Patent ID: 9213165
Filing Date: 2015-12-15
Classification: G02B

Abstract:
1. A lens optical system comprising first, second, and third lenses that are arranged between an object and an image sensor where an image of the object is formed, in order from an object side, wherein the first lens has a positive (+) refractive power and is convex toward the object, the second lens has a negative (−) refractive power and is convex toward the image sensor, and the third lens has a positive (+) refractive power and at least one of an incident surface and an exit surface of the third lens has at least one inflection point between a center portion and an edge thereof, wherein the lens optical system satisfies the following inequalities, wherein f1 is a focal length of the first lens, f is a total focal length of the lens optical system, Vd1 is an Abbe number of the first lens, and Vd2 is an Abbe number of the second lens, wherein the first lens has a meniscus shape that is convex toward the object, wherein the lens optical system further comprises an aperture between the first and second lenses, wherein an incident surface and an exit surface of the second lens are aspherical, wherein the focal length (f1) of the first lens is smaller than 2.12 mm, and the focal length (f) of the lens optical system is smaller than 2.82 mm, and wherein a curvature radius of the incident surface of the second lens and a curvature radius of the exit surface of the second lens are negative.