Contact Monitor Technique for Fly Height Testing of Recording Heads
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
This technique prevents damage to recording heads and disks by monitoring contacts. One technique for testing the flying height of magnetic recording heads as well as other heads is optical measurement of interference fringes between the slider surface and a quartz (or glass) disk. A problem with this technique is that contamination causes head/disk contacts not visible in the interference fringes. A way of automatically preventing damage to the disk or to the head is as follows: l) Mount a motion transducer (or an array of such transducers) onto the underside of the glass disk and bring electrical contacts off through a coaxial spinning connector, such as a mercury contact. 2) Use a preamplifier, if necessary, very near the disk assembly to minimize noise. 3) Monitor the signal from the transducer(s).