Patent ID: 8068290
Filing Date: 2011-11-29
Classification: G02B

Abstract:
1. An image pick-up optical lens assembly comprising, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface; a third lens element with positive refractive power having an object-side surface and a convex image-side surface, at least one of the surfaces thereof being aspheric; and a fourth lens element with negative refractive power having a convex object-side surface and a concave image-side surface, at least one of the surfaces thereof being aspheric; wherein the image pick-up optical lens assembly further comprises an aperture stop disposed between an object and the first lens element; wherein the number of lens elements with refractive power is four; and wherein a combined thickness of the lens elements with refractive power on an optical axis is a distance on the optical axis between the object-side surface of the first lens element and the image-side surface of the fourth lens element is Td, a radius of curvature of the object-side surface of the first lens element is R 1 , a radius of curvature of the image-side surface of the first lens element is R 2 , a focal length of the image pick-up optical lens assembly is f, a focal length of the second lens element is f 2 , a focal length of the third lens element is f 3 , a focal length of the fourth lens element is f 4 , a distance on the optical axis between the first lens element and the second lens element is T 12 , and they satisfy the relations: