Optical recording medium, disc system and apparatus

摘要

The present invention relates for a recordable optical disc, which comprises a recordable layer (43) onto which a laser beam is converged by an objective lens (2) having a numerical aperture (NA) falling within a range of about 0.55 to 0.70, and a light-transmitting substrate (41) supporting the recordable layer (43), the light-transmitting substrate (41) having a thickness falling within a range of about 0.1 to 0.6 mm and transmitting the laser beam therethrough to and converged on the recordable layer (43).