Imaging lens and imaging apparatus

摘要

The imaging lens substantially consists of a first lens group having positive refractive power, an aperture stop, and a second lens group having positive refractive power, in this order from the object side. The first lens group consists of, in this order from the object side, an eleventh lens group and a twelfth lens group with a largest air space therebetween. The eleventh lens group has at least one negative lens with a concave surface toward the image side, having negative refractive power; and the twelfth lens group has positive refractive power. The second lens group substantially consists of, in this order from the object side, an aspheric lens having at least one aspheric surface, a positive lens, a negative lens, and a three-cemented lens formed by cementing a positive lens, a negative lens, and a positive lens in this order from the object side.

主权项

1. An imaging lens substantially consisting of:
a first lens group having positive refractive power, an aperture stop, and a second lens group having positive refractive power, in this order from the object side,
the first lens group being composed of an eleventh lens group and a twelfth lens group, in this order from the object side, with a largest air space therebetween,the eleventh lens group having negative refractive power and consisting of at least one negative lens with a concave surface toward the image side,the twelfth lens group having positive refractive power, andthe second lens group comprising an aspheric lens having at least one aspheric surface and a three-cemented lens formed by a positive lens, a negative lens, and a positive lens in this order from the object side, wherein the imaging lens satisfies conditional expression (1) below:
Nd2>1.8  (1),where,
Nd2: the average value of the refractive index with respect to the d-line of the materials of positive lenses in the three-cemented lens.