Patent ID: 6833969
Filing Date: 2004-12-21
Classification: B82Y,G11B

Abstract:
A master information carrier for magnetic transfer having on the surface thereof a concentric irregularity pattern representing information to be transferred to a disc-like magnetic recording medium, at least the top surface of the protruding portions of the irregularity pattern being formed of magnetic material, wherein the improvement comprises thatthe irregularity pattern is formed so that the width L [nm] in a circumferential direction of a protruding portion at a distance R [nm] from the center satisfies the condition L=&agr;(&ohgr;Â·&Dgr;TÂ·R), 0.8&lE;&agr;&lE;1.4, wherein &ohgr; represents in [rad/sec] the angular velocity of the magnetic recording medium when a signal is read out from the magnetic recording medium after the magnetic transfer and &Dgr;T represents in [sec] a desired signal time width of a reproduction signal waveform in a magnetization transition region corresponding to an interval between the ends of the protruding portion in the circumferential direction.