Patent ID: 7143426

Claim:
An optical recording medium comprising a substrate, a protective layer, four or more information recording layers, a light incidence plane being constituted by the surface of either the substrate or the protective layer, the optical recording medium further comprising a first transparent intermediate layer formed between a first information recording layer farthest from the light incidence plane and a second information recording layer located on the side of the light incidence plane with respect to the first information recording layer, a second transparent intermediate layer formed between the second information recording layer and a third information recording layer located on the side of the light incidence plane with respect to the second information recording layer, and a third transparent intermediate layer formed between the third information recording layer and a fourth information recoding layer located on the side of the light incidence plane with respect to the third information recording layer wherein the first transparent intermediate layer, the second transparent intermediate layer, and the third transparent intermediate layer are formed so that a thickness Da of the first transparent intermediate layer is 20% to 40% of a total thickness (Da+Db+Dc) of the first transparent intermediate layer, the second transparent intermediate layer, and the third transparent intermediate layer, a thickness Db of the second transparent intermediate layer is 35% to 60% of the total thickness (Da+Db+Dc) of the first transparent intermediate layer, the second transparent intermediate layer and the third transparent intermediate layer, and a thickness Dc of the third transparent intermediate layer is 20% to 40% of the total thickness (Da+Db+Dc) of the first transparent intermediate layer, the second transparent intermediate layer and the third transparent intermediate layer.