Patents by Inventor Masaki Okajima
Masaki Okajima 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: 8038973Abstract: The present invention provides a high purity silicon production system and production method suitable for using inexpensive metallurgical grade metal silicon as a material and using the slag refining method to produce high purity silicon with a purity of 6N or more suitable for solar battery applications, in particular, high purity silicon with a boron content of at least not more than 0.3 mass ppm, inexpensively on an industrial scale, that is, a high purity silicon production system and production method using the slag refining method wherein a direct electromagnetic induction heating means having the function of directly heating the molten silicon in the crucible by electromagnetic induction is arranged outside the outside wall surface of the above crucible and the crucible is formed by an oxidation resistant material at least at a region where the molten silicon contacts the crucible inside wall surface at the time of not powering the direct electromagnetic induction heating means.Type: GrantFiled: July 20, 2006Date of Patent: October 18, 2011Assignee: Nippon Steel Materials Co., Ltd.Inventors: Nobuaki Ito, Kensuke Okazawa, Shinji Tokumaru, Masaki Okajima
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Patent number: 7662356Abstract: The present invention provides a method of refining low purity Si by a slag, in particular removing B, which suppresses wear of the reaction vessel due to the slag and produces high purity Si used for solar battery materials etc. at a low cost, comprising adding SiO2 and an alkali oxide or alkali carbonate as a slag material into molten Si to form a slag during which adding one or more types of materials among materials the same as the reaction vessel material used or ingredients included in the reaction vessel material into the slag so as to remove the impurities in the molten Si.Type: GrantFiled: February 9, 2006Date of Patent: February 16, 2010Assignee: Nippon Steel Materials Co., Ltd.Inventors: Shinji Tokumaru, Kensuke Okazawa, Jirou Kondou, Masaki Okajima
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Publication number: 20090155158Abstract: The present invention provides a high purity silicon production system and production method suitable for using inexpensive metallurgical grade metal silicon as a material and using the slag refining method to produce high purity silicon with a purity of 6N or more suitable for solar battery applications, in particular, high purity silicon with a boron content of at least not more than 0.3 mass ppm, inexpensively on an industrial scale, that is, a high purity silicon production system and production method using the slag refining method wherein a direct electromagnetic induction heating means having the function of directly heating the molten silicon in the crucible by electromagnetic induction is arranged outside the outside wall surface of the above crucible and the crucible is formed by an oxidation resistant material at least at a region where the molten silicon contacts the crucible inside wall surface at the time of not powering the direct electromagnetic induction heating means.Type: ApplicationFiled: July 20, 2006Publication date: June 18, 2009Applicant: NIPPON STEEL MATERIALS COL. LTD.Inventors: Nobuaki Ito, Kensuke Okazawa, Shinji Tokumaru, Masaki Okajima
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Publication number: 20080311020Abstract: An object of the invention is to provide a method for producing a large amount of inexpensive and high purity silicon useful in a solar battery. The method includes steps of preparing molten silicon, preparing a slag, bringing the molten silicon and the slag into contact with each other, and exposing at least the slag to vacuum pressure.Type: ApplicationFiled: February 28, 2006Publication date: December 18, 2008Applicant: NIPPON STEEL MATERIALS CO., LTD.Inventors: Nobuaki Ito, Jiro Kondo, Kensuke Okazawa, Masaki Okajima
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Patent number: 7455822Abstract: A process for production of Si, characterized by adding an oxide, hydroxide, carbonate or fluoride of an alkali metal element, or an oxide, hydroxide, carbonate or fluoride of an alkaline earth metal element, or two or more of such compounds, to solid SiO in a total molar amount of from 1/20 to 1000 times with respect to the moles of solid SiO, heating the mixture at between the melting point of Si and 2000° C. to induce a chemical reaction which produces Si and separating and recovering the Si from the reaction by-product, for the purpose of inexpensively and efficiently producing Si from various forms of solid SiO with no industrial value produced from Si production steps and the like.Type: GrantFiled: July 22, 2003Date of Patent: November 25, 2008Assignee: Nippon Steel CorporationInventors: Jiro Kondo, Masaki Okajima, Shinji Tokumaru, Hitoshi Dohnomae
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Publication number: 20080274031Abstract: The invention relates to a method for producing a great deal of inexpensive high purity silicon useful in a solar battery. Disclosed is a method for producing high purity silicon by removing boron from silicon by oxidization including commencing an oxidization reaction between an oxidizing agent and molten silicon, and cooling at least part of the oxidizing agent during the reaction.Type: ApplicationFiled: February 28, 2006Publication date: November 6, 2008Applicant: NIPPON STEEL MATERIALS CO., LTDInventors: Nobuaki Ito, Jiro Kondo, Kensuke Okazawa, Masaki Okajima
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Publication number: 20080247936Abstract: An object of the present invention is to provide a method for producing a great deal of inexpensive high purity silicon useful in a solar battery. Disclosed is a method for producing the high purity silicon by migrating impurities in molten silicon to slag including the step of feeding an oxidizing agent to the molten silicon together with slag, wherein the oxidizing agent is a material comprising as a primary component at least one of the following materials: alkali metal carbonate, hydrate of alkali metal carbonate, alkali metal hydroxide, alkaline-earth metal carbonate, hydrate of alkaline-earth metal carbonate or alkaline-earth metal hydroxide.Type: ApplicationFiled: February 28, 2006Publication date: October 9, 2008Applicant: NIPPON STEEL MATERIALS CO., LTD.Inventors: Nobuaki Ito, Jiro Kondo, Kensuke Okazawa, Masaki Okajima
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Publication number: 20080145294Abstract: The present invention provides a method of refining low purity Si by a slag, in particular removing B, which suppresses wear of the reaction vessel due to the slag and produces high purity Si used for solar battery materials etc. at a low cost, comprising adding SiO2 and an alkali oxide or alkali carbonate as a slag material into molten Si to form a slag during which adding one or more types of materials among materials the same as the reaction vessel material used or ingredients included in the reaction vessel material into the slag so as to remove the impurities in the molten Si.Type: ApplicationFiled: February 9, 2006Publication date: June 19, 2008Inventors: Shinji Tokumaru, Kensuke Okazawa, Jirou Kondou, Masaki Okajima
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Publication number: 20040247512Abstract: A process for production of Si, characterized by adding an oxide, hydroxide, carbonate or fluoride of an alkali metal element, or an oxide, hydroxide, carbonate or fluoride of an alkaline earth metal element, or two or more of such compounds, to solid SiO in a total molar amount of from {fraction (1/20)} to 1000 times with respect to the moles of solid SiO, heating the mixture at between the melting point of Si and 2000° C. to induce a chemical reaction which produces Si and separating and recovering the Si from the reaction by-product, for the purpose of inexpensively and efficiently producing Si from various forms of solid SiO with no industrial value produced from Si production steps and the like.Type: ApplicationFiled: March 23, 2004Publication date: December 9, 2004Inventors: Jiro Kondo, Masaki Okajima, Shinji Tokumaru, Hitoshi Dohnomae
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Patent number: 5739946Abstract: A novel display device suitable as a portable display device is disclosed. The device includes a pair of substrates and a light modulation layer sandwiched between the substrates. A functional gel is adapted to be deformed by an electric field applied between a pair of electrodes interposed between the substrates, thereby regulating the light incident on the light modulation layer. A high contrast, a high reflectance and a high light utilization are achieved without regard to the angle of visibility.Type: GrantFiled: September 19, 1996Date of Patent: April 14, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Hiroki Iwanaga, Seizaburo Shimizu, Masaki Okajima, Masayuki Saito, Atsushi Sugahara, Kazuyuki Sunohara, Aira Hotta
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Patent number: 5406574Abstract: A semiconductor laser device includes a substrate, a first cladding layer formed on the substrate, an active layer formed on the first cladding layer, and a second cladding layer formed on the active layer having a conductivity type different from that of the first cladding layer, wherein at least one of the first and second cladding layers has a multiquantum barrier structure. The width of the first quantum barrier of the multiquantum barrier structure relative to the side of the active layer is 24 to 100 nm, the width of the second quantum barrier of the multiquantum barrier structure relative to the side of the active layer is 5 to 20 nm, and the multiquantum barrier structure is constituted by alternately stacking first thin layers consisting of In.sub.z (Ga.sub.1-x Al.sub.x).sub.1-z P (x is 0.7 to 1.0 and z is 0 to 1.0) and second thin layers consisting of In.sub.z (Ga.sub.1-y Al.sub.y).sub.1-z P (y is 0 to 0.3 and z is 0 to 1.0).Type: GrantFiled: December 14, 1993Date of Patent: April 11, 1995Assignee: Kabushiki Kaisha ToshibaInventors: John Rennie, Masaki Okajima, Genichi Hatakoshi
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Patent number: 5377291Abstract: A wavelength converting optical device includes an optical waveguide which has a waveguide portion and a cladding portion, at least one of which is formed of a nonlinear optical material. A fundamental wave, incident on the waveguide portion from an input end face of the waveguide, is converted into an optical second harmonic wave by Cerenkov radiation and is radiated into the cladding portion. The radiated second harmonic wave is output from an output end face of the waveguide. A reflecting film is provided on the emerging end face of the waveguide. The reflecting film includes a high reflectivity with respect to the fundamental wave of a guide mode and a low reflectivity with respect to the optical second harmonic wave. A wave front converting element is arranged to oppose the reflecting film. The converting element has a diffraction grating for converting the second harmonic wave, emerging from the output end face of the waveguide, into a plane wave.Type: GrantFiled: December 15, 1989Date of Patent: December 27, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Genichi Hatakoshi, Masaki Okajima, Kazutaka Terashima, Yutaka Uematsu
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Patent number: 5305341Abstract: According to this invention, in a semiconductor laser, an n-type InGaAlP cladding layer, an InGaP active layer, and a p-type InGaAlP cladding layer are sequentially grown on an n-type GaAs substrate to form a double hetero structure. The active layer is constituted by an ordered structure having regularity in the <111> directions, and the p-type cladding layer is constituted by a disordered structure. Band discontinuity in conduction band between the active layer and the p-type cladding layer is increased to improve the temperature characteristics of the laser.Type: GrantFiled: February 19, 1992Date of Patent: April 19, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Yukie Nishikawa, Koichi Nitta, Genichi Hatakoshi, Masaki Okajima, Minoru Watanabe, Kazuhiko Itaya
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Patent number: 5282218Abstract: A semiconductor laser device for radiating a laser beam from a double heterostructure section in which injected carriers having an energy source of the laser beam are confined consists of a compound semiconductor substrate with a prescribed lattice constant for loading the double heterostructure section, a lattice mismatched active layer with a first lattice constant which is 0.5% to 2.0% larger than the lattice constant of the substrate in the double heterostructure section for radiating the laser beam, a lattice mismatched cladding layer with a second lattice constant which is 0.2% to 2.0% smaller than the lattice constant of the substrate for confining the injected carriers in the active layer, and a cladding layer for confining the injected carriers in the active layer by co-operating with the lattice mismatched cladding layer.Type: GrantFiled: June 9, 1992Date of Patent: January 25, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Masaki Okajima, Koichi Nitta, Genichi Hatakoshi, Yukie Nishikawa, Kazuhiko Itaya
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Patent number: 5202895Abstract: A semiconductor laser device comprises a compound semiconductor substrate, a first cladding layer formed on the substrate, an active layer formed on the first cladding layer, made of In.sub.1-y (Ga.sub.1-x Al.sub.x).sub.y P material (0.ltoreq.x<1, 0.ltoreq.y<1), and a second cladding layer formed on the active layer. These first cladding layer, the active layer, and the second cladding layer forms a double heterostructure. A lattice constant of the active layer is larger than that of the substrate by 0.3% or more. The lattice constants of the first and second cladding layers are substantially equal to that of the substrate.Type: GrantFiled: May 3, 1991Date of Patent: April 13, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Nitta, Masayuki Ishikawa, Yukie Nishikawa, Hideto Sugawara, Minoru Watanabe, Masaki Okajima, Genichi Hatakoshi
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Patent number: 5065404Abstract: A visible-light wavelength continuous oscillation laser is disclosed which has an N type GaAs substrate, an N type GaAlAs cladding layer formed on the substrate, and a non-doped GaAlAs active layer formed on the cladding layer. The laser further includes two N type GaAlAs layers, a P type GaAlAs optical guide layer, a P type cladding layer consisting of upper and lower portions, and a ridge section. The N type GaAlAs layers contact both sides of the ridge section. The optical guide layer is sandwiched between the upper and lower portions of the P type cladding layer, is located within the ridge section, and has a refractive index greater than that of the P type cladding layer. The distance between the active layer and the optical guide layer does not depend on the condition in which etching is performed to form the ridge section, but depends basically on the time required to grow crystal.Type: GrantFiled: July 12, 1990Date of Patent: November 12, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Masaki Okajima, Genichi Hatakoshi, Masayuki Ishikawa, Yutaka Uematsu, Nawoto Motegi
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Patent number: 5058120Abstract: A visible light emitting semiconductor laser has a double-heterostructure section above the N-type GaAs substrate, which is composed of a nondoped InGaP active layer sandwiched between an N type InGaAlP cladding layer and a P type InGaAlP cladding layer. A P type InGaP thin-film layer formed on the P type cladding layer functions as an etching stopper. Formed sequentially on the etching stopper layer are a P type cladding layer and an N type GaAs current-blocking layer, which have a stripe-shaped groove section in and around their central portion. The groove section has an opening at the top and the bottom portion narrower than the opening, presenting an inverse-trapezoidal cross-sectional profile. This arrangement makes the width of the optical confinement region of the semiconductor laser narrower than that of the current injection region.Type: GrantFiled: December 27, 1990Date of Patent: October 15, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Nitta, Yukio Watanabe, Yukie Nishikawa, Masaki Okajima, Genichi Hatakoshi
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Patent number: 4799228Abstract: A semiconductor laser diode includes two semiconductive cladding layers of different conductivity types, which are stacked on a substrate. An active layer of an undoped semiconductor film is sandwiched between the cladding layers. A channel groove is formed in a current blocking layer and the underlying cladding layer, to be deep enough to cause the current blocking layer to be divided into two parts. A waveguide layer covers the channel groove and the current-blocking layer, to provide a slab-coupled waveguide structure for transverse mode oscillation. The second cladding layer, the current-blocking layer, and the waveguide layer are composed of gallium arsenide containing aluminum.Type: GrantFiled: August 21, 1986Date of Patent: January 17, 1989Assignee: Kabushiki Kaisha ToshibaInventors: Hiroko Nagasaka, Gen-ichi Hatakoshi, Naohiro Shimada, Motoyuki Yamamoto, Masaki Okajima, Yoshio Iizuka, Hatsumi Kawata, Hideaki Kinoshita, Nobuyuki Matsuura
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Patent number: 4730925Abstract: Oxygen or a mixed gas containing oxygen, or a chemical flame produced by a mixture of a combustion gas and a combustion-assisting gas containing oxygen, is blown against the surface of molten iron to cause radiation emission. The radiations are divided into components of different wavelengths, and the resulting emission spectra are measured to determine the composition of the molten iron.Type: GrantFiled: September 9, 1986Date of Patent: March 15, 1988Assignee: Nippon Steel CorporationInventors: Koichi Chiba, Akihiro Ono, Takamasa Ohno, Masaki Okajima, Hiroshi Yamane, Minoru Hayata
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Patent number: D1021148Type: GrantFiled: November 17, 2021Date of Patent: April 2, 2024Assignee: SEKISUI CHEMICAL CO., LTD.Inventors: Moyuru Okajima, Kouhei Yamaguchi, Koji Kido, Masaki Yamamoto, Sho Fujioka