In general, the surface of the sandblasted developing sleeve has irregularities having irregular sharp projections as shown in an enlarged view of the surface state of FIG. 3B, which contributes to the conveyance of the developer, but is too sharp, It was easy for melting to occur due to frictional heat at the convex portion. If the toner sticks or the like, the carry amount changes, and this becomes a major cause of uneven density and reduced density.

[0012]

Objects of the present invention are: (1) To provide a developing device in which the thickness of the developer transport layer is evenly spread on the transport-carrying surface and the layer thickness does not fluctuate over time. Another object is (2) to provide a developing device having a high developer durability against a toner having a small particle size and / or a low softening point.

[0013]

The above object of the present invention is to provide a developer carrying body containing a fixed magnet body and carrying a thin layer two-component developer into a developing area, and a developer carrying surface of the developer carrying body. In a developing device having a rod-shaped developer amount regulating member that presses the developer by pressing to regulate the amount of the conveyed developer, the two-component developer contains a lubricant, and the pressing surface of the rod-shaped developer amount regulating member is made of a rigid material. It is achieved by an electrophotographic developing apparatus characterized by a curved surface having a radius of curvature of 0.5 to 15 mm and a developer carrying surface being a rough surface sand-blasted with irregular-shaped particles and then large-sized particles.

In the present invention, a rigid material means a rigidity factor of 1.
0 ⁴ kg / cm ² or more, specifically (0.8
~ 1.6) × 10 ⁶ kg / cm ^{2 About} iron, iron, its alloys and other magnetic metals, and magnetic powders (1.0-10) × 10 ⁴ kg / cm ² A hard resin having a rigidity of is also used as the developer amount regulator of the present invention. Further, iron and iron alloys plated with chromium or the like are also used.

The present inventors conducted the following experiments.

Using the experimental apparatus as shown in FIG. 1, layers were formed by magnetic and non-magnetic cylindrical rods 50. That is, the magnet roller 4 having a plurality of magnetic poles was fixed, and the outer side of the magnet roller 4 was rotated in the direction of the arrow. This sleeve 3
The columnar rod 50 was pressed using a spring balance. The pressing position of the cylindrical rod 50 was set at a position facing the magnetic pole of the magnet roller 4. When the parameters were the pressing force of the cylindrical rod 50 and the diameter of the cylindrical rod, a graph as shown in FIG. Here, the pressing force is the sum of the load F of the spring balance and the self-weight of the cylinder rod in the case of a non-magnetic cylinder rod, and is the sum of the attraction force by the magnetic force in the case of a magnetic cylinder rod.
In the figure, the curve shown by the solid line shows the case of a magnetic cylindrical rod, and the curve shown by the chain line shows the case of a non-magnetic cylindrical rod. As is clear from the figure, the amount of developer conveyed is determined by the cylindrical rod 50 and the sleeve 3.
It is shown that the developer that enters the wedge-shaped portion formed by and is determined by the balance between the force exerted on the cylindrical rod and the force of the spring or the spring and the magnetic force or the like in the sleeve direction of the cylindrical rod. Further, in the case of the magnetic cylindrical rod, it is shown that the transport amount of the developer is more stable with respect to the fluctuation of the pressing force than the non-magnetic cylindrical rod. Non-magnetic SUS such as SUS310, Al, or polycarbonate is used as the material of the cylindrical rod 50, and magnetic SU such as SUS416 or SUS430 is used as the magnetic cylindrical rod 50.
The results are shown using a hard resin containing S, an iron alloy, and magnetic powder.

In this apparatus, a cylindrical rod is used with a radius of curvature of 0.5 mm.
A cylindrical rod having a rigidity and magnetism of up to 15 mm, preferably 1 mm to 10 mm, and being set so that a pressing force of (1-15) gf / mm is applied, it is considerably A stable and close to the desired carrying amount was obtained. However, if the pressing force is too small, the regulation force of the developer amount is reduced and stable regulation cannot be performed. Further, it is not preferable because it is easily affected by external influence such as vibration of the developing device. Agglomerates of the developer are also passed through, and a uniform developer layer cannot be formed.

Further, if the pressing force is too high, the load on the developer becomes large, and the developer component is remarkably adhered in the vicinity of the pressing portion of the regulating member, and the pressing portion is clogged to form a thin layer. Can not be.

By the way, the surface of the sleeve is generally subjected to precision sandblasting, but the surface condition is such that the convex and concave portions of the irregularities are sharp, and this causes a phenomenon in which the toner particles melt when the pressure is regulated. ..

In order to solve this, in the present invention, the sandblasting treatment is carried out in two steps, and in the first treatment, amorphous particles such as alumina and metal particles (for example, size 400) are used.
~ No. 600) with 10 points average roughness Rz on the sleeve surface 0.1 ~
2μm rough surface, and then secondary treatment with zirconia, glass beads, ceramics, etc.
0-400) depending on Rz; 0.1-10 μm, preferably 5-1
A rough surface of 0 μm was finished.

FIG. 3 shows a sectional curve of the surface of the sleeve surface (non-magnetic SUS) obtained by the sandblast treatment. Figure 3
(B) is a cross-sectional curve after the primary treatment, which is composed of irregularities having sharp corners. However, after the secondary treatment, as shown in FIG. 9A, the sharp corner disappears and the depression becomes shallow, and there is almost no room for gripping and gripping the toner particles.

The measured surface glossiness thus obtained was in the range of 2-1400% Gs (20 °).

As a result of the above-mentioned various studies, the pressing force of the rough surface on the sleeve surface is appropriate to be (1-15) gf / mm, and (2-10) gf / mm is particularly preferable. Further, in the case of a two-component developer using a magnetic spherical carrier, the above range is optimum as the pressing force. As a result, a stable image with a stable density was obtained.

As the means for pressing the cylindrical rod toward the sleeve, it is preferable to use a non-linear elastic member having a characteristic that the load (repulsive force) does not fluctuate with respect to the bending amount in the usage range including before and after the usage state. is there. An example of the characteristic curve of the non-linear elastic member having such characteristics is shown in FIG. Shown are four types of PORO with slightly different performance.
A characteristic curve for N (trade name of INOAC) shows that the horizontal axis represents the amount of flexure and the vertical axis represents the load, and the vertical axis represents the load, which is a stable region with a gentle slope.

By using a non-linear elastic member that presses within this range of use as the pressing member for the cylindrical rod, even if there is an error in the accuracy of the parts of the casing or holder, or due to variations in the mounting condition of the developing device, that variation is absorbed. As the pressing force of the cylindrical rod against the sleeve is small, the layer thickness of the developer is kept uniform.

That is, it was confirmed that a very stable transport amount and a uniform thin layer can be formed as compared with a conventional developing device having a developer amount regulating member and a conventional developing sleeve having a surface state.

A coating may be provided on a rod-shaped developer amount regulating member such as a cylindrical rod within the range where the effects of the present invention are not lost, and a coating of polyurethane rubber or silicone rubber may be provided.

The lubricant used in the two-component type developer according to the present invention is preferably a metal salt of a fatty acid such as stearic acid or palmitic acid, for example zinc, aluminum, lead,
Examples thereof include salts of magnesium and lithium, and aluminum stearate and magnesium thereof are particularly preferable. The amount of the lubricant added is 0.01 to 2 parts by weight with respect to 100 parts by weight of the toner.

The action of the lubricant is such that it adheres to and sits on the toner particles of the fluidizing agent particles to reduce the contact area, or the toner particles are caught in the unevenness of the sleeve surface which does not exert the roller action between the contact objects. It is possible to prevent the above, and to remarkably enhance the spreadability of the developer on the sleeve surface in synergy with the blunting effect of the projection of the cross-sectional curve of the sleeve surface, and to improve the durability of the developer, the sleeve, and the regulating member.

In the present invention, the carrier for constituting the two-component developer is not particularly limited, but a resin-coated carrier obtained by coating the surface of magnetic particles with a resin can be used.

The magnetic particles constituting the carrier include
A substance that is strongly magnetized in that direction by a magnetic field, such as iron,
Particles made of a ferromagnet such as ferrite or magnetite, a metal or an alloy exhibiting ferromagnetism such as nickel, cobalt, or a compound containing these elements can be used.

As the resin for coating the resin-coated carrier,
For example, a styrene-acrylic copolymer such as polystyrene-methyl methacrylate, a silicone compound, a fluorine resin and the like can be preferably used.

When the average particle diameter of the carrier is 20 to 100 μm, preferably 20 to 70 μm, the carrier adhesion phenomenon is further reduced,
The image can be made clear and it can be prevented. here,
What is the average particle size (weight) of the carrier?
The value measured using (manufactured by Nikkiso Co., Ltd.).

The toner particles according to the present invention have a particle size of 1 to 20 μm.
m, preferably 3 to 9 μm, a toner softening point of 90 to 150 ° C., and a glass transition point of 20 to 70 ° C.

The binder resin used in the toner is not particularly limited, but a polyester resin which is a copolymer can be preferably used in terms of the negative charging performance of the toner.

Examples of other binder resins include epoxy resins, vinyl polymers and styrene copolymers.

The toner according to the present invention contains a colorant in the binder made of the above-mentioned polymer resin, and may further contain a property improving agent in the resin, if necessary. Good.

Examples of the colorant include carbon black, chrome yellow (CINo.14090), DuPont oil red (CINo.26105), quinoline yellow (CINo.
No.47005), Malachite Green Oxalate (CIN
o.42000), mixtures thereof, and the like can be used. The amount of colorant used is usually 100 parts by weight of toner.
It is 0.1 to 20 parts by weight, and particularly preferably 0.5 to 10 parts by weight.

As the property improving agent, a fixing property improving agent,
There are charge control agents and others.

Examples of the fixability improver include polyolefin, fatty acid metal salt, fatty acid ester and fatty acid ester wax, partially saponified fatty acid ester, higher fatty acid, higher alcohol, liquid or solid paraffin wax, polyamide wax, polyhydric alcohol. Ester, silicone varnish, aliphatic fluorocarbon, etc. can be used. Especially the softening point (ring and ball method JIS K2531) is 6
Waxes at 0-150 ° C are preferred.

As the charge control agent, those conventionally known can be used, and examples thereof include nigrosine dyes, metal-containing azo dyes, metal complex salts and the like.

Further, the toner of the present invention is preferably used by mixing inorganic fine particles such as a fluidity improver.

The inorganic fine particles used in the present invention are particles having a primary particle size of 5 mμ to 2 μm, preferably 5 to 500 mμ. The specific surface area by the BET method is preferably 20 to 500 m ² / g. The mixing ratio with 100 parts by weight of toner is 0.01 to 5 parts by weight, preferably 0.01 to 2.0 parts by weight. Examples of such inorganic fine powder include silica fine powder, alumina, titania, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, cerium oxide, antimony trioxide, zirconium oxide, silicon carbide and the like. However, fine silica powder is particularly preferable.

The amount used is preferably in the range of 0.01 to 5 wt% of the total toner, and more preferably in the range of 0.05 to 2 wt%.

The toner of the present invention is mixed with a carrier to prepare a toner.
Used as a component developer.

In order to produce the two-component developer used in the present invention, first, the colorant is added to the toner binder, various additives are added if necessary, and the mixture is mixed by a ball mill or the like and kneaded. A toner powder is obtained through the steps of pulverization, classification and classification. Then, a lubricant is added to the toner powder,
The developer can be obtained by adding the inorganic fine particles, mixing the mixture with a turbula mixer or the like, and mixing with a separately prepared carrier.

As the developing method used in the present invention, various known developing methods can be adopted. In particular,
(1) A magnetic brush of a developer is carried on a sleeve, for example, in a state where the layer thickness is larger than the gap in the developing area, the magnetic brush is carried into the developing area, and the magnetic brush is rubbed against the latent image by the magnetic brush. A contact type magnetic brush method in which toner particles or a group of particles therein are attached to a latent image for development, (2) a magnetic brush of a developer is carried on a sleeve, for example, in a state in which the layer thickness is smaller than the gap in the developing region, The magnetic brush is carried into the developing area, and an oscillating electric field is applied to the developing area to cause the toner particles or particle groups in the magnetic brush to fly, thereby adhering the toner particles or particle groups to the latent image for development. A non-contact magnetic brush method or the like can be used.

[0048]

Embodiments Based on the above results, an embodiment of a developing device to which the present invention is applied will be described first with reference to FIG.

Example 1 FIG. 5 shows a cross section of the main part of a developing device, in which 1 is an image carrier, 2 is a housing, 3 is φ20 mm non-magnetic stainless steel, and two steps of sandblasting are applied to Rz 5 μm. Rough developing sleeve, 4 magnet roller with 11 poles and over 500 gauss, 5 stainless steel rod (cylindrical rod) having rigidity and magnetism to regulate the amount of developer, and 15 holding the rod 5. A holder 6 is a spring material for allowing the developer to be conveyed by pressing the cylindrical rod 5 and the developing sleeve 3, and the cylindrical rod 5 is pressed against the developing sleeve 3 with a constant load without the developer intervening. To be done. 7 and 8 are first
The second stirring member, 9 is a supply roller, 10 is a scraper, and 11 is a stirring partition plate.

The toner replenished in the apparatus is sufficiently stirred and mixed with the carrier by the first stirring member 7 which rotates in the direction of the arrow and the second stirring member 8 which rotates so as to overlap each other in the opposite direction. The upper developer D is sent to the developing sleeve 3 via the supply roller 9.

The first stirring member 7 and the second stirring member 8
Is a screw-shaped member having left-handed spiral fins that rotate in mutually opposite directions, and the toner and the carrier conveyed to the inner side by the thrust of the second stirring member 8 are in the inner side in the drawing. The upper edge is gradually passed over the agitating partition plate 11 to move toward the first agitating member 7 side, and is conveyed to the front side of the drawing by its thrust, and is uniformly triboelectrically charged by the mixing action of the toner and the carrier in the meantime. The developer D is formed into a layered form on the peripheral surface of the developing sleeve 3 by the sponge-like supply roller 9 which rotates in the direction of the arrow.

The developers used in the example shown in FIG. 5 are as follows.

[Developer] Carrier: 50 μm Core: Ferrite shell: Styrene (St) / methyl methacrylate (MM
A) Copolymer (4/6) Toner: 8 μm binder ... St / MMA / butyl acrylate (BA) = 70 /
15/15 Mw = 26000, Mn = 8000 Glass transition point (Tg) = 50 ° C, Softening point (Tsp) = 110 ° C Colorant ... Carbon black 4wt% Lubricant: Aluminum stearate, 0.2wt% added Fluidizer: Addition of silica particles, 1.0 wt% In this device, the cylindrical rod 5 was applied with a load of (2-6) gf / mm at a position facing the magnetic poles of the magnet roller 4, and spread uniformly and without unevenness ( 6-10) mg
A carrying amount of / cm ² was obtained. As a result, a stable image having uniform density was obtained. At that time, the magnetic flux density at the pressing position on the surface of the developing sleeve 3 was 600 gauss. FIG. 6 compares the amount of developer conveyed when a non-magnetic cylindrical rod having a rigidity of 6φ mm is used in place of the magnetic cylindrical rod 5.

Regarding the amount of conveyance when the cylindrical rod 5 having rigidity and magnetism is used, the relationship between the pressing force and the amount of conveyance when the diameter is changed can be obtained as shown in FIG. A more appropriate transport amount can be selected. In particular, when the radius of curvature was 0.5 to 15 mm, a stable conveyance amount was obtained in which the force exerted by the developer D on the cylindrical rod 5 and the force of the cylindrical rod 5 toward the sleeve 3 were well balanced. More preferably, when the radius of curvature is 1 to 10 mm, the variation in the carry amount is very small regardless of the variation in the pressing force, and a uniform and thin developer layer thickness can be obtained.

Although non-magnetic stainless steel is used as the material of the developing sleeve 3 having rigidity, the same effect can be obtained by using materials having rigidity such as aluminum metal, hard resin, glass and ceramics. It was If the surface roughness Rz of the developing sleeve 3 is within the range of the present invention, the same effect can be obtained.

As described above, the developing sleeve 3
A uniform and stable thin developer layer in the range of 100 to 450 μm, preferably 150 to 400 μm is formed on the surface for a long period of time.

In this embodiment, the fixed magnet roller 4 is used.
This thin developer layer adhered on the peripheral surface of the developing sleeve 3 which rotates in the arrow direction (clockwise direction) on the outer side thereof and the latent image on the image carrier 1 which rotates in the arrow direction in the developing area 12. The image was developed in a non-contact manner at intervals to form a toner image.

Further, when a slipping test of the developing device was carried out using the above-mentioned developer, no toner fusion was observed in the sleeve in the sleeve according to the present invention even after 2 hours.
For sleeves that are not subjected to step sandblasting
Fusing of the toner was observed after 15 minutes.

Example 2 The following developer was used in the developing device used in Example 1.

[Developer] Carrier: 25 μm Core: Ferrite shell: Styrene (St) / methyl methacrylate (MM
A) Copolymer (4/6) Toner: 6 μm binder ... St / MMA / butyl acrylate (BA) = 70 /
15/15 Mw = 26000, Mn = 8000 Glass transition point (Tg) = 50 ° C, Softening point (Tsp) = 110 ° C Colorant ... Carbon black 4wt% Lubricant: Zinc stearate, 0.2wt% added Fluidizer: Addition of silica and titanium oxide to 1.0 wt% As in Example 1, a good uniform thin film spreading layer of the developer could be formed with good stability, and no fusion of the toner to the sleeve occurred.

Further, when the lubricant was removed, uniform spreadability was often hindered.

[0062]

As described above, the developing device of the present invention is rigid and has the same rigidity and magnetic property as the developer carrying member (developer sleeve) whose surface is roughened and whose convex portion is rounded. By forming a developer layer forming portion by pressing a developer amount regulating body formed of a member having rigidity with a small radius of curvature, and by adding a lubricant to the used two-component developer, It is not affected by changes in the rotation speed and pressing position of the developer carrier, and in particular, the stability of the transport amount with respect to pressing force fluctuation can be obtained, and a developer layer having a stable thickness can be obtained. .. Therefore, as compared with the conventional one, a uniform and stable developer layer can be obtained under a low load.

Further, it is less likely to cause clogging due to foreign matters, and the pulverizability of aggregated toner and developer lumps is excellent, and white lines are less likely to appear on an image. Further, the fluctuation of the developer amount after the regulation due to the change of the pressing force at the pressing portion of the developer amount regulating member with respect to the developer carrying member is extremely small, and the developing device having excellent developing property becomes possible. It is possible to provide a high-quality image which prevents the developer component from adhering to the regulating member and can stably form a uniform and thin layer without causing uneven density or lower density.

Since the developing device of the present invention does not deform the developer carrying member (developing sleeve) or the regulating member during long-term use and has little change in the attraction force due to the magnetic force, it is extremely durable as the regulating device. Furthermore, the mounting accuracy is relatively large even during mass production, and it is highly practical.

Moreover, since the developer control area is small, an adverse effect due to unnecessary triboelectric charging with the developer is unlikely to occur and a good image can be obtained.

In addition, even when the regulating member is replaced, the mounting is easy and the maintainability is high.

Further, when the non-linear elastic member is used as the pressing member for the cylindrical rod, the error of the parts accuracy of the casing and the holder part and the variation at the time of assembly are absorbed. A developing device is provided in which a good amount of developer can be conveyed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an experiment which is the basis of the present invention.

FIG. 2 is a diagram showing the relationship between the presence / absence of magnetism, the curvature at the pressing portion, the pressing force, and the carry amount obtained by the experiment of FIG.

FIG. 3A is a surface state diagram of a developing sleeve surface in the present invention. FIG. 2B is a surface state diagram of the conventional developing sleeve surface.

FIG. 4 is a graph showing the relationship between deflection and load for an example of a non-linear elastic body.

FIG. 5 is a developing device used in the present invention.

FIG. 6 is a relationship between a transport amount and a pressing force obtained by the developing device of the present invention.

FIG. 7 is a relationship between a transport amount and a pressing force obtained by the developing device of the present invention.

[Explanation of symbols]

 1 image carrier 3 developing sleeve 4 magnet roller 5 bar (cylindrical bar) 6 spring material 15,35 holder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Kobayashi Konica Co., Ltd. 2970 Ishikawa-cho, Hachioji-shi, Tokyo

Claims (1)

[Claims] 1. A developer carrying member which incorporates a fixed magnet body and carries a thin layer two-component developer into a developing area, and a developer carrying member which presses the developer toward a developer carrying surface of the developer carrying member. A developing device having a rod-shaped developer amount regulating body for regulating the developer amount, wherein the two-component developer contains a lubricant, and the pressing surface of the rod-shaped developer amount regulating body is made of a rigid material.
The electrophotographic developing device is characterized in that the developer carrying surface is a rough surface which is sandblasted with irregular-shaped particles and then spherical large particles.