Imaging lens, and electronic apparatus including the same

摘要

An imaging lens includes first to fourth lens elements arranged from an object side to an image side in the given order. Through designs of surfaces of the lens elements and relevant lens parameters, a short system length of the imaging lens may be achieved while maintaining good optical performance.

主权项

1. An imaging lens comprising a first lens element, a second lens element, a third lens element and a fourth 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 and said fourth 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 image-side surface of said first lens element has a concave portion in a vicinity of a periphery of said first lens element; said second lens element has a positive refractive power; said image-side surface of said third lens element has a convex portion in a vicinity of the optical axis; said fourth lens element has a negative refractive power, and said image-side surface of said fourth lens element has a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of said fourth lens element; said imaging lens does not include any lens element with refractive power other than said first lens element, said second lens element, said third lens element and said fourth lens element; and said imaging lens satisfies 2.5≦BFL/G23≦6.5 and 3.9≦BFL/G12≦17, where BFL represents a distance at the optical axis between said image-side surface of said fourth lens element and an image plane at the image side, G23 represents an air gap length between said second lens element and said third lens element at the optical axis, and G12 represents an air gap length between said first lens element and said second lens element at the optical axis.