Patent ID: 9176306
Filing Date: 2015-11-03
Classification: G02B

Abstract:
1. An imaging lens, consisting essentially of a first lens group having a negative refractive power and a second lens group having a positive refractive power, disposed in order from the object side, wherein: the first lens group is composed of a first group first lens which is a single lens having a biconcave shape and a negative refractive power; the second lens group is composed of a second group first lens having a positive refractive power, an aperture stop, a second group second lens having a positive refractive power, and a second group third lens having a negative refractive power, disposed in order from the object side; the second group second lens and the second group third lens are cemented together to form a cemented lens; and the imaging lens satisfies a conditional expression (4a′) given below: where: f1: the focal length of the first group first lens; and f2: the focal length of the second group first lens, wherein