Patent ID: 8749892
Filing Date: 2014-06-10
Classification: G02B

Abstract:
1. An optical system arranged along an optical axis, comprising: a first lens having a positive refractive power, having an object side surface of convex shape and an image side surface of concave shape; a second lens having an object side surface of convex shape and an image side surface of concave shape; a set of three lenses at least for adding chromatic correction and optical power for the optical system; and a sixth lens having positive refractive power; wherein: the optical system introduces an optical distortion to an image formed by the optical system that changes with field angle, the optical system comprises field curvature correction for a range of object distances and, the optical system substantially satisfies a condition: b_f/f<0.3065, wherein b_f is a back focal length of the optical system and wherein f is a combined focal length of the combination of the first lens, second lens, set of three lenses and sixth lens.