OPTICAL INFORMATION RECORDING MEDIUM AND ITS PRODUCTION

摘要

PURPOSE:To prevent the decrease of the level of a reproduction signal and to eliminate the strains generated in the reproduction signal by adjusting the width of the prepits longer than the diameter of a radiation spot for reproduction of the optical information recording medium at a prescribed value with respect to the diameter of the radiation spot. CONSTITUTION:The sector mark pit 3 of the optical information recording medium is formed longer than the diameter phi of the radiation spot 8 for reproduction and all the address pits 5 and synchronizing pits 6 included in an ID pit array 4 are formed shorter than the spot 8. Pregrooves 7 are formed at the width S nearly equal to the width of the pits 3, 5, 6 which are respectively prepitted. The track pitch P thereof is so determined that the peripheral part of the spot 8 is irradiated in the range of 1/2-1 times the width S of the pregrooves. The pits are formed to the relation of phi/4