The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 1995
Filed:
Apr. 29, 1993
Dennis R Hollars, Los Gatos, CA (US);
David P Danson, Niwot, CO (US);
Conner Peripherals, Inc., San Jose, CA (US);
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.