| 摘要 |
The invention provides an apparatus for measuring the flying height and orientation of a magnetic head (54) relative to a transparent disk (20) based on both frustrated total internal reflection and total internal reflection. The apparatus comprises a housing (10) that mounts an electric motor (12) which rotationally supports the aforementioned disk. The disk (20) has a tapered lateral surface (20c) with light emitting means (22) such as a laser (24) installed on one side of the disk lateral surface and a flat light detecting means (30) on a side of the disk diametrically opposite to the laser. A second light detector (130) is disposed on the other side of the disk (20) from, and opposite the head (54). The light is emitted from the laser (24) and is directed to the disk (20) perpendicular to the tapered lateral surface (20c) of the disk (20). When the magnetic head (44) to be tested is absent, the light detecting means (30) shows an area of homogeneous intensity of the reflected light. When, however, the magnetic head (44) approaches to the surface (20a) of the disk and is supported during rotation of the disk at a flying height, i.e., on an air cushion, the proximity of the head frustrates the total internal reflection. As a result, the intensity of the reflected light sensed by the detector (38) is reduced. The degree of this reduction and that detected by detector (130) can be translated through appropriate electronic means and computer (40) into the value of the flying height.
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