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:
Nov. 28, 2023
Filed:
Oct. 31, 2019
Sony Group Corporation, Tokyo, JP;
Masaru Terakawa, Tokyo, JP;
Minoru Yamaga, Tokyo, JP;
Sony Group Corporation, Tokyo, JP;
Abstract
Provided is a magnetic recording medium capable of implementing higher-density recording. This magnetic recording medium includes a substrate containing a polyester and a magnetic layer disposed on the substrate, including a plurality of types of magnetic powder. A surface of the magnetic layer has an arithmetic average roughness Ra of 2.5 nm or less. PSD to a spatial wavelength of 5 μm is 2.5 μm or less. The magnetic layer has an average thickness of 90 nm or less. The magnetic powder has an average aspect ratio of 1.0 or more and 3.0 or less. A coercive force in a perpendicular direction is 3000 oersted or less. A ratio of a coercive force in a longitudinal direction to the coercive force in the perpendicular direction is 0.8 or less. A half-value width of an isolated waveform in a reproduced waveform of a data signal is 200 nm or less.