Abstract: An image forming apparatus includes a transfer belt unit which has an intermediate transfer belt for supporting toner images and primary transfer rollers for pressing the intermediate transfer belt against corresponding photoreceptor drums and moves the intermediate transfer belt along the surface of each photoreceptor drum to transfer the toner images to the intermediate transfer belt. The intermediate transfer belt is formed so as to be 30 ?m to 50 ?m in average thickness, each primary transfer roller is arranged at a position, along the moving direction of the intermediate transfer belt, which is deviated downstream with respect to the moving direction from the position where the intermediate transfer belt is in contact with the photoreceptor and which is projected toward the photoreceptor drum side so as to press the intermediate transfer belt against photoreceptor with a nip pressure ranging from 10 gf/cm2 to 40 gf/cm2.

Abstract: A method for producing a high-quality and low-cost laminate type electrophotographic photoreceptor having a coating film of uniform thickness with high efficiency is provided. In the electrophotographic photoreceptor having a laminated structure composed at least of two layers: a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance, the charge generating layer is formed by applying a coating solution for forming the charge generating layer onto the conductive support by an ink-jet coating method, and the charge transporting layer is formed by applying a coating solution for forming the charge transporting layer onto the charge generating layer by a roll coating method.

Abstract: An image forming apparatus having excellent cleaning property for an electrophotographic photoreceptor and capable of forming a high-quality, high-resolution image. A surface free energy (?) of a photoreceptor (2), which is provided in the image forming apparatus (1), is set to 20 to 35 mN/m. A volume average diameter of toner particles included in a developer stored in a developing unit (29) to develop an electrostatic latent image and form a toner image is set to 4-7 ?m When ? of the photoreceptor (2) is set to within a small range as the particle size of toner is reduced, even small-particle-size toner having increased specific surface area and largely affected by a inter-molecular force is limited in adhesion to the surface of the photoreceptor (2) to provide a good cleaning property and a high-quality image can be formed.

Abstract: An image forming apparatus includes a transfer belt unit which has an intermediate transfer belt for supporting toner images and primary transfer rollers for pressing the intermediate transfer belt against corresponding photoreceptor drums and moves the intermediate transfer belt along the surface of each photoreceptor drum to transfer the toner images to the intermediate transfer belt. The intermediate transfer belt is formed so as to be 30 ?m to 50 ?m in average thickness, each primary transfer roller is arranged at a position, along the moving direction of the intermediate transfer belt, which is deviated downstream with respect to the moving direction from the position where the intermediate transfer belt is in contact with the photoreceptor and which is projected toward the photoreceptor drum side so as to press the intermediate transfer belt against photoreceptor with a nip pressure ranging from 10 gf/cm2 to 40 gf/cm2.

Abstract: An image forming apparatus having excellent chargeability, sensitivity and light responsivity of an electrophotographic photoconductor and capable of forming images of high quality and high resolution at a high speed in various circumstances, is provided. An electrophotographic photoconductor having a photosensitive layer containing the enamine compound represented by the following general formula (1), for example, the enamine compound represented by the following structural formula (1-1) as a charge transportation substance is mounted to an image forming apparatus and the volume average particle size of the toner contained in a developer 50 housed in a developing device 33 is set to a size from 4 to 7 ?m.

Abstract: An object of the invention is to provide an image forming apparatus being excellent in cleaning property for an electrophotographic photoreceptor and capable of forming a high-quality, high-resolution image. A surface free energy (?) of a photoreceptor (2) which is provided in the image forming apparatus (1) and is exposed to a light corresponding to image information for formation of an electrostatic latent image is set to 20 to 35 mN/m. A volume average diameter of a toner particles included in a developer stored in a developing unit (29) to develop an electrostatic latent image and form a toner image is set to 4-7 mum.

Abstract: The object of the invention is to prevent interference fringes of images and allow precise measurement of the thickness of a layer by the optical interferometry by limiting the surface roughness of a conductive substrate. The surface roughness of the conductive substrate provided in an electrophotographic photoreceptor is such that the maximum peak-to-valley roughness height (Ry)=0.8 to 1.4 ?m, the centerline average roughness (Ra)=0.10 to 0.15 ?m, the ten-point average roughness (Rz)=0.7 to 1.3 ?m, the average peak-to-peak distance (Sm)=5 to 30 ?m, and the peak count Pc=60 to 100. In such an electrophotographic photoreceptor, light for exposure can be scattered to an appropriate extent, so that interference fringes can be prevented, and an interference pattern is formed during measurement of the thickness of the photosensitive layer by the optical interferometry so that the thickness of the layer can be measured with a high precision.

Abstract: In an electrophotographic photoreceptor including a conductive substrate and a photoreceptive layer formed on the conductive substrate wherein the photoreceptive layer charged uniformly is exposed to light corresponding to an image information to form an electrostatic latent image, the surface free energy (?) is determined to be at least 20 mN/m and at most 35 mN/m. The determination of ? on the surface of the photoreceptor 1 in the appropriate range makes it possible to suppress excessive adhesion of a toner to the surface of the photoreceptor, to suppress adhesion of foreign matters such as a paper powder and to make easy the separation thereof from the surface, which results in improving the cleanability of the photoreceptor. Since the image is formed with the photoreceptor 1 having always the clean surface, the damage or the decrease in image quality does not occur over a long period of time.

Abstract: A method for producing a high-quality and low-cost laminate type electrophotographic photoreceptor having a coating film of uniform thickness with high efficiency is provided. In the electrophotographic photoreceptor having a laminated structure composed at least of two layers: a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance, the charge generating layer is formed by applying a coating solution for forming the charge generating layer onto the conductive supportby an ink-jet coating method, and the charge transporting layer is formed by applying a coating solution for forming the charge transporting layer onto the charge generating layer by a roll coating method.

Abstract: An image forming apparatus having excellent chargeability, sensitivity and light responsivity of an electrophotographic photoconductor and capable of forming images of high quality and high resolution at a high speed in various circumstances, is provided. An electrophotographic photoconductor having a photosensitive layer containing the enamine compound represented by the following general formula (1), for example, the enamine compound represented by the following structural formula (1-1) as a charge transportation substance is mounted to an image forming apparatus and the volume average particle size of the toner contained in a developer 50 housed in a developing device 33 is set to a size from 4 to 7 ?m.

Abstract: A vibration insulating member fitting method includes the steps of: positioning and wrapping a sheet-like vibration insulating member 2 around a shaft 3 having an air suction/exhaust portion 5; holding the sheet-like vibration insulating member 2 onto the shaft 3 by air suction; and inserting the shaft 3 that sucks the sheet-like vibration insulating member 2 by the air suction into a hollow cylinder 13 of a photosensitive drum 1 to stop the air suction, causing the sheet-like vibration insulating member 2 to be tightly fitted onto the inner wall surface of the photosensitive drum 1 by a restoring force of the sheet-like vibration insulating member 2.

Abstract: In the present invention, a filler element 20 formed of a viscoelastic material with a compressive residual strain of 10% or less and a 25% compressive load of 1 kg/cm2, having a specific shape, is mounted in a drum-shaped electrophotographic photosensitive body (photosensitive drum) 10. The filler element 20 has a sufficient restoring force when deformed, so that it can be fixed to position without an adhesive. Also, the filler element 20 is not moved by vibration or shock during repeated use, and good anti-vibration effect can be maintained.

Abstract: In an electrophotographic photoreceptor including a conductive substrate and a photoreceptive layer formed on the conductive substrate wherein the photoreceptive layer charged uniformly is exposed to light corresponding to an image information to form an electrostatic latent image, the surface free energy (&ggr;) is determined to be at least 20 mN/m and at most 35 mN/m. The determination of &ggr; on the surface of the photoreceptor 1 in the appropriate range makes it possible to suppress excessive adhesion of a toner to the surface of the photoreceptor, to suppress adhesion of foreign matters such as a paper powder and to make easy the separation thereof from the surface, which results in improving the cleanability of the photoreceptor. Since the image is formed with the photoreceptor 1 having always the clean surface, the damage or the decrease in image quality does not occur over a long period of time.

Abstract: The object of the invention is to prevent interference fringes of images and allow precise measurement of the thickness of a layer by the optical interferometry by limiting the surface roughness of a conductive substrate. The surface roughness of the conductive substrate provided in an electrophotographic photoreceptor is such that the maximum peak-to-valley roughness height (Ry)=0.8 to 1.4 &mgr;m, the centerline average roughness (Ra)=0.10 to 0.15 &mgr;m, the ten-point average roughness (Rz)=0.7 to 1.3 &mgr;m, the average peak-to-peak distance (Sm)=5 to 30 &mgr;m, and the peak count Pc=60 to 100. In such an electrophotographic photoreceptor, light for exposure can be scattered to an appropriate extent, so that interference fringes can be prevented, and an interference pattern is formed during measurement of the thickness of the photosensitive layer by the optical interferometry so that the thickness of the layer can be measured with a high precision.

Abstract: The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect.

Abstract: A vibration insulating member fitting method includes the steps of: positioning and wrapping a sheet-like vibration insulating member 2 around a shaft 3 having an air suction/exhaust portion 5; holding the sheet-like vibration insulating member 2 onto the shaft 3 by air suction; and inserting the shaft 3 that sucks the sheet-like vibration insulating member 2 by the air suction into a hollow cylinder 13 of a photosensitive drum 1 to stop the air suction, causing the sheet-like vibration insulating member 2 to be tightly fitted onto the inner wall surface of the photosensitive drum 1 by a restoring force of the sheet-like vibration insulating member 2.

Abstract: In the present invention, a filler element 20 formed of a viscoelastic material with a compressive residual strain of 10% or less and a 25% compressive load of 1 kg/cm2, having a specific shape, is mounted in a drum-shaped electrophotographic photosensitive body (photosensitive drum) 10. The filler element 20 has a sufficient restoring force when deformed, so that it can be fixed to position without an adhesive. Also, the filler element 20 is not moved by vibration or shock during repeated use, and good anti-vibration effect can be maintained.

Abstract: The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect.

Abstract: An organic electrophotographic receptor comprising at least an undercoating layer, an electric charge generating layer, and an electric charge transferring layer which are laminated in said order, wherein a coating fluid 5 for forming said electric charge generating layer comprising an electric charge generating material, a binding resin, a silicon oil having a surface tension of 22 mN/m or less, and an organic solvent is stored inside a tank 4, and a photosensitive base 1 supported by a chucking device 8 is dipped into said coating tank 4 so as to form said electric charge generating layer.

Abstract: An organic electrophotographic receptor comprising at least an undercoating layer, an electric charge generating layer, and an electric charge transferring layer which are laminated in said order, wherein a coating fluid 5 for forming said electric charge generating layer comprising an electric charge generating material, a binding resin, a silicon oil having a surface tension of 22 mN/m or less, and an organic solvent is stored inside a tank 4, and a photosensitive base 1 supported by a chucking device 8 is dipped into said coating tank 4 so as to form said electric charge generating layer.