Patents by Inventor Takumi Haneda

Takumi Haneda 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: 6037037
    Abstract: The present invention provides a thin multilayer magnetic recording medium having improved electromagnetic conversion property and durability, comprising coating layers of a lower non-magnetic layer and an upper magnetic layer. The non-magnetic layer of this magnetic recording medium comprises a non-magnetic needle body having an average major axis length of 0.25 to 1.0 .mu.m and an average minor axis length of 0.005 to 0.0151 .mu.m, a first binding resin having a glass transition temperature (Tg.sub.1) of 30 to 50.degree. C., and fatty acid ester. The content of the first binding resin is 15 to 30 wt % with respect to the non-magnetic needle body. The content of the fatty acid ester is 2 to 15 wt % with respect to the first binding resin. The magnetic layer having a dry thickness of 0.5 .mu.m or less comprises ferromagnetic powder and a second binding resin having a glass transition temperature (Tg.sub.2) of 40 to 70.degree. C. Tg.sub.1 is at least 5.degree. C. lower than Tg.sub.
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: March 14, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazunori Kubota, Fumio Echigo, Yukihiro Shimasaki, Takumi Haneda, Hirofumi Ito, Tetuo Fuchi, Kiyoshi Kobata
  • Patent number: 5503911
    Abstract: A coating film of a double-layer structure for a recording medium is formed by providing a non-magnetic buffer layer just beneath a magnetic recording layer composed of magnetic hexagonal platelet ferrite particles, wherein the thickness of the magnetic recording layer is 0.1-0.6 .mu.m and the ratio of thickness of the buffer layer to that of the magnetic recording layer is 1:1 to 4:1. This coating film makes it possible to realize the excellent medium surface characteristics that could not be obtained with the conventional techniques and to obtain a high recording density excelling those of the conventional in-plane longitudinal recording media.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 2, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nobuyuki Aoki, Yukihiro Shimasaki, Akira Kisoda, Yuji Mido, Takumi Haneda