Patents by Inventor Nobuo Inagaki
Nobuo Inagaki 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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Patent number: 4915717Abstract: An improved method for fabricating an optical fiber preform by the vapor phase axial deposition (VAD) method, comprises forming core and cladding soots at the same time by the use of core and cladding burners. The improvement is that the cladding burner is designed so that at least one of the outlets for a feed material gas, a fuel gas, an auxiliary fuel gas, and an inert gas is composed of a plurality of openings. In this improved method, the temperature distribution from the boundary of the core soot to the periphery of the cladding soot is made smooth, and thus the cladding soot is prevented from cracking.Type: GrantFiled: February 6, 1984Date of Patent: April 10, 1990Assignees: Tokyo Nippon Telegraph Public Corporation, Sumitomo Electric Industries, Ltd.Inventors: Minoru Watanabe, Naoki Yoshioka, Hiroo Kanamori, Nobuo Inagaki
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Patent number: 4639080Abstract: A coating material for optical glass fibers is disclosed. The material is comprised of 1,4-polybutadienes having functional groups or modified polybutadienes derived from the 1,4-polybutadienes having introduced therein polymerizable double bonds different from the double bonds present in the 1,4-polybutadienes.Type: GrantFiled: August 28, 1984Date of Patent: January 27, 1987Assignees: Nippon Telegraph & Telephone Public Corporation, Nitto Electric Industrial Co., Ltd.Inventors: Takao Kimura, Nobuo Inagaki, Mitsuo Yoshihara, Fumihiko Kato
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Patent number: 4586943Abstract: A method for producing a glass preform for optical fibers by heating a glass soot preform consisting of glass fine particles made mainly of silicon oxide, which method comprises the steps of:(1) heating the glass soot preform to dehydrate and to remove impurities therefrom;(2) heating the glass soot preform in a gas atmosphere containing at least fluorine or fluorine-based compound to add fluorine to the glass soot preform; and(3) heating the glass soot preform to make it transparent, from the transparent preform prepared by which method, an optical fiber having superior transmission characteristics can be prepared.Type: GrantFiled: October 16, 1984Date of Patent: May 6, 1986Assignees: Sumitomo Electric Industries, Ltd., Nippon Telegraph & Telephone Public CorporationInventors: Michihisa Kyoto, Naoki Yoshioka, Gotaro Tanaka, Minoru Watanabe, Hiroshi Shimba, Nobuo Inagaki
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Patent number: 4552576Abstract: A method of fabricating an optical glass base material by injecting and depositing fine glass particles produced by chemically reacting glass stock which comprises means for growing the fine glass particles in a depositing direction to form porous rod-shaped base material, support means for supporting the porous rod-shaped base material after growing, and heat treatment means for sintering at least the outer periphery of the rod-shaped base material in a semisintering state before supporting the rod-shaped base material by said support means to harden the same. Thus, since the rod-shaped base material is held in the stable state through the support means, the mechanical strength of the base material is strengthened strength by the semisintering hardening through the heat treating means before being supported by the support means, the base material is not deformed nor damaged in the supported state, and a large base material may be fabricated.Type: GrantFiled: August 20, 1984Date of Patent: November 12, 1985Assignees: The Furukawa Electric Co., Ltd., Nippon Telephone & Telegraph Public Corp.Inventors: Ryoichi Hara, Toshiaki Kuroha, Nobuo Inagaki
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Patent number: 4528010Abstract: A process for producing an optical glass product having a predetermined distribution of refractive index in the interior of the product is disclosed. The process comprises the steps of:(a) preparing an aqueous silicate solution containing from about 0.1 to about 0.6 mol/liter of Si (as SiO.sub.2) comprising silicic acid and at least one element selected from the group consisting of rubidium, thallium and cesium;(b) mixing the silicate solution with an acidic aqueous solution, and letting the two solutions react with each other for a period of time sufficient for polymerization to produce a porous gelled product wherein the silica particles are agglomerated;(c) leaching the gelled product with a liquid selected from the group consisting of water, a weakly acidic aqueous solution, an aqueous solution having an alkali metal salt dissolved therein and an aqueous solution of organic matter capable of dissolving Rb.sub.2 O, Cs.sub.2 O, or Tl.sub.Type: GrantFiled: February 29, 1984Date of Patent: July 9, 1985Assignees: Nippon Telegraph & Telephone Public Corporation, Sumitomo Electric IndustriesInventors: Takao Edahiro, Nobuo Inagaki, Shiro Kurosaki
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Patent number: 4414012Abstract: Manufacturing method of doped silica glass suitable for optical fiber wherein quartz powder or SiO.sub.2 glass fine particles are exposed to a gas for producing the doped silica glass containing SiCl.sub.4, a gaseous additive and water vapor (H.sub.2 O) to add the dopant to the glass body, and then the resulting glass body is fused at a high temperature, thereby producing a transparent doped silica glass in which the production of the glass particles, the addition of the dopant, and the vitrification of the glass body are carried out by separate steps under respective suitable conditions. The manufacturing speed is remarkably increased because of the separate steps. The content of the dopant is not limited, but can be adjusted with any desired amount by changing the reaction time of dissolution. Dopant components like PbO.sub.2, SnO.sub.2, ZnO which were typically not added to the glass body can now be added thereto.Type: GrantFiled: September 8, 1981Date of Patent: November 8, 1983Assignee: Nippon Telegraph & Telephone Public CorporationInventors: Shoichi Suto, Hiroyuki Suda, Fumiaki Hanawa, Motohiro Nakahara, Nobuo Inagaki
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Patent number: 4396645Abstract: Coated optical glass fibers are described, wherein the coating composition comprises an unsaturated polyester containing at least one of (1) polyethylene glycol or polypropylene glycol having an average molecular weight of from 200 to 1,000 as a glycol component, (2) a long chain saturated aliphatic dibasic acid containing 12 or more carbon atoms as saturated polybasic acid component, and an acrylate or methacrylate, and (3) a long chain saturated aliphatic dibasic acid containing 6 or more carbon atoms as a saturated polybasic acid component and a long chain aliphatic dihydric alcohol containing 4 or more carbon atoms as a glycol component; and an acrylate or methacrylate.Type: GrantFiled: September 24, 1981Date of Patent: August 2, 1983Assignees: Nippon Telegraph and Telephone Public Corporation, Nitto Electric Industrial Co., Ltd.Inventors: Takao Kimura, Nobuo Inagaki, Mitsuo Yoshihara, Fumihiko Kato
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Patent number: 4232071Abstract: A method of roducing .gamma.-Fe.sub.2 O.sub.3 magnetic disk medium of continuous thin film is provided, in which a deposition source is deposited on an opposed Al-alloy substrate by means of a reactive vacuum deposition technique and the deposited film is thermally treated so as to be the magnetic disk medium. As the deposition source, a ferroalloy containing about 1 to 10 at.% Ti and about 0.5 to 5 at.% Co is employed.Type: GrantFiled: June 29, 1977Date of Patent: November 4, 1980Assignees: Nippon Telegraph and Telephone Public Corporation, Fujitsu LimitedInventors: Akira Terada, Seizi Hattori, Yoshikazu Ishii, Akira Nohara, Nobuo Inagaki, Wakatake Matsuda, Susumu Kawakami
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Patent number: 4013534Abstract: In the process of sputtering of an iron target in an atmosphere composed of a mixed gas containing a rare gas and oxygen, the oxygen partial pressure is regulated prior to both presputtering and main sputtering, by which ferromagnetic oxide Fe.sub.3 O.sub.4 is deposited on a substrate in one process. By setting the temperature of the substrate at 150.degree. to 250.degree. C, the coercive force and the squareness ratio of the oxide film is greatly enhanced. By using the oxide film as a medium of a magnetic disk storage, a magnetic recording and storage device of excellent characteristics can be obtained.Type: GrantFiled: October 14, 1975Date of Patent: March 22, 1977Assignee: Nippon Telegraph and Telephone Public CorporationInventors: Yoshikazu Ishii, Seizi Hattori, Nobuo Inagaki
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Patent number: 4003813Abstract: A magnetic oxide film manufacturing method is disclosed which involves the steps of sputtering a target made of iron and aluminum to form a film of non-magnetic iron oxide (.alpha.-Fe.sub.2 O.sub.3) and reducing the film to obtain a magnetic oxide film. When a target made of iron and aluminum is employed, it is possible to obtain a high coercive force magnetic oxide film which is highly adhesive to a substrate, excellent in surface roughness and less than 0.3.mu.m in thickness. Accordingly, it is possible to obtain a magnetic disk of high magnetic recording density.Type: GrantFiled: August 14, 1975Date of Patent: January 18, 1977Assignee: Nippon Telegraph and Telephone Public CorporationInventors: Seizi Hattori, Nobuo Inagaki, Yoshikazu Ishii