Patent ID: 8027121

Claim:
In a servo system for positioning a head laterally to follow lateral motion of a longitudinal tape having at least one longitudinal defined servo track, said servo system comprising a servo sensor configured to sense lateral position of said head with respect to defined servo tracks, a fine actuator configured to translate said head laterally with respect to said longitudinal tape, a coarse actuator configured to translate said fine actuator laterally with respect to said longitudinal tape, and a position error signal loop configured to sense said servo sensor, to determine position error between said head and a desired position related to said at least one defined servo track, and to operate said fine actuator to translate said head laterally in a manner to reduce said determined position error, a method comprising: sensing from said position error signal loop, lateral shift excursion of said at least one defined servo track, comprising determining a maximum value of said determined position error in a first direction; and determining a maximum value of said determined position error in a second direction opposite said first direction; and operating said coarse actuator to position said coarse actuator substantially at a midpoint of said lateral shift excursion of said at least one defined servo track.