Patent attributes
A lens assembly includes a first lens, a second lens, a third lens, and a fourth lens. The first lens is with positive refractive power and includes a concave surface facing an object side and a convex surface facing an image side. The second lens is with negative refractive power and includes a concave surface facing the object side. The third lens is with positive refractive power. The fourth lens is with refractive power and includes a concave surface facing the image side. The first lens, the second lens, the third lens, and the fourth lens are arranged in order from the object side to the image side along an optical axis. The lens assembly satisfies: TTL/f>1.2; wherein TTL is a total length of optical system of the lens assembly and f is an effective focal length of the lens assembly.
