Patent ID: 6807142
Filing Date: 2004-10-19
Classification: G11B

Abstract:
An optical information recording medium comprisinga substrate and at least a first information layer and a second information layer, the first information layer and second information layer, on/from which signals can be recorded/reproduced, being formed on the substrate in this order, wherein an area where the first information layer exists and the second information layer does not exist is provided on the substrate, the first information layer includes a first recording layer and the second information layer includes a second recording layer, and the first and second recording layers are formed of a material that changes reversibly between an amorphous state and a crystalline state by irradiation of a laser beam from a side of the substrate, and with respect to a laser bearn having a wavelength of &lgr;0 radiated from the side of the substrate for reproducing signals recorded on the first and second recording layers, a reflectance R0(1amo) of the first information layer when the first recording layer is in an amorphous state, a reflectance R0(1cry) of the first information layer when the first recording layer is in a crystalline state, a reflectance R0(2amo) of the second information layer when the second recording layer is in an amorphous state, and a reflectance R0(2cry) of the second information layer when the second recording layer is in a crystalline state satisfy the relationships: R0(1amo)<R0(1cry), and R0(2amo)>R0(2cry).