Mobile device and optical imaging lens thereof

摘要

The present invention provides a mobile device and an optical imaging lens thereof. The optical imaging lens comprises an aperture stop, first, second, third and fourth lens elements positioned sequentially from an object side to an image side. The first lens element with positive refracting power has a surface facing toward the object side. The second lens element with negative refracting power has a convex surface facing toward the object. The third lens element has a positive refracting power. The fourth lens element has a surface facing toward the object side with a concave portion in the vicinity of the optical axis and a surface facing toward the image side with a convex portion in the peripheral vicinity. The optical imaging lens of the present invention is capable of shortening the total length of the optical imaging lens efficiently and has good optical characteristics.

主权项

1. An optical imaging lens, sequentially from an object side to an image side, comprises:
an aperture stop; and first, second, third and fourth lens elements, each of said first, second, third, and fourth 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, said object-side surface thereof comprises a convex portion in a vicinity of the optical axis; said second lens element has negative refracting power, said object-side surface thereof is a convex surface, and said image-side surface thereof comprises a concave portion in a vicinity of the optical axis; said third lens element has positive refracting power; said object-side surface of said fourth lens element comprises a convex portion in a vicinity of the optical axis, and said image-side surface of said fourth lens element comprises a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the fourth lens element; the optical imaging lens as a whole has refracting power, the sum of the thickness of all four lens elements along the optical axis is ALT, the sum of all three air gaps from the first lens element to the fourth lens element along the optical axis is Gaa, and ALT and Gaa satisfy the relation:
0.26≦(Gaa/ALT)≦0.65; and a central thickness of the first lens element along the optical axis is T1, a central thickness of the third lens element along the optical axis is T3, a central thickness of the fourth lens element along the optical axis is T4, an air gap between the third lens element and the fourth lens element along the optical axis is G34, and T1, T3, T4, and G34 satisfy the relations:
1.8≦[(T1+T3)/T4]≦3 and (T3/G34)≦10.