Patents by Inventor Reijiro Maruyama

Reijiro Maruyama 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 of using aluminum alloy as substrate for magnetic discs with enhanced magnetic recording density
    Patent number: 4826737
    Abstract: A substrate for a magnetic disc prepared from an aluminum alloy which consists essentially of from 3.0 to 5.0 percent, preferably from 3.5 to 4.5 percent, Mg, from 0.5 to 3.0 percent, preferably from 0.5 to 1.7 percent, Zn, and the balance Al and inevitable impurities. The inevitable impurities contain not more than 0.10 percent Si, not more than 0.10 percent Fe, not more than 0.01 percent, Mn, not more than 0.01 percent Cr, not more than 0.01 percent Ni, and not more than 0.01 percent Ti.The aluminum alloy substrate may also contain from 0.3 to 2.0 percent, preferably from 0.5 to 1.0 percent, Cu, and/or from 0.02 to 0.5 percent, preferably from 0.05 to 0.2 percent, Zr.
    Type: Grant
    Filed: July 7, 1986
    Date of Patent: May 2, 1989
    Assignee: Mitsubishi Aluminum Kabushiki Kaisha
    Inventors: Kazuo Yamada, Masahiro Tsuchiya, Hideaki Kakita, Reijiro Maruyama, Yoshinobu Okada, Yo Takeuchi