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. 08, 2013
Filed:
Feb. 27, 2009
Applicants:
Yuji Horie, Tokyo, JP;
Tatsuya Tanifuji, Tokyo, JP;
Noriyuki Kumasaka, Tokyo, JP;
Inventors:
Assignee:
Nihon Micro Coating Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
B24B 7/22 (2006.01);
U.S. Cl.
CPC ...
Abstract
A glass substrate for perpendicular magnetic recording, having a surface with an average surface roughness of 2.0Å or less and surface height variations of 1Å or less with wavelengths in the range of 0.05 mm-0.5 mm in both radial and circumferential directions, is produced by rotating a glass substrate, supplying polishing slurry containing a specified amount of abrading particles of artificial diamond on its surface, pressing a polishing tape on the surface and causing this polishing tape to travel in a direction opposite to the direction of rotation of the glass substrate.