Optics: measuring and testing – By dispersed light spectroscopy – Utilizing a spectrometer
Patent
1993-04-29
1995-12-05
Turner, Samuel A.
Optics: measuring and testing
By dispersed light spectroscopy
Utilizing a spectrometer
356357, G01B 902
Patent
active
054734312
ABSTRACT:
A device for accurately measuring flying heights of a read/write head in a disk drive down to zero microinches using interferometry, wherein the flying height of the head above the disk surface is calculated by directing white light to the under side of a rotating disk. An interference pattern is obtained by reflecting a first portion of the light off of the top surface of the disk and reflecting a second portion of the light off of the underside of the read/write head, and then recombining the first and second portions of light. The interference pattern is then input to a spectrophotometer, which creates an intensity profile from which the flying height of the read/write head above the disk may be calculated. A spacer layer is provided on the upper surface of the disk to increase the phase difference of the first and second portions of light, thereby allowing clear interpretation of the interference pattern at extremely low flying heights.
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Danson David P.
Hollars Dennis R.
Conner Peripherals, Inc.
Turner Samuel A.
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