Patent ID: 9170399
Filing Date: 2015-10-27
Classification: G02B

Abstract:
1. An imaging lens consisting of: a first lens group; a stop; and a second lens group in this order from an object side, wherein the first lens group consists of a 1-1st lens having negative refractive power and a meniscus shape with a convex surface facing the object side and a 1-2nd lens having positive refractive power, and an object-side lens surface of which has a convex shape facing the object side, in this order from the object side, and wherein the second lens group consists of a 2-1st lens having positive refractive power and a meniscus shape with a convex surface facing an image side, a 2-2nd lens having negative refractive power, and an object-side lens surface of which has a concave shape facing the object side, and an absolute value of a curvature radius of the object-side lens surface of which is less than an absolute value of a curvature radius of an image-side lens surface thereof, and a 2-3rd lens having positive refractive power, and an object-side lens surface of which has a convex shape facing the object side, in this order from the object side, and wherein the following conditional formula (5) is satisfied: Ndp: an average of refractive indices of the 1-2nd lens, the 2-1st lens and the 2-3rd lens for d-line, and wherein the first lens group has a distance from the second lens group that is fixed at all times.