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:
Jun. 11, 2019
Filed:
Mar. 31, 2016
Applicant:
Hoya Corporation, Tokyo, JP;
Inventors:
Masanobu Itaya, Minami-Alps, JP;
Kinobu Osakabe, Tokorozawa, JP;
Assignee:
HOYA CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/73 (2006.01); G11B 5/82 (2006.01); G11B 5/84 (2006.01); B82Y 10/00 (2011.01); B82Y 40/00 (2011.01);
U.S. Cl.
CPC ...
G11B 5/82 (2013.01); G11B 5/7315 (2013.01); G11B 5/84 (2013.01); G11B 5/8404 (2013.01); B82Y 10/00 (2013.01); B82Y 40/00 (2013.01);
Abstract
A magnetic-disk substrate has a pair of main surfaces and arithmetic average roughnesses Ra of the main surfaces are each 0.11 nm or less. Also, in surface unevenness of the main surfaces, an average area of regions occupied by a plurality of protrusions having a height of 0.1 nm or more from an average plane of the surface unevenness is 25 nm/protrusion or less. The arithmetic average roughness Ra and the surface unevenness are measured using an atomic force microscope with a probe having a probe tip provided with a carbon nanofiber rod-shaped member.