Zone servo sector format alignment scheme for servo and spindle motor control

摘要

A zone servo sector format alignment scheme 41 for a disc 22 of a disc drive 20 includes the disc 22 having an outer zone 42, a middle zone 44 and an inner zone 46, each zone having a plurality of tracks 48, 50, 52. The sectors, 54, 56, 58 of each zone 42, 44, 46 includes a plurality of sectors such as sector 60 which define a servo field 62 and a data field 64. The number of sectors 56 in each of tracks 50 of the middle zone 46 is less than the number of sectors 54 on each track 48 of the outer zone 42. The number of sectors 58 on each track 52 of the inner zone 46 is less than the number of sectors 56 on each tracks 50 of the middle zone 46. Further, by maintaining the same recording frequency of the servo fields 62 across all the zones 42, 44, 46, the placing of the sectors 56, 58 in the middle and inner zones 44, 46 can be adjusted in order to provide for alignment indicia 66 which include aligned sectors across all the zones. Such alignment indicia 66 are positioned about the disc 22 and facilitate the operation of the servo control circuit 36 for facilitating head seeking.