Appeal No. 1998-1819
Application No. 08/364,972
According to the statement of the rejection applied against instant claim 1 (Answer
at 3-4), Good reveals a method of fly height servo control of a read/write suspension.
Although Good does not disclose sensing tension and compression in the suspension,
Sakamoto is deemed to disclose a strain gauge 15 (Fig. 5) that provides a deflection
signal, enabling the system to track head position relative to the rest position.
Appellants argue, inter alia, that the combination is not well founded because
Sakamoto teaches tracking, rather than controlling flying height of a head. (Brief at 8.)
Additionally, appellants allege there is no teaching that the device of Good would
necessarily be improved by applying the teachings of Sakamoto. (Id. at 9.) Appellants
further allege (id. at 10) that the artisan would recognize that the "resistive wire" of
Sakamoto could not measure compression.
Good teaches adjusting fly height of read/write heads in multiple disk drives. The
reference discloses that the read signal for the fly height servo is picked up off the data
channel, and sampled by digitizing switching circuitry in Harmonic Ratio Fly height detector
(HRF) 28. See Good, Figs. 1, 5, and col. 3, ll 45-59. Circumferential variation in fly height
is corrected in real time by a PID controller. Radial variation in fly height is corrected by
feeding forward a correction from profile storage controller 32 during track seek
operations. Id. at col. 4, ll 1-9. A radial correction value for each head at each cylinder
position is determined during a calibration procedure. Id. at ll 19-28. Fly height correction
-4-
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