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:
Aug. 17, 2021
Filed:
Apr. 26, 2019
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 5/82 (2006.01); G11B 5/84 (2006.01); G11B 5/73 (2006.01); B82Y 10/00 (2011.01); B82Y 40/00 (2011.01);
U.S. Cl.
CPC ...
G11B 5/82 (2013.01); G11B 5/73913 (2019.05); G11B 5/73919 (2019.05); G11B 5/73921 (2019.05); 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 an arithmetic average roughness Ra of each of the main surfaces is 0.11 nm or less. The arithmetic average roughness Ra is a value obtained through measurement using an atomic force microscope provided with a probe having a probe tip provided with a carbon nanofiber rod-shaped member. The magnetic-disk substrate is made of glass or aluminum alloy.