Patents by Inventor Tsutomu Chou

Tsutomu Chou 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: 8654617
    Abstract: The thermally-assisted magnetic recording head includes: a laser light source having an emission surface, the emission surface allowing laser light to be emitted therefrom; a waveguide having a core and a cladding, the core allowing the laser light emitted from the laser light source to propagate therethrough, and the cladding surrounding the core; a magnetic pole; and a plasmon generator. Each of the core and the cladding has an end surface facing the emission surface, and the end surface of the cladding suppresses returning of the laser light to the laser light source.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: February 18, 2014
    Assignees: TDK Corporation, Sae Magnetics (H.K.) Ltd.
    Inventors: Eiji Komura, Tsutomu Chou, Koji Shimazawa, Shinji Hara, Ryo Hosoi, Nobuyuki Mori, Yasutoshi Fujita, Hideki Tanzawa
  • Patent number: 8593766
    Abstract: A magneto-resistive effect (MR) element includes first and second magnetic layers in which a relative angle formed by magnetization directions changes responsive to an external magnetic field, and a spacer layer positioned between the first and second magnetic layers. The first magnetic layer is positioned closer to a substrate above which the MR element is formed than the second magnetic layer. The spacer layer includes copper and metal intermediate layers and a main spacer layer composed primarily of gallium oxide. The copper and metal intermediate layers are positioned between the main spacer and first magnetic layers. The metal intermediate layer is positioned between the copper and main spacer layers. The metal intermediate layer is composed primarily of at least one from a group of one of magnesium and at least partially oxidized magnesium, and one of aluminum and at least partially oxidized aluminum.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: November 26, 2013
    Assignee: TDK Corporation
    Inventors: Yoshihiro Tsuchiya, Tsutomu Chou, Hironobu Matsuzawa, Hayato Koike
  • Patent number: 8578593
    Abstract: A method of manufacturing a thermally-assisted magnetic write head is provided. The method includes steps of: forming a laminate structure including the waveguide; the plasmon generator, and the magnetic pole in order; performing a first polishing process to planarize an end surface of the laminate structure; performing a first etching process to remove impurity attached on the end surface of the laminate structure, and to allow the plasmon generator to be recessed from the waveguide and the magnetic pole, thereby forming a recessed region on the end surface of the laminate structure; forming a protection layer on the end surface of the laminate structure such that at least the recessed region is filled; and performing a second polishing process on the end surface of the laminate structure formed with the protection layer until the plasmon generator is exposed, thereby completing the air bearing surface.
    Type: Grant
    Filed: October 12, 2010
    Date of Patent: November 12, 2013
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Kosuke Tanaka, Shinji Hara, Tsutomu Chou, Yasutoshi Fujita
  • Patent number: 8570843
    Abstract: The present invention provides a thermally assisted magnetic head with improved recording performance. The thermally assisted magnetic head includes a recording element and a near-field light generating element. The recording element includes a main pole appearing on a medium-facing surface, and a bit inversion starting region intended to be a maximum recording magnetic field generating position is formed at a leading edge of the main pole. The near-field light generating element is located on a leading side of the main pole and capable of creating a heating spot due to a near-field light on a near-field light generating end face appearing on the medium-facing surface. The bit inversion starting region is located within one-half of a diameter of the heating spot from a center of the heating spot.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: October 29, 2013
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Kosuke Tanaka, Tsutomu Chou, Susumu Aoki, Makoto Isogai, Tetsuya Roppongi
  • Patent number: 8564911
    Abstract: A magneto-resistive effect (MR) element includes: first and second magnetic layers in which a relative angle formed by magnetization directions changes according to an external magnetic field; and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer includes a main spacer layer composed of gallium oxide as a primary component and containing at least one metal element selected from a group of magnesium, zinc, indium and aluminum.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: October 22, 2013
    Assignee: TDK Corporation
    Inventors: Hayato Koike, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
  • Publication number: 20130258824
    Abstract: A thermal assisted magnetic recording head includes a dielectric waveguide that is configured to propagate propagation light a metal waveguide that is provided facing the dielectric waveguide and that couples to the propagation light propagating through the dielectric waveguide in a surface plasmon mode, thereby generating and propagating surface plasmon, a near-field light generator that is exposed on an air bearing surface facing a magnetic recording medium either at an end part of the metal waveguide or at a position facing the end part of the metal waveguide, and that generates near-field light from the surface plasmon, a magnetic pole for magnetic recording that is exposed on the air bearing surface, and a temperature sensor that is arranged inside the dielectric waveguide.
    Type: Application
    Filed: March 28, 2012
    Publication date: October 3, 2013
    Applicant: TDK Corporation
    Inventors: Eiji KOMURA, Koji SHIMAZAWA, Tsutomu CHOU, Shinji HARA, Kosuke TANAKA, Ryo HOSOI
  • Patent number: 8547805
    Abstract: A thermal assisted magnetic recording head includes a dielectric waveguide that is configured to propagate propagation light a metal waveguide that is provided facing the dielectric waveguide and that couples to the propagation light propagating through the dielectric waveguide in a surface plasmon mode, thereby generating and propagating surface plasmon, a near-field light generator that is exposed on an air bearing surface facing a magnetic recording medium either at an end part of the metal waveguide or at a position facing the end part of the metal waveguide, and that generates near-field light from the surface plasmon, a magnetic pole for magnetic recording that is exposed on the air bearing surface, and a temperature sensor that is arranged inside the dielectric waveguide.
    Type: Grant
    Filed: March 28, 2012
    Date of Patent: October 1, 2013
    Assignee: TDK Corporation
    Inventors: Eiji Komura, Koji Shimazawa, Tsutomu Chou, Shinji Hara, Kosuke Tanaka, Ryo Hosoi
  • Publication number: 20130250742
    Abstract: The thermally-assisted magnetic recording head includes: a laser light source having an emission surface, the emission surface allowing laser light to be emitted therefrom; a waveguide having a core and a cladding, the core allowing the laser light emitted from the laser light source to propagate therethrough, and the cladding surrounding the core; a magnetic pole; and a plasmon generator. Each of the core and the cladding has an end surface facing the emission surface, and the end surface of the cladding suppresses returning of the laser light to the laser light source.
    Type: Application
    Filed: March 21, 2012
    Publication date: September 26, 2013
    Applicants: SAE MAGNETICS (H.K.) LTD., TDK CORPORATION
    Inventors: Eiji KOMURA, Tsutomu CHOU, Koji SHIMAZAWA, Shinji HARA, Ryo HOSOI, Nobuyuki MORI, Yasutoshi FUJITA, Hideki TANZAWA
  • Patent number: 8537645
    Abstract: A near-field light generating element includes a plasmon generator, and the plasmon generator has a base plate and a protrusion. The protrusion protrudes from one side of the base plate, wherein when H represents a height direction of the protrusion from the one side and W represents a width direction perpendicular to the height direction (H), a section taken along a W-H plane is of a rectangular shape whose opposite corners in the height direction (H) are rounded.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: September 17, 2013
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Koji Shimazawa, Shinji Hara, Eiji Komura, Ryo Hosoi
  • Publication number: 20130215725
    Abstract: The present invention provides a thermally assisted magnetic head with improved recording performance. The thermally assisted magnetic head includes a recording element and a near-field light generating element. The recording element includes a main pole appearing on a medium-facing surface, and a bit inversion starting region intended to be a maximum recording magnetic field generating position is formed at a leading edge of the main pole. The near-field light generating element is located on a leading side of the main pole and capable of creating a heating spot due to a near-field light on a near-field light generating end face appearing on the medium-facing surface. The bit inversion starting region is located within one-half of a diameter of the heating spot from a center of the heating spot.
    Type: Application
    Filed: February 22, 2012
    Publication date: August 22, 2013
    Applicant: TDK CORPORATION
    Inventors: Kei HIRATA, Kosuke Takana, Tsutomu Chou, Susumu Aoki, Makoto Isogai, Tetsuya Roppongi
  • Patent number: 8498083
    Abstract: A magneto-resistive effect (MR) element includes first and second magnetic layers where a relative angle formed by magnetization directions changes in response to an external magnetic field and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The first magnetic layer is positioned closer to a substrate above which the MR element is formed than the second magnetic layer. The spacer layer includes a main spacer layer that is composed of gallium oxide as a primary component and a bottom layer that is positioned between the main spacer layer and the first magnetic layer and that is composed of partially oxidized copper as a primary component.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: July 30, 2013
    Assignee: TDK Corporation
    Inventors: Hayato Koike, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
  • Patent number: 8477461
    Abstract: A thin film magnetic head including an MR laminated body composed of a first and second MR magnetic layers, first and second shield layers, and a bias magnetic field application layer provided on an opposite side of an air bearing surface (ABS) of the MR laminated body in order to apply a bias magnetic field orthogonal relative to the ABS. The first shield layer includes a first exchange coupling magnetic field application layer and a first antiferromagnetic layer; and the second shield layer includes a second exchange coupling magnetic field application layer and a second antiferromagnetic layer.
    Type: Grant
    Filed: July 29, 2008
    Date of Patent: July 2, 2013
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Yoshihiro Tsuchiya, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
  • Patent number: 8462593
    Abstract: A magnetic head includes a dielectric waveguide to propagate propagation light; a metal waveguide facing the dielectric waveguide, coupling to the propagation light propagating through the dielectric waveguide in a surface plasmon mode, generating first surface plasmon with larger wavenumber than that of the propagation light, and propagating the first surface plasmon; a near-field light generating element facing the metal waveguide and extending to ABS, coupling to the first surface plasmon propagating on the metal waveguide in a surface plasmon mode, generating second surface plasmon with wavenumber larger than that of the first surface plasmon, propagating the second surface plasmon to an end part on the ABS side, and generating near-field light at the end part on the ABS side; and a recording magnetic pole provided in the vicinity of the near-field light generating element and having an end part positioned on the ABS.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: June 11, 2013
    Assignee: TDK Corporation
    Inventors: Eiji Komura, Koji Shimazawa, Tsutomu Chou, Shinji Hara, Kosuke Tanaka
  • Patent number: 8441763
    Abstract: A magneto-resistive effect (MR) element includes first and second magnetic layers in which a relative angle formed by magnetization directions changes in response to an external magnetic field, and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer, on an air bearing surface, has a larger film thickness at both side edge parts in a track width direction than a film thickness at a central part in a track width direction. When a region of the spacer layer on the air bearing surface is divided into quarters which are both side edge part regions and two central regions such that track width direction lengths are equivalent, an average film thickness of a region where the both side edge regions are combined is preferably larger than a region where the two central regions are combined.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: May 14, 2013
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa, Hayato Koike
  • Patent number: 8437237
    Abstract: A light source unit includes a light source and a photodetector. The light source has an emission part for emitting light. The photodetector has a light receiving surface for receiving the light emitted from the emission part, and detects the light. The light source unit further includes a grating made of metal and disposed to extend along the light receiving surface. The grating includes a plurality of line-shaped portions that each extend in a direction intersecting the direction of travel of the light and that are located at positions different from each other along the direction of travel of the light.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: May 7, 2013
    Assignee: TDK Corporation
    Inventors: Eiji Komura, Tsutomu Chou, Koji Shimazawa
  • Patent number: 8432645
    Abstract: An MR element includes a stack, being a pillar or trapezoidal stack, including first and second magnetic layers in which a relative angle formed by magnetization directions changes according to an external magnetic field, and a spacer layer that is positioned between the first magnetic layer and the second magnetic layer, and that is provided with a main spacer layer that is composed of gallium oxide, zinc oxide or magnesium oxide as a primary component, wherein, one part of side surfaces of the stack forms a part of an air bearing surface; and a cover layer that covers at least another part of the side surfaces of the stack and that is composed of gallium oxide as a primary component.
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: April 30, 2013
    Assignee: TDK Corporation
    Inventors: Hironobu Matsuzawa, Yoshihiro Tsuchiya, Hayato Koike, Tsutomu Chou
  • Patent number: 8427927
    Abstract: The thermally-assisted magnetic recording head includes: a magnetic pole; a waveguide allowing a transverse-electric (TE) wave oscillating in a cross-track direction to propagate toward an air bearing surface; and a plasmon generator having a tip portion near the air bearing surface, the tip portion being provided to overlap, in a down-track direction, with both the magnetic pole and the waveguide, and having a quadrangular cross-section substantially parallel to the air bearing surface.
    Type: Grant
    Filed: February 10, 2012
    Date of Patent: April 23, 2013
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Koji Shimazawa, Shinji Hara, Eiji Komura, Ryo Hosoi
  • Patent number: 8405935
    Abstract: A magnetoresistive effect element (MR element) includes first and second magnetic layers of which relative angles formed by magnetization directions change in relation to an external magnetic field; and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The first magnetic layer is positioned on a side closer than the second magnetic layer in regards to a substrate above which the magnetoresistive effect element is formed, and the spacer layer includes a main spacer layer made of gallium oxide as the primary component, and a first nonmagnetic layer positioned between the main spacer layer and the first magnetic layer and contains copper and gallium.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: March 26, 2013
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa, Hayato Koike
  • Patent number: 8400886
    Abstract: A thermally-assisted magnetic recording head that includes a pole that generates a writing magnetic field, a waveguide through which light propagates, a plasmon generator that surface-evanescent-couples with the light propagating through the waveguide, wherein the plasmon generator includes a portion where a cross-sectional area gradually decreases as going toward a depth side from an air bearing surface when being observed from a cross section parallel to the air bearing surface. The volume of the plasmon generator can be decreased and an exposed area of a front surface on the air bearing surface can be increased. When a thermal expansion from the temperature increase occurs in the plasmon generator, a rate that the plasmon generator projects from the air bearing surface is suppressed to extremely low levels. Accordingly, a chronological degradation of output can be suppressed and thermally-assisted recording having a high and long-term reliability is achieved.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: March 19, 2013
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Tsutomu Chou, Eiji Komura
  • Patent number: 8400885
    Abstract: A thermally-assisted magnetic recording head includes: a pole that generates a writing magnetic field from an end surface that forms a part of an air bearing surface that opposes a magnetic recording medium; a waveguide that propagates light to excite surface plasmon; and a plasmon generator that is provided between the pole and the waveguide and that generates near-field light from a near-field light generating end surface that forms a part of the air bearing surface by coupling with the light in a surface plasmon mode. The plasmon generator includes a flat plate part and a projection part that projects from the flat plate part to the waveguide side and is provided closer to a trailing side than the pole is.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: March 19, 2013
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Tetsuya Roppongi, Kosuke Tanaka, Tsutomu Chou, Eiji Komura