JPH039376A - Manufacture of electrostatic charging roller - Google Patents

Abstract

PURPOSE:To perform uniformly surface roughening in a short time and to obtain an excellent image with no irregularity, ground staining, lateral stripe formation, etc., by performing the surface roughening processing while making the relative roughening speed to a blank electrostatic charging roller abutting surface in the beginning different from that after the roughening. CONSTITUTION:When the surface of the electrostatic charging roller 11 is roughened by using a beltlike abrasive material 12, the relative polishing speed of the abrasive material 12 to the abutting surface of the electrostatic charging roller 11 is fast in the beginning, and then reduced thereafter. For example, the relative roughening speed defined by the difference between the linear speed of the surface of the electrostatic charging roller 11 and the moving speed of the beltlike abrasive material 12 is set to a fast-side range of 500 - 5,000 mm/sec and a low-speed side of 1.0 - 200 mm/sec. Consequently, a uniform surface roughened state is realized in a short time, there is neither the staining of a white part of an image due to an irregularity of electrostatic charging nor the ground staining of the image due to the sticking of toner on the electro static charging roller, and a copy image of high quality is stably obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a charging roller used in electrophotography X*a.

[Prior Art] Until now, five photoconductive materials used in electrophotographic photoreceptors have been
Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are known. These photoconductive materials have many advantages, such as being able to be charged to an appropriate potential in the dark, having little charge dissipation in the dark, or rapidly dissipating charge when irradiated with light. On the other hand, it has various drawbacks. For example, a selenium-based photoreceptor,
Crystallization easily progresses due to factors such as temperature, humidity, dust, pressure, etc., and especially when the ambient temperature exceeds 40° C., crystallization becomes severe, resulting in disadvantages such as a decrease in charging property and the appearance of white spots on images. Cadmium i-chloride photoreceptors do not provide stable sensitivity in humid environments, and zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as rose bengal. It has the disadvantage that it cannot provide stable images over a long period of time because the sensitizing dye deteriorates due to charging and photofading due to exposure light.

On the other hand, it has been discovered that certain organic compounds exhibit photoconductivity. Examples are organic photoconductive polymers such as poly-N-vinylcarbasol, Borich'nylanthracene, etc., carbazole, an!・In addition to low-molecular photoconductors such as helices, pyrazolines, oxadiazoles, pyrazolines, and polyaryl alkanes, FujiD cyan pigments, ammonium pigments, cyanine dyes, polycyclic A, and Pigments, beri1/n type face stains, indigo dyes, thioindigo dyes,
Organic pigments and dyes such as methine dyes and squaric alcohol dyes are known, and especially organic pigments and dyes that have photoconductivity are easier to synthesize than S-type materials, and may be able to absorb light in an appropriate wavelength range. Many proposals have been made, including the expansion of variations that allow selection of conductive compounds. For example, U.S. Q4 Permit No. 412:1270,
No. 51613, No. 4251614, No. 42568
No. 21, No. 4260672, No. 4268596, No. 4278747, No. 4293628, etc., in a photosensitive layer separated into a charge generating/J- layer and a charge transport layer. A glossy photoreceptor using a disazo pigment exhibiting photoconductivity as a charge-generating substance is known.

Conventionally, most of the charging processes involved in this process have been performed by applying a high voltage (DC 5 to 8 kV) to a metal wire to generate an N charge. But this one! In humans, when the corona occurs, ozone, No, etc. τ1) Nino [Suna products change the surface of the photosensitive body 1'! Is the image blurring or deterioration progressing, or is the wire dirty? There were some problems with the quality of the 1Ill image, such as white spots and black lines appearing in 1 image when engraving. ~ On the other hand, in terms of electric power, the current flowing to the photoreceptor is -30% to 5.
Most of the time, it is treated as a shield, and it is inefficient as a 1st stage of charging.

In order to compensate for these 17. disadvantages, the conventional
! Many researches have been done on methods to do this, and many have been proposed.
, 58-4056Fl, 5813915[i,
58-150975, etc.) These include the shape of the direct charging member and the shape of the roller, brush (including magnetic brush), plate, belt, etc., and the specifications of the electrophotographic device (S-Selected as well). iIT is capable.

However, in the 1-roller charging method, i, l: O rona charging and W, the charging member and the photoreceptor
Since the tram (sometimes abbreviated as ``ram'') has a direct contact with the tram, there is a problem that the charging roller tends to stick to the tram, and that the tram tends to be unevenly charged. li using the charging port ~ sea! In the I contact method, the drum and 'N-N-
- If the distance between the rollers is constant, sometimes an electric discharge occurs and voltage is applied to the drum. It is likely to be uneven or 7.

Also, if the surface of the charging roller is flat, it will be easier to use for repeated images.
), the toner adhered to the charging roller and caused background stain J1 on the image.

[Problems to be Solved by the Invention] The first object of the present invention is to prevent stains on the white background of images due to non-uniform charging and to prevent stains on the charging ports, etc., in electrophotographic apparatuses using charging rollers. The object of the present invention is to develop a charging roller for an electrophotographic device that can stably supply high-quality copy images without causing background smudges on images due to toner adhesion to the surface.

The purpose of item F can be achieved by providing unevenness on the surface of the electrically charged low-sea surface with an average surface roughness of -f: from 0.3 μl to 5.1 jp-s. The inventors of the present invention have already proposed this, but it is still difficult to control the roughness of the surface, which causes uneven charging. In addition, there is a drawback that it takes a long time to uniformly roughen the surface.6Therefore, a second object of the present invention is to uniformly roughen the surface of the cable charging roller.
This objective is achieved by initially increasing the relative surface roughening rate of the belt-shaped abrasive material with respect to the surface in contact with the charging roller, and then decreasing it thereafter.

[Means to solve the problem] The present invention will be explained in more detail below.

The material of the charging roller used in the present invention is metal such as aluminum, iron, copper, etc., conductive polymer material such as polyacetylene, polypyrrole, polyethylene, carbon, etc.
Rubber, artificial fiber or polycarbonate treated with R-electrification, polyvinyl acetate (1-), polyvinyl acetate (R), artificial fiber or polycarbonate (without dispersing metal, etc.),
It is also possible to use an insulating material such as polyester whose surface is coated with metal or other conductive material. The volume resistivity of these conductive members is 109゛-10]2Ω-cs+, optimally Ifl'-, 1010
Ω・cP range 'C Charging port - Sea surface is not roughened 117th condition 1
The image quality is improved using the charging roller and photoreceptor 1-ram.
When this is done, the charging roller (~): photoreceptor drum or the like (-)
Easy-to-use two-pronged charging roller (with toner R'1-
There is also a high probability that Is the surface of the charging roller flat?

Therefore, during discharge, it is easy to pick up defects (unevenness and distortion) on the ram (1), and it is easy to cause uneven charging.

For the following reason, the charged l'I-Rashi surface is raised to 17
The surface becomes rough 2′> Kotoka Shinka”τan).

For 42 roughening methods υ= and 1, mechanical polishing or superior tlr
However, a method using a band-shaped abrasive material is more preferable. The reason is that in the case of soundtrack last, υ:, etc., V′ζ:
;1. Abrasive material or charging roller -r- easy to get stuck?
In contrast to the cause of Fi electric unevenness:・σ), in the case of band-shaped abrasive material, this is because there is almost no embedding.

1. However, the roughening method still does not roughen the surface to the point where it has a low electrostatic charge.
The phenomenon that it is difficult to charge uniformly during charging due to the talent 1 has not been solved yet. Another drawback was that it required a much longer time to uniformly roughen the surface.

As a result of careful study on roughening the surface of the charging roller, the inventors of the Wooden Society have found that in a method of roughening the surface of the charging roller using a band-shaped abrasive material, the charging roller of the abrasive material is By initially increasing the relative polishing ball Ig to the contact surface and then decreasing it, the total grain surface roughness, average surface roughness, and minimum surface roughness can be adjusted to 0.3.
As a result of achieving a uniform surface roughness in the range of 5.0 mm LWPl in a short time, uneven charging can be almost eliminated.6 Here, T2 maximum surface adhesion, average surface roughness ζq facet Roughness refers to the maximum value, average value, and minimum value obtained by measuring the upper point average roughness (R2) defined in JNS JjJ, Case BO310.

That is, the present invention provides a method for roughening the surface of a charging roller using a belt-shaped abrasive material, in which the relative speed of the belt-shaped abrasive material to the contact surface of the charging roller is initially large, and then the I 4. In the method of roughening the surface of the CC electric roller using a band-shaped abrasive material, in the early stage of the roughening of the surface of the charging roller, :, the machinability of the surface is reduced. low. However, after the surface has been roughened to a certain extent, the abrasive particles of the abrasive material tend to catch on the unevenness of one surface, resulting in a scraped product. If the relative surface roughening speed is set at a low level, the surface roughening progresses quickly, but problems arise when the surface roughness is controlled. It can be difficult to progress or it can be progressed evenly. In view of these two points, the essence of the present invention is to set the relative surface roughening speed 1/ to a large value at the beginning W1 and to reduce it later.

How to prevent it from occurring In case of implementation, please refer to the example and 1. /
-τ It is possible to use the first saddle n, which is schematically shown in cross section in FIG.

Rotate the basic charging roller around gf at 11 o'clock.

- Force, band-like? i! f polishing material i7$;i 1 while pushing out, mouth, - sea 13h, etc.? The charging port 11 is connected to the polishing hole 2i by pressing large roller X4!
,・move in the direction of the arrow 16 toward the τ winding percentage take-up roller 15. At this time, the belt-shaped abrasive material 12 is charged by pressing the pressure roller 14 into the charged position. Rub the surface of 1. In the Kokusei JjJ method, the relative surface roughening speed defined as the difference 'e between the linear velocity of the surface of the charging port -RA-13 and the moving speed of the belt-shaped abrasive material 12 is 1.0-, -50.
Set the following two steps within the range of 7 seconds for 00 (0
In the initial stage of surface roughening, surface roughening is performed on the high speed side. The high speed side is 50 (1”-500i m/s, preferably 1
000~5000mm/sec, Q) Medium ml for roughening
In the meantime, the surface can be roughened on the far side, the color,
The far side is 1.0 to 2 [tOm/sec, preferably 1.0
~1oOL!岨 / seconds, here, belt-shaped polishing,! When applying the abrasive material obliquely to the generating line of the large charging port 4 or 11, the minute speed in the rotation direction of the charging roller is used as the speed of the abrasive.

In the present invention, the initial process from the beginning of surface roughening 11J to the time when the sliding resistance against the strip-shaped abrasive material changes almost suddenly takes 7 minutes, and usually ends within one minute at the longest.

The band-shaped abrasive material used in the practice of the present invention includes aluminum oxide, silicon carbide, chromium oxide, coating on a film of fine-grained polyester, etc.
The roughened charging roller of the present invention, which may be fixed, can be used not only in copying machines, but also in electrophotographic applications such as laser printers, LED printers, CRT printers, and photolithography systems.

The present invention will be described below as a specific example of E4-1.

[Example 1] A copying machine NP-3525 manufactured by Canon was modified as shown in FIG. 1 is for NP-3525! light body, 2 is the m main roller that performs direct charging, 3 is image calculation,
4 is the developer, 5 is the transfer paper feed roller and paper feed guy!・
, 6 is a transfer charger, 7 is a separation charger, 8 is a conveyance unit that sends the transfer paper to a fixing device (not shown), 9 is a cleaner, 10 is @
A focused light source, 100, a voltage l1 that applies a voltage to the charging member 2;
It is an il device.

Charging roller No. 2 was manufactured by the following method.

Chlorobu 1/N Rubber [Product Name: Tenka Chlorobu L/N M-
30 made by Denki Kagaku Kogyo Co., Ltd.] 100ffi conductive carbon (product name: Contactex 900 made by Columbian Chemiru Co., Ltd.) is melted and kneaded in the foot part, molded with a stainless steel shaft passed through the center, and then molded with a charging roller. did.

This charging, the average surface roughness (R1) of the roller surface is 0.2
The minimum and maximum surface roughness are 0. Open garden・
0.3 IL was on.

The main roller 11 was first processed at a relative roughening speed of 10100O/F' using the device shown in FIG.
0 seconds, then relative roughening rate 2.0a+a/s io3
When surface roughening was performed using setting 1), the average surface roughness (n) of the surface of this charging roller was 1.
．． 1Jt ■, and the minimum and maximum facetness are each 0.1
It was 1.2μ in the book on 8th. When this charging roller was installed in a copying machine modified by Seishi and subjected to paper passing, no problems occurred until 5,000 sheets were passed. The results of Examples 1 and 1 are shown in Example 1.

The charging exposure conditions are as follows: DC voltage -750 to the charging roller.
V and the AC peak-to-peak type IE1sOOV are set to f]li, and the image exposure amount is k. [Examples 2 and 3] In Example 1, the secondary relative roughness was When the surface of the charging roller was roughened 1) using the same device and a raw charging roller except that the surface was roughened for 25 seconds at a surface roughening speed of LOsm/3, the surface was roughened. The average surface roughness of the roller surface was 1.2 μI, and the minimum and maximum surface roughnesses were 0°9 S and 1.51 J, m, respectively.

In addition, in Example 1, the relative surface roughening rate was 40001/
Then, the surface was roughened for 25 minutes at a relative roughening rate of 1.5 per paper using the same equipment and plain charging roller except for the setting of J. When the roller surface was roughened, the average surface roughness of the roughened charging roller surface was 1.1 mm, and the minimum and maximum surface roughness were 0.8 μm and 1. , 3μ-.

When these two roughened charging rollers were incorporated into an electrophotographic apparatus similar to that of the example and tested for two paper passes, no problems occurred in either case until 51,100 sheets were passed. Among these, 4 Jr.U names, 16 as Example 2, and 16
The results are shown in Table 1, with the name as Example 3.

Comparison C@l) When the same vertical charging roller as in Example 1 was subjected to paper passing durability without roughening it in the same apparatus and under the same conditions as in Example 1, the charging roller and photoreceptor were A horizontal smear image caused by sticking with the drum appeared. This was used as Comparative Example 1 and the results are shown in Table 1.

[Comparative Example 2] In Example 1, the relative roughening rate was 5000 ipm/
The average, maximum, and minimum surface roughness of the charging roller surface was 0.3 μ- or more than 5.0 using the same device and raw charging roller except for C.
If the surface is roughened to fall within the range of p and m, 4'
It took 45 minutes.

Compare this 41 The results are shown in Table 1 as Comparative Example 2.

As shown in Examples 1 to 3 and Comparative Examples 1 and 2,
By roughening the surface of the charging roller by changing the relative roughening speed of the belt-shaped abrasive material to the contact surface of the charging port at the initial stage and after the roughening process, the surface of the charging roller is roughened. Uniform surface roughening can be achieved in a much shorter time than when processing at a relative solidification speed of It is possible to obtain a good image.

Incidentally, the roughened charging roller subjected to the surface roughening treatment of the present invention can be used not only for primary charging but also as a charging member for transfer charging, separation charging, etc.

[Effects of the Invention] When the roughened charging roller of the present invention is used, there will be no sticking or uneven charging between the charging roller and the photoluminescent l-ram, and there will be no scumming due to toner adhesion to the charging roller. We were able to obtain stable repeated images.

4. [Three-sided contact wheel theory [J+] Figure 1 is a structural diagram of a copying machine incorporating a roughening charging roller according to the method of the present invention, and Figure 2 is a diagram of an apparatus implementing the surface roughening method of the present invention. There is an illustrated book.

l...Photoconductor tram 2...Charging roller 3.
... Image fog light 4 ... Developing device 5 ... Transfer paper feed roller and paper feed guide roller ... Transfer charging m
7... Separation charger 8... Conveyance section 9 that feeds the transfer paper to 'i1 charger (not shown)... Cleaner 10.
... Pre-exposure light source 11 ... Charging roller - 12 ... Band-shaped abrasive material 13 ... Feeding roller 14 ... Holding roller 15 ... Winding roller 100 ... Electric S device

Claims (1)

[Claims] (1) In a method of roughening the surface of a charging roller using a band-shaped abrasive material, the relative roughening speed of the abrasive material to the surface in contact with the charging roller is set to a high speed side at the beginning of the roughening process. However, from the next generation onward, the charging roller surface roughening method is characterized by setting the speed to the low speed side.