Patents by Inventor Kouichi Tsuda

Kouichi Tsuda 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: 8652317
    Abstract: An alumina nanohole array and a method of fabricating the same includes the steps of forming an aluminum thin-film on a substrate at a substrate temperature of ?80° C. or below so that crystal grain growth is suppressed, even when a high-purity aluminum material is used, thus providing improved surface smoothness; and anodizing the aluminum thin-film. Preferably, the method additionally includes texturing by pressing a mold having an orderly array of projections against the aluminum thin-film to form pits on the aluminum thin-film which enables a larger array area to be formed. When the mold and the aluminum thin-film are held at a temperature of 150 to 200° C., the pressure used for pit formation is reduced. A magnetic recording medium manufactured by a method therefore includes forming a magnetic layer within the nanoholes so that the medium is suitable as a bit patterned media for a perpendicular recording system.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: February 18, 2014
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Kouichi Tsuda
  • Patent number: 8206778
    Abstract: A method of manufacturing a magnetic recording medium includes the steps of forming an intermediate layer that is electrically conductive over a non-magnetic substrate; forming an aluminum-containing layer on the intermediate layer; forming a plurality of micro pits in the aluminum-containing layer; generating an alumina-containing layer by anode oxidation of the aluminum-containing layer and simultaneously forming a plurality of nano holes in the alumina-containing layer originating from the plurality of micro pits respectively to expose the intermediate layer; cleaning and drying the plurality of nano holes using a fluid selected from the group consisting of a sub- and super-critical carbon dioxide fluid; and depositing a magnetic metal selectively through the plurality of nano holes on the intermediate layer to form a plurality of magnetic recording elements that collectively form a magnetic recording layer.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: June 26, 2012
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventor: Kouichi Tsuda
  • Patent number: 8124257
    Abstract: A substrate for a recording medium suited for thermally assisted recording methods has a disc shape with a center hole and includes a silicon single-crystal supporting member; an SiO2 film formed on the silicon single-crystal supporting member; a main face having a film thickness of the SiO2 film thereon which is less than 10 nm; a substrate inner periphery end face adjacent to the center hole; a substrate inner periphery chamfer portion adjacent to the main face and to the substrate inner periphery end face; a substrate outer periphery end face positioned on the side of the main face opposite the substrate inner periphery end face; and a substrate outer periphery chamfer portion adjacent to the main face and to the substrate outer periphery end face. A magnetic recording medium includes at least the above substrate and a magnetic recording layer formed on the substrate.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: February 28, 2012
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Kouichi Tsuda
  • Publication number: 20100195249
    Abstract: A method of manufacturing a magnetic recording medium includes forming an electrically conductive intermediate layer over a non-magnetic substrate; forming an aluminum-containing layer on the intermediate layer; forming a plurality of micro pits in the aluminum-containing layer; generating an alumina-containing layer by oxidizing the aluminum-containing layer and simultaneously forming nano holes in the alumina-containing layer originating from the micro pits to expose the intermediate layer; cleaning and drying the nano holes using a sub- and super-critical fluid; and depositing a magnetic metal selectively on the intermediate layer to form a magnetic recording layer having a plurality of magnetic recording elements. The method thus employs alumina nano holes (ANHs) to fill magnetic metal uniformly and selectively even for ANHs with a diameter not larger than 25 nm.
    Type: Application
    Filed: February 3, 2010
    Publication date: August 5, 2010
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventor: Kouichi Tsuda
  • Publication number: 20090148723
    Abstract: A substrate for a recording medium suited for thermally assisted recording methods has a disc shape with a center hole and includes a silicon single-crystal supporting member; an SiO2 film formed on the silicon single-crystal supporting member; a main face having a film thickness of the SiO2 film thereon which is less than 10 nm; a substrate inner periphery end face adjacent to the center hole; a substrate inner periphery chamfer portion adjacent to the main face and to the substrate inner periphery end face; a substrate outer periphery end face positioned on the side of the main face opposite the substrate inner periphery end face; and a substrate outer periphery chamfer portion adjacent to the main face and to the substrate outer periphery end face. A magnetic recording medium includes at least the above substrate and a magnetic recording layer formed on the substrate.
    Type: Application
    Filed: December 8, 2008
    Publication date: June 11, 2009
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventor: Kouichi TSUDA
  • Publication number: 20090145769
    Abstract: An alumina nanohole array and a method of fabricating the same includes the steps of forming an aluminum thin-film on a substrate at a substrate temperature of ?80° C. or below so that crystal grain growth is suppressed, even when a high-purity aluminum material is used, thus providing improved surface smoothness; and anodizing the aluminum thin-film. Preferably, the method additionally includes texturing by pressing a mold having an orderly array of projections against the aluminum thin-film to form pits on the aluminum thin-film which enables a larger array area to be formed. When the mold and the aluminum thin-film are held at a temperature of 150 to 200° C., the pressure used for pit formation is reduced. A magnetic recording medium manufactured by a method therefore includes forming a magnetic layer within the nanoholes so that the medium is suitable as a bit patterned media for a perpendicular recording system.
    Type: Application
    Filed: December 2, 2008
    Publication date: June 11, 2009
    Applicant: Fuji Electric Device Technology Co., Ltd
    Inventor: Kouichi TSUDA
  • Publication number: 20080213626
    Abstract: A method of manufacture of a glass substrate for a magnetic recording medium, which has both high substrate strength and low alkaline elution, includes an etching process of etching the inner-edge face of a donut-shaped glass substrate having an aluminosilicate composition, formed by removing the center portion of a die-molded disc-shaped glass substrate, and an alkali sealing process of performing alkali sealing treatment by proton substitution of alkali ions in the surface layer of the etched donut-shaped glass substrate. The process is used to manufacture a magnetic recording medium incorporating a glass substrate having a total alkaline elution amount of less than 3.1 ?g/disk, wherein the magnetic recording medium has a transverse rupture strength greater than 132 N.
    Type: Application
    Filed: January 9, 2008
    Publication date: September 4, 2008
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Ryoji KOBAYASHI, Youichi TEI, Kouichi TSUDA
  • Publication number: 20070264533
    Abstract: Information recording medium glass substrate which is a molded article composed of an alkali metal-containing glass material having a composition including at least B, Al, alkali metals, Zn, and Si, and satisfying certain relational equations in molar proportions in terms of oxides thereof, has a low molding temperature, excellent durability, and a reduced number of surface defects. An information recording medium having such a glass substrate and a magnetic layer formed thereon has excellent low-temperature workability and excellent weathering resistance. The glass substrate is suitable for perpendicular magnetic recording because the glass composition suppresses alkali elution from the glass substrate and the glass substrate has substantially no surface-attached foreign matter having a height of about 10 nm or less and having SiO2 as a main component thereof.
    Type: Application
    Filed: May 14, 2007
    Publication date: November 15, 2007
    Applicant: Fuji Electric Device Technology Co., Ltd
    Inventors: Kouichi Tsuda, Ryoji Kobayashi
  • Patent number: 6939595
    Abstract: An injection molded thermoplastic magnetic recording substrate a medium formed therewith, and a method thereof is composed of a thermoplastic or allyloxymethylstyrene type resin.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: September 6, 2005
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Youichi Tei, Kouichi Tsuda, Ryoji Kobayashi, Syoji Sakaguchi
  • Publication number: 20040151948
    Abstract: An injection molded thermoplastic magnetic recording substrate a medium formed therewith, and a method thereof is composed of a thermoplastic or allyloxymethylstyrene type resin.
    Type: Application
    Filed: November 13, 2003
    Publication date: August 5, 2004
    Inventors: Youichi Tei, Kouichi Tsuda, Ryoji Kobayashi, Syoji Sakaguchi