| 主权项 |
1. An imaging lens comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth 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, said fifth lens element and said sixth 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 first lens element has a positive refractive power; said second lens element is made of a plastic material; said image-side surface of said third lens element has a concave portion in a vicinity of the optical axis; 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 image-side surface of said fifth lens element has a concave portion in a vicinity of the optical axis; said image-side surface of said sixth lens element has a convex portion in a vicinity of a periphery of said sixth lens element; said imaging lens does not include any lens element with a refractive power other than said first lens element, said second lens element, said third lens element, said fourth lens element, said fifth lens element and said sixth lens element, and said imaging lens further satisfies Gaa/T3≦3.60, where Gaa represents a sum of five air gap lengths among said first lens element, said second lens element, said third lens element, said fourth lens element, said fifth lens element and said sixth lens element at the optical axis, and T3 represents a thickness of said third lens element at the optical axis. |
