The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 2015
Filed:
Sep. 13, 2011
Applicants:
Hazuki Nakae, Kyoto, JP;
Toshiharu Mori, Osaka, JP;
Inventors:
Hazuki Nakae, Kyoto, JP;
Toshiharu Mori, Osaka, JP;
Assignee:
Hoya Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 5/00 (2006.01); G11B 5/84 (2006.01); C03C 19/00 (2006.01); C03C 21/00 (2006.01);
U.S. Cl.
CPC ...
G11B 5/8404 (2013.01); C03C 19/00 (2013.01); C03C 21/002 (2013.01);
Abstract
For an information storage medium a glass substrate is produced in a method including the steps of: polishing a glass substrate with a polishing agent applied thereon; and subsequently, chemically strengthening a major surface of the glass substrate. The polishing agent contains cerium oxide at a purity equal to or larger than 99% by mass for CeO/TREO, and has an alkaline earth metal content having a total mass equal to or smaller than 10 ppm by mass. The step of polishing is performed with a soft polishing pad to polish the glass substrate.