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US 9,754,620 B2Granted
Bimodal modulation
AssigneeSeagate Technology LLC
InventorsVijay Kumar, Narayanan Ramakrishnan
Life of this patent
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Abstract
An apparatus and associated method contemplating a head gimbal assembly (HGA) and a bridge circuit including first and second microactuators attached to the HGA. Computation logic is connected to the bridge circuit and configured to independently measure an electrical output of each microactuator and to sum the electrical outputs to derive a value related to a vertically dominant modulation mode of the HGA.
Claims19
An apparatus comprising:
- a head gimbal assembly (HGA);
- a bridge circuit including first and second microactuators attached to the HGA;
- and
- a computation module connected to the bridge circuit and configured to independently measure an electrical output of each microactuator and to sum the electrical outputs to derive a value related to a bimodal modulation of the HGA.
1 more element
An apparatus comprising:
- a pair of opposing-effect piezoelectric microactuators configured to selectively position the apparatus;
- and
- a variable-frequency excitation source configured to drive each of the microactuators.
A method comprising:
- obtaining a head gimbal assembly (HGA) having a pair of opposing-effect microactuators supporting a read/write head adjacent a data storage media, a variable frequency excitation source configured to drive each of the microactuators, and a computation module configured to individually read an electrical output of each microactuator;
- and
- exciting the microactuators to obtain a spectral frequency response function (FRF) of the HGA.
Dependencies are inferred from the claim text.