Objective lens for optical recording media and optical pickup apparatus using the same

摘要

An objective lens for converging two wavelengths of light to their predetermined positions is constituted by two or three lenses. Respective materials for forming adjacent lenses are chosen such that the respective refractive indices of adjacent lenses substantially equal each other with respect to only one of the two wavelengths of light, whereas the form of each lens surface is configured so as to suppress aberration in the objective lens as a whole.