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.:

US 8169868 B1

PDF
Full Text
Expired
Date of Patent:
May. 01, 2012

Filed:

Mar. 02, 2010
Applicant:

Ayumu Ishihara, Kamisato, JP;

Inventor:

Ayumu Ishihara, Kamisato, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 20/18 (2006.01);
U.S. Cl.
CPC ...
Abstract

An optical defect detection method for patterned media includes: irradiating a laser beam onto a patterned medium and obtaining reflected light by reflection very close to a sample; outputting the reflected light as an analog electrical signal from an optical receiver; converting the analog signal to a digital signal; obtaining a surface profile in a track direction by sampling the analog signal; obtaining a servo area profile by setting a slice for detecting servo area; calculating an average value in a track width direction based on plural servo area profiles; generating a master servo area profile based on the average value; obtaining a difference between the master servo area profile and the specific servo area profile; and detecting the presence of a defect including surface roughness, process fluctuation, and adhesion of foreign matters, from a differential waveform.


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Ishihara, Ayumu. (2012). Method for detecting surface defects in patterned media (U.S. Patent No. 8169868). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/8169868

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