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. 01, 1992
Filed:
Nov. 30, 1990
Jonathan D Coker, Rochester, MN (US);
Richard L Galbraith, Rochester, MN (US);
Paul P Howard, Rochester, MN (US);
Gregory J Kerwin, Rochester, MN (US);
Gordon J Smith, Rochester, MN (US);
IBM Corporation, Armonk, NY (US);
Abstract
A method and apparatus are provided for measuring flying height changes of a transducer head relative to a disk surface of a rotating disk in a disk file. A predetermined pattern is written on at least one predetermined region of the disk file. The predetermined region is normally not rewritten during operation of the disk file. At least one readback signal is sensed from at least one predetermined region of the disk surface. A plurality of sample values are identified corresponding to each readback signal. A change in the flying height is calculated utilizing the identified sample values. A frequency equalization number K can be utilized to calculate the magnitude and sign of the flying height change. Alternatively, real-time digital analysis of a predetermined pattern written on at least one predetermined region of the disk surface can be utilized to calculate the magnitude and sign of the flying height change.