发明名称 |
Measurement of spacing fluctuation |
摘要 |
A method for determining the surface distortions of a disk in a spin-stand or single or multiple disk hard disk drive (HDD) utilizing a DFH type write head. A stepwise power curve is supplied to the DFH head, the head is flown over a chosen track on the disk, and the high frequency signal from a HDI sensor is analyzed in order to determine the step of an initial touchdown power and the step of a complete touchdown power as a function of individual sectors in a sector subdivision along a chosen track. The HDI sensor signal is averaged within each step of the power curve between these two steps and a Ratio variable, Ratio=(Max. amplitude)/(RMS amplitude) is calculated for each step and is averaged over each rotation of the disk during the step. |
申请公布号 |
US8717702(B2) |
申请公布日期 |
2014.05.06 |
申请号 |
US201213424617 |
申请日期 |
2012.03.20 |
申请人 |
ZENG QINGHUA;CHA ELLIS;KA SORAMANY;SAE MAGNETICS (HK) LID.;HEADWAY TECHNOLOGIES, INC. |
发明人 |
ZENG QINGHUA;CHA ELLIS;KA SORAMANY |
分类号 |
G11B21/02 |
主分类号 |
G11B21/02 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|