Master information carrier for magnetic transfer

摘要

A master information carrier for magnetic transfer has a concentric irregularity pattern representing information to be transferred to a disc-like magnetic recording medium. The top surface of the protruding portions of the irregularity pattern is formed of magnetic material. The irregularity pattern is formed so that the width L ÄnmÜ in a circumferential direction of a protruding portion at a distance R ÄnmÜ from the center satisfies the condition L= alpha ( omega . DELTA T.R), 0.8 wherein omega represents in Ärad/secÜ the angular velocity of the magnetic recording medium when a signal is read out from the magnetic recording medium after the magnetic transfer and DELTA T represents in ÄsecÜ 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. A master information carrier for magnetic transfer has a concentric irregularity pattern representing information to be transferred to a disc-like magnetic recording medium. The top surface of the protruding portions of the irregularity pattern is formed of magnetic material. The irregularity pattern is formed so that the width L ÄnmÜ in a circumferential direction of a protruding portion at a distance R ÄnmÜ from the center satisfies the condition L= alpha ( omega . DELTA T.R), 0.8 wherein omega represents in Ärad/secÜ the angular velocity of the magnetic recording medium when a signal is read out from the magnetic recording medium after the magnetic transfer and DELTA T represents in ÄsecÜ 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.