US Patent 8670192 Imaging lens and imaging apparatus

An imaging lens consists of a negative first lens having a concave object-side surface, a positive second lens, a negative third lens, a positive fourth lens having a convex object-side surface, and a positive fifth lens, which are in this order from an object side. A stop is arranged between an image-side surface of the first lens and an object-side surface of the third lens. When the focal length of an entire system is f, and the focal length of the first lens is f1, and the focal length of the second lens is f2, the following formula is satisfied:−1.30<f1/f2>−0.65  (7).