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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsTatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Keizou Miyata, Hiroshi Ryonai
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A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
A master information carrier for writing an information signal into a magnetic record medium, wherein an embossed pattern corresponding to the information signal is formed on a substrate, at least a protruding portion of the embossed pattern is composed of a ferromagnetic material layer having a saturation magnetic flux density more than 0.8 T, and the ferromagnetic material layer composing the protruding portion is not continuous between adjacent protruding portions, but divided by recessed portions.
A master information carrier for writing an information signal into a magnetic record medium, wherein an embossed pattern corresponding to the information signal is formed on a substrate, at least a protruding portion of the embossed pattern is composed of a ferromagnetic material layer having a coercive force not more than 40 kA/m in the inplane direction, and the ferromagnetic material layer composing the protruding portion is not continuous between adjacent protruding portions, but divided by recessed portions.
Dependencies are inferred from the claim text.