Patents by Inventor Kohei Kobayashi

Kohei Kobayashi 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).

  • Publication number: 20040013395
    Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.
    Type: Application
    Filed: August 14, 2002
    Publication date: January 22, 2004
    Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi, Kenji Tamano, Takashi Fujii
  • Patent number: 6650821
    Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.
    Type: Grant
    Filed: January 4, 2000
    Date of Patent: November 18, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi, Kenji Tamano, Takashi Fujii
  • Patent number: 6628872
    Abstract: There is disclosed a dispersion compensator for compensating for a chromatic dispersion and dispersion slope of an optical fiber transmission line, the dispersion compensator comprising a plurality of dispersion-compensating optical fibers connected to each other, the dispersion-compensating optical fibers each having a dispersion slope compensation ratio of at least 60% with respect to the optical fiber transmission line at a predetermined wavelength, one of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio of at least 80%, another of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio within the range of 60% to 100%.
    Type: Grant
    Filed: March 13, 2001
    Date of Patent: September 30, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Mitsuomi Hada, Kohei Kobayashi, Kenji Tamano, Keiichiro Fukuda, Masashi Onishi
  • Patent number: 6614976
    Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, disposed at the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is at least 0.30% but not greater than 0.50%, and the relative refractive index difference of the inner cladding with respect to the outer cladding is at least −0.50% but not greater than −0.02%. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective cross-sectional area Aeff of at least 70 &mgr;m2 at the wavelength of 1.55 &mgr;m.
    Type: Grant
    Filed: January 7, 2002
    Date of Patent: September 2, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takatoshi Kato, Kazuhiro Okamoto, Mitsuomi Hada, Shinjiro Hagihara, Morio Watanabe, Kohei Kobayashi
  • Publication number: 20030142938
    Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44, respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.
    Type: Application
    Filed: February 10, 2003
    Publication date: July 31, 2003
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi
  • Patent number: 6597846
    Abstract: An optical fiber (1) which does not readily suffer influences of side pressures and can realize superior transmission characteristics, having a glass part (2, 3) having a core (2) and at least one cladding (3) and at least one covering layer (4a, 4b) formed around the glass part (2, 3), characterized in that the Young's modulus at 23° C. of the covering layer (4) without the glass part (2, 3) is not greater than 400 MPa. The Young's modulus measurement of the covering layer (4) is obtained by removing the glass part (2, 3) from the optical fiber (1) and putting the covering layer (4) to a tensile test.
    Type: Grant
    Filed: May 8, 2001
    Date of Patent: July 22, 2003
    Assignee: Sumitomo Electric Industries Co., Ltd.
    Inventors: Takashi Fujii, Toshifumi Hosoya, Kenji Tamano, Keiichiro Fukuda, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi
  • Patent number: 6546760
    Abstract: There is provided an optical fiber drawing furnace capable of drawing an optical fiber having small non circularity, which drawing furnace includes a muffle tube, in which an optical fiber preform is supplied, a heater surrounding the muffle tube, a plurality of electrode connecting portion extending from the heater, a plurality of electrodes connected to electrode connecting portions, and in conjunction therewith to an electric power source, and unifying means for unifying the temperature distribution along the circumferential direction.
    Type: Grant
    Filed: July 3, 1996
    Date of Patent: April 15, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Ichiro Tsuchiya, Kohei Kobayashi, Hiroaki Ohta, Kazuya Kuwahara, Katsuyuki Tsuneishi, Hideo Miyaki, Yasuo Matsuda
  • Patent number: 6546180
    Abstract: After a wide-band DCF is wound around a bobbin to form an optical fiber coil 32, the latter is removed from the bobbin and placed into a bundle state (the state where the increase in transmission loss in the wavelength band of 1.55 &mgr;m caused by distortions in winding is reduced by 0.1 dB/km or more) released from distortions in winding. A resin 42 is used as a coil-tidying member so as to secure the optical fiber coil 32 to a storage case 40 at four positions. Both ends of the optical fiber coil 32 are connected to pigtail fibers at fusion-splicing parts 44; respectively. Even when the storage case 40 is closed with a lid after the optical fiber coil 32 is secured to the storage case 40 with the resin 42, there remain interstices within the bundle of the optical fiber coil 32 and a space between the optical fiber coil 32 and the storage case 40. As a result, even when the optical fiber coil 32 in a bundle state is accommodated in the storage case 40, transmission loss and the like would not increase.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: April 8, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yasushi Koyano, Eisuke Sasaoka, Shigeru Tanaka, Kohei Kobayashi, Masashi Onishi
  • Patent number: 6471892
    Abstract: In a method of making a ribbon type coated optical fiber 3 comprising the step of inserting a plurality of optical fibers 1 flatly arranged parallel to each other through a die orifice 11a so as to collectively coat the optical fibers with a coating resin 2, the ratio W/H of a clearance W in the width direction between the inner surface of the die orifice 11a and the outer surface of the optical fibers 1 to a clearance H in the thickness direction therebetween is set within the range of 1.0 to 2.5.
    Type: Grant
    Filed: May 18, 2000
    Date of Patent: October 29, 2002
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Ken Takahashi, Shigenori Takaki, Ryoei Oka, Tomoyuki Hattori, Toshihisa Sato, Kohei Kobayashi, Kaoru Okuno
  • Publication number: 20020106172
    Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, disposed at the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is at least 0.30% but not greater than 0.50%, and the relative refractive index difference of the inner cladding with respect to the outer cladding is at least −0.50% but not greater than −0.02%. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective cross-sectional area Aeff of at least 70 &mgr;m2 at the wavelength of 1.55 &mgr;m.
    Type: Application
    Filed: January 7, 2002
    Publication date: August 8, 2002
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takatoshi Kato, Kazuhiro Okamoto, Mitsuomi Hada, Shinjiro Hagihara, Morio Watanabe, Kohei Kobayashi
  • Patent number: 6345916
    Abstract: The present invention provides a fiber optic connector comprising a fiber pressing member and a substrate having a part A with multiple fiber arranging grooves in which bare portion of optical fibers are fixed, and a part B in which coated portion of optical fibers are fixed, and its manufacturing method. The connector enables to prevent an increase in transmission loss or breakage of the optical fibers by reducing the localized stress on the fibers from the rear end of the fiber pressing member and the rear end edge of the fiber arranging grooves.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: February 12, 2002
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Dai Yui, Kei Sunaga, Teruo Ikechi, Hidetoshi Ishida, Manabu Shiozaki, Takashi Sasaki, Kohei Kobayashi
  • Patent number: 6337942
    Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, disposed at the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is at least 0.30% but not greater than 0.50%, and the relative refractive index difference of the inner cladding with respect to the outer cladding is at least −0.50% but not greater than −0.02%. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective cross-sectional area Aeff of at least 70 &mgr;m2 at the wavelength of 1.55 &mgr;m.
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: January 8, 2002
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takatoshi Kato, Kazuhiro Okamoto, Mitsuomi Hada, Shinjiro Hagihara, Morio Watanabe, Kohei Kobayashi
  • Patent number: 6333071
    Abstract: An apparatus for producing optical fiber ribbons which has a optical fiber gathering device, one or more coating applicators and a turn roller arranged in a straight line, with one or more alignment guide in plate form being provided on a travelling line of optical fibers or optical fiber ribbons upstream of the coating applicator. The alignment guide is chamfered to arch form on the side that contacts the optical fibers or the optical fiber ribbons. The alignment guide suppresses the optical fibers or the optical fiber ribbons from vibrating in a direction perpendicular to the direction of the arrangement of the optical fibers or the optical fiber ribbons.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: December 25, 2001
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kohei Kobayashi, Ichiro Tsuchiya, Tomoyuki Hattori
  • Publication number: 20010051031
    Abstract: There is disclosed a dispersion compensator for compensating for a chromatic dispersion and dispersion slope of an optical fiber transmission line, the dispersion compensator comprising a plurality of dispersion-compensating optical fibers connected to each other, the dispersion-compensating optical fibers each having a dispersion slope compensation ratio of at least 60% with respect to the optical fiber transmission line at a predetermined wavelength, one of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio of at least 80%, another of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio within the range of 60% to 100%.
    Type: Application
    Filed: March 13, 2001
    Publication date: December 13, 2001
    Inventors: Mitsuomi Hada, Kohei Kobayashi, Kenji Tamano, Keiichiro Fukuda, Masashi Onishi
  • Patent number: 6309567
    Abstract: A collectively coating die device (2) is provided for applying coating resin in a lump to coated optical fibers (1) arranged in parallel on one and the same plane so as to form a plurality of optical fiber ribbons (16) at the same time. The collectively coating die device (2) has a nipple portion (9) and a die portion (10), a resin accumulation space (8) formed between the nipple portion (9) and the die portion (10). The nipple portion (9) has two parallel planes and having a plurality of optical fiber passageways (13) shaped like ellipses in section and provided in the direction perpendicular to the planes. The die portion (10) has two parallel planes and has a plurality of optical fiber passageways (14) shaped like ellipses in section and is provided in the direction perpendicular to the planes. Each of the optical fiber passageways (13) of the nipple portion (9) has a tapered portion.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: October 30, 2001
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kaoru Okuno, Ichiro Tsuchiya, Kohei Kobayashi, Tomoyuki Hattori, Ken Takahashi
  • Patent number: 6028976
    Abstract: In a split type ribbon optical fiber core cable capable of being split into cables, there are a plurality of ribbon optical fiber core cable units, each of which are constituted by a plurality of colored optical fiber core cables arranged in a row; a coating resin of an ultraviolet curable resin wholly coats the plurality of colored optical fiber core cables; and a bonding resin of an ultraviolet curable resin bonds the ribbon optical fiber core cable units arranged in a row. In this cable, an adhesion strength between the coating resin and the bonding resin is in the range of 1 to 100 g/cm. Further, the bonding resin after curing has a Young's modulus of from 5 to 100 kg/mm.sup.2. The bonding resin after curing has an elongation coefficient of from 5 to 80%.
    Type: Grant
    Filed: November 18, 1997
    Date of Patent: February 22, 2000
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Toshihisa Sato, Tomoyuki Hattori, Kohei Kobayashi, Kaoru Okuno, Ken Takahashi, Ryoei Oka
  • Patent number: 6004675
    Abstract: A coated glass fiber for light transmission consisting of a glass fiber for light transmission and at least one coating layer made of a UV-curing resin, wherein an outermost layer of the coating layer is made of a UV-curing resin having a Young's modulus of at least 100 kg/mm.sup.2 and a change of a cure shrinkage degree of 1% or less after a Young's modulus reaches one tenth of an end Young's modulus, which has good lateral pressure characteristics and low transmission loss.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: December 21, 1999
    Assignees: Sumitomo Electric Industries, Ltd., Nippon Telegraph & Telephone Corp.
    Inventors: Nobuhiro Akasaka, Tatsuya Kakuta, Kohei Kobayashi, Yasuo Matsuda, Shigeru Tomita
  • Patent number: 5976611
    Abstract: The present invention relates to an optical fiber coating method and an apparatus therefor which can form high quality coating layer on an optical fiber (12) by preventing non-concentricity of a coating resin (14) applied on the optical fiber (12) and admixing of bubble.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: November 2, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kaoru Okuno, Akira Inoue, Kazumasa Oishi, Kohei Kobayashi, Ichiro Tsuchiya
  • Patent number: 5945173
    Abstract: An optical fiber ribbon is manufactured under a condition where, assuming that the optical fiber ribbon has a thickness of 2d (mm), a guide roller has a diameter of 2R (mm), and a period of time till the optical fiber ribbon comes into contact with the guide roller after leaving an ultraviolet irradiation apparatus is t (ms), a relationship of d/?(R+d).times.t!<0.2 is satisfied. Accordingly, no damages are imparted to the optical fiber ribbon, and no micro-bendings occur in its coated optical fibers, whereby the transmission characteristic can be prevented from deteriorating.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: August 31, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tomoyuki Hattori, Toshihisa Sato, Kohei Kobayashi, Kaoru Okuno, Ken Takahashi, Ryoei Oka
  • Patent number: 5904883
    Abstract: In a method for producing an optical fiber ribbon, a plurality of coated optical fibers is fed out so that the plurality of coated optical fibers are arranged in a plane in a concentrator. A ribbon matrix composed of ultraviolet-curing resin is applied onto the plurality of coated optical fibers in a coater. Ultraviolet rays is radiated to cure the ribbon matrix. The plurality of coated optical fibers are arranged at intervals in a plane in the concentrator.
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: May 18, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tomoyuki Hattori, Toshihisa Sato, Kohei Kobayashi, Kaoru Okuno, Ken Takahashi, Ryoei Oka, Masayuki Okubo