Patents by Inventor Akira Morinaga

Akira Morinaga 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).

  • Publication number: 20040223263
    Abstract: Magneto-resistive effect head arrangements, including a single magnetic domain control layer made of plural layers.
    Type: Application
    Filed: February 5, 2004
    Publication date: November 11, 2004
    Inventors: Akira Morinaga, Koichi Nishioka, Takayoshi Ohtsu, Norifumi Miyamoto, Shuichi Kojima
  • Publication number: 20040174640
    Abstract: In a narrow magnetoresistive head having a magnetic domain control film comprising a single layer of magnetic film or magnetic films antiferromagnetically coupled by means of a nonmagnetic member, it has been found that the magnetic domain can be controlled with a smaller magnetization film thickness product than anticipated so far and the range is defined relative to the geometrical track width in the present invention. By defining the magnetization film thickness product of the magnetic domain control film within a prescribed range of the invention, a magnetic head having higher output than usual and having stable output with no hysteresis in the transfer curve and with no output fluctuation can be attained.
    Type: Application
    Filed: February 24, 2004
    Publication date: September 9, 2004
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Akira Morinaga, Chiaki Ishikawa, Norifumi Miyamoto
  • Publication number: 20040145836
    Abstract: In a magnetoresistive head according to the present invention, a magnetic domain control film formed at the end of a free layer of a stack of magnetoresistive layers is formed of a Co alloy film, and an underlayer controlling the crystallization state of the Co alloy film and an amorphous metal film layer for controlling the crystallization state of the underlayer are disposed below the magnetic domain control film.
    Type: Application
    Filed: September 16, 2003
    Publication date: July 29, 2004
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Shuichi Kojima, Norihiro Ookawa, Koji Okazaki, Yasunobu Yanagisawa, Akira Morinaga
  • Patent number: 6704177
    Abstract: A magneto-resistive effect head includes a magnetic domain control construction using both of an antiferromagnetic film and a magnetic domain control layer made of a magnet layer. The head is constructed by: an antiferromagnetic layer; a pinned layer which is formed on the antiferromagnetic layer and whose magnetizing direction has been fixed; a spacer formed on the pinned layer; a free layer formed on the spacer; magnetic domain control layers having antiferromagnetic films and magnet layers for performing a magnetic domain control of the free layer; and a pair of lead layers for supplying a current to a stack of the antiferromagnetic layer, pinned layer, spacer, and free layer. Thus, even for realization of a narrow track, a magneto-resistive effect head having large sensitivity and small side reading can be realized.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: March 9, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Akira Morinaga, Takayoshi Ohtsu
  • Publication number: 20030189802
    Abstract: The invention provides a magnetic domain controlling structure wherein a lamination stack M1 adjacent to a magnetoresistive stack of a GMR, CPP-GMR or TMR magnetic head has at least two magnetic films 14 and 16 anti-ferromagnetically coupled through a non-magnetic film 15, or the lamination stack M2 disposed on the end portions of the free layer of the magnetoresistive stack of the GMR magnetic head has a magnetic layer anti-ferromagnetically coupled to the free layer 2 through the non-magnetic film 27. Ferromagnetic film deposition dead zone area problems and the consequent problem of film rippling in free layer portions that reduces element sensitivity are prevented, as is the problem of increased error from read drift in the magnetic field exchange coupling method, resulting in a highly stable, highly sensitive MR head with no loss of magnetic field intensity.
    Type: Application
    Filed: August 14, 2002
    Publication date: October 9, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Akira Morinaga, Koichi Nishioka, Takayoshi Ohtsu, Norifumi Miyamoto, Shuichi Kojima
  • Publication number: 20030189799
    Abstract: A magnetoresistive reproducing head is manufactured by forming a magnetoresistive film and a lead layer continuously, then etching only the lead layer by using a first layer photo-resist pattern, forming a second layer photo-resistive pattern while leaving the first layer photo-resist pattern, etching the magnetoresistive film and then forming a domain control film and an outer lead layer, thereby enabling to avoid the effect at all on the positional relation between the lead layer and domain control film, whereby a head in which the riding amount of the lead layer on the magnetoresistive film is in right-to-left symmetry and the sensitivity profile is in right-to-left symmetry can be manufactured at a good yield.
    Type: Application
    Filed: August 16, 2002
    Publication date: October 9, 2003
    Inventors: Yasunobu Yanagisawa, Akira Morinaga, Masatoshi Arasawa, Shuichi Kojima, Makoto Morijiri
  • Publication number: 20030076635
    Abstract: A magneto-resistive effect head includes a magnetic domain control construction using both of an antiferromagnetic film and a magnetic domain control layer made of a magnet layer. The head is constructed by: an antiferromagnetic layer; a pinned layer which is formed on the antiferromagnetic layer and whose magnetizing direction has been fixed; a spacer formed on the pinned layer; a free layer formed on the spacer; magnetic domain control layers having antiferromagnetic films and magnet layers for performing a magnetic domain control of the free layer; and a pair of lead layers for supplying a current to a stack of the antiferromagnetic layer, pinned layer, spacer, and free layer. Thus, even for realization of a narrow track, a magneto-resistive effect head having large sensitivity and small side reading can be realized.
    Type: Application
    Filed: February 15, 2002
    Publication date: April 24, 2003
    Inventors: Akira Morinaga, Takayoshi Ohtsu