TD detection with enhanced HDIs signal

1. 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).

2. The method of claim 1 wherein said TDP provides an absolute reference point whereby a method of determining relative changes in slider height can be combined with said absolute reference point to create a method to determine a flying height (FH) of said slider-mounted read/write head.

3. The method of claim 1 wherein in said signal processing formula:

y ( t )=(abs( x ( t ))){circumflex over ( )} np, np= 2,3, . . . ,

np can be chosen to produce an optimal comparison with an independent measuring device.

4. The method of claim 3 wherein np is an even integer and the absolute value of x(t) is its positive value.

5. The method of claim 3 wherein said independent measuring device is a laser doppler vibrometer (LDV).

6. The method of claim 1 wherein said signal processing further includes a step of filtering, either before or after said enhancement of the signal.

7. The method of claim 1 wherein said signal processing further includes a step of signal amplification either before or after said enhancement of the signal.

8. The method of claim 1 applied to the manufacture of active HDD components, said components including a slider and/or a head gimbal assembly (HGA) and said application occurring during electric or dynamic electric test (ET, or DET) during manufacturing of said HDD components (slider and/or HGA).

9. 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, . . . , .

10. The DFH-configured read/write head claim 9 wherein said TDP provides an absolute reference point wherein, by combining said absolute TDP with a method of determining relative changes in slider height a flying height (FH) of said slider-mounted read/write head is obtained.

11. The DFH-configured read/write head of claim 9 wherein in the use of the power-law signal processing formula:

y ( t )=(abs( x ( t ))){circumflex over ( )} np, np= 2,3, . . . ,

np can be chosen to produce an optimal comparison with an independent measuring device.

12. The DFH-configured read/write head of claim 11 wherein said independent measuring device is a laser doppler vibrometer (LDV).

13. The DFH-configured read/write head of claim 9 wherein said signal processing further includes a step of filtering, either before or after said enhancement of the signal.

14. The DFH-configured read/write head of claim 9 wherein said signal processing further includes a step of signal amplification either before or after said enhancement of the signal.

15. A head-gimbal assembly, comprising:

the DFH-configured read/write head of claim 9 ; a suspension that elastically supports said DFH-configured read/write head;

a flexure affixed to said suspension and a load beam having one end attached to said flexure and another end attached to a base plate.

16. A hard disk drive (HDD), comprising:

said head gimbal assembly of claim 15 ;

a magnetic recording medium positioned opposite to said DFH-configured read/write head;

a spindle motor that rotates and drives said magnetic recording medium;

a device that positions said DFH-configured read/write head relative to said magnetic recording medium.