WIDE-ANGLE LENS, OPTICAL DEVICE USING THE WIDE-ANGLE LENS, AND METHOD FOR FABRICATING THE WIDE-ANGLE LENS

摘要

An optical device comprises an object-side lens group (200), an image-side lens group (400), and a single or a plurality of converging lenses (300) disposed between the object-side lens group (200) and the image-side lens group (400). The object-side lens group (200) is configured as a single concave lens (210) having an incident surface (211) convex toward the object side or a plurality of the concave lenses combined with each other. The concave lens (210) has the incident surface (211) formed as a convex aspherical surface (211a) in which its curvature tends to increase with respect to the curvature at the center of the optical axis as approaching the periphery and an exit surface (212) formed as a substantially concave spherical surface.