US Patent 10409033 Lens assembly

A lens assembly includes a first lens, a second lens, a third lens, and a fourth lens, wherein the first lens, the second lens, the third lens, and the fourth lens are arranged in order from an object side to an image side along an optical axis. The first lens is with positive refractive power. The second lens is with negative refractive power. The third lens is with refractive power. The fourth lens is with negative refractive power. The lens assembly satisfies: 0.2<D4/TTL<0.6, wherein D4 is an effective diameter of the fourth lens and TTL is an interval from an object side surface of the first lens to an image plane along the optical axis.