Patent ID: 8179624
Filing Date: 2012-05-15
Classification: G01R,G11B

Abstract:
1. A method of evaluating a magnetic recording medium using a magnetic head having a reproduction element, the method comprising: (a) recording a signal in a predetermined area of the magnetic recording medium; (b) determining a first value of a reproduction output by magnetically reproducing the predetermined area of the magnetic recording medium without energy line emission; (c) determining a second value of the reproduction output by emitting an energy line having a power of a predetermined value onto the predetermined area and reproducing the predetermined area with the reproduction element during or after the emission of the energy line; (d) calculating an output reduction rate during or after the emission of the energy line with respect to the reproduction output before the emission of the energy line based on the first value and the second value of the reproduction output; and (e) determining a property of the magnetic recording medium based on the calculated output reduction rate with respect to the reproduction output.