JPH08185054A - Developing sleeve having uniform and fine ruggednesses on its surface and production thereof - Google Patents

Abstract

PURPOSE: To provide the developing sleeve having uniform and fine ruggednesses on its peripheral surface, capable of forming a thin toner layer on its surface in uniform and optimum thickness and capable of providing a uniform high- grade picture. CONSTITUTION: A developing sleeve having both end shafts having a diameter smaller than the outer diameter of a circular-sectioned substrate constituting the outer peripheral surface to carry a toner layer is produced as follows. Namely, the outer peripheral surface of the substrate is machined to <=1.6μm Rz roughness in stage 3, the outer peripheral surface is further burnished to <=0.7μm Rz roughness in stage 4, and then the outer peripheral surface is sandblasted to control the roughness of the sandblasted region to 2.5±0.5μm in stage 5. The developing sleeve is produced in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing sleeve which constitutes a developing device used in an electronic copying machine, a laser beam printer or the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic method, an electrostatic latent image formed on an electrophotographic photosensitive member is developed by a developing device to be visualized. The developing device is provided with a cylindrical developing sleeve opposed to the photoreceptor, and toner (developer) is carried on the developing sleeve and conveyed to the developing position for development. For example, in the case of using a non-magnetic single-component toner that can be colorized during development, a charged toner layer is formed on the developing sleeve by charging due to friction between the developing sleeve and the blade that is the brittle member of the toner layer. But,
If the toner layer formed on the developing sleeve becomes thick, the toner layer may not be sufficiently charged, causing fog and scattering of the toner, which causes a problem that a high-quality color image cannot be obtained. Therefore, the toner layer formed on the developing sleeve is required to be a uniform thin layer. On the other hand, if the outer peripheral surface roughness of the developing sleeve becomes large, a thick toner layer is formed. On the other hand, if the outer peripheral surface roughness of the developing sleeve is too fine like a mirror surface, a thin toner layer is obtained, At the point of contact with the toner, the tribo becomes higher and the toner is less likely to be uniformly charged. In this way, the outer peripheral surface shape of the developing sleeve, particularly the surface roughness, can be obtained so that the toner layer can be uniformly charged,
In addition, it is desired to control the outer peripheral surface of the developing sleeve to have an appropriate fine uneven shape so that an appropriate thin toner layer can be formed, but there has not been enough.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to make a toner layer carried on the surface a thin layer having a uniform and optimum thickness, and a uniform color high-quality image having no unevenness. It is an object of the present invention to provide a method of manufacturing a developing sleeve capable of providing a uniform outer peripheral surface with fine irregularities, and a developing sleeve.

[0004]

The above objects can be achieved by the present invention described below. That is, the present invention provides a method for manufacturing a developing sleeve having both end shafts having a diameter smaller than the outer diameter portion of a base having a circular cross section which constitutes the outer peripheral surface on which a toner layer is carried. A step of cutting the outer peripheral surface to have a roughness Rz of 1.6 μm or less, and further performing a vanishing process on the outer peripheral surface to make the outer surface roughness Rz.
A developing sleeve having at least 0.7 μm and further performing a sandblasting treatment on the outer peripheral surface thereof to make the outer peripheral surface roughness of the sandblasted region Rz 1.0 to 3.5 μm. A manufacturing method and a developing sleeve manufactured by the method.

[0005]

As a result of intensive studies to solve the above-mentioned problems of the prior art, the inventor of the present invention develops the developing sleeve in order to form the outer peripheral surface of the developing sleeve in a uniform and fine uneven shape as described above. In the process of cutting the surface, which is performed when manufacturing
It has been found that it is sufficient to remove the periodic streaks appearing on the outer peripheral surface and finely adjust the roughness of the underlying surface to an appropriate value, and then form a uniform three-dimensional random fine uneven surface by the sandblast method. Then, the present invention was achieved. That is, in the final step by sandblasting, in order to form the three-dimensional fine uneven surface as described above, the cutting step which is the preceding step,
In the centerless grinding process or burnishing process, the occurrence of chattering, which is abnormal irregularities that occurs during cutting, and scratches that occur during centerless grinding are suppressed as much as possible. In order not to be affected by the roughness of the undercoat, the underlying surface is formed with a surface roughness as low as possible than the target surface roughness after the sandblast treatment.

Specifically, when the target image is a uniform high-quality image with an image density of 1.5 ± 0.2 and no unevenness, first the cutting surface roughness in the cutting process is set to Rz1. 6 μm
Below, the vanishing surface roughness in the next vanishing is Rz
If it is 0.7 μm or less, or if the next step is performed by centerless grinding, the centerless ground surface roughness is Rz.
The inventors have found that it is a good roughness in each step that the thickness is 1.5 μm or less and the sandblasted surface roughness after the sandblasting in the final step is 1.0 to 3.5 μm, and the present invention was completed. The above roughness is a numerical value at an axial measurement length of 2.5 mm.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to preferred embodiments of the present invention. In the first step of the method for manufacturing a developing sleeve of the present invention, the outer peripheral surface of the base body for the developing sleeve is cut by a lathe, and the outer peripheral surface roughness is Rz1.
A smooth surface of 6 μm or less is formed. This outer peripheral surface roughness is Rz
If it exceeds 1.6 μm, it becomes difficult to eliminate the cut surface roughness in the subsequent burnishing or centerless cutting, which is not preferable. For the base body for the developing sleeve, a solid columnar cylinder or a hollow cylinder having a circular cross section, for example, made of metal such as aluminum or SUS is used. In addition, it is preferable to form the shaft portion in advance by cutting both ends of the cylindrical base body to have a smaller diameter than the outer diameter before the outer peripheral surface is cut.

In the present invention, the outer peripheral surface cut in the above is further processed to make it smoother, and the surface of the sandblasted surface in the final step has an optimum uniform fine uneven surface shape, that is, Rz 1.0 to. 3.5 μm, more preferably Rz2.
0 to 3.0 μm. When the roughness of the outer peripheral surface of the sandblasting area is less than Rz1.0, the toner on the developing sleeve is less likely to be uniformly charged. on the other hand,
When it exceeds 3.5 μm, the toner layer on the developing sleeve is thickly formed, which is not preferable.

As the next step after the cutting step, specifically, centerless grinding or burnishing is performed. Hereinafter, the relationship of roughness of these steps will be described. First, in centerless grinding, a fine grindstone in which abrasive grains are randomly embedded is used. Therefore, the ground surface obtained after the treatment has a three-dimensionally uniform and random smooth surface.
In this case, the finer the grindstone used, the more the three-dimensional fine random surface can be obtained, which is preferable. However, if the grindstone is too fine, clogging easily occurs and the work efficiency deteriorates. Therefore, in consideration of maintaining the grinding ability, a grindstone is selected so that a surface having a roughness lower than the target surface roughness obtained after the final sandblasting process is formed. That is, in the present invention, since the sandblasted surface roughness after sandblasting is Rz 1.0 to 3.5 μm, the centerless ground surface roughness is preferably Rz 1.5 μm or less. This centerless ground surface roughness Rz is 1.
If it exceeds 6 μm, the roughness due to sandblasting cannot be applied uniformly.

Since the centerless ground surface is a three-dimensional random surface similar to the sandblasted surface, it is not necessary to take a large margin of roughness. On the other hand, when smoothing by vanishing, it is necessary to set it as low as possible in order to secure a margin, and preferably Rz is 0.7 μm.
It is preferably m or less. When the roughness Rz of the outer peripheral surface subjected to the vanishing process exceeds 0.7 μm, it is not preferable because the scoring of the cutting cannot be completely covered by the sandblasting process. That is, in the burnishing process, by passing the work between the mirror surface roll dies, the convex portion of the cutting surface that leaves the bite shape in the circumferential direction is plastically fluidized and crushed, and a smooth surface shape is formed by conversion. This is because it is necessary to set the cutting roughness as low as possible in order to allow a margin because it may cause chattering of abnormal irregularities.

The substrate subjected to the smoothing treatment as described above is subjected to the sand blasting treatment which is the final step to form the outer peripheral surface to a desired surface roughness. The blast surface roughness at this time is
It is determined such that a proper toner thin layer is formed so as to obtain uniform charging of the formed toner layer and a value is obtained so as to obtain a target uniform image density. The controlling factors of the blast surface roughness include the type and number of abrasive grains used, the nozzle diameter when ejecting abrasive grains, the nozzle / workpiece distance, air pressure, the work rotation speed, the blast time, etc. In order to form the surface, the influence of the abrasive grain type / count and air pressure is particularly large. Abrasive grain species include amorphous alumina / silicon carbide, spherical glass beads and the like, and spherical glass beads are particularly effective for forming a uniform fine uneven surface as in the present invention.

The preferred conditions for sandblasting used in the present invention are described below.・ Abrasive grain type (count): Glass beads (# 600 ~
# 1200) ・ Nozzle diameter: φ6 to φ8 ・ Nozzle / workpiece distance: 160 to 260 mm ・ Air pressure: 175 to 250 kPa ・ Workpiece rotation speed: 10 to 30 rpm ・ Blasting time: 25 to 55 sec By taking the above steps into consideration, Since the outer peripheral surface of the developing sleeve is processed to a uniform and optimum roughness, it is possible to stably obtain a uniform color high-quality image without unevenness by using a developing device incorporating such a sleeve. I can.

Next, an example of a developing device in which the developing sleeve of the present invention obtained by the above manufacturing method is used will be described with reference to FIG. 5, but the invention is not necessarily limited to this. In FIG. 5, reference numeral 1 denotes a developing sleeve, but the toner stored in the toner container 9 is supplied to the toner supply roller 7 by the toner stirring blade 8 in the container. Then, the toner is supplied onto the developing sleeve 1 by the toner supply roller 7, and a toner layer is formed on the developing sleeve. The toner supply roller 7 is made of a foam material such as polyurethane foam, and also removes the toner on the developing sleeve 1 after development. The toner supplied onto the developing sleeve is applied so as to form a uniform thin layer by the blade 11 which is a toner regulating member.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings to explain the present invention in more detail. <Embodiment 1> FIG. 1 shows a schematic diagram of a developing sleeve 1 according to the present invention. In this example, a solid columnar substrate is used as a sleeve substrate 2. As shown in FIG. 1, both ends of the cylindrical base body are cut to form both end shaft portions 3 and 4 having a diameter smaller than the outer diameter portion of the cylinder on which the toner layer is carried. Next, a method of manufacturing the developing sleeve 1 as described above will be described with reference to the process chart of FIG.

In this embodiment, the solid cylindrical sleeve substrate 2 is a solid cylinder of aluminum JIS A6063, but its outer diameter is 16.2 mm and the length is 2 m. (Process 1). Next, both ends of this long piece were cut with an NC automatic lathe, and as shown in FIG. 1, a shaft portion of φ8, f9 was formed at one end, and a tip portion consisting of φ8, f9 and φ6, g9 was formed at the other end. Each of the shaft parts having a step that is slightly thin is cut. Further, chamfers C0.5 are provided at both ends of the toner carrying surface of the sleeve base 2 to finish the total length to 320 mm as shown in FIG. 1 (step 2).

Next, the sleeve base body 2 having the shafts at both ends by the above-mentioned steps is held by the lathe using another lathe, and the sleeve base body 2 carrying the toner layer is held.
The outer diameter part of the outer peripheral surface of the tool bit has a tip R of 3 mm
Using a natural diamond bite, the outer peripheral surface roughness is finished to about Rz 1.3 μm (1.3 ± 0.3 μm). At this time, the outer diameter is set to φ16 ± 0.01 mm when the next process is performed by the burnishing process, and the outer diameter is set to φ16 ± 0.01 mm when the next process is performed by the centerless grinding process.
In mm, the upper limit is cut to +0.04 mm and the lower limit is cut to +0.03 (step 3). In the cutting process, it is necessary to perform the cutting process with care so that abnormal irregularities due to chattering, scratches, etc. do not occur. This is to prevent streak residue from occurring in the next step.

Next, as shown in FIG. 2, in step 4, the sleeve substrate 2 cut and processed to have a smooth surface as described above.
The surface roughness of the outer peripheral surface of the
z 0.7 μm or less to further smooth the surface shape.
The burnishing performed at this time is performed by passing the sleeve base 2 through the roll dies 5 and 5'using a rolling machine (made by Tsugami Co., Ltd.) as shown in the schematic view of FIG. As a result of such a burnishing process, the protrusions having a diameter of 2 to 3 μm were crushed, and the surface was further smoothed. Here, as described in the step 3, when the vanishing process is performed, the tolerance of the outer diameter dimension of the cutting process in the previous step is set to be as strict as ± 0.01. The reason is that if the outer diameter varies greatly, This is because the diameter portion is likely to be pressed, and fine scratches are likely to occur on the surface.

As shown in FIG. 2, when performing centerless grinding in step 4 ', a # 1000 centerless grinding wheel is used. As a result, the centerless grinding process has an outer diameter of φ16 ± 0.02 mm and an outer peripheral surface roughness Rz.
Was able to be processed to 1.5 μm or less. In addition, scratch scratches that occur in the outer peripheral direction, which is peculiar to centerless grinding, can also be suppressed. The sleeve base 2 and the both end shaft portions 3 in the developing sleeve 1 of the present invention produced by the above procedure
The deflections of Nos. 4 and 5 were 5 to 16 μm and 10 to 35 μm, respectively, with both ends of the sleeve base 2 as fulcrums.

Further, in order to uniformly coat the outer peripheral surface of the sleeve substrate 2 with toner evenly, sand blasting treatment under the following conditions was applied in step 5 to form fine irregularities on the outer peripheral surface of the sleeve substrate 2. As a result, the roughness Rz of the fine irregularities formed was 1.0 to 3.5 μm. In the present invention, the measurement of the roughness Rz value was performed with the axial length of the developing sleeve substrate 2 being 2.5 mm. The measuring method was according to JIS B0601-1982.

Sandblast treatment conditions-Abrasive grain type / count: Glass beads # 800-Nozzle diameter: φ7 mm-Nozzle / workpiece distance: 200 mm-Air pressure: 215.75 kPa-Workpiece rotation speed: 20 rpm-Blasting time: 40 sec

Each of the developing sleeves 1 obtained above was incorporated into a printer obtained by modifying the developing device of a Canon laser beam printer shown in FIG. 5, and an image output test was conducted. A high-quality color image was obtained without causing any defects.

<Embodiment 2> The manufacturing process of the developing sleeve of this embodiment will be described with reference to FIG. In this embodiment, the sleeve base 2 is a hollow cylindrical base made of aluminum A6063. The outer diameter is 16.2 mm,
Inner diameter is φ13. It is molded to H8 and a length of 269 mm (step 11). Similar to the case of the first embodiment, processed shafts having a diameter smaller than the outer diameter portion having the outer peripheral surface on which the toner is carried are provided at both ends of the sleeve base 2 by press fitting from the tip of the aluminum tube. ing. The shaft has a press-fitted diameter of φ13.05 ± 0.01 at the portion press-fitted into the aluminum tube, and the press-fitted length is 5 m.
m. The outer diameter of one end of the shaft is φ8, f9,
The other end has a stepped shape of φ8, f9 and φ6, g9 (step 12).

Next, the developing sleeve base body 2 on which the press-fitted both end shafts are formed is ground by using a through-feed type centerless grinding machine of count # 1000 (step 13).
At this time, the outer diameter of the developing sleeve substrate 2 after cutting is determined by the process 1
Φ14 ± 0.01m when proceeding to 4 burnishing
In the case of going straight to the blast treatment of step 15 in m,
Process to φ16 ± 0.02 mm. The outer peripheral surface roughness after processing was Rz 1.5 μm or less. still. The burnishing process (step 14) and the blasting process (step 15) on the outer peripheral surface of the developing sleeve substrate 2 were performed in the same manner as in Example 1.

In the developing sleeve 1 of this embodiment produced by the above procedure, the deflection of the developing sleeve base 2 and both shaft portions was 5 to 16 μm and 10 to 35 μm. When the developing sleeve 1 thus obtained was incorporated into a modified laser beam printer in the same manner as in Example 1 and an image production test was conducted, a high-quality image was obtained in substantially the same manner as in Example 1.

Comparative Example 1 A developing sleeve for comparison was manufactured by using the same solid cylindrical substrate as used in Example 1 and cutting by lathing according to the conventional method. Although the roughness of the outer peripheral surface of the obtained developing sleeve was Rz 2.0 μm, unevenness of cutting marks and the like were visually observed on the outer peripheral surface. This was subjected to the same sandblasting treatment as in the example, and the resulting developing sleeve was incorporated into the same laser beam printer as used in the example and an image output test was conducted. However, a uniform high-quality image could not be obtained.

[0026]

As described above, according to the present invention,
The roughness of the machined surface in the previous step is made smaller than the roughness of the sandblasted surface by the sandblasting in the final step where a uniform and three-dimensional random fine uneven surface is formed,
At the same time, a developing sleeve provided with a toner bearing surface having an optimum fine uneven surface is provided by forming a surface shape without abnormal unevenness due to periodic cutting marks or chattering. Further, by incorporating this in a developing device, a high quality image is provided.

[Brief description of drawings]

FIG. 1 is a schematic view of a developing sleeve according to the present invention.

FIG. 2 is a process flow chart showing a manufacturing process of a developing sleeve according to the present invention.

FIG. 3 is a schematic view showing a rolling die roll die portion for vanishing used in the developing sleeve manufacturing method according to the present invention.

FIG. 4 is a process flow chart showing another manufacturing process of the developing sleeve according to the present invention.

FIG. 5 is a sectional view of a process cartridge including a developing sleeve according to the present invention.

[Explanation of symbols]

 1: Developing sleeve 2: Developing sleeve base 3, 4, 4: Shaft part 5, 5 ': Roll die 7: Toner supply roller 8: Toner stirring blade 9: Toner container 10: Blade 11: Developing device

Claims (4)

[Claims] 1. A method of manufacturing a developing sleeve having both end shafts, each of which has a diameter smaller than that of an outer diameter portion of a base having a circular cross section which constitutes an outer peripheral surface on which a toner layer is carried. Roughness of outer peripheral surface is Rz 1.6μ
and a step of further vanishing the outer peripheral surface to make the outer peripheral surface roughness Rz 0.7 μm or less,
And a step of subjecting the outer peripheral surface to sandblasting so that the roughness of the outer peripheral surface of the sandblasted region is Rz 1.0 to 3.5 μm. 2. A method of manufacturing a developing sleeve having both end shafts, each of which has a diameter smaller than an outer diameter portion of a base having a circular cross section which constitutes an outer peripheral surface on which a toner layer is carried, and is cut on the outer peripheral surface of the base. Roughness of outer peripheral surface is Rz 1.6μ
m or less, a step of further subjecting the outer peripheral surface thereof to centerless grinding to reduce the outer peripheral surface roughness to Rz 1.5 μm or less, and further a sandblasting treatment of the outer peripheral surface thereof to the outer peripheral surface roughness of the sandblasted area. Rz 1.0-3.5
and a step of making the thickness of the developing sleeve to be μm. 3. The method for producing a developing sleeve according to claim 1, wherein the substrate has a solid cylindrical shape or a hollow cylindrical shape. 4. A non-magnetic one having a roughness of Rz of 1.0 to 3.5 μm on which a toner layer manufactured by the manufacturing method according to claim 1 is carried. Development sleeve for component toner.