Patents by Inventor Yasunari Hirano

Yasunari Hirano 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).

  • Manufacturing method of a glass substrate for a magnetic disk
    Patent number: 8969277
    Abstract: An object of the invention is to remove effectively metallic contaminants adhering to the glass substrate surfaces without increasing roughness of the glass substrate surfaces in the glass substrate for a magnetic disk. In a manufacturing method of a glass substrate for a magnetic disk having a cleaning step of the glass substrate, the cleaning step comprising a cleaning treatment of contacting the glass substrate with an alkaline aqueous solution having a gluconate in concentration of not less than 0.05 wt % and not more than 2 wt % added thereto and a pH of not less than 9 and not more than 11 is appended.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: March 3, 2015
    Assignee: Hoya Corporation
    Inventors: Takuhiro Hirakawa, Yasunari Hirano, Kouichi Tamoto, Tomoyuki Yamaguchi
  • Manufacturing method of a glass substrate for a magnetic disk
    Patent number: 8926759
    Abstract: An object of the invention is to remove effectively metallic contaminants adhering to the glass substrate surfaces without increasing roughness of the glass substrate surfaces in the glass substrate for a magnetic disk. In a manufacturing method of a glass substrate for a magnetic disk, a cleaning step comprising a treatment of contacting the glass substrate with a cleaning liquid containing peroxodisulfate and having a pH of not less than 2 and not more than 4 is appended. In addition, an example of the cleaning liquid can be prepared by adding sodium peroxodisulfate to an acidic solution.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: January 6, 2015
    Assignee: Hoya Corporation
    Inventors: Takuhiro Hirakawa, Yasunari Hirano, Kouichi Tamoto, Tomoyuki Yamaguchi
  • MANUFACTURING METHOD OF A GLASS SUBSTRATE FOR A MAGNETIC DISK
    Publication number: 20130008463
    Abstract: An object of the invention is to remove effectively metallic contaminants adhering to the glass substrate surfaces without increasing roughness of the glass substrate surfaces in the glass substrate for a magnetic disk. In a manufacturing method of a glass substrate for a magnetic disk, a cleaning step comprising a treatment of contacting the glass substrate with a cleaning liquid containing peroxodisulfate and having a pH of not less than 2 and not more than 4 is appended. In addition, an example of the cleaning liquid can be prepared by adding sodium peroxodisulfate to an acidic solution.
    Type: Application
    Filed: March 31, 2011
    Publication date: January 10, 2013
    Applicant: HOYA CORPORATION
    Inventors: Takuhiro Hirakawa, Yasunari Hirano, Kouichi Tamoto, Tomoyuki Yamaguchi
  • MANUFACTURING METHOD OF A GLASS SUBSTRATE FOR A MAGNETIC DISK
    Publication number: 20130012104
    Abstract: The present invention has an object to remove effectively metallic contaminants adhering to the glass substrate surfaces without increasing roughness of the glass substrate surfaces in the glass substrate for a magnetic disk. In a manufacturing method of a glass substrate for a magnetic disk having a cleaning step of the glass substrate, cleaning step having a treatment of contacting the glass substrate with a cleaning liquid containing oxalate and divalent iron ions and having a pH of not less than 2 and not more than 4. The divalent iron ions are added by adding ammonium iron (II) sulfate, iron (II) sulfate and iron oxalate (II) to oxalic acid.
    Type: Application
    Filed: March 31, 2011
    Publication date: January 10, 2013
    Applicant: HOYA CORPORATION
    Inventors: Tomoyuki Yamaguchi, Yasunari Hirano, Takuhiro Hirakawa
  • MANUFACTURING METHOD OF A GLASS SUBSTRATE FOR A MAGNETIC DISK
    Publication number: 20120190606
    Abstract: An object of the invention is to remove effectively metallic contaminants adhering to the glass substrate surfaces without increasing roughness of the glass substrate surfaces in the glass substrate for a magnetic disk. In a manufacturing method of a glass substrate for a magnetic disk having a cleaning step of the glass substrate, the cleaning step comprising a cleaning treatment of contacting the glass substrate with an alkaline aqueous solution having a gluconate in concentration of not less than 0.05 wt % and not more than 2 wt % added thereto and a pH of not less than 9 and not more than 11 is appended.
    Type: Application
    Filed: March 31, 2011
    Publication date: July 26, 2012
    Applicant: HOYA CORPORATION
    Inventors: Takuhiro Hirakawa, Yasunari Hirano, Kouichi Tamoto, Tomoyuki Yamaguchi