Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
  • G03G5/142—Inert intermediate layers
  • G03G5/144—Inert intermediate layers comprising inorganic material
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
  • G03G5/082—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and not being incorporated in a bonding material, e.g. vacuum deposited
  • G03G5/08214—Silicon-based
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
  • G03G5/082—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and not being incorporated in a bonding material, e.g. vacuum deposited
  • G03G5/08214—Silicon-based
  • G03G5/08221—Silicon-based comprising one or two silicon based layers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
  • G03G5/082—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and not being incorporated in a bonding material, e.g. vacuum deposited
  • G03G5/08214—Silicon-based
  • G03G5/08235—Silicon-based comprising three or four silicon-based layers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
  • G03G5/082—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and not being incorporated in a bonding material, e.g. vacuum deposited
  • G03G5/08214—Silicon-based
  • G03G5/0825—Silicon-based comprising five or six silicon-based layers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/08—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
  • G03G5/082—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and not being incorporated in a bonding material, e.g. vacuum deposited
  • G03G5/08214—Silicon-based
  • G03G5/08278—Depositing methods

Definitions

• the present invention relates to an electrophotographic photoreceptor that performs image exposure using a laser beam, and in particular, has excellent electric potential characteristics and image quality in an electrophotographic apparatus corresponding to energy saving and high resolution of an image.
• amorphous silicon compensated with hydrogen and / or halogen elements (hereinafter referred to as a-Si) is one of the materials for high-performance, high-durability, and non-polluting electrophotographic photosensitive members used in copiers and laser beam printers. ) Deposited films are used.
• An electrophotographic photoreceptor using an a_Si deposited film includes a charge injection blocking layer having a function of preventing charge injection from a conductive substrate, a photoconductive layer having photoconductivity, and a charge And a surface layer for the purpose of imparting a stopping power and a photosensitive stability.
• the surface layer affects the electrical and optical characteristics, the usage environment characteristics, and the durability of the electrophotographic photoreceptor, and surface layers of various constituent elements and compositions have been proposed so far.
• Japanese Patent Application Laid-Open No. 57-115551 discloses that a non-photoconductive layer is formed on a photoconductive layer composed of an amorphous silicon material mainly composed of silicon and containing at least one of a hydrogen atom and a halogen atom.
• a photoconductive member having a surface layer mainly composed of silicon atoms and carbon atoms and provided with a hydrogen atom-containing amorphous material (a-SiC: H).
• a- S i C Provide a surface layer consisting of H
• 4,675,265) discloses an amorphous silicon material containing an amorphous silicon material containing 10 to 40 atomic% of hydrogen atoms on a photoconductive layer.
• An example of an electrophotographic photosensitive member provided with a surface layer made of carbon (a-C: H) is disclosed. Since a-C: H has a low surface energy, adsorption of low-resistance substances is reduced, and it is possible to suppress a decrease in surface resistance and charge retention ability in a high-humidity environment. The need for a heater for heating is eliminated. However, the a-C: H film easily absorbs image exposure, so that the sensitivity tends to decrease.
• an intermediate layer may be provided between the surface layer and the photoconductive layer for the purpose of improving adhesion, potential characteristics, image quality, and the like.
• Japanese Patent Publication No. 63-035026 discloses that a carbon atom and a hydrogen Electrophotographic photoreceptors having an a-Si intermediate layer containing an element and / or a fluorine atom as a component have been proposed. This makes it possible to reduce cracks and peeling of the photoconductive layer.
• Japanese Patent Application Laid-Open No. 2-203350 (corresponding to US Pat. No. 5,262,263) discloses that an intermediate layer and a surface layer are composed of a-SiC: H. There is disclosed a technique for optimizing the carbon content at the interface with the layer and the carbon content at the interface between the intermediate layer and the surface layer to reduce dark attenuation and improve the surface potential.
• the intermediate layer can also have the effect of improving image quality.
• interference occurs when an electrostatic latent image is formed by image exposure, and image quality is reduced.
• This problem can be improved by providing an intermediate layer.
• JP-A-6-242624 (corresponding to U.S. Pat. No. 5,455,438) states that when a photoconductive layer and a surface layer are formed by plasma CVD, the composition is changed from the photoconductive layer to the surface layer.
• Japanese Patent No. 2674302 (corresponding to U.S. Pat. No.
• 5,162,182 discloses an electrophotographic photoreceptor having a charge transport layer, a charge generation layer, and a surface layer laminated on a conductive substrate.
• An example of an electrophotographic photoreceptor provided with a thick interference control layer is disclosed.
• Means for reducing the spot diameter of the exposure laser beam include exposure Examples include improving the accuracy of an optical system that irradiates the photoconductive layer with laser light, and increasing the aperture ratio of an imaging lens.
• this spot diameter can only be reduced to the diffraction limit determined by the wavelength of the exposure laser beam and the aperture ratio of the imaging lens. Large size—Increase in cost is inevitable.
• the present inventors have studied an electrophotographic photoreceptor having magnesium fluoride as a surface layer, and found that when magnesium fluoride was used as a surface layer on an amorphous silicon layer, a conventionally used surface layer was used. In some cases, it was difficult to obtain the desired potential characteristics, particularly the desired charging ability, sensitivity, and residual potential, as compared with materials. In addition, although metal fluorides such as magnesium fluoride are unlikely to cause image bleeding due to the high humidity environment, it is easy to cause image defects due to image bleeding.
• the photoconductive layer mainly composed of amorphous silicon is easy to control the conditions and is easy to obtain excellent film characteristics, etc., and is based on the glow discharge method, especially the RF band, VHF band or It is often formed by plasma CVD using a power frequency in the W band.
• metal fluorides such as magnesium fluoride are difficult to form by plasma CVD, so that a photoconductive layer is formed by a plasma CVD device, and then, a fluorine film is formed using a sputtering device or a vapor deposition device. It is appropriate to form a surface layer composed of a magnesium oxide film.
• the a-SiC: H film and a-C: H film conventionally used for the surface layer are relatively easy to form by CVD, and are composed of elements that constitute the layer from the photoconductive layer to the surface layer.
• the interference can be prevented by continuously changing the composition ratio to prevent the formation of a clear reflecting surface.
• magnesium fluoride is formed by sputtering or the like. Reflection between the photoconductive layer and the surface layer A surface is easily formed. Therefore, when the incident laser light is easily reflected between the photoconductive layer and the surface layer, such as when the surface roughness of the photoconductive layer is small, the image quality tends to be reduced due to the interference.
• an intermediate layer for suppressing interference can be provided between the photoconductive layer and the magnesium fluoride film.However, excellent potential characteristics and suppression of deterioration in image quality due to interference can be achieved. Materials that are compatible must be properly selected. ⁇
• An object of the present invention is to provide an electrophotographic photoreceptor that has excellent potential characteristics and can suppress a decrease in image quality due to interference in an electrophotographic apparatus that supports energy saving and high image quality. Is to do.
• the present invention provides an electrophotographic photoreceptor having the following configuration. That is, an electrophotographic photoreceptor having at least a photoconductive layer mainly composed of amorphous silicon on a conductive substrate, a surface layer, and at least one intermediate layer between the photoconductive layer and the surface layer.
• the special feature is that the surface layer has a metal fluoride (excluding silicon fluoride) and the intermediate layer has a metal oxide.
• a metal fluoride is used for the surface layer of the electrophotographic photoreceptor, and at least one layer of metal oxide is provided between the photoconductive layer and the surface layer.
• FIG. 1 is a schematic view showing an example of the layer structure of the electrophotographic photosensitive member according to the present invention.
• FIG. 1B is a schematic view showing an example of a layer configuration of the electrophotographic photoreceptor according to the present invention when the intermediate layer has two layers.
• FIG. 2 is a diagram showing an example of the relationship between the thickness of the surface layer and the reflectance.
• FIG. 3 is a plan view of an example of an exposure apparatus that forms an electrostatic latent image on an electrophotographic photosensitive member.
• FIG. 4 is a diagram illustrating an example of the relationship between the incident angle of laser light and the maximum value of the reflectance at that position.
• FIG. 5 is a schematic diagram showing an example of a plasma CVD apparatus for forming a photoconductive thin film containing amorphous silicon as a main component on a cylindrical substrate.
• FIG. 6 is a schematic view showing an example of a sparing apparatus for forming an intermediate layer and a surface layer according to the present invention on a substrate.
• FIG. 1A shows an example of a layer configuration of the electrophotographic photosensitive member according to the present invention.
• An amorphous silicon electrophotographic photoreceptor 1000 shown in FIG. 1A has a conductive substrate 1101 made of aluminum or the like, a charge injection blocking layer 1201, a photoconductive layer 1202, and the like sequentially laminated on the surface of the conductive substrate 1101. It comprises a silicon layer 1200, an intermediate layer 1300, and a surface layer 1401.
• the charge injection blocking layer 1201 has a function of blocking charge injection from the conductive substrate 1101 to the photoconductive layer 1202, and can be provided as necessary.
• the photoconductive layer 1202 is made of a non-single-crystal material including a silicon thick layer, and has photoconductive properties.
• the surface layer 1401 has a function of preventing charge injection from the surface of the electrophotographic photosensitive member 1000 to the photoconductive layer 1202 and / or protects the surface of the photoconductive layer 1202, and has a moisture-resistant property on the electrophotographic photosensitive member 1000. It has the function of imparting repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.
• An intermediate layer 1300 comprising at least one layer is provided between the photoconductive layer 1202 and the surface layer 1401.
• the number of the intermediate layers 1300 may be only one as shown in FIG. 1A, but the absorption of incident laser light is large. Two or more layers (see Fig. 1B) or more layers may be provided as long as the thickness does not decrease.
• metal fluoride excluding silicon fluoride
• Metal fluorides (excluding silicon fluoride) used for the surface layer 1401 include magnesium fluoride (MgF 2 ), lanthanum fluoride (L a F 3 ), barium fluoride (B a F 2 ), and fluoride calcium (C a F 2), and the like aluminum fluoride Niumu (Al F 3) is. Since these metal fluorides have a small surface free energy, by using them as the surface layer 1401, an electrophotographic photoreceptor in which image deletion due to a high-humidity environment is unlikely to occur can be obtained. Further, among these, fluoride having particularly low absorption for light and having suitable hardness as a surface layer
• the present inventors have studied from various angles an electrophotographic photoreceptor using magnesium fluoride for the surface layer 1401, and as a result, when metal fluoride is formed on the photoconductive layer 1202 as the surface layer 1401, it is excellent. In some cases, it was difficult to obtain desired characteristics in terms of potential characteristics, in particular, charging ability, sensitivity, residual potential, and the like. In addition, when the a-SiC: H layer was provided as the intermediate layer 1300, it was sometimes difficult to obtain sufficient charging ability and residual potential. Furthermore, when a metal fluoride is formed as a surface layer 1401 on the photoconductive layer 1202, or when an a-SiC: H film is provided on the intermediate layer 1300, image deletion becomes apparent and image defects occur. There was something easy.
• the present inventors have found that when a magnesium fluoride film is used as the surface layer 1401 of the electrophotographic photoreceptor 1000, excellent potential characteristics, in particular, desired charging ability, sensitivity, residual potential, and resolution can be ensured.
• metal oxides were most suitable.
• the reason why the desired potential characteristics can be obtained by providing the intermediate layer 1300 made of a metal oxide seems to be that film characteristics such as electrical characteristics are unlikely to change even when the metal oxide is exposed to fluorine. It is.
• the metal oxide absorbs only a small amount of light, the sensitivity can be prevented from lowering.
• Is a metal Sani ⁇ used as the intermediate layer 1300 Sani ⁇ aluminum (A1 2 0 3), magnesium oxide (MgO), lanthanum oxide (La 2 0 3), acid Ihichitan (T i 0 2) , zirconium oxide (Z R_ ⁇ 2), silicon oxide (S i 0, Si_ ⁇ 2), and the like.
• these metal fluorides and metal oxides need not be stoichiometric, and may contain oxygen, hydrogen, carbon, nitrogen, etc. Hydrogen, fluorine, carbon, nitrogen and the like may be contained, but in order to obtain a film with low light absorption, the content of these impurities is preferably small.
• the use of metal fluoride (excluding silicon suicide) for the surface layer 1401 and the use of metal oxide for the intermediate layer 1300 suppresses image deletion caused by a high humidity environment. And an electrophotographic photoreceptor having excellent potential characteristics can be obtained. The Further, since the deterioration of the amorphous silicon layer 1200 can be prevented, even when the resolution is increased, it is possible to suppress the appearance of the image deletion.
• the spot diameter when exposure is performed on the photoconductive layer 1202 using a spot-shaped laser beam, the spot diameter can be set to 40 ⁇ or less, and the resolution of an image can be increased.
• an electrostatic latent image can be formed by using a laser beam having an oscillation wavelength of 380 to 450 nm.
• Metal fluorides other than silicon fluoride used for the surface layer 1401 and metal oxides used for the intermediate layer 1300 have a small absorption even for light having a wavelength of 380 to 450 nm, so that they can be used in electrophotographic devices compatible with high resolution. Sensitivity is hard to decrease even if it is installed.
• Other means for reducing the spot diameter of the exposure laser beam include improving the accuracy of the optical system, increasing the aperture ratio of the lens, and the like.
• a main scanning direction in which scanning is performed along the generatrix direction of the electrophotographic photosensitive member 1000 by a rotating polygon mirror or the like, and a sub-scanning direction caused by rotation of the electrophotographic photosensitive member.
• the spot diameter in the present invention may be in any direction and the smaller one is defined. This is because in any direction, the influence of the image flow is more prominent in the direction of the spot diameter where the influence is small.
• the reflectance on the surface of the electrophotographic photoreceptor 1000 can be reduced by adjusting the thickness and the refractive index of the intermediate layer 1300. Reducing the reflectivity causes a change in sensitivity during repeated use of the electrophotographic photoreceptor, uneven sensitivity due to uneven reflectivity in the generatrix direction, and deterioration of image quality due to the appearance of interference fringe patterns. Can be suppressed. This reflectivity varies depending on various factors in the process of repeatedly using the electrophotographic photosensitive member. Therefore, In order to suppress a decrease in image quality, it is necessary to reduce the maximum value of the changing reflectance. The factors that cause the reflectance to fluctuate when the electrophotographic photoreceptor is used repeatedly are described below.
• the first factor is a change in the thickness of the surface layer 1401.
• FIG. 2 shows an example of the relationship between the thickness of the surface layer 1401 and the reflectance.
• the reflectivity changes periodically with a certain fluctuation range. This is because the optical film thickness of the surface layer 1401 changes with the wear of the surface layer 1401.
• the incident laser is perpendicularly incident on the photoconductive layer
• the reflection relative to the wear amount of the surface layer The period of the rate change corresponds to the thickness difference of the surface layer 1401 such that the optical phase difference changes by ⁇ radian
• the value A d (nm) is expressed by the following equation.
• ⁇ represents the wavelength (nm) of the exposure laser light
• n SL represents the refractive index of the surface layer 1401.
• the electrophotographic photoreceptor 1000 As the electrophotographic photoreceptor 1000 is repeatedly used, the fluctuation of the amount of light incident on the photoconductive layer 1202 increases. Therefore, the fluctuation range of the sensitivity due to the abrasion of the surface layer 1401 becomes large, and a constant image density cannot be obtained when the photoconductor is repeatedly used. Therefore, R. It is necessary to adjust the thickness and the refractive index of the intermediate layer 1300 so as to reduce the value of.
• FIG. 3 is a plan view of an example of an exposure apparatus that forms an electrostatic latent image on an electrophotographic photosensitive member.
• an image exposure apparatus comprises a laser diode 4001, a rotating polygon mirror 4002, and a lens 4003.
• a laser beam emitted from a laser diode 4001 is deflected by a rotating polygon mirror 4002 and is charged to a predetermined potential through a lens 4003. Scanning is performed on the true photoconductor 1000 to form an electrostatic latent image.
• the laser beam is vertically incident near the center of the electrophotographic photosensitive member, and as the position shifts from the center, the incident angle 0 in the main scanning direction changes within a range of ⁇ 10 ° to 20 ° on soil.
• scanning is performed on an electrophotographic photosensitive member.
• Figure 4 shows the incident angle of the laser beam and R. An example of the relationship with is shown. In FIG. 4, a large angle of incidence of, i.e., the reflectance in the vicinity of the end portion of the electrophotographic photosensitive member has a maximum (R "ax) ToNatsu.
• the electrophotographic light body Irregularities of the reflectance may increase along the generatrix direction If the irregularities of the reflectivity increase, the amount of light incident on the photoconductive layer 1202 along the generatrix direction may vary, resulting in uneven sensitivity and, consequently, image quality. Also, when the value of R max is large, interference fringes tend to appear, which may appear in an image and degrade the image quality, so that even if the angle of the laser beam changes, It is necessary to adjust the film thickness and the refractive index of the intermediate layer 1300 so that the maximum value of the reflectance of the electronic photoconductor in the image forming range can be kept low.
• the maximum value R raax of the reflectivity is 20% or less.
• the optical scanning When the surface of the photoconductive layer 1202 is exposed while changing the incident angle of the exposure laser beam using an inspection device, the film thickness of the surface layer 1401 changes, and the change varies according to the incident angle of the exposure laser beam.
• the thickness of the intermediate layer 1300 and the refractive index so that the maximum value of the reflected light is 20% or less, the sensitivity fluctuation due to the wear of the surface layer 1401 and the bus of the electrophotographic photosensitive member It is possible to suppress sensitivity unevenness in the direction and reflection of interference fringes on the image.
• the refractive index and film thickness of the intermediate layer 1300 can be arbitrarily adjusted so that the maximum value of the reflectance is 20% or less.
• the thickness of the intermediate layer may be adjusted so as to be a phase difference, that is, an odd multiple of ⁇ radian. This means that the components reflected at the interface between the surface layer 1401 and the intermediate layer 1300 and reaching the interface between the intermediate layer 1300 and the photoconductive layer 1202, and the components reflected at the interface between the intermediate layer 1300 and the photoconductive layer 1202. If the phase difference is ⁇ , it is expressed by the following equation (1).
• k is a positive integer.
• the thickness unevenness of the intermediate layer 1300 is desirably as small as possible, but if the optical phase difference of the intermediate layer 1300 is within a range where the optical phase difference does not fluctuate greatly, the influence on the reflectance unevenness can be reduced. it can.
• the thickness of the intermediate layer may be constant in the generatrix direction of the electrophotographic photoreceptor, but at the position in the generatrix direction corresponding to each incident angle, the interface between the surface layer 1401 and the intermediate layer 1300 The component reflected and reaching the interface between the intermediate layer 1300 and the photoconductive layer 1202 and the component reflected at the interface between the intermediate layer 1300 and the photoconductive layer 1202 cancel each other out.
• the distribution of the film thickness of the intermediate layer 1300 may be provided over a period of time.
• the condition of the thickness of the intermediate layer 1300 that satisfies the expression (1) is determined according to the number of the intermediate layers 1300 and the magnitude relationship between the refractive indices of the photoconductive layer 1202 and the surface layer 1401. For example, when the intermediate layer 1300 is a single layer, by controlling the thickness d (nni) of the intermediate layer 1300 so as to satisfy the following equations (2) and (3), the incident light can be transmitted to the photoconductive layer 1202.
• the phase difference between the component reflected at the interface between the intermediate layer 1300 and the component reflected at the interface between the intermediate layer 1300 and the surface layer 1401 can be set to an odd multiple of ⁇ radian.
• lambda is the wavelength of the exposure laser (nm)
• n is the refractive index of the intermediate layer 1300
• r ⁇ is the refractive index of the surface layer 1401
• eta [rho represents the refractive index of the photoconductive layer 1202.
• the optical film thickness of the intermediate layer 1300 By adjusting the optical film thickness of the intermediate layer 1300 to be an odd multiple of 1/4 wavelength of the exposure laser as shown in the equation (2), the laser light was perpendicularly incident on the photoconductive layer 1202.
• the phase difference can be such that the component reflected at the interface between the surface layer 1401 and the intermediate layer 1300 and the component reflected at the interface between the intermediate layer 1300 and the photoconductive layer 1202 cancel each other.
• the value of m in equation (2) must be in the range of 1 to 5 in order to make the phase difference such that the value of k in equation (1) falls within the range of 1 to 5.
• the film thickness unevenness of the intermediate layer 1301 is as small as possible, but the film thickness unevenness within a range where the optical phase difference of the intermediate layer 1301 does not largely fluctuate. If so, the effect on the unevenness of the reflectance can be reduced. For example, if the optical phase difference of the intermediate layer 1301 is within ⁇ / 8 radians of earth, that is, if the unevenness is within the range of about ⁇ ⁇ / 16 ⁇ from the film thickness in the equation (2), the film thickness unevenness is caused. The effect of uneven reflectance can be sufficiently suppressed. Therefore, in the present invention, the range of the film thickness unevenness in the range of the soil thickness / 16 ⁇ from the film thickness value satisfying the expression (1) is also included.
• the maximum value of reflectance; nax can be reduced by adjusting the thickness of the intermediate layer 1300 so as to satisfy the expression (1). It is possible to further reduce the maximum value of the reflectance by providing the antireflection ability. In other words, the phase difference is such that the component of the incident laser light reflected at the interface between the surface layer 1401 and the intermediate layer 1300 and the component reflected at the interface between the intermediate layer 1300 and the photoconductive layer 1202 and reaching the surface layer 1401 cancel each other. And by making their intensities equal, it is possible to further reduce the value of R max .
• the refractive index of the intermediate layer 1300 is adjusted. For example, when the intermediate layer 1300 is a single layer, the intermediate layer 1300 has an antireflection function by controlling the refractive index n of the intermediate layer 1300 so as to satisfy the following expression in addition to the expression (2). Can be.
• n is the refractive index of the intermediate layer
• eta [rho is the refractive index of the photoconductive layer
• n S L represents the refractive index of the surface layer.
• FIG. 1B shows an example in which the intermediate layer 1300 has two layers.
• the intermediate layer 1300 includes a first intermediate layer 1301 in contact with the photoconductive layer 1202, and a second intermediate layer 1302 in contact with the surface layer 1401.
• the maximum value of the reflectance can be suppressed to 20% or less by adjusting the thickness and the refractive index of each of the first intermediate layer 1301 and the second intermediate layer 1302.
• the intermediate layer 1300 is a single layer
• the thickness (nm) of the first intermediate layer 1301 in contact with the photoconductive layer and the thickness d 2 (nm) of the second intermediate layer 1302 in contact with the surface layer 1401 ) Is adjusted.
• the order in which the incident light is reflected at the interface between the photoconductive layer 1202 and the first intermediate layer 1301 and reaches the surface layer 1401, and the component reflected at the interface between the second intermediate layer 1302 and the surface layer 1401 is
• An example of the conditions of the thickness of the first intermediate layer 1301 and the second intermediate layer 1302 that can make the phase difference an odd multiple of ⁇ radian is shown below.
• n 2 represents the refractive index of the second intermediate layer 1302
• m and m 2 each represent a positive integer.
• the maximum value of the reflectance can be further reduced by adjusting the refractive index of each of the intermediate layers 1300 so that the intermediate layer 1300 has antireflection ability.
• the intermediate layer 1300 is composed of two layers, the refractive indexes of the first intermediate layer 1301 and the second intermediate layer 1302 must be controlled so as to satisfy the following expression in addition to the expressions (6) and (7).
• the intermediate layer 1300 can have antireflection ability.
• each intermediate layer be made thin so that the value of k in the expression (1) is in the range of 1 to 5.
• the reflectance can be reduced even when the intermediate layer 1300 is provided in a plurality of layers.However, stacking the plurality of layers reduces the manufacturing efficiency and increases the absorption of incident laser light. In some cases, the optical design such as film thickness control may be complicated, so it is preferable that the intermediate layer has only one layer.
• the part mainly composed of amorphous silicon is formed by a deposition method such as glow discharge method (DC or AC CVD method), sputtering method, vacuum evaporation method, ion plating method, optical CVD, and thermal CVD method.
• a deposition method such as glow discharge method (DC or AC CVD method), sputtering method, vacuum evaporation method, ion plating method, optical CVD, and thermal CVD method.
• DC or AC CVD method glow discharge method
• sputtering method sputtering method
• vacuum evaporation method vacuum evaporation method
• ion plating method ion plating method
• optical CVD optical CVD
• thermal CVD method thermal CVD
• FIG. 5 shows an example of an apparatus for forming an amorphous silicon layer 1200 by plasma CVD.
• the reaction vessel 2100 includes a force sword electrode 2101 also serving as an electrode for supplying high frequency power, and a ceramic insulator 2102 for insulating the force sword electrode 2101.
• a substrate holder 2103 for holding the substrate 1101 is provided in the reaction vessel 2100, and a heater 2104 for heating the substrate 1101 to a desired temperature is provided inside the substrate 1101.
• a cap 2105 is provided on the base 1101 so that the heater 2104 is not exposed to plasma.
• the reaction vessel 2100 can be vacuum-sealed by an upper lid 2106.
• a matching box 2107 is connected to the force source electrode 2101, and the matching box 2107 is connected to a high frequency power supply 2108. It is preferable to provide a high frequency shield (not shown) around the force source electrode 2101 to prevent high frequency leakage to the surroundings.
• An exhaust port 2109 is provided at the bottom of the reaction vessel 2101, and an exhaust device 2201 is connected through an exhaust path 2301 and a valve 2501. In the exhaust path 2301, a pressure gauge 2110 for knowing the pressure in the container is provided.
• a gas introduction pipe 2111 arranged concentrically with the base 1101 in the reaction vessel 2100 is connected to a gas supply device 2400 via a gas supply path 2: 302 and a valve 2502.
• the gas supply device 2400 includes gas cylinders 2411, 2421, 2431, 2441, 2451, valves 2511 to 2513, 2521 to 2523, 2531 to 2533, 2541 to 2543, 2551 to 2553, and regulators 2412, 2422, 2432, 2442, 2452. , Mass flow controllers 2413, 2423, 2433, 2443, 2453 and the like.
• the S i feed gas used during formation of the amorphous silicon layer S i H 4, S i 2 H 6, S i 3 H 8, S ⁇ H ⁇ .
• silicon hydrides (silanes) that can be gasified, and SiH 4 and Si 2 H 6 are particularly good in terms of ease of handling during layer formation and high Si supply efficiency.
• a source gas for supplying a halogen gas may be used to positively introduce halogen into the photoconductive layer.
• Haguchi Gengas examples thereof include a halogen compound and an interhalogen compound containing halogen. These can be used alone or diluted with hydrogen or a rare gas.
• a gas containing a conductivity controlling substance such as Group 13 of the periodic table can be supplied for adjusting the conductivity.
• a conductivity controlling substance such as Group 13 of the periodic table
• B 2 H 6 , B 4H! Borohydride and the like, BF 3, and halogenated boron, such as BC l 3 is like et be.
• Other A1 C 1 3, GaC l 3 , InC l 3 , and the like can also be mentioned.
• a conductivity control substance of Group 15 of the periodic table represented by pH 3 or P 2 H 4 can be used.
• the gas may be diluted with a rare gas such as H 2 and / or He as necessary.
• an intermediate layer 1300 and a surface layer 1401 are formed.
• a glow discharge method such as a DC or AC CVD method
• a sputtering method a vacuum deposition method
• an ion plating method It can be formed by a deposited film forming method such as photo CVD, thermal CVD, or the like.
• the intermediate layer 1300 having a function of controlling the reflectance a sputtering method in which uniformity of the film thickness is relatively easy is preferable. Furthermore, considering the versatility of the material and the ease of controlling the conditions, it is desirable that the surface layer be formed by sputtering.
• FIG. 6 is a schematic diagram of an example of a sputtering apparatus for forming the intermediate layer 1300 and the surface layer 1401 of the electrophotographic photosensitive member according to the present invention.
• the metal processing vessel 3101 in which a deposited film is formed is connected via a gas exhaust unit for evacuating the inside of the processing vessel 3101 and a S exhaust path 3301.
• the pressure inside the processing container 3101 can be known by a pressure gauge 3102.
• an opening lock chamber 3103 for carrying in and out the cylindrical base 1101 is provided via a transfer path 3302. Connected. .
• the load lock chamber 3103, an exhaust system 3 202 for evacuating the load lock chamber 3103 is connected via an exhaust passage 3:30 4.
• a pressure gauge 3104 is provided in the load port chamber 3103, and an elevating machine (not shown) for loading and unloading between the processing vessel 3101 and the load port chamber 3103 with the base 1101 supported by the base holder 3105. (Shown) is attached.
• the base is loaded and unloaded through a loading / unloading door 3106 provided in the load lock chamber 3103.
• a rotating shaft 3107 is provided in the processing container 3101, and the base 1101 can be rotated by driving a rotating motor 3108.
• the body 1101 is grounded via the base holder 3105, the rotating shaft 3107, the grounding member 3109, and the processing vessel 3101.
• a cap 3110 is provided on the upper portion of the base 1101 to prevent a deposited film from being formed inside the base 1101.
• a heater (not shown) may be provided in the base holder 3105 so that the base 1101 can be heated.
• a gas supply device 3400 is connected to the processing vessel 3101 via a gas supply path 3303, so that a sputtering gas or a reaction gas can be introduced from a gas introduction nozzle 3111.
• the gas supply device 3400 is composed of gas cylinders 3411, 3421, 3431, valves 3511 to 3513, 3521 to 3523, 3531 to 3533, regulators 3412, 3422, 3432, mass flow controllers 3413, 3423, 3433, and the like.
• a sputtering gas As a sputtering gas, an inert gas such as Ar, He, or Xe is used. Further, a fluorine (F 2 ) gas, an oxygen (O 2 ) gas, or the like is used as a reaction gas, and is appropriately selected according to a desired material of the deposited film. Note that the sputtering gas and the reaction gas may be supplied from different nozzles.
• a target unit 3600 is arranged at a position facing the base 1101.
• the target 3600 is mainly composed of a target 3611, which is a sputtering material, a target holder 3621 for holding the target, an insulator 3631 for insulating the target 3611 from the processing vessel 3101, a magnet 3641, and connection ports 3651 and 3652 for the power supply. And held in a processing vessel 3101 by a shaft 3112.
• Target 3611 The size of the film is optimized according to the length of the substrate 1101 and the size of the processing vessel 3101. The desired film thickness distribution and film characteristics can be obtained by erosion of the sputtering surface 3612 and accompanying thermal deformation. It can be used repeatedly until no more.
• the shape of the target 3611 a flat plate shape or a cylindrical shape can be used.
• the material of the target 3611 is selected according to the type of the deposited film, for example, a conductive material such as Mg, Al, La, Ca, Ba, an alloy having a predetermined composition, or a reaction product of these metals.
• An insulating material such as magnesium fluoride, lanthanum fluoride, calcium fluoride, aluminum fluoride, magnesium oxide, lanthanum oxide, titanium oxide, aluminum oxide, and silicon oxide is used.
• a magnet 3641 is provided on a side opposite to the sputtering surface 3612 so that a magnetic field parallel to the sputtering surface 3612 can be applied.
• a magnetic field By application of a magnetic field, high-density plasma is generated in the vicinity of the sputtering surface 3612, so that the number of sputtered particles increases and the formation speed of a deposited film can be increased.
• the intensity of the magnetic field is adjusted according to the conditions such as the deposition film formation speed.
• a cooling pipe (not shown) is provided in the vicinity of the target 3611 and the magnet 3641.
• the target 3611 and the magnet 3641 may be cooled by disposing a cooling water.
• the target 3611 and the magnet 3641 are held by an insulator 3631 provided in the target holder 3621 and are insulated from the processing container 3101.
• the target holder 3621 is connected to a moving element 3116 via a shaft 3112.
• the moving element 3116 can move along the generatrix direction of the base 1101 by a motor 3113. In this way, by performing sputtering while moving the target 3611, it is possible to reduce the unevenness of the B thickness.
• a means for moving the target 3611 other than the motor an air cylinder or the like may be used.
• the gas is introduced into the gas introduction path 3303.
• the gas introduction path 3303 is made elastic by providing a rose 3117, and the gas introduction X / V 3111 can also be moved in the generatrix direction of the base 1101 by the motor 3113. If there is a possibility that the film properties and adhesion may be reduced due to sputtered particles obliquely incident on the surface on which the deposited film is formed, a collimator (not shown) is provided between the base 1101 and the target 3611, and the sputtering is performed. Particles may be prevented from entering obliquely.
• the electrophotographic photosensitive member when forming the electrophotographic photosensitive member according to the present invention, different target materials may be used when forming the intermediate layer 1300 and the surface layer 1401.
• the processing vessel 3101 ' is opened to the atmosphere and the target 3611 is replaced every time a target layer is formed, the production efficiency may be reduced or impurities may be mixed. Therefore, it is preferable to form the intermediate layer 1300 and the surface layer 1401 without opening the processing container 3101 to the atmosphere.
• a plurality of targets are mounted on a target holder 3621, and the shaft 3112 is rotated. A configuration in which sputtering can be performed while being held at an opposing position is exemplified.
• the target 3611 is provided with a connection port 3651 to the power supply, from which it can be connected to the power supply 3115 via the connection port 3652 and the power cable 3114.
• An electric field can be applied by a power source 3115 using the target 3611 as a cathode and the processing vessel 3101 as an anode.
• a DC power supply is shown in the drawing assuming that the target 3611 is made of a conductive material such as a metal, a high-frequency power supply can be used instead of the DC power supply when the target 3611 is an insulating material.
• the sputtering apparatus shown in FIG. 6 arranges the base 1101 vertically and moves the target 3611 in the vertical direction, but arranges the base 1101 horizontally and moves the target 3611 in the horizontal direction. Is also good.
• the position of the base 1101 is fixed, and the target 3611 is aligned with the axis of the base.
• any of the moving means may be provided. It is also possible to provide a moving means such as a motor or an air cylinder on both the base 1101 and the target 3611, and perform sputtering while moving each other.
• the steps for forming an electrophotographic photosensitive member using the apparatus shown in FIGS. 5 and 6 will be described below.
• a process of forming the amorphous silicon layer 1200 on the base 1101 using the plasma CVD apparatus shown in FIG. 5 will be described below.
• the base 1101 is put into the reaction vessel 2100 and sealed with the upper lid 2106.
• the exhaust device 2201 is operated, the valve 2501 is opened, and the inside of the reaction vessel 2100 is evacuated.
• (1) a processing gas is introduced into the reaction vessel 2100 while controlling the flow rate of the gas used for forming the deposited film by the mass flow controllers 2413, 2423, 2433, 2443, and 2453.
• the processing gas to be used is selected according to the intended function and film characteristics, and the flow rate of the processing gas is adjusted according to the processing conditions.
• high frequency power is applied to the electrode 2101 from the high-frequency power supply 2108 via the matching box 2107, and the processing gas is converted into a positive and negative gas to form an amorphous silicon layer on the base 1101. Form 1200.
• the temperature of the base 1101 may be appropriately adjusted by the heater 2104.
• the pressure inside the reaction vessel 2100 can be adjusted using the throttle valve 2503.
• the leak valve 2504 is opened, the inside of the reaction vessel 2100 is opened to the atmosphere, and the substrate 1101 is taken out.
• the intermediate layer 1300 and the surface layer 1401 are formed by using the sputtering apparatus shown in FIG.
• the step of forming the intermediate layer 1300 and the surface layer 1401 using the sputtering apparatus shown in FIG. 6 is performed as follows.
• a description will be given of a process of forming a deposited film when sputtering is performed by supplying DC power to a metal target.
• the exhaust device 3202 is operated, the valve 3501 is opened, and the load lock chamber 3103 is evacuated.
• Pre-sputtering can be performed as follows. First, the exhaust device 3201 is operated, the valve 3502 is opened, and the inside of the processing container 3101 is evacuated. When the inside of the processing container 3101 reaches a predetermined pressure, The sputtering gas is introduced into the processing vessel 3101 while adjusting the flow rate by the mass flow controller 3413.
• the valve 3501 is closed, the valve 3505 is opened, and the substrate 1101 is transferred into the processing container 3101 and held on the rotating shaft 3107.
• the valve 3504 in the gas supply path 3303 is opened, and a sputtering gas or a reactive gas used for forming a deposited film is introduced into the processing vessel 3101 while controlling the flow rate by the mass flow controllers 3413, 3423, and 3433. At this time, even if the reaction gas is diluted with hydrogen gas or an inert gas, Good.
• DC power is supplied from the DC power source 3115 to the target 3611 to generate plasma.
• the pressure in the processing vessel 3101 be adjusted to a predetermined value by using the throttle valve 3503 in the exhaust path 3301 during the charging.
• Sputtered particles sputtered by the plasma react with a reaction gas on the substrate 1101 to form a deposited film.
• the target moving motor 3113 is driven to move the target 3611 along the generatrix direction of the base 1101.
• the moving speed of the target 3611 and the number of times of reciprocation are arbitrarily adjusted according to the formation conditions such as the formation time of the deposited film.
• the moving range of the target 3611 is adjusted according to the allowable thickness unevenness, but it is preferable to move the target 3611 within a range longer than the base 1101.
• unevenness in film thickness along the outer peripheral direction of the base 1101 can be reduced.
• the valve 3504 and the valve connected to the sputtering gas and reaction gas cylinders are closed to stop gas introduction, and supply of DC power to the target 3611 is stopped. I do.
• a target used for forming the second intermediate layer 1302 or the surface layer 1401 is sputtered in the same procedure to form the intermediate layer 1302 or the surface layer 1401 on the base 1101.
• the substrate 1101 is once transferred to the load log chamber 3103, and a target used for forming the second intermediate layer 1302 or the surface layer 1401 is pre-sputtered, and the regenerated substrate 1101 is processed.
• the inside of the processing container 3301 and the piping of the gas supply device 3400 are purged. Thereafter, the base 1101 is carried out to the load lock chamber 3103, and after opening the leak valve 3506 to return the load lock chamber 3103 to the atmospheric pressure, it is taken out to the atmosphere.
• amorphous silicon layer was formed using the CVD apparatus shown in Fig. 5
• an intermediate layer made of metal oxide and a surface layer made of metal fluoride were formed using the sputtering apparatus shown in Fig. 6, and electrophotography was performed.
• a photoreceptor was fabricated and its potential characteristics were evaluated.
• a charge injection blocking layer mainly composed of amorphous silicon and a photoconductive layer were formed using the CVD apparatus shown in FIG.
• An aluminum cylinder 80 mm in diameter and 358 mm in length was used as a substrate.
• Table 1 shows the conditions for forming the amorphous silicon layer.
• the power supply used had a frequency of 13.56 MHz.
• an intermediate layer made of magnesium oxide was formed to a thickness of 150 nm by using the sputtering apparatus shown in FIG. 6, and a surface layer made of magnesium fluoride was formed thereon to a thickness of 800 nm.
• Magnesium oxide and fluoride Table 2 shows the conditions for forming magnesium.
• the obtained electrophotographic photosensitive member was mounted on a digital copying machine (a modified model of iR6000 manufactured by Canon Inc.), and the potential characteristics were measured by the following procedure. Then, the obtained electrophotographic photoreceptor is installed in a copying machine, and a high voltage of +6 kV is applied to the charger to perform corona charging, thereby charging the surface of the dark portion of the drum measured by a surface electrometer. Noh. In addition, the electrophotographic photoreceptor was charged so that the surface potential of the dark portion became 450 V, and then irradiated with exposure laser light, and the amount of light at which the surface potential became 200 V was measured as sensitivity.
• a digital copying machine a modified model of iR6000 manufactured by Canon Inc.
• the obtained electrophotographic photoreceptor is charged to a dark area surface potential of 450 V at the developing position, and laser light is irradiated at a light intensity of 2 lux ⁇ sec.
• the light area surface potential of the drum at this time remains.
• the wavelength of the exposure laser beam was 660 nm.
• an image was output using the character chart on the white background, and the presence or absence of image flow was examined.
• the image output environment was 30 ° C and 80% RH.
• the spot diameter of the exposure laser light was about 60 ⁇ about 65 ⁇ (spot diameter in the main scanning direction X spot diameter in the sub-scanning direction).
• the light source of the exposure laser light was replaced with a semiconductor laser having a main oscillation wavelength of 405 nm, and an image was output using a character chart on the entire white background, and the presence or absence of image deletion was investigated.
• the spot diameter of the exposure laser beam was about 30 ⁇ about 40 ⁇ (spot diameter in the main scanning direction X spot diameter in the sub scanning direction).
• Example 1 The same substrate as in Example 1 was used, and the procedure and conditions for forming the charge injection blocking layer and the photoconductive layer were the same as in Example 1.
• a surface layer made of magnesium fluoride was formed to a thickness of 800 nm using a sputtering apparatus shown in FIG.
• the conditions for forming the magnesium fluoride film were the same as in Example 1.
• the surface layer made of metal fluoride is formed using the sputtering apparatus shown in Fig. 6.
• the electrophotographic photoreceptor was fabricated by the formation, and its electric potential characteristics were evaluated.
• Example 2 The same substrate as in Example 1 was used, and the procedure and conditions for forming the charge injection blocking layer and the photoconductive layer were the same as in Example 1. After forming the charge injection blocking layer and the photoconductive layer, an intermediate layer composed of a-SiC: H was formed. Table 3 shows the conditions for forming the a-SiC: H intermediate layer.
• a surface layer made of magnesium fluoride was formed to a thickness of 800 nm using the sputtering apparatus shown in FIG.
• the conditions for forming the surface layer were the same as in Example 1.
• Exposure laser beam spot diameter is about 60 ⁇ At m, no image deletion was observed in Example 1 and Comparative Examples 1 and 2. On the other hand, when the spot diameter was reduced to about 30 ⁇ . By setting the wavelength of the exposure laser light to .405 nm, when the intermediate layer made of a metal oxide was provided in Example 1, the image flow did not appear. However, when the magnesium fluoride was formed directly on the amorphous silicon layer in Comparative Example 1, the image deletion was slightly noticeable. In other words, even when the resolution was increased, the image deletion could be effectively suppressed by providing the metal oxide in the intermediate layer. In Comparative Example 2, when the spot diameter of the exposure laser beam was set to about 35 ⁇ , an image that could be evaluated could not be output.
• magnesium oxide was used for the intermediate layer.
• an intermediate layer made of other metal oxides such as aluminum oxide, titanium oxide, and lanthanum oxide was provided, the potential characteristics were good.
• V It is possible to obtain an electrophotographic photoreceptor that does not easily cause an image flow due to a lateral flow of electric charges.
• an intermediate layer made of metal oxide and a surface layer made of metal fluoride were formed using the sputtering apparatus shown in FIG.
• An electrophotographic photoreceptor with a maximum reflectivity of 20% or less was prepared.Evaluation of the initial potential characteristics, image evaluation in a print durability test, sensitivity unevenness and sensitivity fluctuation range, and reflectance The maximum value was evaluated.
• an electrophotographic photoreceptor was manufactured in the same procedure as in Example 1, and the thicknesses of the intermediate layer and the surface layer were the same as in Example 1.
• the constituent materials used for the photoconductive layer, the intermediate layer, and the surface layer were separately formed on a glass substrate (7059 glass substrate manufactured by Corning), and an ultraviolet spectrophotometer (JASCO Corporation) was used.
• the value of the refractive index was measured using V-570) manufactured by Co., Ltd.
• Table 5 summarizes the refractive indices. (Table 5)
• the obtained electrophotographic photosensitive member was attached to a digital copying machine (a modified model of iR6000 manufactured by Canon Inc.), and the following potential characteristics were measured and a printing durability test was performed.
• the copier was equipped with a semiconductor laser emitting a main oscillation wavelength of 405 nm as a light source for forming an electrostatic latent image.
• the spot diameter of the exposure laser beam was about 30 ⁇ 40 ⁇ (spot diameter in the main scanning direction X spot diameter in the sub scanning direction).
• the incident angle of the exposure laser beam in the main scanning direction was varied within a range of 0 ° at the center of the electrophotographic photosensitive member and about 16 ° at the end of the image to perform image exposure.
• a modification was made to change the cleaning roller member from a magnet roller to a polyurethane rubber sponge roller, and a durability test was conducted under conditions that promoted abrasion of the surface layer.
• the charging ability, sensitivity, and residual potential of the obtained electrophotographic photoreceptor were measured in the same procedure as in Example 1. After that, a print durability test was performed, in which the unevenness of sensitivity, the fluctuation range of sensitivity, and the maximum value of reflectance were measured. During the endurance test, the evaluation was performed under the condition that the heater inside the electrophotographic photosensitive body originally mounted on the copying machine was not operated.
• Sensitivity was measured every 30 mm from the center of the electrophotographic photoreceptor in the generatrix direction, and the ratio of the worst part to the best part was calculated as sensitivity unevenness.
• the sensitivity was measured every 20,000 sheets of the print durability test, and the largest sensitivity unevenness was evaluated as the maximum value of the sensitivity unevenness through the print durability test.
• the ratio of the lowest sensitivity to the highest sensitivity through the endurance test was calculated and evaluated as the sensitivity fluctuation range.
• the reflectance to light having a wavelength of 405 nm was measured using a reflection spectroscopic interferometer (MC PD 3000 manufactured by Otsuka Electronics Co., Ltd.).
• the reflectance was measured such that the position of the electrophotographic photosensitive member in the generatrix direction in the copying machine corresponded to the incident angle of the laser beam.
• the reflectivity was measured before the endurance test and every 50,000 sheets in the endurance test at the position in the generatrix direction corresponding to every 1 ° of the incident angle of the laser beam, and the maximum value of the reflectivity was investigated.
• a surface layer made of magnesium fluoride was formed using the sputtering apparatus shown in Fig. 6, and an electrophotographic photoreceptor was fabricated.
• image evaluation was performed in a print durability test, and the sensitivity variation and sensitivity fluctuation range, and the maximum value of reflectance were evaluated. .
• a surface layer made of magnesium fluoride was formed directly on the photoconductive layer in the same procedure as in Comparative Example 1 to produce an electrophotographic photosensitive member, and the same method as in Example 2 was used.
• the initial potential characteristics of the obtained electrophotographic photoreceptor, the sensitivity variation in the print durability test, the fluctuation range of the sensitivity, the appearance of interference fringe patterns, and the maximum reflectance were evaluated. . '
• Example 2 the ratio of the initial charging ability, sensitivity and residual potential, the variation in sensitivity during the endurance test and the fluctuation range of sensitivity, and the reflection fringe pattern were calculated, as compared with Comparative Example 3.
• ⁇ 20% or more improvement over Comparative Example 3
• Table 6 summarizes the results of these evaluations and the maximum values of the reflectance in each experiment.
• the intermediate layer made of magnesium oxide is placed between the surface layer made of magnesium fluoride and the photoconductive layer so that the maximum value of the reflectance is 20% or less.
• the layer was formed, better potential characteristics could be obtained than when the magnesium fluoride film was formed directly on the photoconductive layer in Comparative Example 3.In addition, interference fringes were reflected. It turns out that it is suppressed. Further, it is clear that the sensitivity unevenness and the fluctuation range of the sensitivity are good, and that an electrophotographic photoreceptor with high image quality can be obtained.
• magnesium oxide was used for the intermediate layer.
• an intermediate layer made of magnesium oxide having a different film thickness from that of Example 2 was formed using the sputtering apparatus shown in FIG. Table consisting of magnesium oxide
• An electrophotographic photoreceptor is manufactured by forming a surface layer, and the initial potential characteristics are evaluated, the image is evaluated in a printing durability test, the sensitivity unevenness and the fluctuation range of the sensitivity, and the maximum value of the reflectance is evaluated.
• Example 1 The same substrate as in Example 1 was used, and the procedure and conditions for forming the charge injection blocking layer and the photoconductive layer were the same as in Example 1.
• an intermediate layer made of magnesium oxide and a surface layer made of magnesium fluoride were formed using the sputtering apparatus shown in FIG.
• the conditions for forming the intermediate layer and the surface layer were the same as in Example 1.
• Table 7 shows the combinations of the thicknesses of the magnesium oxide film and the magnesium fluoride film in each comparative example.
• the obtained electrophotographic photoreceptor was subjected to the same method as in Example 2 in the same manner as in Example 2 to obtain the initial potential characteristic, the sensitivity fluctuation in the printing durability test, the fluctuation range of the sensitivity, the appearance of interference fringe patterns, and the reflection. The maximum value of the rate was evaluated.
• Table 8 shows the results of these evaluations and the maximum values of the reflectance in each experiment together with the evaluation results of Example 2. (Table 8)
• magnesium oxide was used for the intermediate layer.However, the thickness of the intermediate layer made of other metal oxides such as aluminum oxide, titanium oxide, and lanthanum oxide was changed. A photoreceptor was fabricated and evaluated for the appearance of interference fringe patterns in a print endurance test, and the sensitivity fluctuation and sensitivity fluctuation range and the maximum reflectance were evaluated. When the thickness of the intermediate layer is adjusted to a maximum value of 20% or less, the reflection of interference fringes is suppressed, and unevenness in sensitivity and the fluctuation range of sensitivity are reduced to 1 /, and an electrophotographic photoreceptor is obtained. Was.
• An intermediate layer of controlled magnesium oxide An electrophotographic photoreceptor is manufactured by forming a surface layer made of magnesium fluoride, and evaluation of initial potential characteristics, image evaluation in a print durability test, sensitivity fluctuation and sensitivity fluctuation width, and maximum reflectance ⁇ (A direct evaluation was performed.
• the initial potential characteristics, the sensitivity fluctuation in the print durability test and the variation width of the sensitivity, and the reflection of interference fringes were obtained in the same manner as in Example 2. And the maximum value of the reflectance were evaluated.
• the ratios of the initial charging ability, the sensitivity and the residual potential, the sensitivity variation during the endurance test and the fluctuation range of the sensitivity, and the reflection fringe pattern were calculated with respect to Comparative Example 3. The evaluation was made under the following evaluation criteria.
• Table 10 summarizes the results of these evaluations and the maximum values of the reflectance in each experiment. .
• magnesium oxide was used for the intermediate layer.
• an intermediate layer made of other metal oxides such as oxide aluminum, titanium oxide, and lanthanum oxide was used to satisfy the formula (2). Even when the film was formed by adjusting the film thickness, an electrophotographic photoreceptor with good interference fringe reflection and small sensitivity unevenness and sensitivity fluctuation was obtained when the value of m was within the range of 1 to 5. .
• an intermediate layer made of magnesium oxide and a surface layer made of magnesium fluoride whose film thickness was adjusted to be an integer multiple of ⁇ ⁇ / 16 ⁇ from the film thickness satisfying equation (2) were used.
• the electrophotographic photoreceptor was formed to form an electrophotographic photoreceptor, and the initial potential characteristics were evaluated, the image was evaluated in a print durability test, the variation in sensitivity and sensitivity, and the maximum value of reflectance was evaluated. '
• the initial potential characteristics, the sensitivity fluctuation in the print durability test, the fluctuation width of the sensitivity, and the appearance of interference fringe patterns were obtained in the same manner as in Example 2.
• the appearance of the reflection and the maximum value of the reflectance were evaluated.
• the initial chargeability, the sensitivity and the residual potential, the sensitivity unevenness and the variation range of the sensitivity during the durability test, and the ratio of the interference fringe pattern reflection to the comparative example 3 were calculated. The evaluation was performed under the evaluation criteria. ⁇ : 20% or more improvement over Comparative Example 3
• Table 12 summarizes the results of these evaluations and the maximum values of the reflectance in each experiment, together with the results in Example 7.
• magnesium oxide was used for the intermediate layer, but other metal oxides such as aluminum oxide, titanium oxide, and lanthanum oxide were used for the intermediate layer, and the film thickness satisfied the expression (2). Even when the film is formed with a film thickness shifted from the value, the interference fringes can be reflected well and the sensitivity can be improved within the range of the deviation of L / 16n from the film thickness that satisfies Equation (2). An electrophotographic photoreceptor having a small variation in sensitivity was obtained.
• the sputtering apparatus shown in Fig. 6 is used to adjust the refractive index and the thickness of the intermediate layer so as to have anti-reflection properties.
• An electrophotographic photoreceptor is fabricated by forming a surface layer made of magnesium, and evaluation of initial potential characteristics, image evaluation in a print durability test, sensitivity fluctuation and sensitivity fluctuation range, and evaluation of the maximum value of reflectance are performed. Done.
• the number of the intermediate layers is one
• the value of the refractive index of the intermediate layer necessary to have the antireflection ability is calculated based on the equation (4), 2.05 is obtained.
• lanthanum oxide having a refractive index close to this value (around 1.95) was selected as the intermediate layer.
• the intermediate layer made of lanthanum oxide was formed using the sputtering apparatus shown in FIG.
• the thickness was formed such that the value of m in equation (2) was any of 1 to 7.
• ⁇ in equation (2) 405 nm, which is the main oscillation wavelength of the exposure laser light, was substituted.
• Table 13 shows the conditions for forming lanthanum oxide and the refractive index under the conditions.
• a surface layer made of magnesium fluoride was formed at 800 ⁇ .
• the forming conditions of the surface layer were the same as in Example 1.
• Table 14 shows combinations of the thickness of the intermediate layer and the surface layer in each example. (Table 14)
• the initial potential characteristics, the sensitivity fluctuation and the fluctuation range of the sensitivity in the printing durability test, the appearance of interference fringe pattern, and the maximum reflectance were obtained in the same manner as in Example 2. The values were evaluated.
• Table 15 summarizes the results of these evaluations and the maximum values of the reflectance in each experiment.
• Equation (2) shows that the residual sensitivity of the reflectance
• Example 19 1 ⁇ ⁇ ⁇ ⁇ . ⁇ ⁇ 5
• Example 20 2 ⁇ ⁇ ⁇ ⁇ ⁇ 7
• Example 21 3 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 10
• Example 22 4 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 14
• Example 23 5 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 16
• Example 24 6 ⁇ ⁇ ⁇ ⁇ ⁇ 21
• Example 25 7 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 23
• good initial potential characteristics could be obtained, and by giving the intermediate layer an antireflection function, the intermediate layer having no antireflection ability could be obtained.
• the maximum value of the reflectance can be reduced even under the same optical film thickness, that is, under the same value of m, and sensitivity unevenness and reflection of interference fringes can be reduced.
• the value of m in the equation (2) is good when the value is in the range of 1 to 5.
• Examples 2 to 26 a printing durability test was performed using a laser beam having a wavelength of 405 nm.However, even when a conventionally used wavelength of 600 to 800 nm was used, the maximum value of the reflectance was also measured. Is adjusted to be 20% or less, or the thickness of the intermediate layer is adjusted so that the value of m in the equation (2) is in the range of 1 to 5. By adjusting the refractive index of the intermediate layer so as to have the antireflection ability, it was possible to obtain an electrophotographic photoreceptor having good reflection of interference fringes, small sensitivity unevenness and small fluctuation width.

Landscapes

• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photoreceptors In Electrophotography (AREA)
• Exposure Or Original Feeding In Electrophotography (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Related Child Applications (1)

Publications (1)

Family

ID=34975745

Family Applications (1)

Country Status (3)

Families Citing this family (18)

Citations (8)

Family Cites Families (14)

• 2005
  • 2005-02-25 JP JP2005051085A patent/JP4738840B2/ja not_active Expired - Fee Related
  • 2005-03-15 WO PCT/JP2005/005072 patent/WO2005088400A1/ja not_active Ceased
  • 2005-06-22 US US11/157,990 patent/US7498110B2/en not_active Expired - Fee Related

Patent Citations (8)

Also Published As

Similar Documents

Legal Events