Patent ID: 6496315
Filing Date: 2002-12-17
Classification: G11B

Abstract:
A method of operating a disk drive to prevent off-track writing, comprising the steps of:calculating a position error signal Pn at an nth servo position; calculating a head velocity Vn at the nth servo position as (Vn=Pnâˆ’Pnâˆ’1) where Pnâˆ’1 is from a position error signal at an (nâˆ’1) servo position; based on the calculated Pn and Vn and on Un, calculating a predicted PESn+1 as: predicted PESn+1=Pn+Vn+kUn where Un is the output of a servo controller at the nth servo position, and k is a constant; and inhibiting data from being written between the nth servo position and the (n+1) servo position, when absolute values of the calculated Pn, Vn, and predicted PESn+1 meet any of the following conditions: |Pn|>C1â€ƒâ€ƒ(1) |Vn|>C2â€ƒâ€ƒ(2) |Predicted PESn+1>C3â€ƒâ€ƒ(3) where C1, C2, and C3 are constants.