Patent ID: 6697203
Filing Date: 2004-02-24
Classification: G11B

Abstract:
A method for determining a thermal decay lifetime of a machine-readable medium at a given temperature, the machine-readable medium having information recorded thereon, the method comprising:writing a test pattern to a portion of the medium; measuring an initial amplitude of signals on the portion of the medium; applying a first stress magnetic field to the portion of the medium; measuring, after the applying of the first stress magnetic field, a first amplitude of signals on the portion of the medium; rewriting the test pattern to the portion of the medium; applying a second stress magnetic field to the portion of the medium; measuring, after the applying of the second stress magnetic field, a second amplitude of signals on the portion of the medium; determining a time to failure corresponding to the, first and the second stress magnetic fields, respectively, the time to failure being an amount of time, measured from a corresponding reference time, for a respective amplitude of the signals on the medium to degrade, in relation to the initial amplitude, beyond a predetermined failure criteria; and determining a time to failure without applying a stress magnetic field based on a relationship between the corresponding times to failure determined for each of the applied stress magnetic fields and Ln(the corresponding times to failure).