Apparatus for reproducing optical information contained on disks of various recording densities

摘要

An apparatus is disclosed that reproduces data recorded on a recording medium having a plurality of pits formed in the medium that stores the data. The medium is designed to be compatible with an information reproducing apparatus having a lens with a first numerical aperture NA1 for focusing a laser beam of a first wavelength lambda 1 on the recording medium. The apparatus of the present invention comprises a laser generator for generating a laser beam of a second wavelength lambda 2 and a lens having a second numerical aperture NA2 for focusing the laser beam from the laser generator. The second wavelength lambda 2 of the laser beam and the second numerical aperture NA2 of the lens are set to satisfy the relationship: ( lambda 2/NA2)<( lambda 1/NA1).