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.

Date of Patent:
Sep. 13, 2005

Filed:

Sep. 15, 2003
Applicant:

Toru Yokohata, Kawasaki, JP;

Inventor:

Toru Yokohata, Kawasaki, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B005/02 ;
U.S. Cl.
CPC ...
Abstract

An acoustic emission sensor is mounted on a flying slider opposed to a rotating recording medium, for example. The acoustic emission sensor outputs a detection signal in response to the sound of collision. When a protrusion exists on the recording medium, the flying slider is expected to collide against the protrusion at a predetermined fixed angular position. A variation is induced in the detection signal based on the collision between the flying slider and the protrusion in synchronization with the rotation of the recording medium. Specifically, when a variation is synchronized with the angular position signal of the recording medium, the variation should correspond to a protrusion existing on the surface of the recording medium. If the component corresponding to the variation is extracted out of the detection signal, a protrusion on the recording medium can be determined at a higher accuracy.


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