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:
Dec. 23, 2008
Filed:
Dec. 22, 2006
Satoshi Yamashita, Kawasaki, JP;
Syunji Saitou, Kawasaki, JP;
Yukio Abe, Kawasaki, JP;
Shigenori Yanagi, Kawasaki, JP;
Satoshi Yamashita, Kawasaki, JP;
Syunji Saitou, Kawasaki, JP;
Yukio Abe, Kawasaki, JP;
Shigenori Yanagi, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An amplitude measurement unit measures an amplitude of a read signal from a preamble unit in a servo area of a predetermined frame number m per one rotation of the recording medium for a predetermined cycle number n while increasing an electric power amount distributed to the heater in the state in which the head is positioned to a track on the recording medium, and a mean amplitude calculating unit calculates a mean amplitude from an amplitude measurement value which is measured by the number which is the frame number m multiplied by the cycle number n. A contact determination unit calculates a mean amplitude variation amount per a unit heater electric power amount as a contact determination value, and determines that the head is in contact with the recording medium when the contact determination value is lower than a predetermined threshold value, and a flying height calculating unit which calculates a flying height of the head with respect to the surface of the recording medium from the heater electric power amount at the point when contact is determined.