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:
Oct. 22, 2013
Filed:
Sep. 28, 2012
Applicant:
Hoya Corporation, Tokyo, JP;
Inventors:
Tomoyuki Yamaguchi, Tokyo, JP;
Kyosuke Iiizumi, Tokyo, JP;
Assignee:
Hoya Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B05D 5/12 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method of manufacturing a magnetic disk glass substrate has a cleaning step of cleaning the glass substrate. In the cleaning step, the cleaning is performed under an acidic condition using a cleaning liquid containing oxalate ions and bivalent iron ions. In parallel with the cleaning step or before or after the cleaning step, trivalent iron ions generated by oxidation of the bivalent iron ions contained in the cleaning liquid are reduced by ultraviolet irradiation.