Appeal No. 1998-3369
Application No. 08/546,295
that positions the actuator. Claim 1 is illustrative of the
claimed invention, and it reads as follows:
1. A disc drive having a disc and an actuator adjacent
the disc, the disc having a plurality of concentric data
tracks, the actuator having a coil of a voice coil motor, the
disc drive having control circuitry for positioning the
actuator with respect to a selected data track, the control
circuitry including driver circuitry for driving the voice
coil motor to position the actuator through the controlled
application of current to the coil, the disc drive comprising:
voltage generation means for generating a plurality of
discrete voltage levels; and
retraction means, responsive to the voltage generation
means, for applying the discrete voltage levels as a
series of timed, stepped voltages of increased
magnitude to the driver circuitry to retract the
actuator to a park position, the retraction means
applying the series regardless of the initial radial
position of the actuator, the retraction means
causing the driver circuitry to operate as a voltage
source for the coil so that voltages established
across the coil by the driver circuitry are
maintained regardless of the flow of current through
the coil as the actuator is retracted.
The prior art references of record relied upon by the
examiner in rejecting the appealed claims are:
Onodera 4,807,062 Feb. 21,
1989
Nakatsu et al. (Nakatsu) 4,887,254 Dec.
12, 1989
Touchton et al. (Touchton) 4,967,291 Oct. 30,
1990
2
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