To facilitate the design of a drive device and to attain the supply of the low cost drive by supplying a medium having satisfied uniformity of the recording performance and also having the stable mechanical property.
The address information is recorded by the deflecting operation on at least one segment while keeping the groove width, and the segment whereon the address information is recorded is arranged at the top of the data area which is a recording/reproducing unit. Land part wherein the grooves are broken off, or the area wherein the shape of the groove is partially deformed, or the area consisting of these combination are provided among all the grooves, then the clock reproducing signal is obtained from the above area for the data recording/reproducing operation.
ITO SHO
SHIMAZAKI KATSUSUKE
NAGATAKI YOSHIYUKI
WATANABE HITOSHI
