MULTILAYERED INFORMATION RECORDING MEDIUM AND AN INFORMATION RECORDING/REPRODUCING DEVICE, SPECIFICALLY WITH REGARDS TO COMPRISING PLURAL RECORDING LAYERS LAMINATED AT SPACER LAYERS

摘要

PURPOSE: A multilayered information recording medium and an information recording/reproducing device are provided to supply a cover layer having an optical path length equal to a cover layer of a single-layered disk to other recording layer disposed at a thinner cover layer, thereby realizing an excellent disk stability and continuously reproducing signals when recording information. CONSTITUTION: A multilayered information recording medium can be compatible with a single-layered information recording medium in terms of reproducing/recording conditions. The single-layered information recording medium comprises a cover layer having a predetermined refractive index 'n' and a thickness 't' at a recording layer of a light incident surface. The multilayered information recording medium includes the deepest recording layer from the light incident surface. The deepest recording layer is formed at an optical distance(d1) from the light incident surface which satisfies a condition 'd=nt'. The multilayered information recording medium includes at least one shallow recording layer formed at an optical distance(d2) which satisfies a condition 'd