Patents by Inventor Takahiko Machita

Takahiko Machita 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: 20070109691
    Abstract: A thin-film magnetic head comprises: a magnetoresistive element: first and second read shield layers disposed to sandwich the magnetoresistive element; and bias field applying layers for applying a bias magnetic field to the magnetoresistive element. Each of the first and second read shield layers has: a first end face located in a medium facing surface; a second end face opposite to the first end face; a first width changing portion that continuously decreases in width as the distance from the first end face decreases; and a second width changing portion that continuously decreases in width as the distance from the second end face decreases.
    Type: Application
    Filed: July 7, 2006
    Publication date: May 17, 2007
    Applicant: TDK Corporation
    Inventors: Takahiko Machita, Kei Hirata, Koji Shimazawa
  • Publication number: 20060262457
    Abstract: A magnetic field sensor comprises: a magnetic field detecting element that detects magnitude of an external magnetic field based on electric resistance of the magnetic field detecting element to sense current, the electric resistance being varied in accordance with the external magnetic field; an upper shield layer that is formed to cover the magnetic field detecting element; and a protective layer that is formed above the upper shield layer with respect to a direction of stacking. The upper shield layer includes a first portion at least part of which covers a top surface of the magnetic field detecting element, and a second portion that covers the first portion, and, the first portion has a larger absolute value of magnetostriction than the second portion.
    Type: Application
    Filed: April 26, 2006
    Publication date: November 23, 2006
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Takahiko Machita, Koji Shimazawa, Kiyoshi Noguchi
  • Publication number: 20060203379
    Abstract: A perpendicular magnetic recording element includes a recording magnetic pole film and a write shield film. The recording magnetic pole film has a yoke portion and a main magnetic pole for perpendicular recording. The main magnetic pole projects from a front end of the yoke portion to have an end on a medium-facing surface. The write shield film faces the recording magnetic pole film and has a height equal to or smaller than that of the recording magnetic pole film, as measured rearward from the medium-facing surface.
    Type: Application
    Filed: January 24, 2006
    Publication date: September 14, 2006
    Applicant: TDK Corporation
    Inventors: Kei Hirata, Takahiko Machita, Kiyoshi Noguchi
  • Publication number: 20050231856
    Abstract: A GMR read pillar formed by ion milling has both vertical and sloping sidewall sections with the free layer normally being located within the latter. Using xenon as the sputtering gas enables the vertical section of the pedestal to be made longer, relative to the sloping portion, without requiring an increase in the sputtering rate, so the free layer can have vertical sidewalls. This allows the point at which milling is terminated to be controlled more precisely and, by more precisely defining the width of the free layer, also improves design tolerances.
    Type: Application
    Filed: April 20, 2004
    Publication date: October 20, 2005
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jeiwei Chang
  • Publication number: 20050219766
    Abstract: An MR element incorporates: a nonmagnetic conductive layer having two surfaces facing toward opposite directions; a free layer disposed adjacent to one of the surfaces of the nonmagnetic conductive layer, wherein the direction of magnetization in the free layer changes in response to an external magnetic field; and a pinned layer disposed adjacent to the other of the surfaces of the nonmagnetic conductive layer, wherein the direction of magnetization in the pinned layer is fixed to the direction orthogonal to the air bearing surface. The MR element does not include any layer provided for fixing the direction of magnetization in the pinned layer. The pinned layer incorporates a ferromagnetic layer made of a ferromagnetic material having a positive magnetostriction constant. A bottom shield gap film and a top shield gap film disposed adjacent to the MR element each have a compressive stress of 600 MPa or greater.
    Type: Application
    Filed: March 14, 2005
    Publication date: October 6, 2005
    Applicant: TDK CORPORATION
    Inventors: Takahiko Machita, Koji Shimazawa
  • Publication number: 20050213261
    Abstract: A read head comprises: a bottom shield layer; a top shield layer; an MR element disposed between the bottom shield layer and the top shield layer; a bottom shield gap film disposed between the bottom shield layer and the MR element; and a top shield gap film disposed between the top shield layer and the MR element. The MR element has a first end closer to the air bearing surface and a second end opposite to the first end. An adjacent layer made of a metal material is adjacent to the second end with an insulating film disposed in between. The material making up the adjacent layer has a linear thermal expansion coefficient whose absolute value is 6×10?6/° C. or smaller at a temperature of 30° C., and preferably 1×10?6/° C. or smaller.
    Type: Application
    Filed: March 7, 2005
    Publication date: September 29, 2005
    Applicant: TDK CORPORATION
    Inventors: Takahiko Machita, Koji Shimazawa