Objective lens for optical disc

摘要

An objective lens for an optical disc includes a positive single lens, disposed between a light source and the optical disc. The objective lens has a first surface directed to the light source and a second surface directed to the optical disc. The first surface has a convex shape and both the first surface and the second surface are aspheric. The objective lens satisfies the following condition: 1.0<|R2/R1|<1.2, where R1 is the paraxial radius of curvature on the light source side surface and R2 is the paraxial radius of curvature on the optical disc side surface.