Patent ID: 8293352

Claim:
An optical recording medium comprising: a substrate; an information signal layer provided on the substrate; and a protective layer provided on the information signal layer, wherein the information signal layer is provided with a reflecting layer, a recording layer provided on the reflecting layer and a first dielectric layer, a second dielectric layer and a third dielectric layer laminated successively on the recording layer, refractive indexes of the first dielectric layer, the second dielectric layer and the third dielectric layer are different from each other between the adjacent dielectric layers to each other, among the first dielectric layer, the second dielectric layer and the third dielectric layer, the dielectric layer having the highest refractive index contains, as a main component, at least one member selected from the group consisting of titanium oxide, niobium oxide and a mixture of zinc sulfide and silicon oxide, and the dielectric layer having the highest refractive index has a refractive index of 2.3 or more at a wavelength of 405 nm, and when refractive indexes of the first dielectric layer, the second dielectric layer and the third dielectric layer are defined as n 1 , n 2 and n 3 , respectively, the refractive indexes n 1 , n 2 and n 3 are satisfied with a relationship of n 1 >n 2 >n 3 .