Patents by Inventor Toshifumi Ohkubo

Toshifumi Ohkubo 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).

  • Patent number: 7368146
    Abstract: A magneto-optical recording medium has a recording layer and a reflective layer on a substrate. The recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. A manufacturing method comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer. In the magneto-optical recording and playback device to record and play back data, the wavelength of light for recording data is different from that for reading data, which is preferable for a magneto-optical recording medium comprising a garnet ferrite layer.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: May 6, 2008
    Assignees: Nippon Telegraph and Telephone Corporation, The Centre National de la Recherche Scientifique
    Inventors: Akinori Furuya, Hiroshi Yoshikawa, Takaya Tanabe, Manabu Yamamoto, Toshifumi Ohkubo, Laurence Bouet, Philippe Tailhades, Corine Despax, Abel Rousset
  • Publication number: 20060286411
    Abstract: This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magneto-optical recording media. The magneto-optical recording medium of the present invention has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. The manufacturing method of the present invention comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer.
    Type: Application
    Filed: June 26, 2006
    Publication date: December 21, 2006
    Inventors: Akinori Furuya, Hiroshi Yoshikawa, Takaya Tanabe, Manabu Yamamoto, Toshifumi Ohkubo, Laurence Bouet, Philippe Tailhades, Corine Despax-Bonningue, Abel Rousset
  • Publication number: 20040197604
    Abstract: This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magnetic-optical recording media. The magneto-optical recording medium has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least on spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. The manufacturing method comprises the steps of heat treatment after the formation of the recording layer. In the magneto-optical recording and playback device to record and playback data, the wavelength of light for recording data is different from that for reading data, which is preferable for a magneto-optical recording medium comprising a garnet ferrite layer.
    Type: Application
    Filed: September 22, 2003
    Publication date: October 7, 2004
    Inventors: Akinori Furuya, Hiroshi Yoshikawa, Takaya Tanabe, Manabu Yamamoto, Toshifumi Ohkubo, Laurence Bouet, Philippe Tailhades, Corine Despax-Bonningue, Abel Rousset
  • Patent number: 6785201
    Abstract: It is an optical information recording and reading apparatus for recording and/or reading information at a high density by using a near-field light-generating device as a near-field optical head. The end surface of the core of a flexible optical waveguide is formed in an intermediate position in the optical waveguide and in a portion fixed to the near-field optical head. Light for recording and reading information is spread within the clad. The spread light flux is reflected toward the near-field optical head by a reflective surface formed on the side of one end of the optical waveguide. The reflected light flux is collected by light-collecting structures and then is made to enter an optical minute aperture formed in the near-field optical head. Near-field light is created near the minute aperture. Light scattered by the surface of the recording medium is received. Thus, information on the recording medium can be recorded and read.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: August 31, 2004
    Assignees: Seiko Instruments Inc.
    Inventors: Yoko Shinohara, Yasuyuki Mitsuoka, Manabu Oumi, Nobuyuki Kasama, Hidetaka Maeda, Kenji Kato, Susumu Ichihara, Takashi Niwa, Toshifumi Ohkubo, Terunao Hirota, Hiroshi Hosaka, Kiyoshi Itao
  • Patent number: 6759137
    Abstract: This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magneto-optical recording media. The magneto-optical recording medium of the present invention has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. The manufacturing method of the present invention comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer.
    Type: Grant
    Filed: April 21, 2000
    Date of Patent: July 6, 2004
    Assignee: Centre National de la Recherche Scientifique, Inc.
    Inventors: Akinori Furuya, Hiroshi Yoshikawa, Takaya Tanabe, Manabu Yamamoto, Toshifumi Ohkubo, Laurence Bouet, Philippe Tailhades, Corine Despax, Abel Rousset
  • Patent number: 6729541
    Abstract: An information reading apparatus can detect the coupling state of the input light to a waveguide of a laminated recording medium in a simple manner, so as to enable to focus the input light on a target recording layer to access the information recorded in the target recording layer quickly. The apparatus is compact and is economical to produce. The apparatus has a light source for injecting a light on an input edge of a lamination recording section, assembled into the recording medium containing a lamination of recording layers. Each recording layer has data represented by scattering centers which diffract an input light generated by a converging lens. An input light directing device directs the light source and the converging lens as a unit to focus the input light on a desired location. An image recording device records an informational image generated by guided waves produced within a laminated waveguide.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: May 4, 2004
    Assignee: Nippon Telegraph & Telephone Corporation
    Inventors: Yoshiaki Kurokawa, Toshifumi Ohkubo, Manabu Yamamoto, Takaya Tanabe, Shogo Yagi
  • Publication number: 20030002426
    Abstract: It is an optical information recording and reading apparatus for recording and/or reading information at a high density by using a near-field light-generating device as a near-field optical head. The end surface of the core of a flexible optical waveguide is formed in an intermediate position in the optical waveguide and in a portion fixed to the near-field optical head. Light for recording and reading information is spread within the clad. The spread light flux is reflected toward the near-field optical head by a reflective surface formed on the side of one end of the optical waveguide. The reflected light flux is collected by light-collecting structures and then is made to enter an optical minute aperture formed in the near-field optical head. Near-field light is created near the minute aperture. Light scattered by the surface of the recording medium is received. Thus, information on the recording medium can be recorded and read.
    Type: Application
    Filed: June 21, 2002
    Publication date: January 2, 2003
    Inventors: Yoko Shinohara, Yasuyuki Mitsuoka, Manabu Oumi, Nobuyuki Kasama, Hidetaka Maeda, Kenji Kato, Susumu Ichihara, Takashi Niwa, Toshifumi Ohkubo, Terunao Hirota, Hiroshi Hosaka, Kiyoshi Itao