Silent retract of heads in a hard disk drive
OwnerBong Jin Leeinventor
Life of this patent
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Abstract
A hard disk drive with an actuator arm assembly that is coupled to a head and includes a voice coil motor. The drive also includes a drive circuit that provides a drive current to the voice coil motor to move the actuator arm assembly into contact with a magnet. The drive circuit limits an amplitude, and/or changes the pulse width, of the drive current as the actuator arm assembly approaches the magnet. Limiting the amplitude and/or changing the pulse widths reduces any audible noise associated with retracting the heads.
Claims14
A hard disk drive, comprising:
- a disk;
- a head coupled to said disk;
- an actuator arm assembly, coupled to said head, includes a voice coil motor;
- a retract magnet for maintaining said actuator arm assembly in a retract position;
- and
- a drive circuit for providing a drive current to said voice coil motor for moving said actuator arm assembly into contact with said retract magnet and limiting an amplitude of said drive current as said actuator arm assembly approaches said retract magnet, said drive circuit having a current comparator.
A hard disk drive, comprising:
- a disk;
- a head coupled to said disk;
- an actuator arm assembly, coupled to said head, includes voice coil motor;
- a retract magnet for maintaining said actuator arm assembly in a retract position;
- and
- a drive circuit for providing a drive current having a series of pulses, each having a width, to said voice coil motor to move said actuator arm assembly into contact with said retract magnet, said drive circuit varies said widths of said pulses of said drive current as said actuator arm assembly approaches said retract magnet, said drive circuit includes a current comparator.
A method for retracting a head from a disk in a hard disk drive, comprising:
- initiating a head retract routine for moving an actuator arm assembly into a retract magnet;
- applying a drive current to a voice coil motor for moving the actuator arm assembly into the retract magnet;
- limiting an amplitude of the drive current;
- and
- varying a width of each of pulses of the drive current as the actuator arm assembly approaches the retract magnet.
A method for retracting a head from a disk in a hard disk drive, comprising:
- initiating a head retract routine for moving an actuator arm assembly into a retract magnet;
- applying a drive current having a plurality of pulses each having a width, to a voice coil motor for moving the actuator arm assembly into the retract magnet;
- and
- increasing the widths of the pulses as the actuator arm assembly approaches the retract magnet.
Dependencies are inferred from the claim text.