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:
Jan. 30, 1996
Filed:
Aug. 18, 1994
George F Adams, Tucson, AZ (US);
Vincent N Kahwaty, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A magnetic head assembly is provided which has top and bottom zones for processing a magnetic tape alternately in opposite directions. Each zone contains a top write element and read element pair and a bottom write element and read element pair, the write element of each pair being located on a first gap line and the read element of each pair being located on a second gap line. Located between the read elements on the second gap line are a plurality of servo elements. The pitch of the servo elements is a multiple of the track pitch of the magnetic tape and the pitch of the write elements is a multiple of the pitch of the servo elements. The servo elements are totally dedicated to servoing on pre-recorded servo tracks on the magnetic tape. A servo element on the first gap line is on a common servo track with one of the servo elements on the second gap line so as to provide a pair of servos on the same servo track. During initialization of the tape drive, this pair of servo elements transmits signals to compensate for any track misregistration (TMR) due to head assembly inaccuracies during fabrication or tape skew. The bottom zone of the head assembly is a mirror image of the top zone. Each of the servo elements in the same gap line sequentially servo through all of the servo tracks so that the write elements in the same gap line can write a top and bottom sets of data tracks. When one servo element transition through all of the servo tracks, then the adjacent servo takes over and transitions through all of the servo tracks and so on until all of the sets of write tracks have been completed. This servoing and writing operation alternates between the top and bottom zones sequentially as the tape reverses its direction, one tape pitch at a time. When one of the zones is operational, one of its servos is a primary servo and the mirror image of this servo in the opposite zone serves as a back-up auxiliary servo for maintaining the write elements on track. When a scratch or tape defect is detected by the primary servo, control is transferred to the auxiliary servo to maintain the write elements on track.