OPTICAL INFORMATION CARRIER WITH MOSSAIC STRUCTURE

摘要

Optical information carrier comprising a substrate with an optically readable information structure, readable by means of a light beam. A flat optically transparent layer is present onto the substrate, which layer is in correspondance with the information structure divided in at least two groups of areas, whereby the areas of one group have mutually the same optical refractive index and the refractive indexes of the areas of both groups differ at least 0.2 from each other. The thickness of the optically transparent layer is selected such that dependent onto the difference in optical refractive index and dependent onto the wave length of the light of the scanning light beam an optical path length difference between the light beams scanning the areas of both groups is realized equal to or approximately equal to a half wave length or and odd multiple thereof.