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:
Aug. 04, 1992
Filed:
Mar. 30, 1990
Michael D Sidman, Colorado Springs, CO (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A disk drive wherein the radial position and velocity of a sensing head being positioned by a servo system is estimated from the sensing of servo signals arranged in successive groups of tracks on a disk surface, each of the tracks in a group being of a different track type and said servo signals being in relative circumferential positions acording to the track types of the tracks containing those signals. The sensed servo signals are linearly related to the radial position of the head relative to the track containing the corresponding servo signal, the linear relationship extending over a radial distance of a plurality of tracks. The position is ascertained as a Gray code representation of the track type over which the sensor is positioned, wherein the first bit of the Gray code depends on whether the sum of the sensed amplitudes of a first pair of servo signals is greater or less than the sum of the sensed amplitudes of a second pair of servo signals and the second bit of the Gray code depends on whether the sum of the sensed amplitudes of a third pair of servo signals is greater or less than the sum of the sensed amplitudes of a fourth pair of servo signals.