Imaging optical system, and imaging apparatus incorporating the same

摘要

An imaging optical system including, from the object side to the image side, a first lens group having positive refracting power, an aperture stop, and a second lens group having positive power, in which the first lens group consists of three lens subgroups, having positive, negative and positive refracting powers, respectively, from the object side to the image side, with satisfaction of the following:
4<(LTL+fB)/fB<15  (1)0.3where fB is an on-axis distance, from an image side-surface in the second lens group to an image plane upon focusing at infinity, LTL is an on-axis distance from an object side-surface in the first lens group to the image side-surface in the second lens group, D12 is an on-axis length from an image side-surface in the first lens group to an object side-surface in the second lens group upon focusing at infinity, and IH is a maximum image height.

主权项

1. An imaging optical system comprising, in order from an object side to an image side,
a first lens group having positive refracting power, an aperture stop, and a second lens group having positive refracting power, wherein: there is no lens group other than said first lens group and said second lens group, said first lens group consists of three lens subgroups: in order from the object side to the image side, a first lens subgroup having positive refracting power, a second lens subgroup having negative refracting power, and a third lens subgroup having positive refracting power, with satisfaction of the following Conditions (1) and (2):
4<(LTL+fB)/fB<15  (1)0.3