Patent ID: 9720209
Date: 2017-08-01
CPC Classifications: G02B

Claim:
1. An imaging lens consisting of, in order from the object side to the image side: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a stop; and a third lens group having a positive refractive power, the first lens group consisting of four lenses, the first lens group having a positive lens and a negative meniscus lens provided adjacent to each other in this order as lenses most toward the object side, and further a negative lens as a lens most toward the image side, the second lens group consisting of one single lens, the third lens group consisting of four lenses, the third lens group having four lenses having refractive powers of different signs adjacent to each other provided in order as lenses most toward the image side, and conditional formulae (1) and (2) below being satisfied wherein ν12ave is the average Abbe's number of all of the lenses within the first lens group and the second lens group with respect to the d line, f is the focal length of the entire lens system, and f12 is the combined focal length of the first lens group and the second lens group.