JPH09114116A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of an interference fringe pattern appearing at the time of image formation and provide a high-quality image. SOLUTION: This electrophotographic photoreceptor 20 is provided with a substrate 201, a drive transmission section 202, and a bearing section 203, and a photosensitive layer is laminated on the outer periphery of the substrate 201. The substrate 201 of the electrophotographic photoreceptor 20 is constituted of a resin, a conductive material, and at least one of a light absorbing material and a light scattering material, and a laser beam transmitting the photosensitive layer and reaching the surface of the substrate 201 is absorbed and/or scattered by the substrate 201. The interference between the laser beam reflected on the surface of the photosensitive layer and the laser beam reflected on the surface of the substrate 201 is remarkably reduced, and the occurrence of an interference fringe pattern appearing at the time of image formation can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning type image recording, for example, an electrophotographic printer, a plain paper fax machine or the like, which records an image by performing optical scanning based on digital image information on a photoconductor. The present invention relates to an electrophotographic photosensitive member provided in an apparatus.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors of this type, for example, photoreceptors provided in electrophotographic printers using a laser as a light source, include selenium, selenium alloys, cured cadmium resin dispersions, or polyvinylcarbazole. Charge transfer complexes such as and trinitrofluorenone have been used. Gas lasers such as helium-cadmium, argon, and helium-neon have been used as lasers, but recently, it is possible to directly modulate the laser light with a driving signal based on digital image information in a small size and at low cost. Various semiconductor lasers have been used. However, most semiconductor lasers have an emission wavelength of 750 nm or more, and the above-mentioned photoconductor has a drawback that the photosensitivity in this emission wavelength region is low. Therefore, it is difficult to use the above-described photoconductor in an image forming apparatus using a semiconductor laser as a light source. Therefore, a multi-layer type photoconductor in which a charge generation layer and a charge transport layer whose light-sensitivity wavelength region can be relatively freely selected are sequentially laminated on a substrate has been attracting attention as a photoconductor for a semiconductor laser printer.

The charge generation layer of the laminated type photoreceptor has a role of absorbing light to generate free charges, that is, photo carriers, and its thickness is 0 in order to shorten the range of the generated photo carriers. It is usually as thin as 1 to 5 μm. This means that most of the incident light amount is absorbed by the charge generation layer to generate a large amount of photo carriers, and further, the photo carriers need to be injected into the charge transport layer without being deactivated by recombination or capture. Is due to. The charge-transporting layer of the multi-layered photoconductor has a role of accepting electrostatic charges and transporting free charges and hardly absorbs image forming light, and its thickness is usually 5 to 30 μm.

When the above-mentioned laminated type photoreceptor is used for a laser printer and the image is formed by line-scanning the laminated type photoreceptor with a laser beam, a line image such as a character is not a problem, but in the case of a solid image, Interference fringe-like density unevenness, that is, moire appeared. And the cause is considered as follows. Since the charge generation layer is formed as a thin layer as described above, the amount of light absorbed by the charge generation layer is limited.
Therefore, the light that has passed through the charge generation layer is reflected on the surface of the substrate, and the reflected light interferes with the light reflected on the surface of the charge transport layer.

For example, as shown in FIG. 6, the multi-layer photosensitive member 41 has a charge generation layer 43 on a metal conductive substrate 42.
The charge transport layer 44 and the charge transport layer 44 are laminated in this order. When laser light 51 (oscillation wavelength is about 780 nm in the case of a semiconductor laser and about 630 nm in the case of a helium-neon laser) is incident on this laminated type photoreceptor 41, the reflected lights 52 and 53 interfere with each other. The reflected light 52 is laser light reflected by the surface of the charge transport layer 44 having high reflection. The reflected light 53 is a laser light that comes out from the surface of the charge transport layer 44 after the intrusion light 54 that has entered the charge transport layer 44 is reflected on the surface of the conductive substrate 42.

Here, the charge generation layer 43 and the charge transport layer 44
Assuming that the refractive index of the laminated layer of and is n, the thickness is d, and the wavelength of the laser light 51 is λ, the intensity of the reflected light 53 is maximum when nd is an integral multiple of λ / 2, that is, the charge transport layer 44 The intensity of light entering the interior is minimal (according to the law of conservation of energy),
When nd is an odd multiple of λ / 4, the intensity of the reflected light 53 is minimum, that is, the intensity of light entering the inside is maximum.

By the way, a thickness unevenness of 0.2 μm or more is unavoidable in the manufacturing process. On the other hand, since the laser light has good monochromaticity and has the same phase, that is, coherent, d
It is considered that the above-mentioned interference condition changes corresponding to the thickness unevenness, and the unevenness of the absorption amount of the laser light in the charge generation layer 43 occurs, which appears as a moire in the solid image. In a normal copying machine, since the light source is not a monochromatic light,
The moiré width changes depending on the wavelength, and it becomes invisible because it is averaged.

Therefore, in order to prevent the occurrence of the above-mentioned moire, Japanese Patent Publication No. 5-26191 discloses that the surface of the substrate should be covered with 0.
A method has been proposed in which minute irregularities of about 1 to 1.0 μm are formed and a photosensitive layer is laminated on this substrate. According to this method, since the laser light is diffused by the unevenness of the substrate, the reflected light 53 that interferes with the reflected light 52 can be reduced, and the occurrence of moire can be prevented.

Further, Japanese Patent Application Laid-Open No. 59-204048 proposes a structure in which an absorption layer for absorbing laser light is laminated between a photosensitive layer and a substrate. According to this configuration,
Since the laser light reflected on the surface of the base body is absorbed by the absorption layer, the reflected light 53 that interferes with the reflected light 52 as described above.
Can be reduced, and the occurrence of moire can be prevented.

Further, the following methods have been proposed as other methods for preventing the occurrence of moire. (1) A method of providing an undercoat layer or an antireflection layer having a light diffusion reflectivity between the substrate and the photosensitive layer. (2) A method in which most of the laser light is absorbed in the charge generation layer. (3) A method in which the binder resin forming the charge transport layer has a microphase-separated structure. (4) A method of providing unevenness on the lower part of the photosensitive layer. (5) Absorb coherent light in the charge generation layer and charge transport layer,
Or a method of mixing a substance that scatters. (6) A method of treating the substrate with colored alumite.

[0011]

However, as disclosed in the above Japanese Patent Publication No. 5-26191, for example, in the method of roughening the surface of the substrate by the sandblast method or the like, moire which appears at the time of image formation. It is difficult to form a rough surface having sufficient and uniform roughness to completely eliminate the above problem. As a result, a relatively large roughness portion generated at a certain ratio acts as a carrier injection portion into the photosensitive layer, resulting in white spots (or black spots when the reversal development method is used) during image formation. The problem of being the cause,
In terms of manufacturing, there is a problem that it is difficult to manufacture a substrate having a uniform rough surface in the same lot.

Further, as disclosed in the above-mentioned Japanese Patent Laid-Open No. 59-204048, the moire can be sufficiently eliminated by the method of providing the light absorbing layer on the substrate or the method of providing the antireflection layer on the substrate. However, there is a problem that the manufacturing cost is increased.

Further, according to the method (1), it is difficult to control the unevenness of the rough surface of the undercoat layer, and therefore it is difficult to obtain the same rough surface with good reproducibility. Therefore, it is difficult to make the quality uniform. Further, in order for the rough surface irregularities of the undercoat layer to be effective against moire, the thickness of the undercoat layer is considerably required. This affects the electrophotographic characteristics such as the sensitivity of the photoconductor and the adhesiveness. Further, the use of such a complicated undercoat layer has a problem of increasing cost.

Methods (2) above include thickening the charge generating layer, bringing the peak of the spectral absorption of the charge generating layer closer to the wavelength of the light source used, and mixing a dye absorbing the light of the light source used. . However, and, respectively, have the following problems. Causes an increase in thermally excited carriers, which has a negative effect on dark decay and the receptive potential. It is difficult to use such a material because it is difficult to obtain such a material, and even if it can be obtained, few materials have sufficient performance. Further, even if the absorption peak and the wavelength of the light source used overlap, there is still a limit to the absorption intensity. However, it is considered that this mixing may affect the electrophotographic properties, and it is difficult to find a dye that has little effect.

In the above method (3), the binder resin to be used must be a block copolymer or a graft copolymer, so that the electrophotographic characteristics can be satisfied and a desired microphase-separated structure can be obtained. Has a problem that is difficult.

The method (4) has been proposed many times, but the unevenness sufficient to prevent the occurrence of moire prevents uniform formation of the photosensitive layer. In particular, since the charge generation layer is generally a thin layer, when the charge generation layer is formed on the unevenness, the thickness of the charge generation layer becomes uneven, which often adversely affects the image characteristics, resulting in cost increase. I have a problem.

In the above method (5), when a substance that absorbs coherent light is added, the sensitivity is lowered, while when a substance that scatters is mixed, image characteristics such as image blurring are deteriorated. I have a problem.

In the above method (6), the substrate can be used only when it is made of metal, and the alumite layer must be thickened in order to prevent the occurrence of moire. As a result, there is a problem that the conductivity of the substrate is deteriorated and the electrophotographic characteristics are adversely affected.

By the way, the photosensitive member is usually made of aluminum or the like formed in a cylindrical shape as a base. However, in order to rotate the photosensitive member in an image forming apparatus such as a printer, a drive transmitting portion or a bearing portion is used. Such a flange is required. The flange is adhered or pressure-bonded to both ends of the base. Therefore, the photoconductor has the following problems. In order to obtain conductivity, the flange is generally manufactured by die-casting a metal such as aluminum or stainless steel and then cutting it with a lathe. Since such processing requires technical skill, the photoreceptor becomes expensive.

When a metal flange is used and the flange itself is processed into a gear shape as a drive connecting means,
Since considerable technical skill is required, it is necessary to provide a separate gear, which increases the number of parts.

A flange in which ABS resin is used instead of metal and which is attached to the drum by a spring made of metal such as copper has also been proposed. However, since the resin molded body and the metal spring are separately formed in this flange, the manufacturing process must be complicated and the conductive performance is not stable. Further, the photoconductor provided with the above flange becomes expensive.

An object of the present invention is to provide an electrophotographic photosensitive member which prevents the occurrence of moire that appears during image formation and can be manufactured at a low cost even if a flange is provided.

[0023]

In order to solve the above-mentioned problems, an electrophotographic photosensitive member according to the invention of claim 1 is provided with a conductive substrate on the surface of which a photosensitive layer is laminated, and is irradiated with laser light to obtain the above-mentioned material. The electrophotographic photosensitive member for exposing the photosensitive layer is characterized in that the conductive substrate contains a substance having at least one of a light absorbing function and a light scattering function.

According to the above structure, the light enters the photosensitive layer,
The laser light that has reached the conductive substrate is absorbed or scattered by the substance, so that the laser light reflected on the surface of the conductive substrate and returning to the outside of the photosensitive layer can be reduced.

As a result, the laser light reflected by the photosensitive layer and the laser light reflected by the surface of the conductive substrate are less likely to interfere with each other, so that the interference fringe pattern appearing at the time of image formation is eliminated, and high image quality is achieved. You can get an image of.

An electrophotographic photosensitive member according to a second aspect of the present invention is the electrophotographic photosensitive member according to the first aspect, characterized in that the conductive substrate is mainly composed of a resin that can be produced by die molding. There is.

According to the above construction, since the resin is the main material, it is easy to mix the substance having at least one of the light absorbing function and the light scattering function. Also,
Since the molding is performed by using a mold, the electrophotographic photosensitive member can be integrally molded, and the surface of the conductive substrate can be easily roughened by roughening the inside of the mold.

As a result, the cost of the electrophotographic photosensitive member can be reduced and the quality can be made uniform.

An electrophotographic photosensitive member according to a third aspect of the present invention is the electrophotographic photosensitive member according to the first or second aspect, wherein the substance having at least one of the light absorbing function and the light scattering function and the conductive substrate are used. It is characterized in that the conductive substance contained in is the same substance.

According to the above structure, since the above-mentioned substance and the conductive substance are the same substance, it is possible to reduce the kinds of substances contained in the conductive substrate and reduce the number of manufacturing steps. .

As a result, the cost of the electrophotographic photosensitive member can be reduced.

The effect described in claim 1 is particularly exerted on the function-separated electrophotographic photoconductor in which the above-mentioned interference fringe pattern is likely to occur.

If the substance having the light absorbing function is a dye having the light absorbing function, the cost of the electrophotographic photosensitive member can be reduced. Further, if the substance having the light absorbing function is conductive carbon, the conductive substance and the substance having the light absorbing function are the same substance, so that further cost reduction can be achieved. it can.

Since the amount of resin used for molding the electrophotographic photosensitive member is proportional to the square of the diameter of the conductive substrate, the inner diameter of the cavity of the mold for molding the conductive substrate should be 40 mm or less. As a result, the amount of resin can be significantly reduced. As a result, the cost of the electrophotographic photosensitive member can be reduced.

Since the resin is used as the main component and the resin is molded by the mold, the conductive substrate, the driving portion, and the both end surface bearing portions can be integrally molded.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 4, a laser printer 37 including the electrophotographic photosensitive member 20 of the present invention includes an electrophotographic photosensitive member 20, a semiconductor laser 21, a rotary polygon mirror 22, an imaging lens 24, a mirror 25, and a corona charger 2.
6, developing device 27, transfer paper cassette 28, paper feed roller 2
9, registration roller 30, transfer charger 31, separation charger 32, conveyor belt 33, fixing device 34, paper discharge tray 35,
And a cleaner 36.

The electrophotographic photosensitive member 20 forms an electrostatic latent image on the surface thereof, and is rotated in the direction of the arrow in the figure by a driving means (not shown). The semiconductor laser 21 emits a laser beam 23. Rotating polygon mirror 22
Is the laser beam 2 on the surface of the electrophotographic photoconductor 20.
3 for repeatedly sweeping in the longitudinal direction (main direction). The imaging lens 24 has the f-θ characteristic,
The laser beam 23 is focused on the electrophotographic photoreceptor 20. The mirror 25 bends the optical path of the laser beam 23. The corona charger 26 is provided on the upstream side of the exposed portion of the electrophotographic photosensitive member 20 to which the laser beam 23 is irradiated, and uniformly charges the surface of the electrophotographic photosensitive member 20.

The developing device 27 is provided on the downstream side with respect to the exposing section and supplies toner to the electrophotographic photosensitive member 20.
The electrostatic latent image is developed as a toner image. The transfer paper cassette 28 is arranged below the developing device 27 and stores the transfer paper. The paper feed roller 29 feeds the transfer paper one by one from the transfer paper cassette 28.
The registration roller 30 feeds the transfer paper to the transfer charger 31 in synchronism with the exposure of the electrophotographic photoreceptor 20. The transfer charger 31 is provided so as to face the electrophotographic photoreceptor 20, and transfers a toner image onto a transfer sheet. The separation charger 32 is adjacent to the transfer charger 31 and removes the charge from the transfer paper to separate it from the electrophotographic photoreceptor 20. The conveyor belt 33 is arranged downstream of the separation charging device 32 and conveys the transfer paper to the fixing device 34. The fixing device 34 fixes the toner image on the transfer paper. The paper discharge tray 35 is for storing the transfer paper on which the image is formed. The cleaner 36 is located upstream of the corona charger 26 and cleans the residual toner on the electrophotographic photoreceptor 20.

As shown in FIG. 1, the electrophotographic photosensitive member 20 includes a base body 201, a drive transmission portion 202, and a bearing portion 2.
03. The base body 201 has a photosensitive layer laminated on the outer peripheral surface thereof, and the base body 20 is a main cause of moire.
The light that reaches 1 is effectively absorbed or diffused by itself. The drive transmission unit 202 transmits the driving force of a drive unit (not shown) to the base body 201.
This drive transmission unit 202 uses a spur gear in the present embodiment, but any drive gear can be used as long as it transmits a driving force to the base body 201. For example, a helical gear, a coupling, an inner gear, or the like may be used. Good. The bearing 203 is the base 2
01 is pivotally supported. Although the bearing portion 203 has a convex shape in the present embodiment, it may have a shape that supports the base body 201, for example, a concave shape. The drive transmission portion 202 is provided at one end of the base body 201, and the bearing portion 203 is provided at the other end.

The electrophotographic photoreceptor 20 is composed of a resin, a conductive substance, and at least one of a light absorbing substance and a light scattering substance. By heating these substances to the melting temperature of the resin or higher and kneading, the conductive substance and at least one particle of the light absorbing substance and the light scattering substance are uniformly dispersed in the resin.

Examples of the above-mentioned resin include resins such as polyacetal resin, polypropylene, polyethylene, polyvinyl chloride, polystyrene, ABS resin, noryl, nylon, polycarbonate, polybutylene terephthalate, and polyethylene fluoride, and mixtures thereof. The material is not limited to these as long as it is a moldable substance.

Examples of the conductive substance include carbon black such as thermal black, acetylene black, furnace black, channel black, lamp black, graphite and graphite, as well as tin oxide, antimony oxide, gold, silver, copper and aluminum. Examples thereof include metals and their compounds such as zinc oxide, titanium dioxide, aluminum oxide, calcium carbonate, barium sulfate, mica, potassium titanate, aluminum borate, and silicon carbide.

Examples of the light absorbing substance include dyes such as phthalocyanine in addition to the various carbon blacks described above, but are not limited thereto. Examples of the light-scattering substance include various metal powders.

The conductive substance and at least one of the light absorbing substance and the light scattering substance may be the same or different. However, by using the same substance,
Since the number of kinds of substances constituting the electrophotographic photosensitive member 20 is small, the manufacturing cost of the electrophotographic photosensitive member 20 can be reduced. For example, various carbon blacks are good conductive substances and also good light absorbing substances, have good dispersibility in resins, and are inexpensive. In addition, various metal powders are both a good light-scattering substance and a conductive substance.

In addition to the above resin, a conductive substance, and at least one substance of a light absorbing substance and a light scattering substance, as fillers, for example, glass beads, titanium oxide, barium sulfate, calcium carbonate, silica, Inorganic pigments such as talc, zinc oxide and clay, or organic pigments may be added. And it is preferable that each substance is 5 to 300 parts by weight with respect to 100 parts by weight of the resin.

Next, a method of molding the electrophotographic photosensitive member 20 will be described below. As the above-mentioned molding method, (1) a method of separately molding the base body 201, the drive transmission portion 202, and the bearing portion 203, and then assembling them, and (2)
There is a method of integrally molding the base body 201, the drive transmission portion 202, and the bearing portion 203. Examples of the method (1) include a method of integrally molding the base body 201 and the drive transmission portion 202 and then assembling the bearing portion 203, and a method of molding the columnar base body 201 by extrusion molding. However, in the case of extrusion molding, after the photosensitive layer is formed on the surface of the base body 201, the drive transmission section 202 and the bearing section 203 are formed.
Since it is necessary to assemble by pressure bonding or adhesion, the manufacturing process increases.

On the other hand, as the method (2), there is a method of using a mold 204 as shown in FIG. The mold 204 is
It consists of mold parts 205 and 206. The mold part 205 is for molding the base 201 and the bearing part 203 of the electrophotographic photosensitive member 20, and has an injection port 207 and an air hole 208 in the upper part. In the mold part 205, the surface in contact with the outer peripheral surface of the base body 201, that is, the surface 205a is roughened by a method such as sandblasting. The degree of roughening is set so that the average surface roughness of the outer peripheral surface of the molded substrate 201 is 1 μm or less. If the average surface roughness is set to 1 μm or more, unevenness in the layer thickness will occur when the charge generation layer 209 is formed, which will be described later. Further, the diameter of the hollow portion 205b of the mold portion 205 is set so that the outer shape of the base body 201 is 40 mm or less. With this numerical setting, (1) a small amount of resin is required for molding, (2) the device can be downsized, (3) the curvature of the electrophotographic photosensitive member 20 becomes large when mounted on a printer or the like. Therefore, since the transfer paper that is in close contact with the electrophotographic photosensitive member 20 is largely bent, the synergistic effect of the stiffness of the transfer sheet and its own weight improves the separability of the transfer paper, and has a basis for each point. ing. The mold 206 is for molding the drive transmission unit 202.

A mold 20 including the mold parts 205 and 206.
In 4, the resin, the conductive substance, and at least one of the light-absorbing substance and the light-scattering substance are melted and kneaded from the injection port 207 of the mold portion 205. Then, after cooling, the mold parts 205 and 206 are removed to obtain the electrophotographic photoreceptor 20 in which the base body 201 having the roughened outer peripheral surface, the drive transmission part 202, and the bearing part 203 are integrally molded.

Next, the substrate 20 of the electrophotographic photoreceptor 20.
A photosensitive layer is formed on the outer peripheral surface of 1. For forming the photosensitive layer, known methods such as a dip coating method, a spray coating method and a slide hopper method are used. The photosensitive layer includes an organic photoreceptor in addition to a sensitized inorganic photoreceptor such as zinc oxide and cadmium sulfide.

An undercoat layer may be provided between the substrate 201 and the photosensitive layer in order to improve the adhesion between the substrate 201 and the photosensitive layer. The material of this undercoat layer is casein,
In addition to nylon resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, urethane resin, polyester resin, phenol resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, polyvinyl formal resin, polyvinyl petitral Polymers such as resins, polyvinyl alcohol resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, vinylidene chloride-acrylonitrile copolymers, styrene-butadiene copolymers,
Examples thereof include celluloses such as ethyl cellulose and carboxymethyl cellulose, which can be used alone or in combination of two or more kinds. The undercoat layer is
The above materials are dissolved in an appropriate solvent and applied on the outer peripheral surface of the base 201 to form a predetermined film thickness. As the coating method, since the substrate 201 has a cylindrical shape without a hollow portion, a dip coating method, a spray method, an extrusion method, a slide hopper method, or the like is preferable. The thickness of the undercoat layer is 0.01 to 10
The range of μm is preferable, and the range of 0.05 to 5 μm is particularly preferable.

In this embodiment, as shown in FIG. 3, the charge generation layer 209 and the charge transport layer 2 are used as the photosensitive layers.
A function-separated organic photosensitive layer composed of 10 is formed on the outer peripheral surface of the substrate 201. The charge generation layer 209 is formed by dispersing a charge generation material in a binder resin, and a known charge generation material is used. For example, azo dyes such as chlorodian blue, quinone pigments such as anthanthrone and pyrenequinone, quinocyanine pigments, perylene pigments, perinone pigments, indigo pigments, phthalocyanine pigments such as pisbenzimidazole pigments, copper phthalocyanine, vanadyl phthalocyanine, azurenium salts, and squares. Lithium pigments, quinacridone pigments and the like can be used.

As the binder resin for the charge generation layer 209, known materials such as polystyrene resin, polyvinyl acetal resin, acrylic resin, methacrylic resin, vinyl acetate resin, polyester resin, polyarylate resin, polycarbonate resin, and phenol resin are used. It

The charge generating layer 209 is formed by containing the charge generating material in the solution of the binder resin and applying it to the outer peripheral surface of the substrate 201. As the solvent used for dispersion, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, etc. are usually used. Any organic solvent can be used. The charge generation layer 209
Generally has a thickness of 0.1 to 5 μm, preferably 0.2 to
2.0 μm is suitable.

The charge transport layer 210 is formed by dispersing a charge transport material in a binder resin, and examples of the charge transport material include polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene, or indole. Compounds having a nitrogen-containing heterocycle such as carbazole and imidazole,
Pyrazoline compounds, hydrazone compounds, triphenylmethane compounds, triphenylamine compounds, enamine compounds, stilbene compounds and the like can be used.

The binder resin for the charge transport layer 210 may be any resin as long as it has a film-forming property. For example, polyester, polysulfone, polycarbonate, polymethylmethacrylate, etc. are used.

For the charge transport layer 210, the charge generation layer 209 is prepared by dissolving the binder resin in a solvent and adding the charge transport material to the solution to obtain a solution having a thickness of 5 to 30 μm.
It is formed by applying on top. As the solvent, aromatic hydrocarbons such as benzene, toluene and xylene, ketones such as acetone and 2-butanone, halogenated hydrocarbon tetrahydrofuran such as methylene chloride, monochlorobenzene and chloroform, and ethyl ether are usually used. Organic solvents can be used.

The charge generation layer 2 on the outer peripheral surface of the substrate 201.
The dip coating method shown in FIG. 5 is used as the coating method for the 09 and the charge transport layer 210. In the dip coating method, uniform coating is possible by appropriately setting the coating conditions such as the viscosity of the coating liquid and the pulling rate according to the shape of the object to be coated.

In FIG. 3A, the electrophotographic photosensitive member 20 is
Is immersed in a coating liquid 211 for coating the charge generation layer 209 or the charge transport layer 210. Then, the same figure (b)
As shown in FIG.
Pull up from 11 at an appropriate speed.

On the other hand, when the object to be coated is cylindrical and one end is open and the other end is closed, the air inside the object is trapped while the object is being pulled up. Up to. However, in such a state, due to a slight temperature difference between the coating liquid and the outside air temperature, the air expands, the solvent of the coating liquid evaporates inside the object to be coated, and the volume increases. Air bubbles are often generated from the lower side of the article to be coated. When such bubbles are generated, the coating liquid is largely shaken, and uneven coating occurs on the coated surface of the object to be coated,
This may hinder the formation of a uniform coating film.

However, since the base 201 of the electrophotographic photosensitive member 20 of the present invention has a cylindrical shape with no hollow portion,
It has no space inside. Therefore, even if the above-mentioned dip coating method is used, bubbles are not generated from the substrate 201, and therefore, the charge generation layer 209 and the charge transport layer 210.
Can have a uniform film thickness.

Next, the image forming operation of the laser beam printer 37 having the electrophotographic photosensitive member 20 will be described below with reference to FIG. The semiconductor laser 21 is driven by a recorded information signal from a document reading device or a computer, and emits a modulated laser beam 23. The laser beam 23 is swept by the rotating multi-area 22 and f-
An image is formed on the electrophotographic photosensitive member 20 rotating in the arrow direction by the image forming lens 34 having the θ characteristic. The optical path of the laser beam 23 is bent by the mirror 25 toward the electrophotographic photosensitive member 20. The surface of the electrophotographic photosensitive member 20 is uniformly charged by the corona charger 26, and then subjected to scanning exposure by the laser beam 23 in a direction substantially parallel to the rotation axis of the electrophotographic photosensitive member 20 to form an electrostatic latent image. To do. Further, the electrophotographic photosensitive member 20 is supplied with toner from the developing device 27. As a result, the toner image is transferred to the electrophotographic photoreceptor 2
0 is formed on the surface. This toner image is transferred onto the transfer paper by the transfer charger 31. The transfer paper is fed from the transfer paper cassette 28 by the paper feed roller 29 and the registration roller pair 30. Then, the transfer paper is separated from the electrophotographic photoreceptor 20 by the separation charger 32. Further, the transfer sheet is conveyed to the fixing device 34 by the conveying belt 33. Then, after the toner image is fixed on the transfer paper by the fixing device 34, the transfer paper is ejected to the paper ejection tray 35. On the other hand, the electrophotographic photoreceptor 20
Continues to rotate during this time and reaches the cleaner 36. Then, the residual toner on the electrophotographic photoconductor 20 is removed by the cleaner 3
The cleaning is performed by 6, and the image formation by the electrophotographic photoconductor 20 is repeated.

Further, as described above, the electrophotographic photoreceptor 20 is used.
When the outer diameter of the base body 201 is 40 mm or less, the separation charger 32 becomes unnecessary. Further, the electrophotographic photoreceptor 20 is
The developing device 27, the corona charger 26, or the cleaner 36 may be incorporated in a process cartridge integrally formed with at least one of the units forming the process around the electrophotographic photoreceptor 20.

For example, as a combination, an electrophotographic photosensitive member, a corona charger, a developing device, and a cleaner are all incorporated, an electrophotographic photosensitive member, a developing device, a corona charger, and an electrophotographic photosensitive member. There are a body and a cleaner incorporated therein, or an electrophotographic photoreceptor and a developing device incorporated therein. The use of the above process cartridge has an advantage that the user's time and effort for exchanging the printer can be omitted. As the charger, any charger such as a corotron, a scorotron, a saw-tooth charger, a roller charger, etc. may be used in addition to the corona charger 26. The developing device may be a two-component or one-component developing device of either a contact type or a non-contact type. Examples of the cleaner include a blade cleaner and a brush cleaner.

As described above, the substrate 201 of the electrophotographic photosensitive member 20 is composed of the resin, the conductive substance, and at least one of the light absorbing substance and the light scattering substance, and has a surface. Since the surface is roughened, it is possible to effectively absorb or diffuse the laser light reaching the surface of the base body 201, which is the main cause of moiré, by itself. Therefore, as described above, in an image forming apparatus including an electrophotographic photosensitive member having a function-separated organic photosensitive layer that easily causes moire, particularly a function-separated photosensitive layer having a transparent layer formed on the substrate surface, A high quality image can be obtained.

The electrophotographic photosensitive member 20 has a base 201.
Since the drive transmission unit 202 and the bearing unit 203 are molded by the mold 204 using resin as a main material, it is easy to mix at least one of the light absorbing substance and the light scattering substance, and the conductivity is improved. It is also possible for the substance and the substance mentioned above to be identical. In addition, the base body 201, the drive transmission portion 202, and the bearing portion 203 are integrally molded, and the surface of the base body 201 can be easily roughened. Therefore, the cost of the product can be reduced.

Furthermore, since the substrate 201 has a substantially columnar shape with no hollow portion, the layer thickness is constant even when the photosensitive layer is formed by the dip coating method.

[0067]

As described above, the electrophotographic photosensitive member according to the invention of claim 1 is provided with a conductive substrate having a photosensitive layer laminated on the surface thereof, and the electrophotographic photosensitive member is irradiated with laser light to expose the photosensitive layer. In the body, the conductive substrate contains a substance having at least one of a light absorbing function and a light scattering function.

As a result, the interference between the laser light reflected by the photosensitive layer and the laser light reflected by the surface of the conductive substrate is less likely to occur, so that the interference fringe pattern that appears during image formation is eliminated, and high image quality is achieved. The effect of being able to obtain the image of is obtained.

An electrophotographic photosensitive member according to a second aspect of the present invention is the electrophotographic photosensitive member according to the first aspect, wherein the conductive substrate is mainly composed of a resin that can be produced by die molding.

As a result, the cost of the electrophotographic photosensitive member can be reduced and the quality can be made uniform.

An electrophotographic photosensitive member according to a third aspect of the present invention is the electrophotographic photosensitive member according to the first or second aspect, wherein the substance having at least one of the light absorbing function and the light scattering function and the conductive substrate are used. It is characterized in that the conductive substance contained in is the same substance.

As a result, the cost of the electrophotographic photosensitive member can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of an electrophotographic photosensitive member of the present invention.

2 is a cross-sectional view showing a schematic configuration of a mold for integrally molding the electrophotographic photosensitive member shown in FIG.

FIG. 3 is a cross-sectional view showing a schematic configuration of an electrophotographic photosensitive member on which a photosensitive layer is formed.

FIG. 4 is a schematic diagram showing a schematic configuration of a laser printer including the electrophotographic photosensitive member shown in FIG.

5A and 5B are explanatory views schematically showing a dip coating method that is generally used for forming a photosensitive layer on an electrophotographic photosensitive member.

FIG. 6 is an explanatory diagram showing how laser light is reflected and refracted in a layer structure of a conventional electrophotographic photosensitive member.

[Explanation of symbols]

 20 Electrophotographic Photoreceptor 201 Substrate (Conductive Substrate) 209 Charge Generation Layer (Photosensitive Layer) 210 Charge Transport Layer (Photosensitive Layer)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouji Imae 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (3)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive substrate having a photosensitive layer laminated on the surface thereof and exposing the photosensitive layer by irradiating a laser beam, wherein the conductive substrate has a light absorbing function and a light scattering function. An electrophotographic photoreceptor containing a substance having at least one of the functions described above. 2. The electrophotographic photosensitive member according to claim 1, wherein the electroconductive substrate is mainly made of a resin that can be produced by die molding. 3. The substance having at least one of the light absorbing function and the light scattering function and the conductive substance contained in the conductive substrate are the same substance. The electrophotographic photosensitive member according to 1.