Patent ID: 6030678
Filing Date: 2000-02-29
Classification: G11B,Y10S,Y10T

Abstract:
A multi-layer optical disk in which a first information layer and a second information layer are laminated to form one sheet of an optical disk, comprising;a metal reflecting film formed in said first information layer and having a reflection factor of more than 90% relative to a first reproduction light with a wavelength range of 770 nm.about.830 nm, anda semi-transparent reflecting film formed in said second information layer film wherein a ratio ns.sub.2 /ns.sub.1 between respective real number portions of a refractive index ns.sub.1 relative to said first reproduction light and a refractive index ns.sub.2 relative to a second reproduction light with a wavelength range of 615 nm.about.655 nm is more than 1.05.