Hard disk drive head-disk interface dithering
AssigneeWestern Digital Technologies, Inc.
InventorsSripathi V Canchi, Sukumar Rajauria, James W Reiner, Erhard Schreck
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Abstract
A procedure for accurately determining thermal flying height control (TFC) touchdown power associated with a head-disk interface (HDI) in a hard disk drive (HDD) involves dithering the spacing corresponding to the HDI by applying an oscillating signal. The touchdown power with the HDI dithering applied is determined and, based on that and the dithering amplitude, the touchdown power without dithering applied, as well as the back-off power, is determinable.
Claims21
A method for determining touchdown power associated with a head-disk interface (HDI) in a hard disk drive (HDD), the method comprising:
- dithering the spacing corresponding to said HDI by applying an oscillating signal;
- determining touchdown power with HDI dithering applied;
- based on said touchdown power with HDI dithering applied, determining touchdown power without HDI dithering applied;
- and
- storing, within said HDD, a characterization of said touchdown power without dithering applied.
A hard disk drive (HDD) comprising:
- a disk medium rotatably mounted on a spindle;
- a head slider comprising a read/write head configured to read from and to write to said disk medium;
- a voice coil actuator configured to move said head slider to access portions of said disk medium;
- and
- a least one electronic component comprising one or more sequences of instructions which, when executed by one or more processors, cause performance of:
- dithering the spacing between said head slider and said disk medium by applying an oscillating signal;
- determining touchdown power with head-disk interface (HDI) dithering applied;
- based on said touchdown power with HDI dithering applied, determining touchdown power without HDI dithering applied;
- storing, within said HDD, a characterization of said touchdown power without dithering applied;
- and
- providing a back-off power signal to a thermal flying height control (TFC) heater element to achieve a particular spacing between said head slider and said disk medium.
An electronic component manufacture comprising one or more sequences of instructions which, when executed by one or more processors, cause performance of:
- dithering the spacing between a head slider and a disk medium by applying an oscillating signal;
- determining touchdown power with head-disk interface (HDI) dithering applied;
- and
- based on said touchdown power with HDI dithering applied, determining touchdown power without HDI dithering applied.
Dependencies are inferred from the claim text.