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:
Sep. 21, 1993
Filed:
Mar. 30, 1990
Michael D Sidman, Colorado Springs, CO (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A disk drive system wherein the radial position of a sensing head is servoed using signals derived from the sensing of servo signals recorded in circular tracks on a disk surface and disposed in circumferentially spaced sets thereof, each set comprising radially aligned signals in a succession of tracks, where the derived signals vary cyclically as a function of the radio position of the head. The DC offsets of the derived signals relative to a reference level are removed by causing a constant velocity radial displacement of the head and, for each of the derived signals, measuring the durations of the positive and negative half-cycles of the derived signal relative to the reference level and adding to the derived signal an offset voltage sufficient to equalize the durations.