Patents by Inventor Masaaki Katayama

Masaaki Katayama 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: 5772797
    Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b<20 and 0<c<22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .gamma.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.
    Type: Grant
    Filed: January 2, 1997
    Date of Patent: June 30, 1998
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 5421915
    Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b.ltoreq.20 and 0<c.ltoreq.22 except the range of b.ltoreq.7.5 and c.ltoreq.5, exhibits low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .lambda.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: June 6, 1995
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
  • Patent number: 5117321
    Abstract: A soft magnetic thin micro-crystalline film of Fe.sub.a B.sub.b N.sub.c (at %) wherein B is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and O<b.ltoreq.20 and O<c.ltoreq.22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition of 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .lambda.s= .Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.
    Type: Grant
    Filed: January 26, 1990
    Date of Patent: May 26, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura