US Patent 9857558 Optical imaging lens

Present embodiments provide for an optical imaging lens. The optical imaging lens comprises a first lens element, a second lens element, a third lens element and a fourth lens element positioned in an order from an object side to an image side. Through controlling the convex or concave shape of the surfaces of the lens elements and designing parameters satisfying at least one inequality, the optical imaging lens shows better optical characteristics and enlarge field angle while the total length of the optical imaging lens is shortened.