Patents by Inventor Katsuya Mitsuoka

Katsuya Mitsuoka 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: 8064159
    Abstract: One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: November 22, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Koji Sakamoto, Koichi Nishioka, Katsuya Mitsuoka, Katsumi Hoshino, Yo Sato
  • Publication number: 20100157465
    Abstract: One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Inventors: Koji Sakamoto, Koichi Nishioka, Katsuya Mitsuoka, Katsumi Hoshino, Yo Sato
  • Patent number: 6633465
    Abstract: A magnetoresistive element includes a first antiferromagnetic film, a first magnetic film having a magnetization direction fixed by magnetic coupling with the first antiferromagnetic film, a second antiferromagnetic film, a second magnetic film having a magnetization direction fixed by magnetic coupling with the second antiferromagnetic film, a third magnetic film having a magnetization direction able to rotate in response to an applied magnetic field, a first nonmagnetic film disposed between the first magnetic film and the third magnetic film, and a second nonmagnetic film disposed between the second magnetic film and the third magnetic film. The third magnetic film is disposed between the first nonmagnetic film and the second nonmagnetic film, the first magnetic film is disposed between the first antiferromagnetic film and the first nonmagnetic film, and the second magnetic film is disposed between the second antiferromagnetic film and the second nonmagnetic film.
    Type: Grant
    Filed: April 25, 2001
    Date of Patent: October 14, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsuya Mitsuoka, Masaaki Sano, Reiko Arai, Susumu Soeya, Hiroshi Fukui, Moriaki Fuyama, Fumio Sato
  • Publication number: 20010017752
    Abstract: A magnetoresistive element includes a first antiferromagnetic film, a first magnetic film having a magnetization direction fixed by magnetic coupling with the first antiferromagnetic film, a second antiferromagnetic film, a second magnetic film having a magnetization direction fixed by magnetic coupling with the second antiferromagnetic film, a third magnetic film having a magnetization direction able to rotate in response to an applied magnetic field, a first nonmagnetic film disposed between the first magnetic film and the third magnetic film, and a second nonmagnetic film disposed between the second magnetic film and the third magnetic film. The third magnetic film is disposed between the first nonmagnetic film and the second nonmagnetic film, the first magnetic film is disposed between the first antiferromagnetic film and the first nonmagnetic film, and the second magnetic film is disposed between the second antiferromagnetic film and the second nonmagnetic film.
    Type: Application
    Filed: April 25, 2001
    Publication date: August 30, 2001
    Inventors: Hiroyuki Hoshiya, Katsuya Mitsuoka, Masaaki Sano, Reiko Arai, Susumu Soeya, Hiroshi Fukui, Moriaki Fuyama, Fumio Sato
  • Patent number: 6249405
    Abstract: A magnetic storage/read system includes a recording medium having tracks, and a magnetic head, including a magnetoresistive element, which reads a magnetic field from the recording medium. The magnetic storage/read system satisfies a relationship of d≦(12.5×103)/Tr where d is a height, expressed in &mgr;m, of the magnetoresistive element in a direction perpendicular to a plane of the recording medium, and Tr is a track density, expressed in tracks per inch, of the tracks of the recording medium.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: June 19, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsuya Mitsuoka, Masaaki Sano, Reiko Arai, Susumu Soeya, Hiroshi Fukui, Moriaki Fuyama, Fumio Sato
  • Patent number: 6125019
    Abstract: A magnetic head includes a magnetoresistive element. The magnetoresistive element includes a first magnetic film having a fixed magnetization direction, a second magnetic film having a fixed magnetization direction, a third magnetic film having a rotatable magnetization direction, a first nonmagnetic film, and a second nonmagnetic film. The first magnetic film, the first nonmagnetic film, the third magnetic film, the second nonmagnetic film, and the second magnetic film are stacked in this order.
    Type: Grant
    Filed: August 3, 1999
    Date of Patent: September 26, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsuya Mitsuoka, Masaaki Sano, Reiko Arai, Susumu Soeya, Hiroshi Fukui, Moriaki Fuyama, Fumio Sato
  • Patent number: 5933297
    Abstract: A magnetic storage/read system includes a recording medium for magnetically storing a signal and a magnetoresistive element which is driven relative to the recording medium. The magnetoresistive element may include a substrate, a first antiferromagnetic film, a first ferromagnetic film, a first nonmagnetic film, a soft magnetic film, a second nonmagnetic film, a second ferromagnetic film, and a second antiferromagnetic film, wherein the films are sequentially layered directly on the substrate with no intervening layer between any of the films. At least one of the first antiferromagnetic film and the second antiferromagnetic film may be made of nickel oxide.
    Type: Grant
    Filed: April 13, 1993
    Date of Patent: August 3, 1999
    Assignee: Hitach, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsuya Mitsuoka, Masaaki Sano, Reiko Arai, Susumu Soeya, Hiroshi Fukui, Moriaki Fuyama, Fumio Sato
  • Patent number: 5671107
    Abstract: A magnetic disc apparatus has a large recording density of 120 megabits per square inch or more, and defines a relationship among a pole thickness (Pt) of thin-film magnetic heads disposed in the magnetic disc apparatus, and a saturation flux density (Bs) of cores of the heads and a recording wavelength (.lambda.) for the thin film magnetic discs have a coercivity of 1800 Oe or more, wherein a levitation space between the head and the disc is 0.15 .mu.m or less.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: September 23, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Katsuya Mitsuoka, Hiroshi Fukui, Makoto Aihara, Masanori Tanabe, Moriaki Fuyama, Shinji Narishige, Yutaka Sugita, Yoshihiro Shiroishi, Hajime Aoi, Yokuo Saitoh, Kanji Kawakami, Yoshikazu Tsuji, Masaaki Hayashi, Kazuo Nakagoshi
  • Patent number: 5639547
    Abstract: A magnetic lamination including at least a first magnetic film, a second magnetic film and, a third magnetic film, a first intervening intermediate film intervening between the first and second magnetic films, and a second intervening intermediate film intervening between the second and third magnetic films, wherein the respective magnetic films each comprise a magnetically soft film, the first and second intervening films differ in thickness, and one of the first and second intervening films can have a zero thickness and further, the intervening intermediate film can include a transition metal and a substance which is likely to form a heterogeneous mixture with the transition metal.
    Type: Grant
    Filed: April 9, 1993
    Date of Patent: June 17, 1997
    Assignees: Hitachi Maxell, Ltd., Hitachi Ltd.
    Inventors: Katsuya Mitsuoka, Yutaka Sugita, Hideo Fujiwara
  • Patent number: 5590008
    Abstract: A magnetic disc unit has a thin film magnetic head in which a lower magnetic core and an upper magnetic core form a magnetic circuit. The upper magnetic core is constructed by magnetic films having at least two layers. A saturation magnetic flux density of the inside magnetic film, of the magnetic films having at least two layers, facing a magnetic gap of the magnetic circuit is larger than that of the outside magnetic films of the upper magnetic core and the lower magnetic core.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: December 31, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tanabe, Hiroshi Fukui, Tadayuki Iwakura, Kazuhiro Nakamoto, Moriaki Fuyama, Katsuya Mitsuoka, Masaaki Sano, Makoto Saito, Makoto Aihara, Shuji Sudo
  • Patent number: 5563752
    Abstract: A magnetic recording and reproducing device using a giant magnetoresistive film for providing high detection sensitivity. In the giant magnetoresistive film comprising a conductive nonmagnetic film, first and second conductive ferromagnetic films, a magnetization fixing film for fixing a magnetization direction of the first ferromagnetic film, and a pair of electrodes for making a detection current flow, when no external magnetic field is received and no detection current flows, a magnetization direction of the second ferromagnetic film is made non-orthogonal to the magnetization direction of the first ferromagnetic film. Magnitude of the detection current is determined so that when no external magnetic field is received and detection current flows, they are orthogonal to each other upon receipt of a magnetic field due to the detection current.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: October 8, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Hiroyuki Hoshiya, Katsuya Mitsuoka, Hiroshi Fukui, Hirotsugu Fukuoka, Moriaki Fuyama
  • Patent number: 5307214
    Abstract: A magnetic recording apparatus for recording information on a magnetic recording medium. A circuit for generates a recording current pulse train and supplies the pulse train to a magnetic head. The last pulse of the recording current pulse train dampled waveform. A ripple current is superposed on the damped waveform.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: April 26, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Kanji Kawakami, Yoshiakira Karakama, Masayuki Takagi, Takayoshi Ohtsu, Hisayasu Honma, Tetsuo Kobayashi, Yutaka Sugita, Katsuya Mitsuoka
  • Patent number: 5214840
    Abstract: A method of fabricating a thin film magnetic head including a bottom magnetic core formed on a substrate, a top magnetic core laminated through an insulation layer, with one end of the top and bottom magnetic cores being joined and another end forming a magnetic gap, and a conductor coil layer which winds around the joined section for a plurality of number of turns. At least one of the top and bottom magnetic cores has its magnetization easy axis oriented substantially orthogonal to the magnetic path direction of the magnetic head by the magnetic annealing process, so that the magnetic head has an increased output and an enhanced write ability.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: June 1, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Takao Imagawa, Masaaki Sano, Katsuya Mitsuoka, Kouichi Nishioka, Shinji Narishige, Tetsuo Kobayashi
  • Patent number: 5051856
    Abstract: A thin film magnetic head has magnetic films, at least one of which is composed of a material containing major components of nickel and iron and one or more element from nitrogen, oxygen and carbon and has two of face-centered cubic system and body-centered tetragonal system, whereby thin film magnetic heads having a high permeability and low coercive force can be provided.
    Type: Grant
    Filed: October 12, 1989
    Date of Patent: September 24, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Shinji Narishige, Katsuya Mitsuoka, Takao Imagawa, Kouichi Nishioka, Akira Kumagai, Masaaki Sano, Yutaka Sugita, Reiko Arai, Tetsuo Kobayashi, Toshihiro Yoshida, Yokuo Saitoh, Yoshikazu Tsuji, Masaaki Hayashi
  • Patent number: 4780781
    Abstract: A thin film magnetic head comprising a lower magnetic film, an upper magnetic film which is formed over the lower magnetic film and in which one end is come into contact with one end of the lower magnetic film and the other end faces the other end of the lower magnetic film through a magnetic gap and thereby forming a magnetic circuit which has a magnetic gap in a part thereof, together with the lower magnetic film, and a conductor coil forming a coil of a predetermined number of turns and passing between the upper and lower magnetic films and crossing the magnetic circuit. Each of the upper and lower magnetic films is formed of a Co-Ni-Fe ternary alloy having a face-centered cubic crystal structure. Also, uniaxial anisotropy is alternately and perpendicularly given in every layer of a predetermined thickness stacked in the direction of thickness of the film.
    Type: Grant
    Filed: September 24, 1985
    Date of Patent: October 25, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Masaaki Sano, Katsuya Mitsuoka, Makoto Morijiri, Shinji Narishige, Masanobu Hanazono, Toshihiro Yoshida
  • Patent number: 4626947
    Abstract: A thin film magnetic head comprises a lower magnetic member and an upper magnetic film which constitute a magnetic circuit having a magnetic gap at a predetermined location, and a conductor film forming a coil which intersects the magnetic circuit. At least the upper magnetic film has a magnetostriction constant which is not greater than 6.times.10.sup.-7 in the absolute value.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: December 2, 1986
    Assignee: Computer Basic Technology Research Association
    Inventors: Shinji Narishige, Tsuneo Yoshinari, Mituo Sato, Masayuki Takagi, Sadanori Nagaike, Toshihiro Yoshida, Katsuya Mitsuoka
  • Patent number: 4623439
    Abstract: A magnetic thin film of Ni-Co-Fe ternary alloy containing at most 75% by weight of Ni, 10 to 90% by weight of Co, and at most 15% by weight of Fe, which shows the magnetostriction constant between +2.times.10.sup.-6 to -2.times.10.sup.-6 and shows a uniaxial magnetic anisotropy of at most 10 Oe.The film is formed through the vacuum evaporation of the alloy during which two orthogonal external magnetic fields, directions x and y, are alternately applied over the deposition surface of a substrate.The film is suitable for a core material of a thin film magnetic head with a higher recording density.
    Type: Grant
    Filed: October 5, 1984
    Date of Patent: November 18, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Katsuya Mitsuoka, Shinji Narishige, Akira Kumagai, Masaaki Sano, Shinichi Hara, Masanobu Hanazono
  • Patent number: 4592801
    Abstract: A method of patterning a thin film by dry etching is disclosed in which, in order for a thin alumina film to have a predetermined pattern, the thin alumina film is selectively removed by carrying out the ion beam etching which uses a carbon fluoride gas, while using a photoresist film as a mask.
    Type: Grant
    Filed: August 9, 1984
    Date of Patent: June 3, 1986
    Assignee: Computer Basic Technology Research Association
    Inventors: Shinichi Hara, Shinji Narishige, Tsuneo Yoshinari, Mistuo Sato, Katsuya Mitsuoka, Makoto Morijiri, Masanobu Hanazono, Tetsuo Kobayashi