JPH09292730A - Electrophotographic photoreceptor for reversal development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent interference fringes and black spots by a simple structure and to obtain a high quality image by specifying the interval of peaks and the max. height of the surface toughness of the anodically oxidized layer and specifying the surface gloss. SOLUTION: The surface of an aluminum supporting body is anodically oxidized, and the surface of the anodically oxidized layer has 0.3 to 250μm peak interval, preferably 30 to 100μm, and 0.5 to 2.5μm max. height, preferably 0.7 to 1.8μm. The surface gloss of the anodically oxidized surface is controlled to >=60 gloss, preferably >=80 gloss. If the peak interval is <0.3μm, interference fringes can not be suppressed enough. If the interval exceeds 250μm, irregularity as stripes is caused. If the max. height is <0.5μm, interference fringes can not suppressed enough, and if it exceeds 2.5μm, irregularity as stripes is caused. If the gloss is <60 gloss, an enough effect to suppress black spots for a white copy image can not be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor having an anodized layer and used in a reversal development system.

[0002]

2. Description of the Related Art Although electrophotographic technology has been developed in the field of copying machines, recently, conventional apparatuses have rapidly spread due to incomparable high image quality, high speed, and quietness. Laser beam printers, digital copiers, etc., have received particular attention due to the remarkable progress of the data processing system. As an image forming method used in these devices, a so-called reversal developing method is adopted in which toner is attached to a portion irradiated with light to form an image for the purpose of effectively utilizing light or increasing resolution. As a result, it has come to be required that the photosensitive member has high reliability during reversal development.

As a photoconductor used in such an electrophotographic apparatus, a photoconductor having a structure in which a photosensitive layer is directly formed on a conductive support is generally used. However, in such a photoconductor, when laser light is used as the light source, there is a problem that interference fringes are caused by interference of light reflected on the photoconductor surface and the support surface. In order to eliminate this, a method of dispersing a light-scattering pigment in the undercoat layer, a method of increasing the absorption of the charge generation layer to absorb and attenuate reflected light, a component which roughens the surface of the support and specularly reflects it. A method for suppressing the above is known. Among them, the method of appropriately roughening the surface of the support is widely used because interference fringes can be prevented regardless of the constitution of the photosensitive layer. As the technique for roughening the surface, for example, Japanese Patent Laid-Open Nos. 58-35544 and 60-101545 disclose precision lathe cutting, Japanese Patent Laid-Open Nos. 53-134244 and 56-150754. Japanese Patent Laid-Open Publication No. 1993-242242 discloses grinding by using a grindstone.

[0004]

However, in order to completely prevent the interference fringes only by the roughening treatment by the method described in the above publication, it is necessary to delicately control the cutting pitch or the grinding conditions. High technology is required, and the manufacturing cost is increased.

On the other hand, in general, in a photoreceptor having a structure in which a photosensitive layer is directly formed on a conductive support, the blocking action for preventing charge injection from the conductive support to the photosensitive layer is insufficient, At the time of reversal development, a toner image is formed in a place where a toner image should not be formed, which causes so-called black spot image noise.

Therefore, it is an object of the present invention to prevent both interference fringes and black spots generated during reversal development using a laser beam as a light source with a novel and simple structure as much as possible.

[0007]

According to the present invention, an anodic oxide layer and a photosensitive layer are formed on a conductive support made of aluminum or an aluminum alloy, and the ridge spacing Sm on the surface of the anodic oxide layer.
Is 0.3 to 250 μm and the maximum height Rt is 0.5 to 2.
5 μm, and the surface glossiness on the anodized layer surface is 6
The technology relates to an electrophotographic photosensitive member for reversal development, which is characterized in that it is 0 gloss or more.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION That is, in the present invention, an anodic oxide layer is provided on a conductive support made of aluminum or an aluminum alloy (hereinafter referred to as an aluminum support) to have a specific surface roughness, and By setting the glossiness on the surface to a specific value, it is possible to prevent the occurrence of interference fringes more than in the case where the surface of the conductive support is only roughened, and at the same time, between the conductive support and the photosensitive layer. The presence of the anodic oxide layer formed in (1) prevents the injection of charges from the support side to the photosensitive layer side as much as possible and suppresses the generation of black spots.

The support of the electrophotographic photosensitive member of the present invention is a substrate made of aluminum or an aluminum alloy with its surface roughened. The roughening method may be any conventionally known method, for example, cutting with a cutting tool, grinding with a grindstone, sandblasting, wet honing, etc., but from the viewpoint of cost merit and simplification of the process, Most preferable is the cutting treatment by. The surface roughness of the aluminum support is not particularly limited, and is appropriately adjusted so that the surface roughness and glossiness after forming the anodized layer described later fall within predetermined ranges.

Further, as the material of the aluminum support, in the case of pure aluminum or an aluminum alloy, the total content of Si, Fe and Mn should be 0.5 wt% or less, preferably 0.2 wt% or less. Is preferred. The reason for this is that these metals are likely to form crystallization products by the anodizing treatment described later, the irregularities on the surface of the anodizing layer become large, and it is difficult to obtain the desired roughness and glossiness.

Next, the surface of the aluminum support is subjected to anodizing treatment, sealing treatment, etc., so that the surface of the anodizing layer is JI.
The mountain interval Sm in S B 0601-1982 is 0.
3 to 250 μm, preferably 30 to 100 μm, and the maximum height Rt is 0.5 to 2.5 μm, preferably 0.7 to
It is 1.8 μm, and the surface glossiness on the surface of the anodized layer is 60 gloss or more, preferably 80 gloss or more. If Sm is less than 0.3 μm, interference fringes cannot be sufficiently suppressed, while if it exceeds 250 μm, streaky unevenness occurs. If Rt is less than 0.5 μm, interference fringes cannot be sufficiently suppressed, and if it exceeds 2.5 μm, streaky unevenness occurs. Further, when the glossiness is less than 60 gloss, a sufficient effect cannot be obtained for suppressing black spot noise during white copying.

The thickness of the anodized layer is 1 to 15 μm,
The thickness is preferably 2 to 10 μm, more preferably 4 to 8 μm.

The glossiness correlates with the roughness of the surface of the anodized layer, and the roughness and glossiness of the surface of the anodized layer should be determined by appropriately selecting the material, roughness and anodizing condition of the aluminum support. Can be adjusted to a desired range. For example, regarding the material of the aluminum support, S
The smaller the content of i, Fe, Mn, etc., the smaller the Rt of the anodized layer and the greater the degree of gloss.
Regarding the roughness of the support, the glossiness of the anodized layer tends to increase as Sm increases and Rt decreases.
Further, the glossiness can be increased by performing anodizing treatment for a long time at a low current density. Furthermore, the glossiness can be adjusted by the etching conditions such as acid and alkali that are used as a pretreatment for the anodizing treatment. Specifically, the glossiness can be increased by a long-time etching treatment with a low solution concentration. Is. Furthermore, the glossiness can also be adjusted by a sealing treatment.

The glossiness of the present invention is JIS K 54.
It is the value measured based on 00 according to the 60-degree specular gloss test.

The anodizing treatment is generally carried out by chromic acid, sulfuric acid,
It is carried out in an acidic bath of oxalic acid, boric acid, sulfamic acid, etc., but in the present invention, anodizing treatment in sulfuric acid is the best. Sulfuric acid concentration is 100 to 300 g / l, dissolved aluminum concentration is 2 to 15 g / l, liquid temperature is 15 to 30
C. and the electrolysis voltage are preferably set in the range of 5 to 20V. Further, in the present invention, the above-mentioned support surface is treated with a current density of 0.3 to 1.0 A / dm ² , preferably 0.6 to 1.0 A / dm ² , and more preferably 0.7 to 1.0 A / dm ² .
It is preferable to carry out anodizing treatment at a low current density of about 0.8 A / dm ² for a relatively long time of about 25 to 60 minutes.

The obtained anodic oxide coating has a porous portion, and since it is unstable, a sealing treatment is performed. Examples of the sealing treatment include a low temperature sealing treatment of immersing in an aqueous solution containing nickel fluoride as a main component, a high temperature sealing treatment of immersing in an aqueous solution containing nickel acetate as a main component, and the like.

In the case of high-temperature sealing treatment, a metal salt aqueous solution of nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, barium acetate or the like can be used as the sealing agent, and nickel acetate is most preferable. .

When an aqueous solution of nickel acetate is used, the concentration is preferably 3 to 20 g / l, and the pH is preferably 5.0 to 6.0. The treatment temperature is 65 to 100 ° C, preferably 80 to 98 ° C.

The concentration of the nickel fluoride aqueous solution used in the low temperature sealing treatment can be appropriately selected, but it is 3 to 6 g / l, p.
It is preferable to use H in the range of 5.5 to 6.0.
The treatment temperature is 25 to 35 ° C., preferably 30 to 35
° C.

As described above, an anodized layer having a predetermined roughness and glossiness in the photoconductor of the present invention can be obtained.

A photosensitive layer is formed on the anodized layer formed as described above. The photosensitive layer may be any of a form in which a charge generation layer and a charge transport layer are sequentially stacked, a form in which a charge transport layer and a charge generation layer are sequentially stacked, and a single layer type form including a charge transport material and a charge generation material. May be.

A mode in which a charge generation layer and a charge transport layer are sequentially laminated as a photosensitive layer will be described below.

The charge generating layer is formed by vacuum depositing the charge generating material, or by dissolving the charge generating material in a solvent such as amine and applying it, or by dissolving the pigment in a suitable solvent or a solution in which a binder resin is dissolved if necessary. The charge-generating layer is formed by coating and drying the coating liquid prepared by dispersing. On this, a solution containing a charge transport material and a binder resin is applied and dried to form a charge transport layer.

Examples of the charge generating material used in the photoreceptor of the present invention include bisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, cyanine dyes, styryl dyes, pyrylium dyes. Examples include organic substances such as dyes, azo dyes, quiacdrine dyes, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indathlon pigments, squarylium pigments, and phthalocyanine pigments. In addition, any material that absorbs light and generates charge carriers with extremely high efficiency can be used.

The charge transporting material used in the photoreceptor of the present invention is preferably an organic substance such as a hydrazone compound, a pyrazoline compound, a styryl compound, a triphenylmethane compound, an oxadiazole compound, a carbazole compound, a stilbene compound, Various materials such as enamine compounds, oxazole compounds, triphenylamine compounds, tetraphenylbenzidine compounds and azine compounds can be mentioned.

The binder resin used in the production of the above-mentioned photoreceptor is electrically insulating, and is measured by itself to be 1 × 10 ¹²
It is desirable to have a volume resistance of Ω · cm or more. For example, a binder such as a thermoplastic resin, a thermosetting resin, a photocurable resin, or a photoconductive resin known per se can be used. Specifically, polyester resin, polyamide resin, acrylic resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-
Thermoplastic resins such as butadiene block copolymer, polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide, styrene resin; epoxy resin, urethane resin, silicone resin, phenol resin, melamine resin, xylene resin, alkyd resin , Thermosetting resins such as thermosetting acrylic resins; photocurable resins; photoconductive resins such as polyvinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylpyrrole, etc., and these binder resins may be used alone or in combination of two or more. Used in combination.

When the charge transport material is a polymer charge transport material which itself can be used as a binder, other binder resin may not be used.

The photoreceptor of the present invention includes a binder resin, a plasticizer such as halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutylphthalate, and O-terphenyl, chloranil, tetracyanoethylene, 2,4,7.
-Trinitrofluorenone, 5,6-dicyanobenzoquinone, tetracyanoquinodimethane, tetrachlorophthalic anhydride, electron-withdrawing sensitizer such as 3,5-dinitrobenzoic acid, methyl violet, rhodamine B, cyanine dye, pyrylium salt A sensitizer such as thiapyrylium salt may be used.

The photoreceptor of the present invention may have a structure in which an intermediate layer is provided on the anodized layer. Suitable materials for the intermediate layer are nylon resin, polyimide resin, polyamide resin, nitrocellulose polyvinyl butyral resin, polyvinyl alcohol resin, and the like. The film thickness is 0.1
30 μm, preferably 1 to 30 μm, more preferably 1
˜20 μm.

Further, the photoreceptor of the present invention may be provided with a surface protective layer. As a material used for the surface protective layer, a polymer such as an acrylic resin, a polyarylate resin, a polycarbonate resin or a urethane resin as it is, or a material in which a low resistance compound such as tin oxide or indium oxide is dispersed is suitable. An organic plasma polymerized film can be used as the protective layer. The organic plasma polymerized film may optionally contain oxygen, nitrogen, halogen, and atoms of groups 3 and 5 of the periodic table.

The process to which the photoconductor of the present invention is applied is not particularly limited, but in the image forming process in which an image is formed through the steps of charging, exposing, developing and transferring, charging to development is performed. Time to reach 300 ms
It is preferably used in the image forming process of ec or higher. The black spot noise at the time of reversal development tends to become worse as the time from charging to development becomes longer, but in the electrophotographic photoreceptor for reversal development of the present invention, disadvantageous image formation with respect to the generation of black spots. It can be used well under process conditions.

[0032]

【Example】

Example 1 JIS 6063 cylindrical aluminum alloy (outer diameter 80 m
m, length 350 mm, thickness 1.0 mm) The surface was cut with a cutting tool using natural diamond as a cutting blade. This was degreased with a degreasing agent (surfactant) at 60 ± 5 ° C. for 5 minutes and washed with running water. Then, after performing an etching treatment with 100 g / l nitric acid for 2 minutes, it was washed with running pure water.

Next, 150 g / l sulfuric acid was used as an electrolytic solution, and anodizing treatment was performed at a current density of 1 A / dm ^{2 at} a solution temperature of 20 ° C. for 25 minutes to form an anodized layer having a thickness of 7 μm. This was washed with running pure water, and then a pore-sealing treatment was performed at 85 ° C. for 20 minutes using a 5 to 10 g / l nickel acetate aqueous solution, followed by washing with pure water and drying. 1 part by weight of τ type metal-free phthalocyanine and polyvinyl butyral resin (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.) on the above anodized layer.
5 parts by weight and 50 parts by weight of tetrahydrofuran (THF) were dispersed by a sand mill. The resulting phthalocyanine-based dispersion was applied so that the film thickness after drying would be 0.3 μm to form a charge generation layer.

The following formula:

[0035]

Embedded image

10 parts by weight of the benzyldiphenyl compound represented by the formula and a polycarbonate resin (Panlite K-1
300 parts, manufactured by Teijin Kasei Co., Ltd.) and 10 parts by weight of dichloromethane in 180 parts by weight are applied to the above charge generation layer to form a charge transport layer having a thickness of 24 μm and dried. An electrophotographic photoconductor was produced.

Example 2 Other than that in Example 1, the etching time was 3 minutes, the current density was 0.7 A / dm ² for 35 minutes anodizing, and the sealing temperature was 90 ° C. In the same manner as in Example 1, an electrophotographic photosensitive member for reversal development of the present invention was produced.

Example 3 In Example 1, JIS 500 was used as the conductive support.
An electrophotographic photosensitive member for reversal development of the present invention was prepared in the same manner as in Example 1 except that 5 aluminum alloy was used and the surface of the conductive support was cut by changing the feed rate and cutting depth of the cutting tool. did.

Example 4 Using JIS 1100 aluminum alloy as a conductive support, the same cutting process and anodic oxide layer formation as in Example 1 were performed.

Copolymerized nylon (CM80
00, manufactured by Toray Industries, Inc.) 4 parts by weight dissolved in 56 parts by weight of methyl alcohol was applied to form an intermediate layer having a film thickness of 0.5 μm.

Further, 4.5 parts by weight of α-type titanyl phthalocyanine and 4.5 parts by weight of polyvinyl butyral (BH-3, manufactured by Sekisui Chemical Co., Ltd.) were dispersed in a sand mill together with 500 parts by weight of dichloroethane. The liquid was applied so that the film thickness after drying would be 0.2 μm to form a charge generation layer. Then the following formula:

[0042]

Embedded image

40 parts by weight of a distyryl compound represented by and a polycarbonate resin (PC-Z: manufactured by Mitsubishi Gas Chemical Co., Inc.)
A solution of 60 parts by weight and 500 parts by weight of tetrahydrofuran was applied and dried to form a charge transport layer having a film thickness of 30 μm, and the electrophotographic photoreceptor for reversal development of the present invention was produced.

Example 5 In Example 4, JIS 6063 having the aluminum alloy component shown in Table 1 was used as the conductive support, and the surface of the conductive support was cut by changing the feed rate and cutting amount of the cutting tool. An electrophotographic photosensitive member for reversal development of the present invention was produced in the same manner as in Example 1 except that it was processed.

Example 6 In Example 1, the conductive support has an outer diameter of 100 m.
m, length 350 mm, thickness 2.0 mm cylindrical JIS
An electrophotographic photosensitive member for reversal development of the present invention was produced in the same manner as in Example 1 except that 5657 material was used and the surface of the conductive support was cut by changing the feed rate and cutting depth of the cutting tool. did.

Comparative Example 1 The electrophotographic photosensitive member for reversal development of the present invention was carried out in the same manner as in Example 1 except that JIS 6063 having an aluminum alloy component shown in Table 1 was used as the conductive support. Was produced.

Comparative Examples 2 to 4 In the same manner as in Example 1 except that the surface of the conductive support was cut by changing the feed rate and cutting depth of the cutting tool in Example 1, the reversal development electron of the present invention was used. A photographic photoreceptor was produced.

Comparative Examples 5 to 6 JIS 3003 or JIS 5005 having the alloy components shown in Table 1 as the conductive support in Example 1.
Was used, and the electrophotographic photosensitive member for reversal development of the present invention was produced in the same manner as in Example 1 except that the surface of the conductive support was cut by changing the feed rate and cutting depth of the cutting tool.

Comparative Example 7 In the same manner as in Example 1 except that the surface of the conductive support was cut by changing the feed rate and the depth of cut of the cutting tool in Example 1 and no anodic oxide layer was provided. An electrophotographic photoreceptor for reversal development of the present invention was produced.

With respect to the photoconductors prepared in Examples 1 to 6 and Comparative Examples 1 to 7, the peak spacing Sm and the maximum peak height Rt were measured as the roughness on the surface of the anodized layer, and the results are shown in Table 1. . The roughness is a value measured with a surface roughness meter (Surfcom, manufactured by Tokyo Seimitsu Co., Ltd.) at a cutoff value of 0.8 mm.

Further, in the above photoreceptor, the glossiness on the surface of the anodized layer was measured using (Glossmeter GM060, manufactured by Minolta Co., Ltd.). The results are shown in Table 1.

Further, the amounts of Si, Fe and Mn as impurities contained in the anodized layer are the values analyzed by emission spectroscopy, and the results are shown in Table 1.

Evaluation The photoconductors obtained in Examples 1 to 5 and Comparative Examples 1 to 7 were mounted on a commercial full-color copying machine (CF80, manufactured by Minolta Co., Ltd.), and interference fringes and black spots were observed at a system speed of 218 mm / sec. Image evaluation was performed. The results are shown in Table 1. The wavelength of the laser light from the light source is 0.78μ
m, and the maximum light amount was 12.5 erg / cm ² .
The photoreceptor of Example 6 was evaluated using the electrophotographic copying machine described below.

FIG. 1 is a sectional view showing the schematic arrangement of a color electrophotographic copying machine 1 used for image evaluation in Example 6. FIG.
As shown in FIG. 1, the copying machine 1 is roughly divided into an image reader unit 2 for reading image data of a document and a printer unit 3 for printing an image on a transfer material.

The image reader unit 2 has a document table 21 on which a document is placed, an exposure lamp 22 and a mirror 23,
Scanner 24 moved in the direction of arrow c (sub-scanning direction)
A CCD sensor 25 for converting the reflected light from the document surface into an electric signal and outputting it; a mirror 26 and a condenser lens 27 for guiding the reflected light from the document surface to the CCD sensor 25;
The signal processing unit 28 converts the output from the D sensor 25 into a laser drive signal.

The printer section 3 has a photosensitive drum 5 which is an image bearing member at a substantially central portion thereof, and the photosensitive drum 5 is further provided.
A transfer drum 6 facing each other, a fixing device 7 located above the transfer drum 6, a laser optical system 8 located above the photoconductor drum 5, and a paper feed cassette 9 located below the photoconductor drum 5. I have it.

The transfer drum 6 is provided around the photosensitive drum 5.
From the top to the bottom in order of the rotation direction of the photosensitive drum 5 indicated by an arrow a in the figure, the blade type cleaner 1 as a cleaning means.
0, a charger 11 for charging the photosensitive drum 5, and a developing device 1 for each color of yellow, magenta, cyan, and black for developing the photosensitive drum 5 on which an electrostatic latent image is formed.
2Y, 12M, 12C and 12Bk are provided.

The transfer drum 6 is provided rotatably in the direction of the arrow b in the figure, and is provided with a cylindrical transfer film 13 to which a transfer material such as the paper S is adsorbed. Transfer film 1
A transfer charger 15 for transferring a toner image from the photoconductor drum 5 to the paper S is provided inside the sheet 3 at a position facing the photoconductor drum 5, and the toner is sequentially transferred along the transfer drum 6 in the direction of the arrow b. Electrostatic fur brush roller 1 for cleaning the surface of transfer film 13 and separation charger 17 and separation claw 18 for separating the paper S on which the image is transferred
9, a static eliminator charger 20 for neutralizing the transfer film 13,
The paper pressing roller 14 that presses the paper S against the transfer film 13 at the paper feed position of the paper S, the paper S with the transfer film 13
An adsorption charger 15 is provided for adsorbing to the.

The laser optical system 8 emits a laser diode based on the image signal output from the image reader unit 2, a collimating lens for guiding the emitted laser beam to the photosensitive drum 5 and irradiating the laser beam, a polygon mirror, and Fθ. It has a lens and a reflection mirror.

A plurality of paper cassettes 9 are provided, and each paper feed cassette 9 contains a plurality of paper sheets. Based on the copy start instruction, the sheets are separated one by one from the selected sheet feeding cassette 9 and fed toward the transfer drum 6.

Next, a description will be given of the copying operation of the color electrophotographic copying machine 1 having the above structure.

When an original is placed on the original table 21 and a copy switch (not shown) is pressed, the image reader unit 2
The document placed on the document table 21 is illuminated by the exposure lamp 22, and the reflected light from the document surface is focused on the CCD sensor 25 via the mirrors 23 and 26 and the condenser lens 27. In this state, the scanner 24 is moved in the direction of arrow c by the drive motor to scan the entire document surface. CCD sensor 25
Sequentially converts the reflected light from the document surface into an electric signal and outputs the electric signal to the signal processing unit 28.

On the other hand, in the printer section 3, the paper feed cassette 9
Then, a suitable sheet S is conveyed to the transfer drum 6 by the sheet feeding / conveying roller 39. Paper S conveyed to transfer drum 6
Is attracted onto the transfer film 13 by an electrostatic attraction charger 15 provided so as to face the paper pressing roller 14.

Then, based on the yellow laser driving signal output from the image reader unit 2, the photosensitive drum 5 charged by the charging charger 12 is irradiated with laser light to form an electrostatic latent image, and the yellow image is formed. The image is visualized with toner by the developing machine 12Y and transferred onto the sheet S adsorbed on the transfer film 13. Photoconductor drum 5 on which the toner image is transferred
The residual toner is cleaned by the cleaner 10. Then, the photoconductor drum 5 is charged again by the charging charger 11, and subsequently, an electrostatic latent image is formed on the photoconductor drum 5 based on the magenta laser drive signal to form the magenta developing device 12.
Paper S on which the yellow image has been transferred and visualized by M
Transcribed above. Thereafter, in the same manner, cyan and black toner images are transferred to the paper S one after another.

The sheet S on which the yellow, magenta, cyan, and black toners have been transferred in an overlapping manner is separated from the transfer film 13 by the separation charger 17 and the separation claw 18 and sent to the fixing device 7. In the fixing device 7, the toner transferred by the heating and pressing action is fixed on the sheet S.

The sheet S on which the toner image is fixed is separated from the transfer film 13 and conveyed to the fixing device 7, where the toner image is fixed on the sheet S, and the sheet S is discharged to the discharge tray 4.

(Interference fringes) The occurrence of interference fringes in a halftone image (using black toner) at an image density of 0.5 (Sakura densitometer, manufactured by Konica Corporation) was visually evaluated in the following three grades.

◯: No interference fringes were generated Δ: Interference fringes were partially generated, but there was no problem in practical use ×: Interference fringes were generated on the entire surface and was unusable (black spots) Black Copy a solid white image using toner and copy 2
The number of black spots existing in 5 mm ² was visually inspected and evaluated according to the following three grades.

○: less than 15 △: 15 or more and less than 30 ×: 30 or more

[0070]

[Table 1]

[0071]

As described above in detail, in the electrophotographic photoreceptor for reversal development of the present invention, the surface of the aluminum support is subjected to anodizing treatment so that the degree of roughening and the glossiness fall within specific ranges. By providing the layers, both the interference fringes and the black spots were improved and a very high quality image could be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a full-color electrophotographic copying machine to which a photoconductor of the present invention can be applied.

[Brief description of reference numerals]

 1 Electrophotographic Copier 5 Photoreceptor Drum 8 Laser Optical System Xa @ Paper Feed Cassette 11 Charging Charger 12Y Yellow Developer 12M Magenta Developer 12C Cyan Developer 12Bk Black Developer

Claims (1)

[Claims] 1. An anodized layer and a photosensitive layer are formed on a conductive support made of aluminum or an aluminum alloy, and a mountain interval Sm on the surface of the anodized layer is 0.3 to 250 μm.
An electrophotographic photosensitive member for reversal development, which has a maximum height Rt of 0.5 to 2.5 μm and a surface glossiness of 60 gloss or more on the surface of the anodized layer.