JPH04171455A - Electrophotographic sensitized body, and copying machine and facsimile using the same sensitized body - Google Patents

Abstract

PURPOSE:To enable the coating of a protecting layer on a photosensitive layer without harming the photosensitive layer by containing a polymer or a copolymer, provided with specific unit elements, in an intermediate layer. CONSTITUTION:In an electrophotographic sensitized body provided with a photosensitive layer, an intermediate layer and a protecting layer on a conductive base body in this order from the base body side, the intermediate layer contains a polymer or a copolymer having unit elements expressed in a formula I. In the formula I, R<1> is a hydrogen atom or a low-grade alkyl group, and R<2> is a substitutional or nonsubstitutional alkyl group, a substitutional or nonsubstitutional alkenyl group, a substitional or nonsubstitutional aromatic ring, a substitutional or nonsubstitutional complex ring, or a substitutional or nonsubstitutional cycloalkyl group having an oxygen atom or a nitrogen atom in beta, gamma, delta positions in relation to a carbonyl group in the formula I. This results in obtaining the electrophotographic sensitized body provided with the intermediate layer having the function of enabling the coating of a durable protecting layer on the outside of the photosensitive layer without harming the photosensitive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor, and particularly to an intermediate layer when the photoreceptor has a protective layer.

[Prior Art] Electrophotographic photoreceptors are required to have the required sensitivity, electrical properties, and optical properties according to the electrophotographic process used. In some cases, electrical and mechanical external forces such as corona charging, toner development, transfer to transfer paper, and cleaning processing are directly applied to the surface layer of the photoreceptor, that is, the layer that is most isolated from the substrate. Durability is required. Specifically, durability is required against surface friction and scratches caused by rubbing, as well as surface deterioration due to ozone generated during corona charging.

On the other hand, there is also a problem of toner adhesion to the surface layer due to repeated toner development and cleaning, and to solve this problem, it is desired to improve the cleaning properties of the surface layer.

In particular, in the case of positively charging photoreceptors, the layer in the photoconductive layer that is most isolated from the conductive substrate is the charge generation layer, so the surface layer is mechanically and chemically weak, making it difficult to provide a protective layer. Very effective in terms of durability. In order to satisfy the characteristics required for the surface layer, attempts have been made to provide a surface protective layer mainly composed of resin. For example,
7-30843, a protective layer in which resistance is controlled by adding a metal oxide as a conductive powder has been proposed.

However, the conventional methods have problems with the dispersibility and cohesiveness of metal oxide particles in the binder resin, conductivity and transparency when used in the protective layer, and non-uniformity of the surface of the protective layer. , image defects due to unevenness, increased residual potential due to repeated charging, and decreased sensitivity were likely to occur.

When a protective layer is laminated on top of a photosensitive layer for positive charging, which has a charge transport layer and a charge generation layer laminated in this order on a substrate, the problem often arises that the sensitivity decreases significantly, making it difficult to put it into practical use. It was a hindrance.

[Problems to be Solved by the Invention] The present invention aims to provide an electrophotographic photoreceptor that meets the above-mentioned requirements. That is, an object of the present invention is to provide an electrophotographic photoreceptor having an intermediate layer that allows a protective layer to be coated on the photosensitive layer without damaging it.

By this improvement, it is possible to obtain an electrophotographic photoreceptor coated with a protective layer that has excellent slip properties and is durable against surface abrasion and scratches caused by rubbing. Another object of the present invention is to provide an electrophotographic photoreceptor that does not accumulate residual potential and can maintain high image quality in repeated electrophotographic processes. Still another object of the present invention is to provide an electrophotographic photoreceptor capable of forming images with no black dot-like image defects (hereinafter referred to as black dots) and no fog.

[Means for Solving the Problems] As a result of extensive studies by the present inventors in accordance with the above-mentioned objective, an electrophotographic photoreceptor having a photosensitive layer, an intermediate layer, and a protective layer on a conductive substrate in this order from the substrate side. Invented an electrophotographic photoreceptor in which the intermediate layer contains a polymer or copolymer having a unit component shown in the following formula [1], and which satisfies the above-mentioned requirements. were able to provide.

1,000 CH2-C+ 1 General formula [1] % formula % (In the formula, R' is a hydrogen atom or a lower alkyl group, and R2 is β with respect to the carbonyl group in the general formula [1].

Represents a substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aromatic ring, substituted or unsubstituted heterocycle, substituted or unsubstituted cycloalkyl group having an enzyme atom or nitrogen atom at the γ or δ position ).

Hereinafter, the content of the present invention will be explained in more detail.

The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a photoconductive layer, an intermediate layer, and a protective layer on a conductive substrate in this order from the substrate side.

Hereinafter, first, the protective layer will be explained.

In the protective layer of an electrophotographic photoreceptor, it is essential to control the resistance in view of chargeability, residual potential, sensitivity, etc. For this reason, attempts have been made in the past to control resistance by dispersing metal oxides in a binder resin in a protective layer.

Generally, when particles are dispersed in a protective layer, in order to prevent scattering of incident light by the dispersed particles, the particle size of the particles must be smaller than the wavelength of the incident light, that is, 0.3 μm or less. is necessary.

Examples of the resin used for the protective layer in the present invention include resins such as polycarbonate, polyester, phenol resin, polyethylene terephthalate, acrylic resin, polystyrene, cellulose, polyethylene, polypropylene, polyurethane, epoxy, silicone, and polyvinyl chloride. .

As a result of repeated studies to improve the dispersibility, abrasion resistance, and wound resistance of these fine particles, the present inventors found that they contain a monomer having a curable ethylenic double bond, especially an acrylic monomer. It has been found that when ultrafine particles of a metal oxide are dispersed in a resin, excellent effects are exhibited in all of the dispersibility of the particles, abrasion resistance, and scratch resistance.

The conductive metal oxide used in the present invention includes zinc oxide,
titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide,
Ultrafine particles of tin oxide, zirconium oxide, etc. doped with antimony can be used. These metal oxides may be used alone or in combination of two or more. When two or more types are mixed, they may be in the form of a solid solution or fusion.

The above-mentioned curable acrylic monomer has the following general formula [2]
It is a compound with an acrylic functional group represented by

R-0-C-CH=CH2 or 0CH, (2) R-0-C-C=CH2 These acrylic monomers may be used alone or in combination with other polyesters, polycarbonates, polystyrene, cellulose, polyethylene, It may be mixed with commercially available resins such as polypropylene, polyurethane, acrylic, epoxy, silicone, and polyvinyl chloride.

In the present invention, additives such as a coupling agent and an antioxidant may be added to the protective layer for the purpose of improving dispersibility, binding properties, and weather resistance. The purpose of the protective layer is to provide an electrophotographic photoreceptor that can obtain images without fog due to the metal oxide contained in the binder resin.

However, while a protective layer made of a resin containing a -1 curable acrylic monomer satisfies both the dispersibility of fine particles and the properties of abrasion resistance and scratch resistance, when it is formed on the photosensitive layer, it corrodes the photoreceptor and increases sensitivity. It has been found that there is a drawback in that it causes deterioration. This deterioration in sensitivity was particularly noticeable in positively charging photoreceptors having a charge generation layer as an upper layer.

As a method for dealing with this problem, the present inventors discovered that it is effective to provide an intermediate layer between the photosensitive layer and the protective layer, and established an optimal formulation for the intermediate layer.

Next, Table 1 shows examples of resins for the intermediate layer actually used in the present invention.

Table 1 The electrophotographic photoreceptor of the present invention contains the above-mentioned resin in the intermediate layer between the photosensitive layer and the surface protective layer, so that it acts as a barrier layer for the photosensitive layer when forming the protective layer, and the protective layer After the film is formed, it acts as an adhesive layer between the photosensitive layer and the protective layer.

The resin for the intermediate layer used in the present invention is prepared by dissolving monomers corresponding to the unit components represented by the general formula [1] in a suitable solvent, and adding a radical initiator such as azobisisobutyronitrile (AIBN) or benzoyl peroxide. Alternatively, it can be produced by adding an ionic polymerization initiator such as metallic sodium.

Further, since impurities such as initiator residues often remain in the produced intermediate layer resin, it is preferable to add purification steps such as reprecipitation and washing before use.

Next, a specific manufacturing example of the resin example [1] will be shown as the resin used for forming the intermediate layer constituting the electrophotographic photoreceptor of the present invention.

<Production Example> Dissolve 60 g of the following compound obtained by condensing methyl methacrylate and acetone in the presence of sodium methylate, 8 g of Hs AIBNo, in 100 g of methanol,
The mixture was heated and stirred at 0° C. for 12 hours to carry out a polymerization reaction.

Next 1. Add 250 ml of acetone to the reaction mixture cooled to room temperature.
After adding g, reprecipitation purification was performed in demineralized water. Thereafter, vacuum drying was performed to obtain 28 g of resin (1) (see Table 1).

The intermediate layer of the present invention may be composed of the resin represented by the above-mentioned general formula [1] alone, or may be composed of a system in which other resins, additives, and conductive substances are added as necessary.

The structure of the photoconductive layer of the electrophotographic photoreceptor of the present invention may be either a single-layer type containing both a charge-generating substance and a charge-transporting substance, or a multilayer type in which a charge-generating layer and a charge-transporting layer are laminated on a conductive substrate. The laminated type photoreceptor will be explained below.

The structure of the laminated type photosensitive layer includes one in which a charge generation layer and a charge transport layer are laminated in this order on a conductive substrate, and one in which a charge transport layer and a charge generation layer are laminated in this order on a conductive substrate.

If the support used in the present invention has conductivity,
Any type of material (for example, metal such as aluminum, copper, chromium, nickel, zinc, stainless steel, etc., molded into a drum or sheet shape, metal foil such as aluminum or copper laminated to a plastic film, aluminum, oxidized Examples include plastic films on which indium, tin oxide, etc. are vapor-deposited, metals on which conductive layers are provided by coating a conductive substance alone or together with a binder resin, plastic films, and paper.

The charge transport layer of the laminated photoreceptor is made of a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene, or phenanthrene in the main chain or side chain, or a nitrogen-containing ring compound such as indole, carbazole, oxadiazole, or pyrazoline. It is formed using a coating liquid in which a charge transporting substance such as a hydrazone compound or a styryl compound is dissolved in a resin that has film-forming properties.

Examples of resins with such film-forming properties include polyester,
Examples include polycarbonate, polystyrene, polymethacrylate, and the like. The thickness of the charge O transport layer is 5 to 4
0 um, preferably 10 to 30 μm.

The charge-generating layer of the laminated photoreceptor contains charge-generating substances such as sudan red, quinone pigments, quinicyanine pigments, perylene pigments, indigo and thioindigo, and phthalocyanine pigments, as well as polyvinyl butyral, polystyrene, and polyvinyl acetate. The pigment is dispersed in a binder resin such as an acrylic resin, and this dispersion is applied, and the pigment is formed by vacuum vapor deposition.

The thickness of such a charge generation layer is 5 μm or less, preferably 0.05 to 3 μm.

In the present invention, an intermediate layer having a barrier function and an adhesive function may be provided between the conductive layer and the photosensitive layer. The intermediate layer can be formed from casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, alcohol-soluble amide, polyurethane, gelatin, and the like. The thickness of the intermediate layer is suitably 0.1 μm to 3 μm.

As described above, in the electrophotographic photoreceptor of the present invention, a resin layer of a polymer or copolymer represented by the general formula [1] is provided as an intermediate layer on a photosensitive layer, and a conductive metal oxide layer is further provided thereon. This is an electrophotographic photoreceptor that has a protective layer in which ultrafine particles are dispersed.

Therefore, in the present invention, a homogeneous protective layer with high hardness and good dispersibility of conductive fine particles could be formed without damaging the photosensitive layer. As a result, it has become possible to provide an electrophotographic photoreceptor that is free from image defects such as unevenness, fogging, and black spots, has very high wear resistance and scratch resistance, and has good sensitivity.

Furthermore, in the present invention, since there is no deterioration of the photoreceptor due to charging failure, it is possible to provide a photoreceptor without image defects even after repeated durability tests.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in a wide range of electrophotographic applications such as laser beam printers, CRT printers, LED printers, liquid crystal printers, laser plate making, and facsimile printers. I can do it.

FIG. 1 shows a schematic configuration of a general transfer type electrophotographic apparatus using a drum type photoreceptor equipped with the electrophotographic photoreceptor of the present invention.

In FIG. 1, reference numeral 11 denotes a drum-type photoreceptor as an image bearing member, which is rotated at a predetermined circumferential speed in the direction of the arrow around a shaft 11a. During the rotation process, the photoreceptor 11 is uniformly charged to a predetermined positive or negative potential on its circumferential surface by the charging means 12, and then in the exposure section 13, it is exposed to a slit by an image exposure means (not shown). exposure, laser beam scanning exposure, etc.). As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the circumferential surface of the photoreceptor.

The electrostatic latent image is then developed with toner by the developing means 14,
The toner developed image is sequentially transferred by the transfer means 15 onto the surface of the transfer material P that is fed from a paper feeding section (not shown) between the photoreceptor 11 and the transfer means 15 in synchronization with the rotation of the photoreceptor 11. be done.

The transfer material P that has undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 18, where the image is fixed, and is printed out outside the machine as a copy.

After the image has been transferred, the surface of the photoreceptor 11 is cleaned by a cleaning means 16 to remove residual toner and is repeatedly used for image formation.

As the uniform charging means 12 for the photoreceptor 11, a corona charging device is generally widely used. Further, as the transfer device 15, corona transfer means is widely and generally used. The electrophotographic apparatus is constructed by combining a plurality of components such as the photoreceptor 11, developing means 14, and cleaning means 16 described above into an apparatus unit, and this unit is detachable from the apparatus main body. It may be configured as follows.

For example, the photoreceptor 41 and the cleaning means 16 may be integrated into a single device unit, and configured to be detachable using a guide means such as a rail on the main body of the device. At this time, the above-mentioned device unit may be configured to include the charging means 12 and/or the developing means 14.

Furthermore, when using an electrophotographic device as a copying machine or printer, optical image exposure involves reading the reflected light, transmitted light, or the document from the document and converting it into a signal, which scans the laser beam and drives the light emitting diode array. Alternatively, this may be performed by driving a liquid crystal shutter array or the like.

Furthermore, when used as a facsimile printer, the optical image exposure is exposure for printing received data. FIG. 2 is a block diagram showing an example of this case.

In FIG. 2, the controller 21 is the image reading section 2.
0 and printer 29. The entire controller 21 is controlled by a CPU 27. The read data from the image reading section is transmitted to the other party's station through the transmitting circuit 23.

Data received from the partner station is sent to the printer 29 through the receiving circuit 22. Image memory 26 stores predetermined image data. A printer controller 28 controls a printer 29. 24 is a telephone.

Images received from the line 25 (image information from a remote terminal connected via the line) are demodulated by the receiving circuit 22, and then decoded by the CPU 27 and sequentially stored in the image memory 26. Ru. Then, when at least one page worth of images is stored in the image memory 26, the image recording of that page is performed. The CPU 27 reads one page's worth of image information from the image memory 26 and sends the decoded one page's worth of image information to the printer controller 28 . When the printer controller 28 receives one page of image information from the CPtJ 27, it controls the printer 29 to record the image information of that page. In addition, CPU27
The next page is being received while the printer 29 is recording.

As described above, an electrophotographic apparatus equipped with the image holding member of the present invention can be used as a printer to receive and record images.

The present invention will be explained in more detail below with reference to specific examples.

Example 1 On an aluminum cylinder (φ30 mm x 260 mm), 10 parts of alcohol-soluble copolymerized nylon resin (average molecular weight 29,000) and 30 parts of methoxymethylated 6 nylon resin (average molecular weight 32,000) were mixed with 260 parts of methanol and 40 parts of butanol. A prepared solution dissolved in a mixed solvent was applied by dip coating to form an intermediate layer having a thickness of 0.5 μm.

Next, 10 parts of a styryl compound having the following structural formula and 10 parts of polycarbonate (weight average molecular weight 40,000) were dissolved in a mixed solvent of 20 parts of dichloromethane and 40 parts of monochlorobenzene, and this solution was dip-coated onto the above intermediate layer. , dried at 120°C for 60 minutes to form a film with a thickness of 20 am.
A charge transport layer was formed.

Next, 4 parts of the disazo face amount shown by the following structural formula, 2 parts of polyvinyl butyral (degree of butyralization 68%, weight average molecular weight 28,000) and 34 parts of cyclohexanone were mixed and dispersed in a sand mill for 12 hours, and then tetrahydrofuran was added. (THF)60
A dispersion liquid for a charge generation layer was prepared by adding 50% of the dispersion liquid. This dispersion was spray-coated onto the charge transport layer and heated at 80°C for 20 minutes.
It was dried for minutes to form a charge generation layer with a thickness of 0.20 μm.

Next, as a coating liquid for the intermediate layer, 6 parts of the polymer (1) shown in Table 1 above was dissolved in 95 parts of DMF to prepare a paint for the intermediate layer.

This paint was spray coated on the charge generation layer to a film thickness of 1
．． An intermediate layer of 0 μm was formed.

Next, the following structural formula CH, OR.

CH, CH-C-CI (20R.

C1, OR.

60 parts of a curable acrylic monomer represented by [herein, R,: -C-CH-CHa], 30 parts of ultrafine tin oxide particles (average particle size: 40'O) before dispersion, 2 as a photopolymerization initiator. -0.1 part of methylthioxanthone and 300 parts of toluene were mixed and dispersed in a sand mill for 48 hours. This mixture was used to form a film on the intermediate layer using a spray coating method, and after drying, it was heated to 8 mW/cm2 using a high-pressure mercury lamp.
A protective layer was obtained by irradiating ultraviolet light at a light intensity of 8 for 25 seconds.

The electrophotographic photoreceptor produced in this manner was installed in a regular development type copying machine that repeats the process of charging, exposure, development, transfer, and cleaning in cycles of 1.5 seconds, and the electrophotographic characteristics were evaluated at room temperature. Furthermore, the image was subjected to a durability test of 10,000 times. As a result, Comparative Example 1
Compared to the photoreceptor without an intermediate layer or protective layer shown in , both sensitivity and residual potential were stable, and images without unevenness or black spots could be obtained. Furthermore, stable images could be continuously created even after 10,000 repeated image outputs. The results are shown in Table 2.

Examples 2 to 5 Each polymer resin (2) exemplified in Table 1 as an intermediate layer coating material
Electrophotographic photoreceptors were prepared in the same manner as in Example 1 except that , (3), (6), and (8) were used, respectively, and named as Examples 2 to 5, respectively.

When these photoreceptors were evaluated in the same manner as in Example 1, the sensitivity and residual potential were stable, and good images without unevenness or black spots could be obtained. The results are shown in Table 2.

Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1, except that the intermediate layer and protective layer of Example 1 were omitted, and the same evaluation was performed. As a result, as shown in Table 2, the initial electrophotographic properties were good, but after 300 sheets of durable use, the charge generation layer on the surface was scraped off, and good images could no longer be obtained.

Comparative Example 2 A photoreceptor was produced and evaluated in the same manner as in Example 1 except that the intermediate layer of Example 1 was omitted. As a result, as shown in Table 2, the initial electrophotographic sensitivity was extremely low.

Comparative Example 3 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the intermediate layer in Example 1 was spray-coated with a film of polycarbonate (weight average molecular weight 35,000) 1.0 urn. As a result, as shown in Table 2, the initial residual potential was very high and fog occurred in the background of the image.

Example 6 An intermediate layer was provided on an aluminum cylinder in the same manner as in Example 1. Next, 10 parts of a charge transport material having the following structural formula and a polycarbonate cap (average molecular weight 22,000) 1
0 parts, 20 parts of dichloromethane, 40 parts of monochlorobenzene
This solution was applied onto the undercoat layer by dip coating and dried at 120"C for 60 minutes to obtain a film thickness of 20LL.
A charge transport layer of m was formed. Next, 4 parts of a disazo pigment with the following structural formula, 2 parts of polyvinylbenzal (benzal conversion rate: 80%, weight average molecular weight: 1.1000), and 3 parts of cyclohexane.
After mixing and dispersing 0 parts for 12 hours using a sand mill, 60 parts of methyl ethyl ketone was added to prepare a dispersion liquid for a charge generation layer. This dispersion was spray coated onto the charge transport layer and dried for 80'' Cl2O to form a charge generation layer of 0.0 .mu.m.

An intermediate layer and a protective layer were formed on this charge generation layer in the same manner as in Example 5 to obtain a photoreceptor.

The electrophotographic photoreceptor produced in this way was installed in a reversal development type laser printer that repeats the process of charging, laser exposure, development, transfer, and cleaning in a 1.5 second cycle, and the electrophotographic properties were evaluated. 1000
Durability surface leveling was performed 0 times. As a result, the sensitivity, power and residual potential were stable, and images without unevenness or black spots could be obtained. The results are shown in Table 2.

Examples 7 and 8 An electrophotographic photoreceptor was prepared in the same manner as in Example 6, except that modified polyamide resins (11) and (12) listed in Table 1 were used as intermediate layer coatings. Examples 7 and 8 were prepared.

When each of these photoreceptors was evaluated in the same manner as in Example 6, the sensitivity and residual potential were stable, and the images were good with no defects. The results are shown in Table 2.

Comparative Example 4 Example 6 except that the intermediate layer was removed from the photoreceptor of Example 6.
A photoreceptor was prepared in the same manner as above, and the evaluation was negative. As a result, as shown in Table 2, the initial electrophotographic sensitivity was very low.

[Effects of the Invention] The intermediate layer of the present invention functions to enable a durable protective layer to be coated on the outside of the photosensitive layer in an electrophotographic photoreceptor without damaging it. That is, by interposing the intermediate layer of the present invention, it is possible to use as a coating material a material that can form a durable layer that has excellent slip properties as a protective layer and is resistant to abrasion and scratches on the surface due to rubbing. can.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a transfer copying machine equipped with the electrophotographic photoreceptor of the present invention, and FIG. 2 is a block diagram of a facsimile system using the electrophotographic photoreceptor of the invention as a printer. [Main symbols in the diagram] 11...Drum type photoreceptor 12...Charging means 13...Exposing section 14...Developing means 15...Transfer means 16...Cleaning means 18... Image fixing means L...Light image exposure P...Transfer material agent Patent attorney Sekihei Yamashita

Claims (6)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer, an intermediate layer, and a protective layer on a conductive substrate in this order from the substrate side, the intermediate layer is a polymer or copolymer having a unit component represented by the following general formula [1]. Electrophotographic photoreceptor characterized by containing a combination: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula [1] (In the formula, R^1 is a hydrogen atom or a lower alkyl group, and R^2 is a general formula [1] A substituted or unsubstituted alkyl group having an oxygen atom or nitrogen atom at the β, γ, or δ position relative to the carbonyl group in [1],
substituted or unsubstituted alkenyl group, substituted or unsubstituted aromatic ring, substituted or unsubstituted heterocycle, substituted or unsubstituted cycloalkyl group). (2) The electrophotographic photoreceptor according to item 1, wherein the photosensitive layer is a positively charging photosensitive layer comprising a charge transport layer and a charge generation layer laminated in this order. (3) An electrophotographic apparatus comprising an electrophotographic photoreceptor, a latent image forming means, a means for developing the formed latent image, and a means for transferring the developed image to a transfer material, wherein the electrophotographic photoreceptor is the one according to claim 1. An electrophotographic device characterized by being as described in . (4) The electrophotographic photoreceptor according to claim 1 and at least one of the charging means, the developing means, and the cleaning means are integrally supported to form a unit, and the single unit is detachably attached to the main body of the apparatus. Characteristic electrophotographic device unit. (5) An electrophotographic apparatus comprising the electrophotographic photoreceptor according to claim 1, a latent image forming means, a means for developing the formed latent image, and a means for transferring the developed image onto a transfer material. (6) The electrophotographic photoreceptor according to claim 1, an electrophotographic apparatus comprising a latent image forming means and a means for transferring a developed image to a transfer material, and a receiving means for receiving image information from a remote terminal. A facsimile machine featuring