Patent ID: 8503108
Filing Date: 2013-08-06
Classification: G02B

Abstract:
1. A photographing 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; a second lens element with negative refractive power, wherein at least one of an object-side surface and an image-side surface of the second lens element is aspheric; a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface, wherein the third lens element has at least one aspheric surface; and a fourth lens element with negative refractive power having a concave object-side surface and made of plastic material, wherein the object-side surface and an image-side surface of the fourth lens element are aspheric, and the fourth lens element has at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof; wherein the photographing optical lens assembly has four lens elements with refractive power, a radius of curvature of the object-side surface of the fourth lens element is R7, a focal length of the photographing optical lens assembly is f, a focal length of the first lens element is f1, a focal length of the third lens element is f3, a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the mage-side surface of the second lens element is R4, and the photographing optical lens assembly further comprises an aperture stop which is located between an imaged object and the first lens element, wherein a distance on the optical axis between the aperture stop and an image plane is SL, a distance on the optical axis between the object-side surface of the first lens element and the image plane is TTL, a focal length of the fourth lens element is f4, and they satisfy the following relationships: