Patents by Inventor Seiji Kojima
Seiji 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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Patent number: 7684449Abstract: A cladding is provided at an outer periphery of a solid-core doped with rare earth ions, and a metal layer is formed to be adjacent to the cladding to provide an optical fiber for a fiber laser device. The metal layer having an inner metal layer and an outer metal layer is disposed along an entire length of the optical fiber for a fiber laser device. An exciting light is incident to the optical fiber for a fiber laser device, and the exciting light is reflection-excited to emit a high power laser oscillation light. A monitoring current is constantly flown into the metal layer. When the disconnection of the optical fiber for a fiber laser device is detected based on the monitoring current, the energization of the optical fiber for a fiber laser device is stopped.Type: GrantFiled: December 3, 2007Date of Patent: March 23, 2010Assignee: Hitachi Cable, Ltd.Inventors: Kazumasa Ohsono, Akihito Hongo, Seiji Kojima, Bing Yao
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Publication number: 20100047100Abstract: A tube pump rotor including a rotor element, a plurality of first swing portions supported pivotally at their base end portions by the rotor element, second arm-shaped swing portions supported pivotally at their base end portions individually by the first swing portions, rollers supported rotatably by the individual free ends of the second swing portions, and buffer members made to confront the side faces of the second swing portions so that the rollers may be individually directed radially outward of the rotor.Type: ApplicationFiled: February 18, 2008Publication date: February 25, 2010Applicant: JMS CO., LTD.Inventors: Seiji Kojima, Kou Sekiya, Junya Fujii, Shogo Kamito
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Publication number: 20100008676Abstract: A communication light detecting device interconnecting light transmission paths and collocated therebetween, comprises: an optical coupling body including a core portion for photo coupling with the light transmission paths, and a light extracting portion for extracting a part of the communication light as a leakage light; and a light detecting portion having a light receiving member for receiving the leakage light. The light extracting portion is preferable to possess a lower refractive index than that of the core portion. Besides, the light extracting portion is preferable to include a light detecting use groove with a groove width of 50 ?m or more and 140 ?m or less formed by cutting and separating the core portion. Besides, the light extracting portion is preferable to be the optical coupling body in which outer diameter of the core portion is different from the outer diameter of a core of the light transmission path.Type: ApplicationFiled: May 14, 2009Publication date: January 14, 2010Inventors: Seiji Kojima, Kanako Suzuki, Yoshihiro Nakatani, Toshihiko Ishikawa, Takao Nishikawa, Kojiro Ito, Tetsuya Sueoka
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Patent number: 7589312Abstract: A physical quantity measuring system includes an optical fiber in which plural fiber Bragg gratings having different reflection wavelength changing bands are formed along the optical fiber in a longitudinal direction, a light source which outputs a broadband light into the optical fiber, an arrayed waveguide grating and an operating portion. The arrayed waveguide grating divides a light reflected by the fiber Bragg grating and outputted from the optical fiber into plural divisional wavelength bands. The arrayed waveguide grating outputs the divided lights to output channels. The operating portion detects a change of a reflected center wavelength of each fiber Bragg grating by a change of an output of each light-receiving element, operates a physical quantity and a position thereof given to the optical fiber, and is capable of detecting light from adjacent output channels.Type: GrantFiled: December 3, 2007Date of Patent: September 15, 2009Assignee: Hitachi Cable, Ltd.Inventor: Seiji Kojima
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Publication number: 20090129411Abstract: An optical fiber laser, according to the present invention, has an optical fiber including a core to which a rare earth element is added and a clad disposed around the core, and also has an excitation light source for emitting excitation light incident on a side of the optical fiber. The optical fiber has a corrugated shape on the outer circumference of the clad along the longitudinal direction thereof; and the optical fiber is wound in a spiral form and is bundled in such a way that adjacent sides of the clad are brought into contact with one another.Type: ApplicationFiled: November 20, 2008Publication date: May 21, 2009Inventors: Seiji Kojima, Bing Yao, Kazumasa Ohsono, Akihito Hongo, Akio Sato, Kohei Yanaka, Kazuo Hasegawa, Daisuke Inoue, Hiroshi Ito, Tadashi Ichikawa, Kazuya Saito
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Publication number: 20090080472Abstract: The optical fiber 1 for an optical fiber laser is provided with a rare earth element doped core 2 doped with a rare earth element, and a cladding 3 formed at an outer periphery of the rare earth element doped core 2. In the optical fiber 1 for an optical fiber laser, the rare earth element doped core 2 is divided into a plurality of core regions 2a, 2b, . . . , 2n?1, 2n along a longitudinal direction of the optical fiber 1 and dopant concentrations of the rare earth element in respective core regions 2a, 2b, . . . , 2n?1, 2n are different from each other, in order to flatten a temperature distribution of the optical fiber 1 along the longitudinal direction.Type: ApplicationFiled: July 25, 2008Publication date: March 26, 2009Applicant: Hitachi Cable, Ltd.Inventors: Bing Yao, Seiji Kojima, Kazumasa Ohsono, Akihito Hongo
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Publication number: 20090052476Abstract: The optical fiber 1 for an optical fiber laser is provided with a rare earth element doped core 2 doped with a rare earth element, a cladding 3 formed at an outer periphery of the rare earth element doped core 2, a core vicinity part 3? of the cladding 3 provided in vicinity of the rare earth element doped core 2 being doped with a refractive index increasing agent which reduces a relative refractive index difference between the core vicinity part 3? and the rare earth element doped core 2 to be 0.1% or less.Type: ApplicationFiled: August 5, 2008Publication date: February 26, 2009Applicant: HITACHI CABLE, LTD.Inventors: Bing Yao, Seiji Kojima, Kazumasa Ohsono, Akihito Hongo
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Publication number: 20090052840Abstract: A plurality of light emitting elements 11 are arranged in parallel with a constant pitch to provide a semiconductor laser bar 10. An optical waveguide 20 has a core part 21 for guiding a light emitted from each of the light emitting elements 11 and a cladding part 22 formed around the core part 21. An optical fiber 30 has a core 31 and a cladding 32 formed around the core 31 for confining the light to the core 31. The optical waveguide is bonded to a side surface of the optical fiber 30, and the light emitted from the semiconductor laser bar 10 is inputted to a side surface of the core 31 of the optical fiber 30 via the core part 21 of the optical waveguide 20.Type: ApplicationFiled: August 20, 2008Publication date: February 26, 2009Applicants: HITACHI CABLE, LTD., TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota School FoundationInventors: Seiji Kojima, Akihito Hongo, Kazumasa Ohsono, Bing Yao, Akio Satou, Kohei Yanaka, Kazuo Hasegawa, Daisuke Inoue, Hiroshi Ito, Tadashi Ichikawa, Kazuya Saito
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Patent number: 7470888Abstract: A damage detection system including: a optical fiber sensor including a core portion to have a grating portion formed therein, the grating portion having gratings reflecting light, wherein a wavelength band of the reflected light changes when a distance between adjacent gratings changes; a light source to input broadband light into the core portion; two optical filters connected to an output end of the sensor; and an apparatus to perform arithmetic processing on output values of the optical filters, wherein each passband of the optical filters overlaps with the vibration range of the wavelength band, in which a center wavelength of one of the passbands is fixed to an upper area of a vibration center of a center wavelength of the reflected light and that of the other of the passbands is fixed to a lower area thereof.Type: GrantFiled: February 21, 2007Date of Patent: December 30, 2008Assignees: Fuji Jukogyo Kabushiki Kaisha, Hitachi Cable, Ltd., The University Of TokyoInventors: Toshimichi Ogisu, Seiji Kojima, Nobuo Takeda
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Publication number: 20080309945Abstract: A physical quantity measuring system according to the present invention comprises: an optical fiber having fiber Bragg gratings; a light source connected to the optical fiber; an arrayed waveguide grating connected between the light source and the optical fiber via an optical branching filter, and having output channels of which central wavelengths of at least three output channels are included in a one-tenth loss band of a reflected light by the fiber Bragg grating; light receiving devices for receiving light output from the output channels on a one-to-one basis; and a central reflected wavelength change detecting unit connected to the light receiving devices for estimating a change in a central reflected wavelength based on a physical quantity, by calculating first and second group signals from light receiving signals corresponding to the at least three output channels, and by calculating a differential signal between the first and the second group signals.Type: ApplicationFiled: March 18, 2008Publication date: December 18, 2008Inventors: Seiji KOJIMA, Shinji KOMATSUZALI
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Patent number: 7459189Abstract: A liquid crystal/polymer composite is sandwiched between a pair of substrates with electrodes, the polymer forms a plurality of column resins, column resins of which the major axis directions substantially agree with the normal direction of the substrate plane and column resins which are aligned on the tilt coexist, the content of the polymer is at least 10 wt %, the alignment of the liquid crystal substantially agrees with the normal direction and the liquid crystal is in a light transmitting state under application of no voltage, and the alignment of the liquid crystal changes and the liquid crystal is in a light scattering state under application of a voltage.Type: GrantFiled: December 17, 2004Date of Patent: December 2, 2008Assignee: Asahi Glass Company, LimitedInventors: Shinya Tahara, Seiji Kojima, Shunichi Suwa, Masao Ozeki, Satoshi Niiyama
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Publication number: 20080267229Abstract: An optical fiber includes a rare-earth element-added core for serving as a gain medium, and a cladding formed on a periphery of the core. Pump light propagated through the cladding is coupled into the core. The cladding is in an undulation shape in the longitudinal direction of the cladding. The undulation shape of the cladding is formed according to a grating period at which the pump light is totally reflected and propagated in the cladding. The core includes an undulation shape in a longitudinal direction of the core. The cladding includes an undulating inner cladding, and an outer cladding provided on a periphery of the inner cladding. The core and/or the cladding is circular or abnormally circular in its transverse cross section.Type: ApplicationFiled: April 25, 2008Publication date: October 30, 2008Applicants: HITACHI CABLE, LTD., TOYOTA SCHOOL FOUNDATIONInventors: Seiji Kojima, Akihito Hongo, Kazumasa Ohsono, Bing Yao, Kazuya Saito
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Publication number: 20080192778Abstract: A cladding is provided at an outer periphery of a solid-core doped with rare earth ions, and a metal layer is formed to be adjacent to the cladding to provide an optical fiber for a fiber laser device. The metal layer having an inner metal layer and an outer metal layer is disposed along an entire length of the optical fiber for a fiber laser device. An exciting light is incident to the optical fiber for a fiber laser device, and the exciting light is reflection-excited to emit a high power laser oscillation light. A monitoring current is constantly flown into the metal layer. When the disconnection of the optical fiber for a fiber laser device is detected based on the monitoring current, the energization of the optical fiber for a fiber laser device is stopped.Type: ApplicationFiled: December 3, 2007Publication date: August 14, 2008Applicant: HITACHI CABLE, LTD.Inventors: Kazumasa Ohsono, Akihito Hongo, Seiji Kojima, Bing Yao
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Patent number: 7405391Abstract: A modular sensor for damage detection with an optical fiber (FBG sensor) to detect a damage of a composite material, having a high level of visibility and manageability, and its manufacturing method is described. A structural composite material embedded with this modular sensor for damage detection is also described.Type: GrantFiled: December 14, 2005Date of Patent: July 29, 2008Assignee: Fuji Jukogyo Kabushiki KaishaInventors: Toshimichi Ogisu, Seiji Kojima
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Publication number: 20080156971Abstract: A modular sensor for damage detection with an optical fiber (FBG sensor) to detect a damage of a composite material, having a high level of visibility and manageability, and its manufacturing method is described. A structural composite material embedded with this modular sensor for damage detection is also described.Type: ApplicationFiled: December 14, 2005Publication date: July 3, 2008Inventors: Toshimichi Ogisu, Seiji Kojima
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Publication number: 20080142693Abstract: A physical quantity measuring system, includes an optical fiber in which plural fiber Bragg gratings having different reflection wavelength changing bands are formed along said optical fiber in a longitudinal direction, a light source which outputs a broadband light covering the reflection wavelength changing bands of all of the fiber Bragg gratings into the optical fiber, an arrayed waveguide grating which divides a light reflected by the fiber Bragg gratings and outputted from the optical fiber into plural divisional wavelength bands having a constant wavelength interval, and which outputs the divided lights to output channels, respectively, and an operating portion which detects a change of a reflected center wavelength of each fiber Bragg grating by a change of an output of each light-receiving element, and which operates a physical quantity and a position thereof given to the optical fiber, and which is capable of detecting light from adjacent output channels.Type: ApplicationFiled: December 3, 2007Publication date: June 19, 2008Inventor: Seiji Kojima
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Patent number: 7333696Abstract: A tape-shaped optical fiber cable has: a tape member formed of a fiber material and a cured resin formed around the fiber material; and an optical fiber embedded in the tape member. The optical fiber is covered by a covering material, the fiber material comprises a bidirectional fiber material. The optical fiber is embedded in the tape member such that one fiber array direction of the bidirectional fiber material is parallel to a longitudinal direction of the optical fiber and the other fiber array direction of the bidirectional fiber material is perpendicular to the longitudinal direction of the optical fiber.Type: GrantFiled: January 29, 2007Date of Patent: February 19, 2008Assignee: Hitachi Cable, Ltd.Inventor: Seiji Kojima
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Publication number: 20070219495Abstract: A control system for a liquid infusion apparatus comprises a plurality of liquid infusion devices, each having a common connector of liquid infusion device side for an electric power supply line and a communication line, a plurality of racks stacked one another, each for receiving each of the liquid infusion devices, a plurality of common connectors of rack side, each mounted on each of the racks a base unit, and a connector provided on the base unit so as to connect an electric power supply line and a communication line to the connectors of lack side. Each of the common connectors of rack side is connected to each of the common connectors of liquid infusion device side, when each of the liquid infusion devices is inserted into each of the respective racks.Type: ApplicationFiled: March 15, 2007Publication date: September 20, 2007Applicant: JAPAN SERVO CO., LTD.Inventors: Hiroshi Kato, Shunichi Kawamata, Seiji Kojima, Yoshihisa Kagawa, Koji Mizukami, Takahiro Matsumoto
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Publication number: 20070200057Abstract: A damage detection system including: a optical fiber sensor including a core portion to have a grating portion formed therein, the grating portion having gratings reflecting light, wherein a wavelength band of the reflected light changes when a distance between adjacent gratings changes; a light source to input broadband light into the core portion; two optical filters connected to an output end of the sensor; and an apparatus to perform arithmetic processing on output values of the optical filters, wherein each passband of the optical filters overlaps with the vibration range of the wavelength band, in which a center wavelength of one of the passbands is fixed to an upper area of a vibration center of a center wavelength of the reflected light and that of the other of the passbands is fixed to a lower area thereof.Type: ApplicationFiled: February 21, 2007Publication date: August 30, 2007Inventors: Toshimichi Ogisu, Seiji Kojima, Nobuo Takeda
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Publication number: 20070196059Abstract: A tape-shaped optical fiber cable has: a tape member formed of a fiber material and a cured resin formed around the fiber material; and an optical fiber embedded in the tape member. The optical fiber is covered by a covering material, the fiber material comprises a bidirectional fiber material. The optical fiber is embedded in the tape member such that one fiber array direction of the bidirectional fiber material is parallel to a longitudinal direction of the optical fiber and the other fiber array direction of the bidirectional fiber material is perpendicular to the longitudinal direction of the optical fiber.Type: ApplicationFiled: January 29, 2007Publication date: August 23, 2007Applicant: HITACHI CABLE, LTD.Inventor: Seiji Kojima