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US 6,888,694 B2Granted
Active control system and method for reducing disk fluttering induced track misregistrations
AssigneeAgency for Science, Technology and Research
InventorsGuoxiao Guo, Jingliang Zhang, Zhimin He, Eng Hong Ong
Life of this patent
Estimating the term…
Abstract
The present invention relates to controlling an actuator for positioning a read/write head in storage devices such as disk drives. More specifically, the invention relates to using a sensor to detect the disk vibration amplitude perpendicular to the disk surface, and using feed forward control to cancel or counteract the tendency of the read/write head to deviate off-track due to disk vibration. Various approaches are proposed to detect the disk vertical vibration.
Claims20
An actuator assembly comprising:
- an actuator for supporting a read/write head and for positioning the read/write head adjacent to a magnetic data storage disk, the magnetic data storage disk being rotatable about an axis of the disk and comprising a plurality of substantially concentric data tracks situated about the axis;
- means for detecting displacement of the actuator in an axial direction relative to the disk;
- means for producing an output signal associated with the displacement of the actuator for use in a disk flutter control system;
- and
- means for moving the actuator in a radial direction based at least in part on the output signal.
2 more elements
A magnetic disk drive system comprising:
- a magnetic data storage disk rotatable about an axis of the disk and comprising a plurality of substantially concentric data tracks situated about the axis;
- an actuator supporting a read/write head, for positioning the read/write head adjacent to the data tracks of the magnetic data storage disk;
- means for detecting displacement of the actuator in an axial direction relative to the disk, and for producing an output signal corresponding to said displacement;
- a control system for generating a compensatory control signal from the output signal of the means for detecting, for counteracting effects of disk flutter;
- and
- means for moving the actuator in a radial direction based at least in part on the compensatory control signal.
3 more elements
A magnetic disk drive system comprising:
- a magnetic data storage disk rotatable about an axis of the disk and a plurality of substantially concentric data tracks situated about the axis;
- an actuator supporting a read/write head, for positioning the read/write head adjacent to the data tracks of the magnetic data storage disk;
- means for detecting displacement of the actuator in an axial direction relative to the disk, and for producing an output signal corresponding to said displacement;
- and
- a control system for generating a compensatory control signal from the output signal of the means for detecting, for counteracting effects of disk flutter, wherein the actuator includes a head portion for holding a read/write head, the head portion being supported via a suspension by an arm portion, and wherein the means for detecting is positioned proximal to the suspension and detects axial movement of the suspension, wherein a data cable from the head portion passes over the suspension, and wherein the means for detecting is positioned on or in the data cable.
2 more elements
A magnetic disk drive system comprising:
- a magnetic data storage disk rotatable about an axis of the disk and comprising a plurality of substantially concentric data tracks situated about the axis;
- an actuator supporting a read/write head, for positioning the read/write head adjacent to the data tracks of the magnetic data storage disk;
- means for detecting displacement of the actuator in an axial direction relative to the disk, and for producing an output signal corresponding to said displacement;
- and
- a control system for generating a compensatory control signal from the output signal of the means for detecting, for counteracting effects of disk flutter, wherein the means for detecting comprises an optical sensor mounted on a casing of the magnetic disk drive, operable to optically detect movement of the actuator in an axial direction.
2 more elements
A method of compensating for disk flutter in a hard disk drive system, the method comprising the steps of:
- rotating a magnetic data storage disk about an axis of the disk, the disk having a plurality of substantially concentric data tracks situated about the axis of the disk;
- positioning a read/write head adjacent to the data tracks of the magnetic data storage disk, the read/write head being supported by an actuator;
- detecting displacement of the actuator in an axial direction relative to the disk;
- generating a compensatory control signal from said detected displacement, for compensating for effects of disk flutter;
- and
- moving the actuator in a radial direction based at least in part on the compensatory control signal.
3 more elements
Dependencies are inferred from the claim text.