Patent ID: 9019623
Filing Date: 2015-04-28
Classification: G02B

Abstract:
1. An imaging lens substantially consisting of a front group having positive refractive power, an aperture stop, and a rear group having positive refractive power in this order from the object side, wherein the front group includes two positive meniscus lenses with convex surfaces toward the object side, and one negative meniscus lens with a convex surface toward the object side; the rear group includes an aspheric lens and a three-cemented lens in this order from the object side; the three-cemented lens is formed by cementing a positive lens with a convex surface toward the image side, a negative lens, and a positive lens with a convex surface toward the image side, in this order from the object side; and conditional expression (1) below is satisfied: where Nd2: an average value of the refractive index with respect to the d-line of positive lenses within the three-cemented lens.