Objective lens for optical pick-up apparatus and optical pick-up apparatus

摘要

An objective lens for use in an optical pickup apparatus in which first and second light sources are provided on a same flat surface, converges each of the light fluxes from the first and second light sources onto an information recording plane through each of transparent substrates of a first and second optical information recording mediums and has a coma aberration of 0.015 lambd1 rms or less when recording or reproducing information is conducted for the first optical information recording medium, and a coma aberration of 0.015 lambd2 rms or less when recording or reproducing information is conducted for the second optical information recording medium.