Surfacing Margin inspection manner and surfacing Margin survey instrument null of

摘要

PROBLEM TO BE SOLVED: To perform inspection at high accuracy while mounting a magnetic disc drive by placing the magnetic disc drive in a chamber under a specified atmospheric pressure, recording a contact inspection signal and reproducing it as a reproduction signal output, repeating the recording/reproduction while lowering the atmospheric pressure and determining the difference between a specified atmospheric pressure and an atmospheric pressure, where the variation of reproduced signal output with respect to the atmospheric pressure is substantially zero, as a floating margin. ;SOLUTION: After a floating margin inspection data generated from the write signal generation circuit 5 of a magnetic disc drive 1 is written on a medium in an HDA 2, the data is read out by an R/W circuit 4 and the output of a reproduction signal (a) is measured. The atmospheric pressure is then lowered sequentially, and the reproduction signal (a) is measured under each state. Floating amount decreases as the atmospheric pressure lowers but the reproduction signal (a) is increased because the magnetic spacing is decreased. At the moment of time when the magnetic spacing becomes 0, the reproduction signal (a) is no increased even if the atmospheric pressure is lowered furthermore. At the moment of time when the magnetic spacing is saturated, floating margin is 0 and the head touches the disc.;COPYRIGHT: (C)1998,JPO