Patent ID: 9304290
Filing Date: 2016-04-05
CPC Classification: G02B

Claim Text:
1. An imaging lens comprising a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element arranged in order from an object side to an image side along an optical axis of said imaging lens, each of said first lens element, said second lens element, said third lens element, said fourth lens element and said fifth lens element having an object-side surface facing toward the object side, and an image-side surface facing toward the image side, wherein: said object-side surface of said first lens element has a convex portion in a vicinity of the optical axis; said object-side surface of said second lens element has a convex portion in a vicinity of a periphery of said second lens element, and said image-side surface of said second lens element has a concave portion in a vicinity of the periphery of said second lens element; said image-side surface of said third lens element has a convex portion in a vicinity of the optical axis; said image-side surface of said fourth lens element has a concave portion in a vicinity of a periphery of said fourth lens element; said fifth lens element has a positive refractive power and is made of a plastic material, said object-side surface of said fifth lens element having a convex portion in a vicinity of a periphery of said fifth lens element; and said imaging lens does not include any lens element with refractive power other than said first lens element, said second lens element, said third lens element, said fourth lens element and said fifth lens element, wherein the imaging lens satisfies EFL/AC23≦0.7, where EFL represents a system focal length of said imaging lens and AC23 represents an air gap length between said second lens element and said third lens element at the optical axis.