OBJECTIVE LENS FOR OPTICAL PICKUP

摘要

PROBLEM TO BE SOLVED: To provide a high-performance and small objective lens for an optical pickup while securing a working distance with large numerical apertures. SOLUTION: The objective lens for the optical pickup that carries out reading/writing of information by condensing luminous flux from a light source on an information recording medium comprises two lenses consisting of a first lens having a first flat surface on the light source side and a second concave surface on the light source side, and a second lens having a third convex surface on the light source side and a fourth concave surface on the light source side, in this order from the light source side. The objective lens has at least one aspherical surface. The aspherical surface satisfies a predetermined condition.