INFORMATION RECORDING MEDIUM AND RECORDING/REPRODUCING METHOD THEREOF

摘要

An information recording medium for reproducing information by irradiation with a laser beam condensed by an objective lens with a numerical aperture NA includes a disk-shaped substrate and a recording layer disposed on the substrate. On the surface of the substrate, a plurality of prepit regions (110) and a plurality of data regions (120) are disposed alternately along spiral or concentric virtual track centers. Each prepit region includes a pair of wobble pits (113) for tracking servo, and a length L ( mu m) of the wobble pit along the virtual track center, a wavelength lambda ( mu m) of the laser beam, and a numerical aperture NA satisfy a relationship: 0.3