Objective lens, optical pickup apparatus and recording and/or reproducing apparatus

摘要

An objective lens for recording and/or reproducing information of an optical information recording medium, comprises a first lens group having a positive refractive power; and a second lens group having a positive refractive power. The first and second lens groups are arranged in this order from a light source side of the objective lens and are made of a plastic material respectively; and the following formula is satisfied:NA > 0.85    where NA is a necessary image side numerical aperture for recording or reproducing information of the optical information recording medium.