Patent ID: 6667947
Filing Date: 2003-12-23
Classification: G11B

Abstract:
An optical multi-layer information recording medium for recording information therein and/or retrieving information therefrom upon radiation of a convergent beam of light comprising:at least two pairs of recording layers and light-transmissive layers stacked one after another, wherein a first recording layer proximal to a beam radiation side and a second recording layer distal from the beam radiation side are made from a material that satisfies the following equation: (TrxÃ—TrzÃ—Aby)/Abx&ap;(NAy)2/(NAx)2 where Trx represents transmissivity of the first recording layer, Trz represents a sum of transmissivity of recording layer(s) and light transmissive layer(s) stacked between the first and second recording layers, Aby represents absorptance of the second recording layer, Abx represents absorptance of the first recording layer, NAy represents a numerical aperture on the second recording layer and NAx represents a numerical aperture of the first recording layer.