Patents by Inventor Keishi Ohashi

Keishi Ohashi 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: 20060269182
    Abstract: Laser light emitted from a vertically confined surface emitting laser (VCSEL) is incident on a side surface near an end region of an optical waveguide. The end region of the optical waveguide is processed by polishing to taper at an angle of 45 degrees, and an optical modulator is formed on the polished surface. The optical modulator is a Fabry-Perot modulator using a linear electro-optical effect. The modulator has a thick transparent electro-optical layer which is deposited by using an aerosol deposition method.
    Type: Application
    Filed: August 1, 2006
    Publication date: November 30, 2006
    Applicant: NEC Corporation
    Inventors: Masafumi Nakada, Keishi Ohashi
  • Publication number: 20060232894
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Application
    Filed: March 16, 2006
    Publication date: October 19, 2006
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Patent number: 7120326
    Abstract: An optical element is formed from a molded body which is formed using an impact consolidation phenomenon in which mechanical impact is applied to ultra fine fragile particles which are supplied onto a substrate so that the ultra fine fragile particles are pulverized and bonded to each other. In the optical element, d6/?4<4×10?5 nm2 holds, in which d (nm) represents the average radius of a part of the molded body, such as a pore (void) or a different phase, having a refractive index different from that of a primary component of the molded body, and in which ? (nm) represents the wavelength of light transmitting through the molded body.
    Type: Grant
    Filed: November 26, 2004
    Date of Patent: October 10, 2006
    Assignees: NEC Corporation, National Institute of Advanced Industrial Science and Technology
    Inventors: Masafumi Nakada, Keishi Ohashi, Jun Akedo
  • Patent number: 7042319
    Abstract: The present invention provided a thin-film electromagnet including a magnetic yoke and a thin-film coil, characterized in that the magnetic yoke includes a first magnetic yoke and a second magnetic yoke making contact with the first magnetic yoke, the first magnetic yoke is located at a center of a winding of the thin-film coil, and the second magnetic yoke is arranged above or below the thin-film coil such that the second magnetic yoke faces the thin-film coil, and overlaps at least a part of the thin-film coil.
    Type: Grant
    Filed: August 15, 2002
    Date of Patent: May 9, 2006
    Assignee: Denso Corporation
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Keishi Ohashi
  • Patent number: 6999287
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: February 14, 2006
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Publication number: 20060007606
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Application
    Filed: September 16, 2005
    Publication date: January 12, 2006
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Publication number: 20050219772
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Application
    Filed: May 31, 2005
    Publication date: October 6, 2005
    Applicant: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Publication number: 20050220386
    Abstract: Laser light emitted from a vertically confined surface emitting laser (VCSEL) is incident on a side surface near an end region of an optical waveguide. The end region of the optical waveguide is processed by polishing to taper at an angle of 45 degrees, and an optical modulator is formed on the polished surface. The optical modulator is a Fabry-Perot modulator using a linear electro-optical effect. The modulator has a thick transparent electro-optical layer which is deposited by using an aerosol deposition method.
    Type: Application
    Filed: March 28, 2005
    Publication date: October 6, 2005
    Applicant: NEC CORPORATION
    Inventors: Masafumi Nakada, Keishi Ohashi
  • Patent number: 6950290
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: September 27, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Publication number: 20050185339
    Abstract: A recording head is a magnetic head in which ends on one side of opposed first and second magnetic cores form a recording gap, said other ends form a magnetic joint, coils insulated by an insulating material are provided between said first and second magnetic cores, magnetic fluxes of said first and second magnetic cores excited by said coils leak from said recording gap so that recording onto a recording medium is carried out. In said recording head, a distance from said end of said recording gap close to said magnetic medium to a contact point of said magnetic joint (hereinafter, yoke length) is not more than 20 ?m. A magnetic recording/reproduction apparatus has this head.
    Type: Application
    Filed: August 5, 2004
    Publication date: August 25, 2005
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Yoshihiro Nonaka, Tsutomu Ishi, Mikiko Saito, Keishi Ohashi
  • Patent number: 6934132
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed inmediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: August 23, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Publication number: 20050147343
    Abstract: An optical element is formed from a molded body which is formed using an impact consolidation phenomenon in which a mechanical impact is applied to ultra fine fragile particles which are supplied onto a substrate so that the ultra fine fragile particles are pulverized and bonded to each other In the optical element, d6/?4<4×10?5 nm2 holds, in which d (nm) represents the average radius of a part of the molded body, such as a pore (void) or a different phase, having a refractive index different from that of a primary component of the molded body, and in which ? (nm) represents the wavelength of light transmitting through the molded body.
    Type: Application
    Filed: November 26, 2004
    Publication date: July 7, 2005
    Inventors: Masafumi Nakada, Keishi Ohashi, Jun Akedo
  • Patent number: 6903908
    Abstract: A magnetoresistive effect sensor uses a shielded-type magnetoresistive effect element using a magnetoresistive effect film formed by a basic configuration of a combination of a free layer, a barrier layer formed on the free layer, and a fixed layer formed on the barrier layer, wherein a sensing current flows substantially perpendicular to the magnetoresistive effect film, and wherein an amorphous material or a microcrystalline material is used in a lower shield.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: June 7, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjo, Junichi Fujikata, Kunihiko Ishihara, Shigeru Mori
  • Publication number: 20050047010
    Abstract: The present invention provided a thin-film electromagnet including a magnetic yoke and a thin-film coil, characterized in that the magnetic yoke is comprised of a first magnetic yoke and a second magnetic yoke making contact with the first magnetic yoke, the first magnetic yoke is located at a center of a winding of which the thin-film coil is comprised, and the second magnetic yoke is arranged above or below the thin-film coil such that the second magnetic yoke faces the thin-film coil, and overlaps at least a part of the thin-film coil.
    Type: Application
    Filed: August 15, 2002
    Publication date: March 3, 2005
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Keishi Ohashi
  • Patent number: 6798626
    Abstract: A magnetoresistive effect element which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the element and a magnetic recording apparatus utilizing the element. This magnetoresistive effect element utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: September 28, 2004
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjou, Shinsaku Saitoh
  • Patent number: 6795271
    Abstract: A recording head is a magnetic head in which ends on one side of opposed first and second magnetic cores form a recording gap, said other ends form a magnetic joint, coils insulated by an insulating material are provided between said first and second magnetic cores, magnetic fluxes of said first and second magnetic cores excited by said coils leak from said recording gap so that recording onto a recording medium is carried out. In said recording head, a distance from said end of said recording gap close to said magnetic medium to a contact point of said magnetic joint (hereinafter, yoke length) is not more than 20 &mgr;m. A magnetic recording/reproduction apparatus has this head.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: September 21, 2004
    Assignee: NEC Corporation
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Yoshihiro Nonaka, Tsutomu Ishi, Mikiko Saito, Keishi Ohashi
  • Publication number: 20040174641
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Application
    Filed: March 18, 2004
    Publication date: September 9, 2004
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokasu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Patent number: 6747853
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Grant
    Filed: May 21, 2003
    Date of Patent: June 8, 2004
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Patent number: 6718621
    Abstract: In a production process of an MR head using the tunnel junction film basically consisting of a free layer, a barrier layer, and a pinned layer, the resistance between the free layer and the pined layer reduced beforehand and increased afterward up to a resistance value necessary when actually used. While the resistance between the free layer and the pinned layer is low, current can easily flow, suppressing charge up, thus preventing insulation destruction of the barrier layer. This significantly increases a production yield of a recording/reproduction head using a ferromagnetic tunnel junction element.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: April 13, 2004
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjo, Shinsaku Saitoh
  • Patent number: 6714374
    Abstract: A magnetoresistive sensor includes a magnetoresistive element and equipment which generates a magnetic field in the magnetoresistive element thereby inducing a biasing magnetic field in the element, where the magnetoresistive element comprises a high electron mobility semiconductor and electrodes which are connected to the semiconductor. If it is an insulator, the equipment, which generates the biasing magnetic field and supplies it to the magnetoresistive element, may contact directly to the magnetoresistive element. If it is a conductor, an insulating separation layer must be set between the equipment and the element. A magnetoresistive element is representatively Corbino disk type or a bar type magnetoresistive element. Another candidate of the magnetoresistive element is an element consisting of a high electron mobility semiconductor, a pair of electrodes which make a current path in the high electron mobility semiconductor, and another pair of electrodes to detect the induced voltage by the current.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: March 30, 2004
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Stuart Solin, Tao Zhou