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US 7,804,660 B2Granted
Method for unloading head without calibration in hard disk drives
AssigneeSamsung Electronics Co., Ltd.
InventorsJian Qin Gong, Chang Ik Kang
Life of this patent
Estimating the term…
Abstract
A hard disk drive with a voice coil motor coupled to a head. The disk drive includes a circuit that provides a drive current with a sinusoidal waveform to the voice coil motor during an unload routine. The back emf of the voice coil motor can be determined during a sample period when the current is essentially zero. There is no need to perform a resistance calibration. This reduces the time needed to unload the head.
Claims15
A hard disk drive, comprising:
- a disk;
- a head coupled to said disk;
- an actuator arm coupled to said head;
- a voice coil motor that is coupled to said actuator arm;
- and,
- a drive circuit that provides a drive current with a sinusoidal waveform that passes through zero to said voice coil motor during an unload routine.
3 more elements
A hard disk drive, comprising:
- a disk;
- a head coupled to said disk;
- an actuator arm coupled to said head;
- a voice coil motor that is coupled to said actuator arm;
- and,
- circuit means for providing a drive current with a sinusoidal waveform that passes through zero to said voice coil motor during an unload routine.
3 more elements
A method for unloading a head from a disk in a hard disk drive, comprising:
- initiating an unload routine;
- and,
- applying a drive current that has a sinusoidal waveform that passes through zero to a voice coil motor.
Dependencies are inferred from the claim text.