OPTICAL DISK, ITS PRODUCTION AND STAMPER FOR DUPRICATING OPTICAL DISK

摘要

PURPOSE: To obtain an optical disk capable of correcting the differences between the track loss signal and push-pull signal in regions where there are prepits and in regions where there are no prepits and improving the reliability of signal characteristics. CONSTITUTION: This optical disk 1 has concentrical or spiral guiding grooves 2 and has the parts where prepit rows are formed (the head part of the recording or rewriting regions or the reproduction-only regions) 6 and the parts where the prepit rows are not formed (the data parts of the recording or rewriting regions). The guiding grooves 2 of the parts where the prepits 3 are adjacent vary in the shape form the guiding grooves 2 of the parts where the prepits 3 are not adjacent. This process for producing such optical disk comprises discretely controlling a laser exposing power in such a manner as to vary the shapes of the guiding grooves of the parts where the prepits are adjacent and the parts where the prepits are not adjacent at the time of exposing an original optical disk.