Patents by Inventor Hideki Ishizuki

Hideki Ishizuki 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).

  • Crystal element, method for manufacturing same, and optical oscillation device including crystal element
    Patent number: 11967932
    Abstract: A crystal quartz element includes a main face provided with a plurality of polarity inverted regions and a polarity non-inverted region, the plurality of polarity inverted regions are spaced apart from each other via the polarity non-inverted region, and the main face is a plane face. A method for manufacturing a crystal quartz element includes: preparing a crystal quartz body including a first main face which is a plane face, and a first pressing jig including a first pressing face on which a plurality of first projections are provided; and forming a plurality of polarity inverted regions corresponding to the plurality of first projections in the crystal quartz body by heating and pressing the first main face by the first pressing face.
    Type: Grant
    Filed: July 20, 2020
    Date of Patent: April 23, 2024
    Assignee: INTER-UNIVERSITY RESEARCH INSTITUTE CORPORATION NATIONAL INSTITUTES OF NATURAL SCIENCES
    Inventors: Hideki Ishizuki, Takunori Taira
  • CRYSTAL ELEMENT, METHOD FOR MANUFACTURING SAME, AND OPTICAL OSCILLATION DEVICE INCLUDING CRYSTAL ELEMENT
    Publication number: 20220329205
    Abstract: A crystal quartz element includes a main face provided with a plurality of polarity inverted regions and a polarity non-inverted region, the plurality of polarity inverted regions are spaced apart from each other via the polarity non-inverted region, and the main face is a plane face. A method for manufacturing a crystal quartz element includes: preparing a crystal quartz body including a first main face which is a plane face, and a first pressing jig including a first pressing face on which a plurality of first projections are provided; and forming a plurality of polarity inverted regions corresponding to the plurality of first projections in the crystal quartz body by heating and pressing the first main face by the first pressing face.
    Type: Application
    Filed: July 20, 2020
    Publication date: October 13, 2022
    Applicant: INTER-UNIVERSITY RESEARCH INSTITUTE CORPORATION NATIONAL INSTITUTES OF NATURAL SCIENCES
    Inventors: Hideki ISHIZUKI, Takunori TAIRA
  • Frequency control method and circuit employing both reference symbols and information symbols
    Patent number: 6044119
    Abstract: The frequency of a local oscillator is controlled by demodulating a received signal to obtain received symbol values, determining the data value represented by each received symbol value, removing the data values from the received symbol values, and calculating a frequency adjustment from the remaining values. The received signal has reference symbols with known values interspersed among information symbols. The data values of information symbols are determined by a hard-decision process. Received symbol values are preferably obtained for multiple paths, the frequency adjustment being calculated by combining results for different paths.
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: March 28, 2000
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shinichi Sato, Hideki Ishizuki