Mobile device and optical imaging lens thereof

An optical imaging lens, the optical imaging lens comprising:

• sequentially from an object side to an image side along an optical axis, 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 object-side surface of said second lens element comprises a convex portion in a vicinity of a periphery of the second lens element;
• said object-side surface of said third lens element comprises a convex portion in a vicinity of the optical axis and a concave portion in a vicinity of a periphery of the third lens element;
• said fifth lens element is constructed by plastic, said object-side surface thereof comprises a concave portion in a vicinity of the optical axis, and said image-side surface thereof comprises a concave portion in a vicinity of the optical axis;
• and
• the optical imaging lens as a whole comprises only said five lens elements having refracting power,
• wherein an air gap between the second lens element and the third lens element along the optical axis is G23, an air gap between the third lens element and the fourth lens element along the optical axis is G34, and G23 and G34 satisfy the equation:
• 1.1≦G34/G23.