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. 13, 2005
Filed:
Oct. 11, 2001
Julian Lewkowicz, Lafayette, CO (US);
Larry J. Koudele, Broomfield, CO (US);
Julian Lewkowicz, Lafayette, CO (US);
Larry J. Koudele, Broomfield, CO (US);
Maxtor Corporation, Longmont, CO (US);
Abstract
A method and apparatus for detecting a high fly write condition in a disk drive is disclosed. Amplitudes of automatic gain control (AGC) fields are used in connection with determining whether a high fly write condition exists in a disk drive, since the amplitude of an AGC field read by a head is generally related to the flying height of the head. In one embodiment, a calibration process is performed to obtain average amplitudes of AGC fields on a zone-by-zone basis for a head associated with a disk surface. These average amplitudes of AGC fields are then stored onto the disk surface for later use. When a write operation is to be performed, the head measures the amplitude of the AGC field associated with a data sector onto which a block of data is to be stored. The measured amplitude of the AGC field is compared to the average amplitude of the AGC fields for the zone associated with the AGC field being read. If the difference between the measured amplitude of the AGC field and the average amplitude for the AGC fields for the zone is outside of a certain tolerance, a high fly write condition may exist. Accordingly, data written during a high fly write condition may be rewritten when the flying height has returned to normal or some other remedial action may be taken.