Patent ID: 7274635

Claim:
An apparatus for manufacturing a disc medium, the apparatus comprising: means for generating address information having a sync signal including a plurality of sync unit patterns, address data, and an error correction code for the address data; means for making minimum shift keying (MSK) modulation of a carrier signal correspondingly to the address information generated by the means for generating to generate an MSK modulation signal; and means for forming, on the disc medium, a spiral groove wobbled adaptively to the MSK modulation signal generated by the means for modulating, wherein the MSK modulation signal includes at least one modulated part and non-modulated part; wherein the non-modulated part of the MSK modulation signal has a same frequency as that of a carrier signal while the modulated part of the MSK modulation signal has a frequency 1.5 times higher than that of the carrier signal; and wherein the means for making MSK modulation makes MSK modulation of the carrier signal correspondingly to the address information generated by the address information generating means to generate the MSK modulation signal composed of the non-modulated part and modulated part.