Non-contact measurement of slider fly height by electrostatic force
AssigneeSAE Magnetics (H.K.) Ltd.
InventorsLi-Yan Zhu, Chao-Hui Yang, Yen Fu, Ellis T. Cha
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Abstract
In a system and method for a non-contact measurement of the fly height of a slider above a magnetic data storage medium using electrostatic force, a slider with a read/write head flies over a magnetic data storage medium. A series of distinct voltages are applied between the slider and the magnetic data storage medium, and corresponding read-back signals are recorded. Using the recorded read-back signals, coefficients for an empirical curve-fit equation are calculated. The coefficients are normalized and converted into a fly height measurement.
Claims6
A disk drive for implementing a slider fly height measurement, comprising:
- a slider with a read/write head having a set of read elements to read data and a set of write elements to write data;
- a suspension to support the slider and maintain a spacing between the slider and the magnetic data storage medium;
- a magnetic data storage medium to store data, wherein said data can include constant wavelength signals for minimizing read-back amplitude fluctuation at a fixed spacing during the fly height measurement;
- a power source to provide a variable control voltage to the spacing between the slider and the magnetic data storage medium thereby changing said spacing and producing a corresponding measurable variation in a track read-back signal amplitude;
- a means of measuring an averaged value of said track read-back signal amplitude corresponding to said variable control voltage;
- a quadratic curve-fitting algorithm implemented in the drive to extract a set of coefficients from said track-averaged read-back signal amplitudes and to obtain a value of the fly height thereby.
Dependencies are inferred from the claim text.