| 摘要 |
PURPOSE:To attain the evaluation of floating stability of a disc head with high reliability, by storing a recording medium of a disc device and a head in an enclosed case and reducing the pressure of the inside of the said enclosed case for decreasing the dynamic lift of the head. CONSTITUTION:A standard head 4' having a known floating characteristic in advance is used, a recording medium 3 is rotated at a fixed rotating speed under normal pressure and the inside of the enclosed case 1 is reduced for the pressure with a vacuum pump 8 while monitoring the generating state of sound with an oscilloscope 7. It is taken that the startard head 4' starts contacting the medium when a burst signal starts to be observed on the monitor display attended with the progress of the pressure reduction. The time T when the burst signal is confirmed slightly until the contact limit state is measured. Thus, the criterion of the endurance time T to the limit state of the standard head 4' to be slided with the medium 3 is obtained. A endurance time T' as to a head 4 to be checked having known floating stability is measured with the same condition and the time is compared with the endurance time T' of the standard head 4', allowing to compare and evaluate the floating stability of the head 4 to be checked. |
