Method and apparatus for reducing and dispersing wear to the surface of a
rotatable disc in a disc drive using an adaptive dither process. The disc
drive includes an actuator assembly that is secured in a parked position
by a latch when not in use. The method includes determining an open latch
current required to open the latch as the actuator assembly is moved from
the parked position to a position over a user data storage portion of the
disc. A dither current is subsequently applied to the actuator assembly to
induce a reciprocating lateral displacement of the actuator assembly when
the actuator assembly is secured in the parked position, wherein the
maximum amplitude of the dither current is selected to be less than the
open latch current.
