Patent ID: 8059362

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 at least one 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 at least one 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, the method comprising: sensing from said position error signal loop, lateral shift excursion of said at least one defined servo track; determining a maximum positive peak and a maximum negative peak of said lateral shift excursion; and operating said coarse actuator to position said coarse actuator substantially at a midpoint of said maximum positive peak and said maximum negative peak of said lateral shift excursion of said at least one defined servo track.