PURPOSE: To simplify construction and to facilitate production, by joining a transparent plastic joint layer on the spherical face on the light source side of a spherical glass lens by injection molding and making the surface of the transparent plastic joint layer aspherical as the 1st face.
CONSTITUTION: A condenser lens 1 for optical discs consists of a spherical glass lens 2 joined with a transparent plastic joint layer 3 on the spherical face on the light source side L.S thereof by injection molding and has the basic constitution wherein the surface of the layer 3 is made aspherical as the 1st face R1. A large-diameter condenser lens which is simple in construction and is easy to manufacture is made usable by the above-mentioned constitution and the inclination in the optical axis of the lens occuring in an fitting error is decreased.
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