Patent ID: 7151639

Claim:
A thin-type spherical lens, comprising a light-entering face and a plurality of light-exiting faces corresponding to said light-entering face, wherein said light-entering face is a spherical surface, and said plurality of light-exiting faces are fabricated according to the result of the virtual procedures of removing the portion of each of a plurality of lens bodies with different radii of curvature of light-exiting faces, which corresponds to a spherical surface with the optical axis of said thin-type spherical lens as its central axis, and assembling the preserved portions to form a plurality of grooves as said plurality of light-exiting faces, and wherein the curvature radii of said plurality of light-exiting faces are designed to be different so that all the focal lengths of said plurality of light-exiting faces are identical; wherein the maximum aperture of said thin-type spherical lens is about twice the focal length thereof.