Adaptive servo gap detection for sequence servo

Application Number: 00108591
Application Date: 2000.05.18
Publication Number: 1274909
Publication Date: 2000.11.29
Priority Information: 1999/5/19 US 09/314,078
International: G11B5/58;G11B21/10
Applicant(s) Name: International Business Machine Corp.
Inventor(s) Name: Enhan Xuan Bu;Sakita Junichi;Grenn Alai Jekwit
Patent Agency Code: 11038
Patent Agent: feng xun
Abstract Disclosed are a method and a detector for adaptively detecting servo gaps in a timing based servo pattern prerecorded on a variable velocity media. The timing based servo pattern has groups of repeated pairs of non-parallel transition stripes arranged in bursts, the bursts separated by servo gaps whose length is variable. A servo system sensor senses the transition stripes in the longitudinal direction of the media. A group interval detector detects the timing interval between the same slope transition stripes of two sequential groups. A divider divides the detected group timing interval by a predetermined divisor to provide a divided timing interval gap detection threshold. A sequential stripe interval detector measures the timing interval between stripes, and a comparator compares the divided timing interval and the timing interval.