Information recording medium, information reproducing apparatus, information recording apparatus, and information recording/reproducing apparatus

Abstract

The depth of pits is determined by a trade-off between the level of a push-pull signal used for servo application by a push-pull method and the level of an RF signal as a reproduced signal of information. The depth d is set to be the optimum for a disk system, which has a refractive index n of a medium, an optical wavelength λ, and an optical system with a NA (Numerical Aperture) of 0.75. The most suitable depth d for both the push-pull signal level and the RF signal level falls within a range of λ/5.5 n≦d≦λ/4.7 n, the second most suitable depth d falls with a range of λ/5.5 n≦d≦λ/4.5 n, and the depth d as the widest standard falls within a range of λ/8 n≦d≦λ/4.5 n.

Dependencies are inferred from the claim text.