Patent ID: 9335520
Filing Date: 2016-05-10
CPC Classification: G02B

Claim Text:
1. An imaging lens comprising an aperture stop, 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 a refractive power, an object-side surface facing toward the object side, and an image-side surface facing toward the image side, wherein: said imaging lens comprises only five lens elements; said image-side surface of said first lens element has a convex portion in a vicinity of a periphery of said first lens element; said object-side surface of said second lens element has a concave 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 optical axis, and a convex portion in a vicinity of said periphery of said second lens element; said object-side surface of said third lens element has a concave portion in a vicinity of a periphery of said third lens element; said fourth lens element has a positive refractive power, and said object-side surface of said fourth lens element has a concave portion in a vicinity of the optical axis; said object-side surface of said fifth lens element has a convex portion in a vicinity of the optical axis; said imaging lens satisfies T5/G23≧1.1 and G45>G34, where G23 represents an air gap length between said second lens element and said third lens element at the optical axis, G34 represents an air gap length between said third lens element and said fourth lens element at the optical axis, G45 represents an air gap length between said fourth lens element and said fifth lens element at the optical axis, and T5 represents a thickness of said fifth lens element at the optical axis; and said imaging lens further satisfies Gaa/T3≧2.3, where Gaa represents a sum of four air gap lengths among said first lens element, said second lens element, said third lens element, said fourth lens element and said fifth lens element at the optical axis, and T3 represents the thickness of said third lens element at the optical axis.