Patent ID: 7110208

Claim:
A method for improving servo performance in a disk drive having a transducer and a disk with a plurality of concentric tracks each identified by a track number, wherein each track has a plurality of first-type servo sectors providing track identification information for determining a track's number and providing track position information for determining a position error signal between the transducer's position and a reference position, and has a plurality of second-type servo sectors providing track position information including an odd/even property for the track's number but not providing track identification information for determining the track's number, the second-type servo sectors being interspersed between the first-type servo sectors such that each first-type servo sector is separated from another first-type servo sector by at least one second-type servo sector, and wherein the servo sectors are separated by respective data regions, the method comprising: reading track identification information and track position information from a first-type servo sector; estimating a track number and a transducer position for a second-type servo sector immediately following the first-type servo sector; reading track position information from the immediately following second-type servo sector; comparing the odd/even property from the immediately following second-type servo sector with an odd/even property for the estimated track number; if the odd/even property from the second-type servo sector does not match the odd/even property of the estimated track number, then adjusting the odd/even property of the estimated track number by changing the track number by one track number such that the odd/even property of the estimated track number matches the odd/even property from the second-type servo sector; and determining a position error signal between the transducer's position and a reference position using the adjusted track number and the track position information read from the immediately following second-type servo sector.