JPH0336565A - Developing device - Google Patents

Abstract

PURPOSE:To add appropriate triboelectric quantity to toner by making the sharp protrusion on the surface of a recessed part blunter than that on the surface of a projecting part in a recessed and projecting part formed on the surface of a sleeve and setting a specified relation between the mean grain diameter of the toner and the diameter of the recessed part. CONSTITUTION:A developing device 3 is provided with a non-magnetic sleeve 7 which rotates on the outer side of a magnet 8. The surface of the sleeve 7 is formed to have the protruding surface which is roughed with the sharp protrusion at fine pitch by making a shapeless grain having a sharp angle collide with the surface of the sleeve 7 and to have the corrugated recessed and projecting part at large pitch by coming into collision with the shaped grain having the smooth surface, whose mean grain diameter is larger than that of the shapeless grain, and the protruding surface of the recessed part is blunter than that of the projecting part. The recessed part is formed so as to satisfy the relation of a formula I. In the formula I, d means the grain diameter of toner and X means the diameter of the recessed part. Provided that unit for both of them is mum. Thus the toner is prevented from being unevenly applied on the sleeve 7 and the appropriate triboelectric quantity is added to the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developer carrier applied to image forming equipment such as an information recording device, and a developing device equipped with the developer carrier.

[Prior Art] Conventionally, when carrying a -component magnetic developer on the surface of a sleeve-shaped developer carrier (hereinafter simply referred to as a "sleeve"), the developer is transported to a developing area. It is known that roughening the surface of the sleeve improves its transportability. As a method for roughening the sleeve surface, for example, as disclosed in Japanese Patent Application Laid-Open No. 57-66455, the sleeve surface can be roughened with amorphous tough particles (hereinafter referred to as angular powder particles) having sharp corners, such as angular powder particles. There is a method of blasting using irregularly shaped particles. This method has the advantage that the roughened surface agitates the one-component developer to bring it into an appropriate Wr electrical state, and also stabilizes the coating of the developer onto the sleeve. There is.

[Problem to be solved by the invention J.
Depends on the 6001 abrasive. When a continuous copying test was conducted using a surface-roughened sleeve that had been blasted with only amorphous particles (the same applies hereafter) and toner particles as a developer, the following phenomenon that caused the throat problem occurred. .

5000 when continuously copying in a room temperature and humidity environment
When copying a sheet, the image density decreased from 1.3 to 1.2. Furthermore, when continuous copying operation was continued in a low temperature and low humidity environment, the image density decreased from 1.3 to 1.1 when 500 sheets were printed.

In other words, it is considered that the above-mentioned decrease in image density occurs because the triboelectric charge (hereinafter referred to as triboelectric charge) applied to the toner is not sufficient. - In a low-temperature, low-humidity environment inside the shell, the toner triboelectricity tends to increase, or even in such an environment, the image density decreases as described above, indicating a lack of triboelectricity.

(B) On the other hand, a sleeve made of stainless steel (SUS: 105) was used instead of the above-mentioned irregularly shaped particles to produce fixed blast particles (hereinafter referred to as fixed particles) having a smooth surface like the spherical particles or granular powder particles of particle size well 400. ) When a continuous copying test was carried out using toner particles using a sleeve that had been blasted with only 100% of the material, the following phenomenon occurred.

5o when continuous copying operation is continued in an environment of normal temperature and humidity.
The image density was good at 1.35 when oo sheets were used. Further, when continuous copying operation was continued in a low temperature and low humidity environment, the image density was as good as 1.3 when 5000 copies were made.

However, uneven application of toner on the sleeve occurred. That is, in this case, although sufficient triboelectricity was applied, it is thought that in a low temperature, low humidity environment, triboelectricity became higher and uneven toner application occurred.

(C) Also, as in JP-A-58-11974, a sleeve made of stainless steel (CSUS: 105) with grain size #600 is used.
After blasting with irregularly shaped particles, a continuous copying test was conducted using toner particles using a sleeve that had been blasted with spherical particles, which are regular particles with a particle size of #800 smaller than the irregularly shaped particles. However, the following phenomenon occurred.

5000 when continuous copying operation is continued at room temperature
The image density was 1.3, which was good.

Further, when continuous copying operation was continued in a low-temperature, low-humidity environment, the image density was good at 1.25 after 500 sheets, but uneven toner application occurred.

Therefore, it can be seen that the lack of tribo in the case of blasting only irregularly shaped particles has been improved, or that tribo has not been suppressed in a low-temperature, low-humidity environment.

(D) Furthermore, stainless steel (SLIS: 1O5
) sleeve with irregularly shaped particles of particle size #400 similar to (A) and regular particles of particle size #400 similar to (B).
A method of blasting with particles mixed at a ratio of Although good results have been obtained with this method in terms of image density and toner application to the sleeve, it has the disadvantage that particle management is complicated. In other words, the use life is different due to the difference in strength depending on the shape and material of irregularly shaped particles and regular shaped particles, the replacement cycle is difficult to determine because the two cannot be separated, and the shape and weight of the abrasive grains , because the particle size distribution is different.

In order to maintain the mixing ratio, it is necessary to periodically perform a uniform dispersion as a mixing operation, which is not only troublesome but also causes a shortening of the life of the abrasive grains. Due to the above points, there was a problem that it was difficult to adopt it practically.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a developing device that can prevent uneven application of toner on the sleeves, provide an appropriate amount of triboelectric, and obtain a stable image regardless of the environment. do.

[Means for Solving the Problems] According to the present invention, the above object is to provide a developing device equipped with a developer carrier having an endlessly movable surface while carrying a developer. Is the protrusion surface roughened with sharp protrusions at a fine pitch by colliding irregularly shaped particles with sharp edges?

The above-mentioned protrusion surface is formed to have wavy irregularities with a large pitch due to the collision of regular particles having smooth surfaces with an average particle diameter larger than the average particle diameter of the irregular-shaped particles. The developer is also blunted in the recess, and the recess has a particle size d (micrometer) of the developer.
This is achieved by forming the relationship between and the diameter of the recess x (micrometers) as follows: 40<dXx''2<20O.

[Function] As described above, in the present invention, the protrusion surface of the convex part of the concavo-convex part formed on the sleeve surface is sharper than the surface of the concave part, so that the frequency of contact with the toner is reduced, and triboadhesion is reduced.
Since the sharp protrusions on the surface of the concave portion are blunted compared to the surface of the convex portion, the frequency of contact with the toner is increased, and the triboform is actively applied. Therefore, the amount of tribo added to the toner should be appropriate.

Furthermore, the average particle diameter d (μ dust) of the toner and the diameter f of the recessed portion
As a result of investigating the relationship between %x (+ eyes), 40<dX x”
If it is set so that 2<200, the smaller the average particle size of the toner, the larger the diameter of the recessed portion will be. Therefore, the average particle size of the regular particles used to form the recesses is increased, and as a result, the number of regular particles that collide per unit area of the sleeve surface is reduced.
- The ratio of the area of the recess to the surface of the projection h is reduced. In other words, for small-diameter toner that tends to obtain high tribo, the ratio of the concave portions is reduced to suppress tribo. Conversely, the larger the average particle size of the toner, the smaller the diameter of the concave portions. Therefore, the average particle size of the regular particles is reduced. Therefore, the number of regular particles colliding per unit area of the sleeve surface increases, and the ratio of the area of the recess to the surface of the protrusion increases. Thus, for large-diameter toner particles that tend to have low triboelectricity, the proportion of the recessed portions is increased to positively impart triboelectricity. In such a relationship, 4
It has been found that if d

[First example] The present invention will be described in detail below based on the accompanying drawings.

FIG. 1 is a schematic diagram of an image forming apparatus having a developing device as a first embodiment of the present invention.

In the figure, 1 is a latent image holding member (usually a photoconductor (hereinafter referred to as "photosensitive drum")), 2 is an electrostatic latent image forming section, and 3 is H
A developing device for converting the I image into a visible image, 4 a transfer separation unit for transferring the visualized toner image on the photosensitive drum to a transfer material, and 5 a cleaning unit for cleaning residual toner on the photosensitive drum. It is.

Such an image forming apparatus functions as follows.

First, a latent image is formed on the photosensitive tram l by the electrostatic latent image forming section 2. Further, the photosensitive drum 1 rotates in the direction of arrow A and reaches the developing device 3 in the area where the latent image is formed. The developing device 3 includes a hopper 1 which is a container for storing toner.
o, a stirring means 9 that sends the toner from the hopper 10 to the vicinity of the sleeve 7 serving as a developer carrier and improves the fluidity of the toner, a fixed magnet 8, and further rotates the outside of the magnet 8. Although a non-magnetic sleeve 7 is provided, the present invention is not limited thereto.

Further, the thickness of the toner layer on the sleeve 7 is the same as that of the opposing magnetic pole N1.
It is regulated by a magnetic blade 6 which also regulates it.

On the sleeve 7, the toner stands in spikes due to the developing magnetic pole Sl at a position facing the photosensitive drum 1, and the sleeve 7 is caused by an electric field (preferably an oscillating electric field such as AC) between the latent image on the photosensitive drum 1 and the sleeve 7. The upper toner flies to the photosensitive drum 1 and becomes a visible image. At this time, a developing bias (direct current may be used, but in this case, an alternating electric field) is applied to the sleeve 7 at bias '[i 11] so that the toner can easily fly. The imaged toner image on the photosensitive tram 1 is transferred to a transfer material (not shown) in a transfer separation section 4, and the toner image on the transfer material is fixed by a fixing film (not shown). On the other hand, the surface of the remaining toner on the photosensitive todium 1 is cleaned by a cleaning section 5 in preparation for the next latent image formation.

Next, the magnet and sleeve in the above-described particular image forming apparatus will be explained.

First, the magnet 8 is a cylindrical body with various magnetic pole strengths shown on the surface of the sleeve 7, N+: 1000 [gaussl
, S, :1o00 [gaussl, N, :750 [g
The shortest gap between the sleeve 7 and the photosensitive drum 1 was 0.25 mm, and the shortest gap between the sleeve 7 and the magnetic blade 6 was 0.25 mm. Also, as a bias power supply 11,
AC with a voltage V□ (peak-to-peak) of 1400 V and a frequency f of 1800 Hz.
Developing was carried out by superimposing 120 V DC on the image forming apparatus, and copying was performed at a speed of 80 sheets per minute on A4 size paper. Further, the photosensitive drum 1 was set to be ^-3i, and the dark area potential was set to 40V1, and the bright area potential was set to 70V.

The material of the sleeve 7 is stainless steel (5US305).
The outer diameter was set to 32 m and its surface was blasted. The sleeve 7 may be made of stainless steel, aluminum, or titanium steel.

In this example, the blasting conditions for the sleeve surface were as follows: irregularly shaped particles (
Particles with sharp edges such as angular powder particles) $40
12rp using A411.03 with an average particle size of 35 to 45 IL (according to the JIS R6001 abrasive particle size standard. Hereinafter, the particle size will depend on the particle size standard.)
A nozzle with a diameter of 7 mm located 150 mm away from the sleeve generates an air pressure of 3.5 m.
kg/cm" for 30 seconds, and the nozzle is moved back and forth parallel to the axis of the sleeve over a distance of 30C. After that, the sleeve surface is cleaned and dried in the cleaning process. At this time, the surface roughness of the sleeve is As shown in the figure.

Furthermore, after that, glass beads (FGB) of #100 (average particle size 150 to iao μm) were used as regular particles (spherical particles or particles with smooth surfaces such as granular powder particles), and the treatment time was set at an air pressure of 3.0 kg/cm. Blasting was carried out for 30 seconds under the same conditions as for the amorphous shape.

After that, the cleaning process was carried out as described above. FIG. 3 shows the surface roughness of the sleeve of this embodiment.

Next, a developing device using the above-mentioned processing method and an average particle size of 11 pm were used.
(Volume average value determined by the Coulter Counter method. The same applies to the toner particle size hereinafter.) When copying was performed using magnetic toner, there was little variation in density during intermittent copying and continuous copying, and there was no change at room temperature and humidity. Also about 1
．． An image density of 35 was obtained. Further, an image density of 1.3 was obtained in all cases under low temperature and low humidity conditions, and there was no occurrence of uneven application of toner to the sleeve surface.

When the surface of the sleeve after the above treatment was observed, the following structure was confirmed on the surface. That is, approximately 70% to 80% of the finely blasted surface is made of irregularly shaped particles.
The diameter is 40JLm to 5% due to the thick regular particles in the area.
It was confirmed that a recess of 0ILm was formed and that the fine mesh of irregularly shaped blast was preserved in the recess. Many sharp microprotrusions were observed on the 20% to 30% portion of the amorphous blast surface that was not impacted by the regular particles, but on the 70% to 80% portion that was impacted by the regular particles. The surface was slightly smooth with sharp microscopic projections. This indicates that while this surface maintains fine protrusions, there are also parts with different sharpness.

Next, experimental examples (1) to (4) conducted based on the first embodiment will be explained. Each of the experimental examples ① to ② was compared with the first example by changing the particle size of the regular particles. The basic conditions are the same as in the first embodiment.

<Experimental example ■> In this experimental example, glass beads of #400 (average particle size 40 to 50 IL), which have the same particle size as the amorphous particles, were used as the regular particles in the blasting process, and other blasting conditions and the configuration of the developing device were used. is the same as the first embodiment. When I made continuous copies (sooo many copies) under the above conditions, the image density was at room temperature and humidity! , 35, under low temperature and low humidity 1.
It was 30. Moreover, uneven toner application to the sleeve did not occur. When the surface of the sleeve used at this time was observed, it was found that the metallic luster had increased slightly, although it appeared to be in the same condition as when only the irregular shape blasting treatment had been performed. Looking more closely, it was found that approximately 90% of the irregularly shaped blasted surface had evidence of collision with regular particles, and the diameter of the recesses was approximately 20 to 30 l. It was also found that the surfaces of sharp protrusions in the recesses were smoothed due to irregular shape blasting.

On the remaining 10% of the surface, there were sharp microscopic protrusions that are unique to irregular-shaped blasting.

<Experimental Example ■> This experimental example differs from the first experimental example in that glass beads of $700 (average particle diameter of about 251 Lm), which are smaller in diameter than the irregular particles, are used as regular particles. Other blasting conditions and the configuration of the developing device are the same as in the first example.When continuous copying was performed using this experimental example device, the image density was 1.35 at room temperature and normal humidity, and at low temperature and low humidity. It was 1.30. However, uneven toner application to the sleeve occurred.

When the surface of the sleeve used at this time was observed, it was found that the metallic luster had increased compared to the #400 glass beads of the first experimental example. Looking more closely, there was evidence that regular particles had collided over almost the entire area of the irregularly shaped blasted surface, and the diameter of the recesses was approximately 5 to log m. It was also found that there were some parts of the recesses where the sharp protrusions had been smoothed by the irregular blasting process.

<Experimental Example ■> This experimental example differs from the first experimental example in that glass beads of #30 (average particle diameter of approximately 6001 Lw), which have a larger diameter than the irregularly shaped particles, were used as the regular particles. Other blasting conditions and the configuration of the developing device were the same as in the first example. When continuous copying was performed using this experimental example device, the image density was 1,30 at normal temperature and normal humidity, and 1,30 at low temperature and low humidity.
It was 1.25. Moreover, uneven toner application to the sleeve did not occur. When the surface of the sleeve used at this time was observed, it was found that approximately 30% of the irregularly shaped blasted surface had evidence of collision with regular particles, and the diameter of the recesses was approximately 150 to 100 mm.
20 (1% ■). It was also found that the sharp protruding surfaces in the recesses due to the irregular shape blasting process Jl were smoothed. The remaining approximately 70% of the surface was coated with the irregular shape blasting process unique to the irregular shape blasting process. Sharp microscopic projections were present.

(Experimental Example ■) This experimental example differs from the first experimental example in that glass beads with a diameter of 10 (average particle size of about 1700 gm), which is larger than the irregularly shaped particles, are used as the regular particles.

The other blasting conditions and the configuration of the developing device were the same as in the first embodiment. When continuous copying was performed using the experimental device, the image density per image was 1.20 at room temperature and humidity.
Under low temperature and low humidity conditions, it was 1.15, which was the same decrease as in the case of only amorphous thrust treatment. Moreover, uneven toner application to the sleeve did not occur. According to the surface of the sleeve used at this time, approximately 10% of the irregularly shaped blasted surface
There was evidence that regular particles had collided with each other, and the diameter of the recess was approximately 400 to 500 μι. It was found that the sharp protrusion surfaces in the recesses were smoothed due to the amorphous blasting process. On the remaining 90% or more of the surface, there were sharp microprotrusions unique to irregular-shaped blasting.
Table 1 shows the results of Example 1 and Experimental Examples (1) to (2). Note that the regular blast region is the region where the regular particles collided.

From the above experimental examples from ■ to ■, the most suitable range for the toner particle size or the size of the recess when the average amount is 11μ is 40 to 80g.
It turned out to be m.

Regarding the particle sizes of irregularly shaped particles and fixedly shaped particles, it has been found that better results can be obtained when the particle size of the fixedly shaped particles is larger than that of the irregularly shaped particles.

Furthermore, the area where the regular particles collide (standard blast area) is preferably 10% or more and 90% or less, and in order to obtain good image density and toner application results, the sleeve surface properties are such that some parts have sharp fine protrusions. It was found that there were some fine protrusions that were blunted.

If the entire surface of the sleeve has been blunted or has only been shaped, the contact between the toner particles and the sleeve surface will be active, and the toner triboelectricity will increase. It is thought that if some toner particles are present, they will be adsorbed to the sleeve surface by reflection force, making it difficult for them to fly during image formation, and this will cause uneven toner application. In addition, the sleeve surface, which has only sharp micro-protrusions on the entire surface, easily captures toner particles mechanically, which prevents the movement of toner particles, reduces the frequency of contact between the sleeve and toner, and provides sufficient triboelectricity to the toner. It is considered that this is not possible. Therefore, it is considered that the regular blasting (overlapping treatment) after the irregular blasting has both the function of imparting triboelectricity to the toner particles and the function of preventing excessive triboelectricity.

[Second Example] Next, a second example of the present invention, which was carried out to investigate the relationship between toner particles and the size of the recessed portion, will be described. The present invention uses #3o glass beads as regular particles, which corresponds to Experimental Example (2), or uses a magnetic toner with a particle size of 5μ, which is smaller than that used in Experimental Example (■), as a toner. This is different from Experimental Example (2) (in Experimental Example (2), a toner with a particle size of 11 kLm was used), except that the copying operation was carried out under the same conditions as in the first Experimental Example (2). In addition,
The diameter of the recess is 150 to 200 mm. In Peng, the regular thrust area is 30%.

As a result, there was little density variation in intermittent copying and continuous copying, and the image density was 1 and 5 at normal temperature and humidity, and 1.30 at low temperature and low humidity, which was better than experimental example ①. Even at low temperature and low humidity, toner application to the sleeve was uneven and good.

Next, experimental examples ① to ＠ in which the particle size of the regular particles was changed based on the second example will be explained.

<Experimental example ■> In this experimental example, #400 particles with the same diameter as the irregularly shaped particles were used as regular particles.
This embodiment differs from the second embodiment in that glass beads are used.

In this experimental example, which was subjected to blasting under the same processing conditions as in the second example, the particle size of the regular particles was the same as in experimental example (2). This blasting process (the diameter of the recess is 20 to 30
In μm, the regular blast area is 90%. ) was used to perform copying operations under the same conditions as in the second example. As a result, in intermittent copying and continuous copying, there was little variation in density, and the image density was 1.35 at room temperature and normal humidity, and 1.35 at low temperature and low humidity. Both results were 1.30, which was the same as in Experimental Example (2).However, the difference from Experimental Example (2) was that uneven toner application to the sleeve occurred under low temperature and low humidity conditions.

<Experimental example■> In this experimental example, #l, which has a larger diameter than irregularly shaped particles, is used as a regular particle.
This embodiment differs from the second embodiment in that O glass beads are used. Blasting was carried out under the same conditions as in the second example. In this experimental example, the particle size of the regular particles is the same as in experimental example ①. This blast place J! ! (The diameter of the recess is 400
At ~500 gm, the shaped blast area is less than 10%. ) Copying was performed using the sleeve under the same conditions as in the second example, and as a result, there was little variation in density during continuous copying, and the image density was 1.35 at room temperature and humidity, and 1 at low temperature and low humidity. .30, a better result than Experimental Example ① was obtained, and uneven toner application to the ° sleeve did not occur under low temperature and low humidity conditions.

The above results are shown in Table 2.

As is clear from Table 2, it was found that the most suitable diameter of the concave portion was in the range of 150 to 200 μm when the average toner particle size was 5 μm. Moreover, as a result of further similar experiments, it was found that a range of 100 to f50 p,m is suitable.

Next, a third example will be described in which the relationship between the toner particle size and the diameter of the recessed portion was investigated in more detail.

[Third Example] In this example, the average particle size of the toner used was 15IL11.
#800 irregularly shaped particles.

This example differs from the first and second examples in that #40 size particles were used as the regular shaped particles. Further, the diameter of the concave portion on the sleeve surface of this embodiment is 20 to 30 IL (2), and the regular blast area is 90%, which is the same as in Experimental Example (2) and Experimental Example (2).

When intermittent copying and continuous copying were performed using the sleeve according to this example, image densities of about 1.35 were obtained in both cases at room temperature and normal humidity with little variation in density, and in both cases at low temperature and low humidity. An image density of .30 was obtained. This result was similar to Experimental Example (2) and Experimental Example (2). Also,
There was no occurrence of uneven toner application on the sleeve surface under low temperature and low humidity conditions, and better results were obtained than in Experimental Example ①.

Next, experimental examples (1) to (4) conducted based on the third embodiment will be explained.

<Experimental Example ■> This experimental example differs from the third example in that #700 glass beads were used as the regular particles. Blasting was carried out under the same conditions as in the third example. In this experimental example, the particle size of the regular particles is the same as in experimental example (2). When copying was performed using a sleeve that had been subjected to such blasting (the diameter of the concave portion was 5 to 10 mm, and the regular blast area was approximately 100%), density fluctuations were observed during intermittent copying and continuous copying. The image density was 1.35 in both cases at room temperature and normal humidity, and 1.30 in both cases at low temperature and low humidity, which was the same as in Experimental Example ■, but uneven toner application to the sleeve occurred under low temperature and low humidity conditions. However, better results were obtained than in Experimental Example ■.

Experimental example ■〉 In this experimental example, #30 glass beads were used as regular particles, and blasting was performed under the same processing conditions as in the third example. This corresponds to the example. Such blasting treatment (the diameter of the recess is 150-200 ILw.

The regular blast area is 30%. ) was used to perform copying operations under the same conditions as in the third example, and the image density was 1 at room temperature during continuous copying.
．． 20. The result was 1.15 under low temperature and low humidity, which was worse than Experimental Example ① and the second example, but there was no occurrence of uneven toner application to the sleeve under low temperature and low humidity.

The above results are shown in Table 3.

From the above experimental examples ■~■, the most suitable range for the size of the recess is a 20~30μ layer when using 15p■ toner, and the results of further similar experiments revealed that the size of the recesses is 20~30μ layer.
It has been found that good results can be obtained within this range.

The above first to third examples and experimental examples ■ to ■
Figure 4 is a graph summarizing the results up to this point.

From the results shown in Fig. 4, the relationship between the toner particle size and the size of the recess is 40<d, 7<200, which is usable, and 7o<a, rma<100, which is more preferable. It turned out that it was.

It was also found that when processing time and air pressure were fixed, the use of a sleeve finished with smaller regular blast particles resulted in higher triboelectricity than the case with larger regular blast particles. The reason for this is that the smaller the regular particles are, the more particles collide per unit area, and the area of the regular blasting section increases.

When using large particles, by increasing the processing time, you can obtain the same fixed blast area as with small particles, but it is less efficient; on the other hand, if the particles are too small, the fixed blast area tends to be too large, and The process is the same as that of chisel and causes uneven toner application. Therefore, if the processing time and air pressure are the same, and if a small toner that is prone to high triboelectricity is used, it is better to use larger regular particles.

In addition, the first to third examples, and experimental examples ■ to ■
As is clear from the results, it was found that the area where the regular particles collide (the regular blast area) is preferably 10% to gO%.

Experimental Example■> As mentioned above, when the processing time and air pressure are fixed, is it possible to change the blast area by changing the particle size of the regular particles? , the blast area can also be changed by changing the air pressure (injection pressure). In order to confirm this, the following experimental example (2) was conducted. In this experimental example, the same particles as in the first example were used, in which the irregularly shaped particles had a particle size of #400 and the regular shaped particles had a particle size of #100, and the injection pressure was changed from 3.0 kg/cm'' to 5.0 kg/cm''. c.
The comparison was made using m2.

As a result, the recess expanded from about 501 Lm to about 120 μm, and the plastic area became almost 100%. This is because, as shown in FIG. 4, this is a usable area.The bumping portion was a completely smooth surface, and uneven toner application occurred under low temperature and low humidity conditions. In this way, the blast area could be changed by the injection pressure, or if the injection pressure was too high, the protrusion surface would be completely smoothed and good results would not be obtained.

As described above, it is clear that in order to obtain good results in image density and toner application, it is necessary to maintain an appropriate level of toner triboelectricity by leaving a slightly dulled fine protrusion area without making the recesses completely smooth. .

However, in the case of toner with a particle size of more than 15 μm, scattering became noticeable in the fine line portions of the copied image, causing density unevenness. This is because the surface area of the toner is large, making it difficult to provide uniform triboelectricity to each toner, and the toner particle size itself is too large. In addition, toner with a particle size of less than 4 mm has poor production efficiency, gets into the fibers of current plain paper, and is difficult to fix. Since it is difficult to manufacture in terms of properties, a toner having a particle size of 4 to 51 Lm is preferable.

In addition, as irregularly shaped particles, use any one of silicon carbide particles, alumina particles, iron trioxide particles, and titanium dioxide particles, and as fixed particles, use any one of glass beads, steel balls, ferrite balls, and flat ferrite particles. However, it is not limited to these.

In addition, the developer carrier is not limited to a cylindrical one;
A cylindrical type or a belt type can be used, and a roller of the magnet itself can also be used.

Furthermore, in the above-described embodiment, a developer layer that is thinner than the gap between the sleeve and the drum is conveyed to the developing section, but in the present invention, a developer layer that is equal to or thicker than the gap between the sleeve and the tram is conveyed to the developing section. It can also be applied to equipment.

[Effects of the Invention] As explained above, according to the present invention, the outer surface of the sleeve is finely roughened using irregularly shaped particles, and furthermore, the irregularly shaped particles are caused to collide with each other to make the surface of the protrusions of the convex portions rougher. By forming a concave portion having a roughened protrusion surface, sharp protrusion surfaces and blunt protrusion surfaces coexist, thereby making it possible to impart appropriate triboelectricity to the toner. Therefore, by incorporating the developer carrier of the present invention as a developing sleeve, it is possible to reliably transport the developer and maintain the developing ability over a long period of time, and it is possible to always maintain good images even during continuous copying operations without causing uneven toner application. It is possible to provide stable images regardless of the environment.
(Margin below)

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the apparatus of the first embodiment of the present invention, FIG. 2 is a diagram showing the surface of the developer carrier of the first embodiment apparatus treated with only irregularly shaped particles, and FIG. FIG. 2 is a diagram showing the surface of the developer carrier treated with regular particles, and FIG. 4 is a diagram showing the relationship between the average particle diameter of the toner and the diameter of the smoothed recesses as a result of the second experimental example. 3...Developing device

Claims (5)

[Claims] (1) In a developing device equipped with a developer carrier having an endlessly movable surface while carrying developer, the surface of the developer carrier is finely divided by colliding amorphous particles with sharp corners. The protrusion surface, which is roughened with sharp protrusions at a large pitch, becomes wavy and uneven at a large pitch due to the collision of regular particles with a smooth surface and an average particle diameter larger than the average particle diameter of the irregularly shaped particles. The surface of the protrusion is more blunted in the recessed part than in the convex part, and the recessed part has an average particle diameter d (micrometers) of the developer and a diameter x (micrometer) of the recessed part. A developing device characterized in that the relationship is such that the product of the square root of the diameter x of the recess and the particle size d is greater than 40 and less than 200. (2) Claim (1) wherein the smaller the average particle size of the developer used, the larger the average particle size of the regular shaped particles.
The developing device described in . (3) The developing device according to claim 1, wherein the average particle size of the regular particles is larger than the average particle size of the irregular particles. (4) The developing device according to claim 1, wherein the developer has an average particle size of 4 to 15 micrometers. (5) The developing device according to claim 1, wherein the region in which the regular-shaped particles collide is an area that is 10% or more and 90% or less of the surface of the protrusion formed by the irregularly-shaped particles.