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:
Mar. 03, 2015
Filed:
Mar. 10, 2011
Applicant:
Hazuki Nakae, Kyoto, JP;
Inventor:
Hazuki Nakae, Kyoto, JP;
Assignee:
Hoya Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B24B 7/00 (2006.01); C03C 3/04 (2006.01); B24B 37/04 (2012.01); G11B 5/84 (2006.01); C03C 3/095 (2006.01); C08C 19/00 (2006.01); G11B 5/73 (2006.01);
U.S. Cl.
CPC ...
G11B 5/8404 (2013.01); C03C 3/095 (2013.01); C08C 19/00 (2013.01); G11B 5/7315 (2013.01);
Abstract
Disclosed is a method of producing a glass substrate for an information recording medium including a rough polishing step of performing a rough polishing on a glass material containing 0.01 to 2 mass % of cerium oxide; a washing step of washing the glass material after the rough polishing step, so that the cerium content of the glass material surface becomes 0.125 ng/cmor less; and a precision polishing step of performing precision polishing on the glass material after the washing step by cyclically using a polishing material containing colloidal silica.