Patents by Inventor Masatoshi Hashimoto

Masatoshi Hashimoto 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).

  • Magneto-optical recording medium and process for producing the same
    Patent number: 5783320
    Abstract: Disclosed is a magneto-optical recording medium which comprises a transparent substrate and, provided on the substrate, a magneto-optical recording film comprising a perpendicular magnetic film based on rare earth metal-transition metal and an auxiliary magnetic film having spontaneous magnetization which exerts, between itself and the magneto-optical recording film, an exchange coupling force on each other and in which the auxiliary magnetic film used is a magnetic film which readily rotates its magnetization direction toward the external magnetic field in the neighborhood of the Curie temperature of the magneto-optical recording film and has a squareness ratio of not more than 1 in the neighborhood of the Curie temperature, and a process for producing the magneto-optical recording medium.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: July 21, 1998
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Katsusuke Shimazaki, Satoru Ohnuki, Masatoshi Hashimoto, Yoshinori Shirai, Norio Ohta, Hideo Fujiwara, Masafumi Yoshihiro, Yukinori Yamada, Eiji Koyama, Hitoshi Furusho
  • Magneto-optical recording medium and process for producing the same
    Patent number: 5637411
    Abstract: Disclosed is a magneto-optical recording medium which comprises a transparent substrate and, provided on the substrate, a magneto-optical recording film comprising a perpendicular magnetic film based on rare earth metal-transition metal and an auxiliary magnetic film having spontaneous magnetization which exerts, between itself and the magneto-optical recording film, an exchange coupling force and wherein the auxiliary magnetic film is a magnetic film which readily rotates its magnetization direction toward the external magnetic field in the neighborhood of the Curie temperature of the magneto-optical recording film and has a squareness ratio of not more than 1 in the neighborhood of the Curie temperature. Also disclosed is a process for producing the magneto-optical recording medium.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: June 10, 1997
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Katsusuke Shimazaki, Satoru Ohnuki, Masatoshi Hashimoto, Yoshinori Shirai, Norio Ohta, Hideo Fujiwara, Masafumi Yoshihiro, Yukinori Yamada, Eiji Koyama, Hitoshi Furusho