JP2005300740A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an a-Si photoreceptor which prevents image flow, without depending on the photoreceptor heater of a system to be held turned on with electricity all the day long and, to reduce a standby power requirement at night by enabling easy removal of the deposits to be the cause for the image flow, prevents cleaning defects, such as toner fusion and toner wearing off during cleaning, and can maintain satisfactory image formation over a long period of time. <P>SOLUTION: Varying sizes of the surface roughness Ra in a range of 10 μm×10 μm of the a-Si photoreceptor are formed alternately in the direction of the generatrix. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member (hereinafter referred to as an a-Si photosensitive member) having an amorphous silicon photoconductive layer, which can be applied to an image forming apparatus using an electrophotographic process such as a copying machine, a printer, and a fax machine. Is.

  2. Description of the Related Art Conventionally, a-Si photoconductors have been proposed in which a fine shape on the surface of the photoconductor is defined for the purpose of improving cleaning properties and preventing image flow in a high humidity environment.

  Among them, there is one which stipulates that the surface roughness Ra in the range of 10 μm × 10 μm is 15 nm or more and 100 nm or less (for example, see Patent Document 1).

In addition, the ratio of the center line average roughness Ra1 of the photoconductive layer surface side interface to the center line average roughness Ra2 of the outermost surface layer in the range of 10 μm × 10 μm is defined, and the surface of the photoreceptor is subjected to a polishing treatment. is there.
Japanese Patent Laid-Open No. 2001-330978 JP 2001-281896

  However, in the above conventional example, the distribution of the surface roughness Ra in the direction of the photoreceptor bus is not controlled, and thus there are the following problems.

  In an image forming apparatus using an a-Si photoconductor, an image flow in which the surface of the photoconductor becomes low resistance due to adhesion on the surface of the photoconductor, particularly in a high humidity environment, and the printed image is reduced in density or blurred. There is a problem that an image defect called “is prone to occur”. Examples of deposits on the surface of the photoreceptor include toner, fine paper dust generated from paper used as a recording material, organic components precipitated therefrom, and corona products generated due to the presence of a high-pressure member in the apparatus. Can be mentioned. These deposits react with moisture particularly in a high humidity environment to lower the resistance of the surface of the photoreceptor, thereby preventing the formation of a clear electrostatic latent image and contributing to deterioration of image quality.

  In the a-Si photoconductor, these deposits are liable to cause image flow because the surface of the a-Si photoconductor is extremely harder than the organic photoconductor, and therefore the deposits are caused by the abrasion of the photoconductor itself. This is because is hardly removed. For this reason, as a measure for preventing the image flow, a method of suppressing moisture absorption on the surface of the photoreceptor by providing an all-day energization type photoreceptor heater has been generally used.

  However, in recent years, for such image forming apparatuses, as seen in the Blue Angel and Energy Star programs, improvement in environmental adaptability by energy saving is demanded as a social demand. Therefore, there is a need for a technique that can handle the image flow of an a-Si photoconductor without using the all-day energization type photoconductor heater that requires standby power.

  Accordingly, an object of the first invention according to the present application is to facilitate removal of deposits that cause image flow, thereby preventing image flow without relying on an all-day energization type photoreceptor heater, and night standby power. It is an object to provide an a-Si photosensitive member capable of reducing the above.

  Further, the object of the second invention according to the present application is to prevent image flow and at the same time to prevent poor cleaning such as toner fusing and toner rub-off during cleaning, so that good image formation can be maintained for a long time. -To provide a Si photoconductor.

  Furthermore, an object of the third invention according to the present application is to provide an a-Si photoconductor capable of easily obtaining the effects of the present invention without deteriorating the photoconductor characteristics and productivity.

  In order to achieve the above object, the invention according to the present application is characterized in that in the a-Si photoconductor, the surface roughness Ra in the range of 10 μm × 10 μm of the photoconductor is alternately formed in the direction of the bus. .

  The present inventors have inferred the following mechanism of improving the image flow when the nighttime photoconductor heater is turned off by alternately forming Ra in the bus direction.

  Under high-temperature and high-humidity conditions, when the photoconductor heater is turned off at night, moisture is adsorbed on the photoconductor surface during standing at night and reacts with adhering substances such as corona products to reduce the surface resistance. A surface state is formed where flow is likely to occur. Therefore, in order to suppress the image flow at the start in the morning, moisture and deposits on the surface of the photosensitive member must be quickly removed during the warm-up after the power is turned on.

  Therefore, by alternately forming the size of Ra in the direction of the bus, the mechanism is not clear, but the effect of removing deposits by the interaction between the elastic roller and the cleaning blade constituting the cleaner and the surface of the photoreceptor is promoted, and the image flow Is presumed to have improved.

  Further, it is presumed that the deposit removal effect is further promoted and the image flow is further improved by controlling the intervals at which Ra is alternately formed in the bus direction.

  Further, the present inventors presume the mechanism that the cleaning failure such as toner fusion and toner scraping is improved by the maximum value and the minimum value of Ra as follows.

  In particular, when paper passing durability is performed using a test pattern with a reduced printing rate, the supply of toner to the cleaner is insufficient, and as a result, the distribution of toner and external additives on the elastic roller in the cleaner is uneven. May occur, and the rubbing effect on the photosensitive member may not be sufficiently obtained. This reduction in the rubbing effect is likely to appear remarkably in a low temperature / low humidity environment.

  Therefore, the size of Ra is alternately formed in the direction of the bus, and the maximum value and the minimum value of Ra are controlled to appropriate values, so that the elastic roller and the cleaning blade constituting the cleaner have a rubbing effect on the photosensitive member. It is presumed that the cleaning defect such as toner fusion and toner rub-off is improved.

  In addition, regarding the mechanism that the cleaning failure such as toner fusion and toner scraping is improved by the area ratio of Ra large and small, the cleaner is configured when the areas of Ra large and small have a certain area ratio. The present inventors presume that the sliding effect on the photosensitive member by the elastic roller and the cleaning blade is improved.

  Further, the size of Ra is alternately formed in the direction of the bus in accordance with the peaks and valleys of the support, so that the minimum value of Ra exists in the peak of the support and the maximum value of Ra exists in the valley of the support. As a result, regarding the mechanism of improving the image flow when the photoconductor heater at night is turned off, the undulations and the magnitudes of Ra on the surface of the photoconductor and Ra, the elastic roller and the cleaning blade constituting the cleaner The present inventors speculate that the effect of removing the adhering matter is further promoted by the synergistic action, and the image flow is remarkably improved.

  As described above, according to the first invention of the present application, it is possible to provide an a-Si photoconductor capable of preventing image flow without relying on an all-day energization type photoconductor heater. In comparison, the standby power at night can be greatly reduced. Furthermore, at the same time, it is possible to provide a photoreceptor that can prevent poor cleaning such as toner fusion and toner scraping during cleaning and maintain good image formation over a long period of time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

“A-Si photoconductor according to the present invention”
First, the configuration of a general a-Si photoreceptor will be described. FIG. 3 is a schematic sectional view schematically showing the layer structure of the a-Si photosensitive member according to the present invention.

  In the electrophotographic photoreceptor 100 shown in FIG. 3A, a light receiving layer 102 is provided on a conductive substrate 101. The photoreceptive layer 102 is composed of an a-Si lower charge injection blocking layer 105 and a photoconductive layer having a photoconductivity composed of a-Si: H or a-Si: (H, X) in order from the conductive substrate 101 side. 103 and an a-SiC-based surface layer 104.

  In the electrophotographic photoreceptor 100 shown in FIG. 3B, a lower charge injection blocking layer 105, a photoconductive layer 103, and a surface layer 104, which are photoreceptive layers 102, are similarly provided on a conductive substrate 101 in this order. Yes. Furthermore, the photoconductive layer 103 is composed of a first layer region 1031 and a second layer region 1032 and is functionally separated. Further, interface control is performed in which the interface between the photoconductive layer 103 and the surface layer 104 is continuously changed to suppress interface reflection.

  The electrophotographic photosensitive member 100 shown in FIG. 3 (c) is also formed on the conductive substrate 101. The lower charge injection blocking layer 105, the photoconductive layer 103, and the a-SiC-based upper charge injection blocking, which are the light receiving layer 102, are provided. A layer 106 and a surface layer 104 are provided in this order. Further, interface control is performed in which the interface between the photoconductive layer 103 and the upper charge injection blocking layer 106 and between the upper charge injection blocking layer 106 and the surface layer 104 is continuously changed to suppress interface reflection.

  The impurity atoms contained in each of these layers are atoms belonging to Group 13 of the periodic table (hereinafter abbreviated as Group 13 atoms) and atoms belonging to Group 15 of the periodic table (hereinafter abbreviated as Group 15 atoms). By selecting from the above, it is possible to control the charging polarity such as positive charging or negative charging.

  Further, the surface layer 104 contains a-SiC (H, X) containing a hydrogen atom and a halogen atom as required, a nitrogen atom as a base material, and a hydrogen atom and a halogen atom as needed. It may be formed of a-SiN (H, X), a-C (H, X) containing a carbon atom as a base and a hydrogen atom and a halogen atom as necessary.

  Hereinafter, the conductive substrate and each functional layer constituting the a-Si photoreceptor will be described in more detail.

<Conductive substrate>
Examples of the material for the conductive substrate used in the present invention include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Can be mentioned.

  In addition, as a base material, a film or sheet of a synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, or polyamide, or an electrically insulating material such as glass or ceramic is used. The surface on the side where the light-receiving layer is produced can be subjected to a conductive treatment and used as a conductive substrate.

  The shape of the conductive substrate to be used can be a smooth surface or a cylindrical or endless belt type having a minute uneven surface, and the thickness is appropriately determined so that a desired electrophotographic photosensitive member can be formed. To do. When flexibility as an electrophotographic photosensitive member is required, it can be made as thin as possible within a range where the function as a conductive substrate can be sufficiently exhibited. However, it is usually preferable that the conductive substrate is 10 μm or more from the viewpoint of mechanical strength and the like in manufacturing and handling.

<Photoconductive layer>
For the photoconductive layer formed on the conductive substrate and constituting at least a part of the photoreceptive layer, numerical conditions of film forming parameters are appropriately set so that desired characteristics can be obtained, for example, by a vacuum deposition layer forming method, Moreover, the raw material gas etc. to be used are selected and produced. Specifically, glow discharge method (low frequency CVD method, high frequency CVD method or AC CVD method such as microwave CVD method, or direct current discharge CVD method), sputtering method, vacuum deposition method, ion plating method, light It can be produced by various thin film deposition methods such as a CVD method and a thermal CVD method.

  These thin film deposition methods are appropriately selected and adopted depending on factors such as manufacturing conditions, degree of load under capital investment, manufacturing scale, and characteristics desired for the electrophotographic photosensitive member to be produced. The high frequency glow discharge method is preferred because the control of the conditions for producing the electrophotographic photosensitive member is relatively easy.

  In order to form a photoconductive layer by the glow discharge method, basically, a Si supply source gas capable of supplying silicon atoms (Si), and a H supply source gas capable of supplying hydrogen atoms (H) are provided. The raw material gas for supplying X, which can supply halogen atoms (X), if necessary, is introduced in a desired gas state into a reaction vessel whose inside can be depressurized to cause glow discharge in the reaction vessel. A layer made of a-Si: H or a-Si: (H, X) may be formed on a predetermined conductive substrate that is previously set at a predetermined position.

  Hydrogen atoms in the photoconductive layer, and further halogen atoms added as necessary, compensate for dangling bonds of silicon atoms in the layer and improve layer quality, in particular, photoconductivity and charge retention characteristics. When a hydrogen atom content or a halogen atom is added, the sum of the hydrogen atom and halogen atom content is preferably 1 to 40 atom% based on the total amount of the constituent atoms.

As substances that can serve as Si supply gas, gaseous substances such as SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , Si ₄ H ₁₀ , or silicon hydrides (silanes) that can be gasified are effectively used. Further, SiH ₄ and Si ₂ H ₆ are preferable from the viewpoints of easy handling at the time of layer preparation, good Si supply efficiency, and the like.

Desirably, H ₂ , He, silicon compound gas containing hydrogen atoms, etc. are added to these gases so that hydrogen atoms are structurally introduced into the formed photoconductive layer and the introduction ratio of hydrogen atoms is controlled. The layer may be formed in a mixed atmosphere. In addition, each gas may be mixed not only with a single species but also with a plurality of species at a predetermined mixing ratio.

Preferable examples of the raw material gas for supplying the halogen atom include gaseous substances such as halogen gas, halides, interhalogen compounds containing halogen, silane derivatives substituted with halogen, or halogenated compounds that can be gasified. Furthermore, a gaseous substance containing silicon atoms and halogen atoms as constituent elements, or a silicon hydride compound containing a halogen atom that can be gasified can also be mentioned as effective. Specific examples thereof include fluorine gas (F ₂ ) and halogen compounds such as BrF, ClF, ClF ₃ , BrF ₃ , BrF ₅ , IF ₃ , and IF ₇ . Specific examples of silicon compounds containing halogen atoms, so-called silane derivatives substituted with halogen atoms, include silicon fluorides such as SiF ₄ and Si ₂ F ₆ .

  Furthermore, in the present invention, it is preferable that the photoconductive layer contains an atom for controlling conductivity as required. Atoms for controlling conductivity may be contained in a state of being uniformly distributed in the photoconductive layer, or there may be a portion containing them in a non-uniform distribution state in the layer thickness direction.

  Furthermore, in the present invention, functional separation can be achieved by changing the content of atoms that control conductivity in the first and second layer regions of the photoconductive layer. In particular, when it is contained in a non-uniform distribution state in the layer thickness direction, the distribution state is preferably reduced from the conductive substrate side to the surface layer side, and the second layer region is compared with the first layer region. It is more preferable to make it contain in the distribution state that content of a layer area | region decreases. In addition, it is also effective to contain in a distributed state in which the content in the layer thickness direction decreases toward the surface side only in the second layer region.

  Examples of the atoms that control conductivity include so-called impurity atoms in the semiconductor field, and group 13 atoms and group 15 atoms can be used.

  Specific examples of the Group 13 atom include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl), and B, Al, and Ga are particularly preferable. . The group 15 atom includes phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), etc., and P and As are particularly preferable.

The content of atoms for controlling conductivity contained in the photoconductive layer is preferably 5 × 10 ^{14 to} 5 × 10 ¹⁸ atoms / cm ³ , more preferably 1 × 10 ¹⁵ to 1 × 10 ¹⁸ atoms / cm. ³ and optimally 5 × 10 ^{15 to} 5 × 10 ¹⁷ atoms / cm ³ are desirable.

  In order to structurally introduce the atoms for controlling the conductivity, when forming the layer, the source material of the gas for supplying the atoms for controlling the conductivity is in a gas state to form the photoconductive layer in the reaction vessel. What is necessary is just to introduce with other gas. As a material that can be used as a source material for the atom supply gas for controlling conductivity, it is desirable to employ a gaseous material at normal temperature and pressure, or a material that can be easily gasified at least under the conditions of layer formation.

Specifically, as a raw material for introducing such group 13 atoms, for introducing boron atoms, B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ , Examples thereof include boron hydrides such as B ₆ H ₁₂ and B ₆ H ₁₄ , and boron halides such as BF ₃ , BCl ₃ and BBr ₃ . In addition, AlCl ₃ , GaCl ₃ , Ga (CH ₃ ) ₃ , InCl ₃ , TlCl _{3 and the} like can also be mentioned. Specific examples of the source material for introducing Group 15 atoms include phosphorus hydrides such as PH ₃ and P ₂ H ₄ , phosphorus halides such as PF ₃ and PCl _3, etc. It is done. In addition, AsH ₃ , AsF ₃ , AsF ₅ , AsCl ₃ , SbH ₃ , SbF ₅ , BiH _{3 and the} like can also be mentioned.

Further, the starting material for introducing atoms for controlling the conductivity may be diluted with H ₂ and / or He if necessary.

  In the present invention, the layer thickness of the photoconductive layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 10 to 50 μm, more preferably 20 to 45 μm, optimally Is preferably 25 to 40 μm. If the layer thickness is less than 10 μm, the electrophotographic characteristics such as charging ability and sensitivity may be insufficient in practical use. If the layer thickness is greater than 50 μm, the photoconductive layer may be manufactured for a long time and the manufacturing cost may be increased. is there.

  In the present invention, the film thickness of the second layer region of the photoconductive layer is desirably 0.5 μm or more and 15 μm or less.

  If the thickness of the second layer region is less than 0.5 μm, the amount of light absorbed by the laser or LED will be small, and light will reach the deep part of the first layer region, reducing the ghost level and linearity of sensitivity There is a case. On the other hand, if the thickness is greater than 15 μm, the residual potential and dark decay increase, and the sensitivity may decrease.

  In order to form the photoconductive layer described above, it is necessary to appropriately set the mixing ratio of the Si supply gas and the dilution gas, the gas pressure in the reaction vessel, the discharge power, and the conductive substrate temperature.

The optimum flow rate of H ₂ and / or He used as a dilution gas is appropriately selected according to the layer design, but H ₂ and / or He is usually 0.5 to 20 times the volume of Si supply gas. It is desirable to control within the range of preferably 1 to 15 times the volume, and most preferably 1 to 10 times the volume.

Similarly, the optimum gas pressure in the reaction vessel is appropriately selected according to the layer design, but preferably 1 × 10 ⁻² to 1 × 10 ³ Pa, more preferably 5 × 10 ^{−2 to} 5 × 10 ² Pa. The optimum value is 1 × 10 ⁻¹ to 1 × 10 ² Pa.

  Similarly, the optimum range of the discharge power is also selected according to the layer design. The ratio of the discharge power [W] to the flow rate [ml / min (normal)] of the Si supply gas is preferably 0.5 to 20, preferably It is desirable to set in the range of 1-12.

  Further, the temperature of the conductive substrate is appropriately selected in accordance with the layer design, but in the usual case, it is preferably 150 to 350 ° C, more preferably 160 to 320 ° C, and most preferably 180 to 300 ° C. Is desirable.

  Although the above-mentioned ranges can be mentioned as the desirable numerical ranges of the conductive substrate temperature and gas pressure for forming the photoconductive layer, the conditions are not usually determined separately, but electrophotography having desired characteristics It is desirable to determine an optimum value based on mutual and organic relevance in order to form a photoreceptor.

<Surface layer>
In the present invention, an a-Si surface layer can be formed on the photoconductive layer formed on the conductive substrate. This surface layer has a free surface, and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.

  In addition, since each of the amorphous materials forming the photoconductive layer and the surface layer constituting the photoreceptive layer has a common component called silicon atoms, chemical stability can be ensured at the laminated interface. Well made.

  The surface layer can be made of any material of the a-Si system. For example, the surface layer contains a hydrogen atom (H) and / or a halogen atom (X), and further contains a carbon atom containing a-Si (a-SiC). : (H, X)), a hydrogen atom (H) and / or a halogen atom (X), and further containing a nitrogen atom, a-Si (a-SiN: (H, X) ) And the like are preferably used. A material such as a-C (also expressed as aC: (H, X)) containing a hydrogen atom (H) and / or a halogen atom (X) as a base is also preferably used.

  The layer thickness of the surface layer is preferably 0.01 to 3 μm, more preferably 0.05 to 2 μm, and still more preferably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer may be lost due to wear or the like during use of the electrophotographic photosensitive member, and if it exceeds 3 μm, the residual potential may increase and the electrophotographic characteristics may deteriorate. .

  Further, a lower portion having a function of preventing charge injection between the photoconductive layer and the surface layer, wherein the content of one or more atoms selected from carbon atoms, oxygen atoms or nitrogen atoms is reduced from the surface layer. Providing a surface layer is also effective for further improving characteristics such as charging ability.

  In addition, the interface between the surface layer and the photoconductive layer may be continuously changed so that the content of one or more atoms selected from the atoms included in the surface layer decreases toward the photoconductive layer. good. As a result, the adhesion between the surface layer and the photoconductive layer can be improved, and the influence of interference due to reflection of light at the interface can be further reduced.

<Lower charge injection blocking layer>
In the electrophotographic photosensitive member of the present invention, it is more effective to provide a lower charge injection blocking layer that functions to block charge injection from the conductive substrate side between the conductive substrate and the photoconductive layer. is there. That is, the lower charge injection blocking layer has a function of blocking charge injection from the conductive substrate side to the photoconductive layer side when the photoreceptive layer is subjected to charging treatment of a certain polarity on its free surface, Such a function is not exhibited when a reverse polarity charging process is performed, so-called polarity dependency is provided. In order to provide such a function, the lower charge injection blocking layer contains a relatively large number of atoms for controlling conductivity compared to the photoconductive layer.

  The atoms controlling the conductivity contained in the lower charge injection blocking layer may be uniformly distributed in the layer, or may be uniformly contained in the layer thickness direction but in a non-uniformly distributed state. There may be contained parts. When the distribution concentration is not uniform, it is preferable to contain it so as to be distributed in a large amount on the conductive substrate side.

  However, in any case, it is necessary to contain in a uniform distribution in the in-plane direction parallel to the surface of the conductive substrate in order to achieve uniform characteristics in the in-screen direction.

  As the atoms controlling the conductivity contained in the lower charge injection blocking layer, Group 13 atoms and Group 15 atoms can be used.

  Further, the lower charge injection blocking layer contains at least one of carbon atom, nitrogen atom and oxygen atom, thereby improving adhesion with other layers provided in direct contact with the lower charge injection blocking layer. It can be improved.

  One or more atoms of carbon atom, nitrogen atom and oxygen atom contained in the lower charge injection blocking layer may be uniformly distributed in the layer or are uniformly contained in the layer thickness direction. However, there may be a portion that is contained in a non-uniformly distributed state. However, in any case, in the in-plane direction parallel to the surface of the conductive substrate, it is necessary to contain it in a uniform distribution from the viewpoint of achieving uniform characteristics in the in-plane direction.

  The layer thickness of the lower charge injection blocking layer is preferably 0.1 to 10 μm, more preferably 0.3 to 5 μm, still more preferably 0.5 to 3 μm from the viewpoints of obtaining desired electrophotographic characteristics and economic effects. When the layer thickness is less than 0.1 μm, the ability to prevent injection of charges from the conductive substrate may be insufficient, and sufficient charging ability may not be obtained. On the other hand, even if it is thicker than 5 μm, the manufacturing cost may be increased by extending the manufacturing time rather than substantially improving the electrophotographic characteristics.

<Upper charge injection blocking layer>
In the electrophotographic photosensitive member of the present invention, it is effective to provide an upper charge injection blocking layer according to the charge polarity such as positive charge or negative charge.

  The upper charge injection blocking layer prevents injection of charges from the upper part, particularly in a negatively charged electrophotographic photosensitive member, and improves charging ability, and a large amount of photocarriers are generated by irradiation with strong exposure. It also plays the role of preventing the so-called EV flow, that is, the image flow at the time of strong exposure in which the character portion is blurred due to the phenomenon of flowing into a portion that is easy to move.

  The upper charge injection blocking layer of the present invention contains a desired amount of Group 13 atoms and Group 15 atoms in a non-single-crystal silicon film having carbon atoms and silicon atoms as base materials, so that the charge polarity is opposite to the charged polarity. It is preferable to adjust to an optimum resistance value that does not flow laterally while passing the carrier.

  The upper charge injection blocking layer may be any material as long as it is an a-Si-based material. For example, the upper charge injection blocking layer contains a hydrogen atom (H) and / or a halogen atom (X), and further contains a carbon atom. a-SiC: (H, X) is preferred.

  The upper charge injection blocking layer contains a relatively large amount of atoms that control conductivity as compared to the photoconductive layer. The atoms controlling the conductivity contained in the upper charge injection blocking layer may be distributed uniformly in the layer, or may be uniformly contained in the layer thickness direction but in a non-uniformly distributed state. There may be contained parts. When the distribution concentration is not uniform, it is preferable to contain it so as to be distributed in a large amount on the surface layer side.

  However, in any case, it is necessary to contain the material in a uniform distribution in the in-plane direction parallel to the surface of the conductive substrate in order to achieve uniform characteristics in the in-screen direction.

  The layer thickness of the upper charge injection blocking layer may be determined by comprehensive judgment based on the layer thicknesses of the photoconductive layer and the surface layer and the required electrophotographic characteristics. The design is usually from 0.01 μm to 0.5 μm so that the ability to prevent charge injection from the surface is fully exhibited and the image quality is not affected.

“Measuring method of surface roughness Ra of photoconductor according to the present invention”
For the surface roughness Ra of the photoreceptor according to the present invention, a value calculated from an AFM observation image measured by an atomic force microscope (AFM: Q-SCOPE 250 (Version 3.181) manufactured by Quesant) is used. It was. The AFM has a horizontal resolution of 0.5 nm or more and a vertical resolution of 0.01 to 0.02 nm, and a large difference from the conventionally used surface roughness meter is in its high resolution. Only with such a high resolution, the nano-scale surface roughness of the a-Si film is quantified without being affected by the macroscopic roughness of the order of several tens to several hundreds of micrometers, where the substrate shape is dominant. It becomes possible to do.

  In order to quantify the microscopic surface roughness with good reproducibility, it is preferable to use an AFM observation image measured in a range of 10 μm × 10 μm. FIG. 9 shows an example of the result of measurement of the surface roughness Ra of the a-Si photosensitive member by the inventors changing the scan size indicating the length of one side of the AFM observation image. Increasing the scan size makes it difficult to reflect the fine shape of the a-Si film due to the undulation of the sample substrate, the unique shape such as the protrusion, and the processed shape. Conversely, if the scan size is reduced, the measurement location varies. Therefore, the present invention is represented by a 10 μm × 10 μm field of view that is excellent in overall detection ability and stability of measurement.

  Furthermore, it is preferable to use an AFM observation image measured so as not to be affected by the curvature and inclination of the surface of the photoreceptor. Specifically, it is preferable to appropriately perform necessary correction on the measured AFM observation image. For example, Parabolic Line by line correction may be performed using a Tilt Removal of Q-SCOPE 250 manufactured by Quesant. This removes the curvature and inclination of the measurement surface of the sample and flattens it, and is suitable for quantifying the microscopic surface roughness of the a-Si film from the cylindrical photoreceptor surface. It is a technique.

  Further, the surface roughness Ra of the present invention refers to a value calculated from an AFM observation image having a three-dimensional shape. The inventors extracted an arbitrary two-dimensional cross-sectional curve from an AFM observation image having a three-dimensional shape, and obtained Ra of the two-dimensional shape. The results generally coincided with Ra obtained from the three-dimensional shape. However, Ra obtained from the three-dimensional shape is more preferable in terms of the correspondence between measured value stability, image flow, and poor cleaning.

  An example of the AFM observation image is shown in FIGS. FIG. 10 shows an AFM observation image of a 10 μm × 10 μm field of view on the surface of the photoreceptor without any post-processing after the formation of the deposited layer, and FIG. It is an AFM observation image of a 10 μm × 10 μm field of view on the surface of the photoreceptor after polishing.

“Preferable range of distribution of surface roughness Ra”
The surface roughness Ra (value in the range of 10 μm × 10 μm measured by the above method) of the quantified photoconductor in this way is such that at least large and small distribution patterns are alternately formed in the generatrix direction of the photoconductor. Yes.

  Further, this distribution pattern is preferably at intervals of 10 μm or more and 200 μm or less, and more preferably at intervals of 80 μm or more and 150 μm or less. As a result, the effect of preventing the image flow of the present invention can be remarkably obtained.

  The Ra value is preferably in the range of 5 nm to 100 nm, the Ra value is preferably 5 nm to 20 nm, the Ra value is preferably 30 nm to 100 nm, and more preferably 5 nm to 20 nm. It is more preferable that the region is formed so that the area ratio is 20% or more of the whole and the area of 30 nm or more and 100 nm or less is 20% or more of the whole. As a result, poor cleaning can be remarkably prevented.

  Further, the surface shape of the support has undulations composed of peaks and valleys in the direction of the generatrix, and the surface roughness Ra in the range of 10 μm × 10 μm of the photoconductor is alternately formed according to the peaks and valleys of the support, Ra It is preferable to form such that the minimum value of lies in the peak portion of the support and the maximum value of Ra exists in the valley portion of the support. This configuration also enhances the effect of preventing image flow according to the present invention.

“A-Si photoconductor manufacturing apparatus according to the present invention”
Next, an example of the electrophotographic photoreceptor manufacturing apparatus and the deposited layer forming method according to the present invention will be described in detail.

  FIG. 6 is a schematic configuration diagram showing an example of an electrophotographic photoreceptor manufacturing apparatus using a high-frequency plasma CVD method (also abbreviated as RF-PCVD) using an RF band as a power supply frequency. The configuration of the manufacturing apparatus shown in FIG. 6 is as follows.

  This apparatus is roughly composed of a deposition apparatus 3100, a source gas supply apparatus 3200, and an exhaust apparatus (not shown) for reducing the pressure inside the reaction vessel 3111. A cylindrical conductive substrate 3112, a substrate heating heater 3113, a source gas introduction pipe 3114 are installed in a reaction vessel 3111 in the deposition apparatus 3100, and a high frequency matching box 3115 is further connected.

A raw material gas supply device 3200 includes SiH ₄ , NO, H ₂ , CH ₄ , B ₂ H ₆ , PH _{3 and} other raw material gas cylinders 3221 to 3226, valves 3231 to 3236, 3241 to 3246, 3251 to 3256, and a mass flow controller. Each of the source gas cylinders is connected to a gas introduction pipe 3114 in the reaction vessel 3111 via an auxiliary valve 3260.

  Formation of the deposited layer using this apparatus can be performed as follows, for example.

  First, the cylindrical conductive substrate 3112 is installed in the reaction vessel 3111, and the inside of the reaction vessel 3111 is evacuated by an unillustrated exhaust device (for example, a vacuum pump). Subsequently, the cylindrical conductive substrate 3112 is controlled to a desired temperature by the substrate heating heater 3113.

  In order to flow the deposition layer forming source gas into the reaction vessel 3111, confirm that the source gas cylinder valves 3231 to 3236 and the reaction vessel leak valve 3117 are closed, and the gas inflow valves 3241 to 3246, gas outflow After confirming that the valves 3251 to 3256 and the auxiliary valve 3260 are opened, first, the main exhaust valve 3118 is opened, and the inside of the reaction vessel 3111 and the raw material gas pipe 3116 is exhausted.

  Next, the auxiliary valve 3260 and the gas outflow valves 3251 to 3256 are closed when the reading of the vacuum gauge 3119 becomes about 0.1 Pa or less.

  Thereafter, each gas is introduced from the source gas cylinders 3221 to 3226 by opening the source gas cylinder valves 3231 to 3236, and each gas pressure is adjusted to 0.2 MPa by the pressure regulators 3261 to 3266. Next, the gas inflow valves 3241 to 3246 are gradually opened to introduce each gas into the mass flow controllers 3211 to 3216.

  After the preparation for film formation is completed as described above, each layer is formed according to the following procedure.

When the cylindrical conductive substrate 3112 reaches a predetermined temperature, necessary ones of the gas outflow valves 3251 to 3256 and the auxiliary valve 3260 are gradually opened, and a predetermined gas is supplied from the gas cylinders 3221 to 3226 through the gas introduction pipe 3114. Into the reaction vessel 3111. Next, the mass flow controllers 3211 to 3216 are adjusted so that each raw material gas has a predetermined flow rate. At that time, the opening of the main exhaust valve 3118 is adjusted while looking at the vacuum gauge 3119 so that the pressure in the reaction vessel 3111 becomes a predetermined pressure of 1 × 10 ³ Pa or less. When the internal pressure is stabilized, an RF power source (not shown) having a frequency of 13.56 MHz is set to a desired power, and RF power is introduced into the reaction vessel 3111 through the high-frequency matching box 3115 to cause glow discharge. The raw material gas introduced into the reaction vessel is decomposed by the discharge energy, and a deposited layer mainly composed of predetermined silicon is formed on the cylindrical conductive substrate 3112. After the formation of the desired film thickness, the supply of RF power is stopped, the outflow valve is closed, the gas flow into the reaction vessel is stopped, and the formation of the deposited layer is completed.

  By repeating the same operation a plurality of times, a desired multilayered light-receiving layer is formed. It goes without saying that all the gas outflow valves other than the necessary gas are closed when forming each layer, and each gas is transferred into the reaction vessel 3111 from the gas outflow valves 3251 to 3256 to the reaction vessel 3111. In order to avoid remaining in the pipes to reach, close the gas outflow valves 3251 to 3256, open the auxiliary valve 3260, and further open the main exhaust valve 3118 to evacuate the system once to high vacuum as necessary Do it. At this time, if necessary, each layer may be continuously formed by continuously changing the gas type and flow rate of the source gas.

  In order to make the film formation uniform, it is also effective to rotate the cylindrical conductive substrate 3112 at a predetermined speed by a driving device (not shown) during the layer formation.

  Furthermore, it goes without saying that the gas species and valve operations described above are changed according to the manufacturing conditions of each layer.

  The heating method of the conductive substrate may be a heating element that is vacuum specification, more specifically, an electric resistance heating element such as a sheathed heater, a plate heater, a ceramic heater, a halogen lamp, an infrared lamp, etc. And heat generating lamps using a heat exchanging means using a heat emitting lamp as a heating medium, liquid, gas or the like. As the surface material of the heating means, metals such as stainless steel, nickel, aluminum, and copper, ceramics, heat resistant polymer resin, and the like can be used.

  In addition to this, there is used a method in which a container dedicated to heating is provided in addition to the reaction container, and after heating, the conductive substrate is transported in the reaction container in a vacuum.

  The electrophotographic photosensitive member produced by the method as described above can be controlled to a surface roughness suitable for the present invention by appropriately selecting the production conditions.

  For example, in order to control the surface roughness of the photoreceptor, it is effective to adjust parameters such as high-frequency power and power frequency, gas flow rate, pressure, substrate temperature, and film thickness. It is also effective to vary the high frequency power in pulses.

  In general, as a condition for forming the surface of the deposited layer having a large surface roughness Ra, the precursor of the layer formation reaching the growth surface of the deposited layer is not sufficiently diffused, or the amount of the precursor reached is large. When sufficient time for diffusion is not obtained, a deposition layer is formed under conditions where a gas phase polymerization reaction easily occurs, and a deposition layer is formed while taking in a polymer generated in the gas phase. . Specifically, increasing the surface roughness Ra includes increasing the high frequency power, increasing the power frequency, increasing the gas flow rate, increasing the pressure, decreasing the substrate temperature, increasing the film thickness, etc. It is effective in. However, under such manufacturing conditions, the quality of the deposited layer may be degraded, and it is essential to adjust each parameter of the manufacturing conditions so as not to degrade the quality of the deposited layer as much as possible.

  Further, the manufacturing conditions for forming such a photoconductor having a large surface roughness Ra are preferably employed for the photoconductive layer which accounts for the majority of the photoconductor thickness in view of the effect. Conditions for controlling the surface roughness Ra may be employed only in the blocking layer and the surface protective layer that have little influence on the surface.

  Furthermore, the distribution of the surface roughness Ra can be controlled after the photosensitive member is produced by performing an etching process using an etching gas or plasma using the same electrophotographic photosensitive member manufacturing apparatus.

  Further, as a result of intensive studies by the present inventors, in order to control the surface roughness Ra of the photoreceptor over a wide range, the power frequency of the high frequency power for causing glow discharge is set to the VHF band (50 to 450 MHz). ) Was found to be particularly effective.

  FIG. 7 is a schematic configuration diagram showing an example of an electrophotographic photosensitive member manufacturing apparatus using a high-frequency plasma CVD method (also abbreviated as VHF-PCVD) using a VHF band as a power supply frequency. This manufacturing apparatus includes at least a reaction vessel 402 capable of containing a cylindrical conductive substrate 401, a source gas introduction pipe 417 for supplying a source gas into the reaction vessel 402, and an electric power for decomposing the source gas. A deposition apparatus 400 comprising a cathode 414 for introducing gas, a source gas supply apparatus 404 for supplying a source gas into the reaction container 402, an exhaust system 405 for exhausting the reaction container 402, and a power supply for supplying power to the cathode 414 Device 406.

  First, as a heating step, a cylindrical conductive substrate 401 is installed in the reaction vessel 402, the inside of the reaction vessel 402 is exhausted through an exhaust port 419 by an exhaust pump 407, and exhausting to a desired degree of vacuum is completed. An inert gas, such as He gas or Ar gas, is supplied into the reaction vessel 402 at a predetermined flow rate by a mass flow controller in the source gas supply device 404. Then, by adjusting the exhaust speed of the exhaust pump 407, the inside of the reaction vessel 402 is controlled to a desired pressure. After the internal pressure of the reaction vessel 402 is set to a desired pressure, the cylindrical conductive substrate 401 is heated to a desired temperature by the substrate heating heater 403. During the formation of the deposited layer, the desired temperature necessary for forming the deposited layer is maintained.

After the heating step is completed by the above procedure, a deposited layer forming step is subsequently performed. After the inert gas in the reaction vessel 402 is exhausted by the exhaust pump 407, the exhaust valve 408 is closed, the main exhaust valve 409 is opened, the throttle valve 410 is fully opened, and the reaction is performed by the oil diffusion pump 411 and the rotary pump 412. The inside of the container 402 is evacuated to a vacuum degree of 1 × 10 ⁻³ Pa, for example. Subsequently, each source gas is supplied into the reaction vessel 402 at a predetermined flow rate by a source gas supply device 404 by a mass flow controller installed in each supply pipe. By adjusting the opening degree of the throttle valve 410 and adjusting the exhaust speed, the internal pressure of the reaction vessel 402 is controlled to a desired pressure. When the internal pressure of the reaction vessel 402 is stabilized, power is supplied from the high-frequency power source 413 to the cathode 414 via the matching box 415, and glow discharge is generated in the reaction vessel 402. With this discharge energy, the source gas introduced into the reaction vessel 402 is decomposed, and a predetermined deposition layer is formed on the cylindrical conductive substrate 401. In order to improve the uniformity of the deposited layer in the circumferential direction of the substrate, a method in which the substrate 401 is rotated at a predetermined speed by the motor 416 via the driving unit 418 during the formation of the deposited layer is effective. The circumferential unevenness of the Si photoconductor can be easily reduced within an allowable range. Thus, when the deposited layer reaches a desired film thickness, the supply of electric power applied to the cathode 414 is stopped, and the supply of the source gas from the source gas supply device 404 is stopped to finish the formation of the deposited layer.

  By repeating the same operation a plurality of times, it becomes possible to form a deposited layer having a multilayer structure.

  The electrophotographic photosensitive member produced by the method as described above can be controlled to have a surface roughness suitable for the present invention by appropriately selecting the production conditions.

“Electrophotographic photoconductor surface polishing apparatus according to the present invention”
In order to obtain the distribution of the surface roughness Ra suitable for the present invention, it is effective to perform a polishing process by an electrophotographic photoreceptor surface polishing apparatus as a post-process after forming the deposited film. According to the polishing treatment, the effects of the present invention can be easily obtained without significantly reducing the photoreceptor characteristics and productivity.

  Hereinafter, an example of an electrophotographic photoreceptor surface polishing apparatus suitable for the present invention will be described in detail.

  FIG. 4 is a schematic configuration diagram showing an example of an electrophotographic photosensitive member surface polishing apparatus. In FIG. 4, 200 is an a-Si photosensitive member, 201 is an elastic support mechanism, specifically a pneumatic holder, and in this experiment, a pneumatic holder manufactured by Bridgestone (product name: air pick, model number: PO45TCA * 820) is used. It was. 203 is a polishing tape, 202 is a pressure elastic roller for winding the polishing tape 203 and pressing it against the a-Si photosensitive member 200, 204 is a delivery roll, 205 is a take-up roll, 206 and 207 are fixed amounts, respectively. It is a feed roll and a capstan roller.

  The pressure elastic roller 202 is formed by forming a rubber 2022 as a flexible member on a cored bar 2021 as shown in FIG. The rubber is made of a material such as neoprene (registered trademark) rubber, silicon rubber, polyurethane rubber, ethylene / propylene rubber, and preferably has a JIS rubber hardness of 20 to 80 and more preferably a JIS rubber hardness of 30 to 60.

  The shape of the pressure elastic roller 202 may be a cylindrical shape whose diameter is uniform in the axial direction, but in order to perform uniform processing in the direction of the photoreceptor bus, the diameter of the central portion is thicker than both ends. The diameter difference is preferably 0.01 to 0.6 mm, more preferably 0.02 to 0.4 mm.

Further, the polishing tape is applied to the rotating photosensitive member 200 while pressing the pressure elastic roller 202 to 49 to 2453 kPa (0.5 to 25 kgf / cm ² ), more preferably 98 to 981 kPa (1 to 10 kgf / cm ² ). 203 is fed to polish the surface of the photoreceptor.

  The rotational speed of the photoconductor may be appropriately adjusted in consideration of the surface properties of the photoconductor and the occurrence of polishing scratches, but is preferably 10 to 500 rpm, and more preferably 20 to 200 rpm.

The abrasive tape 203 is preferably a so-called lapping tape, and the abrasive grains are silicon carbide (SiC), aluminum oxide (Al ₂ O ₃ ), α iron oxide (Fe ₂ O ₃ ), chromium oxide (Cr ₂ O _3). ), Diamond (C), silica (SiO ₂ ), and the like. The grain size of the abrasive grains may be appropriately selected in consideration of the desired surface roughness of the photoreceptor and the polishing time, but is preferably 0.1 to 100 μm, more preferably 1 to 20 μm.

  The polishing tape 203 is a generally well-known coating method, such as a doctor blade (knife edge) coating method, a dip coating method, an air knife coating method, a curtain coating method, a wire bar coating method, a gravure coating method, an extrusion coating method, etc. It is possible to apply by.

  Here, a wrapping tape LT-C2000 (abrasive grains: silicon carbide (SiC), particle diameter: 6 μm, coating method: doctor blade (knife edge) coating method) manufactured by Fuji Photo Film Co., Ltd. was used.

  The feed rate of the polishing tape may be appropriately adjusted in consideration of the surface property of the photoreceptor, the occurrence of polishing flaws, the processing cost, etc., but is preferably 1 to 500 mm / min, and more preferably 10 to 100 mm / min.

  In the present invention, in order to control the distribution of the surface roughness Ra in the range of 10 μm × 10 μm in the direction of the photoreceptor bus, the surface is polished by a pressure elastic roller 202 having an uneven surface as shown in FIG. Carried out.

  FIG. 1 shows a schematic cross-sectional view of a photoconductor schematically showing the surface of the photoconductor obtained at this time. As shown by the arrows in the drawing, the surface area Ra on the surface of the photosensitive member is 10 μm × 10 μm in the range where the surface roughness Ra is small, and the area B is 10 μm × 10 μm in the range where the surface roughness Ra is large.

  In this way, by appropriately adjusting the uneven shape on the surface of the pressure elastic roller 202, the size of the surface roughness Ra in the range of 10 μm × 10 μm of the photoconductor is controlled to a desired distribution, and alternately formed in the bus line direction. be able to.

  Further, even if an uneven shape is provided in the generatrix direction on the surface of the polishing tape 203, the distribution of the surface roughness Ra of the photoreceptor can be controlled similarly. Also in this case, the surface roughness Ra in the range of 10 μm × 10 μm of the photoconductor is controlled to a desired distribution by appropriately adjusting the uneven shape on the surface of the polishing tape 203, and alternately formed in the bus line direction. Can do. The uneven shape on the surface of the polishing tape 203 can be appropriately controlled by devising the coating method described above. For example, an uneven shape can be provided on the surface of the polishing tape 203 by a wire bar coating method.

  Further, a photoconductor may be prepared using a conductive substrate 101 having a concavo-convex shape in advance, and polishing may be performed with a smooth pressure elastic roller 1030 having no concavo-convex shape as shown in FIG.

  FIG. 2 is a schematic cross-sectional view of the photoconductor schematically showing the surface of the photoconductor obtained at this time. As shown by the arrows in the drawing, the surface area Ra on the surface of the photosensitive member is 10 μm × 10 μm in the range where the surface roughness Ra is small and the area B is 10 μm × 10 μm in the range where the surface roughness Ra is large.

  In this case, the size of the surface roughness Ra in the range of 10 μm × 10 μm of the photosensitive member is controlled to a desired distribution by appropriately adjusting the uneven shape provided in advance on the conductive substrate 101, and alternately formed in the bus line direction. Can do. Further, it is preferable to appropriately adjust the JIS rubber hardness of the pressure elastic roller 202.

"Electrophotographic apparatus according to the present invention"
An example of the electrophotographic apparatus of the present invention using the electrophotographic photosensitive member thus produced is shown in FIG. The apparatus of this example is suitable when a cylindrical electrophotographic photosensitive member is used. However, the electrophotographic apparatus of the present invention is not limited to this example, and the shape of the photosensitive member is an endless belt. It may be as desired. The apparatus of this example is a digital electrophotographic apparatus, but may be an analog electrophotographic apparatus.

  In the electrophotographic apparatus 500 of FIG. 8, reference numeral 501 denotes an electrophotographic photosensitive member according to the present invention, and reference numeral 502 denotes a primary charger that charges the photosensitive member 501 for forming an electrostatic latent image. Reference numeral 503 denotes an electrostatic latent image forming means (exposure device). As a light source for exposure E, a halogen light source or a light source mainly having a single wavelength is used. Reference numeral 504 denotes a developing device for supplying developer (toner) to the photosensitive member 501 on which the electrostatic latent image is formed. Reference numeral 505 transfers toner on the surface of the photosensitive member to the transfer material and then separates the transfer material. This is a transfer / separation charger.

  Reference numeral 506 denotes a cleaner that cleans the surface of the photoreceptor. In this example, in order to effectively remove the surface of the photoconductor, the surface of the photoconductor is cleaned using the elastic roller 5061 and the cleaning blade 5062 as described above, but only one of them may be used.

  507 is a static elimination light source for neutralizing the surface of the photosensitive member in preparation for the next copying operation, 510 is a transfer material such as paper, 509 is a registration roller for feeding the transfer material, and 508 is a toner transferred to the transfer material. A fixing device for fixing.

  Using such an apparatus, a copy image is formed as follows, for example. First, the electrophotographic photosensitive member 501 is rotated at a predetermined speed in the direction indicated by the arrow X, and the surface of the photosensitive member 501 is uniformly charged using the primary charger 502. Next, image exposure E is performed on the surface of the charged photoconductor 501 to form an electrostatic latent image of the image on the surface of the photoconductor 501. Then, when the electrostatic latent image on the surface of the photoreceptor 501 is passed through the installation portion of the developing device 504, toner is supplied to the surface of the photoreceptor 501 by the developing device 504, and the electrostatic latent image is The toner image is developed (developed) as an image, and the toner image reaches the installation portion of the transfer / separation charger 505 as the photosensitive member 501 rotates, and is transferred to the transfer material 510 sent by the registration roller 509. It is transcribed.

  After the transfer is completed, residual toner is removed from the surface of the electrophotographic photosensitive member 501 by the cleaner 506 in order to prepare for the next copying process, and further, the charge is removed by the charge removing light source 507 so that the surface potential becomes zero or almost zero. One copy process is completed.

  Hereinafter, the present invention will be described in detail based on examples and comparative examples.

  The following examples are examples of the best mode of the present invention, but the present invention is not limited to these examples.

<Example 1 and Comparative Example 1>
Using the plasma processing apparatus shown in FIG. 7, the charge injection blocking layer, the first and second photoconductive layers, and the surface layer shown in FIG. A positively charged a-Si photoconductor having a diameter of 80 mm was prepared.

  “200 → 20” in the production conditions shown in Table 1 indicates that the gas flow rate is continuously changed from 200 ml / min (normal) to 20 ml / min (normal).

Here, when the Ra of the surface of the produced photoreceptor was measured, Ra was about 45 nm and the entire surface was almost uniform, and this was designated as an electrophotographic photoreceptor No. 101 which does not form Ra.

  Next, the produced a-Si photoconductor was subjected to polishing using the electrophotographic photoconductor surface polishing apparatus shown in FIG. Specifically, using the pressure elastic roller 202 having a concavo-convex shape on the surface shown in FIG. 5 (a), the size of Ra is alternately formed in the generatrix direction as shown in the schematic sectional view of FIG. At the same time, electrophotographic photosensitive members No. 102 to 109 with different Ra large and small intervals L shown in FIG.

  As for the value of Ra, the maximum value is 45 nm and the minimum value is 15 nm.

  In the image evaluation, the image flow was evaluated in a high-temperature and high-humidity environment when the photoconductor heater at night was turned off. Specifically, using Canon's digital electrophotographic device iR-6000 (pre-exposure 660 nm LED array, image exposure 655 nm laser, process speed 265 mm / sec), printing in a high temperature and high humidity environment of 30 ° C and 80% RH An image was output using a test pattern having a printing rate of 1% and a printing rate lower than usual, 25,000 sheets / day, and the photoconductor heater was turned off at night and left overnight. At the start of the next morning, an image was output using a character chart and a halftone chart with a printing ratio of 4%. This paper passing durability test was conducted continuously for 10 days.

Table 2 shows the evaluation results of image flow of the electrophotographic photosensitive members No. 101 to 109. The symbols indicating the evaluation results in Table 2 are as follows:
A: Image flow is not observed in both the character chart and the halftone chart.

〇: In the case of a character chart, image flow is not allowed,
In the case of the halftone chart, a slight image flow is recognized in a part.
△: Image flow is not allowed in the case of a character chart,
In the case of a halftone chart, part of the image flow is recognized.
×: In the case of a character chart, a part of the image flow is recognized,
In the case of a halftone chart, part of the image flow is recognized.
Means.

From the results of Table 2, the image flow is good in the electrophotographic photosensitive members No. 102 to 109 in which Ra is alternately formed in the generatrix direction with respect to the electrophotographic photosensitive member No. 101 in which the size of Ra is not formed. I found out that

  Further, it has been found that the interval at which Ra is alternately formed in the direction of the bus is preferably 10 μm or more and 200 μm or less, more preferably 80 μm or more and 150 μm or less.

<Example 2>
The a-Si photosensitive member produced in the same manner as in Example 1 with the manufacturing conditions shown in Table 1 changed as appropriate is shown in FIG. 6A using the electrophotographic photosensitive member surface polishing apparatus of FIG. In this way, the polishing process was performed with the pressure elastic roller provided with the uneven shape, and the magnitude of Ra was alternately formed in the direction of the bus.

  Here, the electrophotographic photosensitive member No. 201 to 206 is appropriately changed in polishing processing time, and the electrophotographic photosensitive member No. 207 to 211 is appropriately changed in high-frequency power, gas flow rate, and substrate temperature, which are manufacturing conditions of the photoconductive layer. Electrophotographic photosensitive members No. 201 to 211 having different maximum and minimum values of Ra were manufactured. The intervals of Ra are both 120 μm.

  In the image evaluation, cleaning characteristics such as toner fusion and toner abrasion in a low temperature and low humidity environment were evaluated.

  Specifically, using Canon's iR-6000 digital electrophotographic device, image output using a test pattern with a print rate of 1% and a lower print rate than usual in a low-temperature, low-humidity environment of 23 ° C and 5% RH. 25,000 sheets / day, and the photoconductor heater was turned off at night and left overnight. At the start of the next morning, an image was output using a solid white image and a halftone chart. This paper passing durability test was carried out continuously for 10 days, and was evaluated by the presence or absence of black spots on the solid white image and the density unevenness of the halftone image.

  Table 2 shows the evaluation results of toner fusion and toner abrasion of the electrophotographic photosensitive members No. 201 to 211. The symbols indicating the evaluation results in Table 2 mean :: very good, ○: excellent, Δ: no practical problem.

From the results shown in Table 3, it is preferable that the maximum value and the minimum value of Ra are in the range of 5 nm to 100 nm, the minimum value of Ra is 5 nm to 20 nm, and the maximum value of Ra is 30 nm to 100 nm. I found out.

<Example 3>
The a-Si photosensitive member produced in the same manner as in Example 1 was polished with a pressure elastic roller having an uneven shape using an electrophotographic photosensitive member surface polishing apparatus, and the magnitude of Ra was determined as a bus. Alternately formed in the direction.

  However, the distribution of the concavo-convex shape of the pressure elastic roller was changed so that the area ratio of Ra was different. The produced electrophotographic photosensitive members were designated as Nos. 301 to 308. The intervals of Ra are both 120 μm and Ra values are 45 nm maximum and 15 nm minimum, respectively.

  In the image evaluation, the cleaning characteristics such as toner fusion and toner abrasion in a low temperature and low humidity environment were evaluated as in Example 2.

  Table 4 shows the evaluation results of toner fusion and toner abrasion of the electrophotographic photosensitive members No. 301 to 308. The symbols indicating the evaluation results in Table 4 mean ◎: very good, ◯: excellent.

From the results shown in Table 4, it was found that the area ratio of Ra is preferably 20% or more of the whole region of 5 nm to 20 nm and 20% or more of the whole region of 30 nm to 100 nm.

<Example 4 and Comparative Example 2>
An a-Si photosensitive member was produced in the same manner as in Example 1 except that a conductive substrate provided with an uneven shape was used in advance. Here, when Ra of the surface of the produced photoreceptor was measured, Ra was about 45 nm and the entire surface was almost uniform. This was designated as an electrophotographic photoreceptor No. 401 which does not form Ra, and Comparative Example 2 was obtained.

  Next, the electrophotographic photoreceptor surface polishing apparatus shown in FIG. 4 was used for the a-Si photoreceptor produced in the same manner as in Example 1 except that a conductive substrate provided with an uneven shape was used in advance. The polishing process was carried out with a smooth pressure elastic roller 202 without unevenness as shown in FIG. 5B, and as shown in FIG. 2, the magnitude of Ra was alternately formed in the direction of the bus. Here, the uneven shapes provided in advance on the conductive substrate were controlled to produce electrophotographic photosensitive members No. 402 to 404 having different Ra large and small intervals L shown in FIG. As for the value of Ra, the maximum value is 45 nm and the minimum value is 15 nm for all the photoconductors.

  In the image evaluation, as in Example 1, the image flow was evaluated in a high-temperature and high-humidity environment when the photoconductor heater at night was turned off.

Table 5 shows the evaluation results of the image flow of the electrophotographic photosensitive members No. 401 to 404. The symbols indicating the evaluation results in Table 5 are:
A: Image flow is not observed in both the character chart and the halftone chart.
×: In the case of a character chart, a small part of the image flow is recognized,
In the case of a halftone chart, part of the image flow is recognized.
Means.

From the results shown in Table 5, an a-Si photoconductor was prepared using a conductive substrate provided with a concavo-convex shape in advance for the electrophotographic photoconductor No. 401 in which the magnitude of Ra was not formed, and then a polishing process was performed. As a result, it was found that the image flow was remarkably improved in the electrophotographic photosensitive members No. 402 to 404 in which the magnitudes of Ra were alternately formed in the generatrix direction.

1 is a schematic cross-sectional view schematically showing a surface shape in a generatrix direction of an electrophotographic photosensitive member according to the present invention. 1 is a schematic cross-sectional view schematically showing a surface shape in a generatrix direction of an electrophotographic photosensitive member according to the present invention. 1 is a schematic cross-sectional view schematically showing a layer configuration of an electrophotographic photoreceptor according to the present invention. It is a typical block diagram which shows an example of the electrophotographic photoreceptor surface polishing apparatus concerning this invention. It is a typical block diagram which shows an example of the pressure elastic roller used for the electrophotographic photoreceptor surface polishing apparatus concerning this invention. It is a typical block diagram which shows an example of the electrophotographic photoreceptor manufacturing apparatus by RF-PCVD concerning this invention. It is a typical block diagram which shows an example of the electrophotographic photoreceptor manufacturing apparatus by VHF-PCVD concerning this invention. 1 is a schematic configuration diagram showing an example of a digital electrophotographic apparatus equipped with an electrophotographic photosensitive member according to the present invention. It is a figure explaining the measurement conditions in AFM observation concerning the present invention. 3 is an AFM observation image of a 10 μm × 10 μm field showing an example of the surface of the electrophotographic photosensitive member according to the present invention. 3 is an AFM observation image of a 10 μm × 10 μm field showing an example of the surface of the electrophotographic photosensitive member according to the present invention.

Explanation of symbols

100 ... Electrophotographic photoreceptor
103 ... Photoconductive layer
200 ... a-Si photoconductor A ... Part with small surface roughness Ra B ... Part with large surface roughness Ra ... Repeating unit of change in surface roughness Ra

Claims (7)

  In an electrophotographic photosensitive member in which at least an amorphous silicon photoconductive layer is formed on a support, the surface roughness Ra in the range of 10 μm × 10 μm of the photosensitive member is alternately formed in the direction of the generatrix. An electrophotographic photoreceptor.   2. The electrophotographic photosensitive member according to claim 1, wherein the surface roughness Ra in the range of 10 [mu] m * 10 [mu] m of the photosensitive member is alternately formed in the bus line direction at intervals of 10 [mu] m to 200 [mu] m.   2. The electrophotographic photosensitive member according to claim 1, wherein the surface roughness Ra in the range of 10 [mu] m * 10 [mu] m of the photosensitive member is alternately formed in the bus line direction at intervals of 80 [mu] m to 150 [mu] m.   The surface roughness Ra in the range of 10 μm × 10 μm of the photosensitive member is set to a range of 5 nm to 100 nm, and the minimum value of Ra is set to 5 nm to 20 nm and the maximum value of Ra is set to 30 nm to 100 nm. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is provided.   The surface roughness Ra in the range of 10 μm × 10 μm of the photoreceptor is formed so that the area ratio of 5 nm to 20 nm is 20% or more of the entire area, and the area of 30 nm to 100 nm is 20% or more of the entire area. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is provided.   In the photoreceptor, the surface shape of the support has undulations including peaks and valleys in the generatrix direction, and the surface roughness Ra in the range of 10 μm × 10 μm of the photoreceptor is matched to the peaks and valleys of the support. 6. The electron according to claim 1, wherein the electron is formed alternately so that a minimum value of Ra exists in a peak portion of the support and a maximum value of Ra exists in a valley portion of the support. Photoconductor. The electrophotographic process according to any one of claims 1 to 6, wherein the surface of the photoconductor is subjected to a polishing treatment, and the surface roughness Ra of the photoconductor in the range of 10 µm x 10 µm is alternately formed in the direction of the generatrix. Photoconductor.