Patent ID: RE40136

Claim:
An optical disc comprising: a first information storage layer which is relatively reflective with respect to a first laser beam but is relatively transmissive with respect to a second laser beam, the wavelength of said second laser beam being shorter longer than the wavelength of said first laser beam, the information stored in said first information storage layer being readout by said first laser beam; a second information storage layer which reflects said second laser beam transmitted through said first information storage layer, the information stored in said second information storage layer being read-out by said second laser beam; and a light incidence surface onto and through which first and second laser beams are irradiated for read-out of the information from said first and second information storage layers, respectively, said light incidence surface being formed at one side of said optical disc, wherein, said first information storage layer and said second information storage layer are provided so as to be separated for separating the first and second laser beams reflected by said first information storage layer and said second information storage layer, and the length between said light incidence surface to said second information storage layer is substantially equal to the thickness of said optical disc.