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:
Sep. 15, 2009
Filed:
Mar. 12, 2007
Tsuyoshi Yoshizawa, Nagano, JP;
Tsuyoshi Yoshizawa, Nagano, JP;
Fuji Electric Device Technology Co., Ltd., Tokyo, JP;
Abstract
To measure the nonlinear distortion of a magnetic disk even at a high recording density, a nonlinear transition shift and a partial erasure are separately measured. A periodic pattern containing dibits and isolated bits, and a periodic pattern consisting only of isolated bits, are written and read in synchronism with the rotations of the magnetic disk. The reproduced waveforms of the respective periodic patterns are frequency-analyzed in a state where the phases of the periodic patterns are in agreement, thereby to obtain odd-numbered order harmonic components. The partial erasure and the nonlinear transition shift are evaluated on the basis of the ratio between the odd-numbered order harmonic components.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile