| 主权项 |
1. An optical imaging lens, sequentially from an object side to an image side along an optical axis, comprising an aperture stop, first, second, third, fourth and fifth lens elements, each of said first, second, third, fourth and fifth lens elements having 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 positive refracting power, and said image-side surface thereof comprises a convex portion in a vicinity of a periphery of the first lens element; said second lens element has negative refracting power; said image-side surface of said third lens element comprises a concave portion in a vicinity of the optical axis; said fourth lens element has positive refracting power; said fifth lens element is constructed by plastic material, and said object-side surface thereof comprises a concave portion in a vicinity of the optical axis; the optical imaging lens as a whole has only the five lens elements having refracting power; and wherein a central thickness of the third lens element along the optical axis is CT3, a central thickness of the fifth lens element along the optical axis is CT5, and CT3 and CT5 satisfy the equation:
1.9≦CT5/CT3≦3.0; wherein a central thickness of the first lens element along the optical axis is CT1, an air gap between the second lens element and the third lens element along the optical axis is AG23, and CT1 and AG23 satisfy the equation:
CT1/AG23 ≦1.6; and wherein said third lens element has negative refracting power. |
