JP4387779B2 - Electrophotographic equipment - Google Patents

Description

The present invention relates to an electrophotographic equipment.

Conventionally, various systems such as an electrophotographic system, a thermal transfer system, and an ink jet system have been adopted for an image forming apparatus. Among these, an image forming apparatus that employs an electrophotographic system, that is, an electrophotographic apparatus, has advantages in terms of high speed, high image quality, and quietness as compared with an image forming apparatus that employs another system. Yes.
Further, not only monochrome electrophotographic apparatuses but also multicolor electrophotographic apparatuses (color electrophotographic apparatuses) have become widespread.

  There are various types of color electrophotographic apparatuses. For example, exposure and development are performed one color at a time on one electrophotographic photosensitive member, and each color toner image is transferred onto an intermediate transfer member (intermediate transfer drum, intermediate transfer belt, etc.). After the primary transfer, the intermediate transfer method that forms a color image by batch transfer onto the transfer material, and the image forming unit for each color (electrophotographic photosensitive member / charging) arranged in series A toner image of each color is formed on a transfer material which is sequentially conveyed to each image forming portion by a transfer material conveying member (such as a transfer material conveying belt). Inline method for forming a color image by sequentially transferring to each other, and one color electrophotographic photosensitive member is used for exposure and development sequentially for each color, and each color toner image is carried on a transfer material carrying member (transfer drum, etc.). 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 due to the increasing needs for ultra-high resolution and ultra-high image quality of electrophotographic apparatuses. Among various approaches, the relationship between the electrophotographic photosensitive member and the exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member is considered to be particularly important because it forms the basis of image formation. ing. For example, in Japanese Patent No. 3254833 (Patent Document 1), in a system using a laser beam as exposure light (image exposure light), the writing pitch of the laser beam and the cylindrical electrophotographic photosensitive member (photosensitive drum) are disclosed. The relationship with the overall deflection is described.

  However, no matter how fine the laser beam writing pitch is, if the spot diameter (beam spot diameter) of the beam spot formed on the surface of the electrophotographic photosensitive member by the laser beam is not reduced, ultra-high resolution and ultra-high image quality You cannot get a good picture.

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

Further, it is known from the diffraction limit of the laser beam shown in the following formula (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 having a short oscillation wavelength (blue semiconductor laser), which has been put into practical use for DVDs or 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 made considerably small (40 μm or less) while maintaining the sharpness of the beam spot outline. Therefore, super high resolution can be achieved, which is very advantageous for super high image quality.

Japanese Patent No. 3254833 Japanese Patent Laid-Open No. 9-240051

  Generally, members for rotating and driving the electrophotographic photosensitive member in the electrophotographic apparatus are fitted to both ends of the cylindrical electrophotographic photosensitive member. Examples of the member (fitting member) 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 using a laser having an oscillation wavelength in the range of 380 to 450 nm and reducing the spot diameter of the beam spot (40 μm or less), a so-called electronic device in which fitting members are fitted to both ends of the electrophotographic photosensitive member. A very high accuracy is required for the photoconductor unit.

  If the accuracy of the electrophotographic photosensitive member unit is poor, the amount of change in the distance (imaging distance) between the electrophotographic photosensitive member and the exposure means increases, so that a beam spot is formed on the surface of the electrophotographic photosensitive member during laser beam irradiation. Accurate formation becomes difficult, and image roughness (halftone image non-uniformity, roughness) tends to occur.

  Furthermore, if the accuracy of the electrophotographic photoreceptor unit is poor, the amount of change in the gap or nip pressure between the electrophotographic photoreceptor and the developing member (developing roller, developing sleeve, etc.) becomes large during development. In the case of roughness (halftone image non-uniformity, roughness) or color image output, color misregistration is likely to occur. Further, since the positional accuracy between the electrophotographic photosensitive member and the transfer member or transfer paper becomes insufficient at the time of transfer, color misregistration is likely to occur in the case of color image output.

  However, there has been no prior art that focuses on the accuracy of the electrophotographic photoreceptor unit in order to solve these problems. In other words, even with an electrophotographic apparatus that uses a laser having an oscillation wavelength in the range of 380 to 450 nm to reduce the spot diameter of the beam spot, at present, it is necessary to achieve super high resolution and super high image quality image output. It was insufficient.

An object of the present invention is to solve the above-mentioned problems in an electrophotographic apparatus in which the spot diameter of a beam spot is reduced using a laser having an oscillation wavelength in the range of 380 to 450 nm. in the Hisage Kyosu Rukoto an electrophotographic apparatus capable.

As a result of intensive studies to solve the above problems, the present inventors have used an electrophotographic photoreceptor 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. As for the accuracy of the unit, we found that the cylindrical deflection has the deepest connection with the above-mentioned issues and is likely to affect the output of ultra-high resolution and ultra-high image quality.
In addition, the present inventors are able to output an image with an ultra-high resolution and an ultra-high image quality only when the cylindrical shake of the electrophotographic photosensitive member unit has a certain relationship with the spot diameter of the beam spot. I found it.

That is, the present invention relates to an electronic cylindrical support and the cylindrical electrophotographic having a photosensitive layer provided on a support a photosensitive member and the electrophotographic photosensitive member was fitted to an end of the electrophotographic photosensitive member An electrophotographic photoreceptor unit having a fitting member for rotationally driving in a photographic apparatus, and an exposure unit having a laser whose oscillation wavelength is in the range of 380 to 450 nm, and a laser beam emitted from the laser In an electrophotographic apparatus in which a spot diameter (Di [μm]) of a beam spot formed on the surface of the electrophotographic photosensitive member is 40 μm or less,
The electrophotographic apparatus is characterized in that a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 0.68 times or less of a spot diameter (Di [μm]) of the beam spot.

According to the present invention, in an electrophotographic apparatus in which the spot diameter of a beam spot is reduced using a laser having an oscillation wavelength in the range of 380 to 450 nm, an electrophotographic apparatus capable of outputting an image with ultra-high resolution and ultra-high image quality. as possible out to provide.

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

In the present invention, the spot diameter of the beam spot is represented by a portion until the intensity is reduced to A × 1 / e ² where A is the peak intensity. 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 obtained by dividing the image forming region into eight in the longitudinal direction, and the average value of the nine points was defined as the spot diameter (Di [μm]) of the beam spot.
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 is 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 Melles Griot.

  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 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 shake measuring machine.
In FIG. 2, the electrophotographic photosensitive member unit 201 that is the 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 arrow direction. The distance between the reference gauge 202 and the electrophotographic photosensitive member unit 201 manufactured with extremely high precision is measured by a laser beam 203 installed above the electrophotographic photosensitive member unit 201.

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

The cylindrical shake of the electrophotographic photosensitive member unit was measured for a total of 72 points, that is, 9 points obtained by dividing the image forming area into 8 parts in the longitudinal direction and 8 points obtained by dividing the image forming area into 8 parts in 45 degree increments in the circumferential direction. The difference between the maximum value and the minimum value was defined as the cylindrical shake (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 each adapted to a fitting member (such as a gear as a driving member or a 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), since the amount of change in the distance (imaging distance) between the electrophotographic photosensitive member and the exposure means is small, a beam spot is formed on the surface of the electrophotographic photosensitive member during laser beam irradiation. Can be formed accurately.

Furthermore, during development, since the amount of change in the gap or nip pressure between the electrophotographic photosensitive member and the developing member (developing roller, developing sleeve, etc.) becomes small, image roughness due to uneven development (non-uniformity in the halftone image, roughness) ) And color image output, no color misregistration occurs. Further, since the positional accuracy between the electrophotographic photosensitive member and the transfer member or transfer paper is sufficient at the time of transfer, color misregistration does not occur in the case of color image output.
Therefore, it is possible to output an image with an ultra-high resolution and an ultra-high image quality.

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, Further, it is more preferably 0.5 times or less (De / Di ≦ 0.5).
As a method of reducing the cylindrical shake (De [μm]) of the electrophotographic photosensitive member unit, there is a method of improving the accuracy of the electrophotographic photosensitive member, for example, reducing the cylindrical shake of the electrophotographic photosensitive member. In addition, 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 can also be mentioned.

  As a method for 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, reducing the deflection of the cylindrical support of the electrophotographic photosensitive member. . Specifically, methods such as increasing the thickness of the cylindrical support, cutting the inside of both ends of the cylindrical support, and cutting the surface of the cylindrical support are included.

  The method of improving the accuracy of the bonding part between the electrophotographic photosensitive member and the fitting member is to cut the inside of both ends of the cylindrical support, narrow the tolerance of the bonding part of the fitting member, and simultaneously cut the inner and outer diameters with a cutting tool. The method of using the fitted member (flange) which was made is mentioned.

  Examples of a method for improving the accuracy of the fitting member with respect to the drive shaft include a method of increasing the coaxiality between the fitting member and the drive shaft.

  Note that the measurement of the cylindrical shake of the electrophotographic photosensitive member and the cylindrical shake of the cylindrical support are in accordance with the above-described method of measuring the cylindrical shake of the electrophotographic photosensitive unit, in place of the electrophotographic photosensitive unit 201. A body or a cylindrical support may be used as an object to be measured. In that case, the driving side receiving jig 205 and the driven side receiving jig 206 may have shapes that fit 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.

The photosensitive layer includes a charge generation layer containing a charge generation material and a charge transport material, even if it is a single layer type photosensitive layer (FIG. 3A) containing the charge transport material and the charge generation material in the same layer. The layered type (functionally separated type) photosensitive layer may be separated from the charge transporting layer, but the layered photosensitive layer is preferable from the viewpoint of electrophotographic characteristics. Further, in the laminated photosensitive layer, a normal layer type photosensitive layer (FIG. 3B) laminated in order from the support side to the charge generation layer and the charge transport layer, and a charge transport layer and charge generation layer from the support side in this order. Although the reverse layer type photosensitive layer (FIG. 3C) is present, a normal layer type photosensitive layer is preferable from the viewpoint of electrophotographic characteristics.
3A, 3B, and 3C, reference numeral 301 denotes a support, 302 denotes a photosensitive layer, 303 denotes a charge generation layer, and 304 denotes a charge transport layer.

The support only needs to have conductivity, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, platinum, or other metal (alloy). The support can be used. In addition, the above metal (alloy) support or plastic support (polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) having a layer formed by vacuum deposition of these metals can also be used. . Also, impregnating plastic or paper with appropriate binder resin and the above metal support or plastic support with conductive particles such as carbon black and silver particles coated with appropriate binder resin. It is also possible to use a support or a plastic containing a conductive binder resin.
Further, as the support, in order to suppress the cylindrical shake of the electrophotographic photosensitive member unit, a support having a small cylindrical shake of the support itself is preferable as described above.

  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 for covering scratches 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, still more preferably 10 μm or more, and on the other hand, it is preferably 40 μm or less, 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 adhesion of the photosensitive layer, improving the coating property, improving the charge injection property from the support, and protecting the photosensitive layer from electrical breakdown. The intermediate layer can be formed using materials such as polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, glue, and gelatin. The film thickness of the intermediate layer is preferably 0.05 to 5 μm, more preferably 0.2 to 3.0 μm.

  The charge generating material used in the electrophotographic photosensitive member used in the present invention has an absorption in the wavelength range of 380 to 450 nm, and has the sensitivity necessary to obtain a full color image with an ultra high resolution and an ultra high image quality. It is preferable to use phthalocyanine pigments such as metal phthalocyanine and nonmetal phthalocyanine and azo pigments such as monoazo, disazo and trisazo, or a mixture of two or more. In addition, cationic dyes such as pyrylium dyes, thiapyrylium dyes, azurenium dyes, thiocyanine dyes, and quinocyanine dyes, polycyclic quinone pigments such as squalium salt dyes, anthanthrone pigments, dibenzpyrenequinone pigments, and pyranthrone pigments, and indigo A pigment, a quinacridone pigment, a perylene pigment, or the like may be used.

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge generation layer include 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 singly or in combination of two or more as a mixture or copolymer. The amount of 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 and drying a charge generation layer coating solution obtained by dispersing a charge generation material together with a binder resin and a solvent. 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 material and the binder resin is preferably in the range of 1: 0.1 to 1: 4 (mass ratio), and more 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 binder resin used and the solubility and dispersion stability of the charge generation material, such as tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, and the like. Ethers, ketones such as cyclohexanone, methyl ethyl ketone, pentanone, amines such as N, N-dimethylformamide, esters such as methyl acetate and ethyl acetate, aromatics such as toluene, xylene and chlorobenzene, methanol, ethanol, 2 Examples include alcohols such as -propanol, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene.

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

  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 necessary.

  Examples of the charge transport material 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 materials, polymerized materials of these electron-withdrawing materials, or polycyclic aromatic compounds such as pyrene and anthracene, carbazole compounds, indole compounds, oxazole compounds, thiazole compounds, oxalates Hole transport materials such as heterocyclic compounds such as diazole compounds, pyrazole compounds, pyrazoline compounds, thiadiazole compounds, triazole compounds, hydrazone compounds, styryl compounds, benzidine compounds, triarylmethane compounds, and triphenylamine compounds Is mentioned. These can be used alone or in admixture 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 singly or in combination of two or more as a mixture or copolymer.

  Further, light having the function of a binder resin and a charge transport material such as a polymer having a group derived from the charge transport material in the main chain or side chain (for example, poly-N-vinylcarbazole, polyvinyl anthracene, etc.) A conductive resin may be used.

  The charge transport layer can be formed by applying and drying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent. 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 ethers such as tetrahydrofuran and dimethoxymethane, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and 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, a coating method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, a blade coating method or the like can be used.

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

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

In the case where the photosensitive layer is a normal layer type, it is preferable to select a charge transport material or a binder resin that is highly transmissive with respect to the wavelength of the laser beam used.
When the photosensitive layer is a single layer type, the single layer type photosensitive layer comprises a coating solution for a single layer type photosensitive layer obtained by dispersing the charge generation material and the charge transport material together with the binder resin and the solvent. It can be formed by applying and drying.

Further, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer from mechanical external force or chemical external force, and for the purpose of improving transferability and cleaning property.
The protective layer is for 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 form by apply | coating a coating liquid and drying.

  In order to provide the protective layer with a charge transporting capability, the protective layer may be formed by curing a monomer material having a charge transporting capability 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 photo CVD.

Furthermore, you may include electroconductive particle, a ultraviolet absorber, an abrasion resistance improving agent, etc. in a protective layer. As the conductive particles, for example, metal oxides such as tin oxide particles are preferable. As the wear resistance improver, fluorine resin fine powder, alumina, silica and the like are preferable.
In addition, conductive particles, ultraviolet absorbers, wear resistance improvers, and the like can be added to the protective layer as necessary. 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 0.5 to 20 μm, and particularly preferably 1 to 10 μm.

  In the present invention, the surface layer of the electrophotographic photosensitive member refers to a single-layer type photosensitive layer in the case of a layer structure (single-layer type) as shown in FIG. 3A, as shown in FIG. In the case of a simple layer structure (forward layer type), it indicates a charge transport layer, and in the case of a layer structure (reverse layer type) as shown in FIG. 3C, it indicates a charge generation layer. Moreover, when providing a protective layer in these, this protective layer becomes a surface layer of an electrophotographic photoreceptor.

Next, the developer used in the present invention will be described.
The developer is roughly classified into a two-component developer composed of toner and carrier and a one-component developer composed only of toner. Further, it can be roughly divided 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 amount of toner having a particle size of 5 μm or less is less than 17% by number, the consumption may increase. Furthermore, 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, The tendency becomes more remarkable in the dot resolution of 20 to 40 μm. At this time, even if an attempt is made to develop with an unreasonable design under other development conditions, line thickening and toner scattering are likely to occur, and it is difficult to obtain stable developability such as an increase in toner consumption. On the other hand, when the toner having a particle size of 5 μm or less exceeds 90% by number, it is difficult to obtain a stable developability, which may cause problems 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, particularly 3.2 μm ≦ Dv ≦ 5.8 μm, It is more preferable that 3.6 μm ≦ D4 ≦ 6.3 μm.

  Examples of the binder resin used for the toner include styrene homopolymers or styrene copolymers such as polystyrene, styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers, and styrene-butadiene copolymers. Examples thereof include polyester resins, epoxy resins, and petroleum resins.

  From the viewpoint of improving the releasability from the fixing member at the time of fixing and improving the fixing property, it is preferable to contain wax in the toner. Examples of the wax include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, carnauba wax and derivatives thereof, and the like. Examples of the derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. In addition, long chain alcohols, long chain fatty acids, acid amide compounds, ester compounds, ketone compounds, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, mineral waxes, petrolactams and the like can also be used.

  As the colorant used in 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, Rhodamun lake, Alizarin lake, Bengala, Examples include phthalocyanine blue and indanthrene blue. The ratio between the colorant and 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 composed of magnetic iron oxide such as triiron tetroxide and γ-iron oxide are preferable.
For the purpose of controlling charging of the toner, the toner may contain a nigrosine dye, a quaternary ammonium salt, a salicylic acid metal complex, a salicylic acid metal salt, a salicylic acid derivative metal complex, salicylic acid, acetylacetone, or the like.

  Further, the toner preferably has a structure in which inorganic fine powder is externally added to toner particles. By externally adding inorganic fine powder to the toner particles, development efficiency, reproducibility of the 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. It is done. These may be used alone or in combination of two or more. Among these, fine powders of oxides or double oxides such as titania, alumina, and silica are preferable.

The inorganic fine powder added externally 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. As the hydrophobizing treatment method, a method of treating with an organic metal compound such as a silane coupling agent or a titanium coupling agent that reacts with or physically adsorbs on the inorganic fine powder, a treatment with a silane coupling agent, or And a method of treating with an organosilicon compound such as silicone oil at the same time as treating 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 0% by mass with respect to the toner particles. More preferably, it is 2-3 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 added to the toner within a range that does not substantially adversely affect the toner. For example, lubricant powder such as polytetrafluoroethylene powder, zinc stearate powder, polyvinylidene fluoride powder, abrasive 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 development improvers such as organic fine particles and inorganic fine particles having a polarity opposite to that of the toner. Can be mentioned.

  In order to produce the toner, a known method can be employed. For example, binder resin, wax, metal salt or metal complex, colorant, and if necessary, magnetic substance, charge control agent, and other additives are thoroughly mixed by a mixer such as a Henschel mixer or a ball mill, Dissolve or dissolve metal salt or metal complex, colorant, magnetic substance, etc. in melt-kneading using a heat kneader such as a heating roll, kneader, extruder etc. Thereafter, the toner can be obtained by strictly performing pulverization and classification. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

  In addition, by dispersing a polymerizable monomer, a colorant and the like in an aqueous solvent to perform polymerization, and directly dispersing the polymer fine particles obtained by a method for producing toner particles, an emulsion polymerization method or the like in an aqueous medium, At the same time, the toner can be prepared by a method of associative fusion.

  In the case of a two-component developer, examples of the magnetic carrier include powders such as magnetic ferrite, magnetite, and iron, and those coated with a resin such as an acrylic resin, a silicone resin, or 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 are in contact is preferable, and a reversal developing method is used. 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 rotationally driven in a direction of an arrow about a shaft 2 at a predetermined peripheral speed. Further, fitting members (a driving member and / or a bearing member) are fitted to both ends of the electrophotographic photosensitive member 1 in order to rotationally drive 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 means (primary charging means) 3, and then exposed to exposure means (non-exposure means such as slit exposure or laser beam scanning exposure). The exposure light (image exposure light) 4 output from the figure is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the surface of the electrophotographic photosensitive member 1.

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

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

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

  Now, since 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 poor, the electrophotographic photosensitive member is exposed during laser beam irradiation. 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 (developing roller, developing sleeve, etc.) increases during development. The technical problem that the unevenness of the image due to unevenness (halftone image non-uniformity, roughness) is likely to occur is a general technical problem of the electrophotographic apparatus, but particularly in the case of a color electrophotographic apparatus. If the accuracy of the body unit is poor, the amount of change in the gap or nip pressure between the electrophotographic photosensitive member and the developing member (developing roller, developing sleeve, etc.) during development will be 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, when the electrophotographic apparatus is a color electrophotographic apparatus, the present invention exhibits its effect more remarkably.

  Hereinafter, as an example of a color electrophotographic apparatus, an intermediate transfer type color electrophotographic apparatus, an inline type color electrophotographic apparatus, and a multiple transfer type color electrophotographic apparatus will be described. In the following description, examples of four colors (yellow, magenta, cyan, and black) are given. However, the “color” in the present invention is not limited to four colors (so-called full color), and is multicolored. 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 means is mainly composed of 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 at a predetermined peripheral speed in the direction of the arrow about the shaft 2. In addition, a fitting member (a driving member and / or a bearing member) is fitted to both ends of the electrophotographic photosensitive member 1 in order to rotationally drive 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 to be rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging means (primary charging means) 3, and then exposed to exposure means (non-exposure means such as slit exposure or laser beam scanning exposure). The exposure light (image exposure light) 4 output from the figure is received. The exposure light at this time is exposure light corresponding to the first color component image (for example, yellow component image) of the target color image. In this way, the 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 photoreceptor 1.

  The intermediate transfer member (intermediate transfer belt) 11 stretched by the stretching roller 12 and the secondary transfer counter roller 13 has substantially the same peripheral speed as 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 photosensitive member 1 is developed with the first color toner (yellow toner) contained in the developer of the first color developing means (yellow developing means) 5Y. Thus, a first color toner image (yellow toner image) is obtained. Next, the first color toner image formed and supported on the surface of the electrophotographic photoreceptor 1 is transferred between the electrophotographic photoreceptor 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 member 11 passing between them.
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 image formation of the next color. The

  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 photoreceptor 1 in the same manner as the first color toner image. And sequentially transferred onto the surface of the intermediate transfer body 11. Thus, a synthetic 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 body 11 is transferred from the transfer material supply means (not shown) to the secondary transfer counter roller 13 and the intermediate transfer body 11 by the secondary transfer bias from the secondary transfer member 6s. Secondary transfer is sequentially performed on the transfer material (paper or the like) P taken out and fed in synchronization with the rotation of the intermediate transfer body 11 between the next transfer member 6s (contact portion).
The transfer material P that has received the transfer of the synthetic toner image is separated from the surface of the intermediate transfer body 11 and introduced into the fixing means 8 to undergo image fixing to print out as a color image formed product (print, copy) outside the apparatus. Be out.

  The charge applying means 7r is brought into contact with the surface of the intermediate transfer body 11 after the synthetic toner image is transferred. The charge imparting means 7r imparts a charge having a reverse polarity to that of the secondary transfer remaining developer (toner) on the surface of the intermediate transfer body 11 to that of the primary transfer. The developer (toner) remaining in the secondary transfer to which a charge having a polarity opposite to that at the time of primary transfer is applied is in contact with 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 member 11 after the transfer of the synthetic toner image is cleaned by the removal of the developer (toner) remaining after transfer. 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 surface of the electrophotographic photosensitive member 1. Since the transfer of the developer (toner) remaining after the secondary transfer from the intermediate transfer member 11 to the electrophotographic photosensitive member 1 can be performed simultaneously with the primary transfer, the throughput is not reduced.

  Further, the surface of the electrophotographic photoreceptor 1 after the developer (toner) remaining after transfer by the cleaning means 7 may be removed by pre-exposure light from the pre-exposure means, but as shown in FIG. When the charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.

FIG. 6 shows an example of a schematic configuration of an inline type color electrophotographic apparatus. In the case of the inline method, the transfer means is mainly composed of a transfer material conveying member and a transfer member.
In FIG. 6, reference numerals 1Y, 1M, 1C, and 1K denote cylindrical electrophotographic photosensitive members (first to fourth color electrophotographic photosensitive members), and the directions of the arrows are about axes 2Y, 2M, 2C, and 2K, respectively. Are rotated at a predetermined peripheral speed. In addition, fitting members (drive members and / or bearing members) are provided at both ends of the electrophotographic photoreceptors 1Y, 1M, 1C, and 1K to rotationally drive the electrophotographic photoreceptors 1Y, 1M, 1C, and 1K, respectively. It is fitted (not shown), and the electrophotographic photosensitive member unit for the first color is constituted by the electrophotographic photosensitive member 1Y and the fitting member. The electrophotographic photosensitive member 1M and the fitting member constitute the second color electron. A photographic photoreceptor unit is constituted, and the electrophotographic photoreceptor unit for the third color is constituted by the electrophotographic photoreceptor 1C and the fitting member, and the fourth color electron is constituted by the electrophotographic photoreceptor 1K and the fitting member. It constitutes a photographic photosensitive unit.

  The surface of the rotationally driven first color electrophotographic photosensitive member 1Y is uniformly charged to a predetermined positive or negative potential by a first color charging means (first color primary charging means) 3Y, and then slits Exposure light (image exposure light) 4Y output from exposure means (not shown) such as exposure and laser beam scanning exposure is received. 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. 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 first color electrophotographic photoreceptor 1Y.

  The transfer material conveyance member (transfer material conveyance belt) 14 stretched by the tension roller 12 has substantially the same peripheral speed as the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, 1K in the direction of the arrow ( For example, it is rotationally driven at 97 to 103% of the peripheral speeds of the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K. Further, the transfer material (paper or the like) P fed from the transfer material supply means (not shown) is electrostatically carried (adsorbed) on the transfer material conveying member 14 and is electrophotographic for the first to fourth colors. The photoreceptors 1Y, 1M, 1C, and 1K are sequentially transported between the transfer material transport members (contact portions).

  The first color component electrostatic latent image formed on the surface of the first color electrophotographic photoreceptor 1Y is developed with the first color toner contained in the developer of the first color developing means 5Y, and the first color toner is developed. An image (yellow toner image) is formed. Next, the first color toner image formed and supported on the surface of the first color electrophotographic photosensitive member 1Y is transferred to the first color by the transfer bias from the first color transfer member (first color transfer roller) 6Y. The image is sequentially transferred to the transfer material P carried on the transfer material transport member 14 that passes between the electrophotographic photosensitive member 1Y and the first color transfer member 6Y.

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

  The first color electrophotographic photoreceptor 1Y, the first color charging means 3Y, the first color exposure means, the first color developing means 5Y, and the first color transfer member 6Y are grouped together to form a first color image forming section. Called.

  A second color image forming unit having a second color electrophotographic photoreceptor 1M, a second color charging unit 3M, a second color exposure unit, a second color developing unit 5M, and a second color transfer member 6M; A third color image forming unit having a third color electrophotographic photoreceptor 1C, a third color charging unit 3C, a third color exposure unit, a third color developing unit 5C, and a third color transfer member 6C; The fourth color image forming section having the fourth color electrophotographic photoreceptor 1K, the fourth color charging means 3K, the fourth color exposure means, the fourth color developing means 5K, and the fourth color transfer member 6K. The operation is the same as the operation of the first color image forming section, and the second color toner image (magenta toner image) is carried on the transfer material P which is carried on the transfer material conveying member 14 and to which the first color toner image is 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 composite toner image corresponding to the target color image is formed on the transfer material P carried on the transfer material conveying member 14.

  The transfer material P on which the synthetic toner image is formed is separated from the surface of the transfer material conveying 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). Out.

  Also, the first to fourth color electrophotographic photoreceptors 1Y, 1M, 1C, and 1K after removal of the developer (toner) remaining after the transfer by the first to fourth color cleaning means 7Y, 7M, 7C, and 7K. However, as shown in FIG. 6, the first to fourth color charging means 3Y, 3M, 3C, and 3K are provided with a charging roller or the like as shown in FIG. In the case of the contact charging means used, pre-exposure is not always necessary.

  In FIG. 6, 15 is an adsorption roller for adsorbing the transfer material to the transfer material conveying member, and 16 is a separation charger for separating the transfer material from the transfer material conveying 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 is mainly composed of a transfer material carrying member and a transfer charger.
In FIG. 7, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which is driven to rotate about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. In addition, a fitting member (a driving member and / or a bearing member) is fitted to both ends of the electrophotographic photosensitive member 1 in order to rotationally drive 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 to be rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging means (primary charging means) 3, and then exposed to exposure means (non-exposure means such as slit exposure or laser beam scanning exposure). The exposure light (image exposure light) 4 output from the figure is received. The exposure light at this time is exposure light corresponding to the first color component image (for example, yellow component image) of the target color image. In this way, the 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 photoreceptor 1.

  The transfer material carrying member (transfer drum) 17 is rotationally driven in the arrow direction at substantially the same peripheral speed as that of the electrophotographic photosensitive member 1 (for example, 97 to 103% with respect to the peripheral speed of the electrophotographic photosensitive member 1). A transfer material (paper or the like) P fed from a transfer material supply means (not shown) is electrostatically carried (adsorbed) on the transfer material carrying member 17, and the electrophotographic photosensitive member 1 and the transfer material carrying member. Between the two (contact portion).

  The first color component electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed with the first color toner (yellow toner) contained in the developer of the first color developing means (yellow developing means) 5Y. Thus, a first color toner image (yellow toner image) is obtained. Next, a transfer material in which the first color toner image formed and supported on the surface of the electrophotographic photoreceptor 1 passes between the electrophotographic photoreceptor 1 and the transfer charger 6co by a transfer bias from the transfer charger 6co. Transfer is performed on the transfer material P carried on the carrying member 17.

  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 transfer residual developer (toner), and then used for image formation of the next color. .

  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 photoreceptor 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 first color toner image, and the second color toner image (cyan toner image) are transferred to the transfer material P on which the first color toner image is transferred. A four-color toner image (black toner image) is 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 carrying member 17.

  The transfer material P on which the synthetic toner image has been formed is separated from the surface of the transfer material carrying member 17 and 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). Out.

  Further, the surface of the electrophotographic photosensitive member 1 after the transfer residual developer (toner) is removed by the cleaning unit 7 may be subjected to a static elimination process with the pre-exposure light from the pre-exposure unit, but as shown in FIG. When the charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.

  In FIG. 7, reference numeral 15a denotes an adsorption roller for adsorbing the transfer material to the transfer material carrying member, 15b denotes an adsorption charger for adsorbing the transfer material to the transfer material carrying member, and 16 denotes the transfer material carrying. It 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, like the electrophotographic apparatus having the configuration shown in FIG. 4, the electrophotographic photosensitive member unit, charging means, developing means, transfer means, cleaning means, etc. Among the components, a plurality of components may be housed in a container and integrally combined as a process cartridge, and the process cartridge may be configured to be detachable from an electrophotographic apparatus main 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, “part” means “part by mass”.

Example 1
FIG. 8 shows a schematic configuration of the 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 the original platen glass 831 and exposed and scanned by the exposure lamp 832, whereby the reflected light image from the original 830 is condensed on the full-color sensor 834 by the lens 833, and the full-color color separation image signal is obtained. Get. The full-color color separation image signal is processed by a video processing unit (not shown) through an amplifier circuit (not shown) and sent to the printer unit.

  In the printer unit, 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 are a pre-exposure lamp 811 (6 fuse lamps in series x 2 in parallel, 550 nm or less cut with a filter, pre-exposure means), a corona charger 802 (charging means), , A laser exposure optical system 803 (including an exposure unit equipped with a GaN chip manufactured by Nichia Chemical Co., Ltd. having an oscillation wavelength of 405 nm and an output of 5 mW), a potential sensor 812, a yellow developer 804y, cyan Development unit 804c, magenta development unit 804m and black development unit 804Bk (development unit), light amount detector 813 on the surface of the electrophotographic photosensitive member, transfer unit, and cleaning unit 806 (cleaning unit). ing. The developing devices 804y, 804c, 804m, and 804Bk each have a developing sleeve.

In the laser exposure optical system 803, the 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 and The light is projected onto 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 spot diameter in the main scanning direction was 28 μm and the spot diameter in the sub scanning direction 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 the charge is removed by the pre-exposure lamp 811 is uniformly charged negatively by the corona charger 802. The light image 800E is irradiated for each color, and an electrostatic latent image is formed on the surface of the electrophotographic photoreceptor 801.

  Next, a predetermined developing device is operated to develop the electrostatic latent image on the surface of the electrophotographic photosensitive member 801, and a developed image is formed on the surface of the electrophotographic photosensitive member 801 using a two-component developer (using negative toner). To do. The developing unit is configured to approach the electrophotographic photosensitive member 801 alternatively according to 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 supplied from a transfer material cassette 807 containing paper (transfer material) to a position facing the electrophotographic photosensitive member 801 through a conveyance system and transfer means. Transcript to.
The transfer means includes a transfer drum 805a, a transfer charger 805b, an adsorption roller 805g facing the adsorption charger 805c for electrostatically adsorbing paper, an inner charger 805d, and an outer charger 805e. The transfer drum 805a that is pivotally supported so as to be rotationally driven has a transfer material carrying sheet 805f that is integrally stretched in a cylindrical shape in the peripheral opening area. A polycarbonate film that is a dielectric sheet is used as the transfer material carrying sheet 805f.

As the transfer drum 805a is rotated, the developed image on the surface of the electrophotographic photosensitive member 801 is transferred to the paper carried on the transfer material carrying sheet 805f of the transfer drum 805a by the transfer charger 805b.
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, thereby forming a full color image.
In the case of forming a full-color image, when the transfer of the developed images of the 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 fixing Paper is discharged to the tray 810 through the device 809.

On the other hand, the electrophotographic photosensitive member 801 after the transfer is subjected to the image forming process again after the developer remaining on the surface is cleaned by the cleaning device 806.
When forming images on both sides of the paper, after discharging the heat roller fixing device 809, the conveyance path switching guide 819 is driven immediately, and after passing through the conveyance vertical path 820, it is once guided to the reversing path 821a, and then the reversing roller. Due to the reverse rotation of 821b, the rear end when it is fed in is moved backward in the direction opposite to the feeding direction and stored in the intermediate tray 822. Thereafter, an image is formed on the other surface again by the image forming process described above.

  Further, in order to prevent the powder from adhering to the transfer material carrying sheet 805f of the transfer drum 805a and the oil from adhering to the 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 removal roller 816 via the brush 815, the oil removal roller 816, and the transfer material carrying sheet 805f. Such cleaning is performed before or after image formation, and is performed as needed when a paper jam occurs.

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

The electrophotographic photoreceptor used in this example was prepared by the following procedure.
Cylindrical runout: 10 μm, length: 360 mm, diameter: 180 mm, 10-point average roughness Rzjis: 0.4 μm of a cut aluminum cylinder (Furukawa Electric Co., Ltd.) was used as a support.
In the present invention, the 10-point average roughness Rzjis is measured based on JIS B0601 (2001) using a surf coder SE-3500 (manufactured by Kosaka Laboratory Ltd.) with a cut-off of 0.8 mm. The length was 8 mm.

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

Next, 30 parts of methoxymethylated nylon resin (number average molecular weight: 32000) and 10 parts of alcohol-soluble copolymer nylon resin (number average molecular weight: 29000) were dissolved in a mixed solvent of 260 parts of methanol / 40 parts of butanol. Thus, an intermediate layer coating solution was prepared.
This intermediate layer coating solution was dip coated on the conductive layer and dried to form an intermediate layer having a thickness of 1 μm.

Next, the Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction are 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 °. Crystal parts 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 were used with glass beads having a diameter of 1 mm. The mixture was dispersed in a sand mill for 3 hours, and then 250 parts of ethyl acetate was added to prepare a charge generation layer coating solution.
The charge generation layer coating solution was dip coated on the intermediate layer 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:

And 10 parts of 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 charge transport layer.

This charge transport layer coating solution was dip coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 13 μm.
In this way, a cylindrical electrophotographic photosensitive member having a 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 unit. The cylindrical deflection (De) of this electrophotographic photosensitive member unit was 15 μm.

  The electrophotographic photosensitive member unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 to output a full-color image, and the output full-color image output was visually evaluated. The dark portion potential (charging potential) was set to −700 V, the light portion potential was set to −200 V, and the developing bias was set to −550 V.

The evaluation results are shown in Table 1. In Table 1, the evaluation criteria for roughness (non-uniformity of the halftone image, roughness) and color misregistration are AA: None A: Almost no B: Inconspicuous C: Some D: Conspicuous E: Very conspicuous is there.

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

( Reference Example 3)
In Example 1, the support was changed to a cut aluminum cylinder (manufactured by Furukawa Electric Co., Ltd.) having a cylindrical runout of 31 μm, a length of 360 mm, a diameter of 180 mm, and a 10-point average roughness Rzjis of 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:

And 10 parts of 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).

  The charge transport layer (first charge transport layer) coating solution 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 ( (Product name: GF300, manufactured by Toa Synthetic Chemical Industry Co., Ltd.) 0.24 parts, 120 parts of monochlorobenzene, and 80 parts of methylal were dispersed and mixed in an ultrahigh pressure disperser. In addition, 3 parts of a charge transport material (A) having a structure represented by the following formula

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

This coating solution for the protective layer (second charge transport layer) 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 then the abrasive sheet (Wrapping tape, abrasive particles: alumina, abrasive particle diameter: # 3000, manufactured by Fuji Photo Film Co., Ltd.), the surface was polished for 1 minute, and the film thickness was 3 μm and the 10-point average roughness Rzjis was 0.7 μm. A protective layer (second charge transport layer) was formed.
In this way, a cylindrical electrophotographic photoreceptor 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 unit. The cylindrical deflection (De) of this electrophotographic photosensitive member unit was 40 μm.
As in Example 1, this electrophotographic photosensitive member unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 to output a full-color image, and the output full-color image output was visually evaluated. The evaluation results are shown in Table 1.

に変更した以外は、参考例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。 ( Reference Example 4)
In Reference Example 2, the azo pigment having a structure represented by the following formula in which hydroxygallium phthalocyanine used in the charge generation layer is represented

The electrophotographic photosensitive member was produced in the same manner as in Reference Example 2 except that the electrophotographic photosensitive member unit was changed, and 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 28 μm.

As in Reference Example 2, this electrophotographic photosensitive member unit was mounted on a full-color electrophotographic apparatus having the configuration shown in FIG. 8 to perform full-color image output, and the output full-color image output was visually evaluated. The evaluation results are shown in Table 1.

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

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

(Comparative Example 3)
The electrophotographic photosensitive member and the electrophotographic photosensitive member unit are the same as in Reference Example 3, except that the beam spot diameter is set to 25 μm (the main scanning direction spot diameter is 22 μm and the sub scanning direction spot diameter is 28 μm). Were made and evaluated. The evaluation results are shown in Table 1.

( Reference Example 5)
In Comparative Example 3, the electrophotographic photosensitive member and the electrophotographic photosensitive member unit were changed to the electrophotographic photosensitive member and the electrophotographic photosensitive member unit produced in the same manner as in Reference Example 2, and evaluated in the same manner as in Comparative Example 3. The evaluation results are shown in Table 1.

(Comparative Example 4)
In Reference Example 3, the GaN chip mounted on the laser exposure optical system 803 of the full-color electrophotographic apparatus used for the evaluation was changed to an AlGaInP 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 Reference Example 3 except that the direction beam spot diameter was set to 55 μm and the sub-scanning direction spot diameter was set to 65 μm. The evaluation results are shown in Table 1.

(Example 6)
In Example 1, except that the support was changed to a drawn aluminum cylinder (made by Showa Aluminum Co., Ltd.) having a cylindrical runout of 15 μm, a length of 360 mm, a diameter of 30 mm, a 10-point average roughness Rzjis of 0.8 μm. Then, an electrophotographic photosensitive member was produced in the same manner as in Example 1, and 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 21 μm.

This electrophotographic photosensitive member unit was mounted on a full-color electrophotographic apparatus (in-line method) having the configuration shown in FIG. 9 to output a full-color image, and the output full-color image output was visually evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.
The laser exposure optical system of the full-color electrophotographic apparatus having the configuration shown in FIG. 9 is equipped with a GaN-based chip manufactured by Nichia Corporation with 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 (main scanning direction spot diameter: 28 μm, sub-scanning direction spot diameter: 34 μm).

  In FIG. 9, 901 is an electrophotographic photosensitive member, 902 is a corona charger, 903a is a polygon mirror, 903c is a mirror, 904c, 904y, 904m, and 904Bk are developers, 905 Is a transfer material conveying 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。 ( Reference Example 7)
In Example 6, the 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 with an ultrahigh pressure disperser to form a protective layer (second charge A coating solution for 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 an electron beam in nitrogen under the conditions of an acceleration voltage of 150 kV and a dose of 1.5 Mrad. Next, heat treatment is performed for 3 minutes under the condition that the temperature of the electrophotographic photosensitive member is 120 ° C. (the oxygen concentration at this time is 20 ppm), and then the electrophotographic photosensitive member is 110 ° C. in the atmosphere. A post-treatment was performed for 1 hour to form a protective layer (second charge transport layer) having a thickness of 5 μm.
In this way, a cylindrical electrophotographic photoreceptor 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 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. The evaluation results are shown in Table 1.

(Comparative Example 5)
In Example 6, the GaN chip mounted on the laser exposure optical system of the full-color electrophotographic apparatus used for evaluation was changed to a GaAlAs chip (oscillation wavelength: 780 nm), and the beam spot diameter was 56 μm (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. The evaluation results are shown in Table 1.

(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. The evaluation results are shown in Table 1.

As described above, according to the present invention, in an electrophotographic apparatus in which the spot diameter of a beam spot is reduced by using a laser having an oscillation wavelength in the range of 380 to 450 nm, it is possible to output an image with ultrahigh resolution and ultrahigh image quality. it is as possible out to provide an electrophotographic apparatus.

It is a figure for demonstrating the measuring method of the spot diameter (Di [micrometer]) of a beam spot. It is a figure which shows schematic structure of a cylindrical run-out measuring machine. It is a figure which shows the structure of a photosensitive layer. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge. 1 is a diagram illustrating an example of a schematic configuration of an intermediate transfer type color electrophotographic apparatus. FIG. 1 is a diagram illustrating an example of a schematic configuration of an inline type color electrophotographic apparatus. FIG. 1 is a diagram illustrating an example of a schematic configuration of a multiple transfer type color electrophotographic apparatus. FIG. It is a figure which shows schematic structure of the full-color electrophotographic apparatus used in Example 1 and Reference Examples 2-5. It is a figure which shows schematic structure of the full-color electrophotographic apparatus used in Example 6 and Reference Example 7. FIG.

Explanation of symbols

A Peak intensity D1 Spot diameter D2 of the beam spot in the main scanning direction Spot diameter 201 of the beam spot in the sub scanning direction 201 Electrophotographic photosensitive member unit 202 Reference gauge 203 Laser beam 204 Base 205 Drive side receiving jig 206 Drive 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 Axis 3 Charging Unit 4 Exposure Light 5 Developing Unit 6 Transfer Unit 7 Cleaning Unit 8 Fixing Unit 9 Process Cartridge 10 Guide Unit P Transfer Material 5Y First color developing means 5M Second color developing means 5C Third color developing means 5K Fourth color developing means 6p Primary transfer member 6s Secondary transfer member 7r Charge applying means 11 Intermediate transfer body 12 Stretching roller 13 Secondary transfer counter roller 1Y First color electrophotographic photosensitive member 1M Second color Electrophotographic photosensitive member 1C third color electrophotographic photosensitive member 1K fourth color electrophotographic photosensitive member 2Y axis 2M axis 2C axis 2K axis 3Y first color charging means 3M second color charging means 3C third color charging Means 3K 4th 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 First 1-color transfer member 6M 2nd-color transfer member 6C 3rd-color transfer member 6K 4th-color transfer member 7Y 1st-color cleaning means 7M 2nd-color cleaning means 7C 3rd-color cleaning means 7K 4th Color cleaning means 14 Transfer material conveying member 15 Adsorption roller 16 Separation charger 6co Transfer charger 15a Adsorption roller 15b Adsorption charger 17 Transfer material carrying member 800E Optical image 801 Electrophotographic photoreceptor 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 Adsorption roller 805h Separation charger 805i Cam follower 806 Cleaning device 807 Transfer material cassette 808a Separation claw 808b Separation push 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 Reverse path 821b Reverse roller 822 Intermediate tray 824y Eccentric cam 824c Eccentric cam 824m Eccentric cam 824Bk Eccentric cam 825 Eccentric cam 830 Document 831 Document table glass 832 Exposure lamp 833 Lens 834 Full color sensor 901 Electrophotographic photoreceptor 902 Corona charger 903a Polygon mirror 903c Mirror 904c Developer 904y Developer 904m Developer 904Bk Developer 905 Transfer material transport belt 907 Transfer material cassette 909 Fixer 950 Transfer charger

Claims (4)

An electrophotographic photosensitive member having a cylindrical support and a photosensitive layer provided on the cylindrical support, and the electrophotographic photosensitive member fitted to an end of the electrophotographic photosensitive member are driven to rotate in an electrophotographic apparatus. An electrophotographic photosensitive member unit having a fitting member for carrying out, and an exposure means having a laser whose oscillation wavelength is in the range of 380 to 450 nm, and the electrophotographic photosensitive member is irradiated with a laser beam emitted from the laser. In the electrophotographic apparatus in which the spot diameter (Di [μm]) of the beam spot formed on the surface is 40 μm or less,
An electrophotographic apparatus, wherein a cylindrical deflection (De [μm]) of the electrophotographic photosensitive member unit is 0.68 times or less of a spot diameter (Di [μm]) of the beam spot. It said electrophotographic photosensitive member unit cylindrical deflection (De [μm]) is, the beam spot of the spot diameter (Di [μm]) The electrophotographic apparatus according to claim 1 is 0.5 times or less. The electrophotographic apparatus according to claim 1 or 2, wherein the engaging member is a drive member or the bearing member. The electrophotographic film according to claim 1, wherein the photosensitive layer is formed by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material in this order from the cylindrical support side. apparatus.

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