Patent ID: 6965491
Filing Date: 2005-11-15
Classification: G11B

Abstract:
1. A method of determining written in runout (WRO) in a disk drive, wherein the disk drive includes a data recording disk and a transducer head, the disk includes a servo wedge and first and second tracks, the servo wedge extends radially across the tracks and include includes circumferentially sequential, radially offset servo bursts, the tracks are adjacent to one another, the first track has a track width, the first track includes a first track centerline, the second track includes a second track centerline, the track centerlines are separated from one another by a track spacing, and the head reads data from and writes data to the tracks, the method comprising the steps of: (a) positioning the head at a first radial position relative to the tracks; (b) reading a first combination of the servo bursts using the head at the first radial position during a first revolution of the disk to generate first readback signals; (c) measuring first burst signals from the first readback signals; (d) obtaining a combination of the first burst signals to generate a first burst phase; (e) positioning the head at a second radial position relative to the tracks; (f) reading a second combination of the servo bursts using the head at the second radial position during a second revolution of the disk to generate second readback signals; (g) measuring second burst signals from the second readback signals; (h) obtaining a combination of the second burst signals to generate a second burst phase; and (i) determining an WRO for the first track using the burst phases, wherein the WRO indicates the track spacing.