US Patent 9678310 Imaging lens and imaging apparatus equipped with the imaging lens

An imaging lens is constituted essentially by four or more lenses, including, in order from the object side to the image side: a first lens having a positive refractive power; a second lens having a negative refractive power; and a plurality of other lenses. The conditional formulae below are satisfied.0.8<TL/f<1.0  (1)1.0<f/fl<3.0  (2)2.03 mm<f<5.16 mm  (3)1.0 mm<fl<3.0 mm  (4)wherein f is the focal length of the entire lens system, fl is the focal length of the first lens, TL is the distance along the optical axis from the surface of the first lens toward the object side to the paraxial focal point position at the image side in the case that the portion corresponding to back focus is an air converted length.