TD detection with enhanced HDIs signal
AssigneesSAE Magnetics (H.K.) Ltd., Headway Technologies, Inc.
InventorsQinghua Zeng, Soramany Ka, Ellis Cha
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Abstract
A method of operating an HDD having a slider-mounted read/write head that is configured for dynamic fly-height operation (DFH) and includes at least one head-disk interference sensor (HDIs). By operating the DFH to lower the head and subjecting the HDIs signal to a power-law enhancement, a consistent and accurate determination of the touchdown power (TDP) can be obtained. Combining absolute TDP determination with a method for measuring relative changes of FH, an absolute determination of FH can be determined.
Claims16
A method for operating a dynamic flying height (DFH)-configured read/write head to determine a touchdown power (TDP, or TD power), comprising:
- providing a slider-mounted DFH-configured, read/write head operationally installed in a system wherein said read/write head is configured to controllably approach the surface of a rotating recording medium;
- wherein
- said slider-mounted DFH-configured read/write head is mounted on a slider aerodynamically configured to support said DFH-configured read/write head at a stable flying height (FH) above a rotating magnetic recording medium;
- wherein
- said slider-mounted read/write head includes at least one head/disk interference sensor (HDIs) and associated electronic equipment for receiving and processing signals generated by said HDIs;
- wherein
- said slider-mounted read/write head further includes DFH apparatus to raise and lower said slider-mounted read/write head relative to a surface of said rotating recording medium;
- generating an HDIs signal, x(t), as power is applied to said DFH apparatus and said slider-mounted read/write head approaches said surface of said rotating recording medium;
- then
- enhancing said HDIs signal, x(t), by applying a power-law signal processing formula to x(t) to obtain y(t):
- y(t)=(abs(x(t))){circumflex over ( )}np, np=2, 3, . . . ,
- while said approach occurs;
- and
- determining a TDP using said enhanced signal y(t).
A dynamic flying height (DFH)-configured read/write head having an absolutely determined touchdown point (TDP), comprising:
- a slider-mounted DFH-configured, read/write head operationally installed in a system wherein said read/write head is configured to controllably approach the surface of a rotating recording medium;
- wherein
- said slider-mounted DFH-configured read/write head is mounted on a slider aerodynamically configured to support said DFH-configured read/write head at a stable flying height (FH) above a rotating magnetic recording medium;
- wherein
- said slider-mounted DFH-configured read/write head comprises at least one head/disk interference sensor (HDIs) and associated electronic equipment for receiving and processing signals generated by said HDIs;
- wherein
- said slider-mounted read/write head further comprises a DFH apparatus configured to raise and lower said slider-mounted read/write head relative to a surface of said rotating recording medium;
- wherein
- said HDIs is configured to generate a signal, x(t), as power is applied to said DFH apparatus and said slider-mounted read/write head approaches said surface of said rotating recording medium;
- wherein
- said HDIs signal is configured to be processed and enhanced signal y(t) while said approach occurs and a TDP is determined using y(t);
- and
- wherein said read/write head is configured to apply the following power-law transformation to said HDIs signal x(t) to obtain y(t):
- y(t)=(abs(x(t))){circumflex over ( )}np, np=2, 3, . . . , .
Dependencies are inferred from the claim text.