Patent ID: 9645363
Date: 2017-05-09
CPC Classifications: G02B

Claim:
1. An image capturing optical system, comprising, in order from an object side to an image side: a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof; a second lens element with negative refractive power having an object-side surface being concave in a paraxial region thereof; a third lens element; a fourth lens element having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in the paraxial region thereof, the object-side surface and the image-side surface thereof being aspheric; and a fifth lens element having an image-side surface being concave in a paraxial region thereof, an object-side surface and the image-side surface thereof being aspheric, at least one of the object-side surface and the image-side surface having at least one convex shape in an off-axis region thereof; wherein the image capturing optical system has a total of five lens elements and an air gap is arranged between every two adjacent lens elements; wherein a focal length of the second lens element is f2, a focal length of the first lens element is f1, a curvature radius of the object-side surface of the second lens element is R3, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, and the following conditions are satisfied: