Abstract: The invention provides an image forming apparatus comprising at least: an electrophotographic photoreceptor comprising at least a conductive substrate and a photosensitive layer provided on the conductive substrate; a charging device; an exposure device; a developing device; and a transfer device, wherein the exposure device is of a multi beam exposure system which has a surface emitting laser array having two or more light-emitting elements as an exposure light source and which scan the electrophotographic photoreceptor with plural light beams thereby forming electrostatic latent image, and wherein the outermost layer in the electrophotographic photoreceptor, positioned most distant from the conductive substrate, contains a silicon-containing resin containing at least a charge transporting compound or a characteristic group derived from a charge transporting compound, and having a structure in which bonds formed by crosslinking of an O atom with neighboring Si atoms are formed three dimensionally.

Abstract: An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer disposed on the conductive support, wherein the photosensitive layer comprises a silicon compound-containing layer containing a silicon compound, and the silicon compound-containing layer further contains a resin, and wherein the photosensitive layer has a peak area in the region of −40 to 0 ppm (S1) and a peak area in the region of −100 to −50 ppm (S2) in a 29Si-NMR spectrum satisfying the following equation (1):

Abstract: An image forming apparatus comprising: an electrophotographic photoreceptor having an electrically-conductive support and a photosensitive layer provided on said support; an electrostatic charging unit for electrostatically charging said electrophotographic photoreceptor; an exposing unit for exposing said electrostatically charged electrophotographic photoreceptor to light to form an electrostatic latent image; a developing unit for developing said electrostatic latent image with a toner to form a toner image; a transferring unit for transferring said toner image onto a transferring medium; and a cleaning device for removing a toner left on said electrophotographic photoreceptor after the transfer of said toner image, wherein said image forming apparatus is capable of performing image formation at a processing speed of not lower than 150 mm/s, wherein said electrophotographic photoreceptor comprises a surface layer containing a siloxane-based resin having charge-transporting properties and a crosslinked stru

Abstract: Provided are a photoreceptor of an electophotographic system satisfactorily high in resistance to contamination with a developer or corona products and durability to a contact electrification unit or a cleaning blade and capable of preventing occurrence of film defects in the production, and a process cartridge and an image forming apparatus in which a good image quality can be obtained over a long period of time. The photoreceptor includes a conductive substrate and a silicon compound-containing layer located on the substrate and containing a cyclic siloxane compound and/or derivatives thereof.

Abstract: An apparatus for forming an image is provided that can sufficiently prevent occurrence of nibbled images without any damage of the photoreceptor and the intermediate transfer body, whereby good image quality can be stably obtained for a long period of time. In an apparatus for forming an image having an intermediate transfer body, the surface of the photoreceptor has a dynamic hardness of 8×109 N/m2 or more, and the surface of the intermediate transfer body has a dynamic hardness larger than that of the surface of the photoreceptor, and a difference between the dynamic hardness of the surface of the photoreceptor and the dynamic hardness of the surface of the intermediate transfer material is 2×1010 N/m2 or less.

Abstract: An electrophotographic photoreceptor that can sufficiently prevent occurrence of filming, whereby defects on an image can be sufficiently prevented, and an electrophotographic process cartridge and an electrophotographic apparatus using the electrophotographic photoreceptor are to be provided. The electrophotographic photoreceptor contains an electroconductive substrate having provided thereon a photosensitive layer, and an outermost layer of the photosensitive layer has a dynamic hardness of about from 13.0×109 to 100.0×109 N/m2. According to the invention, occurrence of flaws on the surface of the photoreceptor can be sufficiently prevented, and cracking of a member made in contact with the photoreceptor can also be sufficiently prevented. Therefore, occurrence of filming is sufficiently prevented, and occurrence of defects on an image is also sufficiently prevented.

Abstract: A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.

Abstract: A process for producing an electrophotographic photoreceptor, which includes contacting a solution containing at least one of optically functional organosilicon compounds represented by formula (I) F—[D—A]b  (I) with a solid catalyst for reaction, then separating the solid catalyst to form an optically functional coating solution, and coating and curing the optically functional coating solution to form a cured film, an electrophotographic photoreceptor having at least one layer made of the cured film produced by this process, and an image-forming apparatus having the same.

Abstract: An electrophotographic photoreceptor comprising an electrically-conductive substrate having thereon at least a photosensitive layer and a surface protective layer: wherein the surface protective layer has a network structure formed by the reaction of hydroxyl group-containing compounds with an isocyanate group-containing compound; and wherein at least one of the hydroxyl group-containing compounds is an electric charge-transporting material containing a hydroxyl group. Also disclosed are a preparation process of the electrophotographic photoreceptor and an image forming apparatus comprising the electrophotographic photoreceptor.

Abstract: A charging roll fit for use at high speed, having good maintaining property of charging characteristics in long-term use, stable in electric resistance under the environmental conditions, and having no fear of pinhole leak and photoreceptor contamination, which comprises a conductive shaft and a conductive layer formed thereon, wherein said conductive layer contains a layer in which SnO.sub.2-x -coated BaSO.sub.4 particles having an electric resistance of 0.1 to 10 .OMEGA..multidot.cm are dispersed in a resin, and the value of x is 0 to 1.

Abstract: A charge roll for electrophotography wherein surface of the roll is formed from a resin layer containing BaSO.sub.4 particles coated with SnO.sub.2-x (wherein 0.ltoreq.X.ltoreq.1) is disclosed. The charge roll may comprise a roll shaft, an electroconductive elastic layer and the surface resin layer. The charge roll may further comprise an intermediate layer formed between the electroconductive elastic layer and the surface resin layer.

Abstract: Crystals of hydroxygallium phthalocyanine, a method of preparing the crystals, a photoconductive material containing the crystals, and an electrophotographic photoreceptor having the material. The photoreceptor has excellent electrophotographic characteristics. The crystals of hydroxygallium phthalocyanine have distinct diffraction peaks at (i) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree., or (ii) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., or (iii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., or (iv) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree. and 27.1.degree., or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. or (vi) 7.4.degree., 9.9.degree., 25.0.degree., 26.0.degree., and 28.2.degree. of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction spectrum.