Patent ID: 7781146
Filing Date: 2010-08-24
Classification: G11B,Y10S

Abstract:
1. An optical recording medium comprising a substrate, a protective layer and a plurality of information recording layers between the substrate and the protective layer which are laminated via at least one intermediate transparent layer and capable of recording data in the plurality of information recording layers and reproducing data recorded in the plurality of information recording layers by projecting a laser beam via a light incidence plane constituted by one surfaces of the substrate or one surface of the protective layer onto the plurality of information recording layers, at least one information recording layer other than a farthest information recording layer from the light incidence plane among the plurality of information recording layers including at least one recording film, a first dielectric film located on a side of the light incidence plane with respect to the at least one recording film and containing an oxide as a primary component and added with nitrogen, and a second dielectric film located on an opposite side of the light incidence plane with respect to the at least one recording film and having a lower thermal conductivity than that of the first dielectric film, wherein the at least one information recording layer is constituted by a first recording film containing one element selected from a group consisting of Si, Ge, Sn, Mg, In, Zn, Bi and Al as a primary component and a second recording film provided in a vicinity of the first recording film and containing one element selected from a group consisting of Cu, Al, Zn, Ti and Ag and different from the element contained in the first recording film as a primary component and when the laser beam is projected, the element contained in the first recording film as the primary component and the element contained in the second recording film as the primary component are mixed with each other, thereby forming a record mark.