Patent ID: 8976481
Filing Date: 2015-03-10
Classification: G11B

Abstract:
1. A method for determining touch downs (TDs) of a dynamic flying height (DFH) controlled read/write head against the surface of a rotating disk in a HDD or spin stand comprising: providing a hard disk drive (HDD) or spin stand having a rotatable disk mounted therein; providing the DFH controlled read/write head having at least one heater element and at least one head-disk interference (HDI) sensor capable of generating a DC signal mounted therein, wherein said read/write head is flyable above said rotating disk; then, while rotating said disk, flying said read/write head over said disk; and supplying power to said at least one heater element in a stepwise incremented manner whereby said DFH controlled head approaches a surface of said disk; and analyzing a DC component of a signal generated by said HDI sensor as said power to said DFH head is incremented and whereby said DFH head approaches said surface of said disk; wherein said DC component is generated as a functional relationship between said DC component and said power supplied to said heater element; then processing said relationship to determine a power level step at which a touch down has occurred.