Patents by Inventor Yuzo Yamakawa

Yuzo Yamakawa 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: 8097323
    Abstract: An object of the invention is to write-once record and reproduce, or only reproduce, a mark smaller than the resolution limit; obtain a high level of reproduction performance (CNR and the like); and realize a high level of reproduction durability. In the invention, between a signal reproducing functional layer composed of Sb or Te and a protecting layer there is introduced a thermally stable diffusion preventing layer, and thereby reactions between the signal reproducing functional layer and the protecting layer due to increased temperature can be prevented or suppressed while increasing reproduction durability.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: January 17, 2012
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Takayuki Shima, Yuzo Yamakawa, James Paul Fons, Junji Tominaga
  • Publication number: 20100142362
    Abstract: When a method for increasing density by providing a tracking guide such as a land/groove and introducing a plurality of strings of super-resolution pits into one track thereof is applied to a reproduction-dedicated optical disk, there are problems in that the production cost is increased, the structure is complicated, and the space which can be used for a recording pits is narrowed because of the land/groove structure. In the invention, a concept of group tracking is applied. One track is formed by a plurality of pit strings having a size not greater than the optical resolution limit in the radial direction and a size not less than or not greater than the optical resolution limit or only not greater than the optical resolution limit in the tangential direction.
    Type: Application
    Filed: September 25, 2006
    Publication date: June 10, 2010
    Inventors: Kazuma Kurihara, Yuzo Yamakawa, Takashi Nakano, Junji Tominaga
  • Publication number: 20090269542
    Abstract: An object of the invention is to write-once record and reproduce, or only reproduce, a mark smaller than the resolution limit; obtain a high level of reproduction performance (CNR and the like); and realize a high level of reproduction durability. In the invention, between a signal reproducing functional layer composed of Sb or Te and a protecting layer there is introduced a thermally stable diffusion preventing layer, and thereby reactions between the signal reproducing functional layer and the protecting layer due to increased temperature can be prevented or suppressed while increasing reproduction durability.
    Type: Application
    Filed: August 17, 2007
    Publication date: October 29, 2009
    Inventors: Takayuki Shima, Yuzo Yamakawa, James Paul Fons, Junji Tominaga
  • Patent number: 6970307
    Abstract: An optical near-field generating element is provided with: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening. Alternatively, an optical near-field generating element is provided with a light shielding member, which is placed on an optical path of lights emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light, the shielding member equipped with: a main portion for defining a basic shape of the micro opening; and a protrusion portion protruding from the main portion toward the center of the micro opening.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: November 29, 2005
    Assignee: Pioneer Corporation
    Inventors: Satoshi Sugiura, Yuzo Yamakawa
  • Patent number: 6848115
    Abstract: In an optical recording medium having a super-resolution layer structure using near-field light, comprising a readout layer 3 for forming a light scattering region 9 in the center portion of a laser spot, and a recording layer 5 for receiving near-field light 10 generated from the light scattering region 9 of the readout layer 3, scattering bodies 61 for increasing the generated near-field light are provided while enhancing a scattering effect of the near-field light 10 applied to a mark 51 of the recording layer 5.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: January 25, 2005
    Assignee: Pioneer Corporation
    Inventors: Satoshi Sugiura, Akihiro Tachibana, Yuzo Yamakawa
  • Publication number: 20050008296
    Abstract: An optical near-field generating element is provided with: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening. Alternatively, an optical near-field generating element is provided with a light shielding member, which is placed on an optical path of lights emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light, the shielding member equipped with: a main portion for defining a basic shape of the micro opening; and a protrusion portion protruding from the main portion toward the center of the micro opening.
    Type: Application
    Filed: August 13, 2004
    Publication date: January 13, 2005
    Inventors: Satoshi Sugiura, Yuzo Yamakawa
  • Patent number: 6839191
    Abstract: An optical near-field generating element is provided with: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening. Alternatively, an optical near-field generating element is provided with a light shielding member, which is placed on an optical path of lights emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light, the shielding member equipped with: a main portion for defining a basic shape of the micro opening; and a protrusion portion protruding from the main portion toward the center of the micro opening.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: January 4, 2005
    Assignee: Pioneer Corporation
    Inventors: Satoshi Sugiura, Yuzo Yamakawa
  • Publication number: 20030128945
    Abstract: An optical near-field generating element is provided with: a light shielding member, which is placed on an optical path of light emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light; and a dielectric film placed in close contact with the micro opening. Alternatively, an optical near-field generating element is provided with a light shielding member, which is placed on an optical path of lights emitted from a light source, for defining a micro opening having a diameter equal to or shorter than a wavelength of the light, the shielding member equipped with: a main portion for defining a basic shape of the micro opening; and a protrusion portion protruding from the main portion toward the center of the micro opening.
    Type: Application
    Filed: August 2, 2002
    Publication date: July 10, 2003
    Applicant: PIONEER CORPORA TION
    Inventors: Satoshi Sugiura, Yuzo Yamakawa
  • Publication number: 20020051422
    Abstract: In an optical recording medium having a super-resolution layer structure using near-field light, comprising a readout layer 3 for forming a light scattering region 9 in the center portion of a laser spot, and a recording layer 5 for receiving near-field light 10 generated from the light scattering region 9 of the readout layer 3, scattering bodies 61 for increasing the generated near-field light are provided while enhancing a scattering effect of the near-field light 10 applied to a mark 51 of the recording layer 5.
    Type: Application
    Filed: October 4, 2001
    Publication date: May 2, 2002
    Applicant: PIONEER CORPORATION
    Inventors: Satoshi Sugiura, Akihiro Tachibana, Yuzo Yamakawa
  • Patent number: 5337301
    Abstract: The optical recording medium includes: an information recording substrate; and pits formed on the information recording substrate, each of the pits corresponding to a recording information unit comprising a plurality of bits, and having one of predetermined patterns for respectively generating different optical characteristics by projecting a light spot onto the pits.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: August 9, 1994
    Assignee: Pioneer Electronic Corporation
    Inventors: Satoshi Sugiura, Yuzo Yamakawa