OPTICAL INFORMATION RECORDING MEDIUM,ORIGINAL DISK FOR OPTICAL INFORMATION RECORDING MEDIUM,AND METHOD OF MANUFACTURING THE ORIGINAL DISK

摘要

An optical information recording medium having a land face and a groove face both used as recording tracks and capable of providing high quality of signals, comprising both the land and groove faces formed as the recording tracks on the substrate, wherein laser beam is radiated from the rear side of the substrate for recording and reproducing, the inclination angle of the groove face comes within the range of 25°to 40°, and the arithmetic averaged roughnesses (Ra) of both the land face and the groove face are 0.2 to 0.7 nm, respectively.