ZOOM LENS AND IMAGE PICKUP APPARATUS HAVING THE SAME

摘要

A zoom lens includes, in order from the object side, a positive first unit, a zooming lens group constituted by at least two lens units having a zooming function and a function of correcting image plane variation with zooming, and a last lens unit disposed on the most image side having an imaging effect and not moving for zooming. The first unit includes a negative first sub unit not moving for focusing, a second sub unit moving during focusing, and a positive third sub unit not moving for focusing. The first sub unit is composed of one or more concave lenses, and the third sub unit is composed of one or more convex lenses. Of the first and third sub units, the refractive powers, the average Abbe constants and the paraxial converted beam heights at the telephoto end are appropriately set.

主权项

1. A zoom lens comprising, in order from the object side to the image side:
a first lens unit having positive refractive power; a zoom lens group constituted by at least two lens units which move during zooming; and a last lens unit disposed on the most image side that does not move for zooming, wherein the first lens unit includes a first sub lens unit having negative refractive power that does not move for focusing, a second sub lens unit that moves during focusing, and a third sub lens unit having positive refractive power that does not move for focusing, the first sub unit is composed of one or more concave lenses, and the third sub lens unit is composed of one nor more convex lenses and, the zoom lens satisfies the following condition:-0.6<φ11φ13v11v13×(h11Th13T)2<-0.5,where φ11 is the refractive power of the first sub lens unit, φ13 is the refractive power of the third sub lens unit, ν11 is the average Abbe constant of the first sub lens unit, ν13 is the average Abbe constant of the third sub lens unit, h11T is the paraxial converted beam height of the first sub lens unit at the telephoto end, and h13T is the paraxial converted beam height of the third sub lens unit at the telephoto end.