JP2004199043A - Electrophotographic device, process cartridge, and electrophotographic photoreceptor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an electrophotographic device whose beam spot is made small in diameter by using a laser beam of 380 to 450 nm in oscillation wavelength to output an image of superhigh resolution and superhigh picture quality. <P>SOLUTION: The electrophotographic device has the electrophotographic photoreceptor having a photosensitive layer on a cylindrical base, an electrophotographic photoreceptor unit having fitted member fitted to an end of the electrophotographic photoreceptor, and an exposure means having a laser of 380 to 450 nm in oscillation wavelength. The spot diameter (Di [μm]) of the beam formed on the surface of the electrophotographic photoreceptor with a laser beam emitted by the laser is ≤40 μm, and cylinder deflection (De [μm]) of the electrophotographic photoreceptor unit is ≤1.5 time as large as the spot diameter (Di [μm]) of the beam spot. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an electrophotographic apparatus, a process cartridge, and an electrophotographic photosensitive member unit.

Conventionally, various methods such as an electrophotographic method, a thermal transfer method, and an ink jet method have been adopted for an image forming apparatus. Among these, an image forming apparatus employing an electrophotographic method, a so-called electrophotographic apparatus, has advantages in terms of high speed, high image quality, and quietness as compared with image forming apparatuses employing other methods. I have.
Further, not only monochrome electrophotographic apparatuses, but also multi-color (color) electrophotographic apparatuses (color electrophotographic apparatuses) have become widespread.

  There are various types of color electrophotographic apparatuses. For example, exposure and development are sequentially performed one color at a time with one electrophotographic photosensitive member, and a toner image of each color is placed on an intermediate transfer member (intermediate transfer drum, intermediate transfer belt, etc.). The primary transfer is performed sequentially to the transfer material, and then the secondary transfer is performed collectively on the transfer material to form an intermediate transfer method, or an image forming unit for each color arranged in series (electrophotographic photosensitive member, charging Means, exposing means, developing means, transferring means, etc.), each of which forms a toner image of each color, and these are transferred onto a transfer material sequentially transferred to each image forming section by a transferring material transferring member (such as a transferring material transferring belt). Or an in-line method of forming a color image by sequentially transferring the toner image onto a transfer material holding member (such as a transfer drum). Transfer medium are well known and multiple transfer method which forms a color image by sequentially transferred onto (paper, etc.).

  In recent years, various approaches have been taken in response to the growing need for ultra-high resolution and ultra-high image quality in electrophotographic apparatuses. Among various approaches, the relationship between an electrophotographic photoreceptor and an exposure unit for forming an electrostatic latent image on the surface of the electrophotographic photoreceptor is considered to be particularly important because it is fundamental to image formation. ing. For example, Japanese Patent No. 3254833 (Patent Document 1) discloses that in a system using a laser beam as exposure light (image exposure light), a writing pitch of the laser beam and a cylindrical electrophotographic photosensitive member (photosensitive drum) are used. The relationship with the overall swing is described.

  However, no matter how small the writing pitch of the laser beam is, unless the spot diameter (beam spot diameter) of the beam spot formed on the surface of the electrophotographic photosensitive member by the laser beam is reduced, ultra-high resolution and ultra-high image quality are achieved. Images cannot be obtained.

  The spot diameter of a beam spot formed on the surface of an electrophotographic photosensitive member by a laser beam emitted from a laser (near infrared semiconductor laser) having an oscillation wavelength of about 780 nm, which has been conventionally used as an exposure light source of an electrophotographic apparatus. Is about 100 μm, and even if various optical members are improved, the limit is about 50 to 80 μm.

Further, it is known from the diffraction limit of the laser beam shown in the following equation (1) that even if the spot diameter of the beam spot is reduced by improving the optical member, it is difficult to obtain a clear outline of the beam spot. Formula (1) is, (numerical aperture N _A lens) which has shown that the lower limit is proportional to the wavelength of the laser beam (lambda) of the beam spot of the spot diameter (D).
D = 1.22λ / N _A (1)

Therefore, in recent years, it has been considered to use a laser (blue semiconductor laser) having a short oscillation wavelength, which has been put into practical use in DVDs and the like, as an exposure light source for an electrophotographic apparatus (Japanese Patent Laid-Open No. 9-240051 (Patent Document 2)). )Such).
When a laser having an oscillation wavelength in the range of 380 to 450 nm is used as the exposure light, the spot diameter of the beam spot can be considerably reduced (40 μm or less) while maintaining the sharpness of the contour of the beam spot. Therefore, ultra-high resolution is achieved, which is extremely advantageous for ultra-high image quality.

Japanese Patent No. 3254833 JP-A-9-240051

  Generally, a member for rotating and driving the electrophotographic photosensitive member in an electrophotographic apparatus is fitted to both ends of the cylindrical electrophotographic photosensitive member. Examples of members (fitting members) fitted to both ends of the electrophotographic photosensitive member include a gear as a driving member and a flange as a bearing member.

  In an electrophotographic apparatus in which the spot diameter of a beam spot is reduced (40 μm or less) using a laser having an oscillation wavelength in a range of 380 to 450 nm, a so-called electronic device in which fitting members are fitted to both ends of an electrophotographic photosensitive member. Very high precision is required for the photoreceptor unit.

  If the accuracy of the electrophotographic photoreceptor unit is poor, the amount of change in the distance (image formation distance) between the electrophotographic photoreceptor and the exposure means increases, so that a beam spot is formed on the surface of the electrophotographic photoreceptor during laser beam irradiation. It is difficult to form accurately, and image roughness (unevenness of halftone image, roughness) is likely to occur.

  Further, if the accuracy of the electrophotographic photoreceptor unit is low, the amount of change in the gap or nip pressure between the electrophotographic photoreceptor and a developing member (e.g., a developing roller or a developing sleeve) becomes large during development, so In the case of roughness (non-uniformity of halftone images, roughness) or color image output, color misalignment is likely to occur. In addition, at the time of transfer, the positional accuracy between the electrophotographic photosensitive member and the transfer member or transfer paper becomes insufficient, so that color misregistration tends to occur in the case of color image output.

  However, there is no prior art that focuses on the accuracy of the electrophotographic photosensitive member unit in order to solve such problems. In other words, even with an electrophotographic apparatus in which the beam spot diameter of a beam spot is reduced using a laser having an oscillation wavelength in the range of 380 to 450 nm, an ultra-high resolution and ultra-high quality image output is currently required. Was not enough.

  SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems in an electrophotographic apparatus in which the spot diameter of a beam spot is reduced by using a laser having an oscillation wavelength in a range of 380 to 450 nm, and to output an ultra-high resolution and ultra-high quality image. Another object of the present invention is to provide an electrophotographic apparatus capable of performing the above-mentioned, and to provide a process cartridge and an electrophotographic photosensitive member unit used in the electrophotographic apparatus.

The present inventors have conducted intensive studies to solve the above-described problems, and as a result, in an electrophotographic apparatus in which a laser beam having an oscillation wavelength in a range of 380 to 450 nm and a spot diameter of a beam spot is reduced, an electrophotographic photosensitive member is used. As the accuracy of the unit, it was found that the cylindrical runout was most closely related to the above-mentioned problem, and easily affected the super-high-resolution and super-high-quality image output.
In addition, the present inventors have found that an ultra-high-resolution, ultra-high-quality image output is possible only when the cylindrical deflection of the electrophotographic photosensitive member unit has a fixed relationship with the spot diameter of the beam spot. I found it.

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support, an electrophotographic photosensitive member unit having a fitting member fitted to an end of the electrophotographic photosensitive member, and an oscillation wavelength of 380. Exposure means having a laser in the range of 450 nm to 450 nm, and a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam emitted from the laser is 40 μm or less. In an electrophotographic apparatus,
An electrophotographic apparatus, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 1.5 times or less a spot diameter (Di [μm]) of the beam spot.

Further, the present invention is a process cartridge having an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support and an electrophotographic photosensitive member unit having a fitting member fitted to an end of the electrophotographic photosensitive member. hand,
An exposure unit having a laser having an oscillation wavelength in a range of 380 to 450 nm, and a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam emitted from the laser. In a process cartridge detachable from an electrophotographic apparatus having a size of 40 μm or less,
A process cartridge characterized in that the cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 1.5 times or less the spot diameter (Di [μm]) of the beam spot.

Further, the present invention is an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support, and an electrophotographic photosensitive member unit having a fitting member fitted to an end of the electrophotographic photosensitive member,
An exposure unit having a laser having an oscillation wavelength in a range of 380 to 450 nm, and a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam emitted from the laser. In an electrophotographic photoreceptor unit used for an electrophotographic apparatus having a
An electrophotographic photoreceptor unit, wherein a cylindrical deflection (De [μm]) of the electrophotographic photoreceptor unit is 1.5 times or less the spot diameter (Di [μm]) of the beam spot.

  ADVANTAGE OF THE INVENTION According to the present invention, in an electrophotographic apparatus in which a laser beam having an oscillation wavelength in a range of 380 to 450 nm and a spot diameter of a beam spot is reduced, an electrophotographic apparatus capable of outputting an image with ultra-high resolution and ultra-high image quality is provided. And a process cartridge and an electrophotographic photoreceptor unit used in the electrophotographic apparatus can be provided.

Hereinafter, the present invention will be described in more detail.
First, a method for measuring the spot diameter (Di [μm]) of a beam spot according to the present invention will be described with reference to FIG.

In the present invention, when the peak intensity is A, the spot diameter of the beam spot is represented by a portion until the intensity decreases to A × 1 / e ² . Note that the intensity distribution includes a Gaussian distribution, a Lorentz distribution, and the like.
The spot diameter of the beam spot was measured at nine points where the image forming area was divided into eight in the longitudinal direction, and the average value of the nine points was used as the spot diameter of the beam spot (Di [μm]).
In general, the shape of the beam spot is often elliptical as shown in FIG. Therefore, the spot diameter of the beam spot at each measurement point was an average value of the spot diameter D1 in the main scanning direction (longitudinal direction) and the spot diameter D2 in the sub-scanning direction (circumferential direction).
In the present invention, the measurement of the spot diameter D1 in the main scanning direction and the spot diameter D2 in the sub-scanning direction of the beam spot were both performed using a beam analyzer manufactured by Meles Griot Co., Ltd.

  In the present invention, the spot diameter (Di [μm]) of the beam spot measured as described above must be 40 μm or less.

Next, a method for measuring the cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit according to the present invention will be described with reference to FIG. FIG. 2 is a diagram showing a schematic configuration of the cylindrical runout measuring device.
In FIG. 2, the electrophotographic photosensitive member unit 201, which is an object to be measured, is fixed by the driving-side receiving jig 205 and the driven-side receiving jig 206 by moving the slide base 207 in the direction of the arrow. The distance between the reference gauge 202 manufactured with ultra-high accuracy and the electrophotographic photosensitive member unit 201 is measured by a laser beam 203 installed above the electrophotographic photosensitive member unit 201.

  The measurement of the distance between the reference gauge 202 and the electrophotographic photoreceptor unit 201 in the longitudinal direction is performed by moving the base 204 itself installed on a surface plate (not shown) via a linear guide (not shown) in the direction of the arrow. Do. The measurement of the distance between the reference gauge 202 and the electrophotographic photoconductor unit 201 in the circumferential direction is performed by rotating the electrophotographic photoconductor unit 201 in the direction of the arrow by the rotating device 208. In both the longitudinal direction and the circumferential direction, the measurement is performed with the laser fixed.

The measurement of the cylindrical runout of the electrophotographic photoreceptor unit was performed at nine points obtained by dividing the image forming area into eight parts in the longitudinal direction and eight points obtained by dividing the image forming area into eight parts at 45 ° intervals in the circumferential direction. The difference between the maximum value and the minimum value was determined as the cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit. This value is calculated by a data processing device (not shown).
The driving-side receiving jig 205 and the driven-side receiving jig 206 are respectively adapted to fitting members (gear as a driving member and flange as a bearing member) fitted to both ends of the electrophotographic photosensitive member. What is necessary is just to have a shape.

  The cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit measured as described above is 1.5 times or less the spot diameter (Di [μm]) of the beam spot measured as described above ( If De / Di ≦ 1.5), the amount of change in the distance (imaging distance) between the electrophotographic photosensitive member and the exposure means is small, so that a beam spot is formed on the surface of the electrophotographic photosensitive member during laser beam irradiation. Can be formed accurately.

Furthermore, during development, the gap between the electrophotographic photoreceptor and the developing member (developing roller or developing sleeve) or the amount of change in the nip pressure is small, so that image unevenness due to development unevenness (non-uniformity of halftone images, roughness ) And color image output, no color shift occurs. Further, at the time of transfer, since the positional accuracy between the electrophotographic photosensitive member and the transfer member or the transfer paper is sufficient, color shift does not occur in the case of color image output.
Therefore, super-high resolution and super-high quality image output is possible.

Further, the cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is preferably 1.0 times or less (De / Di ≦ 1.0) of the spot diameter (Di [μm]) of the beam spot, More preferably, it is 0.5 times or less (De / Di ≦ 0.5).
As a method of reducing the cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit, there is a method of improving the accuracy of the electrophotographic photosensitive member, for example, a method of reducing the cylindrical deflection of the electrophotographic photosensitive member. Further, there is a method of improving the accuracy of the bonding portion between the electrophotographic photosensitive member and the fitting member, the accuracy of the fitting member with respect to the drive shaft, and the like.

  As a method of improving the accuracy of the electrophotographic photosensitive member, there is a method of improving the accuracy of the cylindrical support of the electrophotographic photosensitive member, for example, a method of reducing the deflection of the cylindrical support of the electrophotographic photosensitive member. . Specifically, a method of increasing the thickness of the cylindrical support, cutting the inside of both ends of the cylindrical support, cutting the surface of the cylindrical support, and the like are mentioned.

  Methods for improving the accuracy of the bonding portion between the electrophotographic photosensitive member and the fitting member include cutting the inside of both ends of the cylindrical support, narrowing the tolerance of the bonding portion of the fitting member, and cutting the inner and outer diameters simultaneously with a cutting tool. For example, using a fitted member (flange).

  As a method for improving the accuracy of the fitting member with respect to the drive shaft, there is a method of increasing the coaxiality between the fitting member and the drive shaft.

  The measurement of the cylindrical runout of the electrophotographic photosensitive member and the cylindrical runout of the cylindrical support is performed in the same manner as the above-described measuring method of the cylindrical runout of the electrophotographic photosensitive member unit. The body or the cylindrical support may be the object to be measured. In this case, the driving-side receiving jig 205 and the driven-side receiving jig 206 may have shapes that are adapted to both ends of the electrophotographic photosensitive member and both ends of the cylindrical support, respectively.

Hereinafter, the configuration of the electrophotographic photosensitive member used in the present invention will be described.
As described above, the electrophotographic photosensitive member used in the present invention is an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support. Hereinafter, the cylindrical support is simply referred to as a support.

Even if the photosensitive layer is a single-layer type photosensitive layer containing a charge transporting substance and a charge generating substance in the same layer (FIG. 3A), it contains a charge generating layer containing a charge generating substance and a charge transporting substance. It may be a laminated (functionally separated) photosensitive layer separated from the charge transporting layer, but a laminated photosensitive layer is preferred from the viewpoint of electrophotographic characteristics. The laminated photosensitive layer is composed of a forward-type photosensitive layer (FIG. 3B) in which a charge generation layer and a charge transport layer are laminated in this order from the support side, and a charge transport layer and a charge generation layer in order of the support side. Although there is a reverse layer type photosensitive layer (FIG. 3C), a forward layer type photosensitive layer is preferable from the viewpoint of electrophotographic characteristics.
3 (a), 3 (b) and 3 (c), 301 denotes a support, 302 denotes a photosensitive layer, 303 denotes a charge generation layer, and 304 denotes a charge transport layer.

The support may have conductivity, for example, a metal (alloy) such as aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum. Support can be used. In addition, a support made of the above metal (alloy) or a support made of a plastic (eg, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, or an acrylic resin) having a layer in which these metals are formed by vacuum deposition can also be used. . In addition, the metal support or the plastic support in which conductive particles such as carbon black and silver particles are coated with a suitable binder resin, and the conductive particles are impregnated in a plastic or paper with a suitable binder resin. A support or a plastic containing a conductive binder resin can also be used.
Further, as described above, the support preferably has a small cylindrical runout of the support itself in order to suppress the cylindrical runout of the electrophotographic photosensitive member unit.

  On the support, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering of laser light or the like, or covering a scratch on the support. The conductive layer can be formed by dispersing conductive particles such as metal particles and metal oxide particles in a binder resin. The thickness of the conductive layer is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more, while it is preferably 40 μm or less, and more preferably 30 μm or less. preferable.

  Further, an intermediate layer having a barrier function or an adhesive function may be provided between the support or the conductive layer and the photosensitive layer (charge generation layer, charge transport layer). The intermediate layer is formed for the purpose of improving the adhesiveness of the photosensitive layer, improving the coating property, improving the charge injection property from the support, protecting the photosensitive layer against electrical breakdown, and the like. The intermediate layer can be formed using materials such as polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, glue, and gelatin. The thickness of the intermediate layer is preferably 0.05 to 5 μm, and more preferably 0.2 to 3.0 μm.

  The charge generating substance used in the electrophotographic photoreceptor used in the present invention has an absorption in a wavelength range of 380 to 450 nm, and has a sensitivity required for obtaining a super-high resolution and super-high quality full-color image. It is preferable to use phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine and azo pigments such as monoazo, disazo and trisazo alone or as a mixture of two or more. Also, cationic dyes such as pyrylium dyes, thiapyrylium dyes, azulhenium dyes, thiacyanine dyes, quinocyanine dyes, etc .; A pigment, a quinacridone pigment, a perylene pigment, or the like may be used.

  When the photosensitive layer is a laminated photosensitive layer, as the binder resin used for the charge generation layer, for example, polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulose resin, acrylic resin, polyurethane, and the like Is mentioned. These resins may have a substituent, and the substituent is preferably a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyano group, a trifluoromethyl group, or the like. These can be used alone, as a mixture or as a copolymer, alone or in combination of two or more. Further, the amount of the binder resin used is preferably 80% by mass or less, more preferably 60% by mass or less, based on the total mass of the charge generation layer.

  The charge generation layer can be formed by applying a charge generation layer coating solution obtained by dispersing a charge generation substance together with a binder resin and a solvent, followed by drying. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, a roll mill, and the like. The ratio between the charge generating substance and the binder resin is preferably in the range of 1: 0.1 to 1: 4 (mass ratio), and particularly preferably in the range of 1: 0.3 to 1: 4 (mass ratio). .

  The solvent used in the coating solution for the charge generation layer is selected from the solubility and dispersion stability of the binder resin and the charge generation material to be used, for example, tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, and the like. Ethers, ketones such as cyclohexanone, methyl ethyl ketone, and pentanone; amines such as N, N-dimethylformamide; esters such as methyl acetate and ethyl acetate; aromatics such as toluene, xylene, and chlorobenzene; -Alcohols such as propanol, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene.

  When applying the coating solution for the charge generation layer, for example, an application method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, and a blade coating method can be used.

  Further, the thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 to 2 μm.

  In addition, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers, thickeners, and the like can be added to the charge generation layer as needed.

  Examples of the charge transporting substance used in the electrophotographic photoreceptor used in the present invention include 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil, tetracyanoquinodimethane and the like. Electron-withdrawing substances and electron transporting substances such as those obtained by polymerizing these electron-withdrawing substances, or polycyclic aromatic compounds such as pyrene and anthracene; carbazole compounds; indole compounds; oxazole compounds; thiazole compounds; Heterocyclic compounds such as diazole compounds, pyrazole compounds, pyrazoline compounds, thiadiazole compounds, and triazole compounds; hole transport materials such as hydrazone compounds, styryl compounds, benzidine compounds, triarylmethane compounds, and triphenylamine compounds. Is mentioned. These can be used alone or in combination of two or more.

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge transport layer include acrylic resin, polyarylate, polycarbonate, polyester, polystyrene, acrylonitrile-styrene copolymer, polyacrylamide, and polyamide. . These can be used alone, as a mixture or as a copolymer, alone or in combination of two or more.

  Light having both functions as a charge transport material such as a polymer having a group derived from the charge transport material in a main chain or a side chain (for example, poly-N-vinylcarbazole, polyvinylanthracene, etc.) and a binder resin. A conductive resin may be used.

  The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent, and drying. The ratio between the charge transport material and the binder resin is preferably in the range of 2: 1 to 1: 2 (mass ratio).

  Solvents used in the charge transport layer coating solution include tetrahydrofuran, ethers such as dimethoxymethane, acetone, ketones such as methyl ethyl ketone, methyl acetate, esters such as ethyl acetate, aromatic hydrocarbons such as toluene and xylene, chlorobenzene, chloroform, A hydrocarbon substituted with a halogen atom such as carbon tetrachloride is used.

  When applying the coating solution for the charge transport layer, for example, an application method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, and a blade coating method can be used.

  The thickness of the charge transporting layer is preferably from 5 to 40 μm, more preferably from 5 to 30 μm, and even more preferably from 5 to 20 μm.

  Further, an antioxidant, an ultraviolet absorber, a plasticizer, a filler, and the like can be added to the charge transport layer as needed.

When the photosensitive layer is of the forward layer type, it is preferable to select a charge transporting substance or a binder resin having high transparency to the wavelength of the laser beam to be used.
When the photosensitive layer is a single layer type, the single layer type photosensitive layer is a single layer type photosensitive layer coating solution obtained by dispersing the charge generating substance and the charge transporting substance together with the binder resin and the solvent. It can be formed by coating and drying.

Further, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer from mechanical or chemical external force, and for the purpose of improving transferability and cleaning property.
The protective layer is a protective layer obtained by dissolving a resin such as polyvinyl butyral, polyester, polycarbonate, polyamide, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer and styrene-acrylonitrile copolymer with an organic solvent. It can be formed by applying a coating solution and drying.

  Further, in order to provide the protective layer with the charge transporting ability, the protective layer may be formed by curing a monomer material having a charge transporting ability or a polymer type charge transporting substance using various crosslinking reactions. . Examples of the curing reaction include radical polymerization, ionic polymerization, thermal polymerization, photopolymerization, radiation polymerization (electron beam polymerization), plasma CVD, and photoCVD.

Further, the protective layer may contain conductive particles, an ultraviolet absorber, an abrasion resistance improver, and the like. As the conductive particles, for example, metal oxides such as tin oxide particles are preferable. Preferred examples of the wear resistance improver include a fine powder of a fluorine-based resin, alumina, and silica.
Further, conductive particles, an ultraviolet absorber, an abrasion resistance improver, and the like can be added to the protective layer as needed. As the conductive particles, metal oxide particles such as tin oxide particles are preferable. As the wear resistance improver, fluorine atom-containing resin fine particles, alumina, silica and the like are preferable.

  The thickness of the protective layer is preferably from 0.5 to 20 μm, particularly preferably from 1 to 10 μm.

  In the present invention, the surface layer of the electrophotographic photoreceptor refers to a single-layer type photosensitive layer in the case of a layer configuration (single-layer type) as shown in FIG. 3A, and as shown in FIG. A simple layer configuration (forward layer type) indicates a charge transport layer, and a layer configuration (reverse layer type) as shown in FIG. 3C indicates a charge generation layer. When a protective layer is provided on these, the protective layer becomes a surface layer of the electrophotographic photosensitive member.

Next, the developer used in the present invention will be described.
The developer is roughly classified into a two-component developer composed of a toner and a carrier and a one-component developer composed of only a toner. Further, it can be roughly classified into a magnetic developer and a non-magnetic developer depending on the presence or absence of magnetism.

  The toner contained in the developer used in the present invention preferably has a specific particle size distribution. That is, if the toner having a particle size of 5 μm or less is less than 17% by number, the consumption may increase. Further, when the volume average particle diameter (Dv [μm]) is 8 μm or more and the weight average particle diameter (D4 [μm]) is 9 μm or more, the dot resolution of 100 μm or less tends to decrease, This tendency becomes more remarkable at a dot resolution of 20 to 40 μm. At this time, even if an attempt is made to develop with an unreasonable design under other developing conditions, it is difficult to obtain stable developability, for example, line thickening and toner scattering are likely to occur, and toner consumption is increased. On the other hand, if the number of toner particles having a particle size of 5 μm or less exceeds 90% by number, it is difficult to obtain stable developability, which may cause a problem such as a decrease in image density. In order to further improve the resolving power, the toner preferably satisfies 3.0 μm ≦ Dv ≦ 6.0 μm, 3.5 μm ≦ D4 <6.5 μm, and particularly, 3.2 μm ≦ Dv ≦ 5.8 μm. More preferably, 3.6 μm ≦ D4 ≦ 6.3 μm.

  As the binder resin used in the toner, for example, polystyrene, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene homopolymer or styrene copolymer such as styrene-butadiene copolymer, Examples include polyester resin, epoxy resin, and petroleum resin.

  It is preferable that wax be contained in the toner from the viewpoint of improving the releasability from the fixing member at the time of fixing and improving the fixing property. Examples of the wax include paraffin wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, polyolefin wax and its derivatives, carnauba wax and its derivatives, and the like. Examples of the derivative include an oxide, a block copolymer with a vinyl monomer, and a graft-modified product. In addition, long-chain alcohols, long-chain fatty acids, acid amide compounds, ester compounds, ketone compounds, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, mineral waxes, petrolactam, and the like can also be used.

  As the colorant used for the toner, various inorganic pigments, organic dyes, and organic pigments can be used.For example, carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodun lake, alizarin lake, bengara, Phthalocyanine blue, induslen blue and the like can be mentioned. The ratio of the colorant to the binder resin is preferably in the range of 0.5: 100 to 20: 100 (mass ratio).

Further, the toner may contain a magnetic material. Examples of the magnetic material include magnetic metal oxides containing elements such as iron, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. Among them, those mainly containing magnetic iron oxide such as triiron tetroxide and γ-iron oxide are preferable.
For the purpose of controlling the charge of the toner, the toner may contain a nigrosine dye, a quaternary ammonium salt, a metal complex of salicylic acid, a metal salt of salicylic acid, a metal complex of a salicylic acid derivative, salicylic acid, and acetylacetone.

  Further, the constitution of the toner is preferably such that inorganic fine powder is externally added to the toner particles. By externally adding inorganic fine powder to toner particles, development efficiency, reproducibility of an electrostatic latent image, and transfer efficiency are improved, and fog is reduced. Examples of the inorganic fine powder include fine powders such as colloidal silica, titanium oxide, iron oxide, aluminum oxide, magnesium oxide, calcium titanate, barium titanate, strontium titanate, magnesium titanate, cerium oxide, and zirconium oxide. Can be These may be used alone or in combination of one or more. Among these, fine powders of oxides or double oxides such as titania, alumina and silica are preferable.

The inorganic fine powder externally added to the toner particles is preferably subjected to a hydrophobic treatment. In particular, the inorganic fine powder is preferably surface-treated with a silane coupling agent or silicone oil. Examples of the hydrophobic treatment method include a method of treating with an organic metal compound such as a silane coupling agent that reacts with an inorganic fine powder or physically adsorbs on the inorganic fine powder, a titanium coupling agent, or a treatment with a silane coupling agent, or And a treatment with an organosilicon compound such as silicone oil at the same time as treatment with a silane coupling agent. The amount of the inorganic fine powder subjected to the hydrophobic treatment is preferably 0.01 to 8% by mass, more preferably 0.1 to 5% by mass, and more preferably 0 to 5% by mass, based on the toner particles. It is even more preferred that the content is 0.2 to 3% by mass.
The inorganic fine powder to be externally added to the toner particles is preferably specific surface area by nitrogen adsorption measured by BET method is ^{30 m} 2 / g or more, particularly in the range of 50 to 400 m ² / g More preferred.

  Other additives may be further added to the toner within a range that does not substantially adversely affect the toner. For example, lubricant powders such as polytetrafluoroethylene powder, zinc stearate powder, polyvinylidene fluoride powder, abrasives such as cerium oxide powder, silicon carbide powder, strontium titanate powder, titanium oxide powder, aluminum oxide powder, etc. Fluidity imparting agents, anti-caking agents, conductivity imparting agents such as carbon black powder, zinc oxide powder, and tin oxide powder, and developability improvers such as organic fine particles and inorganic fine particles having a polarity opposite to that of the toner. No.

  A known method can be used for producing the toner. For example, a binder resin, a wax, a metal salt or metal complex, a colorant, and, if necessary, a magnetic substance, a charge control agent, and other additives are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill. Melting and kneading using a hot kneader such as a heating roll, kneader, extruder, etc., and dispersing or dissolving the resins, dispersing or dissolving the metal salt or metal complex, colorant, magnetic material, etc., and solidifying by cooling Thereafter, the toner can be obtained by strictly performing pulverization and classification. In the classification step, it is preferable to use a multi-divider classifier in terms of production efficiency.

  Further, a method for producing a toner particle directly by suspending a polymerizable monomer, a colorant, and the like in an aqueous solvent, and dispersing polymer fine particles obtained by an emulsion polymerization method in an aqueous medium, In addition, a toner can be produced by a method of association fusion.

  In the case of a two-component developer, examples of the carrier having magnetism include powders of magnetic ferrite, magnetite, iron, and the like, and those coated with a resin such as an acrylic resin, a silicone resin, and a fluororesin.

  As the developing method of the electrophotographic apparatus of the present invention, a contact developing method such as a magnetic brush developing method using a two-component developer in which the developer and the surface of the electrophotographic photosensitive member come into contact with each other is preferable. preferable.

FIG. 4 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge.
In FIG. 4, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member which is rotated around an axis 2 at a predetermined peripheral speed in a direction indicated by an arrow. A fitting member (a driving member and / or a bearing member) for rotating and driving the electrophotographic photosensitive member 1 is fitted to both ends of the electrophotographic photosensitive member 1 (not shown). 1 and the fitting member constitute an electrophotographic photosensitive member unit.
The surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging unit (primary charging unit) 3 and then exposed to an exposure unit such as a slit exposure or a laser beam scanning exposure. (Not shown). Thus, an electrostatic latent image corresponding to a target image is sequentially formed on the surface of the electrophotographic photosensitive member 1.

The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed with a toner contained in a developer of a developing unit 5 to become a toner image (developed image, the same applies hereinafter). Next, the toner image formed and carried on the surface of the electrophotographic photosensitive member 1 is transferred from a transfer material supply unit (not shown) to the electrophotographic photosensitive member 1 by the transfer bias from the transfer unit (transfer roller) 6. (Contact portion), and is sequentially transferred to a transfer material (paper or the like) P taken out and fed in synchronization with the rotation of the electrophotographic photosensitive member 1.
The transfer material P to which the toner image has been transferred is separated from the surface of the electrophotographic photoreceptor 1, introduced into the fixing unit 8, and subjected to image fixing to be printed out as an image formed product (print, copy) outside the apparatus. Is done.

  After transfer of the toner image, the surface of the electrophotographic photoreceptor 1 is cleaned by a cleaning means (cleaning blade) 7 to remove the developer (toner) remaining after transfer, and further cleaned by a pre-exposure means (not shown). After being neutralized by pre-exposure light (not shown), it is repeatedly used for image formation. In addition, as shown in FIG. 4, when the charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

  Among the above-described components such as the electrophotographic photosensitive member unit, the charging unit 3, the developing unit 5, the transfer unit 6, and the cleaning unit 7, a plurality of components are housed in a container and integrally combined as a process cartridge. The process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In FIG. 4, the electrophotographic photoreceptor unit, the charging means 3, the developing means 5 and the cleaning means 7 are integrally supported to form a cartridge, and the electrophotographic apparatus is guided using a guide means 10 such as a rail of the main body of the electrophotographic apparatus. The process cartridge 9 is detachable from the main body.

  The amount of change in the distance (imaging distance) between the electrophotographic photosensitive member and the exposure means, which occurs when the accuracy of the electrophotographic photosensitive member unit is low, is large. It is difficult to accurately form a beam spot on the surface, and the amount of change in the gap or nip pressure between the electrophotographic photosensitive member and the developing member (such as a developing roller and a developing sleeve) during development becomes large. The technical problem that image roughness (unevenness of halftone images, roughness) is likely to occur due to unevenness is a technical problem of electrophotographic apparatuses in general. If the accuracy of the body unit is low, the amount of change in the gap or nip pressure between the electrophotographic photosensitive member and the developing member (such as a developing roller or a developing sleeve) during development becomes large. Therefore, color misregistration due to uneven development is likely to occur, and color misregistration is likely to occur due to insufficient positional accuracy between the electrophotographic photosensitive member and the transfer member or transfer paper during transfer. Therefore, the present invention exerts its effect more remarkably when the electrophotographic apparatus is a color electrophotographic apparatus.

  Hereinafter, as an example of a color electrophotographic apparatus, an intermediate transfer type color electrophotographic apparatus, an in-line type color electrophotographic apparatus, and a multiple transfer type color electrophotographic apparatus will be described. In the following description, an example of four colors (yellow, magenta, cyan, and black) has been given, but the “color” in the present invention is not limited to four colors (so-called full color), but is multicolor. That is, two or more colors.

FIG. 5 shows an example of a schematic configuration of an intermediate transfer type color electrophotographic apparatus. In the case of the intermediate transfer method, the transfer unit mainly includes a primary transfer member, an intermediate transfer member, and a secondary transfer member.
In FIG. 5, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member which is driven to rotate around an axis 2 in a direction of an arrow at a predetermined peripheral speed. A fitting member (a driving member and / or a bearing member) for rotating and driving the electrophotographic photosensitive member 1 is fitted to both ends of the electrophotographic photosensitive member 1 (not shown). 1 and the fitting member constitute an electrophotographic photosensitive member unit.

  The surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging unit (primary charging unit) 3 and then exposed to an exposure unit such as a slit exposure or a laser beam scanning exposure. (Not shown). The exposure light at this time is exposure light corresponding to a first color component image (for example, a yellow component image) of a target color image. Thus, a first color component electrostatic latent image (yellow component electrostatic latent image) corresponding to the first color component image of the target color image is sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The intermediate transfer body (intermediate transfer belt) 11 stretched by the stretching roller 12 and the secondary transfer opposing roller 13 has a peripheral speed substantially equal to that of the electrophotographic photosensitive member 1 in the direction of the arrow (for example, the peripheral speed of the electrophotographic photosensitive member 1). 97 to 103%).

The first color component electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed by a first color toner (yellow toner) included in a developer of a first color developing unit (yellow developing unit) 5Y. As a result, a first color toner image (yellow toner image) is formed. Next, the first color toner image formed and carried on the surface of the electrophotographic photosensitive member 1 is transferred between the electrophotographic photosensitive member 1 and the primary transfer member (primary transfer roller) 6p by the primary transfer bias from the primary transfer member 6p. The primary transfer is sequentially performed on the surface of the intermediate transfer body 11 passing through the gap.
The surface of the electrophotographic photosensitive member 1 after the transfer of the first color toner image is cleaned by the cleaning means 7 to remove the developer (toner) remaining after the primary transfer, and then used for forming the next color image. You.

  The second color toner image (magenta toner image), the third color toner image (cyan toner image), and the fourth color toner image (black toner image) are also formed on the surface of the electrophotographic photosensitive member 1 in the same manner as the first color toner image. And is sequentially transferred to the surface of the intermediate transfer body 11. Thus, a composite toner image corresponding to the target color image is formed on the surface of the intermediate transfer member 11. During the primary transfer of the first to fourth colors, the secondary transfer member (secondary transfer roller) 6s and the charge applying means (charge applying roller) 7r are separated from the surface of the intermediate transfer body 11.

The composite toner image formed on the surface of the intermediate transfer member 11 is transferred from the transfer material supply means (not shown) to the secondary transfer opposing roller 13 and the intermediate transfer member 11 by the secondary transfer bias from the secondary transfer member 6s. Secondary transfer is sequentially performed on a transfer material (paper or the like) P taken out and fed between the next transfer member 6 s (contact portion) in synchronization with the rotation of the intermediate transfer body 11.
The transfer material P to which the composite toner image has been transferred is separated from the surface of the intermediate transfer body 11, introduced into the fixing means 8, and subjected to image fixing, thereby being printed out of the apparatus as a color image formed product (print, copy). Be out.

  The charge applying means 7r is brought into contact with the surface of the intermediate transfer body 11 after the transfer of the synthetic toner image. The charge applying unit 7r applies a charge of a polarity opposite to that at the time of the primary transfer to the secondary transfer residual developer (toner) on the surface of the intermediate transfer body 11. The developer (toner) remaining after the secondary transfer to which a charge having the opposite polarity to that at the time of the primary transfer is applied is provided at the contact portion between the electrophotographic photosensitive member 1 and the intermediate transfer member 11 and in the vicinity thereof. It is electrostatically transferred to the surface. In this way, the surface of the intermediate transfer body 11 after the transfer of the synthetic toner image is cleaned to remove the transfer residual developer (toner). The secondary transfer residual developer (toner) transferred to the surface of the electrophotographic photosensitive member 1 is removed by the cleaning unit 7 together with the primary transfer residual developer (toner) of the electrophotographic photosensitive member 1 surface. The transfer of the developer (toner) remaining after the secondary transfer from the intermediate transfer body 11 to the electrophotographic photoreceptor 1 can be performed simultaneously with the primary transfer, so that the throughput does not decrease.

  Further, the surface of the electrophotographic photoreceptor 1 from which the developer (toner) remaining after transfer has been removed by the cleaning unit 7 may be subjected to static elimination processing by pre-exposure light from the pre-exposure unit, as shown in FIG. When the charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

FIG. 6 shows an example of a schematic configuration of an in-line type color electrophotographic apparatus. In the case of the in-line method, the transfer means mainly includes a transfer material transporting member and a transfer member.
In FIG. 6, reference numerals 1Y, 1M, 1C, and 1K denote cylindrical electrophotographic photoconductors (electrophotographic photoconductors for first to fourth colors), each of which is centered on the axis 2Y, 2M, 2C, or 2K in the direction of an arrow. At a predetermined peripheral speed. At both ends of the electrophotographic photosensitive members 1Y, 1M, 1C, and 1K, fitting members (driving members and / or bearing members) for rotating and driving the electrophotographic photosensitive members 1Y, 1M, 1C, and 1K, respectively, are provided. The electrophotographic photoreceptor 1 </ b> Y and the fitting member constitute a first color electrophotographic photoreceptor unit, and the electrophotographic photoreceptor 1 </ b> M and the fitting member form a second color electronic device. The electrophotographic photoreceptor unit is constituted by the electrophotographic photoreceptor 1C and the fitting member, and the electrophotographic photoreceptor unit for the third color is constituted by the electrophotographic photoreceptor 1K and the fitting member. It constitutes a photoreceptor unit.

  The surface of the electrophotographic photoreceptor 1Y for the first color that is driven to rotate is uniformly charged to a predetermined positive or negative potential by a first-color charging unit (first-color primary charging unit) 3Y. It receives exposure light (image exposure light) 4Y output from exposure means (not shown) such as exposure or laser beam scanning exposure. The exposure light 4Y is exposure light corresponding to a first color component image (for example, a yellow component image) of a target color image. In this way, a first color component electrostatic latent image (yellow component electrostatic latent image) corresponding to the first color component image of the target color image is sequentially formed on the surface of the first color electrophotographic photosensitive member 1Y.

  The transfer material transporting member (transfer material transport belt) 14 stretched by the stretching roller 12 has a peripheral speed substantially equal to that of the electrophotographic photoreceptors 1Y, 1M, 1C, and 1K for the first to fourth colors in the direction of the arrow. For example, it is driven to rotate at 97 to 103% of the peripheral speed of the electrophotographic photosensitive members 1Y, 1M, 1C, and 1K for the first to fourth colors. Further, the transfer material (paper or the like) P fed from the transfer material supply means (not shown) is electrostatically carried (adsorbed) by the transfer material transport member 14, and the first to fourth color electrophotographs. It is sequentially conveyed between the photoconductors 1Y, 1M, 1C, and 1K and the transfer material conveying member (contact portion).

  The first color component electrostatic latent image formed on the surface of the first color electrophotographic photoreceptor 1Y is developed by the first color toner contained in the developer of the first color developing means 5Y to form the first color toner. Image (yellow toner image). Next, the first color toner image formed and carried on the surface of the first color electrophotographic photoreceptor 1Y is transferred to the first color by a transfer bias from a first color transfer member (first color transfer roller) 6Y. Is sequentially transferred to the transfer material P carried by the transfer material transporting member 14 passing between the electrophotographic photosensitive member 1Y for use and the transfer member 6Y for the first color.

  The surface of the electrophotographic photosensitive member 1Y for the first color after the transfer of the first color toner image is subjected to removal of the developer (toner) remaining after transfer by the first color cleaning means (first color cleaning blade) 7Y. After being cleaned, it is repeatedly used for forming a first color toner image.

  The first color electrophotographic photoreceptor 1Y, the first color charging unit 3Y, the first color exposing unit, the first color developing unit 5Y, and the first color transfer member 6Y are collectively assembled into a first color image forming unit. Called.

  A second-color electrophotographic photosensitive member 1M, a second-color charging unit 3M, a second-color exposure unit, a second-color developing unit 5M, and a second-color image forming unit including a second-color transfer member 6M; A third-color electrophotographic photosensitive member 1C, a third-color charging unit 3C, a third-color exposure unit, a third-color developing unit 5C, and a third-color image forming unit including a third-color transfer member 6C; A fourth-color electrophotographic photosensitive member 1K, a fourth-color charging unit 3K, a fourth-color exposure unit, a fourth-color developing unit 5K, and a fourth-color image forming unit including a fourth-color transfer member 6K. The operation is the same as the operation of the first color image forming unit, and the second color toner image (magenta toner image) is transferred onto the transfer material P carried by the transfer material transporting member 14 and onto which the first color toner image has been transferred. The third color toner image (cyan toner image) and the fourth color toner image (black toner image) are sequentially transferred. In this way, a synthetic toner image corresponding to the target color image is formed on the transfer material P carried on the transfer material transport member 14.

  The transfer material P on which the synthetic toner image has been formed is separated from the surface of the transfer material transport member 14, introduced into the fixing means 8 and subjected to image fixing to be printed out of the apparatus as a color image formed product (print, copy). Be out.

  Further, the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K after removing the transfer residual developer (toner) by the first to fourth color cleaning units 7Y, 7M, 7C, and 7K. May be subjected to static elimination processing by pre-exposure light from the pre-exposure means, but as shown in FIG. 6, the first to fourth color charging means 3Y, 3M, 3C, 3K use charging rollers and the like. When the contact charging means is used, pre-exposure is not always necessary.

  In FIG. 6, reference numeral 15 denotes an attraction roller for adsorbing the transfer material to the transfer material transport member, and 16 denotes a separation charger for separating the transfer material from the transfer material transport member.

FIG. 7 shows an example of a schematic configuration of a multiple transfer type color electrophotographic apparatus. In the case of the multiple transfer method, the transfer means mainly includes a transfer material carrying member and a transfer charger.
In FIG. 7, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member which is rotated around an axis 2 at a predetermined peripheral speed in a direction indicated by an arrow. A fitting member (a driving member and / or a bearing member) for rotating and driving the electrophotographic photosensitive member 1 is fitted to both ends of the electrophotographic photosensitive member 1 (not shown). 1 and the fitting member constitute an electrophotographic photosensitive member unit.

  The surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging unit (primary charging unit) 3 and then exposed to an exposure unit such as a slit exposure or a laser beam scanning exposure. (Not shown). The exposure light at this time is exposure light corresponding to a first color component image (for example, a yellow component image) of a target color image. Thus, a first color component electrostatic latent image (yellow component electrostatic latent image) corresponding to the first color component image of the target color image is sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The transfer material carrying member (transfer drum) 17 is driven to rotate in the direction of the arrow at substantially the same peripheral speed as the electrophotographic photosensitive member 1 (for example, 97 to 103% with respect to the peripheral speed of the electrophotographic photosensitive member 1). Further, the transfer material (paper or the like) P fed from a transfer material supply unit (not shown) is electrostatically held (adsorbed) on the transfer material holding member 17, and the electrophotographic photosensitive member 1 and the transfer material holding member (Contact portion).

  The first color component electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed by a first color toner (yellow toner) included in a developer of a first color developing unit (yellow developing unit) 5Y. As a result, a first color toner image (yellow toner image) is formed. Next, the transfer material passing between the electrophotographic photoreceptor 1 and the transfer charger 6co is transferred by the transfer bias from the transfer charger 6co to the first color toner image formed and carried on the surface of the electrophotographic photoreceptor 1. The image is transferred onto the transfer material P carried on the carrying member 17.

  After the transfer of the first color toner image, the surface of the electrophotographic photoreceptor 1 is cleaned by the cleaning unit 7 to remove the untransferred developer (toner), and then used for forming the next color image. .

  The second color toner image (magenta toner image), the third color toner image (cyan toner image), and the fourth color toner image (black toner image) are also formed on the surface of the electrophotographic photosensitive member 1 in the same manner as the first color toner image. The second color toner image (magenta toner image), the third color toner image (cyan toner image), the third color toner image (cyan toner image) are formed on the transfer material P, which is formed on the transfer material holding member 17 and transferred with the first color toner image. The four-color toner image (black toner image) is sequentially transferred. Thus, a synthetic toner image corresponding to the target color image is formed on the transfer material P carried on the transfer material carrying member 17.

  The transfer material P on which the synthetic toner image is formed is separated from the surface of the transfer material supporting member 17 and is introduced into the fixing means 8 to be subjected to image fixing to be printed out of the apparatus as a color image formed product (print, copy). Be out.

  Further, the surface of the electrophotographic photosensitive member 1 from which the transfer residual developer (toner) has been removed by the cleaning unit 7 may be subjected to static elimination processing by pre-exposure light from the pre-exposure unit, as shown in FIG. When the charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

  In FIG. 7, reference numeral 15a denotes an attraction roller for adsorbing the transfer material to the transfer material carrying member, 15b denotes an attraction charger for attracting the transfer material to the transfer material carrying member, and 16 denotes a transfer material carrying member. This is a separation charger for separating a transfer material from a member.

  Also, in the color electrophotographic apparatus having the configuration shown in FIGS. 5 to 7, similarly to the electrophotographic apparatus having the configuration shown in FIG. 4, the electrophotographic photosensitive member unit, the charging unit, the developing unit, the transfer unit, the cleaning unit, and the like are provided. Of the components, a plurality of components may be housed in a container and integrally connected as a process cartridge, and the process cartridge may be configured to be detachable from an electrophotographic apparatus body such as a copying machine or a laser beam printer. Good.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “parts” means “parts by mass”.

(Example 1)
FIG. 8 shows a schematic configuration of a full-color electrophotographic apparatus used in this embodiment.
The full-color electrophotographic apparatus having the configuration shown in FIG. 8 has a digital full-color image reader unit at the top and a digital full-color image printer unit at the bottom.
In the reader unit, the original 830 is placed on an original platen glass 831, and is exposed and scanned by an exposure lamp 832, so that a reflected light image from the original 830 is condensed on a full-color sensor 834 by a lens 833, and a full-color color separation image signal is output. Get. The full-color color-separated image signal is processed by a video processing unit (not shown) through an amplifier circuit (not shown), and is sent to a printer unit.

  In the printer section, reference numeral 801 denotes an electrophotographic photosensitive member (an electrophotographic photosensitive member described later), which is rotatably supported in the direction of the arrow. Around the electrophotographic photosensitive member 801, a pre-exposure lamp 811 (six fuse lamps in series × 2 in parallel, 550 nm or less is cut by a filter, pre-exposure means) and a corona charger 802 (charging means) A laser exposure optical system 803 (equipped with a GaN-based chip having an oscillation wavelength of 405 nm and an output of 5 mW manufactured by Nichia Corporation), a potential sensor 812, a yellow developing device 804y, and cyan 804c, a magenta developing device 804m, a black developing device 804Bk (developing device), a light amount detector 813 on the surface of the electrophotographic photosensitive member, a transfer device, and a cleaning device 806 (cleaning device). ing. Each of the developing devices 804y, 804c, 804m, and 804Bk has a developing sleeve.

In the laser exposure optical system 803, an image signal from the reader unit is converted into an optical signal for image scan exposure by a laser output unit (not shown), and the converted laser beam is reflected by the polygon mirror 803a, and the lens 803b The light is projected on the surface of the electrophotographic photosensitive member 801 through the mirror 803c. The writing pitch was set to 600 dpi, and the beam spot diameter was set to 32 μm (the main scanning direction spot diameter was 28 μm, and the sub scanning direction spot diameter was 36 μm).
At the time of image formation in the printer unit, the electrophotographic photosensitive member 801 is rotated in the direction of the arrow, and the electrophotographic photosensitive member 801 after being neutralized by the pre-exposure lamp 811 is uniformly and negatively charged by a corona charger 802, so that each decomposition is performed. A light image 800E is irradiated for each color to form an electrostatic latent image on the surface of the electrophotographic photosensitive member 801.

  Next, a predetermined developing device is operated to develop the electrostatic latent image on the surface of the electrophotographic photosensitive member 801 to form a developed image using a two-component developer (using a negative toner) on the surface of the electrophotographic photosensitive member 801. I do. The developing device is configured to selectively approach the electrophotographic photosensitive member 801 in accordance with each separation color by the operation of the eccentric cams 824y, 824c, 824m, and 824Bk.

Further, the developed image on the surface of the electrophotographic photosensitive member 801 is transferred from a transfer material cassette 807 containing paper (transfer material) to a position facing the electrophotographic photosensitive member 801 via a transport system and a transfer unit. Transfer to
The transfer unit includes a transfer drum 805a, a transfer charger 805b, an attraction roller 805g opposed to an attraction charger 805c for electrostatically attracting paper, an inner charger 805d, and an outer charger 805e. The transfer drum 805a that is rotatably supported has a transfer material carrying sheet 805f that is integrally formed in a cylindrical shape in a peripheral opening area. As the transfer material carrying sheet 805f, a polycarbonate film as a dielectric sheet is used.

As the transfer drum 805a is rotated, the developed image on the surface of the electrophotographic photoreceptor 801 is transferred by the transfer charger 805b to the paper carried on the transfer material carrying sheet 805f of the transfer drum 805a.
In this manner, a desired number of color images are transferred to the paper carried on the transfer material carrying sheet 805f of the transfer drum 805a, and a full-color image is formed.
In the case of forming a full-color image, when the transfer of the developed images of four colors is completed in this way, the paper is separated from the transfer drum 805a by the action of the separation claw 808a, the separation push-up roller 808b, and the separation charger 805h, and the heat roller is fixed. The paper is discharged to a tray 810 via a container 809.

On the other hand, the electrophotographic photoreceptor 801 after the transfer is cleaned by the cleaning device 806 to remove the developer remaining on the surface, and then subjected to the image forming process again.
When an image is formed on both sides of the paper, the conveyance path switching guide 819 is driven immediately after the heat roller fixing unit 809 is discharged, and the conveyance path switching guide 819 is guided to the reversal path 821a via the conveyance vertical path 820. By the reverse rotation of 821 b, the sheet is retreated in a direction opposite to the direction in which the sheet is fed, with the rear end of the sheet being fed, and stored in the intermediate tray 822. Thereafter, an image is formed on the other surface again by the above-described image forming step.

  Further, in order to prevent scattering of powder on the transfer material carrying sheet 805f of the transfer drum 805a and adhesion of oil on paper, a backup facing the fur brush 814 via the fur brush 814 and the transfer material carrying sheet 805f. Cleaning is performed by the action of a backup brush 817 facing the oil removing roller 816 via the brush 815, the oil removing roller 816, and the transfer material carrying sheet 805f. Such cleaning is performed before or after image formation, and at any time when a paper jam occurs.

  The gap between the transfer material carrying sheet 805f and the electrophotographic photosensitive member 801 can be set arbitrarily by operating the eccentric cam 825 at a desired timing and operating the cam follower 805i integrated with the transfer drum 805a. It has a configuration. For example, during standby or when the power is off, the distance between the transfer drum 805a and the electrophotographic photosensitive member 801 is increased.

The electrophotographic photosensitive member used in this example was manufactured according to the following procedure.
A cutting aluminum cylinder (manufactured by Furukawa Electric Co., Ltd.) having a cylindrical run-out of 10 μm, a length of 360 mm, a diameter of 180 mm, and a 10-point average roughness Rzjis of 0.4 μm was used as a support.
In the present invention, the measurement of the 10-point average roughness Rzjis is based on JIS B0601 (2001) using a surf coder SE-3500 (manufactured by Kosaka Laboratory Co., Ltd.) with a cutoff of 0.8 mm. The length was set to 8 mm.

Next, 50 parts of conductive titanium oxide particles coated with tin oxide containing 10% antimony oxide, 25 parts of phenolic resin, 20 parts of methyl cellosolve, 5 parts of methanol, and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer) (Polymer, number average molecular weight: 3000) 0.002 parts was dispersed in a sand mill using a glass beam having a diameter of 1 mm for 2 hours to prepare a conductive layer coating solution.
This conductive layer coating solution was applied onto the support by dip coating, and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

Next, 30 parts of a methoxymethylated nylon resin (number average molecular weight: 32000) and 10 parts of an alcohol-soluble copolymerized nylon resin (number average molecular weight: 29000) are dissolved in a mixed solvent of 260 parts of methanol / 40 parts of butanol. Thus, a coating solution for an intermediate layer was prepared.
The coating liquid for an intermediate layer was applied onto the conductive layer by dip coating and dried to form an intermediate layer having a thickness of 1 μm.

Next, the Bragg angles (2θ ± 0.2 °) in the CuKα characteristic X-ray diffraction were changed to 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 °. A glass bead having a diameter of 1 mm was prepared by using 10 parts of a crystalline form of hydroxygallium phthalocyanine having a strong peak, 5 parts of polyvinyl butyral (trade name: Esrec BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 250 parts of cyclohexanone. The mixture was dispersed in a sand mill for 3 hours, and then 250 parts of ethyl acetate was added to prepare a charge generating layer coating solution.
This charge generation layer coating solution was applied onto the intermediate layer by dip coating and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.25 μm.

および、ポリカーボネート樹脂（商品名：ユーピロンＺ−４００、三菱瓦斯化学（株）製）１０部をモノクロルベンゼン７０部に溶解して、電荷輸送層用塗布液を調製した。 Next, 7 parts of a charge transport material (A) having a structure represented by the following formula,

In addition, 10 parts of a polycarbonate resin (trade name: Iupilon Z-400, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in 70 parts of monochlorobenzene to prepare a coating solution for a charge transport layer.

This coating solution for a charge transport layer was applied onto the charge generation layer by dip coating and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 13 μm.
Thus, a cylindrical electrophotographic photosensitive member having the charge transport layer as the surface layer was produced.

  Next, flanges for rotational driving were fitted to both ends of the produced electrophotographic photosensitive member to obtain an electrophotographic photosensitive member unit. The cylindrical deflection (De) of the electrophotographic photosensitive member unit was 15 μm.

  The electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus having the structure shown in FIG. 8 to output a full-color image, and the output full-color image output was visually evaluated. The dark section potential (charging potential) was set to -700 V, the bright section potential was set to -200 V, and the developing bias was set to -550 V.

Table 1 shows the evaluation results. In Table 1, the evaluation criteria for roughness (unevenness of halftone images, roughness) and color shift are AA: no A: almost no B: some inconspicuous C: some D: noticeable E: very noticeable is there.

(Example 2)
In Example 1, except that the support was changed to a cut aluminum cylinder (manufactured by Furukawa Electric Co., Ltd.) having a cylindrical deflection: 19 μm, a length: 360 mm, a diameter: 180 mm, and a 10-point average roughness Rzjis: 0.5 μm. In the same manner as in Example 1, an electrophotographic photosensitive member was manufactured, and flanges were fitted to both ends of the manufactured electrophotographic photosensitive member for rotational driving, thereby forming an electrophotographic photosensitive member unit. The cylindrical runout (De) of this electrophotographic photosensitive member unit was 27 μm.
This electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 as in Example 1, and a full-color image output was performed. The output full-color image output was visually evaluated. Table 1 shows the evaluation results.

(Example 3)
In Example 1, except that the support was changed to a cut aluminum cylinder (manufactured by Furukawa Electric Co., Ltd.) having a cylindrical deflection: 31 μm, a length: 360 mm, a diameter: 180 mm, and a 10-point average roughness Rzjis: 0.5 μm. Was formed up to the charge generation layer of the electrophotographic photosensitive member in the same manner as in Example 1.

下記式で示される構造を有する電荷輸送物質（Ｂ）１部、

および、ポリカーボネート樹脂（商品名：ユーピロンＺ−２００、三菱瓦斯化学（株）製）１０部をモノクロルベンゼン６０部に溶解して、電荷輸送層（第１電荷輸送層）用塗布液を調製した。 Next, 6 parts of a charge transport material (A) having a structure represented by the following formula,

1 part of a charge transport material (B) having a structure represented by the following formula,

Then, 10 parts of a polycarbonate resin (trade name: Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in 60 parts of monochlorobenzene to prepare a coating solution for a charge transport layer (first charge transport layer).

  This coating solution for the charge transport layer (first charge transport layer) is dip-coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer (first charge transport layer) having a thickness of 10 μm. Formed.

を溶解して、保護層（第２電荷輸送層）用塗布液を調製した。 Next, 3 parts of polytetrafluoroethylene resin particles (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.), 6 parts of polycarbonate resin (trade name: Iupilon Z-800), comb-type fluorine-based graft polymer ( 0.24 parts of GF300 (manufactured by Toa Gosei Chemical Industry Co., Ltd.), 120 parts of monochlorobenzene, and 80 parts of methylal were dispersed and mixed by an ultra-high pressure disperser. And 3 parts of a charge transport material (A) having a structure represented by the following formula:

Was dissolved to prepare a coating solution for a protective layer (second charge transport layer).

This protective layer (second charge transport layer) coating solution is spray-coated on the charge transport layer (first charge transport layer), dried at 80 ° C. for 10 minutes, and then at 120 ° C. for 50 minutes, and thereafter, an abrasive sheet (Lapping tape, abrasive particles: alumina, abrasive particle diameter: 3000, manufactured by Fuji Photo Film Co., Ltd.), the surface was polished for 1 minute, the film thickness was 3 μm, and the 10-point average roughness Rzjis was 0.7 μm. Was formed (second charge transport layer).
Thus, a cylindrical electrophotographic photosensitive member having a protective layer (second charge transport layer) as a surface layer was produced.

Next, flanges for rotational driving were fitted to both ends of the produced electrophotographic photosensitive member to obtain an electrophotographic photosensitive member unit. The cylindrical deflection (De) of the electrophotographic photosensitive member unit was 40 μm.
This electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 as in Example 1, and a full-color image output was performed. The output full-color image output was visually evaluated. Table 1 shows the evaluation results.

に変更した以外は、実施例２と同様にして電子写真感光体を作製し、作製した電子写真感光体の両端に回転駆動用にフランジを嵌合して、電子写真感光体ユニットとした。この電子写真感光体ユニットの円筒振れ（Ｄｅ）は２８μｍであった。 (Example 4)
In Example 2, the hydroxygallium phthalocyanine used for the charge generation layer was replaced with an azo pigment having a structure represented by the following formula:

An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the electrophotographic photosensitive member was changed to the above, and flanges were fitted to both ends of the produced electrophotographic photosensitive member for rotational driving, thereby forming an electrophotographic photosensitive member unit. The cylindrical deflection (De) of this electrophotographic photosensitive member unit was 28 μm.

  This electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 as in Example 2, and a full-color image output was performed. The output full-color image output was visually evaluated. Table 1 shows the evaluation results.

(Comparative Example 1)
In Example 1, except that the support was changed to a cut aluminum cylinder (manufactured by Furukawa Electric Co., Ltd.) having a cylindrical deflection: 50 μm, a length: 360 mm, a diameter: 180 mm, and a 10-point average roughness Rzjis: 0.6 μm. In the same manner as in Example 1, an electrophotographic photosensitive member was manufactured, and flanges were fitted to both ends of the manufactured electrophotographic photosensitive member for rotational driving, thereby forming an electrophotographic photosensitive member unit. The cylindrical deflection (De) of the electrophotographic photosensitive member unit was 60 μm.
This electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 as in Example 1, and a full-color image output was performed. The output full-color image output was visually evaluated. Table 1 shows the evaluation results.

(Comparative Example 2)
In Example 1, except that the support was changed to a cut aluminum cylinder (manufactured by Furukawa Electric Co., Ltd.) having a cylindrical deflection: 70 μm, a length: 360 mm, a diameter: 180 mm, and a 10-point average roughness Rzjis: 0.2 μm. In the same manner as in Example 1, an electrophotographic photosensitive member was manufactured, and flanges were fitted to both ends of the manufactured electrophotographic photosensitive member for rotational driving, thereby forming an electrophotographic photosensitive member unit. The cylindrical deflection (De) of the electrophotographic photosensitive member unit was 90 μm.
This electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 as in Example 1, and a full-color image output was performed. The output full-color image output was visually evaluated. Table 1 shows the evaluation results.

(Comparative Example 3)
An electrophotographic photosensitive member and an electrophotographic photosensitive member unit were the same as in Example 3 except that the beam spot diameter was set to 25 μm (the spot diameter in the main scanning direction was 22 μm and the spot diameter in the sub-scanning direction was 28 μm). Was prepared and evaluated. Table 1 shows the evaluation results.

(Example 5)
In Comparative Example 3, the evaluation was performed in the same manner as in Comparative Example 3, except that the electrophotographic photosensitive member and the electrophotographic photosensitive member unit were changed to the electrophotographic photosensitive member and the electrophotographic photosensitive member unit manufactured in the same manner as in Example 2. Table 1 shows the evaluation results.

(Comparative Example 4)
In Example 3, the GaN-based chip mounted on the laser exposure optical system 803 of the full-color electrophotographic apparatus used for the evaluation was changed to an AlGaInP-based chip (oscillation wavelength: 670 nm), and the beam spot diameter was 60 μm (main scanning). An electrophotographic photosensitive member and an electrophotographic photosensitive member unit were prepared and evaluated in the same manner as in Example 3 except that the beam spot diameter in the directional direction was set to 55 μm and the spot diameter in the sub-scanning direction was set to 65 μm. Table 1 shows the evaluation results.

(Example 6)
In Example 1, except that the support was changed to a drawn aluminum cylinder (manufactured by Showa Aluminum Co., Ltd.) having a cylindrical runout of 15 μm, a length of 360 mm, a diameter of 30 mm, and a 10-point average roughness Rzjis of 0.8 μm. Then, an electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and flanges were fitted to both ends of the manufactured electrophotographic photosensitive member for rotational driving to obtain an electrophotographic photosensitive member unit. The cylindrical deflection (De) of this electrophotographic photosensitive member unit was 21 μm.

This electrophotographic photoreceptor unit was mounted on a full-color electrophotographic apparatus (in-line system) having the configuration shown in FIG. 9 to output a full-color image, and the output full-color image output was visually evaluated as in Example 1. Table 1 shows the evaluation results.
The laser exposure optical system of the full-color electrophotographic apparatus having the configuration shown in FIG. 9 has a GaN-based chip manufactured by Nichia Corporation having an oscillation wavelength of 405 nm and an output of 5 mW. The writing pitch was 400 dpi, and the beam spot diameter was 31 μm (spot diameter in the main scanning direction: 28 μm, spot diameter in the sub-scanning direction: 34 μm).

  9, reference numeral 901 denotes an electrophotographic photosensitive member; 902, a corona charger; 903a, a polygon mirror; 903c, a mirror; 904c, 904y, 904m, and 904Bk, developing devices; Is a transfer material transport belt, 950 is a transfer charger, 907 is a transfer material cassette, and 909 is a fixing device.

ポリテトラフルオロエチレン樹脂粒子（商品名：ルブロンＬ−２、ダイキン工業（株）製）４部、および、ｎ−プロピルアルコール６０部を、超高圧分散機で分散して、保護層（第２電荷輸送層）用塗布液を調製した。 (Example 7)
A charge transport layer (first charge transport layer) was formed in the same manner as in Example 6, except that the thickness of the charge transport layer (first charge transport layer) was changed to 10 μm.
Next, 36 parts of a charge transport material (C) having a structure represented by the following formula,

4 parts of polytetrafluoroethylene resin particles (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) and 60 parts of n-propyl alcohol are dispersed by an ultra-high pressure disperser, and the protective layer (second charge) is dispersed. A coating solution for the transport layer was prepared.

This coating solution for the protective layer (second charge transport layer) is dip-coated on the charge transport layer (first charge transport layer), and then the electron beam is applied in nitrogen under the conditions of an acceleration voltage of 150 kV and a dose of 1.5 Mrad. Then, a heat treatment is performed for 3 minutes under the condition that the temperature of the electrophotographic photoreceptor becomes 120 ° C. (at this time, the oxygen concentration is 20 ppm). After 1 hour, post-treatment was performed to form a protective layer (second charge transport layer) having a thickness of 5 μm.
Thus, a cylindrical electrophotographic photosensitive member having a protective layer (second charge transport layer) as a surface layer was produced.

Next, flanges for rotational driving were fitted to both ends of the produced electrophotographic photosensitive member to obtain an electrophotographic photosensitive member unit. The cylindrical deflection (De) of this electrophotographic photosensitive member unit was 26 μm.
This electrophotographic photosensitive member unit was evaluated in the same manner as in Example 6. Table 1 shows the evaluation results.

(Comparative Example 5)
In Example 6, the GaN-based chip mounted on the laser exposure optical system of the full-color electrophotographic apparatus used for the evaluation was changed to a GaAlAs-based chip (oscillation wavelength: 780 nm), and the beam spot diameter was 56 μm (in the main scanning direction). An electrophotographic photosensitive member and an electrophotographic photosensitive member unit were prepared and evaluated in the same manner as in Example 6, except that the spot diameter was set to 48 μm and the spot diameter in the sub-scanning direction was set to 64 μm. Table 1 shows the evaluation results.

(Comparative Example 6)
In Comparative Example 5, an electrophotographic photosensitive member and an electrophotographic unit were produced and evaluated in the same manner as in Comparative Example 5, except that the writing pitch of the full-color electrophotographic apparatus used for evaluation was set to 600 dpi. Table 1 shows the evaluation results.

  As described above, according to the present invention, it is possible to output an ultra-high-resolution and ultra-high-quality image in an electrophotographic apparatus in which the spot diameter of the beam spot is reduced using a laser having an oscillation wavelength in the range of 380 to 450 nm. An electrophotographic apparatus can be provided, and a process cartridge and an electrophotographic photoreceptor unit used in the electrophotographic apparatus can be provided.

It is a figure for explaining the measuring method of the spot diameter (Di [μm]) of the beam spot. It is a figure showing the schematic structure of a cylindrical shake measuring device. FIG. 3 is a diagram illustrating a configuration of a photosensitive layer. FIG. 2 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge. FIG. 1 is a diagram illustrating an example of a schematic configuration of a color electrophotographic apparatus of an intermediate transfer system. FIG. 1 is a diagram illustrating an example of a schematic configuration of an in-line type color electrophotographic apparatus. FIG. 1 is a diagram illustrating an example of a schematic configuration of a multi-transfer type color electrophotographic apparatus. FIG. 4 is a diagram illustrating a schematic configuration of a full-color electrophotographic apparatus used in Examples 1 to 5. FIG. 9 is a diagram illustrating a schematic configuration of a full-color electrophotographic apparatus used in Examples 6 and 7.

Explanation of reference numerals

A Peak intensity D1 Spot diameter in the main scanning direction of the beam spot D2 Spot diameter in the sub-scanning direction of the beam spot 201 Electrophotographic photoreceptor unit 202 Reference gauge 203 Laser beam 204 Base 205 Driving side receiving jig 206 Subordinate side receiving jig 207 Slide base 208 Rotating device 301 Support 302 Photosensitive layer 303 Charge generation layer 304 Charge transport layer 1 Electrophotographic photoreceptor 2 Shaft 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 8 Fixing means 9 Process cartridge 10 Guide means P Transfer Material 5Y Developing means for the first color 5M Developing means for the second color 5C Developing means for the third color 5K Developing means for the fourth color 6p Primary transfer member 6s Secondary transfer member 7r Charge applying means 11 Intermediate transfer body 12 Stretch roller 13 Secondary transfer opposed roller 1Y Electrophotographic photoreceptor for first color 1M Second color Electrophotographic photosensitive member 1C Electrophotographic photosensitive member for third color 1K Electrophotographic photosensitive member for fourth color 2Y Axis 2M Axis 2C Axis 2K Axis 3Y Charging means for first color 3M Charging means for second color 3C Charging for third color Means 3K Fourth-color charging means 4Y Exposure light 4M Exposure light 4C Exposure light 4K Exposure light 5Y First-color development means 5M Second-color development means 5C Third-color development means 5K Fourth-color development means 6Y One-color transfer member 6M Second-color transfer member 6C Third-color transfer member 6K Fourth-color transfer member 7Y First-color cleaning means 7M Second-color cleaning means 7C Third-color cleaning means 7K Fourth Color cleaning means 14 Transfer material transporting member 15 Suction roller 16 Separation charger 6co Transfer charger 15a Suction roller 15b Suction charger 17 Transfer material holding member 800E Optical image 801 Electrophotographic photosensitive member 802 Corona Charger 803 Laser exposure optical system 803a Polygon mirror 803b Lens 803c Mirror 804y Yellow developer 804c Cyan developer 804m Magenta developer 804Bk Black developer 805a Transfer drum 805b Transfer charger 805c Adsorption charger 805d Inner charger 805e Outer charger 805f Transfer material carrying sheet 805g Suction roller 805h Separation charger 805i Cam follower 806 Cleaning device 807 Transfer material cassette 808a Separation claw 808b Separation push-up roller 809 Heat roller fixing device 810 Tray 811 Pre-exposure lamp 812 Potential sensor 813 Light amount detector 814 Fur brush 815 Backup brush 816 Oil removal roller 817 Backup brush 819 Transport path switching guide 820 Transport vertical path 21a Inversion path 821b Inversion roller 822 Intermediate tray 824y Eccentric cam 824c Eccentric cam 824m Eccentric cam 824Bk Eccentric cam 825 Eccentric cam 830 Document 831 Platen glass 832 Exposure lamp 833 Lens 834 Full color sensor 901 Electrophotographic photosensitive member 902 Corona charger 903a Polygon mirror 903c Mirror 904c Developing device 904y Developing device 904m Developing device 904Bk Developing device 905 Transfer material transport belt 907 Transfer material cassette 909 Fixing device 950 Transfer charger

Claims (9)

An electrophotographic photosensitive member having a photosensitive layer on a cylindrical support; an electrophotographic photosensitive member unit having a fitting member fitted to an end of the electrophotographic photosensitive member; and an oscillation wavelength in a range of 380 to 450 nm. An exposure unit having a laser, wherein a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam irradiated from the laser is 40 μm or less. ,
An electrophotographic apparatus, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 1.5 times or less of a spot diameter (Di [μm]) of the beam spot.   2. The electrophotographic apparatus according to claim 1, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is equal to or less than 1.0 times a spot diameter (Di [μm]) of the beam spot.   3. The electrophotographic apparatus according to claim 2, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 0.5 times or less of a spot diameter (Di [μm]) of the beam spot. A process cartridge comprising an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support and an electrophotographic photosensitive member unit having a fitting member fitted to an end of the electrophotographic photosensitive member,
An exposure unit having a laser having an oscillation wavelength in a range of 380 to 450 nm, and a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam emitted from the laser. In a process cartridge detachable from an electrophotographic apparatus having a size of 40 μm or less,
A process cartridge wherein the cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 1.5 times or less the spot diameter (Di [μm]) of the beam spot.   5. The process cartridge according to claim 4, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is equal to or less than 1.0 times a spot diameter (Di [μm]) of the beam spot.   The process cartridge according to claim 5, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 0.5 times or less a spot diameter (Di [μm]) of the beam spot. An electrophotographic photosensitive member having a photosensitive layer on a cylindrical support and an electrophotographic photosensitive member unit having a fitting member fitted to an end of the electrophotographic photosensitive member,
An exposure unit having a laser having an oscillation wavelength in a range of 380 to 450 nm, and a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam emitted from the laser. In an electrophotographic photoreceptor unit used for an electrophotographic apparatus having a particle size of 40 μm or less,
An electrophotographic photoreceptor unit, wherein a cylindrical deflection (De [μm]) of the electrophotographic photoreceptor unit is 1.5 times or less the spot diameter (Di [μm]) of the beam spot.   The electrophotographic photoreceptor unit according to claim 7, wherein a cylindrical deflection (De [μm]) of the electrophotographic photoreceptor unit is 1.0 times or less a spot diameter (Di [μm]) of the beam spot.   9. The electrophotographic photoconductor unit according to claim 8, wherein a cylindrical deflection (De [μm]) of the electrophotographic photoconductor unit is 0.5 times or less of a spot diameter (Di [μm]) of the beam spot.

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