Experimental analysis of displacements of read/write heads upon floppy-disk media

Abstract: The measurement of low-amplitude vibration of small mechanisms is a difficult problem. This paper presents the results of a study to develop a nonobtrusive optical method capable of producing quantitative analog outputs. The fruit of this work has been the development of a device denoted as a laser reflectometer which can detect rotations as small as 2 mgrrad and displacements on the order of 10^–4 in. in the present configuration. The device was implemented in the analysis of read/write head motion upon a traveling floppy disk.