Patent ID: 9239448
Filing Date: 2016-01-19
CPC Classification: G02B

Claim Text:
1. An imaging lens, consisting of, in the recited order from an object side: a negative first lens group consisting of only a first lens, which is a single biconcave lens; and a positive second lens group consisting of a cemented lens that is formed by bonding a second lens, which is a biconvex lens, and a third lens, which is a negative meniscus lens, in this order from the object side and that has a positive refractive power as a whole; an aperture stop; and a cemented lens that is formed by bonding a fourth lens which is a biconvex lens and a fifth lens which is a negative meniscus lens in this order from the object side and that has a positive refractive power as a whole, wherein the imaging lens satisfies conditional expression (5) given below: where: dsi: the distance (the back focus portion corresponds to the air conversion distance) between an aperture stop and an image formation surface on the optical axis; and f: the focal length of the entire lens system.