透過形マイケルソン干渉を利用したヘッド浮上すきまの較正不要な測定法

概要

論文の詳細を見る
A novel spacing measurement using the Michelson laser interferometry was enhanced to permit a direct measurement of head-disk spacing without necessity of calibration. This method utilizes the phase comparison of two kinds of interference fringe patterns formed over the slider lubricating surface and the inner back surface of a glass disk. To increase resolution and reproducibility, three principal techniques were newly introduced; an optical system mounting a hi-definition CCD camera, a wobbling technique to capture fringe image, and powerful ridgeline extraction from the fringe pattern. These techniques were confirmed to improve the reproducibility to less than a standard deviation of 1nm. To derive the absolute spacing value from the observed value, pseudo phase shift, which is generated by superimpose of the light beam reflected on the glass inner surface, must be cancelled. For this purpose, the phase shift was calculated under the multiple beam interference considering phase delay on the conductive slider material, and thus procedure for the cancellation was established. Finally, the measured spacing and the calculated spacing were found to be in good accordance, indicating the present method to be applicable to the practical usage.
一般社団法人日本機械学会の論文
2001-10-25