In an optical recording medium having concave and convex type signal pits formed on a substrate surface, a reflection layer is formed on the signal pits in such a manner that a reflection index of an interior of the signal pits is higher than a reflection index at a periphery of the signal pits with...http://www.google.fr/patents/US5410534?utm_source=gb-gplus-shareBrevet US5410534 - Optical information recording medium
