Interferometric spacing measurements of the Bernoulli head/disk interface

Head-to-disk spacing in a flexible disk drive (Bernoulli technology) is measured interferometrically using monochromatic light in conjunction with a grey level interpolation scheme. Measurements in the center region of a Bernoulli head indicate that the minimum head-disk separation is less than 50 nm, suggesting that the asperity contacts occur in the area of the closest approach. The spacing distribution of a typical Bernoulli head is reported, as well as a parameter study of spacing as a function of rotational speed.<
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