JP2876059B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly, to interference fringes (moire fringes) due to multiple reflections in a photoreceptor even when a semiconductor laser is used as a light source. The present invention relates to an electrophotographic photoreceptor capable of suppressing the occurrence of ()).

[Problems to be solved by conventional technology and invention]

In general, an electrophotographic photoreceptor comprises a support (9) and a photosensitive layer (10) comprising a conductive layer (8), a charge transport layer (6) and a photoconductor layer (7) as shown in FIG. Are laminated, and the surface of the support (9) is composed of a substantially smooth surface, and accordingly, the photosensitive layer (10) is also composed of a smooth surface.

When light is incident on such a photoreceptor from the outside, the light causes multiple reflections inside the photosensitive layer (10) as shown in FIG. In FIG. 3, n ₂ , n ₁ , and n ₀ are the refractive indexes of air, the photosensitive layer, and the conductive layer, respectively, and d ₁ is the thickness of the photosensitive layer. For the sake of simplicity, if the coherent light enters the photosensitive layer vertically from above, the reflectance r _{0 on the} surface of the conductive layer and the reflectance r _{1 on the} surface of the photosensitive layer are respectively calculated from the Fresnel equation. Is represented by In addition, the reflectance R ₁ of light incident on the photosensitive layer is
The superposition of I, II and III is expressed by the following equation.

However, δ ₁ = 4πn ₁ d ₁ / λ Since n ₂ <n ₁ <n ₀ (the conductive layer is a metal deposition film),
When δ ₁ = 2kπ (k = 0,1,2,3 ...), Δ ₁ = (2k + 1) π (k = 0,
1,2,3…) And the reflectance becomes minimum.

Transmittance T and reflectance R is because in R + T = 1 the relationship, the intensity of light absorbed in the photosensitive layer for each film thickness of the photosensitive layer is lambda / 4n ₁ change indicates a change in the maximum minimum, the photosensitive layer And light and dark interference fringes in accordance with the film thickness distribution are obtained. A charge pattern is formed on the photosensitive layer according to the distribution of light intensity absorbed by the photosensitive layer, and interference fringes are also seen on the image. Since the photosensitive layer material is mainly made of a polymer material,
Since n ₁ is about 1.8 and the wavelength λ is about 800 nm in the case of the most common GaAs semiconductor laser, λ / 4n ₁ ≒ 0.1
2 μm.

Accordingly, the photosensitive member shown in FIG. 2 has a photosensitive layer thickness of 0.12 μm.
Each time the light intensity changes, the local maximum of light intensity is changed by interference, and as a result, interference fringes of equal thickness (often appearing like a grain) appear on the image. It is practically difficult to make the thickness variation of the photosensitive layer 0.12 μm or less.

As a method of preventing the occurrence of interference fringes as described above,
A method has been proposed in which the surface of the support is polished with a liquid abrasive or sandblasted to roughen the surface (see, for example, JP-A-57-165844). Since materials and processing agents are used, after the processing, an abrasive or the like remains on the surface of the support, and an image was formed by an electrophotographic process using an electrophotographic photosensitive member including the support. In this case, there is a disadvantage that a clear image cannot be obtained. Further, it has been difficult to make the surface properties uniform with such a processing method.

Further, when a support as shown in FIG. 2 is used, the flatness of the back surface of the support is too good, so that there are the following problems.

Generally, when an electrophotographic photoconductor having an endless belt shape is used in an electrophotographic process, the photoconductor belt is driven using two or more rolls. FIG. 4 (a) shows the case of driving by two rolls, and FIG. 4 (b) shows the case of driving by three rolls. In these figures, 20 is an endless photoreceptor belt, 21 is a conductive layer, 22a, 22b, 22c
Is a roll. When the endless photoreceptor belt (20) is used in an electrophotographic process in such a driving method, a problem is the shift of the belt (20). This belt (2
The deviation of 0) changes the speed, direction, and displacement of the belt due to insufficient accuracy such as deviation of the circumference of the belt, run-out of the rolls, and parallelism. Has a mechanism to prevent exercise. FIGS. 4 (c) and 4 (d) show an example of the deviation prevention mechanism. The belt (20), which has moved in either direction by driving, comes into contact with the end face of the rolls (22a, 22b, 22c) and the slip prevention guide (23) installed at the widthwise end of the back of the belt. No more leaning exercises will be performed. When the endless photoreceptor belt (20) is driven by the driving method shown in FIG. 4, one roll is usually made of a material such as rubber for driving, and the other is made of a material having a low friction coefficient such as aluminum. And a roll that follows the movement of the belt. The belt shift movement is a movement in which the magnitude of the shift force largely depends on the friction coefficient between the belt back surface and the roll.

In such a belt driving system, it is required that the magnitude of the belt deviation is small, the force applied to the belt deviation prevention mechanism is small, and the belt does not slip in the driving direction. That is, it is desirable that the friction coefficient between the back surface of the belt and the drive roll has a sufficient coefficient of friction, and the friction coefficient between the other driven roll and the back surface of the belt is as small as possible.

In a conventional photoreceptor belt as shown in FIG.
The coefficient of friction is large because the belt back is flat. In the drive system as shown in FIG. 4 (c), a sufficient drive force can be obtained, but at the same time, the shift force increases, and the durability of the shift prevention mechanism is often shortened.

In the present invention, in an electrophotographic photosensitive member having an endless belt shape made of a polymer film, it is possible to eliminate the interference effect of light due to multiple reflection of light in the photosensitive member, and to prevent the occurrence of interference fringes to achieve a sharp image. In addition to providing an image, it is an object of the present invention to provide an endless belt photoreceptor for electrophotography which can reduce the magnitude of belt deviation in a belt drive system and improve the durability of a belt deviation prevention mechanism. Aim.

[Means and Actions for Solving the Problems]

According to the present invention, in an electrophotographic photoreceptor in which a conductive layer, a photoconductor layer and a charge transport layer are sequentially provided on an endless belt-shaped support using a polymer film, an inorganic pigment is used as a support for the resin. Dispersed materials are used, and continuous fine protrusions are provided on the upper and lower surfaces of the support, and the average surface roughness R (a) and the maximum surface roughness R (max) are within the following ranges. An electrophotographic photoconductor is provided.

λ / 4n ₁ ≦ R (a) ≦ 0.5 μm 1.5 μm ≦ R (max) ≦ 5 μm (where λ is the wavelength of the light source used in the electrophotographic process,
n ₁ is the refractive index of the photosensitive layer of the photosensitive member. The electrophotographic photoreceptor of the present invention basically has a structure as shown in FIG. 1, and is formed by evaporating Al formed along fine projections on the surface of the support (4). The surface of the conductive layer (3) is an irregular reflection surface for preventing regular reflection of incident light, and the photoconductor layer (2) and the charge transport layer (1) are sequentially laminated on the conductive layer (3). Have been. Support (4)
Is a surface having the same fine projections as the upper surface.

Since the electrophotographic photoreceptor of the present invention has the above-described configuration, when coherent light enters from outside, light transmitted through the charge transport layer (1) and the photoconductor layer (2) is transmitted to the conductive layer (3).
The light will be irregularly reflected on the surface. Due to this reflection, light having various optical path differences interferes within a very localized range, and as a result, the manifested interference effect is not recognized.

Therefore, in the electrophotographic photoreceptor of the present invention, since the interference effect due to multiple reflection of light inside the photoreceptor does not appear, the grain pattern does not appear on the image. Therefore, a high quality image can be provided. Also,
In the present invention, since the synthetic resin in which the inorganic pigment particles are dispersed is used as the support, fine protrusions on the upper and lower surfaces of the support are formed of the inorganic pigment particles coated with the resin, and therefore, the abrasive material, etc. This does not cause an image defect unlike a support having finer irregularities.

Further, in the present invention, by setting the surface property of the lower surface of the support as described above, the friction coefficient of the rear surface of the endless photoreceptor belt is reduced, and the deviation preventing mechanism of the belt drive system as shown in FIG. Improves durability. The coefficient of friction between the drive roller and the driven roller is large enough to drive the endless belt, and it is sufficient to set the coefficient of friction between the driven roller and the driven roller as small as possible. The friction coefficient is also in a good range, and the magnitude of the deviation force is very small as compared with a support having good flatness as shown in FIG. 2 while obtaining a sufficient driving force. Hereinafter, the present invention will be described in more detail.

In the present invention, a synthetic resin in which an inorganic pigment is dispersed is used as the support (4) of the polymer film. As the synthetic resin, for example, a polyester resin, a phenol resin, a synthetic resin commonly used in this field such as a polypropylene resin is used, and as the inorganic pigment, silica, talc, alumina or the like is preferably used. .

Further, in the present invention, continuous fine projections are provided on the upper and lower surfaces of the support, and the average surface roughness R (a) and the maximum surface roughness R (max) are adjusted to be in the following ranges.

_{λ / 4n 1 ≦ R (a} ) ≦ 0.5μm 1.5μm ≦ R (max) ≦ 5μm average surface roughness R (a) and the maximum surface roughness R (max) is the photosensitive member inside to be outside the range The desired effect of the present invention cannot be achieved because the effect of suppressing multiple reflection is insufficient.

The projections provided on the upper and lower surfaces of the support have one or more peaks indicating projections of 1.5 μm or more and 5 μm or less in a scanning section of 1 mm, and five or more peaks indicating projections of 0.5 μm or more and less than 1.5 μm. It is desirable to have it exist.

The conductive layer (3) is formed on the upper surface of the support by a method such as vacuum deposition, sputtering, and suction coating.
It is formed by coating an electrically conductive substance such as stainless steel, carbon, SnO ₂ , and In ₂ O ₃ .

On the surface of the conductive layer (3), fine projections are provided similarly to the surface of the support, and the average surface roughness R (a) and the maximum surface roughness R (max) are λ / 4n ₁ ≦ It is preferable to adjust R (a) ≦ 0.5 μm 1.5 μm ≦ R (max) ≦ 5 μm from the viewpoint of the effect.

As for the protrusions provided on the surface of the conductive layer (3), one or more peaks indicating protrusions of 1.5 μm or more and 5 μm or less exist in a 1 mm scanning section, and peaks indicating protrusions of 0.5 μm or more and less than 1.5 μm are present. It is desirable to have five or more.

The photosensitive layer (5) comprises a photoconductor layer (2) and a charge transport layer (1).
, And those conventionally known can be applied as they are.
Hereinafter, the photoconductor layer (2) and the charge transport layer (1) will be described.

(Photoconductor layer)

The photoconductor layer is a layer intended to generate and separate electric charges by image exposure. The charge generating substance is an organic dye or pigment, crystalline selenium or arsenic selenide, and the organic pigment is a phthalocyanine pigment, disazo pigment, trisazo pigment, perylene pigment, squaric salt dye, azurenium salt dye, quinone System-condensed polycyclic compounds and the like. Organic dyes and pigments are used in a resin or without a resin and by adding an organic solvent to be dispersed by a method such as ball milling, ultrasonic wave, three-roll, sand glider, attritor, impeller, and stone mill. As a resin for dispersing these organic dyes, for example, polyamide, polyurethane, polyester, epoxy resin, polycarbonate, polycondensation resin such as polyether and polystyrene, polyacrylate, polymethacrylate,
Polymers and copolymers such as poly-N-vinyl carbazole, polyvinyl butyral, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, and the like are required, and insulation and adhesiveness are required. The photoconductor layer is formed on the conductive layer and dried to form a layer having a thickness of 0.05 to 0.5 μm. The content of the organic dye / pigment is preferably from 60 to 100% by weight. The crystalline selenium particles and arsenic selenide alloy particles are:
The particles are used by dispersing them in an electron donating binder by the same method as described in the description of the intermediate layer such as a ball mill. The crystalline selenium particles used here are:
A known method, for example, high-purity selenium can be heated and dissolved in a high-concentration strong alkaline aqueous solution, and the solution can be dropped into pure water or neutralized with an acid to precipitate as crystalline selenium (hexagonal). On the other hand, arsenic selenide particles, for example, 0.01 To
It can be obtained by heating and evaporating arsenic selenide in nitrogen or an inert gas at rr to 1 Torr.

Examples of the electron-donating organic compound for dispersing the crystalline selenium particles and arsenic selenide particles used in the present invention as the photoconductor layer include polyvinyl carbazole and derivatives thereof (for example, halogen such as chlorine or bromine in the carbazole skeleton, Having a substituent such as a methyl group or an amino group), nitrogen-containing compounds such as polyvinylpyrene, oxadiazole, pyrazoline, hydrazone, diarylmethane, α-phenylstilbene, and triphenylamine-based compounds, and diarylmethane-based compounds. However, polyvinyl carbazole and its derivatives are particularly preferred.
Further, these compounds may be used as a mixture. Also in the case of mixing and using, it is preferable to add another electron donating organic compound to polyvinyl carbazole and its derivative.
Preferred reasons include that polyvinyl carbazole and its derivatives have a higher ionization potential than other electron donating organic compounds, and that the charge transport layer can be easily formed by coating because it is a polymer itself. . Charge generation material content is 30% by weight of the whole layer
It should be up to 90% by weight. In the present invention, an intermediate layer may be provided, and a photoconductor layer having a thickness of 0.2 μm to 5 μm may be formed on the same intermediate layer as the intermediate layer by drying and drying.

(Charge transport layer)

The charge transport layer provided on the photoconductor layer retains charged charges on its surface, and moves and separates the charges generated and separated in the photoconductor layer by exposure to combine with the charged charges held. It is a layer aimed at. High electrical resistance is required to achieve the purpose of retaining the charged electric charge, and in order to achieve the purpose of obtaining a high surface potential with the retained charged electric charge, a low dielectric constant and good charge mobility are required. Required. To satisfy these requirements,
An organic charge transfer layer containing an organic charge transfer material as an active ingredient is used. Examples of the organic charge transfer material include poly-N-carbazole compounds, pyrazoline compounds, α-phenylstilbene compounds, hydrazone compounds, diarylmethane compounds, triphenylamine compounds, divinylbenzene compounds, and fluorene compounds. Conventionally known compounds such as compounds, anthracene compounds, oxadiazole compounds, and diaminocarbazole compounds can be used. These organic charge transfer materials other than polymers such as polyvinyl carbazole,
As a binder, it is used by being blended with a resin similar to that shown in the photoconductor layer such as polycarbonate. However, the resin used in the photoconductor layer and the resin used in the charge transport layer need not be the same. In addition, a plasticizer is added to these as needed. Examples of such a plasticizer include polymers and copolymers of halogenated paraffin, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, and the like, and polyester. The charge transfer material, the binder resin, and silicone oil (as a leveling agent at the time of film formation) are dissolved in an organic solvent, and the film is formed and dried in the same manner as the photoconductor layer. A 100 μm charge transport layer is formed on the photoconductor layer. The ratio of the charge transfer material to the resin binder is 2/8 to 8/2 by weight, and the amount of silicone oil to the resin binder is 0.001% to 1% by weight.

〔Example〕

Example 1 Silica particles having an average particle size of 1.45 μm were used as polyester resin.
From a mixture of 0.3% by weight and dispersed, an Al vapor-deposited film having a thickness of 600 mm was formed on a base film which was biaxially stretched to a thickness of 75 μm and formed. The surface roughness of the Al-deposited surface was measured using a stylus-type surface roughness meter (550AD type, manufactured by Tokyo Seimitsu Co., Ltd.) according to JISB-0601 (the same applies hereinafter).
(A) = 0.25-0.30 μm, maximum surface roughness R (max) = 2.7
μm. Similarly, when the surface roughness of the back surface of the base film was measured, the average surface roughness R (a) was 0.25 to 0.30 μm.
m, and the maximum surface roughness R (max) was 2.7 μm. Also Al
The surface gloss of the deposited surface was measured using a gloss meter (VGS-1D, Nippon Denshoku Industries Co., Ltd.) according to JISZ8741 (the same applies hereinafter) and found to be 300 Gs (60 °). A photoconductor layer and a charge transport layer were sequentially laminated and coated on the conductive layer composed of the Al vapor-deposited film to obtain an electrophotographic photosensitive member. This photoreceptor was processed into an endless belt shape, embedded in a laser printer (manufactured by Ricoh Co., Ltd., LP4081), and an electrophotographic image was formed. No interference effect due to multiple reflections in the photoreceptor was observed on the image. No interference fringes were generated. Further, in this image, image defects such as white spots and black spots were not recognized in up to 2,500 prints. The magnitude of the biasing force of the endless photoreceptor belt is measured by measuring the amount of contraction of a spring using a biasing force measuring roller (see FIG. 5).
When calculated based on the relational expression of the amount of spring shrinkage × spring coefficient k (the same applies hereinafter), the biasing force is about 200 gf and 50,000
No damage to the belt shift prevention mechanism was observed in up to two prints.

Comparative Example 1 A base obtained by subjecting Al particles to vapor deposition in the same manner as in Example 1 was prepared by mixing and dispersing 0.05% by weight of silica particles having an average particle diameter of 1.45 μm in a polyester resin. When the surface roughness of the Al-deposited surface was measured, the average surface roughness R (a)
= 0.10 to 0.15 µm, and the maximum surface roughness R (max) = 1.0 µm. The surface glossiness of the Al-deposited surface was 600 Gs (60 °). A photoreceptor obtained by applying a photosensitive layer to this base film in the same manner as in Example 1 was processed into an endless belt shape, incorporated into the same laser printer, and formed an image. The occurrence of interference fringes due to the interference effect was observed on this image. Image defects such as white spots and black spots were not observed in this image.

Comparative Example 2 A 75 μm-thick polyester film was prepared in the same manner as in Example 1.
A base on which Al deposition was performed was created. When the surface roughness of the Al-deposited surface was measured, the average surface roughness R (a) = 0.05 to
0.10 μm and maximum surface roughness R (max) = 1.0 μm.
The surface glossiness of the Al-deposited surface was 800 Gs (60 °).
When the surface roughness of the back surface of the polyester film was measured, the average surface roughness R (a) was 0.05 to 0.10 μm, and the maximum surface roughness R (max) was 1.0 μm. A photosensitive layer was applied on the conductive layer in the same manner as in Example 1, and processed into an endless belt shape. When an electrophotographic image was formed by the same laser printer, generation of interference fringes was recognized. Further, the magnitude of the deviation force of the endless belt was about 600 gf, and damage was recognized in a part of the belt deviation prevention mechanism in up to 50,000 prints.

Example 2 Silica particles having an average particle size of 1.45 μm were used as polyester resin.
An Al vapor-deposited film having a thickness of 600 mm was formed on a base film which was mixed and dispersed at 0.1% by weight, biaxially stretched to a thickness of 75 μm and formed.
When the surface roughness of the Al-deposited surface was measured, the average surface roughness R (a) = 0.20 to 0.25 μm, and the maximum surface roughness R (max)
= 2.0 μm. In addition, this surface has one or more peaks indicating protrusions of 1.5 μm or more and 5 μm or less in a scanning section of 1 mm and 0.5 μm
As described above, there were five or more peaks indicating protrusions smaller than 1.5 μm. The surface roughness of the back surface of the base film is as follows: average surface roughness R (a) = 0.20 to 0.25 μm, maximum surface roughness R (ma
x) = 2.0 μm. The surface glossiness of the Al-deposited surface is 40
It was 0 Gs (60 ゜). A photoconductor layer and a charge transport layer were sequentially applied to the Al-deposited surface of the base film to form an electrophotographic photosensitive member. When this photoreceptor was processed into an endless belt shape and incorporated into the same laser printer to form an image, no interference fringes were observed on the image due to the interference effect, and no image defects were observed in up to 25,000 prints. Did not. The magnitude of the deviation of the endless photoreceptor belt was about 150 gf, and no damage was observed in the belt deviation prevention mechanism in up to 50,000 prints.

Example 3 Silica particles having an average particle size of 1.5 μm were used as polyester resin.
A 1.0% by weight mixture was dispersed and then biaxially stretched to a thickness of 75 μm and formed into a base film to form an Al vapor-deposited film having a thickness of 600 mm. The surface roughness of the Al-deposited surface was measured with a stylus-type surface roughness meter, and the average surface roughness R (a) was 0.30 to 0.40.
μm, and the maximum surface roughness R (max) = 4.5 μm. The surface roughness of the back surface is an average surface roughness R (a) = 0.30 to 0.40 μm,
The maximum surface roughness R (max) was 4.5 μm. When the surface glossiness of the Al-deposited surface was measured, it was 100 Gs (60 °). On this conductive layer, a photoconductor layer and a charge transport layer were sequentially laminated and applied to obtain an electrophotographic photosensitive member. This photoreceptor is processed into an endless belt shape, built into the same laser printer,
When an electrophotographic image was formed, no occurrence of interference fringes due to the interference effect was observed on the image, and no image defect was observed in up to 25,000 prints. No image defects such as black dots and white dots were observed in this image.

Comparative Example 3 A glass bead (average particle diameter: 105 μm) was sprayed on a 75 μm-thick polyester film by an air pressure of 1 kg / cm ² to perform sandblasting. 60 on this surface
An Al vapor-deposited film having a thickness of 0 mm was formed, and a photoconductor layer and a charge transport layer were sequentially formed by coating to obtain an electrophotographic photosensitive member. When this photoreceptor was incorporated in the same laser printer to form an image, no interference fringes were observed on the image, but black spots were observed. Also, a residual abrasive was observed on the photoreceptor corresponding to the black spot image.

Comparative Example 4 A 75 μm polyester film was subjected to a liquid homing process. Alumina having an average particle size of 105 μm was used as the abrasive. An Al vapor-deposited film having a thickness of 600 mm was formed on the treated surface, and a photoconductor layer and a charge transport layer were sequentially formed by coating to obtain an electrophotographic photosensitive member. When this photoreceptor was incorporated in the same laser printer and formed an image, no interference fringes were observed on the image, but black spots were observed. Also, a residual abrasive was observed on the photoreceptor corresponding to the black spot image.

〔The invention's effect〕

Since the electrophotographic photoreceptor of the present invention has the above-described configuration, even if coherent light such as a semiconductor laser beam is used as a light source, it is possible to eliminate light interference due to multiple reflections in the photoreceptor. Therefore, occurrence of interference fringes is suppressed, and a high-quality image can be provided.

In addition, it is possible to reduce the magnitude of the belt deviation force in the belt drive system and improve the durability of the belt deviation prevention mechanism.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electrophotographic photosensitive member according to the present invention, FIG. 2 is a schematic sectional view of a conventional electrophotographic photosensitive member, and FIG. 3 is a diagram illustrating multiple reflection inside the photosensitive member. FIG. 4 is an explanatory view of a belt drive system, and FIG. 5 is an explanatory view of a biasing force measuring roller. DESCRIPTION OF SYMBOLS 1 ... Charge transport layer 2 ... Photoconductor layer 3 ... Conductive layer 4 ... Support 5 ... Photosensitive layer

Continuation of the front page (56) References JP-A-62-186270 (JP, A) JP-A-60-247647 (JP, A) JP-A-63-192053 (JP, A) JP-A-61-240247 (JP, A) , A) JP-A-63-48560 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5/00-5/16

Claims (4)

(57) [Claims] 1. An electrophotographic photoreceptor comprising a conductive layer, a photoconductor layer and a charge transport layer sequentially provided on an endless belt-shaped support comprising a polymer film, wherein an inorganic pigment is dispersed in a resin as a support. And continuous fine protrusions are provided on the upper and lower surfaces of the support, and that the average surface roughness R (a) and the maximum surface roughness R (max) are within the following ranges. A photoconductor for electrophotography, characterized by: λ / 4n ₁ ≦ R (a) ≦ 0.5 μm 1.5 μm ≦ R (max) ≦ 5 μm (where λ and n ₁ are the wavelength when the electrophotographic photosensitive member is used and the refractive index of the photosensitive layer of the photosensitive member, respectively) is there.) 2. The conductive layer is made of a metal vapor-deposited film, and the surface of the conductive layer has continuous fine projections, and has an average surface roughness R (a) and a maximum surface roughness R (max). 2. The electrophotographic photosensitive member according to claim 1, wherein λ / 4n ₁ ≦ R (a) ≦ 0.5 μm 1.5 μm ≦ R (max) ≦ 5 μm. (3) The upper and lower surfaces of the support have a 1.5 mm scanning interval.
2. The electrophotographic photoreceptor according to claim 1, wherein one or more peaks indicating protrusions of not less than 5 [mu] m and not more than 5 [mu] m exist, and at least five peaks indicating protrusions of not less than 0.5 [mu] m and not more than 1.5 [mu] m exist. 4. The surface of the conductive layer has a thickness of 1.5 μm during a scanning section of 1 mm.
2. The electrophotographic photoreceptor according to claim 1, wherein one or more peaks indicating protrusions of m to 5 [mu] m are present, and five or more peaks indicating protrusions of 0.5 [mu] m to 1.5 [mu] m are present.