Patents by Inventor Narihito Kojima
Narihito Kojima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20020197549Abstract: An electrophotographic photoreceptor including at least an electroconductive substrate; and a photosensitive layer overlying the electroconductive substrate and including at least a charge generation layer; a charge transport layer; and a protective layer including a filler, wherein the filler is dispersed in the protective layer so as to occupy an area of from 3 to 5% of a cross section of the protective layer; the filler has particle diameter distribution having a peak at a diameter of from 0.2 to 0.3 &mgr;m; and the particles of the filler having a particle diameter of not less than 0.3 &mgr;m occupies an area of from 10 to 30% of the area of all the filler in the cross section of the protective layer.Type: ApplicationFiled: November 2, 2001Publication date: December 26, 2002Inventors: Yohta Sakon, Akio Kosuge, Tatsuya Niimi, Narihito Kojima
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Publication number: 20020115005Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: &sgr;≦D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 &mgr;m wide when a portion of a cross section of the photoreceptor of 100 &mgr;m wide is divided into the 20 segments, and &sgr; represents a standard deviation of the 20 maximum thicknesses.Type: ApplicationFiled: November 2, 2001Publication date: August 22, 2002Inventors: Hiroshi Ikuno, Hidetoshi Kami, Ryohichi Kitajima, Narihito Kojima, Akihiko Matsuyama, Hiroshi Nagame, Katsuichi Ohta, Tetsuro Suzuki, Nozomu Tamoto, Hiroshi Tamura, Yohta Sakon, Eiji Kurimoto, Tatsuya Niimi, Yuka Miyamoto
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Patent number: 6432596Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a charge generation layer overlying the substrate; a charge transport layer formed overlying the substrate and including a charge transport material, a polycarbonate resin, an antioxidant having the following formula (1): and a sulfur-containing compound having an alkyl group having from 6 to 30 carbon atoms; and a protective layer comprising a binder resin and a filler dispersed in the binder resin and formed as a top layer.Type: GrantFiled: April 4, 2001Date of Patent: August 13, 2002Assignee: Ricoh Company LimitedInventors: Hiroshi Ikuno, Narihito Kojima, Eiji Kurimoto
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Patent number: 6363237Abstract: A lubricity-imparting unit for imparting lubricity to a surface of an electrophotographic photoconductor, which is in contact with the surface of the photoconductor, wherein at least a surface of the lubricity-imparting unit which comes into contact with the surface of the photoconductor includes a flexible lubricating material, and has a length at least capable of covering an image formation region of the electrophotographic photoconductor lengthwise. An image formation apparatus and an image formation method using this lubricity-imparting unit are described.Type: GrantFiled: November 11, 1999Date of Patent: March 26, 2002Assignee: Ricoh Company, Ltd.Inventors: Hiroshi Nagame, Narihito Kojima, Yohta Sakon, Ryuta Takeichi, Akiyo Nakajima
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Publication number: 20010051307Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a charge generation layer overlying the substrate; a charge transport layer formed overlying the substrate and including a charge transport material, a polycarbonate resin, an antioxidant having the following formula (1): 1Type: ApplicationFiled: April 4, 2001Publication date: December 13, 2001Applicant: Ricoh Company LimitedInventors: Hiroshi Ikuno, Narihito Kojima, Eiji Kurimoto
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Patent number: 6326112Abstract: An electrophotographic photoreceptor which includes an electroconductive substrate, and a photosensitive layer which is formed overlying the substrate, wherein the photosensitive layer includes a charge generation material, a charge transport polymer material including triarylamine structure and a soft segment in a main chain thereof, and a filler.Type: GrantFiled: August 21, 2000Date of Patent: December 4, 2001Assignee: Ricoh Company LimitedInventors: Hiroshi Tamura, Hidetoshi Kami, Katsuichi Ohta, Tetsuro Suzuki, Tatsuya Niimi, Narihito Kojima
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Publication number: 20010031411Abstract: An electrophotographic photoreceptor including a photosensitive layer on an electroconductive substrate, wherein nitrate ion is present on the surface of the photosensitive layer in an amount of from 50 to 300 &mgr;g per 1 m2 of the surface of the photosensitive layer when the nitrate ion is determined by an ion chromatographic method. Preferably a material having a fluorine atom and a carbon atom or a fatty acid metal salt such as zinc stearate is further present on the surface of the photosensitive layer such that the F/C ratio is from 0.05 to 0.5 or the Zn/C ratio is from 0.001 to 0.1. An image forming apparatus using the photoreceptor is also provided.Type: ApplicationFiled: March 2, 2001Publication date: October 18, 2001Applicant: Ricoh Company LimitedInventors: Narihito Kojima, Ryuta Takeichi, Akiyo Namiki, Hiroshi Nagame, Yohta Sakon
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Patent number: 6160977Abstract: In an image forming apparatus of the type sequentially executing charging, exposure, development and image transfer, a device for applying a lubricant to the surface of an image carrier includes a lubricant applying member rotatable in contact with the image carrier for applying, at a position where the lubricant applying member contacts the image carrier, the lubricant to the surface of the image carrier while deforming its contour in accordance with a bite of the surface of the image carrier. A lubricant feeding unit feeds the lubricant to the lubricant applying member and includes a lubricant providing unit having a preselected thickness t. The surface of the image carrier bites into the lubricant applying member by an amount T while the lubricant providing unit bites into the lubricant applying member by an amount t' smaller than the amount T, but substantially equal to or slightly greater than the thickness t.Type: GrantFiled: November 29, 1999Date of Patent: December 12, 2000Assignee: Ricoh Company, Ltd.Inventors: Ryuta Takeichi, Akiyo Nakajima, Narihito Kojima, Hiroshi Nagame, Yohta Sakon
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Patent number: 6151468Abstract: An electrophotographic photoconductor including a photoconductive layer which is formed overlying an electroconductive substrate and which includes at least a charge transporting polymer material, wherein the photoconductive layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.-2 .multidot.24 h.sup.-1. The photoconductive layer may be a functionally separated photoconductive layer including a charge generating layer and a charge transporting layer which is formed overlying the charge generating layer and which includes the charge transporting polymer material, wherein the charge transporting layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.-2 .multidot.24 h.sup.-1.Type: GrantFiled: November 29, 1999Date of Patent: November 21, 2000Assignee: Ricoh Company, Ltd.Inventors: Hidetoshi Kami, Tetsuro Suzuki, Narihito Kojima, Hiroshi Nagame, Hiroshi Tamura, Yohta Sakon, Hiroshi Ikuno
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Patent number: 6118964Abstract: A charging or image transfer unit for use in an image formation process including the steps of charging, image formation exposure, image development, image transfer, image fixing and cleaning, for applying an electric field to the surface of an electrophotographic photoconductor by coming into contact therewith, and also for controlling surface properties of the electrophotographic photo-conductor. The unit includes an electric field application member applying the electric field to the surface of the electrophotographic photoconductor and a lubricity-imparting member for controlling a friction coefficient of the surface of the electrophotographic photoconductor wherein the electric field application member includes an electrophotoconductive material and a lubricity-imparting member includes a fluoroplastic material.Type: GrantFiled: December 10, 1998Date of Patent: September 12, 2000Assignee: Ricoh Company, Ltd.Inventors: Narihito Kojima, Hiroshi Nagame, Ryuta Takeichi, Yukiko Iwasaki, Akiyo Nakajima, Hiroyuki Fushimi
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Patent number: 6060205Abstract: An image forming apparatus comprising a lubricant supplying device which supplies a lubricant to a rotating image carrier, wherein the lubricant comprises at least one of low molecular weight polytetrafluoroethylene, a fluorine-containing resin including a filler, polytetrafluoroethylene which has been subjected to heat or radiation decomposition treatment, a fluorine-containing resin which has been prepared by a compression molding method, and a porous fluorine-containing resin. The lubricant preferably has a concave portion on the surface thereof contacting the image carrier. The lubricant is preferably disposed so that an acute angle formed by a line parallel to a compression direction of the lubricant, during the compression molding of the lubricant, and a line parallel to a moving direction of the image carrier, is from about 45 to about 90.degree..Type: GrantFiled: April 19, 1999Date of Patent: May 9, 2000Assignee: Ricoh Company, Ltd.Inventors: Ryuta Takeichi, Narihito Kojima, Hiroshi Nagame, Yohta Sakon, Akiyo Nakajima
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Patent number: 6030733Abstract: An electrophotographic photoconductor including a photoconductive layer which is formed overlying an electroconductive substrate and which includes at least a charge transporting polymer material, wherein the photoconductive layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.-2 .multidot.24 h.sup.-1. The photoconductive layer may be a functionally separated photoconductive layer including a charge generating layer and a charge transporting layer which is formed overlying the charge generating layer and which includes the charge transporting polymer material, wherein the charge transporting layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.2 .multidot.24 h.sup.-1.Type: GrantFiled: February 3, 1999Date of Patent: February 29, 2000Assignee: Ricoh Company, Ltd.Inventors: Hidetoshi Kami, Tetsuro Suzuki, Narihito Kojima, Hiroshi Nagame, Hiroshi Tamura, Yohta Sakon, Hiroshi Ikuno
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Patent number: 6014532Abstract: An image forming apparatus capable of adequately adjusting the amount of a low friction agent to be applied to the surface of a photoconductive element in accordance with image quality is disclosed. After preselected initialization, an electrophotographic image forming section records a usual image or a particular image for evaluation on a paper. A toner image formed on the photoconductive element and a toner image transferred from the element to a paper are read. Image data representative of such toner images and the initial image data are compared to see if the read images are defective or not. The low friction agent is applied to the photoconductive element in an amount controlled on the basis of the result of the decision.Type: GrantFiled: November 3, 1998Date of Patent: January 11, 2000Assignee: Ricoh Company, Ltd.Inventors: Ryuta Takeichi, Yukiko Iwasaki, Akiyo Nakajima, Hiroshi Nagame, Narihito Kojima, Hiroyuki Fushimi
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Patent number: 5871876Abstract: An electrophotographic photoconductor has an electroconductive support and a photoconductive layer formed thereon, which contains a charge transport material with a polycarbonate structure having a triarylamino group at least on the main chain or side chain thereof, and a charge generation material with a phthalocyanine skeleton.Type: GrantFiled: May 23, 1997Date of Patent: February 16, 1999Assignee: Ricoh Company, Ltd.Inventors: Hiroshi Ikuno, Hiroshi Nagame, Tetsuro Suzuki, Hidetoshi Kami, Jun Aoto, Hiroshi Tamura, Narihito Kojima, Tatsuya Niimi
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Patent number: 5870657Abstract: A charging apparatus for a photoconductor composed of an electroconductive charging member and mechanism for feeding a voltage to the charging member. This charging apparatus is composed of a material capable of adsorbing ozone. The charging apparatus may be in the form of a roller type, a blade type or the like. Carbon fibers having micro pores can be used as the charging member.Type: GrantFiled: May 5, 1997Date of Patent: February 9, 1999Assignee: Ricoh Company, Ltd.Inventors: Hiroshi Nagame, Narihito Kojima, Hiroshi Ikuno
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Patent number: 5840455Abstract: An electrophotographic photoconductor, having a conductive supporting substrate, a photoconductive layer disposed thereon, and a surface protective layer formed on the photoconductive layer, with the surface protective layer being made of hydrogenated diamond-like carbon or hydrogenated amorphous carbon and containing at least one additional element selected from the group consisting of nitrogen, fluorine, boron, phosphorus, chlorine, bromine and iodine, with the atomic ratio of total additional elements to carbon in the surface protective layer being smaller in close proximity to the photoconductive layer than in the remainder of the surface protective layer, and having a Knoop hardness of more than or equal to 1000 kg/mm.sup.2 in the outermost portion of the surface protective layer is provided which has improved resistance against peeling and scratch, and is thus capable of forming electrophotographic images of high quality for repeated use over an extended period of time.Type: GrantFiled: May 24, 1996Date of Patent: November 24, 1998Assignee: Ricoh Company, Ltd.Inventors: Hiroshi Ikuno, Narihito Kojima, Hiroshi Nagame
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Patent number: 5656406Abstract: An electrophotographic photoconductor includes an electroconductive support; a photoconductive layer formed on the electroconductive support; and a surface protective layer formed on the photoconductive layer, the surface protective layer having a hydrogen-containing diamond-like carbon structure or amorphous carbon structure, which contains at least one additive element selected from the group consisting of nitrogen, fluorine, boron, phosphorus, chlorine, bromine and iodine, with the atomic ratio of the additive element to the carbon in the carbon structure having such a distribution in the direction of the thickness of the surface protective layer that the atomic ratio is smaller in the vicinity of the top surface of the surface protective layer and in the vicinity of the photoconductive layer adjacent to the surface protective layer than in the other portion of the surface protective layer.Type: GrantFiled: January 11, 1995Date of Patent: August 12, 1997Assignees: Ricoh Company, Ltd., Semiconductor Energy Laboratory Co., Ltd.Inventors: Hiroshi Ikuno, Narihito Kojima, Hiroshi Nagame, Shunpei Yamazaki, Shigenori Hayashi
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Patent number: 5540815Abstract: A method of recycling a copy sheet carrying a hydrophobic image thereon by impregnating the sheet with a water-containing separating liquid, causing the to image contact an image separating member, and heating the sheet for thereby transferring the image to the image separating member. The image separating member has a critical surface tension of 25 mN/m or above.Type: GrantFiled: December 9, 1994Date of Patent: July 30, 1996Assignee: Ricoh Company, Ltd.Inventors: Masato Igarashi, Toshiyuki Kawanishi, Eiichi Kawamura, Narihito Kojima
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Patent number: 5525447Abstract: An electrophotographic photoconductor includes an electroconductive support; a photoconductive layer formed on the electroconductive support; and a surface protective layer formed on the photoconductive layer, the surface protective layer having a hydrogen-containing diamond-like carbon structure or amorphous carbon structure, containing therein an additive element selected from the group consisting of nitrogen, fluorine, boron, phosphorous, chlorine, bromine and iodine, with the atomic ratio of the additive element to the carbon contained in the surface protective layer being larger in the vicinity of the top surface of the surface protective layer than in the vicinity of the photoconductive layer adjacent to the surface protective layer.Type: GrantFiled: October 7, 1994Date of Patent: June 11, 1996Assignees: Ricoh Company, Ltd., Semiconductor Energy Laboratory Co., Ltd.Inventors: Hiroshi Ikuno, Narihito Kojima, Hiroshi Nagame, Shunpei Yamazaki, Shigenori Hayashi
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Patent number: 5452061Abstract: An electrophotographic image formation apparatus using a photoconductor which is composed of a substrate, a photoconductive layer provided on the substrate, and a protective layer formed directly or via an intermediate layer on the photoconductive layer and capable of performing an electrophotographic process including the steps of conducting a first charging for uniformly charging the surface of the photoconductor, exposing the charged surface of the photoconductor to light images to form latent electrostatic images corresponding to the light images, developing the latent electrostatic images to toner images, transferring the toner images to a transfer sheet, cleaning the surface of the photoconductor to remove residual toners therefrom, and fixing the toner images to the transfer sheet, includes a charger for charging the photoconductor with a polarity opposite to that of the charge applied in the step of the first charging prior to the step of the first charging.Type: GrantFiled: December 2, 1993Date of Patent: September 19, 1995Assignee: Ricoh Company, Ltd.Inventors: Narihito Kojima, Hiroshi Nagame, Hiroshi Ikuno