Patents by Inventor Mitsuo Suda

Mitsuo Suda 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).

  • Magnetic recording apparatus with magnetic head on slider having applied load larger than buoyant force acting on slider so that gap between magnetic head and magnetic disk is smaller than total thickness of protective layer and lubricating layer on disk
    Patent number: 5541789
    Abstract: A magnetic recording device includes a magnetic disk for storing information, a magnetic head for writing and reading information relative to the magnetic disk, a device for rotating the magnetic disk relative to the magnetic head in such a manner that speed of said magnetic disk relative to the magnetic head is 6 to 40 m/s at an innermost track of the magnetic disk, and a device for applying a load to the magnetic head so that a gap between the magnetic disk and the magnetic head disposed in opposed relation to the magnetic disk can be kept to not more than 0.1 .mu.m.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: July 30, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Hirotsugu Fukuoka, Hiroshi Fukui, Mitsuo Suda, Yutaka Sugita, Kanji Kawakami
  • Magneto-resistance effect type of recording/reproducing head
    Patent number: 5461517
    Abstract: In a magnetic disk device having a composite head with an induction type of recording head adjacent a magneto-resistance effect type of reproducing head, a read error relief is provided to relieve read errors caused by Barkhausen Noise or Base Line Shift phenomenon inherent to the magneto-resistance effect type of reproducing head. Upon occurrence of a read error, a re-try function is first executed, and a track offset function is executed for relief of the read error. However, if the read error is not relieved after the offset operation and the re-try operation have been performed a predetermined number of times, then a pseudo write-in and/or read current control operation is performed together with the offset operation and/or re-try operation for a predetermined number of times. The control operation varies the magnetic domain structure in the head magnetic film (MR film).
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: October 24, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuo Suda, Kazuo Shiiki, Masanori Tanabe, Shinji Narishige, Eiji Nakanishi, Kouichi Shimizu, Norifumi Miyamoto, Hirotsugu Fukuoka
  • Method for making a thin film magnetic head
    Patent number: 4861398
    Abstract: DC bias currents are applied to a conducting wire of a thin film magnetic head to be inspected. When the DC bias currents (I.sub.0, I.sub.1, I.sub.2) are supplied to the conducting wire, the impedances (Z.sub.0, Z.sub.1, Z.sub.2) corresponding to the DC bias currents are measured. When a ratio (.vertline.Z.sub.1 -Z.sub.0 .vertline./.vertline.Z.sub.2 -Z.sub.0 .vertline.) corresponding to an overwrite characteristic (OW) reaches to a predetermined value by lapping tip portions of an upper magnetic layer and a lower magnetic layer of the magnetic head, the lapping process of the magnetic head is finished.
    Type: Grant
    Filed: November 20, 1987
    Date of Patent: August 29, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Hirotsugu Fukuoka, Kanji Kawakami, Makoto Aihara, Mitsuo Suda, Kouji Takeshita, Yukihiro Isono