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:
Mar. 04, 2014
Filed:
Jun. 22, 2010
Chiyo Saito, Tokyo, JP;
Chiyo Saito, Tokyo, JP;
WD Media (Singapore) Pte. Ltd., Singapore, SG;
Abstract
A characteristic evaluation method of a perpendicular magnetic recording medium suitable for obtaining a perpendicular magnetic recording medium which can respond to much higher recording density is provided. This is an evaluation method of a perpendicular magnetic recording medium, including a process of recording a first signal of a specific frequency at an arbitrary first position in the perpendicular magnetic recording medium; a process of measuring a reproduction output of the first signal and of measuring a signal/noise ratio (initial value) of the first signal at a peak position where the reproduction output becomes the maximum; a process of recording a signal of a specific frequency at a second position away from the first position by a predetermined distance in the radial direction of the perpendicular magnetic recording medium; a process of measuring the signal/noise ratio of the first signal at the peak position again; a process of repeating the process of recording the signal of the specific frequency at a position brought close to the first position from the second position by a predetermined distance and of measuring the signal/noise ratio of the first signal at the peak position again while sequentially getting closer to the first position from the second position; and a process of determining whether the value of the signal/noise ratio has lowered from the initial value by a predetermined range or more.