Patent ID: 6137753
Filing Date: 2000-10-24
Classification: G11B

Abstract:
In a data-storage device that includes a rotatable disc and a data head for accessing the disc, a runout calibration system comprising:positioning mechanics coupled to the head for moving the head relative to the disc;a servo loop incorporating said positioning mechanics and generating a first drive signal used to control said positioning mechanics; anda memory having an input and an output coupled to said loop for recording a plurality of samples of said first drive signal at a plurality of periodic angular increments of the disc during one or more rotations of the disc, wherein said input is coupled to said loop at only one node when recording, and repeatedly playing back said samples into said loop at said plurality of periodic angular increments during multiple rotations of the disc that are subsequent to said one or more rotations, wherein each of said plurality of samples is recorded and played back at the same periodic angular increment and each of said samples is retained without modification in said memory during playback.