Patents by Inventor Kyung-Kun CHOI

Kyung-Kun CHOI 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: 9070500
    Abstract: The present invention provides a permanent magnet whose magnetic properties will not be significantly decreased and which is excellent in the temperature properties compared to the existing R-T-B based permanent magnet. In the R-T-B based structure, a stacked structure of R1-T-B based crystallizing layer and (Y, La)-T-B based crystallizing layer can be formed by alternatively stacking R1-T-B and (Y, La)-T-B. In this way, a high magnetic anisotropy field of the R1-T-B based crystallizing layer can be maintained while an improved temperature coefficient of the (Y, La)-T-B based crystallizing layer can be obtained. Further, the lattice distortion in the total stacked structure is moderated by setting the rare earth elements in the (Y, La)-T-B based crystallizing layer as both of Y and La, and a high residual flux density can be obtained accordingly.
    Type: Grant
    Filed: April 21, 2014
    Date of Patent: June 30, 2015
    Assignee: TDK CORPORATION
    Inventors: Ryuji Hashimoto, Kenichi Suzuki, Kyung-Kun Choi
  • Publication number: 20140320244
    Abstract: The present invention provides a permanent magnet whose magnetic properties will not be significantly decreased and which is excellent in the temperature properties compared to the existing R-T-B based permanent magnet. In the R-T-B based structure, a stacked structure of R1-T-B based crystallizing layer and (Y, La)-T-B based crystallizing layer can be formed by alternatively stacking R1-T-B and (Y, La)-T-B. In this way, a high magnetic anisotropy field of the R1-T-B based crystallizing layer can be maintained while an improved temperature coefficient of the (Y, La)-T-B based crystallizing layer can be obtained. Further, the lattice distortion in the total stacked structure is moderated by setting the rare earth elements in the (Y, La)-T-B based crystallizing layer as both of Y and La, and a high residual flux density can be obtained accordingly.
    Type: Application
    Filed: April 21, 2014
    Publication date: October 30, 2014
    Applicant: TDK CORPORATION
    Inventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-Kun CHOI