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. 24, 2023
Filed:
Apr. 24, 2018
Applicant:
Sony Corporation, Tokyo, JP;
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/667 (2006.01); G11B 5/73 (2006.01); G11B 5/706 (2006.01); G11B 5/712 (2006.01); G11B 5/65 (2006.01); H01F 1/147 (2006.01);
U.S. Cl.
CPC ...
G11B 5/667 (2013.01); G11B 5/653 (2013.01); G11B 5/70642 (2013.01); G11B 5/712 (2013.01); G11B 5/73919 (2019.05); H01F 1/147 (2013.01);
Abstract
Provided is a magnetic recording medium having a recording track width of 2 μm or less, including: a recording layer containing a powder of particles containing ε iron oxide, in which a squareness ratio measured in a transport direction is 30% or less, a squareness ratio S1 measured in the transport direction and a squareness ratio S2 measured in a width direction satisfy a relationship S1≥S2, a coercive force is 220 kA/m or greater and 310 kA/m or less, an activation volume is 8000 nmor less, and in a switching field distribution (SFD) curve, a peak ratio X/Y of a main peak height X and a height Y of a sub-peak near zero magnetic field is 3.0 or greater.