APPARATUS FOR MEASURING HEAD LEVITATION GAP

摘要

PURPOSE:To measure the levitation gap of a head in a short time by a simple constitution, by a method wherein a monochromatic filter provided with an optically transparent window is interposed in the illumination system of a metal microscope and a spectroscope is arranged to the image forming position of an image forming system to irradiate a photodetector. CONSTITUTION:The levitation state of the floatable head 21 levitating on a rotary disc 20 is illuminated by a white light source 1 through an objective lens 3 and a reflected image is observed through an eyepiece 5. The formed image passing through an image forming lens 4 is spectrally diffracted by the spectral prism 8 arranged at the image forming position thereof to be again formed into an image by a converging lens 10 and said image is detected by a unidimensional photodetector 11 to detect light spectrum intensity distribution. A monchromatic filter having an optical transparent window provided to a part thereof is used in an illumination system and the image thereof is projected on the head 21 to subject a whole image visually observed to monochromatic illumination and the density of monochromatic interference is observed corresponding to the gap between head 21 and the disc 20 and only an objective part is illuminated by a while spot. Therefore, a measuring place is easily confirmed.