Patents by Inventor Tohru Kira

Tohru Kira 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: 5995337
    Abstract: A combined thin film magnetic head includes a first yoke magnetic head and a second type MR head a front gap is provided at a front end of the first yoke type MR head, and a second yoke type MR head is provided behind the first yoke type MR head. Consequently, the first yoke type MR head and the second yoke type MR head can be formed on the same substrate through the same process steps, and the number of manufacturing steps can be significantly reduced.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: November 30, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tohru Kira
  • Patent number: 5862021
    Abstract: A magnetoresistive effect device is formed by layering a nonmagnetic Co oxide film, a pinned magnetization layer made of Co, a nonmagnetic layer made of Cu, a free magnetization layer made of NiFe in this order on a substrate made of glass or Si. By arranging the nonmagnetic Co oxide film in contact with the pinned magnetization layer, it is possible to produce a magnetoresistive effect device with a high saturation field and a high sensitivity.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: January 19, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Haruhiko Deguchi, Takaya Nakabayashi, Tomohisa Komoda, Tohru Kira, Noboru Fujita, Kazuhiro Uneyama
  • Patent number: 5402292
    Abstract: A magnetoresistance effect type thin film magnetic head includes a MR element having the electrical resistance changed according to a change in an applied signal magnetic field, a lead electrode for detecting a voltage change generated across the ends of the MR element in which a change in electrical resistance is generated, and high coercive force films for applying a weak magnetic field to the MR element. The high coercive force films are arranged in the proximity of the ends of the MR element and at a predetermined position between the ends. According to this structure, a weak magnetic field is applied in uniform over the entire MR element to facilitate unification of magnetic domain of the MR element even in the case of a long MR element.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: March 28, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tomohisa Komoda, Ryoji Minakata, Tohru Kira, Akiyoshi Fujii, Hiroshi Suzuki, Atsuo Mukai
  • Patent number: 5225951
    Abstract: A thin film magnetic head includes yokes for leading magnetic flux of signals generated from a magnetic recording medium up to a magnetic resistance effect element. The yokes are made of sputtered films having internal compressive stress therein. The internal stress in the yokes which are deleterious to the magnetic properties of the magnetic resistance effect element can be negated or reduced by including a film of material on the yokes for compensating for the internal stresses.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: July 6, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tohru Kira, Kozi Otsuka, Kazuyoshi Imae, Mitsuhiko Yoshikawa, Kengo Shiiba
  • Patent number: 5153980
    Abstract: A thin film magnetic head includes first and second head chips, each of the head chips having a substrate, a reproducing head portion provided in a side edge portion on the substrate, and a protecting plate convering the reproducing head portion and the recording head portion. The reproducing head portion and the recording head portion are formed of a lower magentic layer, an electroconductive coil layer, an upper magnetic layer and insulation layers interposed therebetween, deposited in stacked relation on the substrate one after another.
    Type: Grant
    Filed: July 26, 1991
    Date of Patent: October 13, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tohru Kira
  • Patent number: 5155644
    Abstract: The yoke thin film magnetic head according to the present invention includes yokes for leading the magnetic flux of signals generated from the magnetic recording medium up to the magnetic resistance effect element, which yokes are made of sputtered films having compressive stress therein. Therefore, the internal stress in the yokes which cause bad influences upon magnetic properties of the magnetic resistance effect element can be negated or reduced, with less Barkhausen noises produced.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: October 13, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tohru Kira, Kozi Otsuka, Kazuyoshi Imae, Mitsuhiko Yoshikawa, Kengo Shiiba
  • Patent number: 5068760
    Abstract: A thin film magnetic head includes first and second head chips, each of the head chips having a substrate, a reproducing head portion and a recording head portion provided in a side edge portion on the substrate, and a protecting plate covering the reproducing head portion and the recording head portion. The reproducing head portion and the recording head portion are formed of a lower magnetic layer, an electroconductive coil layer, an upper magnetic layer and insulation layers interposed therebetween, deposited in stacked relation on the substrate one after another.
    Type: Grant
    Filed: June 19, 1989
    Date of Patent: November 26, 1991
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tohru Kira
  • Patent number: 4966648
    Abstract: An improved process for producing a thin film magnetic head includes forming a nonmagnetic material layer over a lower magnetic core layer with an electrically conductive coil layer embedded in the nonmagnetic material layer. It further includes forming an upper magnetic core layer of a predetermined pattern by a specific method over the resultant to provide the thin film magnetic head.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: October 30, 1990
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tsuneo Nakamura, Kazuyoshi Imae, Haruhiko Deguchi, Tohru Kira
  • Patent number: 4789910
    Abstract: A thin film magnetic head which comprises an end portion of a first yoke and an end portion of a second yoke confronting each other through a magnetic gap, and receiving from a recording surface or a recording medium, a magnetic signal, and a magnetic reluctance effect element disposed for magnetic coupling in the course of a magnetic path constituted by the first and second yokes. The thin film magnetic head is characterized in that the first yoke or magnetic reluctance effect element is formed on an application type SiO.sub.2 film which improves the surface roughness of the ground layer.
    Type: Grant
    Filed: April 25, 1986
    Date of Patent: December 6, 1988
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kozi Otsuka, Tohru Kira, Kazuyoshi Imae, Mitsuhiko Yoshikawa
  • Patent number: 4702794
    Abstract: There is disclosed a process for modifying in an oxygen plasma an inert reaction product produced on a Fe-Al-Si alloy back core during a production of a thin film magnetic head utilizing a reactive ion etching (RIE) process. As a result of modifying the reaction product it is made readily soluble in and thus removable by water.
    Type: Grant
    Filed: January 30, 1986
    Date of Patent: October 27, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tsuneo Nakamura, Hidenori Yamasaki, Tohru Kira, Mitsuhiko Yoshikawa
  • Patent number: 4677036
    Abstract: There provides a process for preparing a coil type thin film magnetic head having high density record by planarization differences in level caused by an electroconductive coil holded between upper and lower magnetic cores.
    Type: Grant
    Filed: January 29, 1986
    Date of Patent: June 30, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tsuneo Nakamura, Hidenori Yamasaki, Tohru Kira, Mitsuhiko Yoshikawa