JP2005115063A - Image carrier in image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image carrier for more reliably performing image formation over a prolonged period of time by stably performing charging by charge injection over a prolonged period of time. <P>SOLUTION: The image carrier 1 has a conductive substrate 2, an under coated layer 3 is formed on the substrate 2, and a photosensitive layer 4 which is a laminate of a charge generation layer 5 and a charge transport layer 6 is formed on the undercoat layer 3. A charge injection layer 18 is further formed on the charge transport layer 6. In the charge transport layer 6 and the charge injection layer 18, a large number of conductive fine particles 7, 20 are independently dispersed, respectively. Thus, charging of the image carrier 1 by charge injection can be more reliably and uniformly performed in a stable manner over a prolonged period of time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technical field of an image carrier that is used in an image forming apparatus such as an electrophotography and a facsimile and forms a latent image, and in particular, has a photosensitive layer for forming a latent image by optical writing, The present invention relates to a technical field of an image carrier having a large number of conductive fine particles for charging by charge injection.

There has been proposed an image forming apparatus that charges an image carrier by injecting electric charges into the image carrier on which an electrostatic latent image is formed (see, for example, Patent Document 1). The image forming apparatus disclosed in Patent Document 1 includes a photosensitive drum that is an image carrier. The photosensitive drum includes a photoconductive layer composed of a charge generation layer that generates charges by receiving light and a charge transport layer that transports the generated charges, and a binder resin composed of phosphazene resin on the charge transport layer. And a charge injection layer formed to have a predetermined thickness by dispersing conductive filler made of SnO ₂ which is conductive fine particles. The photosensitive drum is uniformly charged by bringing the contact charging member into contact with the charge injection layer and injecting charge from the contact charging member into SnO _{2 of the} charge injection layer. Next, the photoconductive drum is exposed to a laser beam so that the charge generation layer receives light and generates a charge, and the positive charge among the generated charges is transported to the surface of the photoconductive drum by the charge transport layer. Thus, the exposed portion of the surface of the photosensitive drum is neutralized to form a latent image.

By charging the photosensitive drum by the charge injection method in this way, charging can be performed at a low voltage, so that the cost of the power source can be reduced and generation of ozone products can be prevented. Furthermore, when there is a pinhole or the like in the photosensitive drum due to charging at a low voltage, it is possible to suppress image formation defects due to leakage as much as possible.
Japanese Patent Laid-Open No. 6-3921.

  By the way, in the photosensitive drum disclosed in Patent Document 1, the surface layer of the photosensitive drum is worn by a member in contact with the photosensitive drum, for example, when image formation is performed over a long period of time. However, since the photoreceptor drum disclosed in Patent Document 1 has a charge injection layer only on the surface layer of the photoreceptor, the charge injection layer that is the surface layer of the photoreceptor drum becomes worn. When the charge injection layer is not worn, charging by charge injection cannot be performed and image formation cannot be performed. In other words, since the film thickness of the charge injection layer, which is the surface layer of the photosensitive drum, becomes the rate-determining factor of the life of the image forming apparatus, it is difficult to stably charge the photosensitive drum for a long period of time.

  Further, if filming occurs on the surface of the photosensitive drum due to, for example, long-term use of the photosensitive drum due to coating of the resin component of the toner, charging by charge injection to the charge injection layer cannot be reliably performed. Therefore, it is necessary to form an image while removing the filming by actively polishing the surface layer of the image carrier, that is, the charge injection layer. However, when the charge injection layer is polished, the thickness of the charge injection layer becomes the rate-determining factor of the life of the image forming apparatus as in the case of the wear of the charge injection layer described above, and the photosensitive drum can be stably charged over a long period of time. Becomes difficult.

  The present invention has been made in view of such circumstances, and an object of the present invention is to stably perform charging by charge injection over a long period of time so that image formation can be performed for a long period of time and more reliably. An object is to provide an image carrier in an image forming apparatus.

  In order to solve the above-mentioned problems, the invention of claim 1 is used in an image forming apparatus, wherein a photosensitive layer is formed on a conductive substrate and a charge injection layer is formed on the photosensitive layer. The image bearing member is characterized in that a large number of conductive fine particles are contained in the photosensitive layer separately dispersed.

According to a second aspect of the present invention, a large number of conductive fine particles are independently dispersed and contained in the charge injection layer, and a part of the conductive fine particles of the charge injection layer is deposited on the surface of the charge injection layer. It is characterized by being.
Further, in the invention of claim 3, the photosensitive layer is a photosensitive layer formed by laminating a charge generation layer on a conductive substrate and a charge transport layer on the charge generation layer, A large number of conductive fine particles are dispersed in the charge transport layer independently in the circumferential direction and in the film thickness direction.

  Furthermore, the invention of claim 4 is used in an image forming apparatus, and in an image carrier in which a photosensitive layer is formed on a conductive substrate, the photosensitive layer is charged on the conductive substrate. A photosensitive layer formed by laminating a generation layer and a charge transport layer on the charge generation layer, wherein the charge transport layer contains a large number of conductive fine particles dispersed independently in a circumferential direction and a film thickness direction. In addition, a part of the conductive fine particles of the charge transport layer is deposited on the surface of the charge transport layer.

Furthermore, in the invention of claim 5, the content of the conductive fine particles on the surface layer side of the charge transport layer is set high, and the content of the conductive fine particles on the substrate side of the charge transport layer is set low. It is characterized by having.
Further, in the invention of claim 6, the charge transport layer is composed of an upper layer on the surface layer side containing the conductive fine particles and a lower layer on the base material side not containing the conductive fine particles. It is characterized by.
Furthermore, the invention according to claim 7 is set such that the content of the conductive fine particles in the charge transport layer decreases continuously or in a plurality of steps from the surface layer side toward the base material side. It is characterized by.

  Further, the invention of claim 8 is used in an image forming apparatus, and is a single layer type image carrier in which a photosensitive layer having a charge generation function and a charge transport function is formed on a conductive substrate. The photosensitive layer contains a large number of conductive fine particles that are independently dispersed in the circumferential direction and the film thickness direction, and a part of the conductive fine particles of the photosensitive layer is deposited on the surface of the photosensitive layer. It is a feature.

Further, in the invention of claim 9, the content of the conductive fine particles on the surface layer side of the photosensitive layer is high, and the content of the conductive fine particles on the substrate side of the photosensitive layer is set low. It is characterized by that.
Further, the invention of claim 10 is that the photosensitive layer is composed of an upper layer on the surface layer side containing the conductive fine particles and a lower layer on the substrate side not containing the conductive fine particles. It is a feature.
Furthermore, the invention of claim 11 is such that the content of the conductive fine particles in the photosensitive layer is set to decrease continuously or in a plurality of steps from the surface layer side toward the substrate side. It is a feature.

  According to the image carrier of the invention of claim 1 to 3, 5 to 7 thus configured, charge injection is performed by laminating a photosensitive layer in which a large number of conductive fine particles are dispersed independently and a charge injection layer. Since the conductive portion to be formed has a two-stage configuration, the image carrier can be more reliably charged. Further, even if the surface layer of the image carrier is worn by increasing the number of printed sheets, the conductive fine particles can be exposed on the surface of the image carrier. As a result, the image carrier can be more stably charged over a long period of time. Therefore, latent image formation by optical writing and latent image formation by charging writing can be performed over a long period of time, and image formation by both writings can be performed for a long time and more reliably. Further, even if filming occurs due to the resin component of the toner on the surface of the image carrier due to long-term use of the image carrier, etc., by actively polishing the surface layer of the image carrier to remove this filming, New conductive fine particles can be exposed. As a result, image formation can be reliably performed for a longer period of time.

  Furthermore, according to the image carrier of the present invention, the conductive fine particles of the charge injection layer are deposited on the surface of the charge injection layer, or the conductive fine particles of the charge transport layer of the photosensitive layer are transported. Since it is deposited on the surface of the layer, the image carrier can be charged more reliably, uniformly and more stably. Further, even if the surface layer of the image carrier is worn by increasing the number of printed sheets, the conductive fine particles can be exposed on the surface of the image carrier. As a result, the image carrier can be more stably charged over a long period of time. Therefore, latent image formation by optical writing and latent image formation by charging writing can be performed over a long period of time, and image formation by both writings can be performed for a long time and more reliably.

  Further, according to the image carrier of the invention of claims 8 to 11, since the conductive fine particles of the photosensitive layer are deposited on the surface of the photosensitive layer, the image carrier is more reliably and uniformly charged. It can be performed stably. Further, even if the surface layer of the image carrier is worn by increasing the number of printed sheets, the conductive fine particles can be exposed on the surface of the image carrier. As a result, the image carrier can be more stably charged over a long period of time. Therefore, latent image formation by optical writing and latent image formation by charging writing can be performed over a long period of time, and image formation by both writings can be performed for a long time and more reliably. Further, even if filming occurs due to the resin component of the toner on the surface of the image carrier due to long-term use of the image carrier, etc., by actively polishing the surface layer of the image carrier to remove this filming, New conductive fine particles can be exposed. As a result, image formation can be reliably performed for a longer period of time.

  Further, according to the image carrier of the invention of claims 5 to 7 and 9 to 11, the content of the conductive fine particles is high on the surface layer side of the charge transport layer in the laminated type photosensitive layer, and the charge transport layer base. It is set low on the material side, and in the single-layer type photosensitive layer, it is set high on the surface side of this photosensitive layer and low on the substrate side of the photosensitive layer. Even if they are mixed in the film thickness direction of the photosensitive layer, it is possible to effectively prevent charge leakage (dielectric breakdown) that occurs when a high voltage is applied during charging, development, transfer or the like.

  Furthermore, according to the image carrier of the invention of claims 1 to 11, in the multilayer photosensitive layer, the conductive fine particles mixed in the film thickness direction of the charge transport layer also exhibit the charge transport function, and the single layer type. In this photosensitive layer, the conductive fine particles mixed in the film thickness direction of the photosensitive layer also exert a charge transport function, so that the speed of charge transport (for example, photoreaction speed (charge generation during latent image formation by optical writing) The transport speed of charges generated by light reception by the material is improved. Therefore, it is possible to effectively cope with speeding up and downsizing of the image forming apparatus.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view schematically and partially showing a first example of an embodiment of an image carrier in an image forming apparatus of the present invention.

  As shown in FIG. 1, the image carrier 1 of the first example includes a base material 2, an undercoating layer (hereinafter also referred to as UCL) 3 formed on the base material 2, The photosensitive layer 4 is formed on the UCL 3 and the charge injection layer 18 is formed on the photosensitive layer 4. The photosensitive layer 4 includes a charge generation layer (hereinafter also referred to as CGL) 5 formed on the UCL 3 and a charge transport layer (hereinafter also referred to as CTL) 6 formed on the CGL 5. Are laminated. The CTL 6 and the charge injection layer 18 contain a large number of conductive fine particles 7 and 20 that are separately dispersed so as to be mixed in the circumferential direction and the film thickness direction (radial direction).

  By providing the CGL 5 and the CTL 6 in this manner, the image carrier 1 is configured as a function-separated type and a laminated type photosensitive member in which the charge generation function and the charge transport function are separated. In addition, the DTL 6 in which a large number of conductive fine particles 7 are independently dispersed and the charge injection layer 18 in which a large number of conductive fine particles 20 are independently dispersed are stacked, so that a conductive portion into which charges are injected has a two-stage configuration. ing.

The base material 2 is formed in a cylindrical shape from a conductive material such as aluminum. In this case, the outer diameter is about 30 mm and the thickness is 1 to 2 mm.
The UCL 3 is a layer of an electrically insulating thin film provided for the purpose of preventing the injection of electric charges from the surface of the photosensitive layer 4 or the substrate 2, and is formed of, for example, a resin layer such as an amylan resin or an alumite layer. . The film thickness of this UCL3 is 0.5-5 micrometers, Preferably it is 0.5-1.5 micrometers.

  CGL5 is a layer that shares the function of generating charge when receiving light with a function-separated / stacked type photoreceptor, and is formed by dispersing a charge generating material (hereinafter also referred to as CG material) in a binder resin, as described above. There is a type in which an amorphous Si layer is formed on a base material 2 by vacuum deposition. The film thickness of CGL5 is 0.5 to 2 μm, preferably 0.5 to 1.5 μm.

In the type in which the charge generating material is dispersed in the binder resin, for example, a resin such as polyvinyl butyral resin can be used as the binder resin, and a bisazo type or phthalocyanine type pigment can be used as the CG material. . The CGL 5 is formed by applying a charge generation material on the UCL 3 to a predetermined film thickness within the aforementioned film thickness range. By using a bisazo or phthalocyanine pigment, the image carrier 1 is configured as an organic photoreceptor (OPC).
In the type in which an amorphous Si layer is vacuum-deposited on the substrate 2, when the amorphous Si is vacuum-deposited, the conductive fine particles 7 are also vacuum-deposited to form the CGL 5. The image carrier 1 is configured as an inorganic photoreceptor.

  CTL6 is a layer that shares the function of transporting charges generated by CGL5 in a functionally separated / stacked type photoconductor, and in the binder resin that exhibits properties as a dielectric, similar to conventional binder resins for photoconductors. And a compound having a charge transporting property (hereinafter also referred to as a CT material). As the binder resin, for example, a resin having dielectric properties such as polycarbonate, polyethylene, polyvinyl chloride, polyolefin, polyethylene terephthalate, or the like can be used. Further, as the CT material, for example, a hydrazone-based charge transport material can be used. The CTL 6 is formed by applying a predetermined film thickness (10 to 30 μm) on the CGL 5.

Further, as the conductive fine particles 7 dispersed independently in the CTL 6, metal fine particles such as W, Mo, Ta, Au, Ag and Fe, or tin oxide (SnO ₂ ) is doped with antimony or indium. Thus, fine particles such as conductive fine particles, or other metal oxides such as titanium oxide (TiO ₂ ) or conductive carbon can be used. In this case, the image carrier 1 according to the present invention performs both latent image formation by latent image formation by optical writing and latent image formation by charging writing without using light. Fine particles obtained by conducting SnO ₂ having optical transparency as described above, or fine particles having a finer particle size of sub-μm (1 μm) or less that do not impair optical transparency in the case of optical writing. It is preferable to use it.

  In the image carrier 1 of the first example, the content of the conductive fine particles 7 is relatively high in the upper layer (that is, the surface layer side) A of the CTL 6 and the lower layer of the CTL 6 (that is, on the substrate 2 side). Layer) B is set to be relatively low. The content rate of the conductive fine particles 7 is defined by the area covered by the conductive fine particles 7 per unit area on a surface of a certain radius in the CTL 6.

  The evaluation of the content of the conductive fine particles 7 on the surface having a certain radius can be performed as follows as an example. That is, the surface of the CTL 6 whose surface layer is cut is exposed to the surface. Then, the exposed surface is observed with an optical microscope, and the area of the conductive fine particles 7 covering the exposed surface per unit area of the exposed surface is measured to evaluate the content of the conductive fine particles 7 on the surface. I do. In addition, within the set area of the exposed surface, the area where the conductive fine particles 7 cover the exposed surface within the set area is measured, and the conductive fine particle 7 is divided by the set area of the exposed surface by dividing the conductive area. The content of the conductive fine particles 7 can also be evaluated.

  When the CTL 6 containing the conductive fine particles 7 is applied on the CGL 5, the application is performed in a state where the conductive fine particles 7 are contained in the CT material and the binder resin and these are dissolved in a solvent. In that case, THF or acetone can be used as the solvent, but the solvent is not limited to this, and any solvent that dissolves the binder resin may be used.

  The charge injection layer 18 is configured by a large number of conductive fine particles 20 being dispersed substantially uniformly in a binder resin 19. The thickness of the charge injection layer 18 is 1 to 15 μm, preferably 2 to 5 μm. This is because if the thickness of the charge injection layer 18 is too thin, the charge injection layer 18 will not be scraped, resulting in poor durability. If the thickness of the charge injection layer 18 is too thick, it absorbs optical energy during optical writing (that is, This is because the latent image data subjected to optical writing may cause a leakage in the surface direction in the charge injection layer 18 and blur the latent image.

As the binder resin 19, for example, a resin such as a phosphazene resin, a polycarbonate resin, a polyacetylene resin, a polyimide resin, a polyvinyl acetate resin, or the like can be used. Any resin can be used as long as the resin exhibits dielectric properties. For the conductive fine particles 20, the same material as that of the conductive fine particles 7 dispersed independently in the charge transport layer 6 can be used. In that case, it is preferable to use SnO ₂ particles having a high light transmittance in order to reliably and efficiently reach the light to the CGL 5 at the time of optical writing by exposure. In addition, when using fine particles other than SnO ₂ particles having good light transmittance, fine particles having a finer particle diameter of sub-μm (1 μm) or less, which do not hinder the light transmission in the case of optical writing, should be used. preferable.

Next, an example of a manufacturing method of the image carrier 1 of the first example configured as described above will be described.
The manufacturing method of the image carrier 1 configured as OPC is basically the same as that of a conventionally known ordinary photosensitive drum, and the image carrier 1 is manufactured by a dip coating method (a water immersion method). Can do. More specifically, first, for example, a certain degree of ionic conductivity is applied to an insulating amylan resin, for example, on a cylindrical base material 2 made of an aluminum material and having an outer diameter of about 30 mm and a thickness of 1.5 μm. By applying a UCL liquid mixed with the methoxymethylated nylon shown, the electrically insulating thin film UCL3 is formed to a thickness of about 1 μm.

  Next, on the formed UCL3, a dispersion of polyvinyl butyral resin, which is a binder resin, and bisazo pigment, which is a charge generation material, in a weight ratio of 1: 2 is applied to reduce CGL5 to about The film is formed to a thickness of 1 μm. Next, on the formed CGL5, a CTL resin in which a polycarbonate resin as a binder resin and a hydrazone as a CT material are dispersed at a weight ratio of 1: 1, and Mo fine particles (Co., Ltd.) as conductive fine particles 7 High Purity Science Laboratory) is dissolved in a THF solvent, and a CTL coating liquid in which the conductive fine particles 7 are independently dispersed is applied.

  In that case, the conductivity on the surface layer side of CTL6 can be obtained simply by coating the CTL coating liquid by the same coating method as that of a conventional ordinary photosensitive drum as disclosed in Patent Document 1. The content of the fine particles 7 cannot be made higher than the content of the conductive fine particles 7 on the substrate 2 side. Therefore, in the image carrier 1 of the first example, the coating is divided into two times, and the following first and second coatings are respectively used as the CTL coating liquid in the first and second coatings. By using the working solution, the concentration of the conductive fine particles 7 in the photosensitive layer 4 is changed.

  That is, in this example, the first coating liquid used for the first coating is produced as follows. Mo fine particles having an average number particle size of 3 μm (manufactured by Kokusai Kagaku Kenkyusho Co., Ltd.) are in a weight ratio A% (for example, 15%), and the above-mentioned CTL resin is in a weight ratio (100-A)% (for example, 85% ) And a solution is prepared using THF as a solvent so that the concentration of solids (conductive fine particles 7 and CTL resin) is 20% by weight. Then, the first coating liquid is completed by putting a solution containing Mo fine particles having an average particle diameter of 3 μm, a resin for CTL, and THF together with glass beads in a 500 ml container and dispersing with a paint shaker. To do.

  Moreover, the 2nd coating liquid used for the 2nd coating is produced as follows. Mo fine particles having an average number particle size of 3 μm (manufactured by High Purity Science Laboratory Co., Ltd.) having a weight ratio B% (B> A; for example, 25%) larger than the aforementioned weight ratio A%, and the aforementioned CTL resin weight. A solution is prepared using THF as a solvent so that the ratio (100-B)% (for example, 75%) and the solid content concentration is 20% by weight. Then, a solution in which Mo fine particles having an average number particle diameter of 3 μm, a CTL resin, and THF are mixed together is placed in a 500 ml container together with glass beads in the same manner as the first coating liquid, and dispersed by a paint shaker. To complete the second coating liquid.

Then, the first coating film is formed on the CGL 5 by applying the first coating liquid on the CGL 5 and drying it in the first coating. Next, a second coating film is formed on the first coating film by applying the second coating liquid onto the first coating film and drying it in the second coating. At this time, since the solid content concentrations (mixing ratios) of the first coating liquid and the second coating liquid are different from each other, the viscosity of each coating liquid is slightly different, but the first coating and the second coating are performed. In any of these coating methods, the coating speed can be set substantially the same.
In this way, the conductive fine particles 7 on the surface layer side are coated by changing the concentration of the conductive fine particles 7 in the coating liquid to be low in the first coating and high in the second coating. CTL6 whose content rate is higher than the content rate of the conductive fine particles 7 on the substrate 2 side can be formed.

Next, on the formed CTL 6, fine particles of tin oxide (SnO ₂ ) obtained by conducting antimony or indium as the conductive fine particles 20 on the phosphazene resin which is a binder resin and conducting the conductive treatment are added by 70 wt% ( (Weight of conductive fine particles / weight of binder resin) × 100%) By applying an independently dispersed material, the charge injection layer 18 is formed to a thickness of about 5 μm. Thus, the image carrier 1 of the first example is manufactured.

  The image carrier 1 of the first example can be charged by charge injection because a large number of conductive fine particles 7 are independently dispersed in the charge transport layer 6 of the photosensitive layer 4. Moreover, since the charge injection layer 18 in which a large number of conductive fine particles 20 are independently dispersed is formed on the charge transport layer 6 in which the conductive fine particles 7 are dispersed independently, charge injection is more effectively performed. Therefore, charging by charge injection is more reliable.

  Therefore, the image carrier 1 can form either a latent image by charging writing or a latent image by optical writing. That is, the image carrier 1 of the first example can be applied to an image forming apparatus 9 that forms a latent image by charging writing as shown in FIG. The image forming apparatus 9 includes a writing head 10 that writes an electrostatic latent image on the image carrier 1, a flexible base 11 that supports the writing head 10, a developing roller 12a that is a developer carrier, and The image forming apparatus includes at least a developing device 12 having a developer layer thickness regulating member 12b that regulates a layer thickness of the developer (toner) on the developing roller 12a and a transfer device 13 having a transfer roller 13a.

  Then, the write head 10 is brought into contact with the charge injection layer 18, and charges are injected into the conductive fine particles 20 on the surface of the charge injection layer 18 by the writing voltage of the write head 10, whereby the latent image becomes an image carrier. 1 is written. The latent image written on the image carrier 1 is developed by the developer (toner) of the developing device 12, and the developer (toner) image is transferred to a transfer material such as paper (not shown) by the transfer device 13. The developer (toner) image transferred to the transfer material is fixed by a fixing device (not shown), and an image is formed on the transfer material.

  The image carrier 1 of the first example can also be applied to an image forming apparatus 9 that forms a latent image by optical writing as shown in FIG. The image forming apparatus 9 includes a charging device 14 for uniformly charging the image carrier 1, an exposure device 15 for writing an electrostatic latent image on the image carrier 1 by exposure, and development similar to the developing device 12 shown in FIG. The apparatus 12 includes at least a transfer apparatus 13 similar to the transfer apparatus 13 illustrated in FIG.

  Then, for example, a charging roller of the charging device 14 is brought into contact with the charge injection layer 18, and charges are injected into the conductive fine particles 20 of the charge injection layer 18 of the image carrier 1 by the charging voltage of the charging roller, thereby carrying the image carrier. The body 1 is uniformly charged. When the charged image carrier 1 is exposed by the exposure device 15, the CGL 5 receives this light to generate charges, and the charges are transported to the surface by the CTL 6 and the conductive fine particles 20 of the charge injection layer 18. A latent image is written on the image carrier 1. Thereafter, development, transfer, and fixing are performed in the same manner as in the case of the image forming apparatus 9 shown in FIG. 2, and an image is formed on the transfer material.

  In the above-described charging writing and optical writing, even if the charge injection layer 18 is not worn due to long-term use of the image carrier 1, the conductive fine particles 7 on the surface of the CTL 6 appear. The latent image is written on the image carrier 1 by injecting electric charges in contact with the conductive fine particles 7. The latent image written on the image carrier 1 is developed, transferred, and fixed in the same manner as described above to form an image on a transfer material such as paper.

  In the image carrier 1 of the first example shown in FIG. 1, the UCL 3 is provided on the substrate 2, but this UCL 3 can be omitted. Therefore, the formation of the photosensitive layer 4 on the substrate 2 in the present invention means that the photosensitive layer 4 is formed directly on the substrate 2 and the photosensitive layer 4 is formed on the substrate 2 via the UCL 3. In any case.

  As a modification of the first example, although not shown, a charge injection preventing layer (hereinafter also referred to as CPL) similar to the image carrier disclosed in Patent Document 1 may be provided between the substrate 2 and the UCL 3. it can. With this CPL8, it is possible to more reliably prevent charge injection between the substrate 2 and each coating layer (UCL3, CGL5, CTL6) thereon.

As described above, according to the image carrier 1 of the first example and the modification thereof, the charge injection layer 18 in which the large number of conductive fine particles 20 are independently dispersed on the CTL 6 in which the large number of conductive fine particles 7 are independently dispersed. Therefore, it is possible to reliably charge the image carrier 1 by charge injection.
Further, even if the charge injection layer 18 is not worn due to an increase in the number of printed sheets, the conductive fine particles 7 on the surface of the CTL 6 are exposed, so that the image carrier 1 can be charged more stably over a long period of time. . Therefore, latent image formation by optical writing and latent image formation by charging writing can be performed over a long period of time, and image formation by both writings can be performed for a long time and more reliably. In this case, even if filming occurs on the surface of the charge injection layer 18 due to the resin component of the toner due to long-term use of the image carrier 1, the surface layer of the charge injection layer 18 is actively polished to remove this filming. As a result, new conductive fine particles 20 can be exposed.

  Further, after the charge injection layer 18 is removed, even if similar filming occurs on the surface of the CTL 6, the surface layer of the CTL 6 is actively polished to remove this filming. Can be exposed. Therefore, even if filming occurs on the surface of the image carrier 1, the image carrier 1 can be stably charged for a long period of time, and image formation can be reliably performed for a longer period of time. .

  Further, when a large number of conductive fine particles 7 are mixed in the film thickness direction of the CTL 6, when a high voltage is applied in charging, development, transfer, etc., charge is transferred in the depth direction (film thickness direction) of the image carrier 1. Leakage (insulation breakdown) occurs. However, according to the image carrier 1 of the first example and its modified example, the content of the conductive fine particles 7 is set to be high on the surface layer side of the CTL 6 and low on the base material 2 side of the CTL 6. Even if the conductive fine particles 7 are mixed in the film thickness direction of the CTL 6, it is possible to effectively prevent charge leakage (dielectric breakdown) in the depth direction of the image carrier 1.

  Furthermore, since the conductive fine particles 7 mixed in the film thickness direction of the CTL 6 and the conductive fine particles 20 of the charge injection layer 18 also exhibit a charge transport function, the speed in charge transport (for example, photoreaction speed (by optical writing) When the latent image is formed, the transport speed of charges generated by light reception by the CGL 5) is improved. Therefore, it is possible to effectively cope with speeding up and downsizing of the image forming apparatus.

FIG. 4 is a cross-sectional view similar to FIG. 1, schematically and partially showing a second example of the embodiment of the image carrier of the present invention. In the description of each example of the following embodiment, the same components as those described before the example are denoted by the same reference numerals, and detailed description thereof is omitted.
In the image carrier 1 of the first example shown in FIG. 1 described above, the conductive fine particles 7 are contained on the base 2 side of the CTL 6, but as shown in FIG. 4, the image carrier 1 of the second example is shown. Then, the conductive fine particles 7 are not contained in the lower layer (that is, the layer on the base material 2 side) B of the CTL 6. The upper layer (namely, the surface layer side) A of the CTL 6 contains a large number of conductive fine particles 7 that are independently dispersed as described above.
Thus, even when the conductive fine particles 7 are not contained in the lower layer (that is, the layer on the base material 2 side) B of the CTL 6, the content of the conductive fine particles 7 is high on the surface layer side of the CTL 6, and the base material 2 side of the CTL 6 And low in the image carrier 1 of the present invention.

In the method for manufacturing the image carrier 1 of the second example, the coating liquid is applied in two steps in the same manner as in the method for manufacturing the image carrier 1 of the first example. In the first coating of the coating liquid, a CTL coating liquid that does not contain the conductive fine particles 7 is used. In the second coating of the CTL coating liquid, the conductive fine particles 7 are formed in exactly the same way as the CTL coating liquid used in the second coating in the manufacturing method of the image carrier 1 of the first example. The contained CTL coating solution is used. Other steps of the manufacturing method of the image carrier 1 of the second example are the same as the manufacturing method of the image carrier 1 of the first example.
The other configurations and other functions and effects of the image carrier 1 of the second example are the same as those of the image carrier 1 of the first example.

FIG. 5 is a cross-sectional view similar to FIG. 1 schematically and partially showing a third example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the first example shown in FIG. 1 described above, the content of the conductive fine particles 7 in the upper layer A of the CTL 6 is set high, and the content of the conductive fine particles 7 in the lower layer B of the CTL 6 is set low. However, as shown in FIG. 5, in the image carrier 1 of the third example, the content of the conductive fine particles 7 gradually (continuously or in a plurality of steps) from the surface layer side of the CTL 6 toward the substrate 2 side. The content of the conductive fine particles 7 having a gradation structure is set to be lower (gradually decreased).

A method for manufacturing the image carrier 1 of the third example will be described.
In the manufacturing method of the image carrier 1 of the first and second examples described above, the CTL coating liquid is applied in two steps. In the manufacturing method of the image carrier 1 of the third example, the CTL coating liquid is used. Apply the coating liquid in three or more times. In that case, the conductive liquid 7 is not included in the CTL coating liquid used in the first coating, or even if the conductive fine particles 7 are included, the content is set to be the lowest. The content of the conductive fine particles 7 in the CTL coating liquid used in the second coating is set to be slightly higher than that in the first CTL coating liquid, and the CTL coating liquid used in the third coating is further increased. The content of the conductive fine particles 7 is set to be slightly higher than that of the second CTL coating liquid, and the content of the conductive fine particles 7 of the CTL coating liquid is gradually increased as the number of coatings is increased. Set to

In this manner, the CTL coating liquid having a gradually increasing content of the conductive fine particles 7 is sequentially applied in three or more times, so that the content of the conductive fine particles 7 is the above-described gradation structure. An image carrier 1 is formed. The other steps of the manufacturing method of the image carrier 1 of the third example are the same as the manufacturing method of the image carrier 1 of the first example.
The other configurations and other functions and effects of the image carrier 1 of the third example are the same as those of the image carrier 1 of the first example.

FIG. 6 is a cross-sectional view similar to FIG. 1, schematically and partially showing a fourth example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the first to third examples described above, the conductive fine particles 20 are simply dispersed independently in the charge injection layer 18. However, in the image carrier 1 of the fourth example as shown in FIG. In addition, a large number of conductive fine particles 20 are independently dispersed in the charge injection layer 18, and a part of the conductive fine particles 20 is deposited on the surface of the charge injection layer 18.

As a method for precipitating the conductive fine particles 20 in this way, a THF or acetone solvent is applied to the charge injection layer 18 in which a large number of the conductive fine particles 20 are independently dispersed in the image carrier 1 manufactured by the above-described method. The conductive fine particles 20 are deposited by dissolving the binder resin 19 of the charge injection layer 18 by application by a dip method or a spray method. The solvent is not limited to THF or acetone, and any solvent that dissolves the binder resin 19 may be used.
Further, in the image carrier 1, the conductive fine particles 20 are deposited by polishing the surface layer of the charge injection layer 18 in which a large number of the conductive fine particles 20 are independently dispersed by, for example, a mechanical means such as a wrinkle or sandblasting process. It can also be made.

According to the image carrier 1 of the fourth example, since the conductive fine particles 20 are deposited on the surface of the charge injection layer 18 of the image carrier 1, when charging by charge injection is performed, Uniform charging can be realized with certainty.
Other configurations, other operational effects, and other manufacturing methods of the image carrier 1 of the fourth example are the same as those of the image carrier 1 of the first example.

FIG. 7 is a cross-sectional view similar to FIG. 1, schematically and partially showing a fifth example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the fourth example shown in FIG. 6 described above, the conductive fine particles 7 are contained on the substrate 2 side of the CTL 6, but in the image carrier 1 of the fifth example as shown in FIG. As in the second example, the conductive fine particles 7 are not contained in the lower layer (that is, the layer on the base material 2 side) B of the CTL 6. The upper layer (namely, the surface layer side) A of the CTL 6 contains a large number of conductive fine particles 7 that are independently dispersed as described above.

In the manufacturing method of the image carrier 1 of the fifth example, the manufacturing method of the CTL 6 is the same as the manufacturing method of the CTL 6 of the second example described above, and the manufacturing methods of the other parts are the same as those of the fourth example described above. This is the same as the manufacturing method of the image carrier 1.
The other configurations and other functions and effects of the image carrier 1 of the fifth example are the same as those of the image carrier 1 of the fourth example.

FIG. 8 is a cross-sectional view similar to FIG. 1, schematically and partially showing a sixth example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the fourth example shown in FIG. 6 described above, the content of the conductive fine particles 7 in the upper layer A of the CTL 6 is set high, and the content of the conductive fine particles 7 in the lower layer B of the CTL 6 is set low. However, as shown in FIG. 8, in the image carrier 1 of the sixth example, the content of the conductive fine particles 7 is gradually (continuously or in a plurality of steps) from the surface layer side of the CTL 6 toward the substrate 2 side. The content of the conductive fine particles 7 having a gradation structure is set to be lower (gradually decreased).

A method for manufacturing the image carrier 1 of the sixth example will be described.
In the method for manufacturing the image carrier 1 of the fourth and fifth examples described above, the CTL coating liquid is applied in two steps. In the method for manufacturing the image carrier 1 of the sixth example, the CTL coating liquid is used. Apply the coating liquid in three or more times. In that case, the conductive liquid 7 is not included in the CTL coating liquid used in the first coating, or even if the conductive fine particles 7 are included, the content is set to be the lowest. The content of the conductive fine particles 7 in the CTL coating liquid used in the second coating is set to be slightly higher than that in the first CTL coating liquid, and the CTL coating liquid used in the third coating is further increased. The content of the conductive fine particles 7 is set to be slightly higher than that of the second CTL coating liquid, and the content of the conductive fine particles 7 of the CTL coating liquid is gradually increased as the number of coatings is increased. Set to

In this manner, the CTL coating liquid having a gradually increasing content of the conductive fine particles 7 is sequentially applied in three or more times, so that the content of the conductive fine particles 7 is the above-described gradation structure. An image carrier 1 is formed. The other steps of the manufacturing method of the image carrier 1 of the sixth example are the same as the manufacturing method of the image carrier 1 of the fourth example.
The other configurations and other functions and effects of the image carrier 1 of the sixth example are the same as those of the image carrier 1 of the fourth example.

FIG. 9 is a cross-sectional view similar to FIG. 1 schematically and partially showing a seventh example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the fourth to sixth examples described above, some of the conductive fine particles 20 are deposited on the surface of the charge injection layer 18 provided on the CTL 6, but as shown in FIG. In the image carrier 1 of the seventh example, the charge injection layer 18 is not provided on the CTL 6, and a large number of conductive fine particles 7 are contained in the CTL 6 while being dispersed independently, and part of the conductive material is included. Fine particles 7 are deposited on the surface of CTL 6.

As a method for depositing the conductive fine particles 7 in this manner, in the image carrier 1 manufactured by the above-described method, as in the above-described fourth example, a number of conductive fine particles 7 are independently dispersed in CTL 6 in THF. Or the solvent of acetone is apply | coated by the dip method or the spray method, and the conductive fine particle 7 is deposited by melt | dissolving the binder resin of CTL6. The solvent is not limited to THF or acetone, and any solvent that dissolves the binder resin of CTL6 may be used.
Further, in the image carrier 1, the conductive fine particles 7 may be deposited by polishing the surface layer of the CTL 6 in which a large number of the conductive fine particles 7 are dispersed independently by a mechanical means such as a wrinkle or sandblasting process. it can.

According to the image carrier 1 of the seventh example, since the conductive fine particles 7 are deposited on the surface of the CTL 6 of the image carrier 1, when charging is performed by charge injection, the image carrier 1 is uniformly charged. It can be realized reliably.
Other configurations, other operational effects, and other manufacturing methods of the image carrier 1 of the seventh example are the same as those of the image carrier 1 of the first example.

FIG. 10 is a cross-sectional view similar to FIG. 1, schematically and partially showing an eighth example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the seventh example shown in FIG. 9 described above, the conductive fine particles 7 are contained on the substrate 2 side of the CTL 6, but in the image carrier 1 of the eighth example as shown in FIG. As in the second example, the conductive fine particles 7 are not contained in the lower layer (that is, the layer on the base material 2 side) B of the CTL 6. Further, the upper layer (namely, the surface layer) A of the CTL 6 contains a large number of conductive fine particles 7 dispersed and dispersed in the same manner as described above, and some of the conductive fine particles 7 are present on the surface of the CTL 6. It is deposited.

In the manufacturing method of the image carrier 1 of the eighth example, the manufacturing method of the CTL 6 is the same as the manufacturing method of the CTL 6 of the second example described above, and the manufacturing methods of the other parts are the same as those of the seventh example described above. This is the same as the manufacturing method of the image carrier 1.
The other configurations and other functions and effects of the image carrier 1 of the eighth example are the same as those of the image carrier 1 of the seventh example.

FIG. 11 is a cross-sectional view similar to FIG. 1, schematically and partially showing a ninth example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the seventh example shown in FIG. 9 described above, the content of the conductive fine particles 7 in the upper layer A of the CTL 6 is set high, and the content of the conductive fine particles 7 in the lower layer B of the CTL 6 is set low. However, as shown in FIG. 11, in the image carrier 1 of the ninth example, the content of the conductive fine particles 7 gradually (continuously or in a plurality of steps) from the surface layer side of the CTL 6 toward the base material 2 side. The content of the conductive fine particles 7 having a gradation structure is set to be lower (gradually decreased).

A method for manufacturing the image carrier 1 of the ninth example will be described.
In the manufacturing method of the image carrier 1 of the seventh and eighth examples described above, the CTL coating liquid is applied in two steps. In the manufacturing method of the image carrier 1 of the ninth example, the CTL coating liquid is used. Apply the coating liquid in three or more times. In that case, the conductive liquid 7 is not included in the CTL coating liquid used in the first coating, or even if the conductive fine particles 7 are included, the content is set to be the lowest. The content of the conductive fine particles 7 in the CTL coating liquid used in the second coating is set to be slightly higher than that in the first CTL coating liquid, and the CTL coating liquid used in the third coating is further increased. The content of the conductive fine particles 7 is set to be slightly higher than that of the second CTL coating liquid, and the content of the conductive fine particles 7 of the CTL coating liquid is gradually increased as the number of coatings is increased. Set to

In this manner, the CTL coating liquid having a gradually increasing content of the conductive fine particles 7 is sequentially applied in three or more times, so that the content of the conductive fine particles 7 is the above-described gradation structure. An image carrier 1 is formed. Then, the conductive fine particles 7 are deposited by applying a solvent of THF or acetone to the CTL 6 in which a large number of the conductive fine particles 7 are dispersed independently by dipping or spraying to dissolve the binder resin of the CTL 6. The solvent is not limited to THF or acetone, and any solvent that dissolves the binder resin of CTL6 may be used. Other steps of the manufacturing method of the image carrier 1 of the ninth example are the same as the manufacturing method of the image carrier 1 of the seventh example.
The other configurations and other functions and effects of the image carrier 1 of the ninth example are the same as those of the image carrier 1 of the seventh example.

FIG. 12 is a cross-sectional view similar to FIG. 1, schematically and partially showing a tenth example of an embodiment of an image carrier of the present invention.
The image carrier 1 of the first to ninth examples described above is configured as a function-separated type / layered type image carrier 1 in which the photosensitive layer 4 is separated and laminated on the CGL 5 and the CTL 6, as shown in FIG. As described above, the image carrier 1 of the tenth example is configured as a single-layer image carrier 1 in which the photosensitive layer 4 has both of these functions in one layer without separating the charge generation function and the charge transport function. ing.

  That is, the photosensitive layer 4 in the image carrier 1 of the tenth example is configured by a large number of photoconductive fine particles 17 being dispersed almost uniformly in a binder resin 16. As the binder resin 16, for example, a resin such as a polycarbonate resin, a polyacetylene resin, a polyimide resin, or a polyvinyl acetate resin can be used. However, the binder resin 16 is not limited thereto, and has insulating properties and dielectric properties. Any resin can be used as long as the resin exhibits the above. The photoconductive fine particles 17 have both a charge generation function and a charge transport function, and zinc oxide particles, phthalocyanine pigments, and the like can be used.

  Further, the resin 16 contains a large number of conductive fine particles 7 which are dispersed independently in the circumferential direction and the film thickness direction (radial direction) of the photosensitive layer 4. In that case, like the image carrier 1 of the first example, the content of the conductive fine particles 7 is relatively high in the upper layer (that is, the surface layer side) C of the photosensitive layer 4, and the lower layer (that is, the surface of the photosensitive layer 4) The layer 2 on the substrate 2 side) D is set to be relatively low. The content of the conductive fine particles 7 at this time is defined by the area covered by the conductive fine particles 7 per unit area on a surface of a certain radius in the photosensitive layer 4.

A method for manufacturing the image carrier 1 of the tenth example will be described.
The process of forming UCL3 on the aluminum base 2 is the same as in the first example. Next, a photosensitive layer material in which a polycarbonate resin as a binder resin and a phthalocyanine pigment as a photoconductive fine particle 17 are dispersed at a weight ratio of 1: 1 on the formed UCL3, and the conductive fine particle 7 are obtained. Mo fine particles (manufactured by High Purity Science Laboratory Co., Ltd.) are dissolved in a THF solvent, and a coating liquid in which the conductive fine particles 7 are independently dispersed is applied.
In that case, the coating is divided into two in the same manner as in the first example, and the following first and second coatings are used as coating liquids in the first and second coatings, respectively. By using the solution, the concentration of the conductive fine particles 7 in the photosensitive layer 4 is changed.

  That is, in the tenth example, the first coating liquid used for the first coating is produced as follows. Mo fine particles having an average number particle size of 3 μm (manufactured by Kokusai Kagaku Kenkyusho Co., Ltd.) are in a weight ratio of C% (for example, 15%), and the photosensitive layer material is in a weight ratio of (100-C)% (for example, 85). %), And a solution is prepared using THF as a solvent so that the concentration of solids (conductive fine particles 7 and photosensitive layer material) is 20% by weight. Then, a solution in which Mo fine particles having an average number particle diameter of 3 μm, a photosensitive layer material, and THF are mixed together is put together with glass beads in a 500 ml container, and dispersed by a paint shaker, whereby the first coating liquid is obtained. Complete.

  Moreover, the 2nd coating liquid used for the 2nd coating is produced as follows. Mo fine particles having an average number particle size of 3 μm (manufactured by High Purity Science Laboratory Co., Ltd.) having a weight ratio D% (D> C; for example, 25%) larger than the above-mentioned weight ratio C%, A solution is prepared using THF as a solvent so that the weight ratio (100-D)% (for example, 75%) and the solid content concentration is 20% by weight. Then, a solution in which Mo fine particles having an average number particle size of 3 μm, a photosensitive layer material, and THF are mixed together is put in a 500 ml container together with glass beads in the same manner as in the case of the first coating solution. The second coating liquid is completed by dispersing.

The first coating and the second coating are the same as in the case of the image carrier 1 of the first example described above, and the conductive fine particles on the surface layer side of the photosensitive layer 4 are obtained by these two coatings. The image carrier 1 of the tenth example in which the content rate of 7 is higher than the content rate of the conductive fine particles 7 on the substrate 2 side can be produced. Other configurations, other operational effects, and other manufacturing methods of the image carrier 1 of the tenth example are the same as those of the image carrier 1 of the first example.
The image carrier 1 of the tenth example can also form either a latent image by charging writing or a latent image by optical writing.

FIG. 13 is a cross-sectional view similar to FIG. 1 schematically and partially showing an eleventh example of the embodiment of the image carrier of the present invention.
In the image carrier 1 of the tenth example shown in FIG. 12 described above, the conductive fine particles 20 are simply dispersed independently in the charge injection layer 18, but the image carrier 1 of the eleventh example is shown in FIG. Then, a large number of conductive fine particles 20 are independently dispersed in the charge injection layer 18, and a part of the conductive fine particles 20 is transferred to the charge injection layer 18 as in the fourth to sixth examples shown in FIGS. It is deposited on the surface.
The method for depositing the conductive fine particles 20 in this way is the same as in the fourth to sixth examples.

According to the image carrier 1 of the eleventh example, since the conductive fine particles 20 are deposited on the surface of the charge injection layer 18 of the image carrier 1, when charging by charge injection is performed, the image carrier 1 Uniform charging can be realized with certainty.
Other configurations, other operational effects, and other manufacturing methods of the image carrier 1 of the eleventh example are the same as those of the image carrier 1 of the tenth example.

  In the first to eleventh examples described above, the content of the conductive fine particles 7 independently dispersed in the CTL 6 and the photosensitive layer 4 is changed, but there is a problem of charge leakage in the depth (film thickness) direction. In the case where there is no possibility of the occurrence of such, there is no need to change the content of the conductive fine particles 7. However, in order to surely solve this leakage problem, it is preferable to change the content of the conductive fine particles 7 as in the above-described examples.

  In the first to eleventh examples, the coating liquid is dispersed by a paint shaker. The ultrasonic vibrator is composed of Mo fine particles having an average number particle size of 3 μm, a CTL resin, and THF. The coating liquid may be dispersed by using ultrasonic vibration energy in a mixed solution, and the coating liquid may be dispersed by other dispersion methods such as simple vibration and stirring. You can also. Furthermore, by using Micropearl AU (manufactured by Sekisui Chemical Co., Ltd.) as the conductive fine particles 7 and 20, a coating liquid can be easily produced. Since this micropearl AU is manufactured in which AU is metal-plated on the outer periphery of the resin fine particles, the specific gravity is smaller than that of the metal fine particles, and the dispersibility of the coating solution is improved when the photosensitive layer 4 is applied. Therefore, the effect of improving the productivity in the coating process can be expected.

The image carriers 1 of the second to eleventh examples are also applied to the latent image forming image forming apparatus 9 by charge writing shown in FIG. 2 and the latent image forming image forming apparatus 9 shown in FIG. can do.
Further, in the image carriers of the tenth and eleventh examples, the photosensitive layer 4 is formed by simultaneously dispersing the CG material and the CT material in the binder resin 16 instead of the photoconductive fine particles 17. You can also.

  Further, as another example of the image carrier in which the photosensitive layer 4 of the tenth and eleventh examples is a single layer, the arrangement configuration of the conductive fine particles 7 dispersed independently in the photosensitive layer 4 is shown in FIGS. 7 and FIG. 8 may be the same as the arrangement of the conductive fine particles 7 that are independently dispersed in the CTLs 6 of the second example, the third example, the fifth example, and the sixth example. Further, as another example of the image carrier in which the photosensitive layer 4 of the tenth and eleventh examples is a single layer, conductive materials that are independently dispersed in the CTLs 6 of the seventh to ninth examples shown in FIGS. 9 to 11, respectively. In the same manner as the arrangement of the conductive fine particles 7 deposited on the surface of the conductive fine particles 7 and the CTL 6, the conductive fine particles 7 and the photosensitive layer 4 that are separately dispersed in the photosensitive layer 4 without the charge injection layer 18. It is also possible to arrange the conductive fine particles 7 deposited on the surface.

  The image forming apparatus and the image forming method of the present invention can be suitably used for an image forming apparatus and an image forming method for forming an electrostatic latent image on an image carrier such as an electrophotographic, electrostatic copying machine, printer, or facsimile. it can.

1 is a cross-sectional view schematically and partially showing a first example of an embodiment of an image carrier in an image forming apparatus of the present invention. 1 is a diagram schematically illustrating an example of an image forming apparatus that performs latent image formation by charge writing (charge injection method) to which an image carrier of the present invention is applied. 1 is a diagram schematically illustrating an example of an image forming apparatus that performs latent image formation by optical writing to which an image carrier of the present invention is applied. FIG. 5 is a cross-sectional view schematically and partially showing a second example of an embodiment of an image carrier of the present invention. FIG. 6 is a cross-sectional view schematically and partially showing a third example of an embodiment of an image carrier of the present invention. It is a cross-sectional view schematically and partially showing a fourth example of an embodiment of an image carrier of the present invention. FIG. 10 is a cross-sectional view schematically and partially showing a fifth example of an embodiment of an image carrier of the present invention. It is a cross-sectional view schematically and partially showing a sixth example of an embodiment of an image carrier of the present invention. FIG. 10 is a cross-sectional view schematically and partially showing a seventh example of an embodiment of an image carrier of the present invention. It is a transverse cross section showing typically and partially an 8th example of an embodiment of an image carrier of the present invention. It is a cross-sectional view schematically and partially showing a ninth example of an embodiment of an image carrier of the present invention. It is a transverse cross section showing typically and partially a 10th example of an embodiment of an image carrier of the present invention. It is a cross-sectional view schematically and partially showing an eleventh example of the embodiment of the image bearing member of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image carrier, 2 ... Base material, 3 ... Undercoat layer (UCL), 4 ... Photosensitive layer, 5 ... Charge generation layer (CGL), 6 ... Charge transport layer (CVL), 7 ... Conductive fine particle, 8 DESCRIPTION OF SYMBOLS ... Charge injection prevention layer (CPL), 9 ... Image forming apparatus, 10 ... Writing head, 11 ... Flexible base material, 12 ... Developing device, 12a ... Developing roller, 13 ... Transfer device, 13a ... Transfer roller, DESCRIPTION OF SYMBOLS 14 ... Charging apparatus, 15 ... Exposure apparatus, 16 ... Binder resin, 17 ... Photoconductive fine particle, 18 ... Charge injection layer, 19 ... Binder resin, 20 ... Conductive fine particle

Claims (11)

In an image carrier used in an image forming apparatus, a photosensitive layer is formed on a conductive substrate and a charge injection layer is formed on the photosensitive layer.
An image carrier in an image forming apparatus, wherein the photosensitive layer contains a large number of conductive fine particles that are independently dispersed. A number of conductive fine particles are independently dispersed and contained in the charge injection layer, and a part of the conductive fine particles of the charge injection layer is deposited on the surface of the charge injection layer. An image carrier in the image forming apparatus according to Item 1. The photosensitive layer is a photosensitive layer formed by laminating a charge generation layer on a conductive base material and a charge transport layer on the charge generation layer. 3. The image carrier in an image forming apparatus according to claim 1, wherein the fine particles are dispersed independently in the circumferential direction and the film thickness direction. In an image carrier used in an image forming apparatus and having a photosensitive layer formed on a conductive substrate,
The photosensitive layer is a photosensitive layer formed by laminating a charge generation layer on a conductive base material and a charge transport layer on the charge generation layer. An image forming apparatus characterized in that fine particles are separately dispersed in the circumferential direction and the film thickness direction, and a part of the conductive fine particles of the charge transport layer is deposited on the surface of the charge transport layer. The image carrier in FIG. The content of the conductive fine particles on the surface layer side of the charge transport layer is high, and the content of the conductive fine particles on the base material side of the charge transport layer is set low. 5. An image carrier in the image forming apparatus according to 3 or 4. 5. The charge transport layer is composed of an upper layer on the surface layer side containing the conductive fine particles and a lower layer on the base material side not containing the conductive fine particles. An image carrier in the image forming apparatus. 5. The content of the conductive fine particles in the charge transport layer is set so as to decrease continuously or in a plurality of stages from the surface layer side toward the base material side. An image carrier in the image forming apparatus. In a single-layer image carrier used in an image forming apparatus, in which a photosensitive layer having a charge generation function and a charge transport function is formed on a conductive substrate,
The photosensitive layer contains a large number of conductive fine particles that are independently dispersed in the circumferential direction and the film thickness direction, and a part of the conductive fine particles of the photosensitive layer is deposited on the surface of the photosensitive layer. An image carrier in an image forming apparatus. 9. The content of the conductive fine particles on the surface layer side of the photosensitive layer is set high, and the content of the conductive fine particles on the substrate side of the photosensitive layer is set low. An image carrier in the image forming apparatus. 9. The image according to claim 8, wherein the photosensitive layer includes an upper layer on the surface layer side containing the conductive fine particles and a lower layer on the base material side not containing the conductive fine particles. An image carrier in the forming apparatus. 9. The image according to claim 8, wherein the content of the conductive fine particles in the photosensitive layer is set so as to decrease continuously or in a plurality of stages from the surface layer side toward the base material side. An image carrier in the forming apparatus.

Images