Information recording medium
View Patent ↗In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32 . The information recording medium is characterized in that both push-pull signal outputs T 1 and T 2 , which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5≧T 1 /T 2 ≧0.5.
1. An information recording medium comprising at least a substrate, a recording layer, and a resin layer,
wherein said substrate is formed with a read only area and a recording/reproducing area, and wherein said read only area and said recording/reproducing area do not overlap with each other, and
wherein a reflectivity of said recording layer is more than 10%, and
wherein said recording layer and said resin layer are formed continuously over at least two areas of said read only area and said recording/reproducing area, and
wherein a push-pull signal output T 1 reproduced from said read only area is more than 0.1 and another push-pull signal output T 2 reproduced from said recording/reproducing area is more than 0.1, and wherein 1.5≧T 1 /T 2 ≧0.5, and
wherein birefringence of said substrate is less than 100 nm by double paths.
2. An information recording medium comprising at least a substrate, a recording layer, and a resin layer,
wherein said substrate is formed with a read only area and a recording/reproducing area, and wherein said read only area and said recording/reproducing area do not overlap with each other, and
wherein a reflectivity of said recording layer is more than 10%, and
wherein said recording layer and said resin layer is formed continuously over at least two areas of said read only area and said recording/reproducing area, and
wherein a push-pull signal output T 1 reproduced from said read only area is more than 0.1 and another push-pull signal output T 2 reproduced from said recording/reproducing area is more than 0.1, and wherein 1.5≧T 1 /T 2 ≧0.5, and
wherein birefringence of said resin layer is less than 100 nm by double paths.
3. A reproducing method for reproducing an information recording medium comprising at least a substrate, a recording layer, and a resin layer,
wherein said substrate is formed with a pit corresponding to a read only area and a groove corresponding to a recording/reproducing area, and wherein said pit and said groove do not overlap with each other, and
wherein a reflectivity of said recording layer is more than 10%, and
wherein said recording layer and said resin layer are formed continuously over at least two areas of said read only area and said recording/reproducing area, and
wherein a push-pull signal output T 1 reproduced from said read only area is more than 0.1 and another push-pull signal output T 2 reproduced from said recording/reproducing area is more than 0.1, and wherein 1.5≧T 1 /T 2 ≧0.5, and
wherein the information recording medium is reproduced by irradiating a laser beam on said recording layer through a pickup equipped with a lens having a numerical aperture NA of any one selected out from 0.4 to 0.9.