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:
Oct. 07, 1997
Filed:
Dec. 08, 1994
Richard W Molstad, St. Paul, MN (US);
Robert J Youngquist, White Bear Lake, MN (US);
Bennett G Dy, St. Paul, MN (US);
Imation Corp., St. Paul, MN (US);
Abstract
A track pitch error compensation system for tape drives of the type configured for reading data from and/or writing data to magnetic tape having adjacent servo tracks with apparent centerlines spaced about a tracking axis. The tape drive includes a multichannel head assembly having a plurality of channels of read gaps which produce position error signals (PES) representative of positions of the read gaps on the tracking axis with respect to the apparent centerlines of servo tracks on the tape, a positioner responsive to positioner drive signals for driving and positioning the head assembly on the tracking axis with respect to the servo tracks, and a servo control system connected between the head assembly and positioner for generating positioner drive signals causing a servoing read gap to be servo locked to a desired servo track as a function of the PES when operated in a closed-loop servo mode. The method includes determining and storing one or more track pitch error values for each magnetic tape, and determining a gain constant of the servo system. PES correction offsets representative of the magnitudes of positioner drive signals causing the positioner to drive the head assembly distances sufficient to compensate for the track pitch errors are calculated as a function of the track pitch errors and the gain constant, and stored. During closed-loop servo mode operation the PES correction offset is summed with the PES to cause the servoing read gap to be servo locked to the desired centerlines of the servo tracks.