Patents by Inventor Yuichi Arisaka

Yuichi Arisaka 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: 5571595
    Abstract: A magnetic recording medium having a magnetic metal thin film as a magnetic layer is disclosed. An oxide layer is formed on the surface of the magnetic metal thin film, and a proactive layer is further formed on the oxide layer. The oxide layer on the surface of the magnetic metal thin film has a thickness of 20 to 230 .ANG., while the protective layer has a thickness of 20 to 230 .ANG.. The combined total thickness of the oxide layer and the protective layer is 40 to 250 .ANG.. The oxide layer surface may be bombarded prior to formation of the protective layer for improving the bonding of the protective layer. A lubricant may be coated on the surface of the protective layer. The lubricant may be one of perfluoro alkyl ester of carboxylic acid, ester compounds of perfluoro polyether having carboxylic groups, and amine salt compounds. The reverse surface of a non-magnetic base film as a substrate has a centerline mean roughness R.sub.a and the maximum height R.sub.max of projections in the ranges of 0.015 .mu.
    Type: Grant
    Filed: November 26, 1993
    Date of Patent: November 5, 1996
    Assignee: Sony Corporation
    Inventors: Kazunobu Chiba, Kenichi Sato, Yuichi Arisaka, Hirofumi Kondo, Yukari Yamada
  • Patent number: 5512349
    Abstract: A magnetic tape for the recording of digital video signals is constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 100 G.cm.Oe, and with the surface roughness of the magnetic tape being at most 0.003 .mu.m in center line average height. Such tape, when used with magnetic heads each having a gap defined between portions of the respective head having a saturation magnetic flux density of at least 14 kG., contribute to the maintenance of an acceptable raw error bit rate below 1.times.10.sup.-4 when recording with a recorded bit area of no more than 1.25 .mu.m.sup.2 /bit.
    Type: Grant
    Filed: March 30, 1994
    Date of Patent: April 30, 1996
    Assignee: Sony Corporation
    Inventors: Kazunobu Chiba, Kenichi Sato, Yuichi Arisaka
  • Patent number: 5347406
    Abstract: A magnetic tape for the recording of digital video signals is constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 100 G.cm.Oe, and with the surface roughness of the magnetic tape being at most 0.003 .mu.m in center line average height. Such tape, when used with magnetic heads each having a gap defined between portions of the respective head having a saturation magnetic flux density of at least 14 kG., contribute to the maintenance of an acceptable raw error bit rate below 1.times.10.sup.-4 when recording with a recorded bit area of no more than 1.25 .mu.m.sup.2 /bit.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: September 13, 1994
    Assignee: Sony Corporation
    Inventors: Kazunobu Chiba, Kenichi Sato, Yuichi Arisaka
  • Patent number: 5253122
    Abstract: A magnetic tape for the recording of digital video signals is constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 100 G.cm.Oe, and with the surface roughness of the magnetic tape being at most 0.003 .mu.m in center line average height. Such tape, when used with magnetic heads each having a gap defined between portions of the respective head having a saturation magnetic flux density of at least 14 kG., contribute to the maintenance of an acceptable raw error bit rate below 1.times.10.sup.-4 when recording with a recorded bit area of no more than 1.25 .mu.m.sup.2 /bit.
    Type: Grant
    Filed: October 30, 1991
    Date of Patent: October 12, 1993
    Assignee: Sony Corporation
    Inventors: Kazunobu Chiba, Kenichi Sato, Yuichi Arisaka
  • Patent number: 5247397
    Abstract: A magnetic recording transfer method for use with the combination of a mother magnetic recording medium and a copy magnetic recording medium of a metal-deposited thin film type each. The two media are overlaid so that the column inclination of one medium will be opposite in direction to that of the other medium. This method comprises the step of externally applying a biased magnetic field to the combination of the media in such a manner that magnetized recordings on the mother medium will be transferred to the copy medium. The easy axis of the mother medium is positioned at an angle of 20.degree..+-.15.degree. with respect to the in-plane direction of the medium. The biased magnetic field is applied to the mother medium at an angle of 110.degree..+-.15.degree. with respect to the in-plane direction of the medium.
    Type: Grant
    Filed: October 23, 1991
    Date of Patent: September 21, 1993
    Assignee: Sony Corporation
    Inventors: Kenichi Sato, Kazunobu Chiba, Yuichi Arisaka, Toshiharu Kobayashi, Yukari Yamada