US Patent 8477432 Image lens with low chromatic aberration and high resolution

An image lens for imaging an object on an image plane, in the order from the object side to the image side thereof, includes: a first lens with negative refraction power, a second lens with positive refraction power, a third lens with negative refraction power, a fourth lens with positive refraction power, and a fifth lens. The image lens satisfies the following formula: 0.9<F2/F<1.4; wherein F2 is focal length from the second lens to the fourth lens, F is focal length of the image lens.