US Patent 10983306 Optical imaging system

An optical imaging system includes a first lens, a second lens, a third lens including a concave object side surface, a fourth lens, a fifth lens, and a sixth lens sequentially disposed from an object side toward an image side. The optical imaging system satisfies 0.7<TL/f<1.0 and F No.<2.1, where TL is a distance from an object side of the first lens to an imaging plane, f is a total focal length of the optical imaging system, and F No. is the F No. of the optical imaging system.