Patents by Inventor Katsubumi Nagasu
Katsubumi Nagasu 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: 10995030Abstract: A manufacturing method of an optical fiber preform used to produce an optical fiber includes: etching a surface of a core preform that forms a core of the optical fiber with a plasma flame in a chamber; obtaining a porous preform by depositing glass particles on an etched surface of the core preform to form an outside vapor-deposited layer that forms a cladding of the optical fiber in a state where the core preform is put into the chamber; and heating and sintering the porous preform. When obtaining the porous preform, the outside vapor-deposited layer is formed by repeatedly performing the deposition of the glass particles multiple times through supply of source material gas. In a first deposition among the multiple times of deposition of the glass particles, a flow rate of the source material gas is less than or equal to 50% of a stable value.Type: GrantFiled: April 22, 2019Date of Patent: May 4, 2021Assignee: Fujikura Ltd.Inventor: Katsubumi Nagasu
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Patent number: 10578796Abstract: An optical fiber includes: a core; a cladding layer that is lower in refractive index than the core; and a depressed layer that lies between the core and the cladding layer and that is lower in refractive index than the cladding layer, wherein: the optical fiber has an effective core area Aeff that is equal to or greater than 100 ?m2 and equal to or less than 129 ?m2, the core has a radius r1 that is equal to or greater than 5.2 ?m and equal to or less than 7.4 ?m, the core has a refractive index volume Vcore that is equal to or greater than 8.5% ?m2 and equal to or less than 16.5% ?m2, the depressed layer has a refractive index volume Vdep that is equal to or greater than ?40% ?m2 and less than 0% ?m2.Type: GrantFiled: March 29, 2017Date of Patent: March 3, 2020Assignee: Fujikura Ltd.Inventors: Katsubumi Nagasu, Ryo Maruyama
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Publication number: 20190248695Abstract: A manufacturing method of an optical fiber preform used to produce an optical fiber includes: etching a surface of a core preform that forms a core of the optical fiber with a plasma flame in a chamber; obtaining a porous preform by depositing glass particles on an etched surface of the core preform to form an outside vapor-deposited layer that forms a cladding of the optical fiber in a state where the core preform is put into the chamber; and heating and sintering the porous preform. When obtaining the porous preform, the outside vapor-deposited layer is formed by repeatedly performing the deposition of the glass particles multiple times through supply of source material gas. In a first deposition among the multiple times of deposition of the glass particles, a flow rate of the source material gas is less than or equal to 50% of a stable value.Type: ApplicationFiled: April 22, 2019Publication date: August 15, 2019Applicant: Fujikura Ltd.Inventor: Katsubumi Nagasu
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Publication number: 20190113678Abstract: An optical fiber includes: a core; a cladding layer that is lower in refractive index than the core; and a depressed layer that lies between the core and the cladding layer and that is lower in refractive index than the cladding layer, wherein: the optical fiber has an effective core area Aeff that is equal to or greater than 100 ?m2 and equal to or less than 129 ?m2, the core has a radius r1 that is equal to or greater than 5.2 ?m and equal to or less than 7.4 ?m, the core has a refractive index volume Vcore that is equal to or greater than 8.5% ?m2 and equal to or less than 16.5% ?m2, the depressed layer has a refractive index volume Vdep that is equal to or greater than ?40% ?m2 and less than 0% ?m2.Type: ApplicationFiled: March 29, 2017Publication date: April 18, 2019Applicant: FUJIKURA LTD.Inventors: Katsubumi Nagasu, Ryo Maruyama
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Publication number: 20170285259Abstract: An optical fiber preform includes: a core formed of silica glass which does not contain Ge, wherein the core has at least one of characteristics in spectrometry of (1) an absorption peak is present at a wavelength of 240 nm to 255 nm, and (2) a wavelength at which an ultraviolet transmittance is 50% or lower is longer than 170 nm.Type: ApplicationFiled: June 10, 2016Publication date: October 5, 2017Applicant: Fujikura Ltd.Inventor: Katsubumi Nagasu
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Patent number: 7782049Abstract: A magnetic device comprises a magnetic element, a first magnetic field application device, and a second magnetic field application device. The first and second magnetic field applying means are disposed on mutually opposite sides of the magnetic element. The magnetic element is, for example, an element in which a soft magnetic film is formed in a meandering shape on a nonmagnetic substrate. The first and second magnetic field application device create a magnetic field in one direction from the first magnetic field application device toward the second magnetic field application device. The bias magnetic field in one direction is thereby applied to the entire soft magnetic film in the magnetic element disposed between the first and second magnetic field application device.Type: GrantFiled: November 7, 2008Date of Patent: August 24, 2010Assignee: Fujikura Ltd.Inventors: Kazuhisa Itoi, Katsubumi Nagasu, Takuya Aizawa, Osamu Nakao, Shigekazu Kawai
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Patent number: 7772841Abstract: A magnetic device comprises a magnetic element, a first magnetic field applying means, and a second magnetic field applying means. The first and second magnetic field applying means are disposed on mutually opposite sides of the magnetic element. The magnetic element is, for example, an element in which a soft magnetic film is formed in a meandering shape on a nonmagnetic substrate. The first and second magnetic field applying means create a magnetic field in one direction from the first magnetic field applying means toward the second magnetic field applying means. The bias magnetic field in one direction is thereby applied to the entire soft magnetic film in the magnetic element disposed between the first and second magnetic field applying means.Type: GrantFiled: January 13, 2010Date of Patent: August 10, 2010Assignee: Fujikura Ltd.Inventors: Kazuhisa Itoi, Katsubumi Nagasu, Takuya Aizawa, Osamu Nakao, Shigekazu Kawai
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Publication number: 20100109663Abstract: A magnetic device comprises a magnetic element, a first magnetic field applying means, and a second magnetic field applying means. The first and second magnetic field applying means are disposed on mutually opposite sides of the magnetic element. The magnetic element is, for example, an element in which a soft magnetic film is formed in a meandering shape on a nonmagnetic substrate. The first and second magnetic field applying means create a magnetic field in one direction from the first magnetic field applying means toward the second magnetic field applying means. The bias magnetic field in one direction is thereby applied to the entire soft magnetic film in the magnetic element disposed between the first and second magnetic field applying means.Type: ApplicationFiled: January 13, 2010Publication date: May 6, 2010Applicant: Fujikura Ltd.Inventors: Kazuhisa ITOI, Katsubumi Nagasu, Takuya Aizawa, Osamu Nakao, Shigekazu Kawai
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Publication number: 20100090692Abstract: A magnetic sensor module which includes: a semiconductor substrate including an integrated circuit for switching operation; a magneto-resistive element which is disposed on a first surface of the semiconductor substrate and has a magneto-sensitive direction in a direction along the first surface; and a bias magnetic field applying member provided on the semiconductor substrate and disposed on a surface which is parallel to the first surface, wherein: the bias magnetic field applying member is magnetized in a direction along the surface on which the bias magnetic field applying member is disposed; and when no external magnetic field is applied, the bias magnetic field applying member applies a bias magnetic field in the direction along the first surface on which the magneto-resistive element is provided.Type: ApplicationFiled: February 8, 2008Publication date: April 15, 2010Applicant: FUJIKURA LTD.Inventors: Kazuhisa Itoi, Katsubumi Nagasu, Takuya Aizawa, Osamu Nakao
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Publication number: 20090066326Abstract: A magnetic device comprises a magnetic element, a first magnetic field applying means, and a second magnetic field applying means. The first and second magnetic field applying means are disposed on mutually opposite sides of the magnetic element. The magnetic element is, for example, an element in which a soft magnetic film is formed in a meandering shape on a nonmagnetic substrate. The first and second magnetic field applying means create a magnetic field in one direction from the first magnetic field applying means toward the second magnetic field applying means. The bias magnetic field in one direction is thereby applied to the entire soft magnetic film in the magnetic element disposed between the first and second magnetic field applying means.Type: ApplicationFiled: November 7, 2008Publication date: March 12, 2009Applicant: Fujikura Ltd.Inventors: Kazuhisa ITOI, Katsubumi Nagasu, Takuya Aizawa, Osamu Nakao, Shigekazu Kawai
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Publication number: 20050155390Abstract: An apparatus for manufacturing a porous glass preform for an optical fiber includes a glass synthesizing burner, a gas source for supplying a glass forming gas to the glass synthesizing burner, and a piping for connecting the gas source to the glass synthesizing burner, in which the piping includes at least one layer made of flexible synthetic resin, wherein a ratio of a moisture permeability coefficient P (g·cm/cm2·s·cmHg) of the piping to a thickness L of the piping (cm) (P/L) is less than 1.0×10?10 g/cm2·s·cmHg.Type: ApplicationFiled: January 12, 2005Publication date: July 21, 2005Inventors: Katsubumi Nagasu, Naritoshi Yamada