Patent ID: 8031574
Filing Date: 2011-10-04
Classification: G11B

Abstract:
1. An information recording medium onto which information is to be recorded and/or from which information is to be reproduced using a laser beam, the information recording medium comprising: a first information recording layer formed at a laser beam entrance surface of the medium and configured so that information can be recorded thereupon and/or reproduced therefrom using near-field light with a first objective lens having a first numerical aperture NA a second information recording layer formed so as to have a distance to the laser beam entrance surface of 0.05 mm to 1.2 mm and configured so that information can be recorded thereupon and/or reproduced therefrom using a second objective lens having a second numerical aperture NA wherein: when a diffraction limit δ the distance from the second information recording layer to the laser beam entrance surface is set in a range of 0.06 mm to 0.11 mm; an amount of data recorded onto the first information recording layer and the second information recording layer is no more than 25 Gbyte for each of the layers; and the second information recording layer is single-layer.