JPH0619322A - Developing device - Google Patents

Abstract

PURPOSE:To provide the compact developing device which can reproduce development with high image quality by attaining always stable developer regulation as the irregular ruggedness of a developer carrying member is corrected and the sharp projections on the surface to carry the developer are evened at the time of production. CONSTITUTION:This developing device has the developer carrying member 3 having an internally fixed magnet body and rigidity and a bar-shaped developer regulating body for regulating the amt. of the developer. The pressing part of the developer regulating body is a material which is formed to 0.5 to 15mm radius of curvature and has rigidity and magnetism. The surface of the developer carrying member 3 is subjected to a sandblasting treatment by indefinite form particles and is then further subjected to a ruggedness forming treatment to impart the sandblasting treatment by large spherical particles. The conditions of the sandblasting treatment by the large spherical particles are 2 to 6kg/cm<2> air pressure, 100 to 200mm distance W from the ejecting part for the large spherical particles to the surface of the developer carrying member 3 and 10 to 210mum particle sizes of the large spherical 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 applied to the development of a latent image on an image forming body, particularly an image forming body used in an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus 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). Is required to be thin and uniform. Conventionally, the layer thickness is regulated by the fixed regulation plate, but there is a limit in the mechanical mounting accuracy between the developer carrying member and the fixed regulation plate, and the layer thickness is about 0.3 mm as the lower limit. .

Therefore, the applicant of the present invention has previously disclosed the Japanese Patent Laid-Open No. 2-50.
As disclosed in Japanese Patent Publication No. 184, in order to stably form a good image, the layer thickness of the developer on the developer carrying member is made uniform and stably formed, and the aggregated developer or toner is developed. Provided is a developing device capable of preventing the developing device from moving to an area.

This developing device has a fixed magnet body, a developer carrying body which has the above-mentioned magnet body inside, and has a rigidity for carrying a developer on its surface, and a developer carrying body facing the magnet body. It has a rod-shaped developer amount regulating body that is pressed against the body and regulates the amount of the developer carried on the developer carrying body, and the pressing portion of the developer amount regulating body with the developer carrying body is rigid and It is a magnetic material and has a radius of curvature of 0.5 to 15 mm.

This developing device forms a developer layer by pressing a developer amount regulating member formed of a magnetic member having rigidity and magnetism and having rigidity of a small radius of curvature on a developer carrier having rigidity. By configuring the parts, it is possible to obtain a developer layer having a stable thickness, which is not affected by changes in the rotation speed and the pressing position of the developer carrier, and which is particularly stable in the transport amount against fluctuations in pressing force. As a result, a uniform and stable developer layer can be obtained under a low load.

Further, it is difficult to cause clogging due to foreign matters and the pulverizability of agglomerated toner and developer lumps is excellent, and it is difficult for white lines to appear on the image. Further, the fluctuation of the developer amount after the regulation due to the change of the pressing force of the pressing portion of the developer amount regulating member against the developer carrying member is extremely small, and the developing device having excellent developing property becomes possible. It is possible to prevent the developer component from adhering to the regulating member, and thus to form a stable and uniform thin layer, and to provide an image of excellent quality that does not cause uneven density or decrease in density.

Further, since the developing device is not deformed when the regulating member is used for a long period of time and the attracting force due to the magnetic force is little changed, the durability as the regulating strength is extremely large. Furthermore, the mounting accuracy is relatively large even during mass production, and it is highly practical. In addition, even when the restriction member is replaced, the attachment is easy and the maintainability is high.

Further, the developing device serves as a pressing member for a cylindrical rod,
When a non-linear elastic member is used, an error in accuracy of parts of the casing and the holder part and a variation at the time of assembly are absorbed, so that a good amount of developer can always be stably conveyed even if an adjustment part is not provided.

[0009]

By the way, in such a developing device, since the surface of the developer carrier has irregular irregularities, the developer amount regulation is stable depending on the location on the developer carrier. If not, variations will occur, causing uneven density and unevenness.

Further, since the surface of the developer carrying member has irregular irregularities, toner resin or the like may be fused to the developer carrying member, which may cause uneven density.

According to the present invention, these problems are solved, irregular irregularities of the developer carrying member during manufacturing are improved, and sharp projections on the surface of the developer carrying member carrying the developer are crushed.
We provide a compact developing device that can reproduce high-quality images by always achieving stable developer regulation, and a developing device that can enhance the durability of the developer even with small particle size toner and low softening toner. The purpose is to do.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a developer carrier having a magnet body fixed inside and a rigidity, and a developer carrier provided to face the magnet body. In a developing device having a rod-shaped developer regulating body that regulates the amount of developer on the developer carrying body, the pressing portion of the developer regulating body that presses the developer carrying body has a radius of curvature of 0.5 to 15 mm. With a material having rigidity and magnetism, the developer carrier is subjected to a sandblasting treatment with irregular shaped particles on the surface carrying the developer, and then subjected to a concavo-convex forming treatment for imparting a sandblasting treatment with spherical large particles, The conditions for sandblasting with the spherical large particles are dry sandblasting, and the air pressure is 2 to 6 kg / c.
m ^2, 100 to 200 m distance from the injection portion of the spherical large particles to the surface for carrying the developer of the developer carrying member
m, and the particle size of the spherical large particles is 10 to 210 μm.

The developer used in the present invention is preferably a two-component developer, and the two-component developer has a function of self-cleaning the developer components adhering to the regulator by a carrier, and is more effective than the one-component developer. A developer layer that is stable for a long period of time can be formed.
Examples of this two-component developer include a non-magnetic toner having a particle size of 1 to 20 μm (preferably 3 to 9 μm) and a particle size of a ferrite core coated with a resin material of 20 to 100 μm (preferably 30 to 60 μm). A developer composed of the carrier of 1. is preferably used in the developing device to which the present invention is applied. This toner has a toner softening point of 90 to 150 ° C.,
The toner glass transition point is preferably 20 to 70 ° C.

According to the present invention, a stable thin layer can be formed by pressing a rigid rod-shaped magnetic member as a developer amount regulating member on the rigid developer carrier.

In the present invention, having rigidity means having a large rigidity, that is, a rigidity of 10 ⁴ K.
g / cm ² or more, specifically (0.8-1.
6) Rigidity of about (1.0 to 10) × 10 ⁴ Kg / cm ² containing various magnetic metals such as iron and its alloys and magnetic powder having a rigidity of about 10 × ⁶ Kg / cm ^2. A hard resin having a rate is also used as the developer amount regulator of the present invention. Further, iron and iron alloy plated with chromium or the like are also used. Further, having magnetism means having a property of being attracted to a magnet.

The inventors conducted the following experiment.

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 developing sleeve 3 was rotated on the outer side in the arrow direction. The cylindrical rod 50 was pressed against the developing sleeve 3 by using a spring stopper 100. The pressing position of the cylindrical rod 50 was set to a position facing the magnetic pole of the magnet roller 4. When the parameters were the pressing force of the columnar bar 50 and the diameter of the columnar bar 2R, a graph as shown in FIG. 2 was obtained for the transport amount.

Here, the pressing force is the sum of the weight F of the spring bar 100 and the self-weight of the cylinder rod 50 in the case of a non-magnetic cylinder rod, and the sum of the attraction force by the magnetic force in the case of a magnetic cylinder rod. Is. In FIG. 2, the curve shown by the solid line shows the case of a magnetic cylindrical rod, and the curve shown by the chain double-dashed line shows the case of a non-magnetic cylindrical rod. As is apparent from FIG. 2, the amount of the developer conveyed is determined by the force exerted by the developer, which slips into the wedge-shaped portion formed by the cylindrical rod 50 and the developing sleeve 3, on the cylindrical rod, and the spring or the spring and the magnetic force. It is shown that it is determined by the balance with the force of the formed cylindrical rod in the direction of the developer carrying member.

Further, in the case of the magnetic cylindrical rod, it is shown that the amount of the developer conveyed is stable with respect to the fluctuation of the pressing force as compared with the non-magnetic cylindrical rod. As the material of the cylindrical rod 50, SUS310
The results obtained by using non-magnetic SUS such as Al and polycarbonate, and using magnetic resin such as SUS416 and SUS430, magnetic SUS such as SUS430 and iron alloy, and hard resin containing magnetic powder as the magnetic columnar rod 50 are shown.

In this apparatus, the cylindrical rod 50 is a rigid and magnetic cylindrical rod having a radius of curvature of 0.5 mm to 15 mm, preferably 1 mm to 10 mm, and (1 to 15) gf / mm.
When a setting was made so that a pressing force of was applied, a stable and desired transport amount was obtained regardless of the operation of this experimental device. If the pressing force is too small, the regulation force of the developer amount decreases, 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.

If the pressing force is too high, the load on the developer becomes large, and the developer components are noticeably adhered in the vicinity of the regulation portion of the regulation body, so that the developer cannot withstand long-term use. Also, even small lumps of paper powder, rubber, and developer are clogged in the regulation portion, and white lines are likely to occur.

The pressing force is selected from the above-mentioned various viewpoints (1
.About.5) gf / mm is appropriate, and (2-10) gf / mm is particularly preferable. Further, in the case of the two-component developer using the magnetic spherical carrier, the above-mentioned range is optimum as the pressing force, and as a result, a stable image having a uniform density can be obtained.

As a means for pressing the cylindrical rod toward the developer carrying member, 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 U including before and after the usage state is used. It is preferable to use.
FIG. 3 illustrates an example of a characteristic curve of a non-linear elastic member having such characteristics. Shown are characteristic curves for four types of PORON (trade name of INOAC, Inc.) with slightly different performances. When the amount of deflection is taken on the horizontal axis and the load is taken on the vertical axis, a gentle slope is stabilized in the operating range U. It indicates that the area.

By using a non-linear elastic member that presses in this range of use as a pressing member for the cylindrical rod, the fluctuation can be absorbed even if the accuracy of the parts of the casing or the holder is incorrect or the developing device is assembled. There is little fluctuation in the pressing force of the cylindrical rod on the developer carrying member, and the layer thickness of the developer is kept uniform. That is, it was confirmed that this developing device can form a very stable transport amount and a uniform thin layer. In addition, a coating may be provided on a rod-shaped developer amount regulating member such as a cylindrical rod or the like, and a coating of polyurethane rubber or silicon rubber may be provided as long as the effect of the present invention is not lost.

In the present invention, the surface of the developer carrying member carrying the developer is subjected to the unevenness forming treatment, and the method of this unevenness forming treatment is the sandblasting treatment. After the sandblasting treatment with the irregular particles, the spherical large particles are further added. A two-step process for applying the sand blast process is performed. FIG. 4 shows the principle of the sandblasting process. Compressed air and solid particles are supplied to the sandblasting device 40, and the sandblasting device 40 operates to the surface of the developing sleeve 3 carrying the developer. Solid particles are accelerated and jetted by the force of compressed air.

As described above, according to the present invention, the surface of the developer carrying member carrying the developer is subjected to the unevenness forming treatment by the two-step blasting treatment, and the surface roughness Rz after the sandblasting treatment by the one-step irregular-shaped particles is 0.1 to 2 μm is preferable, and further, in the sand blasting treatment with two large spherical particles, the surface roughness Rz is preferably 0.1 to 10 μm,
By carrying out such a sand blasting process, an appropriate amount of heat can be conveyed, and the sticking of the developer can be eliminated.

In order to obtain a surface roughness Rz of 0.1 to 10 μm by the sand blasting treatment with the spherical large particles, the condition of the sand blasting treatment with the spherical large particles is dry sand blasting, the air pressure P is ^{2 to} 6 Kg / cm ² , and the injection part The distance W from the developing sleeve 3 to the surface of the developing sleeve 3 carrying the developer is 100 to 200 mm, and the particle size of the spherical large particles is 10 to 2 mm.
It is set to 10 μm. As a result, the deflection of the developing sleeve 3 during manufacturing is improved, and the sharp projections on the surface of the developing sleeve 3 which holds the developer are crushed, so that the proper transport amount is always ensured and the developer does not stick to the edges. Will be resolved. As the spherical large particles, for example, ceramic particles,
Glass particles and inorganic fine particles such as stainless steel balls and iron balls can be used.

Further, the surface roughness Rz means a 10-point average roughness as shown in FIG. 5, and the reference length L is extracted from the cross section line, and the third peak from the highest peak, The distance between two parallel lines passing through the third valley bottom from the deepest side was measured and is also expressed in μm.

[0029]

In the present invention, the surface of the developer carrying member of the developing device for carrying the developer is subjected to the unevenness forming treatment, and the method of this unevenness forming treatment is the sandblasting treatment with the irregular particles,
Further, by applying sandblasting treatment under predetermined processing conditions with spherical large particles, the fluctuation of the developer carrying member during manufacturing is improved, and the sharp protrusions on the surface of the developer carrying member carrying the developer are crushed. For this reason, even if the developer is pressed against the rigid rod-shaped magnetic member, there is no sharp protrusion on the surface of the developer carrier, so unnecessary friction with the toner is reduced and smooth regulation is performed. . Further, since the wear of the developer carrier due to the frictional force with the developer is reduced, the durability of the developer can be increased. Further, the surface of the developer carrying member becomes harder, and the durability is improved.

[0030]

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. Embodiment 1 FIG. 6 is a cross-sectional view of a main part of a developing device, in which 1 is an image carrier, 2 is a housing, 5 is a rod-shaped body (cylindrical rod) having rigidity and magnetism that regulates the amount of the developer, 15 is a cylindrical rod 5
Is a holder for holding the developer, and 6 is a spring material for allowing the developer to be conveyed from the pressing of the cylindrical rod 5 and the developing sleeve 3. The cylindrical rod 5 holds a constant load on the developing sleeve 3 without the developer intervening. Pressed with. 7 and 8 are first and second stirring members, 9 is a supply roller, 10 is a scraper, 11
Is a stirring partition plate.

The toner replenished in the developing device is sufficiently agitated and mixed with the carrier by the first agitating member 7 which rotates in the direction of the arrow and the second agitating member 8 which rotates so as to overlap each other in the opposite direction. Supply roller 9 as the upper developer D
And sent to the developing sleeve 3.

The first stirring member 7 and the second stirring member 8
Is a screw-shaped member having a left-handed helix angle that rotates 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 to the first agitating member 7 side and is conveyed to the front side of the drawing by its thrust, and the frictional electrification is performed by the mixing action of the toner and the carrier in the meantime. The developer D is attached to the peripheral surface of the developing sleeve 3 in layers by the supply roller 9 that is sponge-like and rotates in the direction of the arrow.

In this developing device, the cylindrical rod 5 is set to 6 mm
Of SUS, which has rigidity and magnetism, and the cylindrical bar 5 is located at a position facing the magnetic pole of the magnet roller 4 (2 to 6) gf / mm.
When a load of 1 was applied, a uniform and uniform transport amount of (7-9) mg / cm ² was obtained. As a result, a stable image having a uniform density was obtained. At that time, the magnetic flux density at the pressing position on the surface of the developing sleeve 3 is 600.
It was Gauss. Non-magnetic 6φ mm instead of the magnetic cylindrical bar 5
FIG. 7 compares the amount of developer conveyed with the case of using the cylindrical rod having rigidity and magnetism.

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 radius is changed can be obtained as shown in FIG. Therefore, an appropriate transport amount can be selected from this. In particular, when the radius of curvature is 0.5 to 15 mm, a stable conveyance amount in which the force exerted by the developer D on the cylindrical rod 5 and the force of the cylindrical rod 5 toward the developing sleeve 3 are well balanced can be obtained. It was More preferably, when the radius of curvature is 1 to 10 mm, the variation in the transport amount is very small regardless of the variation in the pressing force, and a uniform and thin developer layer thickness can be obtained.

Although the developing sleeve 3 having rigidity is made of non-magnetic stainless steel, the same effect can be obtained by using materials having rigidity such as aluminum metal, hard resin, glass and ceramics. Was given. The surface roughness Rz of the developing sleeve 3 is 0.1 to 10 μm.

From the above description, the surface of the developing sleeve 3 is 100 μm to 450 μm, preferably 15 μm.
A uniform and stable thin developer layer in the range of 0 μm to 400 μm is formed over a long period of time.

In this embodiment, the fixed magnet roller 4 and a thin layer of the developer material adhered on the outer surface of the developing roller 3 which rotates in the direction of the arrow (clockwise) in the developing region 12 are formed by the thin developer layer. The latent image on the image carrier 1 rotating in the indicated direction was developed in a non-contact manner at intervals to form a toner image.

FIG. 9 shows a state in which the developer layer formed in the example of FIG. 6 stands up near the developing portion. If the closest distance d between the developing sleeve 3 and the image carrier 1 and the height of the developer spikes are S, the condition of d ≧ s is satisfied in the non-contact developing method.

During this non-contact development, a developing bias containing an AC component is applied to the pre-developing sleeve 3 from a power source (not shown), so that only the toner in the developer on the developing sleeve 3 is selectively applied to the surface of the latent image. It is transferred and attached.

The developer having consumed the toner component has a high carrier ratio, is conveyed by the developing sleeve 3, is separated and collected by the scraper 10, and is mixed again with the developer having a high toner ratio.

The specifications of each constituent member of the developing device of the present invention, which is provided with the embodiment shown in FIG. 6, are as follows. The developing sleeve 3 is a thin-walled cylindrical non-magnetic stainless material having an outer diameter of 20 mmφ, and its outer peripheral surface is subjected to unevenness forming processing by two-step blasting processing. In this two-stage blasting treatment, after sandblasting with irregular-shaped particles, sandblasting with spherical large particles is carried out for molding.

The blasting conditions with less blur are shown below.

As spherical large particles, ceramic beads (A
l ₂ O _3, spherical zirconia), used as the particle size 70 to 80 m. As the blasting machine, for example, the dry method of Fuji Seisakusho is used. This sandblasting condition is
The distance between the jetting part and the surface of the developing sleeve 3 is 150m
m, the air pressure is 5 kg / cm ² , the vertical movement speed of the injection unit is 40 mm / s, the developing sleeve 3 is fixed, the rotation speed is about 30 rpm, and the processing time is 70 seconds or more.

The developing sleeve 3 thus sandblasted is rotated clockwise at 200 to 300 rpm, or 250 rpm in this embodiment. The diameter of the developing sleeve 3 is required to be a small diameter developing sleeve due to the downsizing of the developing device, but is set to 15 to 30 mmφ due to the limitation of the magnetic force of the built-in magnet roller. Various experiments were conducted on the rotation speed of the developing sleeve, but when the rotation speed is low, the amount of the carrier material supplied is small and the image density when developing the latent image is low. With respect to the developing sleeve having an outer diameter of 20 mm, the maximum image density increases linearly when the rotation speed is 0 to 200 rpm, and becomes saturated when the rotation speed is 200 rpm or more. However, the maximum image density decreases when the environmental temperature is low, so it is necessary to set it with some margin.

As shown in FIG. 6, the magnet roller 4 is composed of a magnet having 12 poles of equal magnetic poles in which N and S are alternately arranged at equal intervals.
A repulsive magnetic field is formed at a portion in contact with 0, and one pole is omitted to make 11 poles in order to facilitate the peeling of the developer, and it is included in a fixed state in the developing sleeve 3. The magnetic force of each magnetic pole is preferably large in order to suppress carrier adhesion to the image carrier 1, but there is a manufacturing limit depending on the shape of the magnet roller, and the maximum magnetic flux in the direction normal to the circumferential surface of the developing sleeve 3. Density of 500-700 gauss,
In this embodiment, it is kept at 600 gauss. Ferrite is used for the magnet roller 4.

As shown in FIG. 9, the relation between the developing sleeve 3 and the cylindrical rod 5 is a position facing the magnetic pole of the magnet roller 4, and the cylindrical rod 5 is pressed by the developing sleeve 3 and attracted by the magnetized magnetic force. Thus, the pressing force is increased and the developing sleeve 3 is uniformly contacted.

When the cylindrical bar 5 having rigidity and magnetism is used as the layer thickness regulating member in the above-described embodiment, white streaks due to developer agglomeration or toner sticking to the layer thickness regulating member in continuous copying, image quality. It was confirmed that good image quality was obtained with excellent reliability without deterioration. Further, it was confirmed that the above-mentioned effect is superior to the non-magnetic cylindrical rod in the magnetic cylindrical rod. The magnetic cylindrical rod may be magnetized and attracted to the developing sleeve 3 side, or may be magnetized and attracted as a magnet.

As can be seen from Example 1, the rigid and magnetic developer amount regulating member pressed against the developer carrying member determines the developer conveyance amount, and the rigid and magnetic cylindrical rod is used. As long as its curvature and pressing force,
Examples of various other developer layer restricting members for imparting the curvature and the pressing force may be those disclosed in JP-A-2-50184. Embodiment 2 As the developing device of this embodiment, as shown in FIG. 10, the same developing device as that of FIG. 6 is used, but the developing sleeve 3 is used.
This is an example of the case in which the rotation direction of is the same direction in the portion facing the image carrier 1. In this case, the cylindrical rod 5, which is the developer amount regulating member, is arranged at a position as shown in FIG. The developing sleeve 3 was made of non-magnetic stainless steel having a surface roughness Rz of 0.1 to 10 μm (diameter 30 mm), and the magnet roller 4 had a sleeve surface magnetic flux density of 700 gauss and 8 poles. The cylindrical rod 5 is a stainless steel SUS with a diameter of 7 mm and rigidity and magnetism.
It is arranged near the magnetic pole of the magnet roller 4 at 416, and is sandwiched and held by the non-magnetic pressing leaf spring 6 and the holder 15.

The parts of this embodiment which are not shown in FIG. 10 are constructed in the same manner as the parts of the first embodiment described with reference to FIG. The columnar rod 5 is a cylindrical magnetic body, and is a device that magnetizes the magnetic body by the magnetic field generated by the fixed magnet roller 4 in the developing sleeve 3 and obtains a pressing force by a magnetic attraction force. Since the cylindrical rod 5 presses the developing sleeve 3 with a magnetic attraction force evenly distributed in the longitudinal direction, a very good developer layer can be obtained. Third Embodiment FIG. 11 is a sectional view of a main part of a developing device showing a third embodiment.
The same functional parts as those in FIG. 6 are indicated by the same part numbers. This embodiment is an example in which a non-linear elastic body is used as the pressing member.

The developing sleeve 3 is 250 rp in the direction of the arrow.
It is a cylinder made of non-magnetic stainless steel with an outer diameter of 20 mm rotating at m, and its surface is subjected to a concavo-convex forming process by a two-step blasting process. In this two-stage blasting treatment, after sandblasting with irregular-shaped particles, sandblasting with spherical large particles is carried out for molding.

Inside the developing sleeve 3, there are fixed magnet rollers 4 with 8 poles, and the maximum magnetic flux density is kept at 600 gauss on the surface of the developing sleeve.

At the position opposed to the magnetic pole of the magnet roller 4, the cylindrical rod 5 having rigidity and magnetism is the developing sleeve 3.
Is pressed by. The cylindrical rod 5 is made of a magnetic SUS416, is a cylindrical rod with a diameter of 6 mm and is excellent in straightness, and is subjected to the graining process without a surface coating. The columnar bar 5 is restricted from moving laterally by a holder 35 attached to the housing 2, and is pressed by a non-linear elastic member 36 in the pressing direction. The non-linear elastic member used in this embodiment has a characteristic that the variation of the repulsive force with respect to the bending amount is small in the use range, and the POR has the characteristic shown in FIG.
ON is used.

In this embodiment, two linear elastic members 36 each having a thickness of 2 mm and a length of 4 × 5 mm are bonded to the holder 35, and the columnar bar 5 is pressed. FIG. 12 shows a state in which the non-linear elastic member 36 is attached to the holder 35, in which the entire length of the cylindrical rod 5 is pressed at two points divided into n: m: n = 2: 5: 2. Under such conditions, 2-4gf
When the pressing force of / mm is applied, the bending of the cylindrical rod 5 due to the pressing can be reduced, and the developing sleeve 3 can be uniformly distributed in the axial direction of 7 to 10 mg / cm ^2.
The two-component developer regulated by the developer amount was conveyed. In addition, in this example, the good developing conditions were set and maintained, even without providing an adjusting portion for regulating the amount of developer conveyed.

As the non-linear elastic member 36, in addition to PORON of urethane foam, SORBOTHA
NE (manufactured by Sandou Kosan Co., Ltd.), α-gel or the like is used, and it is also possible to use a maltoplane or a non-linear spring.

Further, the cylindrical rod 5 formed by the nonlinear elastic member 36
As for the pressing method, the pressing method based on the two-point support described in the above embodiment was effective in eliminating the bending of the cylindrical rod 5, but the pressing method based on the multipoint support or continuous support is also possible. is there. However, when such a pressing method is used, it is necessary to pay sufficient attention to the accuracy of parts and parallelism of the holder 35.

In the embodiments of the present invention, the cylindrical rod is mainly used as the developer amount regulating member, but the developer amount regulating member is not limited to these.
It is sufficient that at least the pressing portion has rigidity and magnetism and the radius of curvature thereof is 0.5 to 15 mm.

The developing conditions and developer components used in the present invention are as follows. In the developing device of the present invention, the distance between the developing sleeve 3 and the image carrier 1, that is, the value of d in FIG. 9 is 0.2 mm.
.About.0.7 mm, more preferably 0.3 mm to 0.6 mm. Decreasing the distance between the developing sleeve 3 and the image carrier 1 increases the developing electric field and increases the amount of electric force lines drawn out, so that blurring of the image during development does not occur. When the average value is 0.5 mm, the height of the brush of the developer becomes 200 μm to 450 μm by selecting the multi-pole magnet roller as described above. Therefore, the gap S between the brush tip and the latent image surface is S. -D is 0.02 mm to 0.3 mm
That is, the value corresponding to (0.1 to 0.6) × d can be maintained.

The developer used in the present invention is preferably a two-component developer. An example of this two-component developer has a particle size of 1
To 20 μm (preferably 3 to 9 μm) non-magnetic toner, and a ferrite core coated with a resin material having a particle size of 20 to 1
A developer composed of a carrier of 00 μm (preferably 30 to 60 μm) is preferably used. This toner has a toner softening point of 90 to 150 ° C. and a toner glass transition point of 2
The temperature is preferably 0 to 70 ° C. The description of this toner is as follows.

1. Thermoplastic resin (binder) (80-9
0) wt% Example: polystyrene, styrene acrylic polymer, polyester, polyvinyl butyral, epoxy resin, polyamide resin, polyethylene, ethylene vinyl acetate copolymer, etc., or a mixture thereof. Pigment (colorant) 0 to 15 wt% Example: Black: Carbon black Yellow: Benzene derivative Magenta: Rhodamine B lake, Carmine 6B, etc. Cyan: Copper phthalocyanine, sulfonamide derivative dye, etc. 3. Charge control agent 0 to 5 wt% plus toner: Nigrosine electron-donating dye, alkoxylated amine, alkylamide, chelate, pigment, 4
Mineral toner, etc. Minus toner: electron-accepting organic iron, chlorinated paraffin, chlorinated polyester, excess acid group polyester,
Chlorinated copper phthalocyanine, etc. 4. 4. Fluidizing agent Examples: Colloidal silica, hydrophobic silica, silicon varnish, metal soap, nonionic surfactant, etc. Cleaning agent (prevents toner filming on photoreceptor) Example: fatty acid metal salt, silicon oxide having organic groups on the surface,
Fluorine-based surfactants, etc. 6. Filler (improving image surface gloss, reducing raw material costs) Example: Calcium carbonate, clay, talc, pigment, etc. In addition to these materials, a small amount of magnetic powder is added to prevent fogging on the image surface and toner scattering. May be.

Such magnetic powder has a particle size of 0.1 μm.
.About.1 μm iron trioxide, γ-ferric oxide, chromium dioxide, nickel ferrite, iron alloy powder, etc. are used,
(0.1-5) wt% is contained. In order to maintain a more vivid color, it is desirable that the amount be 1 wt% or less.

Resins suitable for a pressure fixing toner which is plastically deformed by a force of about 20 kg / cm to be fixed on paper are waxes, polyolefins, ethylene vinyl acetate copolymers, polyurethanes, rubbers, etc. Resin or the like is used.

On the other hand, the surface potential on the image carrier 1 side is -600.
v, the potential of the exposed portion was 0 to −100 v, and the developing sleeve 3 was tried under the conditions that a DC bias of −500 v, an AC bias of 700 v (rms) and a frequency of 4 kHz were applied to the developing sleeve 3. It was confirmed that a high-quality toner image with well-defined gradation can be obtained with extremely high resolution.

[0063]

As described above, according to the present invention, the pressing portion of the developer regulating member for pressing the developer carrying member is made of a rigid and magnetic material having a radius of curvature of 0.5 to 15 mm, and The developer carrier is subjected to a sand blasting treatment with irregular shaped particles on the surface carrying the developer, and then subjected to a concavo-convex forming treatment to give a sand blasting treatment with spherical large particles, and the condition of the sand blasting treatment with spherical large particles is dry sand blasting. Air pressure 2-6 Kg / cm ² ,
Since the distance from the jetting portion of the spherical large particles to the surface of the developer carrying member carrying the developer is 100 to 200 mm, and the particle size of the spherical large particles is 10 to 210 μm, the surface roughness Rz0 of the developer carrying member. 0.1 to 10 μm can be obtained, the fluctuation of the developer carrying member can be improved during production, and sharp projections on the surface of the developer carrying member carrying the developer are crushed. For this reason, even if a rod-shaped magnetic member having rigidity is pressed against the developer, since there is no sharp protrusion on the surface of the developer carrier, unnecessary friction with the toner is reduced and smooth regulation is performed. . In addition, since the wear of the developer carrier due to the frictional force with the developer is reduced, the durability of the developer can be increased, and the surface of the developer carrier can be increased in hardness to improve the durability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an experiment as a 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 in the experiment of FIG.

FIG. 3 is a diagram showing the relationship between deflection and load for an example of a non-linear elastic body.

FIG. 4 is a principle diagram of a sandblast process.

FIG. 5 is a diagram illustrating surface roughness Rz.

FIG. 6 is a configuration diagram of the developing device according to the first exemplary embodiment.

7 is a diagram showing a relationship between a pressing force and a carry amount obtained by the developing device of FIG.

8 is a diagram showing a relationship between a pressing force and a carry amount obtained by the developing device of FIG.

FIG. 9 is an explanatory diagram of development between an image carrier and a developing sleeve.

FIG. 10 is a configuration diagram of a main part of another developing device according to the second embodiment.

FIG. 11 is a configuration diagram of a developing device according to a third embodiment.

FIG. 12 is a perspective view of a main part of a configuration showing a third embodiment.

[Explanation of symbols]

 1 image carrier 3 developer carrier 4 magnet roller 5 rod-shaped body 6 spring material

Claims (1)

[Claims] 1. A rod-shaped developer regulating member, which is provided inside the magnet bearing member and has rigidity, and a developer bearing member that is provided so as to face the magnet member and regulates the amount of developer on the developer bearing member. In a developing device having a body, the pressing portion of the developer regulating body that presses the developer carrying body is a material having rigidity and magnetism with a radius of curvature of 0.5 to 15 mm, and the developer carrying body. The holding body is subjected to a sand blasting treatment with irregular shaped particles on the surface carrying the developer, and then subjected to a concavo-convex forming treatment to give a sand blasting treatment with spherical large particles, and the condition of the sand blasting treatment with the spherical large particles is dry sand blasting, and air pressure is ^{2 to} 6 Kg / cm ² , the distance from the jetting portion of the spherical large particles to the surface of the developer carrier carrying the developer is 100 to 200 mm, and the particles of the spherical large particles are A developing device having a child diameter of 10 to 210 μm.