Dynamic magnetic information storage or retrieval – Head mounting – For moving head into/out of transducing position
Reexamination Certificate
1999-02-17
2001-10-09
Ometz, David L. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
For moving head into/out of transducing position
C360S075000, C360S294400
Reexamination Certificate
active
06301080
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to disk drives, and particularly to a gimbal-level piezoelectric microactuator for read/write heads for disk drives.
One of the major problems of using high suction air bearings in load/unload application shows up during the unloading of the heads. The negative suction forces induces an impulse loading contributing to the excitation of the head-gimbal assembly (“hga”). In addition to the excitation of the head-gimbal assembly, the hga is required to travel up the ramp a considerable distance before the system is able to overcome the suction force. The unload travel distance up the ramp translates into valuable unused real estate at the outside diameter of the disc.
Accordingly, there is a need in the art for an actuator for supporting and finely-positioning a read and/or write hga with sufficient accuracy and to operate with a minimum of unused real estate, namely substantially below that possible with typically known systems.
SUMMARY OF THE INVENTION
A head gimbal assembly on a suspension is loaded relative to a disk. A ramp facilitates the loading and unloading of the head relative to the disk. An air bearing effectively regulates the head and gimbal assembly and disk location. Unloading a suction air bearing when the head is unloaded from the disc comprises applying an excitation to the air bearing during unloading to effect a perturbation in the air bearing. The air bearing is a suction bearing, and an excitation pertubates at least one of the modes of the leading edge, trailing edge or roll mode.
A single or multiple air bearing modes can be excited during unload operation of the air bearing. A sweep function containing one or several air bearing modes to perturb the air bearing and cause an instability which eases unloading of the heads.
A microactuator can be used to generate the excitation. In case the excitation frequencies are low, the voice coil system can then be used. The amplitude of the excitation may be varied throughout the excitation. In some forms of the invention the gimbal modes, namely either twist and/or bending modes, can be excited to increase the forces acting on the air bearing contributing to overcome the suction forces.
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Merchant & Gould P.C.
Ometz David L.
Seagate Technology LLC
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