JP4132274B2 - Cylindrical electrophotographic photoreceptor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylindrical electrophotographic photosensitive member, and more particularly, to a cylindrical electrophotographic photosensitive member that is small in deformation of a rotational driving gear and excellent in dimensional accuracy and can be stably rotated.
[0002]
[Prior art]
In recent years, electrophotographic technology has been widely used not only in the field of copiers but also in the fields of various printers and facsimiles because it can provide images with immediacy, high quality and high storage stability. .
This electrophotographic process basically includes charging a photosensitive member, forming an electrostatic latent image by image exposure, developing the latent image with toner, and transferring the toner image to paper (in some cases, via a transfer member in the middle). And an image forming process by fixing.
[0003]
A photoreceptor that is the core of electrophotographic technology is used by attaching a flange having a gear for rotation driving to the end of a cylindrical photosensitive drum on which a photosensitive layer such as a charge generation layer and a charge transport layer is formed. .
As shown in FIG. 3, the flange 3 of the electrophotographic photosensitive member is formed with a drum fitting portion 4 to be fitted to the end portion of the photosensitive drum 2 on one end side of the substantially cylindrical body, and rotationally driven on the other end side. A gear 5 for transmitting force is formed.
[0004]
Further, between the drum fitting portion 4 and the gear 5, a hub 6 for preventing deformation of the flange and fitting a rotation shaft (not shown) of the flange 3 is formed. An intermediate wall 7 having a hole in the center is formed on the inner surface.
When the flange 3 is mounted on the photosensitive drum 2, in order to securely fit the flange 3 and the photosensitive drum 2 so that they do not loosen during use and do not run out or come out. Usually, the outer diameter of the drum fitting portion 4 of the flange 3 is made larger than the inner diameter of the photosensitive drum 2, and this is press-fitted with a large force.
[0005]
Therefore, in the conventional flange 3, the drum fitting portion 4 is reduced in diameter as shown by a two-dot chain line in FIG. 4, and the gear 5 is deformed in the direction in which the diameter is increased in order to deform with the intermediate wall 7 as a fulcrum, When the dimensional accuracy of the gear 5 is lowered and rotationally driven, there is a problem that the rotational accuracy is lowered and pitch unevenness is generated on the image.
[0006]
[Problems to be solved by the invention]
The present invention is a cylindrical electrophotographic device that is not deformed, has a flange having a gear portion with excellent dimensional accuracy, is driven smoothly over a long period of time, has high rotational accuracy, and does not cause pitch unevenness on an image. A photoconductor is provided.
[0007]
[Means for Solving the Problems]
The present invention has been made as a result of intensive studies from such a viewpoint. In a cylindrical electrophotographic photosensitive member in which a flange having a rotation driving gear is attached to an end portion of a photosensitive drum, the flange is substantially cylindrical. A drum fitting portion to be fitted to the end portion of the photosensitive drum is formed on one end side, a gear for rotation driving is formed on the other end side, and an intermediate wall is provided only at a position inside the photosensitive drum in the substantially cylindrical body . A cylindrical electrophotographic photosensitive member is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the cylindrical electrophotographic photoreceptor 1 of the present invention has a flange 3 attached to the end of a photosensitive drum 2 having a photosensitive layer formed on the outer surface.
The photosensitive drum 2 is not particularly limited in its constituent materials, but a photosensitive layer is formed on the surface of a cylindrical substrate, and the substrate can be formed into a cylindrical shape with a high dimensional accuracy and a heat-resistant material. .
Specifically, synthetic resins such as glass, ceramics, polyethylene, polypropylene, polycarbonate, and polyamide, and metals such as copper and aluminum can be used. Of these, aluminum is preferable.
When a non-conductor is used, it is common to conduct a conductive material by blending a conductive powder or to conduct a conductive surface by metal vapor deposition.
[0009]
Hereinafter, the manufacturing method will be described in the case of using aluminum as a substrate. After processing aluminum or an aluminum alloy such as A1050, A3003, A6063 into a cylindrical shape by a porthole method, a mandrel method, etc., a predetermined thickness, length, outer In order to obtain a cylindrical cylinder having a diameter, processing such as drawing and cutting is performed.
In general, the processed substrate is usually anodized. As conditions for the anodizing treatment, conventionally known conditions are arbitrarily selected and adopted. Specifically, sulfuric acid, oxalic acid, phosphoric acid, or the like can be used as the electrolytic solution for anodizing treatment. Of these electrolytes, sulfuric acid is preferred. In the case of sulfuric acid alumite treatment, the sulfuric acid concentration in the electrolytic solution is preferably selected from the range of 100 to 300 g / L, and the temperature of the electrolytic solution is selected from the range of 10 to 30 ° C. The energization time is appropriately determined depending on the thickness of the target anodized film. The thickness of the anodic oxide coating is suitably in the range of 2 to 15 μm.
[0010]
The anodized substrate is subjected to sealing treatment. As the sealing treatment solution, a conventional sealing treatment solution such as a solution containing nickel ions (for example, a solution containing nickel acetate or a solution containing nickel fluoride) can be used.
A photosensitive layer is formed on the sealed substrate. The photosensitive layer is a layer in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order, or a laminate in which the charge generation material particles are dispersed in a charge transport medium. Any of a dispersion type and the like can be used, but a laminated photosensitive layer having a charge generation layer and a charge transport layer is preferable.
[0011]
Charge generation materials include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, other inorganic photoconductors, azo pigments such as Sudan Red, Diane Blue, and Dienas Green B, disazo pigments, argol yellow, pyrenequinone And quinocyanine pigments such as quinocyanine pigments, quinocyanine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments such as Indian First Orange toner, phthalocyanine pigments such as copper phthalocyanine, quinacridone pigments, pyrylium salts, and azurenium salts. Of these, oxytitanium phthalocyanine is preferable.
[0012]
Charge transport materials include polyaromatic compounds such as anthracene, pyrene, phenanthrene, coronene or indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline, thiadiazole, triazole in the main chain or side chain Examples thereof include compounds having a skeleton of a nitrogen-containing cyclic compound such as, and hole transport materials such as hydrazone compounds.
[0013]
Examples of the binder resin for forming the photosensitive coating film include polycarbonate, polyarylate, polystyrene, polymethacrylic acid esters, styrene-methyl methacrylate copolymer, polyester, styrene-acrylonitrile copolymer, polysulfone, polyvinyl acetate, poly Examples include acrylonitrile, polyvinyl butyral, polyvinyl pyrrolidone, methyl cellulose, hydroxymethyl cellulose, and cellulose esters.
[0014]
As the coating solvent, a solvent having high volatility and a vapor density larger than that of air is preferably used. For example, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, 4-methoxy-4-methyl-2-pentanone, dimethoxymethane, dimethoxyethane, 2,4-pentadione, anisole, methyl 3-oxobutanoate, monochlorobenzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, Examples thereof include methyl cellosolve, ethyl cellosolve, and methyl cellosolve acetate.
[0015]
The coating solution for the photosensitive material in the case of producing a single layer type electrophotographic photosensitive member is prepared by mixing the charge generating substance, the charge transporting substance, the binder resin and the coating solvent. The photosensitive material coating solution used in the production of the laminated electrophotographic photosensitive member includes a charge generating layer coating solution comprising the charge generating material, a binder resin and a coating solvent, and the charge transporting material. A charge transport layer coating solution comprising a binder resin and a coating solvent is prepared separately.
[0016]
The concentration of each component in the coating solution is appropriately selected according to a known method. The concentration of the solid content is mainly determined according to the film thickness of the layer to be formed. In the case of a coating solution for producing a single-layer type electrophotographic photosensitive member, a laminated type electrophotographic photosensitive member is produced. In the case of the coating liquid for the charge transport layer, the amount is adjusted to 40% by weight or less, preferably 10 to 35% by weight. In the case of these coating solutions, the viscosity is 50 to 300 cps, preferably 70 to 250 cps, and the dry film thickness is 15 to 40 μm.
[0017]
In the case of a coating solution for a charge generation layer, the solid concentration is 15% by weight or less, preferably 1 to 10% by weight, and the dry film thickness is usually 0.1 to 1 μm. .
The above coating is usually performed by dip coating, that is, a method in which the cylindrical substrate is vertically lowered and immersed in the coating solution in a dipping tank in which the coating solution has overflowed, and then the cylindrical substrate is vertically lifted and pulled up. Is called.
The photosensitive drum 2 thus obtained is provided with flanges 3 at both ends thereof. The geared flange 3 of the present invention may be attached to both ends of the photosensitive drum 2, or a flange having no gear may be used at one end and the other end.
[0018]
As shown in FIG. 1, the flange 3 used in the present invention is formed of a substantially cylindrical body. The flange 3 is made of a material having rigidity and excellent dimensional accuracy, and a synthetic resin such as polyamide, polycarbonate, polyphenylene ether, ABS resin, polyacetal or polyphenylene sulfide, or a metal such as copper or aluminum is used.
When a defective conductor such as a synthetic resin is used, it is generally used by making it conductive by blending conductive powder such as metal powder, carbon black, and graphite.
[0019]
Moreover, in order to improve physical properties, the synthetic resin may be used in combination of two or more resins, and may be used in combination with other materials as long as the characteristics are not impaired. In this case, it can be used in combination with a resin containing reinforcing fibers such as glass fibers, carbon fibers, and alumina fibers or bead-like reinforcing materials. The reinforcing fiber and the bead-like reinforcing material may be used alone or in combination of two or more, but the reinforcing fiber mainly composed of glass fiber is advantageous in terms of cost.
[0020]
The flange 3 has a drum fitting portion 4 into which the photosensitive drum 2 is fitted on one end side of a substantially cylindrical body, and a gear 5 on the outer periphery on the other end side. An outwardly projecting ridge 8 is formed at the center side end of the drum fitting portion 4, and its side wall 8a constitutes a stopper that determines the stop position of the drum. An intermediate wall 7 is formed on the inner surface of the substantially cylindrical body, and a hub 6 for inserting a rotating shaft (not shown) of the electrophotographic photosensitive member 1 is formed at the center of the intermediate wall 7. Intermediate wall 7 is formed on the drum engaging portion 4 the inner surface corresponding to the sensitive optical drum 2 internal position. Preferably, it is formed at a position of 0 to 60%, preferably 10 to 50% of the length from the point where the end of the photosensitive drum 2 is located to the tip of the drum fitting portion 4 as a base point.
[0021]
The flange 3 used in the present invention can be made of a material that forms the gear 5 portion and a material that forms the flange fitting portion 4 using different types of synthetic resins.
That is, the gear portion can be formed of a synthetic resin having high slidability and wear resistance. Examples of the synthetic resin suitable for this purpose include polyacetal, ABS resin, polycarbonate, polybutylene terephthalate, polyphenylene oxide, polypropylene, and nylon.
[0022]
A general-purpose synthetic resin or an engineering plastic can be used as the synthetic resin forming the other part. Further, as described above, a reinforcing material or the like can be added.
When molding with different materials, a two-color molding method can be employed.
Further, as shown in FIG. 2, the coupling with the drum 2 can be improved by fitting a sleeve 11 formed of an elastic material around the outer periphery of the drum fitting portion 4.
[0023]
【The invention's effect】
In the present invention, since the intermediate wall is provided only at the position inside the photosensitive drum in the substantially cylindrical body, even when the flange is attached to the photosensitive drum, the deformation stress of the drum fitting portion is not transmitted to the gear portion even when the flange is pressed. Maintain a predetermined dimensional accuracy. Therefore, a practical cylindrical electrophotographic photosensitive member can be obtained in which the electrophotographic photosensitive member can be driven smoothly, can be stably driven for a long period of time, and can prevent color misregistration of an image.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a flange portion showing a cylindrical electrophotographic photosensitive member of the present invention.
FIG. 2 is a longitudinal sectional view showing another example of a flange used in the present invention.
FIG. 3 is a longitudinal sectional view showing a conventional flange.
FIG. 4 is a longitudinal sectional view showing deformation of a conventional flange.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical electrophotographic photosensitive member 2 Photosensitive drum 3 Flange 4 Drum fitting part 5 Gear 7 Intermediate wall 8 Projection 8a Projection sidewall 11 Sleeve

Claims (4)

In a cylindrical electrophotographic photosensitive member in which a synthetic resin flange having a rotation driving gear for rotating the electrophotographic photosensitive member is fitted to the end of the photosensitive drum by press fitting, the flange is exposed to one end side of the substantially cylindrical member. A drum fitting portion to be fitted to the drum end portion is formed, a rotation driving gear is formed on the other end side, and the photosensitive drum is exposed from a position inside the substantially cylindrical body where the end portion of the photosensitive drum is located at the time of mounting. has an overall intermediate wall only on the drum center side, further intermediate wall cylindrical electron, characterized in Tei Rukoto is formed at a position in its entirety it does not include a position on an end portion substantially the same plane of the photosensitive drum Photoconductor. Between the drum engagement part and the gear before Symbol flange, cylindrical electrophotographic photosensitive member according to claim 1, projection projecting outwardly is formed.   The cylindrical electrophotographic photosensitive member according to claim 1, wherein the flange is formed by molding a drum fitting portion and a gear portion with different synthetic resins by two-color molding. 2. A synthetic resin flange having a rotational driving gear for rotating an electrophotographic photosensitive member is attached to one end of the photosensitive drum by press fitting, and a flange having no gear is attached to the other end. 4. The cylindrical electrophotographic photosensitive member according to any one of 3 above.

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