Patents by Inventor Junji Masunaga

Junji Masunaga 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).

  • Method for the production of glass substrates for magnetic recording mediums
    Patent number: 6530825
    Abstract: A method for the production of a glass substrate for magnetic recording mediums comprises the steps of sandwiching an abrasion board for correction between upper and lower surface tables of a both side-polishing device for polishing the glass substrate, while these upper and lower surface tables are fitted to the polishing device, rotating the upper and lower surface tables in the opposite directions while supplying cooling water to thus polish the surface of these tables to a flatness of the table surface on the order of not more than 30 &mgr;m; then adhering abrasion cloths to the upper and lower surface tables, respectively; thereafter repeatedly polishing the surface of the glass substrate for magnetic recording mediums. The production method permits the efficient production of an excellent glass substrate for magnetic recording mediums.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: March 11, 2003
    Assignee: Mitsui Mining And Smelting Co., Ltd.
    Inventors: Akio Fujimura, Toshio Hosaka, Junji Masunaga
  • Method for the production of glass substrates for magnetic recording mediums
    Publication number: 20020013121
    Abstract: A method for the production of a glass substrate for magnetic recording mediums comprises the steps of sandwiching an abrasion board for correction between upper and lower surface tables of a both side-polishing device for polishing the glass substrate, while these upper and lower surface tables are fitted to the polishing device, rotating the upper and lower surface tables in the opposite directions while supplying cooling water to thus polish the surface of these tables to a flatness of the table surface on the order of not more than 30 &mgr;m; then adhering abrasion cloths to the upper and lower surface tables, respectively; thereafter repeatedly polishing the surface of the glass substrate for magnetic recording mediums. The production method permits the efficient production of an excellent glass substrate for magnetic recording mediums.
    Type: Application
    Filed: June 11, 2001
    Publication date: January 31, 2002
    Inventors: Akio Fujimura, Toshio Hosaka, Junji Masunaga