NEAR-INFRARED LENS FOR CAMERAS IN MOBILE DEVICES

摘要

A first optical imaging system includes, in order from the object side to the image side, a first lens element, a second lens element, and a third lens element, arranged along an optical axis. A second optical imaging system includes, in order from the object side to the image side, a first lens element, a second lens element, a third lens element, and a fourth lens element, arranged along an optical axis. A third optical imaging system is a telecentric lens system having only lens elements having a refractive power and a chief ray angle smaller than 1 degree. The lens elements of the optical imaging systems may be made of the same material having absorption in visible wavelengths and high transmission in near infrared radiation. The lens elements may be coated with an antireflective coating that is optimized for near infrared radiation.

主权项

1. An optical imaging lens system comprising, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, and a fourth lens element arranged along an optical axis, each of the 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:
the second lens element has a positive refractive power, the object-side surface of the second lens element comprises a convex portion in a vicinity of the optical axis, and the image-side surface of the second lens element comprises a concave portion in a vicinity of the optical axis; the object side of the third lens element comprises a concave portion in a vicinity of an outer circumference of the third lens element; wherein: a thickness of the first lens element is defined as T1 and a distance measured from the object side surface of the first lens element to the image plane along the optical axis is defined as TTL, and T1 and TTL satisfy the relation:
3.85≦TTL/T1≦7.00.