Objective lens element and optical pickup device provided with its object lens element

Abstract

An optical pickup device has an optical source 101 for emitting an optical beam, an objective lens element 103 positioned to receive the optical beam for focusing the beam on a medium 104, wherein a position of the optical source 101 relative to a position of the objective lens element 103 is fixed, a combined movement of the objective lens element 103 and the optical source 101 focuses the optical beam on the medium 104; and the objective lens element 103 satisfies the following condition: −0.300≦m≦−0.200,   (1) where, m is an imaging magnification.

Dependencies are inferred from the claim text.